U.S. patent application number 16/749504 was filed with the patent office on 2020-05-21 for physical quantity measurement device and measurement control device.
The applicant listed for this patent is DENSO CORPORATION. Invention is credited to Takashi ENOMOTO, Masaki INOUE, Noboru KITAHARA, Hajime MASHITA, Hiroshi TAGAWA, Junzo YAMAGUCHI.
Application Number | 20200158550 16/749504 |
Document ID | / |
Family ID | 65368456 |
Filed Date | 2020-05-21 |
![](/patent/app/20200158550/US20200158550A1-20200521-D00000.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00001.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00002.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00003.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00004.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00005.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00006.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00007.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00008.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00009.png)
![](/patent/app/20200158550/US20200158550A1-20200521-D00010.png)
View All Diagrams
United States Patent
Application |
20200158550 |
Kind Code |
A1 |
YAMAGUCHI; Junzo ; et
al. |
May 21, 2020 |
PHYSICAL QUANTITY MEASUREMENT DEVICE AND MEASUREMENT CONTROL
DEVICE
Abstract
An air flow meter includes an inward part that is positioned
inward of an intake pipe and an outward part that is positioned not
inward but outward of the intake pipe. The air flow meter further
includes a first detector provided in the inward part, and a second
detector provided at a position closer to the outward part than the
first detector.
Inventors: |
YAMAGUCHI; Junzo;
(Kariya-city, JP) ; KITAHARA; Noboru;
(Kariya-city, JP) ; TAGAWA; Hiroshi; (Kariya-city,
JP) ; INOUE; Masaki; (Kariya-city, JP) ;
MASHITA; Hajime; (Kariya-city, JP) ; ENOMOTO;
Takashi; (Kariya-city, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENSO CORPORATION |
Kariya-city |
|
JP |
|
|
Family ID: |
65368456 |
Appl. No.: |
16/749504 |
Filed: |
January 22, 2020 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2018/025186 |
Jul 3, 2018 |
|
|
|
16749504 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01F 1/6847 20130101;
G01F 15/185 20130101; F02M 35/10386 20130101; G01F 1/6842 20130101;
G01F 15/022 20130101; F02D 41/18 20130101; G01K 13/02 20130101;
G01F 1/696 20130101; G01K 2013/024 20130101; G01F 5/00 20130101;
G01F 1/6965 20130101; G01F 15/14 20130101; G01F 15/16 20130101;
G01F 1/68 20130101 |
International
Class: |
G01F 15/02 20060101
G01F015/02; G01K 13/02 20060101 G01K013/02; G01F 1/68 20060101
G01F001/68; G01F 5/00 20060101 G01F005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 24, 2017 |
JP |
2017-142855 |
Dec 25, 2017 |
JP |
2017-247429 |
Claims
1. A physical quantity measurement device for measuring a physical
quantity of a fluid, comprising: a measurement flow channel through
which the fluid as a measurement target flows; a housing that forms
the measurement flow channel and is attached to a predetermined
attaching target in a state where at least a part of the housing is
positioned inward of the attaching target; a physical quantity
detector that detects a physical quantity of the fluid in the
measurement flow channel; a same kind-quantity detector that
detects, in an interior of the housing, a physical quantity of the
same kind as the physical quantity detected by the physical
quantity detector, the physical quantity detected by the same
kind-quantity detector being a correction parameter used for
correcting a detection result of the physical quantity detector; an
inward part that is positioned inward of the attaching target; and
an outward part that is positioned outward of the attaching target
without being positioned inward of the attaching target, wherein
the physical quantity detector is provided at a position included
in the inward part, and the same kind-quantity detector is provided
at a position closer to the outward part than the physical quantity
detector is in an alignment direction along which the inward part
and the outward part are aligned.
2. The physical quantity measurement device according to claim 1,
wherein the same kind-quantity detector is provided at a position
included in the inward part together with the physical quantity
detector.
3. The physical quantity measurement device according to claim 1,
further comprising a detection unit provided inside the housing,
wherein the physical quantity detector and the same kind-quantity
detector are both included in the detection unit.
4. The physical quantity measurement device according to claim 1,
further comprising a different kind-quantity detector that detects,
in the interior of the housing, a physical quantity of a different
kind from the physical quantity detected by the physical quantity
detector, the physical quantity detected by the different
kind-quantity detector being a correction parameter used for
correction of a detection result of the physical quantity
detector.
5. The physical quantity measurement device according to claim 4,
wherein the physical quantity detector and the different
kind-quantity detector are both provided in the measurement flow
channel.
6. The physical quantity measurement device according to claim 4,
wherein the physical quantity detector is a temperature detector
that detects a temperature as a physical quantity of the fluid, and
the different kind-quantity detector is a flow rate detector that
detects a flow rate as the physical quantity of the fluid.
7. A measurement control device for controlling a physical quantity
measurement device, the physical quantity measurement device
comprising: a measurement flow channel through which a fluid as a
measurement target flows; a housing that forms the measurement flow
channel and is attached to a predetermined attaching target in a
state where at least a part of the housing is positioned inward of
a predetermined attaching target; a physical quantity detector that
detects a physical quantity of the fluid in the measurement flow
channel; a same kind-quantity detector that detects, in an interior
of the housing, a physical quantity of the same kind as the
physical quantity detected by the physical quantity detector; an
inward part that is positioned inward of the attaching target; and
an outward part that is positioned outward of the attaching target
without being positioned inward of the attaching target, wherein
the physical quantity detector is provided at a position included
in the inward part, the same kind-quantity detector is provided at
a position closer to the outward part than the physical quantity
detector is in an alignment direction along which the inward part
and the outward part are aligned, and the measurement control
device further comprises a physical quantity correction unit that
corrects a detection result of the physical quantity detector based
on a detection result of the same kind-quantity detector.
8. The measurement control device according to claim 7, wherein the
physical quantity correction unit includes a differential
correction unit that acquires a differential correction amount for
correcting the detection result of the physical quantity detector
based on a difference between the detection result of the physical
quantity detector and the detection result of the same
kind-quantity detector.
9. The measurement control device according to claim 8, wherein the
differential correction unit increases the differential correction
amount with increase of the difference.
10. The measurement control device according to claim 7, wherein
the physical quantity correction unit includes a change correction
unit that corrects the detection result of the physical quantity
detector based on a behavior of change of the detection result of
the physical quantity detector.
11. The measurement control device according to claim 7, wherein
the physical quantity measurement device includes a different
kind-quantity detector that detects a physical quantity of a
different kind from the physical quantity detected by the physical
quantity detector and the same kind-quantity detector, and the
physical quantity correction unit includes a different
king-quantity correction unit that corrects the detection result of
the physical quantity detector based on a detection result of the
different kind-quantity detector in addition to the detection
result of the same kind-quantity detector.
12. The measurement control device according to claim 7, wherein
the physical quantity detector and the same kind-quantity detector
are each a temperature detector that detects a temperature as the
physical quantity of the fluid.
13. A measurement control device for controlling a physical
quantity measurement device, the physical quantity measurement
device including: a measurement flow channel through which a fluid
as a measurement target flows; a housing that forms the measurement
flow channel and is attached to a predetermined attaching target;
and a physical quantity detector that detects a physical quantity
of the fluid in the measurement flow channel, the measurement
control device comprising a controller configured to correct a
detection result of the physical quantity detector based on a
behavior of change of the detection result of the physical quantity
detector.
14. The measurement control device according to claim 13, wherein
the physical quantity measurement device includes a different
kind-quantity detector that detects a physical quantity of a
different kind from the physical quantity detected by the physical
quantity detector, and the controller corrects the detection result
of the physical quantity detector based on a detection result of
the different kind-quantity detector in addition to the behavior of
change of the detection result of the physical quantity
detector.
15. The measurement control device according to claim 14, wherein
the physical quantity detector is a temperature detector that
detects a temperature as the physical quantity of the fluid, the
different kind-quantity detector is a flow rate detector that
detects a flow rate as the physical quantity of the fluid, and the
controller corrects a temperature signal, which is the detection
result of the physical quantity detector, based on a behavior of
change of the temperature signal and a flow rate signal which is
the detection result of the different kind-quantity detector.
16. The measurement control device according to claim 15, wherein
the controller increases a flow rate correction amount with
decrease in flow rate which is the detection result of the
different kind-quantity detector, for correcting the temperature
which is the detection result of the physical quantity detector.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation application of
International Patent Application No. PCT/JP2018/025186 filed on
Jul. 3, 2018, which designated the U.S. and claims the benefit of
priority from Japanese Patent Application No. 2017-142855 filed on
Jul. 24, 2017, and Japanese Patent Application No. 2017-247429
filed on Dec. 25, 2017. The entire disclosures of all of the above
applications are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a physical quantity
measurement device and a measurement control device.
BACKGROUND
[0003] A physical quantity measurement device measures a flow rate
of intake air taken into an internal combustion engine. The
physical quantity measurement device includes a main passage
through which an inflow fluid passes, and a bypass passage branched
from the main passage. A flow rate detector for outputting a
detection signal corresponding to the flow rate of intake air is
provided in the bypass passage.
SUMMARY
[0004] According to at least one embodiment of the present
disclosure, a physical quantity measurement device measures a
physical quantity of a fluid. The physical quantity measurement
device includes a measurement flow channel through which the fluid
as a measurement target flows, and a housing that forms the
measurement flow channel and is attached to a predetermined
attaching target in a state where at least a part of the housing is
positioned inward of the attaching target. The physical quantity
measurement device includes a physical quantity detector that
detects a physical quantity of the fluid in the measurement flow
channel, and a same kind-quantity detector that detects, in an
interior of the housing, a physical quantity of the same kind as
the physical quantity detected by the physical quantity detector.
The physical quantity detected by the same kind-quantity detector
is a correction parameter used for correcting a detection result of
the physical quantity detector. The physical quantity measurement
device includes an inward part that is positioned inward of the
attaching target, and an outward part that is positioned outward of
the attaching target without being positioned inward of the
attaching target. The physical quantity detector is provided at a
position included in the inward part. The same kind-quantity
detector is provided at a position closer to the outward part than
the physical quantity detector is in an alignment direction along
which the inward part and the outward part are aligned.
BRIEF DESCRIPTION OF DRAWINGS
[0005] FIG. 1 is a schematic diagram illustrating a configuration
of a combustion system according to a first embodiment.
[0006] FIG. 2 is a front view of an air flow meter in a state of
being attached to an intake pipe.
[0007] FIG. 3 is a top view of an air flow meter in a state of
being attached to the intake pipe.
[0008] FIG. 4 is a perspective view of the air flow meter as seen
from an upstream-side end face of the air flow meter.
[0009] FIG. 5 is a perspective view of the air flow meter as seen
from a downstream-side end face of the air flow meter.
[0010] FIG. 6 is a side view of the air flow meter as viewed from a
connector portion side.
[0011] FIG. 7 is a side view of the air flow meter as viewed from a
side opposite to the connector portion.
[0012] FIG. 8 is a cross-sectional view taken along a line
VIII-VIII of FIG. 2.
[0013] FIG. 9 is an enlarged view of a periphery of a measurement
flow channel of FIG. 8.
[0014] FIG. 10 is a front view showing a configuration of a sensor
SA.
[0015] FIG. 11 is a cross-sectional view taken along a line XI-XI
of FIG. 8.
[0016] FIG. 12 is a cross-sectional view taken along a line XII-XII
of FIG. 8.
[0017] FIG. 13 is a cross-sectional view taken along a line
XIII-XIII of FIG. 8.
[0018] FIG. 14 is a cross-sectional view taken along a line XIV-XIV
of FIG. 8.
[0019] FIG. 15 is a horizontal cross-sectional view of a housing
before the sensor SA is inserted into the housing.
[0020] FIG. 16 is a horizontal cross-sectional view of the sensor
SA prior to insertion into the housing.
[0021] FIG. 17 is a vertical cross-sectional view showing an
internal configuration of the sensor SA.
[0022] FIG. 18 is a diagram illustrating a connection structure
between a connector terminal and a lead terminal of the sensor
SA.
[0023] FIG. 19 is a perspective view showing an internal structure
of a sealing region.
[0024] FIG. 20 is a perspective view of a terminal unit.
[0025] FIG. 21 is an enlarged view of a periphery of a lip in FIG.
8.
[0026] FIG. 22 is an exploded perspective view of a mold
device.
[0027] FIG. 23 is a diagram illustrating molding of a measurement
flow channel by a measurement molding portion.
[0028] FIG. 24 is a view showing a state in which the measurement
molding portion is removed from the housing.
[0029] FIG. 25 is a diagram illustrating molding of a passage flow
channel by a passage mold portion.
[0030] FIG. 26 is a view showing a state in which the passage mold
portion and the measurement molding portion are removed from the
housing.
[0031] FIG. 27 is a side view of an air flow meter in a
configuration group B as viewed from a connector portion side.
[0032] FIG. 28 is a cross-sectional view taken along a line
XXVIII-XXVIII of FIG. 27.
[0033] FIG. 29 is an enlarged view of a periphery of a sensor SA in
FIG. 8 in a configuration group C.
[0034] FIG. 30 is a cross-sectional view taken along a line XXX-XXX
of FIG. 29.
[0035] FIG. 31 is a cross-sectional view taken along a line
XXXI-XXXI of FIG. 29.
[0036] FIG. 32 is a view showing a state in which the measurement
molding portion and the passage mold portion are removed from the
housing in a configuration group D.
[0037] FIG. 33 is a diagram illustrating the molding of the passage
flow channel by the measurement molding portion and the passage
mold portion.
[0038] FIG. 34 is an enlarged view of a periphery of the sensor SA
in FIG. 30 in a configuration group E.
[0039] FIG. 35 is a top view of the air flow meter showing an
internal structure of the housing.
[0040] FIG. 36 is an enlarged view of the periphery of the
connector mold portion in a mold device.
[0041] FIG. 37 is a view illustrating the attachment of the sensor
SA to the housing.
[0042] FIG. 38 is a diagram illustrating the attachment of a bridge
terminal to the sensor SA.
[0043] FIG. 39 is a diagram illustrating filling of a thermosetting
resin into an internal space of the housing.
[0044] FIG. 40 is a top view of the air flow meter in a
configuration group F.
[0045] FIG. 41 is a cross-sectional view taken along a line XLI-XLI
of FIG. 40.
[0046] FIG. 42 is an enlarged view of a lip periphery of FIG.
41.
[0047] FIG. 43 is a perspective view of a potting portion of the
air flow meter in a configuration group G.
[0048] FIG. 44 is a vertical cross-sectional view of the air flow
meter attached to an intake pipe in a configuration group H.
[0049] FIG. 45 is a side view of the air flow meter as viewed from
the connector portion side.
[0050] FIG. 46 is a block diagram showing an electrical
configuration of a temperature correction unit.
[0051] FIG. 47 is a diagram illustrating processing in a first
correction unit.
[0052] FIG. 48 is a diagram showing a relationship between a flow
rate signal and a time constant.
[0053] FIG. 49 is a diagram showing temporal changes of a first
correction signal when a flow rate is large and when the flow rate
is small.
[0054] FIG. 50 is a diagram showing a temporal change of each of a
first temperature signal and the first correction signal.
[0055] FIG. 51 is a diagram showing a temporal change of each of
the first temperature signal and the second temperature signal.
[0056] FIG. 52 is a diagram showing a temporal change of each of a
temperature differential signal and a differential correction
signal.
[0057] FIG. 53 is a diagram showing a relationship between the
temperature differential signal and the differential correction
signal.
[0058] FIG. 54 is a diagram showing temporal changes of the first
temperature signal, the second temperature signal, and the first
correction signal in a configuration different from that of the
first embodiment.
[0059] FIG. 55 is a diagram showing a temporal change of each of
the temperature differential signal and the differential correction
signal in a configuration different from that of the first
embodiment.
[0060] FIG. 56 is a diagram showing a temporal change of each of
the first temperature signal, the first correction signal, and a
correction value signal.
[0061] FIG. 57 is a diagram showing a temporal change of each of
the first temperature signal, the first correction signal, the
correction value signal, and an actual temperature.
[0062] FIG. 58 is a horizontal cross-sectional view of the housing
around a detection throttle portion according to a second
embodiment.
[0063] FIG. 59 is a horizontal cross-sectional view of the housing
around a longitudinal partition wall.
[0064] FIG. 60 is a horizontal cross-sectional view of an air flow
meter around a housing protrusion according to a third
embodiment.
[0065] FIG. 61 is a side view of an air flow meter in a state of
being attached to an intake pipe according to a fourth
embodiment.
[0066] FIG. 62 is a front view of the air flow meter.
[0067] FIG. 63 is a cross-sectional view taken along a line
LXIII-LXIII line of FIG. 61.
[0068] FIG. 64 is a view showing an internal structure of the
housing in a state where the potting portion and the cover member
are removed.
[0069] FIG. 65 is a view showing a base member.
[0070] FIG. 66 is a view illustrating the attachment of a cover to
the base member.
[0071] FIG. 67 is a view illustrating the attachment of a sensor SA
to a housing body.
[0072] FIG. 68 is a view illustrating the formation of the potting
portion in the housing.
[0073] FIG. 69 is a perspective view of a first regulation portion
in a configuration group C.
[0074] FIG. 70 is an enlarged view of the periphery of a flow rate
detector in FIG. 63.
[0075] FIG. 71 is a cross-sectional view taken along a line
LXXI-LXXI of FIG. 70.
[0076] FIG. 72 is a vertical cross-sectional view of an air flow
meter in configuration groups E and F.
[0077] FIG. 73 is a front view of an air flow meter in a
configuration group G.
[0078] FIG. 74 is a vertical cross-sectional view of the housing
around a passage flow channel in a configuration group D according
to a fifth embodiment.
[0079] FIG. 75 is a cross-sectional view taken along a line
LXXV-LXXV of FIG. 74.
[0080] FIG. 76 is a diagram illustrating the molding of the passage
flow channel by the measurement molding portion and the passage
mold portion.
[0081] FIG. 77 is a cross-sectional view taken along a line
LXXVII-LXXVII of FIG. 76.
[0082] FIG. 78 is a view showing a state in which a measurement
molding portion is removed from the housing prior to the passage
mold portion.
[0083] FIG. 79 is a view showing a state in which the passage mold
portion is removed from the housing after the measurement molding
portion.
[0084] FIG. 80 is a vertical cross-sectional view of a housing in a
configuration group E according to a sixth embodiment.
[0085] FIG. 81 is a view illustrating the attachment of the sensor
SA to the housing.
[0086] FIG. 82 is a side view of an air flow meter in a state of
being attached to an intake pipe in Modification B1.
[0087] FIG. 83 is a cross-sectional view taken along a line
LXXXIII-LXXXIII line of FIG. 82.
[0088] FIG. 84 is a horizontal cross-sectional view of a housing in
Modification B3.
[0089] FIG. 85 is a horizontal cross-sectional view of the housing
in Modifications B2 and B3.
[0090] FIG. 86 is a horizontal cross-sectional view of the housing
in Modification B3.
[0091] FIG. 87 is a horizontal cross-sectional view of a housing in
Modification B4.
[0092] FIG. 88 is a vertical cross-sectional view of an air flow
meter in a state of being attached to an intake pipe in
Modification B5.
[0093] FIG. 89 is a vertical cross-sectional view of a periphery of
a sensor SA in Modification C1.
[0094] FIG. 90 is a vertical cross-sectional view of the periphery
of the sensor SA in Modification C2.
[0095] FIG. 91 is a perspective view of a positioning member.
[0096] FIG. 92 is a view showing an internal structure of a housing
in a state in which a potting portion and a cover member are
removed in Modification C3.
[0097] FIG. 93 is a diagram illustrating the molding of a passage
flow channel by a measurement molding portion, an inflow passage
mold portion, and an outflow passage mold portion in Modification
D1.
[0098] FIG. 94 is a view showing a state in which the measurement
molding portion, the inflow passage mold portion, and the outflow
passage mold portion are removed from the housing.
[0099] FIG. 95 is a diagram illustrating the molding of the passage
flow channel by the measurement molding portion and the passage
mold portion in Modification D2.
[0100] FIG. 96 is a vertical cross-sectional view of the housing
around the passage flow channel in Modification D4.
[0101] FIG. 97 is a vertical cross-sectional view of a housing in
Modifications E1 and E2.
[0102] FIG. 98 is a vertical cross-sectional view of the housing in
Modifications E1 to E3.
[0103] FIG. 99 is a vertical cross-sectional view of the housing in
Modifications E2 and E3.
[0104] FIG. 100 is a view showing an internal structure of the
housing in a state in which the potting portion and the cover
member are removed in Modification E4.
[0105] FIG. 101 is a vertical cross-sectional view of the housing
in which the base member and the sensor SA are disassembled.
[0106] FIG. 102 is a vertical cross-sectional view of a housing in
which a base member and a cover unit are disassembled in
Modification E5.
[0107] FIG. 103 is a vertical cross-sectional view of the housing
in Modification E6.
[0108] FIG. 104 is a side view of the housing.
[0109] FIG. 105 is a vertical cross-sectional view of the
housing.
[0110] FIG. 106 is a vertical cross-sectional view of the housing
in Modification F1.
[0111] FIG. 107 is a vertical cross-sectional view of the
housing.
[0112] FIG. 108 is an enlarged view of the periphery of a lip
periphery in Modification F2.
[0113] FIG. 109 is an enlarged view of the periphery of the lip in
Modification F3.
[0114] FIG. 110 is an enlarged view of the periphery of the
lip.
[0115] FIG. 111 is an enlarged view of the periphery of the lip in
Modification F4.
[0116] FIG. 112 is an enlarged view of the periphery of a lip in
Modification F5.
[0117] FIG. 113 is an enlarged view of the periphery of the
lip.
[0118] FIG. 114 is a vertical cross-sectional view of an air flow
meter in a state of being attached to an intake pipe in
Modification H1.
[0119] FIG. 115 is a block diagram showing an electrical
configuration of a temperature correction unit in Modification
H2.
[0120] FIG. 116 is a block diagram showing an electrical
configuration of a temperature correction unit in Modification
H3.
[0121] FIG. 117 is a block diagram showing an electrical
configuration of a temperature correction unit in Modification
H4.
[0122] FIG. 118 is a block diagram showing an electrical
configuration of a temperature correction unit in Modifications H5
and H7.
[0123] FIG. 119 is a block diagram showing an electrical
configuration of a temperature correction unit in Modifications H6
and H7.
[0124] FIG. 120 is a horizontal cross-sectional view of a housing
in Modification B4.
[0125] FIG. 121 is an enlarged view of a periphery of a lip in
Modification F6.
DETAILED DESCRIPTION
[0126] According to a first aspect of the present disclosure, a
physical quantity measurement device measures a physical quantity
of a fluid. The physical quantity measurement device includes a
measurement flow channel through which the fluid as a measurement
target flows, and a housing that forms the measurement flow channel
and is attached to a predetermined attaching target in a state
where at least a part of the housing is positioned inward of the
attaching target. The physical quantity measurement device includes
a physical quantity detector that detects a physical quantity of
the fluid in the measurement flow channel, and a same kind-quantity
detector that detects, in an interior of the housing, a physical
quantity of the same kind as the physical quantity detected by the
physical quantity detector. The physical quantity detected by the
same kind-quantity detector is a correction parameter used for
correcting a detection result of the physical quantity detector.
The physical quantity measurement device includes an inward part
that is positioned inward of the attaching target, and an outward
part that is positioned outward of the attaching target without
being positioned inward of the attaching target. The physical
quantity detector is provided at a position included in the inward
part. The same kind-quantity detector is provided at a position
closer to the outward part than the physical quantity detector is
in an alignment direction along which the inward part and the
outward part are aligned.
[0127] Heat may transfers from an external heat source, such as an
internal combustion engine or the like existing around the
attaching target, to the outward part of the housing. If the heat
is applied to the physical quantity detector through the housing,
an error between the detection result of the physical quantity
detector and the actual physical quantity may become large. In
other words, an accuracy in measurement of the physical quantity
may decrease.
[0128] On the other hand, according to the first aspect, since the
same kind-quantity detector is provided at a position closer to the
external heat source than the physical quantity detector is, a
degree of heat application indicating a degree of heat applied from
the external heat source is likely to be different between the same
kind-quantity detector and the physical quantity detector. In
addition, since the detection result of the same kind-quantity
detector is used as a correction parameter to correct the detection
result of the physical quantity detector, the measured value of the
physical quantity can be acquired. In this case, by using the fact
that the difference in degree of heat application is easily
reflected in the difference between the detection result of the
same kind-quantity detector and the detection result of the
physical quantity detector, an error between the measured value of
the physical quantity and the actual physical quantity can be
reduced. Therefore, the measurement accuracy of the physical
quantity can be enhanced.
[0129] According to a second aspect of the present disclosure, a
measurement control device controls a physical quantity measurement
device. The physical quantity measurement device includes a
measurement flow channel through which a fluid as a measurement
target flows, and a housing that forms the measurement flow channel
and is attached to a predetermined attaching target in a state
where at least a part of the housing is positioned inward of a
predetermined attaching target. The physical quantity measurement
device includes a physical quantity detector that detects a
physical quantity of the fluid in the measurement flow channel, and
a same kind-quantity detector that detects, in an interior of the
housing, a physical quantity of the same kind as the physical
quantity detected by the physical quantity detector. The physical
quantity measurement device includes an inward part that is
positioned inward of the attaching target, and an outward part that
is positioned outward of the attaching target without being
positioned inward of the attaching target. The physical quantity
detector is provided at a position included in the inward part. The
same kind-quantity detector is provided at a position closer to the
outward part than the physical quantity detector is in an alignment
direction along which the inward part and the outward part are
aligned. The measurement control device further comprises a
physical quantity correction unit that corrects a detection result
of the physical quantity detector based on a detection result of
the same kind-quantity detector.
[0130] According to the second aspect, since the detection result
of the physical quantity detector is corrected based on the
correction result of the same kind-quantity detector, an accuracy
in measurement of the physical quantity can be enhanced similarly
to the first embodiment.
[0131] According to a third aspect of the present disclosure, a
measurement control device controls a physical quantity measurement
device. The physical quantity measurement device includes a
measurement flow channel through which a fluid as a measurement
target flows, a housing that forms the measurement flow channel and
is attached to a predetermined attaching target, and a physical
quantity detector that detects a physical quantity of the fluid in
the measurement flow channel. The measurement control device
includes a change correction unit that corrects a detection result
of the physical quantity detector based on a behavior of change of
the detection result of the physical quantity detector.
[0132] Heat may transfer to the housing from the external heat
source, such as an internal combustion engine existing around the
attaching target. If the heat is applied to the physical quantity
detector through the housing, a delay may occur until the detection
result of the physical quantity detector indicates a result
corresponding to an actual physical quantity. In other words, the
response delay of the measurement of the physical quantity may
occur, as a result of which, an accuracy in measurement of the
physical quantity may be lowered.
[0133] On the other hand, according to the third aspect, since the
behavior of change of the detection result of the physical quantity
detector is used for the correction by the change correction unit,
the change correction unit predicts the behavior of change of the
detection result. Thus, a time required for the correction result
of the change correction unit to reach the result corresponding to
the actual physical quantity can be reduced as compared with a time
required for the detection result of the physical quantity detector
to reach the result corresponding to the actual physical quantity.
Therefore, the response delay of the physical quantity measurement
can be reduced, and as a result, an accuracy in measurement of the
physical quantity can be enhanced.
[0134] Hereinafter, multiple embodiments for implementing the
present disclosure will be described referring to drawings. In the
respective embodiments, a part that corresponds to a matter
described in a preceding embodiment may be assigned the same
reference numeral, and redundant explanation for the part may be
omitted. When only a part of a configuration is described in an
embodiment, another preceding embodiment may be applied to the
other parts of the configuration. The parts may be combined even if
it is not explicitly described that the parts can be combined. The
embodiments may be partially combined even if it is not explicitly
described that the embodiments can be combined, provided there is
no harm in the combination.
First Embodiment
[0135] A combustion system 10 shown in FIG. 1 includes an internal
combustion engine 11 such as a gasoline engine, an intake passage
12, an exhaust passage 13, an air flow meter 14, and an ECU 20, and
the combustion system 10 is mounted on a vehicle, for example. The
air flow meter 14 is provided in the intake passage 12, and has a
function of measuring physical quantities such as a flow rate, a
temperature, a humidity, and a pressure of an intake air supplied
to the internal combustion engine 11. The air flow meter 14
corresponds to a physical quantity measurement device for measuring
the intake air as a fluid. The intake air is a gas supplied to a
combustion chamber 11a of the internal combustion engine 11. In the
combustion chamber 11a, a mixture of the intake air and a fuel is
ignited by an ignition plug 17.
[0136] The ECU (Engine Control Unit) 20 is a control device for
controlling the operation of the combustion system 10. The ECU 20
is a calculation processing circuit including a processor, a
storage medium such as a RAM, a ROM and a flash memory, a
microcomputer including an input and output unit, a power supply
circuit, and the like. The ECU 20 receives a sensor signal output
from the air flow meter 14, sensor signals output from a large
number of vehicle-mounted sensors, and the like. The ECU 20
performs an engine control on a fuel injection amount, an EGR
amount, and the like of an injector 16 with the use of the
measurement result by the air flow meter 14. The ECU 20 is a
control device for controlling the operation of the internal
combustion engine 11, and the combustion system 10 may be referred
to as an engine control system. The ECU 20 corresponds to an
external device.
[0137] The air flow meter 14 is one of a large number of
measurement units included in the combustion system 10. In an
intake system and an exhaust system of the internal combustion
engine 11, for example, an air-fuel ratio sensor 18 and the like
are provided in addition to the air flow meter 14 as a measurement
unit. The air flow meter 14 is disposed on a downstream side of an
air cleaner 19 and an upstream side of a throttle valve 15 in the
intake passage 12. In that case, with respect to the air flow meter
14 in the intake passage 12, the air cleaner 19 side is on the
upstream side, and the combustion chamber 11a side is on the
downstream side.
[0138] The air flow meter 14 shown in FIGS. 2 and 3 is detachably
attached to an intake pipe 12a defining the intake passage 12. The
air flow meter 14 is inserted into an airflow insertion hole 12b
provided so as to penetrate through a cylindrical wall of the
intake pipe 12a, and at least a part of the air flow meter 14 is
located in the intake passage 12. The intake pipe 12a has a pipe
flange 12c extending from the airflow insertion hole 12b toward an
outer peripheral side, and includes a pipe made of a synthetic
resin material or the like. A pipe flange 12c extends along a
peripheral portion of the airflow insertion hole 12b, and is formed
in an annular shape, for example. A tip end face of the pipe flange
12c extends in a direction orthogonal to a center line of the pipe
flange 12c. In that case, the tip end face of the pipe flange 12c
extends in a longitudinal direction of the intake passage 12, that
is, in a direction in which the intake air flows in the intake
passage 12. The intake pipe 12a corresponds to an attaching
target.
[0139] The air flow meter 14 includes a housing 21, a flow rate
detector 22 (refer to FIG. 8), and an intake air temperature sensor
23. The housing 21 is made of, for example, a resin material or the
like. In the air flow meter 14, since the housing 21 is attached to
the intake pipe 12a, the flow rate detector 22 is brought into
contact with the intake air flowing through the intake passage 12.
The housing 21 includes a housing body 24, a ring holding portion
25, a flange portion 27, a connector portion 28, a root portion
29a, and a protective protrusion 29b, and an O-ring 26 is attached
to the ring holding portion 25. The housing body 24, the ring
holding portion 25, the flange portion 27, the connector portion
28, the root portion 29a, and the protective protrusion 29b are
manufactured by a single resin molding process, which will be
described later, in order to realize cost reduction.
[0140] As shown in FIGS. 2 to 7, the housing body 24 is formed in a
cylindrical shape as a whole, and in the housing 21, the ring
holding portion 25, the flange portion 27, the connector portion
28, the root portion 29a, and the protective protrusion 29b are
integrally provided in the housing body 24. When a width direction
X, a height direction Y, and a depth direction Z are defined in the
air flow meter 14, the housing body 24 extends in the height
direction Y, and the ring holding portion 25 and the flange portion
27 extend from the housing body 24 in the width direction X and the
depth direction Z. The ring holding portion 25, the flange portion
27, and the connector portion 28 are disposed on a base end side of
the housing 21 with respect to the housing body 24. Hereinafter,
the base end side of the housing 21 is also referred to as a
housing base end side, and a tip side of the housing 21 is also
referred to as a housing tip side. In other words, in the height
direction Y, a housing base end face 192 (shown in the drawing)
side, which will be described later, is referred to as the housing
base end side, and a housing tip end face 191 side is referred to
as a housing tip side. The housing base end face 192 may be
referred to as a base end or a base end portion of the housing 21,
and the housing tip end face 191 may be referred to as a tip or a
tip portion of the housing 21. The width direction X, the height
direction Y, and the depth direction Z are orthogonal to each
other.
[0141] The ring holding portion 25 is a portion that is fitted into
the airflow insertion hole 12b through the O-ring 26. The ring
holding portion 25 has a holding groove 25a circumferentially
extending along the periphery of the housing body 24, and holds the
O-ring 26 in a state in which the O-ring 26 is inserted into the
holding groove 25a. The ring holding portion 25 has a pair of
groove defining portions protruding in the width direction X and
the depth direction Z, and the groove defining portions are spaced
apart from each other in the height direction Y, so that the
holding groove 25a is defined between the groove defining portions.
The pair of groove defining portions may also be referred to as
seal guide walls.
[0142] The O-ring 26 is a member for sealing the intake passage 12
and the outside of the intake pipe 12a. The O-ring 26 is fitted
externally to the ring holding portion 25, and is interposed
between the ring holding portion 25 and the airflow insertion hole
12b in a state of entering an inner peripheral side of the pipe
flange 12c.
[0143] The flange portion 27 is disposed closer to the housing base
end side than the ring holding portion 25, and covers the airflow
insertion hole 12b from the outer peripheral side of the intake
pipe 12a. Further, the flange portion 27 can restrict the housing
21 from excessively entering the intake passage 12 by being caught
by the tip portion of the pipe flange 12c of the intake pipe 12a.
The connector portion 28 surrounds multiple connector terminals 28a
(refer to FIG. 6), and corresponds to a terminal protection portion
for protecting the connector terminals 28a. A plug portion is
inserted into the connector portion 28. The plug portion is
provided at an end portion of a connecting line which are
electrically connected directly or indirectly to the ECU 20 and
mates with the connector portion 28.
[0144] The housing 21 is formed with multiple thinned portions 41
for improving a dimensional accuracy and reducing a weight after
molding. The thinned portions 41 are provided, for example, on the
flange portion 27, the housing body 24, and the ring holding
portion 25. In addition, when the housing 21 is molded with resin,
a thickness of the housing 21 is appropriately thinned by the
thinned portions 41, so that a portion in which a molten resin does
not flow is hardly generated in the mold portion such as a mold.
Further, the deterioration of dimensional accuracy that occurs due
to cooling and shrinkage of the resin component after molding can
be inhibited. Multiple screw holes 42 are provided in the flange
portion 27, and the housing 21 is fixed to the intake pipe 12a with
the use of the screw holes 42. The intake pipe 12a is provided with
bosses 12d to which screw members (not shown) passing through the
screw holes 42 are mounted, and the flange portion 27 is supported
by the bosses 12d. Each of the bosses 12d extends along the pipe
flange 12c from the outer peripheral surface of the intake pipe
12a, and is disposed at a position separated from the pipe flange
12c. The bosses 12d may be provided integrally with the pipe flange
12c.
[0145] The root portion 29a protrudes from the ring holding portion
25 toward the housing tip side in the height direction Y, and is
disposed at a position laterally separated from the housing body 24
in the width direction X in order to avoid the influence of a heat
of the housing body 24 which has received the heat from the engine
and has risen in temperature. The intake air temperature sensor 23
includes a temperature sensing element 23a for sensing the
temperature of the intake air, a pair of lead wires 23b extending
from the temperature sensing element 23a, and a pair of intake air
temperature terminals 23c connected to the lead wires 23b. The pair
of intake air temperature terminals 23c extend from the root
portion 29a, and the temperature sensing element 23a is put across
the pair of intake air temperature terminals 23c through the pair
of lead wires 23b. Both the lead wires 23b and the intake air
temperature terminals 23c have conductivity, and the intake air
temperature terminals 23c are electrically connected to the
connector terminals 28a (refer to FIG. 18) provided in the
connector portion 28. The intake air temperature terminals 23c may
be connected to a bridge terminal 86 to be described later.
Although not shown in the drawing, in another embodiment, the lead
wires 23b and the intake air temperature terminals 23c may be
integrated together. The intake air temperature sensor 23 outputs a
detection signal corresponding to the intake air temperature sensed
by the temperature sensing element 23a.
[0146] The protective protrusion 29b protrudes laterally from the
housing body 24 in the width direction X, and is disposed closer to
the housing tip side than the intake air temperature sensor 23. A
protrusion dimension of the protective protrusion 29b from the
housing body 24 is larger than a separation distance of the intake
air temperature sensor 23 from the housing body 24. In that case,
when the housing 21 is viewed from the tip side, the intake air
temperature sensor 23 is seen to overlap with a back side of the
protective protrusion 29b. For that reason, when the housing 21 is
inserted into the airflow insertion hole 12b when the air flow
meter 14 is attached to the intake pipe 12a, even if the insertion
position of the housing 21 is deviated in the width direction X,
the protective protrusion 29b comes into contact with the outer
peripheral surface of the intake pipe 12a. Therefore, the intake
air temperature sensor 23 is restrained from being damaged by the
intake air temperature sensor 23 coming into contact with the outer
peripheral surface of the intake pipe 12a.
[0147] As shown in FIG. 8, the housing body 24 defines a bypass
flow channel 30 through which a part of the intake air flowing
through the intake passage 12 flows. The bypass flow channel 30 has
a passage flow channel 31 and a measurement flow channel 32, and
the passage flow channel 31 and the measurement flow channel 32 are
defined by an internal space of the housing body 24. The passage
flow channel 31 penetrates through the housing body 24 in the depth
direction Z, and includes an inflow port 33a as an upstream end
portion and an outflow port 33b as a downstream end portion. The
measurement flow channel 32 is a branch flow channel branched from
an intermediate portion of the passage flow channel 31, and has a
measurement outlet 33c which is a downstream end portion. The
intake passage 12 may be referred to as a main passage, and the
bypass flow channel 30 may be referred to as a sub-passage. In FIG.
8, the O-ring 26 is not shown.
[0148] Returning to the description of FIGS. 2 to 7, in the housing
body 24, the inflow port 33a is provided on an upstream-side end
face of the housing body 24, and the outflow port 33b is provided
on a downstream-side end face of the housing body 24. Further, one
measurement outlet 33c is provided on each of both side surfaces of
the housing body 24. The measurement outlets 33c have an elongated
shape extending in the height direction Y, and are aligned side by
side in the width direction X. A side surface of the housing body
24 has a flat surface 44 extending straight in the height direction
Y and the depth direction Z, and an upstream-side end face of the
housing body 24 has a curved surface 45 curved so as to bulge
toward the upstream side. The flat surface 44 and the curved
surface 45 are adjacent to each other in the depth direction Z, and
the measurement outlets 33c are disposed at a position across a
boundary between the flat surface 44 and the curved surface 45 in
the depth direction Z on the side surface of the housing body
24.
[0149] In this example, unlike the present embodiment, in the
configuration in which all of the measurement outlets 33c are
opened to the curved surface 45 of the upstream-side end face, the
measurement outlets 33c are susceptible to the dynamic pressure on
the upstream side of the intake passage 12. As a result, there is a
concern that a flow rate flowing into the measurement flow channel
32 from the passage flow channel 31 is unintentionally reduced, and
foreign matter such as dust enters the measurement flow channel 32
from the measurement outlet 33c.
[0150] Further, at the boundary between the flat surface 44 and the
curved surface 45 in the housing body 24, the intake air is likely
to be separated because a direction of advancement of the intake
air flowing along the flat surface 44 at the upstream-side end
portion changes at the flat surface 44. For that reason, unlike the
present embodiment, in the configuration in which all of the
measurement outlets 33c are opened to the flat surface 44 of the
side surface, the measurement outlet 33c is affected by the
separation of the intake air generated at the boundary between the
flat surface 44 and the curved surface 45, and there is a concern
that a flow velocity in the measurement flow channel 32 becomes
unstable.
[0151] In contrast to the above configurations, in the
configuration in which the measurement outlet 33c is disposed
across the flat surface 44 and the curved surface 45 as in the
present embodiment, there is an advantage that the measurement
outlet 33c is less susceptible to the effect of a dynamic pressure
on the upstream side of the intake passage 12 and the separation of
the intake air. In that case, the measurement outlet 33c is
disposed at a position in which the influence of the dynamic
pressure received from the upstream side of the intake passage 12
and the influence of the separation of a gas flowing through the
intake passage 12 are balanced with each other. Further, the
above-mentioned advantage is further increased by shortening the
measurement outlet 33c as much as possible in the depth direction
Z, and from the viewpoint of increasing the advantage, it is
preferable that the measurement outlet 33c has an elongated shape
in the height direction Y as in the present embodiment.
[0152] As shown in FIGS. 8 and 9, the passage flow channel 31 has
an inflow passage 31a extending straight from the inflow port 33a
and an outflow passage 31b extending straight from the outflow port
33b. The inflow passage 31a extends in the depth direction Z, while
the outflow passage 31b extends in a direction inclined with
respect to the depth direction Z. The outflow passage 31b is
inclined toward the outflow port 33b to the housing base end side,
with the result that the outflow port 33b is disposed at a position
deviated from the inflow port 33a toward the housing base end
side.
[0153] The passage flow channel 31 is configured to be narrowed
toward the outflow port 33b. In other words, the passage flow
channel 31 is configured not to be narrowed even when approaching
the inflow port 33a from the outflow port 33b in the depth
direction Z. The flow channel area of the inflow passage 31a is
uniform in the depth direction Z. In the inflow passage 31a, both
the height dimension in the height direction Y and the width
dimension in the width direction X are uniform in the depth
direction. On the other hand, a cross-sectional area of the outflow
passage 31b gradually decreases toward the outflow port 33b. In the
outflow passage 31b, the height dimension is uniform in the depth
direction Z, while the width dimension gradually decreases toward
the outflow port 33b.
[0154] A flow channel area of the passage flow channel 31 is a
cross-sectional area of the passage flow channel 31 in a direction
orthogonal to a center line of the passage flow channel 31 or a
direction in which the passage flow channel 31 extends. The center
line of the inflow passage 31a extends in the depth direction Z,
and the center line of the outflow passage 31b is slightly inclined
with respect to the depth direction Z.
[0155] As shown in FIGS. 4 to 7, the housing body 24 has a passage
throttle portion 47 for throttling the width dimension of the
outflow passage 31b, and a throttle configuration of the passage
flow channel 31 is realized by the passage throttle portion 47. The
housing body 24 has a constriction portion 48 that gradually
constricts the side surface and the downstream-side end face of the
housing body 24 toward the passage throttle portion 47. With the
provision of the constriction portion 48, an inner wall surface of
the passage throttle portion 47 and an inner wall surface of an
introduction path 32b can be connected to each other without a
step. As a result, a separation flow at the connection portion
between the outflow passage 31b and the introduction path 32b can
be inhibited from occurring, and the measurement accuracy is
improved.
[0156] Returning to the description of FIGS. 8 and 9, a flow
channel boundary portion 34, which is a boundary between the
passage flow channel 31 and the measurement flow channel 32, is a
boundary between the outflow passage 31b and the measurement flow
channel 32. The flow channel boundary portion 34 includes a
measurement inlet which is an upstream end portion of the
measurement flow channel 32. In the depth direction Z, a length
dimension of the flow channel boundary portion 34 is the same as
the length dimension of the outflow passage 31b. In that case, the
flow channel boundary portion 34 is not exposed from the inflow
port 33a in the depth direction Z because the inflow port 33a side
of the flow channel boundary portion 34 is disposed closer to the
housing tip side. In this example, in the inner peripheral surface
of the passage flow channel 31, a surface of the housing base end
side is referred to as a ceiling surface, and a surface of the tip
side is referred to as a bottom surface. In that case, when the
outflow port 33b is viewed from the upstream side in the depth
direction Z, the flow channel boundary portion 34 is hidden on a
back side of a ceiling surface of the inflow passage 31a so as to
be invisible. As a result, even if foreign matter such as dust,
dust, waterdrops, or oil drops fly off along with the intake air,
the foreign matter travels straight through the passage flow
channel 31 and is discharged from the outflow port 33b, so that the
foreign matter can be prevented from breaking the detection element
22b without reaching the flow rate detector 22, and the foreign
matter can be prevented from accumulating to deteriorate the
detection accuracy.
[0157] The measurement flow channel 32 has a folded shape folded
back at an intermediate position. The measurement flow channel 32
includes a detection path 32a provided with the flow rate detector
22, an introduction path 32b for introducing the intake air into
the detection path 32a, and a discharge path 32c for discharging
the intake air from the detection path 32a. The introduction path
32b extends from the flow channel boundary portion 34 toward the
housing base end side, and the discharge path 32c extends from the
measurement outlet 33c toward the housing base end side. The
introduction path 32b and the discharge path 32c extend in parallel
with each other in the height direction Y, and the respective flow
channel areas of the introduction path 32b and the discharge path
32c are uniform in the height direction Y. In the introduction path
32b and the discharge path 32c, both the width dimension in the
width direction X and the depth dimension in the depth direction Z
are uniform in the height direction. In that case, the introduction
path 32b and the discharge path 32c are not narrowed even when
approaching the housing base end side.
[0158] The flow channel area of the measurement flow channel 32 is
a cross-sectional area of the measurement flow channel 32 in a
direction orthogonal to the center line of the measurement flow
channel 32. The center lines of the introduction path 32b and the
discharge path 32c extend in the height direction Y, and the center
line of the detection path 32a extends in the depth direction Z.
The height direction Y in which the introduction path 32b and the
discharge path 32c extend corresponds to a direction in which the
detection path 32a and the housing opening 61 are aligned and the
direction in which the measurement flow channel 32 and the sensor
SA 50 are aligned.
[0159] The detection path 32a is disposed closer to the housing
base end side than the introduction path 32b and the discharge path
32c, and connects the downstream end portion of the introduction
path 32b and the upstream end portion of the discharge path 32c
with each other in a state where the detection path 32a is extended
to the introduction path 32b and the discharge path 32c. The
introduction path 32b is disposed downstream of the discharge path
32c in the depth direction Z, and the intake air flows in the
detection path 32a in a direction opposite to the intake passage 12
and the passage flow channel 31. In the measurement flow channel
32, the intake air flowing in from the passage flow channel 31 once
flows toward the housing base end side, and then U-turns by passing
through the detection path 32a to flow toward the housing tip side.
With the provision of the U-turned shaped flow channel, even if
foreign matter such as dust, dust, waterdrops, or oil droplets fly
off together with the intake air, the foreign matter can be
prevented from damaging the detection element 22b without reaching
the flow rate detector 22, and the foreign matter can be prevented
from accumulating to deteriorate the detection accuracy. In the
first place, the foreign matter that has entered the passage flow
channel 31 from the inflow port 33a travels along the flow of the
intake air, so that the foreign matter is likely to be discharged
from the outflow port 33b, and hardly flows from the passage flow
channel 31 into the measurement flow channel 32. This also makes it
difficult for the foreign matter to reach the flow rate detector
22.
[0160] The measurement outlet 33c opens the discharge path 32c in
the width direction X. A sum total of the opening areas of the two
measurement outlets 33c is substantially the same as the flow
channel area of the discharge path 32c. For example, unlike the
present embodiment, in a configuration in which the sum total of
the opening areas of the two measurement outlets 33c is larger than
the flow channel area of the discharge path 32c, there is a concern
that foreign matter is likely to enter the discharge path 32c from
the measurement outlet 33c. In addition, in the configuration in
which the sum total opening area is smaller than the flow channel
area, the intake air flowing through the measurement flow channel
32 is less likely to flow out from the measurement outlet 33c, and
there is a concern that a flow velocity of the intake air passing
through the flow rate detector 22 is lowered and the detection
accuracy of the flow rate detector 22 is lowered. On the other
hand, according to the present embodiment, since the sum total
opening area is substantially the same as the flow channel area, an
entry of foreign matter from the measurement outlet 33c and a
decrease in the flow velocity in the measurement flow channel 32
can be inhibited.
[0161] The flow rate detector 22 includes a detection board 22a as
a circuit board, and a detection element 22b mounted on the
detection board 22a. The detection board 22a forms an outer contour
of the flow rate detector 22, and the detection element 22b is
disposed at the center of the board surface of the detection board
22a. In that case, the detection element 22b is disposed at the
center of the flow rate detector 22. The detection board 22a is
electrically connected to the connector terminals 28a (refer to
FIG. 18). The detection element 22b has a heat generation portion
such as a heat generating resistive element and a temperature
detector, and the flow rate detector 22 outputs a detection signal
according to a change in temperature caused by heat generation in
the detection element 22b. The flow rate detector 22 may also be
referred to as a sensor chip.
[0162] In this example, in order to properly maintain the detection
accuracy of the flow rate detector 22, there is a need to increase
a temperature change in the temperature detector attributable to
the intake flow rate in the detection element 22b to some extent,
and in order to increase the temperature change, it is preferable
to increase a flow velocity of a fluid coming in contact with the
detection element 22b to some extent. This is to eliminate the
influence of the temperature change acting on the detection element
22b by natural convection with respect to the temperature change of
the detection element 22b according to the flow velocity of the
fluid. The temperature change due to the natural convection depends
on an installation angle of the detection element 22b, and causes
an error in the detection signal of the temperature change due to
the fluid. With an increase in the flow velocity of the fluid
coming in contact with the detection element 22b, the influence of
natural convection caused by the installation angle of the
detection element 22b and the air flow meter 14 can be eliminated,
and the detection of the fluid can be properly maintained.
[0163] The flow rate detector 22 corresponds to a physical quantity
detector that detects the flow rate of the intake air as a physical
quantity. The flow rate detector 22 is not limited to a thermal
type flow rate sensor, and may be an ultrasonic type flow rate
sensor, a Kalman vortex type flow rate sensor, or the like.
[0164] The air flow meter 14 has a sensor sub-assembly including a
tip-type flow rate detector 22, and the sensor sub-assembly is
referred to as a sensor SA 50. In this instance, the sensor SA 50
may be referred to as a sensor unit, and the air flow meter 14 may
be referred to as a tip-type flow rate measurement device. The
sensor SA 50 corresponds to a detection unit.
[0165] As shown in FIG. 10, the sensor SA 50 includes a circuit
accommodation portion 51, a junction portion 52, a sensing portion
53, and lead terminals 54, and is formed in a plate shape extending
in the depth direction Z and the height direction Y as a whole. In
the height direction Y, the junction portion 52 is provided between
the circuit accommodation portion 51 and the sensing portion 53,
and the lead terminals 54 have conductivity and extend from the
circuit accommodation portion 51 toward the opposite side of the
sensing portion 53. In both the width direction X and the depth
direction Z, the junction portion 52 is thinner than the circuit
accommodation portion 51, and the sensing portion 53 is further
thinner than the junction portion 52. Specifically, in both the
width dimension in the width direction X and the depth dimension in
the depth direction Z, the junction portion 52 is smaller than the
circuit accommodation portion 51, and the sensing portion 53 is
further smaller than the junction portion 52. In that case, a
circuit step surface 55 is formed between the circuit accommodation
portion 51 and the junction portion 52, and a sensing step surface
56 is formed between the junction portion 52 and the sensing
portion 53. Each of the step surfaces 55 and 56 extends annularly
along a peripheral portion of the junction portion 52 so as to be
circumferentially arranged, and faces a tip side of the sensor SA
50.
[0166] The sensing portion 53 includes at least a part of the
detection board 22a and the detection element 22b in the flow rate
detector 22, and also includes a sensing support portion 57 for
supporting the included part in the sensing portion 53. The sensing
support portion 57 forms an outer contour of the sensing portion
53, and extends from the junction portion 52 toward the tip side of
the flow rate detector 22.
[0167] As shown in FIG. 8, FIG. 11, and FIG. 12, in the housing 21,
the sensor SA 50 is disposed at a position where the sensing
portion 53 enters the detection path 32a. The sensing portion 53 is
disposed at an intermediate position of the detection path 32a in
the width direction X, and extends in the depth direction Z and the
height direction Y. The sensing portion 53 is in a state in which
an intermediate region of the detection path 32a is partitioned in
the width direction X, and a detection throttle portion 59 for
throttling the detection path 32a by reducing the flow channel area
of the detection path 32a is provided at a position facing the flow
rate detector 22 on an inner peripheral surface of the detection
path 32a. The detection throttle portion 59 protrudes from the
inner peripheral surface of the detection path 32a toward the flow
rate detector 22, and a depth dimension D1 of the detection
throttle portion 59 in the depth direction Z is larger than a depth
dimension D2 of the flow rate detector 22 in the depth direction Z.
In a region where the flow rate detector 22 exists in the height
direction Y, a depth dimension D3 of the sensing support portion 57
in the depth direction Z is larger than a depth dimension D1 of the
detection throttle portion 59.
[0168] The detection throttle portion 59 has a tapered shape in the
width direction X. Specifically, a base end portion of the
detection throttle portion 59 protruding from the inner wall of the
housing body 24 in the width direction X is the widest portion, and
a tip portion of the detection throttle portion 59 is the narrowest
portion. The width dimension of the base end portion of the
detection throttle portion 59 is set to the depth dimension D1
described above. The detection throttle portion 59 has a curved
surface that expands toward the flow rate detector 22. The
detection throttle portion 59 may have a tapered shape expanded
toward the flow rate detector 22.
[0169] When a surface of the inner peripheral surface of the
detection path 32a on the housing tip side is referred to as a
bottom surface and a surface on the housing base end side is
referred to as a ceiling surface, the bottom surface of the
detection path 32a is formed by the housing body 24, while the
ceiling surface is formed by the sensing step surface 56 of the
sensor SA 50. In other words, the detection path 32a is partitioned
by the sensing step surface 56. In this example, in an open region
PB, the junction portion 52 is accommodated in an accommodation
region PB1 as a part of the sensor SA 50, and a boundary between
the accommodation region PB1 and a measurement region PB2 coincides
with the sensing step surface 56. When a gap exists between the
junction portion 52 and the housing body 24, the gap may
communicate with the detection path 32a.
[0170] The detection throttle portion 59 extends from the bottom
surface of the detection path 32a toward the ceiling surface. The
outer peripheral surface of the detection throttle portion 59
extends straight in the height direction Y. In the height direction
Y, the detection throttle portion 59 and the sensing step surface
56 of the sensor SA 50 are separated from each other, and a space
between the tip of the detection throttle portion 59 and the
sensing step surface 56 is also included in the detection path
32a.
[0171] In the detection path 32a, a separation distance between the
sensing support portion 57 and the detection throttle portion 59
gradually decreases toward the flow rate detector 22 in the depth
direction Z. In the above configuration, when the intake air
flowing into the detection path 32a from the introduction path 32b
passes between the sensing support portion 57 and the detection
throttle portion 59, the flow velocity of the intake air is likely
to increase toward the detection element 22b of the flow rate
detector 22. In that case, since the intake air is applied to the
detection element 22b at an appropriate flow velocity, the
detection accuracy of the flow rate detector 22 can be
enhanced.
[0172] Returning to the description of FIG. 8, the housing body 24
is formed in a cylindrical shape as a whole. The housing body 24
has a housing opening 61 that opens the internal space 24a, and the
housing opening 61 is formed in one end face of the housing body
24. The other end of the housing body 24 is closed, and the closed
part is referred to as a housing bottom portion 62, and the housing
bottom portion 62 forms a bottom surface of the passage flow
channel 31. The housing body 24 has holes that define the inflow
port 33a and the outflow port 33b, and those holes extend from the
housing bottom portion 62 toward the housing base end side.
[0173] The air flow meter 14 has a potting portion 65 as a closing
portion for closing the housing opening 61. The potting portion 65
seals the internal space 24a of the housing body 24 by filling the
internal space 24a with a resin material such as a molten potting
resin. In that case, the potting portion 65 may be referred to as a
sealing portion or a seal portion. The potting portion 65 is not
formed integrally with the housing 21 in the air flow meter 14, but
is formed independently of the housing 21.
[0174] The internal space 24a includes the sealing region PA sealed
by the potting portion 65 and the open region PB not sealed by the
potting portion 65. The sealing region PA extends from the housing
opening 61 toward the housing tip side, and the open region PB is
disposed on the housing tip side of the sealing region PA. The open
region PB extends from the sealing region PA toward the housing tip
side, and the open region PB includes the measurement flow channel
32. The boundary between the sealing region PA and the open region
PB extends in a direction orthogonal to the height direction Y. The
sealing region PA corresponds to a potting region.
[0175] The open region PB has an accommodation region PB1 in which
a part of the sensor SA 50 is accommodated, and a measurement
region PB2 in which the measurement flow channel 32 is provided.
The accommodation region PB1 extends from the sealing region PA
toward the housing tip side, and the measurement region PB2 is
provided on the housing tip side of the accommodation region PB1.
The boundary between the accommodation region PB1 and the
measurement region PB2 extends in a direction perpendicular to the
height direction Y, and the accommodation region PB1 and the
measurement region PB2 divide the open region PB into two in the
height direction Y.
[0176] A region step surface 66 is formed on the inner peripheral
surface of the housing body 24 between the inner peripheral surface
of the sealing region PA and the inner peripheral surface of the
open region PB. The region step surface 66 extends annularly so as
to surround the internal space 24a, and faces the housing base end
side. For the purpose of reducing a wall thickness of the housing
body 24 as much as possible, the housing body 24 is provided with
an overhanging portion 66a which overhangs to the outer peripheral
side in accordance with the region step surface 66. The region step
surface 66 and the overhanging portion 66a are disposed closer to
the housing tip side than the ring holding portion 25. The region
step surface 66 corresponds to a hooking portion.
[0177] A sealing step surface 67 provided closer to the housing
base end side than the region step surface 66 is provided on the
inner peripheral surface of the sealing region PA. Similar to the
region step surface 66, the sealing step surface 67 extends
annularly around the periphery of the sealing region PA so as to
face the housing base end side.
[0178] The sensor SA 50 extends over the sealing region PA and the
open region PB in the height direction Y, and is entirely
accommodated in the internal space 24a of the housing 21. The
circuit step surface 55 of the sensor SA 50 is caught by the region
step surface 66 of the housing 21, thereby restricting the sensor
SA 50 from further entering the internal space 24a. Further, the
circuit step surface 55 and the region step surface 66 abut against
each other in close contact with each other, and when the potting
portion 65 is formed, entering of the molten resin into the open
region PB is restricted by the abutment portion. In that instance,
the boundary between the sealing region PA and the open region PB
coincides with the boundary between the circuit accommodation
portion 51 and the junction portion 52 of the sensor SA 50. The
sensor SA 50 is assembled to the housing 21, so that all or part of
the internal space 24a of the housing 21 is occupied by the sensor
SA 50.
[0179] In the depth direction Z, a depth dimension D5 of the
sealing region PA at the region step surface 66 is larger than a
depth dimension D6 of the open region PB. In that instance, in the
sensor SA 50, a depth dimension D7 of the circuit accommodation
portion 51 at the circuit step surface 55 is smaller than the depth
dimension D5 of the sealing region PA and larger than the depth
dimension D6 of the open region PB. As shown in FIG. 11, a width
dimension W1 of the sealing region PA at the region step surface 66
in the width direction X is larger than a width dimension W2 of the
open region PB. In that instance, in the sensor SA 50, a width
dimension W3 of the circuit accommodation portion 51 at the circuit
step surface 55 is smaller than the width dimension W1 of the
sealing region PA and larger than the width dimension W2 of the
open region PB. In this manner, a configuration is realized in
which the circuit step surface 55 of the sensor SA 50 is caught by
the region step surface 66 of the housing 21.
[0180] In the sensor SA 50, the width direction X and the depth
direction Z are orthogonal to a direction in which the circuit
accommodation portion 51 and the flow rate detector 22 are aligned,
and orthogonal to a direction in which the sensing support portion
57 protrudes from the junction portion 52. The width direction X
and the depth direction Z are a direction orthogonal to the
direction in which the lead terminals 54 protrude from the circuit
accommodation portion 51. In the housing 21, the depth direction Z
is a direction in which the intake air flows in the passage flow
channel 31 and the detection path 32a.
[0181] The housing body 24 has a lateral partition wall 68 and a
longitudinal partition wall 69, and the partition walls 68 and 69
are provided in a lateral direction in the depth direction Z. The
lateral partition wall 68 divides the internal space 24a in a
direction orthogonal to the height direction Y, thereby defining an
end portion of the open region PB on the housing tip side. The
lateral partition wall 68 extends from the upstream-side outer
peripheral portion of the housing body 24 toward the downstream
side, and separates the open region PB and the inflow passage 31a
vertically. The lateral partition wall 68 is disposed closer to the
housing base end side than the inflow port 33a, and forms a ceiling
surface of the inflow passage 31a. The longitudinal partition wall
69 extends from the lateral partition wall 68 toward the housing
base end side, separates the introduction path 32b and the
discharge path 32c of the measurement flow channel 32 from each
other, and forms the floor surface of the detection path 32a. The
lateral partition wall 68 may be referred to as a lateral partition
portion, and the longitudinal partition wall 69 may be referred to
as a longitudinal partition portion. The lateral partition wall 68
corresponds to a passage partition portion, and the longitudinal
partition wall 69 corresponds to a measurement partition
portion.
[0182] The housing body 24 is configured not to narrow the internal
space 24a even when the housing body 24 approaches the housing
opening 61 from the housing base end side with respect to the
inflow port 33a and the outflow port 33b. In the above
configuration, even if the inner peripheral surface of the housing
body 24 has a step surface facing the housing base end side like
the region step surface 66, there is no step surface facing the
housing tip side. Further, a separation distance between portions
of the inner peripheral surface of the housing 21 facing each other
across the internal space 24a does not become small even if the
separation distance increases or does not change toward the housing
opening 61 in the height direction Y.
[0183] The longitudinal partition wall 69 is configured so as not
to become thick even when approaching the housing opening 61 in the
height direction Y. In the above configuration, a depth dimension
of the longitudinal partition wall 69 in the depth direction Z does
not increase even if the depth dimension decreases or does not
change toward the housing opening 61 in the height direction Y. In
FIGS. 12 and 13, the depth dimension D1 of the detection throttle
portion 59 is the same as or smaller than a depth dimension D8 of a
portion where the longitudinal partition wall 69 is thin in the
depth direction Z. As a result, a step surface facing the housing
tip side is not formed at the boundary between the detection
throttle portion 59 and the longitudinal partition wall 69.
[0184] Returning to the description of FIG. 8, the internal space
24a of the housing body 24 may be narrowed as the internal space
24a approaches the housing opening 61 in the region closer to the
housing tip side than the lateral partition wall 68 in the height
direction Y. In other words, the width dimension of the passage
flow channel 31 in the width direction X may gradually decrease as
the passage flow channel 31 approaches the housing opening 61 in
the height direction Y. In addition, a step surface facing the
housing tip side may be formed on the inner peripheral surface of
the passage flow channel 31.
[0185] However, as described above, the passage flow channel 31 is
configured not to be narrowed even when approaching the inflow port
33a in the depth direction Z. In the above configuration, the inner
peripheral surface of the passage flow channel 31 may have a step
surface facing the inflow port 33a side, but there is no step
surface facing the outflow port 33b side.
[0186] In the internal space 24a of the housing body 24, since the
junction portion 52 of the sensor SA 50 is fitted to the inner
peripheral surface of the housing body 24, the circuit step surface
55 of the sensor SA 50 and the region step surface 66 of the
housing body 24 are held in an abutment position. When one surface
of the plate surfaces of the sensor SA 50 on which the flow rate
detector 22 is provided is referred to as a front surface and the
other surface on the other side of the front surface is referred to
as a back surface, as shown in FIGS. 8 and 14, the sensor SA 50 has
a front SA protrusion 71a protruding to the front side and a back
SA protrusion 71b protruding to the back side. Two front SA
protrusions 71a and two back SA protrusions 71b are provided in
each of the junction portions 52.
[0187] The housing body 24 has a width housing protrusion 72a
protruding in the width direction X from an inner peripheral
surface of the housing body 24, and a depth housing protrusion 72b
protruding in the depth direction Z. The housing protrusions 72a
and 72b protrude from the inner peripheral surface of the housing
body 24 toward the inner peripheral side. Two width housing
protrusions 72a are provided at positions facing the front surface
of the sensor SA 50. One depth housing protrusion 72b is provided
at a position facing a side surface of the sensor SA 50 in the
upstream-side outer peripheral portion of the housing body 24, and
extends in a direction away from the curved surface 45 of the
housing body 24 in a direction inclined with respect to the depth
direction Z.
[0188] The housing protrusions 72a and 72b are disposed on the
inner peripheral surface of the open region PB, and thus are
provided closer to the housing tip side than the ring holding
portion 25. In this example, in the housing 21, the wall thickness
of the portion where the ring holding portion 25 is formed is
relatively large due to the provision of the ring holding portion
25 on the outer peripheral side of the housing body 24, the
provision of the holding groove 25a, and the like. For that reason,
in the case of molding the housing 21 with resin, there is a
concern that the resin distortion of the portion of the housing 21
where the ring holding portion 25 is formed is likely to occur as
the molten resin is cured. On the other hand, as described above,
since the housing protrusions 72a and 72b are disposed at positions
separated from the ring holding portion 25 toward the housing tip
side, the influence of the resin distortion in the ring holding
portion 25 is less likely to be applied to the housing protrusions
72a and 72b. For that reason, the dimensions and positions of the
housing protrusions 72a and 72b can be accurately realized as
designed.
[0189] The respective tip end faces of the front SA protrusion 71a
and the width housing protrusion 72a are in contact with each
other, and the back SA protrusion 71b is in contact with a flat
portion of the inner peripheral surface of the housing body 24. As
a result, the relative movement of the sensor SA 50 to the housing
body 24 in the width direction X is regulated. Further, in the
junction portion 52, the tip end face of the depth housing
protrusion 72b abuts on the side end face of the housing body 24 on
the side of the curved surface 45, and in the junction portion 52,
the side end face of the side opposite to the curved surface 45
abuts on the flat portion of the inner peripheral surface of the
housing body 24. As a result, the sensor SA 50 is restricted from
moving relative to the housing body 24 in the depth direction
Z.
[0190] The sensor SA 50 is disposed at a position closer to the
side of the inner peripheral surface of the housing body 24 facing
away from the width housing protrusion 72a than the center of the
internal space 24a in the width direction X because no protrusion
corresponding to the back SA protrusion 71b is provided on the
inner peripheral surface of the housing body 24. In other words,
the sensor SA 50 is disposed at a position closer to the back
surface of the sensor SA 50.
[0191] In this example, the housing protrusions 72a and 72b in
which the sensor SA 50 is not fitted to the inner peripheral
surface of the housing body 24 at the time of manufacturing the air
flow meter 14 will be described referring to FIGS. 15 and 16. As
shown in FIG. 15, the protrusion dimensions of the housing
protrusions 72a and 72b from the inner peripheral surface of the
housing body 24 are larger than those after the sensor SA 50 has
been fitted. For example, the housing protrusions 72a and 72b,
which are not fitted with the sensor SA 50, are tapered in the
protruding directions, and the housing protrusions 72a and 72b have
sharp tips.
[0192] The inner peripheral surface of the housing body 24 has a
protrusion support surface 73 for supporting the housing
protrusions 72a and 72b. In this example, in order to prevent the
end faces of the housing protrusions 72a and 72b from becoming step
surfaces facing the housing tip side, a protrusion covering surface
74 for covering the housing protrusions 72a and 72b from the
housing tip side is included in the inner peripheral surface of the
housing body 24. The protrusion covering surface 74 is provided
closer to the housing tip side than the protrusion support surface
73, and is disposed closer to the inner peripheral side in the
width direction X and the depth direction Z than the protrusion
support surface 73. A covering step surface 75 facing the housing
base end side is formed at a boundary between the protrusion
support surface 73 and the protrusion covering surface 74.
[0193] As shown in FIG. 14 and FIG. 16, unlike the housing
protrusions 72a and 72b, the SA protrusions 71a and 71b of the
sensor SA 50 have no significant change in shapes and dimensions
before and after the SA protrusions 71a and 71b are fitted to the
inner peripheral surface of the housing body 24. This is because
the SA protrusions 71a and 71b are made of a material having higher
hardness and strength than the housing protrusions 72a and 72b.
[0194] In FIGS. 15 and 16, in the housing body 24 prior to the
sensor SA 50 being fitted, an effective dimension W4 of the
internal space 24a in the width direction X excluding the SA
protrusions 71a and 71b is smaller than a width dimension W5 of the
thickest part of the sensor SA 50 in the width direction X. The
width dimension W5 is a separation distance between the tips of the
SA protrusions 71a and 71b. In that case, when the sensor SA 50 is
inserted into the internal space 24a from the housing opening 61,
the tip portion of the width housing protrusion 72a is scraped off
by the front SA protrusion 71a, and the tip portion of the depth
housing protrusion 72b is scraped off by the side end face of the
junction portion 52. In this instance, the sensor SA 50 is pressed
toward the back surface of the inner peripheral surface of the
housing body 24 and toward the side of the inner peripheral surface
of the housing body 24 facing away from the curved surface 45, so
that the sensor SA 50 is accurately positioned in the internal
space 24a in the width direction X. When the sensor SA 50 is
inserted into the internal space 24a, the deformation of the
housing protrusions 72a and 72b pressed by the front SA protrusion
71a and the junction portion 52 is more likely to occur than
scraping of the tip portions of the housing protrusions 72a and
72b. In that case, the housing protrusions 72a and 72b are deformed
so as to be crushed by the front SA protrusions 71a and the
junction portion 52, whereby the protrusion dimensions of the
housing protrusions 72a and 72b are reduced.
[0195] As described above, in the configuration in which the width
dimension W5 of the sensor SA 50 is defined by the SA protrusions
71a and 71b, the manufacturing variation of the width dimension W5
is less likely to occur as compared with the configuration in which
the width dimension W5 is defined by the front surface and the back
surface of the junction portion 52, for example. For that reason,
the positioning accuracy of the sensor SA 50 with respect to the
housing body 24 in the width direction X and the depth direction Z
can be further improved as compared with a configuration in which
the sensor SA 50 does not have the SA protrusions 71a and 71b.
[0196] Each of the SA protrusions 71a and 71b and the housing
protrusions 72a and 72b has an elongated shape extending in the
height direction Y. The SA protrusions 71a and 71b extend from the
circuit step surface 55 toward the housing tip side to an
intermediate position of the junction portion 52, and the housing
protrusions 72a and 72b extend from the region step surface 66
toward the housing tip side to an intermediate position of the
housing body 24. In the present embodiment, the housing protrusions
72a and 72b extend toward the housing tip side more than the SA
protrusions 71a and 71b, and the tip portion of the width housing
protrusion 72a remains at the housing tip side more than the front
SA protrusion 71a without being scraped off. When the width housing
protrusion 72a is deformed by being pressed by the front SA
protrusion 71a, a portion of the width housing protrusion 72a
located closer to the housing tip side than the front SA protrusion
71a is not deformed or slightly deformed.
[0197] The SA protrusions 71a and 71b may extend to the end portion
of the junction portion 52 on the housing tip side. The housing
protrusions 72a and 72b may extend to the end portion of the open
region PB on the housing tip side. In that case, since the end
faces of the housing protrusions 72a and 72b do not face the
housing base end side in the open region PB, there is no need to
provide the protrusion covering surface 74 and the covering step
surface 75.
[0198] FIGS. 12 and 13 are different from FIGS. 14 and 15 in the
cross-sectional shape of the internal space 24a of the housing body
24 because FIGS. 12 and 13 are schematic diagrams, and FIGS. 12 to
15 are diagrams relating to the air flow meter 14 of FIG. 8. In
FIG. 11, the SA protrusions 71a and 71b and the housing protrusions
72a and 72b are not shown, and in FIG. 14, the protrusion covering
surface 74 and the covering step surface 75 are not shown.
[0199] As shown in FIG. 17, the sensor SA 50 includes a circuit
chip 81 for performing various processes, a lead frame 82 for
supporting the circuit chip 81, a relay board 83, and bonding wires
84 in addition to the flow rate detector 22 and the lead terminals
54. The relay board 83 relays the signal from the flow rate
detector 22 to the circuit chip 81. The multiple bonding wires 84
are provided so that the detection board 22a and the lead terminals
54 are electrically connected to each other.
[0200] The sensor SA 50 also includes a mold portion 76 that forms
an outer contour of the sensor SA 50. The mold portion 76 is made
of a resin material such as a mold resin, and fixes the flow rate
detector 22, the lead terminals 54, the circuit chip 81, the lead
frame 82, the relay board 83, the bonding wires 84, and the like in
a protected state. The bonding wires 84 bridged between the relay
board 83 and the detection board 22a is protected by a protective
portion 77 made of a resin material such as a potting resin. The
detection board 22a is provided with a dam material 78 extending
along the peripheral portion of the protective portion 77, and the
dam material 78 serves to define the shape of the molten resin when
forming the protective portion 77.
[0201] The mold portion 76 has a support surface 76a for supporting
the detection board 22a. The plate surface of the detection board
22a is bonded to the support surface 76a in an overlapping state,
and the detection board 22a is supported in a state of being
sandwiched between the support surface 76a and the protective
portion 77. In this example, in the sensor SA 50, the support
surface 76a and the circuit chip 81 are disposed at positions as
far as possible apart from the circuit step surface 55 which is a
fixed part with the housing body 24. For example, the support
surface 76a and the circuit chip 81 are not disposed at positions
that extend laterally to the circuit step surface 55 in the width
direction X and the height direction Y. In this instance, even if
the sensor SA 50 is deformed by an external force applied to the
circuit step surface 55, the flow rate detector 22 and the circuit
chip 81 are less likely to be deformed, and therefore, the
operation accuracy of the circuit chip 50 can be appropriately
maintained.
[0202] As shown in FIGS. 18 and 19, the lead terminals 54 of the
sensor SA 50 are electrically connected to the connector terminals
28a of the connector portion 28 through the terminal unit 85 in the
sealing region PA of the housing body 24. The multiple lead
terminals 54 and the multiple connector terminals 28a are aligned
at predetermined intervals in the depth direction Z. The lead
terminal 54 and the connector terminal 28a corresponding to each
other are disposed as a pair of terminals at positions facing each
other in the width direction X, and those terminals 28a and 54 are
connected to each other through the terminal unit 85.
[0203] As shown in FIG. 20, the terminal unit 85 includes multiple
bridge terminals 86 and a terminal fixing portion 87 for fixing the
bridge terminals 86. Each of the bridge terminals 86 is an
elongated member having conductivity and extending generally in a
U-shape. The bridge terminal 86 has a first connection portion 86a
to which the connector terminal 28a is connected, and a second
connection portion 86b to which the lead terminal 54 is connected.
The connection portions 86a and 86b are portions in which parts of
the bridge terminals 86 protrude while being curved in the
thickness direction, and the protruding portions are connected to
the terminals 28a and 54 by welding or the like. The multiple
bridge terminals 86 are aligned at predetermined intervals in the
depth direction Z, and the terminal fixing portion 87 connects
intermediate portions of the bridge terminals 86 to each other in a
state of extending in the depth direction Z. The terminal fixing
portion 87 is formed of a resin material or the like having
electrical insulating properties.
[0204] The connector terminals 28a, the lead terminals 54, and the
bridge terminals 86 are connected to each other and extend in the
height direction Y. In that case, since there is no need to perform
a bending process such as a post-bending process in accordance with
an actual positional relationship when those terminals 28a, 54, and
86 are connected to each other, a work load when manufacturing the
air flow meter 14 can be reduced. Further, when the terminals 28a,
54, and 86 are connected by spot welding, the electrodes of a
welding jig and the terminals 28a, 54, and 86 can be stably brought
into contact with each other, so that a welding strength can be
likely to be increased. As the welding for connecting the terminals
28a, 54, and 86, laser welding or the like may be used in addition
to the spot welding. The terminals 28a, 54, and 86 may be
electrically connected to each other by wire bonding, soldering, or
the like.
[0205] The terminal unit 85 is fixed to the housing body 24 by the
terminal fixing portion 87 being caught by the sealing step surface
67 or the like. In that case, the terminal unit 85 is positioned
with respect to the housing body 24 in the height direction Y by
the sealing step surface 67.
[0206] In FIG. 18, the housing body 24 is not shown, and the
housing opening 61 and the potting portion 65 are indicated in
virtual lines. In FIG. 19, the housing body 24 is illustrated, but
the potting portion 65 is not illustrated. Each of the bridge
terminals 86 may have a fit portion for fitting the connector
terminal 28a and the lead terminal 54. In the above configuration,
there is no need to perform spot welding on the terminals 28a, 54,
and 86.
[0207] A signal from the temperature sensing element 23a is output
from the connector portion 28 in the order of the intake air
temperature terminals 23c, the bridge terminals 86, the lead
terminals 54, the circuit chip 81, the lead terminals 54, the
bridge terminals 86, and the connector terminals 28a.
[0208] In the sensor SA 50, a flow rate signal corresponding to the
flow rate of the intake air flowing through the measurement flow
channel 32 is output from the flow rate detector 22 to the circuit
chip 81, and the flow rate signal is processed by the circuit chip
81 to calculate the flow rate of the intake air in the intake
passage 12. The flow rate calculated by the circuit chip 81 is
transmitted to the ECU 20 by transmitting a signal through the lead
terminals 54 and the connector terminals 28a. As described above,
the air flow meter 14 detects the flow rate of the intake air
flowing through the intake passage 12 by the flow rate detector
22.
[0209] As described above, in the sealing region PA, the terminals
28a, 54, and 86 are sealed by the potting portion 65 so as not to
be exposed. As shown in FIGS. 8 and 21, the housing body 24 has a
lip 89 extending along the peripheral portion of the housing
opening 61. The lip 89 circumferentially surrounds the housing
opening 61 in an annular shape, and has a function of regulating
the molten resin from flowing out of the housing opening 61 when
the potting portion 65 is formed. In the housing 21, the flange
portion 27 exists on an outer peripheral side of the lip 89.
[0210] As shown in FIG. 21, a surface of the potting portion 65 is
located at a position separated from the housing opening 61 toward
the housing tip side in the height direction Y. The surface does
not extend straight in the width direction X and the depth
direction Z, but is disposed at a position closer to the housing
opening 61 as the surface of the potting portion 65 is closer to
the inner peripheral surface of the housing body 24. This is
because a phenomenon occurs in which the molten resin filled in the
sealing region PA creeps up the inner peripheral surface of the
housing body 24 when the potting portion 65 is formed. The creep-up
phenomenon of the molten resin tends to occur particularly at
corner portions. On the other hand, in the present embodiment, as
shown in FIG. 3, since the housing opening 61 and the four corners
of the sealing region PA are curved surfaces, a phenomenon that the
molten resin creeps up is less likely to occur, as a result of
which, the molten resin is less likely to flows out of the housing
opening 61. In that case, voids and gaps are also less likely to
occur when the sealing region PA is filled with the molten
resin.
[0211] When an epoxy resin is selected as a thermosetting resin
used to form the potting portion 65, an epoxy resin is harder than
a urethane resin, for example, so that the positioning accuracy of
the sensor SA 50 can be enhanced. As the thermosetting resin
capable of forming the potting portion 65, in addition to the epoxy
resin, the urethane resin, a silicone resin, or the like can be
used.
[0212] Next, a mold device 90 for molding the housing 21 with resin
will be described with reference to FIGS. 22 to 26. As shown in
FIG. 22, the mold device 90 has an inner peripheral mold portion 91
for molding the inner peripheral surface of the housing body 24,
outer peripheral mold portions 102 and 103 for molding the outer
peripheral surface of the housing 21, a passage mold portion 104
for molding the passage flow channel 31, and root mold portions 105
and 106 for molding the root portion 29a.
[0213] The inner peripheral mold portion 91 has a mold main body
portion 92 and an inward portion 93. The mold main body portion 92
has a main body recess portion 92a for forming the outer peripheral
surface of the flange portion 27 and the connector portion 28, and
the inward portion 93 extends from a bottom surface of the main
body recess portion 92a in order to define the internal space 24a
of the housing body 24. When the direction defined for the air flow
meter 14 is also applied to the mold device 90, the main body
recess portion 92a is recessed in the height direction Y, and the
inward portion 93 extends in the height direction Y. A surface of
the inner peripheral surface of the main body recess portion 92a
facing in the height direction Y is referred to as a bottom
surface.
[0214] The inward portion 93 has a sealing molding portion 94 for
defining the sealing region PA and an open molding portion 95 for
defining the open region PB, and the open molding portion 95
extends from the sealing molding portion 94 in the height direction
Y. The open molding portion 95 has an accommodation molding portion
96 for defining the accommodation region PB1 and a measurement
molding portion 97 for defining the measurement region PB2, and the
measurement molding portion 97 extends from the accommodation
molding portion 96 in the height direction Y.
[0215] In FIGS. 22 to 24, the measurement molding portion 97 has a
detection molding portion 97a for defining the detection path 32a,
an introduction molding portion 97b for defining the introduction
path 32b, and a discharge molding portion 97c for defining the
discharge path 32c. The introduction molding portion 97b and the
discharge molding portion 97c extend from the detection molding
portion 97a in the height direction Y, and are both elongated
columnar members. The introduction molding portion 97b and the
discharge molding portion 97c are aligned laterally in the depth
direction Z in a state of being separated from each other, and the
detection molding portion 97a connects the introduction molding
portion 97b and the discharge molding portion 97c. The introduction
molding portion 97b corresponds to an introduction column portion,
the discharge molding portion 97c corresponds to a discharge column
portion, and the detection molding portion 97a corresponds to a
columnar connection portion.
[0216] The inner peripheral mold portion 91 is configured so that
the inward portion 93 can be extracted from the housing opening 61
when the housing 21 is molded with resin. More specifically, in the
inward portion 93, the sealing molding portion 94, the
accommodation molding portion 96, the detection molding portion
97a, the introduction molding portion 97b, and the discharge
molding portion 97c may be thinned or unchanged toward the tip
portion of the inward portion 93, but are not thickened. Further,
even if a step surface facing the tip side of the inward portion 93
is formed on an outer peripheral surface of the inward portion 93,
a step surface facing a base end side of the inward portion 93 is
not formed. Therefore, in the inward portion 93, a width dimension
in the width direction X and a depth dimension in the depth
direction Z may be smaller or unchanged toward the tip portion of
the inward portion 93 but are not larger. In this example, the tip
portion of the inner peripheral mold portion 91 is a side of the
introduction molding portion 97b and the discharge molding portion
97c which is not connected to the detection molding portion
97a.
[0217] In particular, in FIG. 23 and FIG. 24, a separation distance
L1 between the introduction molding portion 97b and the discharge
molding portion 97c may be larger or unchanged toward the tip
portion of the inward portion 93, but are not smaller. A separation
distance L2 between the outer surfaces of the introduction molding
portion 97b and the discharge molding portion 97c may be smaller or
unchanged toward the tip portion of the inward portion 93, but are
not larger. Further, when one way in the width direction X is
referred to as a right way and the other way is referred to as a
left way, a separation distance between a right surface of the
outer peripheral surface of the introduction molding portion 97b
facing rightward and a left surface of the outer peripheral surface
of the discharge molding portion 97c facing leftward does not
increase toward the tip portion of the inward portion 93.
Similarly, a separation distance between a left surface of the
introduction molding portion 97b and a right surface of the
discharge molding portion 97c does not increase toward the tip
portion of the inward portion 93.
[0218] The passage mold portion 104 is configured so as to be
extractable from the inflow port 33a when the housing 21 is molded
with resin. Specifically, in FIGS. 22, 25, and 26, the passage mold
portion 104 is an elongated columnar member extending in the depth
direction Z. In the passage mold portion 104, when a portion for
forming the outflow port 33b is referred to as a tip portion, the
passage mold portion 104 may be thinner or unchanged toward the tip
portion of the passage mold portion 104, but is not thicker.
Further, even if a step surface facing the tip side of the passage
mold portion 104 is formed on the outer peripheral surface of the
passage mold portion 104, a step surface facing the base end side
of the passage mold portion 104 is not formed. Therefore, in the
passage mold portion 104, the width dimension in the width
direction X and the height dimension in the height direction Y may
be smaller or unchanged toward the tip portion of the passage mold
portion 104, but are not larger.
[0219] Returning to the description of FIG. 22, the pair of outer
peripheral mold portions 102 and 103 are aligned side by side in
the width direction X. The width direction X is a direction
orthogonal to the depth direction Z, which is an alignment
direction of the introduction molding portion 97b and the discharge
molding portion 97c in the inner peripheral mold portion 91. A
housing recess portion 111 for molding the housing 21 and a mold
recess portion 112 for accommodating the passage mold portion 104
and the root mold portions 105 and 106 are formed in the pair of
outer peripheral mold portions 102 and 103. In the outer peripheral
surface of the flange portion 27 and the outer peripheral surface
of the connector portion 28, portions different from each other are
molded in the main body recess portion 92a of the inner peripheral
mold portion 91 and the housing recess portion 111 of the outer
peripheral mold portions 102 and 103. The outer peripheral mold
portions 102 and 103 each have an outlet extension portion 113 for
defining the measurement outlet 33c, and the outlet extension
portion 113 extends in the width direction X from a bottom surface
of the mold recess portion 112 for the housing 21. In addition, the
first outer peripheral mold portion 102 has a mold portion (not
shown) that enters an interior of the main body recess portion 92a
of the inner peripheral mold portion 91 in order to form the inner
peripheral surface of the connector portion 28, and a recess
portion in order to form the protective protrusion 29b.
[0220] The first outer peripheral mold portion 102 corresponds to a
first mold portion, and the second outer peripheral mold portion
103 corresponds to a second mold portion. The width direction X in
which the outlet extension portion 113 extends is also an alignment
direction of the first outer peripheral mold portion 102 and the
second outer peripheral mold portion 103.
[0221] The pair of root mold portions 105 and 106 are aligned side
by side in the depth direction Z between the first outer peripheral
mold portion 102 and the second outer peripheral mold portion 103.
In the root mold portions 105 and 106, recess portions for molding
the root portion 29a are provided on the respective tip end faces.
The recess portion of the first root mold portion 105 has a shape
corresponding to the upstream-side end face of the root portion
29a, and the recess portion of the second root mold portion 106 has
a shape corresponding to the downstream-side end face of the root
portion 29a.
[0222] Next, as a method of manufacturing the air flow meter 14, a
method of manufacturing the housing 21 with the use of the mold
device 90 will be described. The method of manufacturing the air
flow meter 14 corresponds to a method of manufacturing the physical
quantity measurement device.
[0223] First, the mold portions 91 and 102 to 106 are prepared for
the mold device 90. Then, those mold portions 91 and 102 to 106 are
assembled together. For example, the first outer peripheral mold
portion 102 and the second outer peripheral mold portion 103 are
fixed to each other with their respective recess portions facing
each other, and the inward portion 93 of the inner peripheral mold
portion 91, the passage mold portion 104, and the root mold
portions 105 and 106 are inserted into the opening defined between
the outer peripheral mold portions 102 and 103. The opening is
defined by the respective mold recess portions 112 of the outer
peripheral mold portions 102 and 103, and the inward portion 93 of
the inner peripheral mold portion 91, the passage mold portion 104,
and the root mold portions 105 and 106, which have been inserted
from the opening slide inside the mold recess portion 112. In the
above step, the second outer peripheral mold portion 103 may be
mounted on the first outer peripheral mold portion 102 in a state
where the first outer peripheral mold portion 102 is installed on a
work table or the like, and the inward portion 93 of the inner
peripheral mold portion 91, the passage mold portion 104, and the
two root mold portions 105, 105 are mounted in the recess portion
of the first outer peripheral mold portion 102. In short, the above
step has only to assemble the mold device 90.
[0224] In the assembled state of the mold device 90, the outlet
extension portions 113 of the outer peripheral mold portions 102
and 103 abut against the discharge molding portion 97c of the inner
peripheral mold portion 91, thereby realizing a configuration in
which the measurement outlet 33c penetrates through the outer
peripheral portion of the housing 21. In the above state, the tip
end face of the passage mold portion 104 abuts against at least one
of the inner peripheral surfaces of the housing recess portions 111
of the outer peripheral mold portions 102 and 103, thereby
realizing a configuration in which the outflow port 33b penetrates
through the outer peripheral portion of the housing 21. In
addition, a configuration in which the tip portion of the passage
mold portion 104 extends beyond the introduction molding portion
97b and the tip end face abuts against both of the outer peripheral
mold portions 102 and 103 can be referred to as an inlay structure.
With the above inlay structure, an effect of inhibiting burrs
around the outflow port 33b can be obtained.
[0225] The intake air temperature terminals 23c and the connector
terminals 28a are preliminarily attached to the inner peripheral
mold portion 91 and the outer peripheral mold portions 102 and 103
in a state of being connected to each other before assembling the
mold device 90. As a result, even when the housing 21 is integrally
molded, a configuration in which the terminals 23c and 28a are
embedded in the housing 21 can be realized.
[0226] After assembly of the mold device 90 has been completed,
molten resin is injected into the mold device 90 through only one
injection port provided in the mold device 90. The injection port
is formed in, for example, the first outer peripheral mold portion
102, and the molten resin for integrally molding the entire housing
21 is completely filled into the inside of the mold device 90 by
one injection. Although the resin injection may be performed
multiple times, all of the molten resin divided into multiple
injections are used for integrally molding the housing 21. Unlike
the present embodiment, for example, when a housing is manufactured
by performing resin injection for molding the multiple members and
resin injection for joining those members to each other, it is
considered that the housing is not integrally molded.
[0227] After the molten resin filled in the gaps between the mold
portions 91, 102 to 106 has been cured in the mold device 90, the
mold portions 91, and 102 to 106 are removed from the housing body
24 by disassembling the mold device 90. For example, the housing 21
is removed from the outer peripheral mold portions 102 and 103 by
extracting the inward portion 93 of the inner peripheral mold
portion 91, the passage mold portion 104, and the root mold
portions 105 and 106 from the opening between the outer peripheral
mold portions 102 and 103 and separating the outer peripheral mold
portions 102 and 103 from each other. After the outer peripheral
mold portions 102 and 103 have been separated from each other, the
inner peripheral mold portion 91, the passage mold portion 104, and
the root mold portions 105 and 106 may be removed from the housing
21. In short, the housing 21 may be removed by disassembling the
mold device 90.
[0228] In this example, in the inner peripheral mold portion 91,
the inner peripheral surface of the housing body 24 can be
integrally molded by realizing a configuration in which the inward
portion 93 can be extracted from the housing opening 61 as
described above. For example, as shown in FIG. 24, the measurement
flow channel 32 is integrally molded by detaching the measurement
molding portion 97 from the inner peripheral surface of the housing
body 24. With respect to the passage mold portion 104, a
configuration in which the passage mold portion 104 can be
extracted from the inflow port 33a is realized as described above,
with the result that the inner peripheral surface of the passage
flow channel 31 can be integrally molded as shown in FIG. 26. When
molding the resin of the housing 21, the introduction molding
portion 97b reaches the outflow passage 31b beyond the flow channel
boundary portion 34. As a result, even if the outflow passage 31b
is inclined toward the housing base end side with respect to the
inflow passage 31a, the passage mold portion 104 can be avoided
from being caught by the longitudinal partition wall 69 so that the
passage mold portion 104 cannot be extracted from the inflow port
33a.
[0229] <Effects of Configuration Group A>
[0230] The effects of a configuration group A on integral molding
of the measurement flow channel will be described. According to the
present embodiment, since the housing 21 is integrally molded with
the use of the mold device 90, there is no need to manufacture the
housing 21 by separately molding the multiple members with resin
and then combining those members together. In that case, a step is
less likely to occur on the inner peripheral surface of the passage
flow channel 31 or the measurement flow channel 32 at the boundary
between the members, and the width dimensions of the passage flow
channel 31 and the measurement flow channel 32 are less likely to
vary from product to product in the width direction X. With a
reduction in the manufacturing variation in this manner, the
detection accuracy of the intake air amount by the flow rate
detector 22 can be enhanced.
[0231] According to the present embodiment, since the outer
peripheral surface of the housing 21 is formed using at least two
mold portions, that is, the first outer peripheral mold portion 102
and the second outer peripheral mold portion 103, the degree of
freedom of the outer peripheral shape of the housing 21 can be
enhanced. In addition, since the width direction X in which the
outer peripheral mold portions 102 and 103 are aligned in the mold
device 90 is orthogonal to the depth direction Z in which the
introduction path 32b and the discharge path 32c are aligned, the
depth dimension of the housing recess portions 111 is reduced as
compared with, for example, a configuration in which the outer
peripheral mold portions 102 and 103 are aligned in the depth
direction Z. In that case, since the molten resin is likely to
spread over the entire housing recess portions 111, a product
defect in which a part of the resin-molded housing 21 is missing
can be inhibited from occurring.
[0232] According to the present embodiment, since the outlet
extension portion 113 of the first outer peripheral mold portion
102 abuts against the inner peripheral mold portion 91 in the mold
device 90, the measurement outlet 33c penetrating through the outer
peripheral portion of the housing 21 can be molded by the mold
device 90. For that reason, a work load for providing the
measurement outlet 33c can be reduced as compared to a method in
which the measurement outlet 33c is provided by, for example,
molding the housing 21 and then performing a hole drilling process
on the outer peripheral portion of the housing 21. In addition, in
order to mold the measurement outlet 33c that penetrates through
the outer peripheral portion of the housing 21 in the width
direction X, the outlet extension portion 113 may be extended from
the first outer peripheral mold portion 102 in the width direction
X. For that reason, unlike the passage flow channel 31 molded with
the use of the passage mold portion 104, for example, there is no
need to use a dedicated mold portion for molding the measurement
outlet 33c separately from the first outer peripheral mold portion
102. In that case, the manufacturing cost of the mold device 90 can
be reduced as much as the dedicated mold portion is not used, and
further, the work load required for assembling the mold device 90
can be reduced by not using the dedicated mold portion.
[0233] According to the present embodiment, in the mold device 90,
since the passage mold portion 104 is aligned with the inner
peripheral mold portion 91 in the depth direction Z, a
configuration in which the inflow port 33a and the outflow port 33b
of the passage flow channel 31 are opened in the depth direction Z
can be realized by resin molding. For example, unlike the present
embodiment, in a configuration in which a dedicated portion for
providing the inflow port 33a and the outflow port 33b opened in
the depth direction Z is provided in the first outer peripheral
mold portion 102, it becomes difficult to remove the first outer
peripheral mold portion 102 from the housing 21 in the width
direction X.
[0234] According to the present embodiment, the flange portion 27
and the connector portion 28 extending from the housing body 24 in
the width direction X and the depth direction Z are molded by
combining the mold main body portion 92 of the inner peripheral
mold portion 91 and the outer peripheral mold portions 102 and 103.
In order to mold the flange portion 27 and the connector portion 28
in this manner, the mold main body portion 92 and the outer
peripheral mold portions 102 and 103 are combined together in the
height direction Y, thereby being capable of easily removing the
mold main body portion 92 and the outer peripheral mold portions
102 and 103 from the flange portion 27.
[0235] According to the present embodiment, in the mold device 90,
the inward portion 93 of the inner peripheral mold portion 91 is in
a state of entering the housing recess portion 111 of each of the
outer peripheral mold portions 102 and 103. In this case, after the
molten resin has been cured, the operator or the like can remove
the inner peripheral mold portion 91 from the housing 21 by pulling
out the inward portion 93 from the housing opening 61 in a state of
holding the mold main body portion 92. For that reason, the mold
device 90 which realizes the integral molding of the housing 21 can
be realized, and moreover, and the mold device 90 can be removed
from the housing 21.
[0236] According to the present embodiment, in the housing 21, the
internal space 24a is not narrowed even when the internal space 24a
comes closer to the housing opening 61 in the height direction Y.
For that reason, when the housing 21 is molded with resin by using
the mold device 90, the inward portion 93 of the inner peripheral
mold portion 91 can be extracted from the housing opening 61. This
makes it unnecessary to divide the portion defining the internal
space 24a in the housing 21 into multiple members. For example,
unlike the present embodiment, in the housing 21 in which the
internal space 24a is narrowed toward the housing opening 61, the
inward portion 93 is caught on the inner peripheral surface of the
narrowed portion, which makes it difficult to extract the inward
portion 93 from the housing opening 61. In the above configuration,
the portion defining the internal space 24a is divided into
multiple members, and those members are assembled together to
manufacture the internal space 24a, as a result of which, the
manufacturing variation as described above is likely to occur.
[0237] Moreover, if the internal space 24a is not narrowed toward
the housing base end side, the internal space 24a is narrowed
toward the housing tip side. In the above configuration, since the
measurement flow channel 32 and the passage flow channel 31 are
reduced in size as much as possible relative to the sensor SA 50,
the housing 21 can be downsized. In addition, when the housing 21
is downsized, the resin material used for manufacturing the housing
21 is reduced, so that the material cost required for manufacturing
the housing 21 can be reduced. In other words, the manufacturing
cost of the air flow meter 14 can be reduced.
[0238] According to the present embodiment, the region step surface
66 on which the sensor SA 50 is caught faces the housing opening
61. For that reason, the sensor SA 50 can be positioned by the
region step surface 66 in the height direction Y while the region
step surface 66 realizes a configuration in which the internal
space 24a is not narrowed toward the housing opening 61. Therefore,
when manufacturing the air flow meter 14, the operator can
accurately position the sensor SA 50 by easily inserting the sensor
SA 50 into the housing opening 61 to a position where the housing
opening 61 is caught by the region step surface 66.
[0239] According to the present embodiment, since the circuit step
surface 55 of the sensor SA 50 and the region step surface 66 of
the housing 21 are in contact with each other over the entire
circumference of the circuit step surface 55 and the housing 21,
the sealing region PA and the open region PB can be separated from
each other by the abutment portions of the circuit step surface 55
and the region step surface 66. In that case, since the molten
resin filled in the sealing region PA is restricted from flowing
into the open region PB at the time of manufacturing the potting
portion 65, the size and shape of the open region PB and the
measurement flow channel 32 can be avoided from being
unintentionally changed by the molten resin.
[0240] According to the present embodiment, even if the
longitudinal partition wall 69 that separates the introduction path
32b and the discharge path 32c in the open region PB is not thinner
even if the longitudinal partition wall 69 comes closer to the
housing opening 61 in the height direction Y. For that reason, the
introduction molding portion 97b and the discharge molding portion
97c can be extracted from the introduction path 32b and the
discharge path 32c in the inward portion 93 of the inner peripheral
mold portion 91. This makes it possible to realize a configuration
in which the inward portion 93 of the inner peripheral mold portion
91 can be extracted from the housing opening 61.
[0241] According to the present embodiment, since the detection
throttle portion 59 is provided in the detection path 32a of the
measurement flow channel 32, the flow velocity of the intake air
passing through the flow rate detector 22 tends to be increased,
and thus the detection accuracy of the flow rate detector 22 can be
enhanced. The detection throttle portion 59 does not become thick
even when the detection throttle portion 59 comes closer to the
housing opening 61 in the height direction Y, extends from the
longitudinal partition wall 69 toward the housing opening 61 side,
and is not thicker than the longitudinal partition wall 69. For
that reason, when molding the resin of the housing 21, the inward
portion 93 of the inner peripheral mold portion 91 can be removed
from the longitudinal partition wall 69 and the detection throttle
portion 59.
[0242] According to the present embodiment, since the passage flow
channel 31 is provided closer to the housing tip side than the
measurement region PB2, a configuration can be realized in which
the measurement flow channel 32 is molded by the inward portion 93
of the inner peripheral mold portion 91 and the passage flow
channel 31 is molded by the passage mold portion 104. In the above
configuration, there is a need to make the depth direction Z in
which the passage mold portion 104 is extracted from the passage
flow channel 31 orthogonal to the height direction Y in which the
inward portion 93 is extracted from the housing opening 61. For
that reason, even if the lateral partition wall 68 that separates
the detection path 32a and the passage flow channel 31 from each
other extends in the depth direction Z, the lateral partition wall
68 can be molded by the passage mold portion 104 and the inward
portion 93 of the inner peripheral mold portion 91. Therefore, even
if the housing 21 includes the lateral partition wall 68 extending
in the depth direction Z, the housing 21 can be integrally
molded.
[0243] Unlike the present embodiment, there is a physical quantity
measurement device in which a measurement flow channel is defined
by a combination of multiple members. The physical quantity
measurement device has a pair of covers facing each other and a
main body portion provided between the covers. In the physical
quantity measurement device, a sub-passage is provided between the
cover and the main body portion or between a pair of covers, and a
flow rate detector for detecting a flow rate of the intake air is
provided in the sub passage. The pair of covers and the main body
portion are formed independently of each other by a resin molding
process of injecting a thermoplastic resin into a mold, and are
assembled together to provide sub-passage.
[0244] However, in a configuration in which the sub-passage is
defined by multiple members such as the pair of covers and the main
body portion, there is a concern that the shape, size, and the like
of the sub-passage may vary from product to product due to a
positional deviation between those members. For example, when the
position at which the pair of covers are attached to the main body
portion deviates from each other in the thickness direction of the
housing, the flow channel area of the sub-passage varies from
product to product. On the other hand, according to the present
embodiment, the manufacturing variation of the measurement flow
channel for measuring the physical quantity can be reduced.
[0245] <Description of Configuration Group B>
[0246] A configuration group B relating to the position of the
measurement outlet will be described with reference to FIG. 27,
FIG. 28, and the like. Although FIG. 6, FIG. 7, and the like show
that the thinned portions 41 are provided on the flat surface 44 on
the outer peripheral surface of the housing 21, a description will
be advanced on the assumption that the thinned portions 41 are not
provided on the flat surface 44.
[0247] As shown in FIGS. 27 and 28, in the outer peripheral surface
of the housing 21, the upstream end portion is referred to as an
outer peripheral upstream end 132a, and the downstream end portion
is referred to as an outer peripheral downstream end 132b. In that
case, the housing 21 has a curved surface 45 formed by gradually
decreasing the thickness in the width direction X from the flat
surface 44 toward the outer peripheral upstream end 132a in the
depth direction Z. In that case, in the housing 21, the width
dimension in the width direction X gradually decreases toward the
outer peripheral upstream end 132a.
[0248] On the outer peripheral surface of the housing 21, there are
boundaries 131a and 131b between the flat surface 44 and the curved
surface 45. The vertical boundary 131a extends in the height
direction Y, and the lateral boundary 131b extends in the depth
direction Z. If a surface of outer peripheral surfaces of the
housing 21 on the connector portion 28 side is referred to as a
front surface and a surface on the opposite side to the front
surface is referred to as a back surface, the front surface and the
back surface are aligned in the width direction X and are a pair of
side surfaces included in the outer peripheral surface of the
housing 21. The outer peripheral upstream end 132a is a boundary
between the front curved surface 45 and the back curved surface 45,
and extends in the height direction Y. On the other hand, the outer
peripheral downstream end 132b is a plane extending in the width
direction X and the height direction Y. The outflow port 33b is
provided at the outer peripheral downstream end 132b.
[0249] On the outer peripheral surface of the housing 21, the flat
surface 44, the curved surface 45, and the measurement outlet 33c
all have a longitudinally long shape extending in the height
direction Y. In particular, the measurement outlet 33c has a flat
shape extending along the vertical boundary 131a in a state of
extending across the vertical boundary 131a in the depth direction
Z. In the measurement outlet 33c, the longitudinal dimension in the
height direction Y is larger than the lateral dimension in the
depth direction Z. The open area of the measurement outlet 33c is
smaller than the open area of the inflow port 33a.
[0250] In the height direction Y, a height dimension H11 of the
flat surface 44 is larger than both a height dimension H12 of the
curved surface 45 and a height dimension H13 of the measurement
outlet 33c, and the height dimension H12 of the curved surface 45
is larger than the height dimension H13 of the measurement outlet
33c. In the height direction Y, the curved surface 45 and the
measurement outlet 33c are disposed at an intermediate position of
the flat surface 44, and the measurement outlet 33c is disposed at
an intermediate position of the flat surface 44. In that case, both
one end portion of the curved surface 45 on the housing tip side
and the other end portion on the housing base end side are included
in the lateral boundary 131b.
[0251] On the outer peripheral surface of the housing 21, there is
the vertical boundary 131a between the outer peripheral upstream
end 132a and the outer peripheral downstream end 132b, and the
vertical boundary 131a is located closer to the outer peripheral
upstream end 132a. In that case, in the depth direction Z, a length
dimension L11 of the flat surface 44 is larger than a length
dimension L12 of the curved surface 45. A length dimension L13 of
the measurement outlet 33c is smaller than both the length
dimension L11 of the flat surface 44 and the length dimension L12
of the curved surface 45. The depth direction Z is an alignment
direction of the outer peripheral upstream end 132a and the outer
peripheral downstream end 132b, and the flat surface 44 extends in
the alignment direction. Among the directions extending along the
flat surface 44, the height direction Y corresponds to a direction
orthogonal to the alignment direction.
[0252] The measurement outlet 33c is disposed at a position closer
to the outer peripheral upstream end 132a in the depth direction Z.
In that case, a separation distance L14 between the measurement
outlet 33c and the outer peripheral upstream end 132a is smaller
than a separation distance L15 between the measurement outlet 33c
and the outer peripheral downstream end 132b. In this example, when
an upstream end portion of the measurement outlet 33c is referred
to as an outlet upstream end 134a, and a downstream end portion of
the measurement outlet 33c is referred to as an outlet downstream
end 134b, a vertical boundary 131a is located closer to the outlet
upstream end 134a in the depth direction Z. In that case, in the
depth direction Z, a separation distance L16 between the outlet
upstream end 134a and the vertical boundary 131a is smaller than a
separation distance L17 between the outlet downstream end 134b and
the vertical boundary 131a.
[0253] The inner peripheral surface of the measurement flow channel
32 has defining surfaces 135a to 135c that define the measurement
outlet 33c. A through hole for forming the measurement outlet 33c
is provided in the outer peripheral portion of the housing 21, and
the defining surfaces 135a to 135c are included in the inner
peripheral surface of the through hole. The upstream defining
surfaces 135a forms the outlet upstream end 134a of the measurement
outlet 33c, and is orthogonal to the flat surface 44 because the
upstream defining surface 135a faces the downstream side in a state
of being orthogonal to the depth direction Z. The downstream
defining surface 135b forms the outlet downstream end 134b, and is
inclined with respect to the flat surface 44 by being inclined
toward the upstream side in a state of being inclined toward the
outer peripheral side. A pair of the connection defining surfaces
135c connect the upstream defining surface 135a and the downstream
defining surface 135b, and the pair of the defining surfaces 135a
and 135b are provided to sandwich the defining surfaces 135a and
135b. Each connection defining surface 135c is orthogonal to the
height direction Y.
[0254] The downstream defining surface 135b is an inclined surface
extending straight from the outlet downstream end 134b toward the
inner peripheral side of the housing 21, and is not orthogonal to
the downstream flat portion 137a. The downstream defining surface
135b provided on each of the front side and the back side of the
housing 21 is a tapered surface in which the housing 21 is thinned
toward the outlet upstream end 134a of the measurement outlet 33c.
An inclination angle .theta.1 of the downstream defining surface
135b with respect to the flat surface 44 such as the downstream
flat portion 137a is, for example, 30 degrees. The inclination
angle .theta.1 may be larger or smaller than 30 degrees, but is
preferably equal to or smaller than 30 degrees.
[0255] The flat surface 44 has a downstream flat portion 137a, a
tip-side flat portion 137b, and a base end-side flat portion 137c.
The downstream flat portion 137a extends from the measurement
outlet 33c toward the outer peripheral downstream end 132b in the
depth direction Z. The tip-side flat portion 137b extends from the
downstream flat portion 137a toward the housing tip side, and the
base end-side flat portion 137c extends from the downstream flat
portion 137a toward the housing base end side. In that case, the
downstream flat portion 137a is disposed between the tip-side flat
portion 137b and the base end-side flat portion 137c in the height
direction Y.
[0256] The tip-side flat portion 137b also has a portion of the
measurement outlet 33c and the curved surface 45 which goes around
the housing tip side, and the portion extends toward the housing
tip side from the measurement outlet 33c and the curved surface 45.
The base end-side flat portion 137c also includes a portion of the
measurement outlet 33c and the curved surface 45 which goes around
the housing base end side, and the portion extends toward the
housing base end side from the measurement outlet 33c and the
curved surface 45.
[0257] The degree of bending of the curved surface 45 is not
uniform, and a portion having the largest degree of bending of the
curved surface 45 is disposed at a position closer to the outer
peripheral upstream end 132a in the depth direction Z. For that
reason, since the measurement outlet 33c is disposed at a position
extending across the vertical boundary 131a, the measurement outlet
33c is disposed at a portion having the smallest degree of bending
which is the downstream end portion of the curved surface 45, and
when the measurement outlet 33c is viewed from the upstream side,
the measurement outlet 33c appears as an elongated shape extending
in the depth direction Z. In that case, unlike the present
embodiment, the width dimension W11 of the measurement outlet 33c
in the width direction X is smaller than, for example, a
configuration in which the measurement outlet 33c is disposed at a
position separated from the downstream end portion of the curved
surface 45 toward the outer peripheral upstream end 132a.
[0258] The curved surface 45 has an upstream curved portion 138a, a
tip-side curved portion 138b, and a base end-side curved portion
138c. The upstream curved portion 138a extends from the measurement
outlet 33c toward the outer peripheral upstream end 132a in the
depth direction Z. The tip-side curved portion 138b extends from
the upstream curved portion 138a toward the housing tip side, and
the base end-side curved portion 138c extends from the upstream
curved portion 138a toward the housing base end side. In that case,
the upstream curved portion 138a is disposed between the tip-side
curved portion 138b and the base end-side curved portion 138c in
the height direction Y.
[0259] The tip-side curved portion 138b has a portion of the
measurement outlet 33c which extends around the housing tip side,
and the portion enters between the measurement outlet 33c and the
tip-side flat portion 137b, and extends from the measurement outlet
33c toward the housing tip side. The base end-side curved portion
138c has a portion of the measurement outlet 33c which extends
around the housing base end side, and the portion enters between
the measurement outlet 33c and the base end-side flat portion 137c,
and extends from the measurement outlet 33c toward the housing base
end side.
[0260] The flat surface 44 corresponds to an outer peripheral flat
surface, and the curved surface 45 corresponds to an outer
peripheral inclined surface inclined with respect to the outer
peripheral flat surface. In the flat surface 44, the tip-side flat
portion 137b and the base end-side flat portion 137c correspond to
an extended flat portion, and in the curved surface 45, the
upstream curved portion 138a corresponds to an upstream inclined
portion, and the tip-side curved portion 138b and the base end-side
curved portion 138c correspond to an extended inclined portion. The
vertical boundary 131a corresponds to an outer peripheral
boundary.
[0261] In addition, when the width direction X is referred to as a
first direction, and the respective surfaces located on both sides
of the housing 21 in the first direction is referred to as a first
surface and a second surface, the flat surface 44 and the curved
surface 45 are included in each of the first surface and the second
surface. When the depth direction Z is referred to as a second
direction, the outer peripheral upstream end 132a is referred to as
a third surface, and the outer peripheral downstream end 132b is
referred to as a fourth surface, the third surface and the fourth
surface are located on both sides of the housing 21 in the second
direction. The measurement outlet 33c is provided on each of the
first surface and the second surface, and is opened toward the
outside of the housing 21 so as not to face the fourth surface side
in the second direction.
[0262] Next, a flow of the intake air generated on the outer
peripheral side of the housing 21 in the intake passage 12 will be
described with reference to FIG. 28.
[0263] Of the intake air flowing forward through the intake passage
12, an air AF1 reaching the outer peripheral upstream end 132a of
the housing 21 reaches the measurement outlet 33c while changing a
flow direction of the intake air flowing along the upstream curved
portion 138a of the curved surface 45. In that instance, when the
air AF1 reaches the measurement outlet 33c, the flow direction of
the air AF1 is closer to an alignment direction of the outlet
upstream end 134a and the outlet downstream end 134b, and the air
AF1 is less likely to flow into the measurement outlet 33c. For
that reason, a backflow in which the air AF1 flows into the
measurement outlet 33c is less likely to occur, and the measurement
outlet 33c is less likely to receive a dynamic pressure from the
air AF1 at the time of a forward flow.
[0264] Further, the air whose flow direction is gradually changed
by proceeding along the curved surface 45 is less likely to be
separated from the flat surface 44 when reaching the flat surface
44. For that reason, in the periphery of the measurement outlet 33c
and the periphery of the vertical boundary 131a, a turbulence of
the air flow attributable to the separation of the air flow from
the flat surface 44 is less likely to occur, and the flow of the
air is more likely to be stabilized. In that case, since the
pressure applied from the air to the measurement outlet 33c is
likely to be stabilized, the flow of the air in the measurement
flow channel 32 is also likely to be stabilized.
[0265] The air AF2 flowing along the downstream flat portion 137a
of the flat surface 44 travels in the depth direction Z even after
passing through the downstream end portion of the downstream flat
portion 137a, so that the air is separated from the outer
peripheral surface of the housing 21. Along with the separation of
the air AF2, the turbulence of the air flow such as a vortex is
likely to occur in the periphery of the outer peripheral downstream
end 132b or the like on the downstream side of the downstream flat
portion 137a. Due to the turbulence of the air flow, an air AF3
that flows backward toward the outer peripheral downstream end 132b
may occur in the vicinity of the outer peripheral downstream end
132b. In the present embodiment, the backflow of only a part of the
air such as the air AF3 is referred to as a partial backflow.
[0266] Unlike the present embodiment, for example, in the
configuration in which the measurement outlet is provided at the
outer peripheral downstream end 132b or the like downstream of the
downstream flat portion 137a, the backflow of the airflow AF3
flowing into the measurement outlet is likely to occur. On the
other hand, since the measurement outlet 33c of the present
embodiment is not disposed downstream of the downstream flat
portion 137a, the airflow AF3 does not flow into the measurement
outlet 33c.
[0267] When the entire backflow in which the intake air flows
backward in the entire intake passage 12 occurs, when an air AF4
flowing backward in the intake passage 12 reaches the outer
peripheral downstream end 132b, the outer peripheral downstream end
132b receives a dynamic pressure from the air AF4. For that reason,
unlike the present embodiment, in the configuration in which the
measurement outlet opened toward the downstream side is provided at
the outer peripheral downstream end 132b or the like, the
measurement outlet receives the dynamic pressure from the air AF4.
On the other hand, since the measurement outlet 33c of the present
embodiment is not provided at the outer peripheral downstream end
132b and is not open toward the downstream side, the measurement
outlet 33c does not receive the dynamic pressure from the air AF4.
In addition, a backflow of the air AF4 flowing into the measurement
outlet 33c does not occur.
[0268] After flowing into the inflow port 33a, an air AF5 flowing
out from the measurement outlet 33c through the measurement flow
channel 32 flows along the downstream defining surface 135b, so
that the air easily flows along the downstream flat portion 137a
after flowing out from the measurement outlet 33c. In that
instance, after the air AF5 has flowed out from the measurement
outlet 33c, the air AF5 is less likely to separate from the
downstream flat portion 137a, and the turbulence of the air flow
such as a vortex flow is less likely to be generated in the
vicinity of the measurement outlet 33c with the separation of the
air flow AF5 from the downstream flat portion 137a.
[0269] Unlike the present embodiment, for example, in a
configuration in which the downstream defining surface 135b is
orthogonal to the flat surface 44 similarly to the upstream
defining surface 135a, the air AF6 flowing out from the measurement
outlet 33c proceeds in a direction orthogonal to the flat surface
44. In this example, it is considered that a turbulence of the air
flow such as a vortex flow is likely to occur in the vicinity of
the measurement outlet 33c due to, for example, a large difference
between a traveling direction of the air AF6 and a traveling
direction of the air flowing forward in the depth direction Z from
the outer peripheral side of the housing 21. Further, in that
instance, it can be considered that the air AF6 flows out from the
measurement outlet 33c to be separated from the downstream flat
portion 137a, and the turbulence of the air flow is likely to occur
in the vicinity of the measurement outlet 33c in association with
the separation of the air.
[0270] In the configuration group B according to the present
embodiment, the measurement outlet 33c is not opened toward the
outer peripheral downstream end 132b. For that reason, even if a
partial backflow of the air AF3 or the like or an entire backflow
of the air AF4 or the like occurs in the intake passage 12, the
intake air is less likely to flow into the measurement outlet 33c
in association with the backflow. In that case, since the flow of
the intake air in the measurement flow channel 32 is not likely to
be disturbed by the partial backflow or the entire backflow, the
deterioration of the accuracy of the flow rate detection by the
flow rate detector 22 can be inhibited. Further, even if the entire
backflow occurs, the dynamic pressure due to the entire backflow is
less likely to be received by the measurement outlet 33c, so that
the flow of the intake air in the measurement flow channel 32 is
less likely to be disturbed by the entire backflow. This also makes
it possible to inhibit the deterioration of the accuracy of the
flow rate detection by the flow rate detector 22. Therefore, the
measurement accuracy of the intake air amount by the air flow meter
14 can be improved.
[0271] According to the present embodiment, in the flat surface 44,
since the downstream flat portion 137a extends from the measurement
outlet 33c toward the downstream side, a configuration can be
realized in which the measurement outlet 33c is not opened toward
the downstream side. In that case, the measurement outlet 33c and
the outer peripheral downstream end 132b are separated from each
other in the depth direction Z by an amount corresponding to the
downstream flat portion 137a. For that reason, even if the
turbulence of the air due to the partial backflow or the entire
backflow occurs around the outer peripheral downstream end 132b in
the intake passage 12, the downstream flat portion 137a can inhibit
the turbulence from reaching the measurement outlet 33c.
[0272] According to the present embodiment, on the outer peripheral
surface of the housing 21, the tip-side flat portion 137b and the
base end-side flat portion 137c are also disposed between the
measurement outlet 33c and the outer peripheral downstream end 132b
in addition to the downstream flat portion 137a. For that reason,
even if the turbulence of the air flow occurs at a position closer
to the housing tip side or the housing base end side than the
measurement outlet 33c in the position around the outer peripheral
downstream end 132b, the flat portions 137b and 137c can inhibit
the turbulence from reaching the measurement outlet 33c.
[0273] According to the present embodiment, in the flat surface 44,
the upstream curved portion 138a extends from the measurement
outlet 33c toward the upstream side. For that reason, the forward
flow air such as the air AF1 reaching the outer peripheral upstream
end 132a of the housing 21 flows along the upstream curved portion
138a, so that the forward flow air is likely to flow along the
measurement outlet 33c, and is less likely to flow into the
measurement outlet 33c. In that case, since the dynamic pressure
due to the forward flow air is less likely to be applied to the
measurement outlet 33c, the turbulence of the air flow in the
measurement flow channel 32 due to the dynamic pressure and the
deterioration of the detection accuracy of the flow rate detector
22 can be inhibited.
[0274] In addition, in the depth direction Z, the measurement
outlet 33c is disposed at the downstream end portion of the curved
surface 45 in the curved surface 45 in which a portion having the
largest degree of bending is disposed at the position closer to the
outer peripheral upstream end 132a. In that case, since the
measurement outlet 33c is hardly opened toward the upstream side,
the probability that the air, which has proceeded straight in the
depth direction Z among the forward flow air, directly reaches the
measurement outlet 33c is low. This makes it difficult to cause the
forward flow air to flow into the measurement outlet 33c and to
apply the dynamic pressure to the measurement outlet 33c.
[0275] According to the present embodiment, on the outer peripheral
surface of the housing 21, the tip-side curved portion 138b and the
base end-side curved portion 138c are also disposed between the
measurement outlet 33c and the outer peripheral upstream end 132a
in addition to the upstream curved portion 138a. For that reason,
among the forward flow air flowing along the curved surface 45, the
air flowing obliquely to the depth direction Z also flows along the
curved portions 138b and 138c, so that the traveling direction in
the width direction X is changed so as to be less likely to flow
into the measurement outlet 33c. In that case, the dynamic pressure
due to the forward flow air can be made less likely to be applied
to the measurement outlet 33c.
[0276] According to the present embodiment, the downstream defining
surface 135b defining the outlet downstream end 134b of the
measurement outlet 33c is not orthogonal to the depth direction Z,
but inclined toward the outer peripheral side of the housing 21.
For that reason, since the air AF5 flowing out from the measurement
outlet 33c flows along the downstream defining surface 135b, the
traveling direction of the air is likely to come closer to the
traveling direction of the forward flow air flowing through the
intake passage 12. In that instance, since the air AF5 is less
likely to be separated from the downstream flat portion 137a, the
turbulence of the air flow attributable to the separation is less
likely to occur around the measurement outlet 33c. Therefore, the
detection accuracy of the flow rate detector 22 can be inhibited
from being deteriorated due to the fact that the air flowing
through the measurement flow channel 32 is less likely to flow out
from the measurement outlet 33c.
[0277] According to the present embodiment, the measurement outlet
33c is disposed at a position closer to the outer peripheral
upstream end 132a in the depth direction Z. In that case, since the
separation distance between the outer peripheral downstream end
132b and the measurement outlet 33c in the housing 21 is as large
as possible, even if turbulence of the air flow accompanied by the
backflow occurs around the outer peripheral downstream end 132b,
the turbulence can be more reliably inhibited from reaching the
measurement outlet 33c.
[0278] According to the present embodiment, since the open area of
the measurement outlet 33c is smaller than the open area of the
inflow port 33a, the forward flow air such as the air AF1 is more
likely to flow into the measurement outlet 33c than into the inflow
port 33a. For that reason, the forward flow air can be inhibited
from flowing into the measurement outlet 33c.
[0279] According to the present embodiment, the measurement outlet
33c has a flat shape extending in the height direction Y. For that
reason, when a placement region in which the measurement outlet 33c
is necessarily to be placed is set in the intake passage 12, even
if an insertion depth of the air flow meter 14 into the airflow
insertion hole 12b varies somewhat from vehicle to vehicle, a part
of the measurement outlet 33c can be reliably placed in the
placement region. In that case, unlike the present embodiment, for
example, a separation distance between the measurement outlet 33c
and the outer peripheral downstream end 132b in the depth direction
Z is larger than that in the configuration in which the measurement
outlet 33c is flat and extends in the depth direction Z. Therefore,
even if turbulence of the air flow occurs around the outer
peripheral downstream end 132b in the intake passage 12, the flat
surface 44 can inhibit the turbulence from reaching the measurement
outlet 33c.
[0280] <Description of Configuration Group C>
[0281] A configuration group C relating to a positional
relationship between the housing attachment and the position holder
will be described with reference to FIGS. 29 and 30 and the like.
In FIG. 30, the connector terminals 28a, the SA protrusions 71a and
71b, and the width housing protrusion 72a are not shown.
[0282] As shown in FIG. 8, FIG. 29, and FIG. 30, in the housing 21,
the region step surface 66 is disposed closer to the housing tip
side than the ring holding portion 25. The housing body 24 has an
accommodation wall portion 121 defining the accommodation region
PB1 and a sealing wall portion 122 defining the sealing region PA,
and both of the wall portions 121 and 122 are cylindrical portions
extending in the height direction Y. The sealing wall portion 122
is provided closer to the housing base end side than the
accommodation wall portion 121, and the sealing wall portion 122
and the accommodation wall portion 121 are connected to each other
by an overhanging portion 66a. In that case, the overhanging
portion 66a is also included in the housing body 24, and the
overhanging portion 66a corresponds to a housing connector. The
accommodation wall portion 121 corresponds to a housing wall
portion.
[0283] The sealing wall portion 122 has an inner peripheral surface
disposed closer to the outer peripheral side than the inner
peripheral surface of the accommodation wall portion 121, and has
an outer peripheral surface disposed closer to the outer peripheral
side than the outer peripheral surface of the accommodation wall
portion 121. In the overhanging portion 66a, an intermediate
portion between the accommodation wall portion 121 and the sealing
wall portion 122 bulges to the outer peripheral side. The
overhanging portion 66a has a lateral extending portion 66b
extending from the accommodation wall portion 121 toward the outer
peripheral side and a vertical extending portion 66c extending from
the sealing wall portion 122 toward the housing tip side, and the
connection portions of those extending portions 66b and 66c are
chamfered by curved surfaces. The lateral extending portion 66b
corresponds to an orthogonal portion extending in a direction
orthogonal to the height direction Y.
[0284] In the housing 21, a housing attachment attached to the
intake pipe 12a includes the ring holding portion 25, the flange
portion 27, and the sealing wall portion 122. The ring holding
portion 25, the flange portion 27, and the sealing wall portion 122
have a shape in which the housing attachment as a whole extends in
the width direction X and the depth direction Z along the
peripheral portion of the housing 21. In that case, the height
direction Y is orthogonal to a direction in which the housing
attachment extends. The ring holding portion 25 is fixed to the
intake pipe 12a through an O-ring 26, and the flange portion 27 is
fixed to the intake pipe 12a through the bosses 12d. In that case,
a load for fixing the air flow meter 14 to the intake pipe 12a is
applied to the sealing wall portion 122 through the ring holding
portion 25 and the flange portion 27. Therefore, since the sealing
wall portion 122 is thickened as a whole, a strength of the sealing
wall portion 122 is increased.
[0285] In the sealing wall portion 122, an outer peripheral end of
a lateral cross section is generally circular, while an inner
peripheral end of the lateral cross section is generally
rectangular. The sealing wall portion 122 enters the airflow
insertion hole 12b of the intake pipe 12a, and the outer peripheral
surface of the sealing wall portion 122 such as the ring holding
portion 25 faces the inner peripheral surface of the airflow
insertion hole 12b and the inner peripheral surface of the pipe
flange 12c. In this example, the airflow insertion hole 12b is
formed in a circular shape, and the outer peripheral end of the
sealing wall portion 122 is formed in a circular shape in
accordance with the shape of the airflow insertion hole 12b. In
this case, since the separation distance between the outer
peripheral surface of the sealing wall portion 122 and the inner
peripheral surface of the airflow insertion hole 12b is made
uniform, the O-ring 26 can easily secure the airtightness between
the outer peripheral surface and the inner peripheral surface.
[0286] On the other hand, as described above, the sensor SA 50 is
inserted into the internal space 24a defined by the inner
peripheral surface of the housing body 24, and the inner peripheral
surface of the sealing wall portion 122 faces the outer peripheral
surface of the sensor SA 50. In this example, the sensor SA 50 has
a flat cross-sectional shape due to the plate shape of the sensor
SA 50 as a whole, and the inner peripheral end of the sealing wall
portion 122 is formed in a flat shape in accordance with the
cross-sectional shape of the sensor SA 50. The lateral cross
section of the sealing wall portion 122 is a cross section
extending in a direction orthogonal to the height direction Y. The
internal space 24a corresponds to an accommodation space in which
the sensor SA 50 is accommodated.
[0287] As described above, the outer circumference of the sealing
wall portion 122 is circular and the inner circumference of the
sealing wall portion 122 is flat, as a result of which the
thickness dimension D21 of the sealing wall portion 122 is not
uniform in the circumferential direction. A pair of SA plate
surfaces 125, which are a pair of plate surfaces, and a pair of SA
side surfaces 126, which are a pair of side surfaces, are included
in the outer peripheral surface of the sensor SA 50, which is a
plate shape as a whole. The SA plate surface 125 as a whole extends
in the depth direction Z, and the SA side surface 126 as a whole
extends in the width direction X. In the sealing wall portion 122,
a portion of the sensor SA 50 facing the SA plate surface 125 is
thicker as a whole than a portion facing the SA side surface 126.
In this case, in the sealing wall portion 122, a portion having the
largest thickness dimension D21 is included in a portion facing the
SA plate surface 125. The SA plate surface 125 is also a plate
surface extending in the height direction Y in the sensor SA
50.
[0288] The ring holding portion 25 is formed by a holding groove
25a provided in the sealing wall portion 122. In this example, if
the holding groove 25a is formed by a pair of groove defining
portions, the tip end faces of those groove defining portions are
included in the outer peripheral surface of the sealing wall
portion 122. For that reason, the thickness dimension D21 of the
sealing wall portion 122 is a separation distance between the inner
peripheral surface of the sealing wall portion 122 and the tip end
face of the groove defining portion. The pair of groove defining
portions may protrude from the outer peripheral surface of the
sealing wall portion 122. In this case, since the groove defining
portion is not included in the sealing wall portion 122, the
thickness dimension D21 of the sealing wall portion 122 is a
separation distance between the inner peripheral surface of the
sealing wall portion 122 and the bottom surface of the holding
groove 25a. Further, the O-ring 26 is a sealing member which is in
close contact with the sealing wall portion 122 side and the intake
pipe 12a side to restrict the intake air from leaking out of the
airflow insertion hole 12b, and the O-ring 26 can also be referred
to as a packing member. In this case, the ring holding portion 25
corresponds to a sealing holder.
[0289] In the accommodation wall portion 121, both the outer
peripheral end and the inner peripheral end of the lateral cross
section are flattened as a whole. This is because, unlike the
sealing wall portion 122, the outer peripheral surface of the
accommodation wall portion 121 does not face the inner peripheral
surface of the airflow insertion hole 12b, and the shape of the
outer peripheral end of the sealing wall portion 122 does not need
to be matched with the shape of the airflow insertion hole 12b.
Since both the outer peripheral end and the inner peripheral end of
the accommodation wall portion 121 are flattened in this manner,
the thickness dimension D22 of the accommodation wall portion 121
is substantially uniform in the circumferential direction. In other
words, in the accommodation wall portion 121, in order to make the
thickness dimension D22 uniform in the circumferential direction,
the shape of the outer peripheral surface is set in accordance with
the shape of the inner peripheral surface.
[0290] The accommodation wall portion 121 is thinner as a whole
than the sealing wall portion 122. As compared between the wall
thicknesses of the accommodation wall portion 121 and the sealing
wall portion 122, there is a portion in which the sealing wall
portion 122 is thicker than the accommodation wall portion 121, but
there is no portion in which the sealing wall portion 122 is
thinner than the accommodation wall portion 121. In other words,
the thickness dimension D21 of the thickest portion of the sealing
wall portion 122 is larger than the thickness dimension D22 of any
portion of the accommodation wall portion 121, and the thickness
dimension D21 of the thinnest portion of the sealing wall portion
122 is not smaller than the thickness dimension D22 of any portion
of the accommodation wall portion 121.
[0291] The overhanging portion 66a is not only thinner than the
sealing wall portion 122, but also thinner as a whole than the
accommodation wall portion 121. As compared between the wall
thicknesses of the overhanging portion 66a and the accommodation
wall portion 121, there is a portion in which the accommodation
wall portion 121 is thicker than the overhanging portion 66a, but
there is no portion in which the accommodation wall portion 121 is
thinner than the overhanging portion 66a.
[0292] In the housing 21, the region step surface 66 is formed by
an end face of the housing base end side of the accommodation wall
portion 121. As described above, the circuit step surface 55 of the
sensor SA 50 is caught by the region step surface 66, and the
region step surface 66 is held in position in the height direction
Y so as not to move the sensor SA 50 toward the housing because the
region step surface 66 is in contact with the sensor SA 50. The
region step surface 66 is a surface orthogonal to the height
direction Y and corresponds to a third holding portion. The circuit
step surface 55 corresponds to a unit contact portion that is in
contact with the region step surface 66. The region step surface 66
may be referred to as a positioning surface for determining and
obtaining the position of the sensor SA 220.
[0293] The region step surface 66 is also formed by an end face of
the accommodation wall portion 121 on the housing base end side and
a surface of the lateral extending portion 66b on the housing base
end side. For that reason, if the circuit step surface 55 of the
sensor SA 50 is caught by the region step surface 66, the circuit
step surface 55 may touch not only the accommodation wall portion
121 but also the lateral extending portion 66b.
[0294] As described above, the housing body 24 has housing
protrusions 72a and 72b for holding the sensor SA 50 in place
(refer to FIGS. 14 and 15), and the housing protrusions 72a and 72b
are included in the accommodation wall portion 121. As shown in
FIG. 31, the SA side surface 126 of the sensor SA 50 includes
inclined surfaces 126a and 126b that are inclined without being
perpendicular to the depth direction Z. The inclined surfaces 126a
and 126b are included in the outer peripheral surface of the
junction portion 52 of the sensor SA 50. The front inclined surface
126a faces the front side of the sensor SA 50, and the back
inclined surface 126b faces the back side of the sensor SA 50.
[0295] When the width direction X corresponds to a first direction,
the width housing protrusion 72a comes in contact with the SA plate
surface 125, thereby holding the sensor SA 50 in position in the
width direction X and corresponds to a first holding portion. This
is because the SA plate surface 125 is orthogonal to the width
direction X. On the other hand, when the depth direction Z
corresponds to a second direction, the depth housing protrusion 72b
comes in contact with the front inclined surface 126a, thereby
holding the sensor SA 50 in position in both the width direction X
and the depth direction Z, and corresponds to both the first
holding portion and the second holding portion. This is because the
front inclined surface 126a is inclined with respect to both the
width direction X and the depth direction Z.
[0296] In this manner, the sensor SA 50 comes in contact with the
region step surface 66 of the accommodation wall portion 121 and
the housing protrusions 72a and 72b, and is thus held in position
in all of the width direction X, the height direction Y, and the
depth direction Z. In that case, the accommodation wall portion 121
has a first holding portion, a second holding portion, and a third
holding portion, and corresponds to a position holder. At least a
part of the contact portion between the accommodation wall portion
121 and the sensor SA 50 is bonded by bonding using an adhesive or
welding using a molten resin. For example, the region step surface
66 of the accommodation wall portion 121 and the circuit step
surface 55 of the sensor SA 50 are joined to each other, and the
joining portion extends annularly along the peripheral portion of
the sensor SA 50. In that case, since a space between the region
step surface 66 and the circuit step surface 55 is sealed by an
adhesive or molten resin, a thermosetting resin is prevented from
leaking from the sealing region PA through the space between the
region step surface 66 and the circuit step surface 55 when the
potting portion 65 is formed.
[0297] As described above, when the housing 21 is molded with resin
using a molten resin obtained by melting a thermoplastic resin,
unintentional deformation may occur in the housing 21 as the molten
resin is cured. Examples of unintentional deformation include sinks
and sores, and sinks are depressions, cavities, and the like
generated by curing of the molten resin, and sores are deformation
after injection and the like caused by a residual stress or a
residual strain caused by a temperature difference or the like when
the molten resin is cured.
[0298] The unintentional deformation due to the resin molding is
more likely to occur in the thicker portion of the housing 21. For
example, because the sealing wall portion 122 as a whole is thicker
than the accommodation wall portion 121, deformation due to resin
molding is more likely to occur in the sealing wall portion 122
than in the accommodation wall portion 121. For that reason, unlike
the present embodiment, for example, in the configuration in which
the region step surface 66 and the housing protrusions 72a and 72b
are provided on the sealing wall portion 122, the possibility of
unintentional deformation of the region step surface 66 and the
housing protrusions 72a and 72b during resin molding is increased.
In this instance, the positions of the sensor SA 50 and the flow
rate detector 22 are deviated from designed positions due to
unintentional deformation of the region step surface 66 and the
housing protrusions 72a and 72b, and the detection accuracy of the
flow rate detector 22 is lowered.
[0299] On the other hand, since the accommodation wall portion 121
is thinner as a whole than the sealing wall portion 122,
deformation due to resin molding is less likely to occur than the
sealing wall portion 122. Therefore, in the present embodiment, as
described above, the region step surface 66 and the housing
protrusions 72a and 72b are included in the accommodation wall
portion 121 instead of the sealing wall portion 122. In other
words, the region step surface 66 and the housing protrusions 72a
and 72b are provided closer to the housing tip side than the ring
holding portion 25 and the flange portion 27. In that instance, the
positional deviation of the sensor SA 50 and the flow rate detector
22 are less likely to occur due to unintentional deformation due to
resin molding, and the detection accuracy of the flow rate detector
22 is less likely to be lowered.
[0300] Even in the configuration in which the region step surface
66 and the housing protrusions 72a and 72b are included in the
accommodation wall portion 121, it is conceivable that the
deformation caused by the resin molding may occur in the
accommodation wall portion 121 to cause the positional deviations
of the sensor SA 50 and the flow rate detector 22 to occur. For
example, when the position of the sensor SA 50 is deviated so as to
rotate in the width direction X and the depth direction Z with the
contact portions with the region step surface 66 and the housing
protrusions 72a and 72b as fulcrums, the flow rate detector 22 may
deviate in the width direction X and the depth direction Z.
[0301] Therefore, in the sensor SA 50 according to the present
embodiment, in the height direction Y, a separation distance L3
between the flow rate detector 22 and the circuit step surface 55
is smaller than a separation distance L4 between the end portion on
the housing base end side and the circuit step surface 55. In other
words, in the height direction Y, the circuit step surface 55 is
provided at a position closer to the flow rate detector 22. In this
example, when the sensor SA 50 rotates with the contact portion
with the accommodation wall portion 121 as a fulcrum, as a rotation
radius of the flow rate detector 22 is smaller, a positional
deviation amount of the flow rate detector 22 in the width
direction X and the depth direction Z is smaller. As described
above, as the separation distance L3 between the circuit step
surface 55 and the flow rate detector 22 in the height direction Y
is smaller, the positional deviation amount of the flow rate
detector 22 is smaller, and the detection accuracy of the flow rate
detector 22 is less likely to be lowered.
[0302] In the present embodiment, the separation distance between
the center portion of the detection element 22b of the flow rate
detector 22 and the circuit step surface 55 in the height direction
Y is defined as the separation distance L3. However, the separation
distance L3 may be a value indicating the degree of separation
between the flow rate detector 22 and the circuit step surface 55,
and may be, for example, a separation distance between the end
portion of the flow rate detector 22 on the housing base end side
and the circuit step surface 55 in the height direction Y.
[0303] In the internal space 24a of the housing body 24, a volume
V1 of the accommodation region PB1 is smaller than a volume V2 of
the sealing region PA because the separation distance L3 is smaller
than the separation distance L4. In other words, when the volume V1
of the accommodation region PB1 is smaller than the volume V2 of
the sealing region PA, there is a high possibility that the circuit
step surface 55 is provided at a position closer to the flow rate
detector 22 in the height direction Y in the sensor SA 50. Further,
in the internal space 24a, when a region between the region step
surface 66 and the end portion of the sensor SA 50 on the housing
tip side in the height direction Y is referred to as a detection
region PB3 in which the flow rate detector 22 is accommodated, a
volume V3 of the detection region PB3 is smaller than the volume V2
of the sealing region PA. On the other hand, the volume V3 of the
detection region PB3 is larger than the volume V1 of the
accommodation region PB1. The detection region PB3 is a region
including the entire accommodation region PB1 and a portion of the
measurement region PB2 on the housing base end side.
[0304] If any deformation caused by the molding of the resin
slightly occurs in the accommodation wall portion 121, when the
operator inserts the sensor SA 50 into the accommodation wall
portion 121 at the time of manufacturing the air flow meter 14, the
sensor SA 50 may be distorted in accordance with the deformation of
the accommodation wall portion 121. For example, when the upstream
side portion and the downstream side portion of the region step
surface 66 are displaced in the height direction Y, the sensor SA
50 may be distorted such that the upstream side portion and the
downstream side portion of the circuit step surface 55 are
displaced in the height direction Y. If the position of the flow
rate detector 22 deviates from a designed position due to the
distortion of the sensor SA 50, the detection accuracy of the flow
rate detector 22 is likely be lowered.
[0305] Therefore, in the sensor SA 50 of the present embodiment,
the flow rate detector 22 is disposed at a position as far as
possible from the circuit step surface 55. Specifically, in the
height direction Y, the separation distance L3 between the flow
rate detector 22 and the region step surface 66 is larger than the
thickness dimension D22 of the lateral extending portion 66b. In
other words, the flow rate detector 22 is disposed closer to the
housing tip side than the overhanging portion 66a. In that
instance, for example, even if a portion of the sensor SA 50 in the
vicinity of the circuit step surface 55 is distorted due to the
occurrence of the deformation caused by resin molding in the region
step surface 66 of the housing body 24, the distortion is less
likely to reach the flow rate detector 22. For that reason, even if
the deformation due to resin molding occurs in the region step
surface 66 of the accommodation wall portion 121, the flow rate
detector 22 is less likely to be displaced.
[0306] In the sensor SA 50, the SA protrusions 71a and 71b are
provided between the circuit step surface 55 and the flow rate
detector 22 in the height direction Y, and from the above
viewpoint, it is conceivable that the flow rate detector 22 is
disposed as far as possible from the circuit step surface 55. In
particular, the SA protrusions 71a and 71b extend in the height
direction Y, and a spacing dimension between the circuit step
surface 55 and the flow rate detector 22 in the height direction Y
is larger than the longitudinal dimension of the SA protrusions 71a
and 71b. Therefore, even if deformation due to resin molding occurs
in the region step surface 66, the distortion is less likely to
reach the flow rate detector 22 in the sensor SA 50.
[0307] Since the flow rate detector 22 is located as far as
possible from the circuit step surface 55, the flow rate detector
22 is also separated from the ring holding portion 25. In that
case, in the air flow meter 14, even if a heat is applied from the
internal combustion engine 11 or the like to the housing body 24,
the flange portion 27, and the potting portion 65 outside the
intake pipe 12a, the heat is less likely to be transmitted to the
flow rate detector 22. For that reason, the detection accuracy of
the flow rate detector 22 is less likely to be lowered by a heat
from the outside of the intake pipe 12a.
[0308] In the sensor SA 50 of the present embodiment, as shown in
FIG. 29, the flow rate detector 22 is disposed at a position as far
as possible from the accommodation wall portion 121 in the depth
direction Z. Specifically, a separation distance L5 between the
flow rate detector 22 and the accommodation wall portion 121 in the
depth direction Z is larger than the thickness dimension D23 of the
accommodation wall portion 121. The separation distance L5 is
larger than a thickness dimension D23 of the thickest portion of
the accommodation wall portion 121. The flow rate detector 22 is
disposed at the center position of the accommodation region PB1 in
the depth direction Z, and for that reason, the separation distance
L5 is 1/2 of the depth dimension D6 of the accommodation region PB1
in the depth direction Z (refer to FIG. 8). In addition, in a
portion of the accommodation wall portion 121 where the housing
protrusions 72a and 72b are present, the protrusion dimensions of
the housing protrusions 72a and 72b are included in the thickness
dimension D23.
[0309] In that instance, for example, even if a portion of the
sensor SA 50 in the vicinity of the outer peripheral surface of the
junction portion 52 is distorted due to the deformation caused by
the resin molding occurring in the depth housing protrusion 72b of
the accommodation wall portion 121, the distortion is less likely
to reach the flow rate detector 22. For that reason, even if the
deformation due to resin molding occurs in the depth housing
protrusion 72b of the accommodation wall portion 121, the flow rate
detector 22 is hardly displaced.
[0310] In the present embodiment, the separation distance between
the central portion of the flow rate detector 22 and the inner
peripheral surface of the accommodation wall portion 121 in the
depth direction Z is defined as a separation distance L5. However,
the separation distance L5 may be a value indicating the degree of
separation between the flow rate detector 22 and the accommodation
wall portion 121 in the depth direction Z, and may be, for example,
a spacing dimension between the flow rate detector 22 and the
accommodation wall portion 121 in the depth direction Z.
[0311] Next, a manufacturing method of the air flow meter 14 will
be described with reference to FIGS. 14, 29, and 30, focusing on a
process of mounting the sensor SA 50 to the housing 21.
[0312] After the housing 21 has been molded with resin by using the
mold device 90, the sensor SA 50 is inserted into the internal
space 24a through the housing opening 61. When the junction portion
52 of the sensor SA 50 is fitted into the accommodation wall
portion 121, the front SA protrusion 71a deforms the width housing
protrusion 72a, and the junction portion 52 deforms the depth
housing protrusion 72b. When the sensor SA 50 is inserted into the
internal space 24a and the circuit step surface 55 of the sensor SA
50 is pressed against the region step surface 66 of the housing 21,
the insertion of the sensor SA 50 is terminated. The housing
opening 61 corresponds to an accommodation opening for
accommodating the sensor SA 50 in the internal space 24a.
[0313] In that instance, since the tip end face of the width
housing protrusion 72a comes in contact with the tip end face of
the front SA protrusion 71a, the sensor SA 50 is restricted from
moving toward the width housing protrusion 72a in the width
direction X. On the other hand, the sensor SA 50 is prevented from
moving away from the width housing protrusion 72a because the back
SA protrusion 71b of the sensor SA 50 comes in contact with the
inner peripheral surface of the accommodation wall portion 121. In
that case, the tip end face of the width housing protrusion 72a and
a portion of the inner peripheral surface of the accommodation wall
portion 121 which comes in contact with the back SA protrusion 71b
can be referred to as a positioning surface.
[0314] Further, in that instance, since the tip end face of the
depth housing protrusion 72b comes in contact with the upstream
side end face of the junction portion 52, the sensor SA 50 is
restricted from moving toward the depth housing protrusion 72b in
both the width direction X and the depth direction Z. On the other
hand, the sensor SA 50 is restricted from moving away from the
depth housing protrusion 72b because the downstream side surface of
the sensor SA 50 comes in contact with the inner peripheral surface
of the accommodation wall portion 121. In that instance, a portion
of the tip end face of the depth housing protrusion 72b or the
inner peripheral surface of the accommodation wall portion 121,
with which the downstream side end face of the sensor SA 50 comes
in contact may be referred to as a positioning surface.
[0315] Further, since the circuit step surface 55 of the sensor SA
50 comes in contact with the region step surface 66 of the housing
21, the sensor SA 50 is restrained from moving toward the housing
tip side in the height direction Y. On the other hand, the movement
of the sensor SA 50 toward the housing base end side is restricted
by fitting the junction portion 52 of the sensor SA 50 into the
accommodation wall portion 121.
[0316] After the sensor SA 50 has been inserted into the internal
space 24a, a thermosetting resin such as a potting resin is
injected into the internal space 24a, and the thermosetting resin
is cured to form the potting portion 65. In this instance, the
movement of the sensor SA 50 toward the housing base end side is
also restricted by the potting portion 65.
[0317] In the configuration group C, according to the present
embodiment, in the housing 21, the accommodation wall portion 121
is separated from the ring holding portion 25 toward the housing
tip side. For that reason, the ring holding portion 25 can be
thickened to improve the strength, while the accommodation wall
portion 121 can be thinned so as not to be deformed by resin
molding. As described above, since the accommodation wall portion
121 is thinned, the shapes of the accommodation wall portions 121
are less likely to vary from product to product, and therefore, the
position of the sensor SA 50 positioned by the accommodation wall
portion 121 is less likely to vary. Therefore, the detection
accuracy of the flow rate detector 22 can be inhibited from varying
from product to product.
[0318] According to the present embodiment, the housing opening 61
is provided closer to the housing base end side than the region
step surface 66. In this example, there is a concern that the
housing body 24 is unintentionally deformed due to the relatively
low strength of the portion of the housing 21 where the housing
opening 61 is provided. On the other hand, in the housing 21, the
strength of the housing 21 is enhanced by the sealing wall portion
122, the ring holding portion 25, and the flange portion 27 on the
housing base end side of the region step surface 66. Therefore, the
housing opening 61 is provided in a portion of the housing 21 where
the strength on the housing base end side is more easily secured
than the region step surface 66, thereby being capable of
inhibiting unintentional deformation of the housing body 24 due to
the presence of the housing opening 61. As a result, the positional
deviation of the sensor SA 50 caused by the deformation of the
housing body 24 can be inhibited.
[0319] According to the present embodiment, both the width housing
protrusion 72a for regulating the movement of the sensor SA 50 in
the width direction X and the depth housing protrusion 72b for
regulating the movement of the sensor SA 50 in the depth direction
Z are included in the accommodation wall portion 121. In this
instance, since the housing protrusions 72a and 72b of the
accommodation wall portion 121 are less likely to be deformed by
the resin molding, the position of the sensor SA 50 in the width
direction X and the depth direction Z can be inhibited from varying
from product to product.
[0320] According to the present embodiment, a large part of the
inner peripheral surface of the accommodation wall portion 121 does
not come in contact with the outer peripheral surface of the sensor
SA 50, but limited parts such as the tip portions of the housing
protrusions 72a and 72b come in contact with the outer peripheral
surface of the sensor SA 50. In that case, even if the deformation
attributable to the resin molding occurs in the accommodation wall
portion 121, the housing protrusions 72a and 72b are not
necessarily displaced in position or the housing protrusions 72a
and 72b themselves are deformed by the deformation of the
accommodation wall portion 121. For that reason, even if the shape
variation of each product occurs in the accommodation wall portion
121, the position of the sensor SA 50 does not easily vary due to
the deformation variation. This makes it possible to more reliably
inhibit variations in the position of the sensor SA 50 from product
to product.
[0321] According to the present embodiment, the accommodation wall
portion 121 includes the region step surface 66 that restricts the
sensor SA 50 from moving toward the housing tip side in the height
direction Y. In this instance, in the accommodation wall portion
121, since the deformation of the region step surface 66 due to the
resin molding is less likely to be generated, the position of the
sensor SA 50 in the height direction Y can be inhibited from
varying from product to product.
[0322] According to the present embodiment, in the sensor SA 50,
the circuit step surface 55 is provided between the lead terminals
54 and the flow rate detector 22 at a position closer to the flow
rate detector 22. In this instance, even if the sensor SA 50 is
deviated in position so as to rotate about the contact portion with
the region step surface 66 as a fulcrum, the amount of positional
deviation of the flow rate detector 22 can be reduced as compared
with a configuration in which the circuit step surface 55 is
provided at a position closer to the lead terminals 54, for
example. For that reason, the deterioration of the detection
accuracy of the flow rate detector 22 can be inhibited.
[0323] According to the present embodiment, since the ring holding
portion 25 and the accommodation wall portion 121 are connected to
each other by the overhanging portion 66a, a configuration can be
realized in which the accommodation wall portion 121 is separated
from the ring holding portion 25 toward the housing tip side. In
that case, even if the deformation caused by the resin molding
occurs in the ring holding portion 25, the deformation is absorbed
by the overhanging portion 66a, so that the position and the shape
of the accommodation wall portion 121 are less likely to change
with the deformation of the ring holding portion 25. For that
reason, the positioning accuracy of the sensor SA 50 by the region
step surface 66 and the housing protrusions 72a and 72b can be
inhibited from being deteriorated.
[0324] According to the present embodiment, since the separation
distance L3 between the flow rate detector 22 and the region step
surface 66 is larger than the thickness dimension D22 of the
lateral extending portion 66b, a configuration can be realized in
which the flow rate detector 22 is moved away as far as possible
from the region step surface 66 in the height direction Y.
According to the above configuration, even if the deformation
caused by the resin molding is generated in the region step surface
66, the distortion generated in the sensor SA 50 by fitting the
sensor SA 50 inside the accommodation wall portion 121 is less
likely to reach the flow rate detector 22. For that reason, even if
the sensor SA 50 is distorted when the sensor SA 50 is assembled to
the housing 21, the positional deviation of the flow rate detector
22 can be inhibited.
[0325] According to the present embodiment, since the separation
distance L5 between the flow rate detector 22 and the accommodation
wall portion 121 is larger than the thickness dimension D23 of the
accommodation wall portion 121, a configuration can be realized in
which the flow rate detector 22 is moved away as far as possible
from the accommodation wall portion 121 in the depth direction Z.
According to the above configuration, even if the housing
protrusions 72a and 72b are deformed due to the resin molding, the
distortion generated in the sensor SA 50 is less likely to reach
the flow rate detector 22 by fitting the housing protrusions 72a
and 72b inside the accommodation wall portion 121. This makes it
possible to inhibit the positional deviation of the flow rate
detector 22 from occurring due to the distortion of the sensor SA
50.
[0326] According to the present embodiment, the sensor SA 50 is
inserted into the internal space 24a through the housing opening
61. As described above, even when the sensor SA 50 is added to the
resin-molded housing 21 later, the positioning accuracy of the
sensor SA 50 by the accommodation wall portion 121 can be enhanced
because the deformation due to the resin molding is less likely to
be generated in the accommodation wall portion 121.
[0327] <Description of Configuration Group D>
[0328] A configuration group D relating to the configuration of the
passage flow channel will be described with reference to FIGS. 32,
33, and the like.
[0329] As shown in FIG. 32, the passage flow channel 31 does not
extend downstream of the flow channel boundary portion 34 in the
depth direction Z. In other words, in the passage flow channel 31,
a portion between the flow channel boundary portion 34 and the
inflow port 33a in the depth direction Z is the inflow passage 31a,
and there is no portion between the flow channel boundary portion
34 and the outflow port 33b in the depth direction Z. In that case,
a part of the flow channel boundary portion 34 and a part of the
outflow port 33b overlap with each other, and the flow channel
boundary portion 34 extends from the outflow port 33b toward the
inflow port 33a in the depth direction Z. The flow channel boundary
portion 34 corresponds to a branch boundary.
[0330] The inner peripheral surface of the passage flow channel 31
has a passage ceiling surface 151, a passage floor surface 152, and
a passage wall surface 153. The passage ceiling surface 151 and the
passage floor surface 152 are opposed to each other across the
passage flow channel 31 in the height direction Y, and the passage
ceiling surface 151 is disposed closer to the housing base end side
than the passage flow channel 31. The passage ceiling surface 151
faces the housing tip side, and the passage floor surface 152 faces
the housing base end side. The pair of passage wall surfaces 153
are provided across the passage ceiling surface 151 and the passage
floor surface 152 in the width direction X, and those passage wall
surfaces 153 are opposed to each other in a state of being directed
in the width direction X.
[0331] The inner peripheral surface of the passage flow channel 31
has throttle surfaces 152a and 153a that throttle the passage flow
channel 31 from the inflow port 33a toward the outflow port 33b. In
that case, the flow channel area of the passage flow channel 31
gradually decreases toward the outflow port 33b. The throttle
surfaces 152a and 153a are included in the inner peripheral surface
of the outflow passage 31b, and extend from the outflow port 33b
toward the inflow passage 31a. The throttle surfaces 152a and 153a
are inclined with respect to the depth direction by being directed
toward the inflow port 33a side. The throttle surfaces 152a and
153a extend over the upstream end portion and the downstream end
portion of the outflow passage 31b, and are not included in the
inner peripheral surface of the inflow passage 31a. The flow path
cross section of the passage flow channel 31 is smaller in the
portion closer to the outflow port 33b in the outflow passage
31b.
[0332] The floor throttle surface 152a is included in the passage
floor surface 152, and the wall throttle surface 153a is included
in the passage wall surface 153. The floor throttle surface 152a is
an inner peripheral surface of a portion of the housing bottom
portion 62 which is inclined with respect to the depth direction Z.
The wall throttle surface 153a is an inner peripheral surface of
the passage throttle portion 47, and a pair of the wall throttle
surfaces 153a are provided across the floor throttle surface 152a
in the width direction X. The floor throttle surface 152a and the
wall throttle surface 153a correspond to a passage throttle
surface.
[0333] The flow channel boundary portion 34 is inclined with
respect to the depth direction Z by being directed toward the
outflow port 33b. In other words, the flow channel boundary portion
34 is inclined with respect to the passage ceiling surface 151. The
flow channel boundary portion 34 faces the floor throttle surface
152a across the outflow port 33b, and extends in parallel with the
floor throttle surface 152a.
[0334] The outer peripheral surface of the housing 21 includes an
eaves surface 154 extending toward the outer peripheral side from
an overlapping portion of the inflow port 33a and the flow channel
boundary portion 34. The eaves surface 154 is disposed on the
opposite side of the passage ceiling surface 151 across the flow
channel boundary portion 34 in the depth direction Z, and extends
in the depth direction Z similarly to the passage ceiling surface
151. For that reason, the floor throttle surface 152a is also
inclined with respect to the eaves surface 154. The eaves surface
154 does not define the passage flow channel 31 because the passage
wall surface 153 is not connected to the eaves surface 154.
[0335] Next, the passage mold portion 104 of the mold device 90
will be described.
[0336] As shown in FIGS. 32 and 33, the outer peripheral surface of
the passage mold portion 104 has a floor throttle molding surface
156 for molding the floor throttle surface 152a and a wall throttle
molding surface 157 for molding the wall throttle surface 153a. The
passage mold portion 104 has an outer passage surface 158 that
abuts against the outer peripheral mold portions 102 and 103 in an
assembled state of the mold device 90, and the outer passage
surface 158 is a tip portion or a tip end face of the passage mold
portion 104. The floor throttle molding surface 156 and the wall
throttle molding surface 157 extend in the depth direction Z from
the outer passage surface 158 of the passage mold portion 104. With
the provision of the molding surfaces 156 and 157, the passage mold
portion 104 is thinner in a portion closer to the outer passage
surface 158. A pair of the wall throttle molding surfaces 157 are
provided across the floor throttle molding surface 156 in the width
direction X. The floor throttle molding surface 156 and the wall
throttle molding surface 157 correspond to a mold throttle
portion.
[0337] The outer peripheral surface of the passage mold portion 104
has an inner passage surface 159 that abuts against the
introduction molding portion 97b in a state in which the mold
device 90 is assembled. The inner passage surface 159 is disposed
on the opposite side of the passage mold portion 104 across the
wall throttle molding surface 157 and the outer passage surface
158, and is perpendicular to the outer passage surface 158. The
floor throttle molding surface 156 is inclined with respect to the
inner passage surface 159. As described above, the introduction
molding portion 97b is included in the measurement molding portion
97, and the measurement molding portion 97 is included in the inner
peripheral mold portion 91. The inner peripheral mold portion 91
corresponds to a measurement mold portion and a branch mold portion
for molding the inner peripheral surface of the measurement flow
channel 32.
[0338] In the assembled state of the mold device 90, the
measurement molding portion 97 abuts against both the passage mold
portion 104 and the outer peripheral mold portions 102 and 103. The
outer peripheral surface of the measurement molding portion 97 has
an outer measurement surface 161 that abuts against the outer
peripheral mold portions 102 and 103 in the mold device 90, and an
inner measurement surface 162 that abuts against the inner passage
surface 159 of the passage mold portion 104. Before the mold device
90 is removed from the resin-molded housing 21, the outer
measurement surface 161 and the inner measurement surface 162 are
disposed inside the passage flow channel 31 because the tip portion
of the measurement molding portion 97 enters the passage flow
channel 31. In that case, the outer passage surface 158 of the
passage mold portion 104 and the outer measurement surface 161 of
the measurement molding portion 97 form the same plane, and the
plane is included in the outflow port 33b. In the measurement
molding portion 97, a portion entering the passage flow channel 31
is referred to as an entry portion 163, and the entry portion 163
is indicated by dot hatching in FIG. 32.
[0339] When a portion of the measurement molding portion 97
abutting against the first outer peripheral mold portion 102 will
be described with reference to an illustration of FIG. 33, the mold
device 90, is formed with a mold boundary 165, which is a boundary
between the measurement molding portion 97, the passage mold
portion 104, and the first outer peripheral mold portion 102. The
mold boundary 165 extends in the width direction X, and the mold
boundary 165 includes a boundary between the outer measurement
surface 161 and the inner measurement surface 162 of the
measurement molding portion 97. The mold boundary 165 is disposed
at the outflow port 33b of the passage flow channel 31 in the
housing 21. In a portion of the measurement molding portion 97
abutting against the second outer peripheral mold portion 103, a
boundary of three mold portions, that is, the measurement molding
portion 97, the passage mold portion 104, and the second outer
peripheral mold portion 103, may be referred to as a mold boundary
165.
[0340] As described above, when the mold device 90 is detached from
the resin-molded housing 21, after the passage mold portion 104 is
extracted from the inflow port 33a of the housing 21, the outer
peripheral mold portions 102 and 103 are detached from the outer
peripheral surface of the housing 21. Either the operation of
detaching the inner peripheral mold portion 91 from the housing 21
or the operation of detaching the passage mold portion 104 from the
housing 21 may be performed first.
[0341] In the configuration group D, according to the present
embodiment, the inner peripheral surface of the passage flow
channel 31 is integrally molded by using the mold device 90 at the
time of molding the housing 21 with resin. For that reason, there
is no need to provide the passage flow channel 31 by separately
molding multiple members with resin and then combining those
members together. In that case, it is difficult to generate a step
on the inner peripheral surface of the passage flow channel 31 at
the boundary between the members, or to cause the shape and size of
the passage flow channel 31 to vary from product to product. With a
reduction in the manufacturing variation in this manner, the
detection accuracy of the flow rate detector 22 can be
enhanced.
[0342] According to the present embodiment, when the mold device 90
is detached from the resin-molded housing 21, after the passage
mold portion 104 has been extracted from the inflow port 33a of the
housing 21, the outer peripheral mold portions 102 and 103 are
detached from the outer peripheral surface of the housing 21. In
this case, when the passage mold portion 104 is extracted from the
inflow port 33a in the depth direction Z, the outer peripheral
portion of the housing 21 is protected by the outer peripheral mold
portions 102 and 103. For that reason, even if the passage mold
portion 104 is extracted from the inflow port 33a while being
twisted so that the tip portion of the passage mold portion 104 is
swung in the width direction X and the height direction Y, the
housing 21 is less likely to be deformed from the inner peripheral
side by the passage mold portion 104. This makes it possible to
inhibit the housing 21 from being deformed or damaged
unintentionally when the passage mold portion 104 is detached from
the housing 21.
[0343] According to the present embodiment, before the mold device
90 is removed from the resin-molded housing 21, the entry portion
163 of the measurement molding portion 97 enters the passage flow
channel 31. In other words, the mold boundary 165 is formed inside
the passage flow channel 31. In this manner, a part of the inner
peripheral surface of the passage flow channel 31 is molded by the
measurement molding portion 97, in the mold device 90 in which the
passage mold portion 104 is not extracted from the outflow port
33b, the degree of freedom of design and manufacturing relating to
the shape of the passage flow channel 31 can be enhanced. For that
reason, the housing 21 in which the flow channel boundary portion
34 faces the outflow port 33b side can be realized as in the
present embodiment.
[0344] According to the present embodiment, the passage mold
portion 104 gradually tapers toward the tip portion forming the
outer passage surface 158. In other words, the passage mold portion
104 has a shape that does not become thicker. For that reason, when
the housing 21 is molded with resin in a state in which the passage
mold portion 104 and the outer peripheral mold portions 102 and 103
are assembled to each other, the passage mold portion 104 can be
pulled out from the inflow port 33a of the housing 21 toward the
side opposite to the outer passage surface 158. In this case, the
inner peripheral surface of the passage flow channel 31 can be
integrally molded by using the passage mold portion 104.
[0345] According to the present embodiment, since the floor
throttle molding surface 156 and the wall throttle molding surface
157 are included in the outer peripheral surface of the passage
mold portion 104, a shape can be realized in which the passage mold
portion 104 gradually narrows toward the outer passage surface 158.
In this case, in the inner peripheral surface of the passage flow
channel 31, an area of a portion of the passage mold portion 104
extending in parallel to the depth direction Z, which is a drawing
direction of the passage mold portion 104, is reduced by an amount
corresponding to the floor throttle molding surface 156 and the
wall throttle molding surface 157. For that reason, the passage
mold portion 104 can be easily pulled out from the inside of the
passage flow channel 31.
[0346] According to the present embodiment, in the depth direction
Z, the passage flow channel 31 is not narrowed from the outflow
port 33b toward the inflow port 33a. In that case, since the
passage mold portion 104 can be extracted from the inflow port 33a
when the housing 21 is molded with resin using the mold device 90,
there is no need to define the passage flow channel 31 by combining
multiple members. Unlike the present embodiment, for example, in
the configuration in which the intermediate portion of the passage
flow channel 31 is the thickest, it is difficult to extract the
passage mold portion 104 from the inflow port 33a due to the
passage mold portion 104 being caught on the inner peripheral
surface of the passage flow channel 31. In the above configuration,
since the passage flow channel 31 is defined by combining multiple
members together, the manufacturing variation of the passage flow
channel 31 as described above is likely to occur.
[0347] According to the present embodiment, since the floor
throttle surface 152a and the wall throttle surface 153a are
included in the inner peripheral surface of the passage flow
channel 31, the degree of throttling of the passage flow channel 31
can be increased toward the outflow port 33b. In addition, since
the floor throttle surface 152a and the wall throttle surface 153a
extend from the outflow port 33b toward the inflow port 33a, the
degree of throttling of the outflow port 33b can be maximized in
the passage flow channel 31. As a result, even in the configuration
in which the outflow port 33b extends from the flow channel
boundary portion 34, a flow velocity of the air in the measurement
flow channel 32 can be appropriately increased by narrowing the
outflow port 33b.
[0348] According to the present embodiment, since the outflow port
33b extends from the flow channel boundary portion 34, there is no
need to extend the passage mold portion 104 to the outflow port 33b
side of the flow channel boundary portion 34 when molding the
housing 21 with resin. In that case, a portion of the passage flow
channel 31 which is aligned with the flow channel boundary portion
34 in the height direction Y can be molded not only by the passage
mold portion 104 but also by the measurement molding portion 97.
For that reason, when the housing 21 is formed using the mold
device 90 in which the passage mold portion 104 is not extracted
from the outflow port 33b, the degree of freedom of design and
manufacturing relating to the positional relationship between the
flow channel boundary portion 34 and the outflow port 33b can be
increased.
[0349] According to the present embodiment, since the flow channel
boundary portion 34 extends from the outflow port 33b, in the
configuration in which the inner peripheral surface of the passage
flow channel 31 is integrally molded, the flow channel boundary
portion 34 can be inclined with respect to the depth direction Z so
as to face the outflow port 33b side. In that case, a foreign
matter that has entered the passage flow channel 31 from the inflow
port 33a cannot reach the flow channel boundary portion 34 only by
advancing straight toward the outflow port 33b. This makes it
possible to inhibit the foreign matter from entering the
measurement flow channel 32 from the passage flow channel 31.
[0350] <Configuration Group E>
[0351] A configuration group E relating to the position of the
connector terminals will be described with reference to FIGS. 34 to
39 and the like. In FIG. 34, the SA protrusions 71a and 71b, the
width housing protrusion 72a, and the terminal fixing portion 87
are omitted, and in FIG. 35, the potting portion 65 is omitted.
[0352] As shown in FIG. 34, the connector portion 28 of the air
flow meter 14 has a connector recess portion 171 in which a tip end
face of the connector portion 28 is recessed. When an open end of
the connector recess portion 171 is referred to as a connector
opening 171a, the connector opening 171a opens an internal space of
the connector recess portion 171 in the depth direction Z. In the
present embodiment, the height direction Y corresponds to a
direction in which the detection unit and the housing opening are
aligned. The connector opening 171a may open the internal space of
the connector recess portion 171 in the width direction X or the
height direction Y.
[0353] The connector terminal 28a extends between the connector
recess portion 171 and the internal space 24a. The connector
terminal 28a has a first terminal portion 172a disposed inside the
connector recess portion 171, a second terminal portion 172b
disposed in the internal space 24a, and a connection terminal
portion 172c connecting the terminal portions 172a and 172b. In the
connector terminal 28a, one end portion is included in the first
terminal portion 172a, and the other end portion is included in the
second terminal portion 172b. The first terminal portion 172a
extends toward the connector opening 171a inside the connector
recess portion 171. The second terminal portion 172b extends toward
the housing opening 61 in the internal space 24a, but does not
protrude outward from the housing opening 61.
[0354] In the connector terminals 28a, a portion protruding from
the inner peripheral surface of the housing 21 into the connector
recess portion 171 is the first terminal portion 172a, and a
portion protruding from the inner peripheral surface of the housing
21 into the internal space 24a is the second terminal portion 172b.
For that reason, the entire connection terminal portion 172c is
buried in the housing 21 between the internal space 24a and the
connector recess portion 171. At least a part of the connection
terminal portion 172c may be embedded in the housing 21. Even in
this case, a configuration in which the connection terminal portion
172c is fixed to the housing 21 can be realized.
[0355] In the sensor SA 50, a portion including the circuit
accommodation portion 51, the junction portion 52, and the sensing
portion 53 is referred to as an SA main body 170, and the SA main
body 170 includes the flow rate detector 22. The lead terminal 54
extends from the SA main body 170 toward the housing opening 61 in
the height direction Y, but does not protrude outward from the
housing opening 61. The SA main body 170 corresponds to a unit main
body.
[0356] The internal space 24a has a main body region PC1 in which
the SA main body 170 is accommodated, and a connector region PC2 in
which the second terminal portion 172b of the connector terminals
28a is accommodated. The main body region PC1 and the connector
region PC2 are aligned laterally in the width direction X, which is
a direction perpendicular to the height direction Y, and both of
the main body region PC1 and the connector region PC2 extend from
the housing opening 61 toward the housing tip side. The main body
region PC1 includes a region that extends over the region step
surface 66 and the housing opening 61 in the height direction Y,
and the connector region PC2 is a region that extends over the
sealing step surface 67 and the housing opening 61 in the height
direction Y. In the width direction X, which is a direction
perpendicular to the height direction Y, a boundary between the
region step surface 66 and the sealing step surface 67 is included
in a boundary between the main body region PC1 and the connector
region PC2. A pair of the region step surfaces 66 is provided
across the internal space 24a in the width direction X.
[0357] The connector region PC2 is disposed at a position spaced
apart from the SA main body 170 toward the housing opening 61 in
the height direction Y. This is because the sealing step surface 67
is disposed between the housing opening 61 and the SA main body 170
in the height direction Y.
[0358] In the connector region PC2, the second terminal portion
172b of the connector terminal 28a extends from the sealing step
surface 67 toward the housing opening 61. In the connector terminal
28a, the connection terminal portion 172c is not exposed to the
connector region PC2. In this instance, a part of a portion
extending from the connection terminal portion 172c toward the
housing opening 61, which is disposed in the connector region PC2,
forms the second terminal portion 172b. The second terminal portion
172b corresponds to a protrusion terminal portion and a
longitudinal terminal portion.
[0359] In the internal space 24a, the connector terminal 28a is not
inserted between the housing opening 61 and the sensor SA 50 in the
height direction Y. This is because the second terminal portion
172b does not protrude from the connector region PC2 to the main
body region PC1. In other words, the connector terminal 28a does
not protrude into the main body region PC1.
[0360] In the internal space 24a, the circuit step surface 55 of
the sensor SA 50 is caught by the region step surface 66 from the
housing opening 61. The bridge terminal 86 of the terminal unit 85
is caught by the sealing step surface 67 from the housing opening
61 side. As described above, both the region step surface 66 and
the sealing step surface 67 are included in the inner peripheral
surface of the housing 21. The region step surface 66 corresponds
to a unit holding surface that holds the position of the sensor SA
50 in the height direction Y, and the sealing step surface 67
corresponds to a terminal holding surface that holds the position
of the bridge terminal 86 in the height direction Y. The bridge
terminal 86 corresponds to a connection terminal.
[0361] The bridge terminal 86 has a first bridge portion 173a
connected to the lead terminal 54, a second bridge portion 173b
connected to the connector terminals 28a, and a connection bridge
portion 173c connected to the bridge portions 173a and 173b. The
bridge terminal 86 extends across the boundary between the main
body region PC1 and the connector region PC2 in the width
directions X. The first bridge portion 173a extends along the lead
terminal 54 in the main body region PC1, and the second bridge
portion 173b extends along the second terminal portion 172b of the
connector terminals 28a in the connector region PC2. The connection
bridge portion 173c is bridged between the main body region PC1 and
the connector region PC2.
[0362] The second bridge portion 173b enters between the sealing
step surface 67 and the housing opening 61, and at least one of the
second bridge portion 173b and the connection bridge portion 173c
comes in contact with the sealing step surface 67. In this case,
the sealing step surface 67 supports the connection portion between
the second bridge portion 173b and the second terminal portion
172b. The first bridge portion 173a includes a second connection
portion 86b (refer to FIG. 18, and so on), and a portion including
the second connection portion 86b is a connection portion between
the first bridge portion 173a and the lead terminal 54. The second
bridge portion 173b includes a first connection portion 86a (refer
to FIG. 18, and so on), and a portion including the first
connection portion 86a is a connection portion between the second
bridge portion 173b and the second terminal portion 172b.
[0363] As shown in FIG. 35, the multiple lead terminals 54 included
in the sensor SA 50 include a terminal electrically connected to
the intake air temperature terminal 23c in addition to a terminal
electrically connected to the connector terminal 28a. Like the
connector terminal 28a, the intake air temperature terminal 23c is
also connected to the lead terminal 54 through the bridge terminal
86. Like the second terminal portion 172b of the connector
terminals 28a, the intake air temperature terminals 23c has an
intake air temperature terminal portion 175 protruding from the
sealing step surface 67 to the connector region PC2 and extending
toward the housing opening 61. In this instance, the intake air
temperature terminal portion 175 is also disposed in the connector
region PC2 so as not to protrude into the main body region PC1,
similarly to the second terminal portion 172b.
[0364] Next, the mold device 90 will be described with reference to
FIGS. 22 and 36. FIG. 36 illustrates the mold device 90 when the
outer peripheral surface of the second outer peripheral mold
portion 103 is viewed from the side opposite to the first outer
peripheral mold portion 102.
[0365] As shown in FIGS. 22 and 36, the mold device 90 has a
connector mold portion 177 which is assembled to the inner
peripheral mold portion 91 and the second outer peripheral mold
portion 103. The connector mold portion 177 is assembled to the
outer peripheral surface of the second outer peripheral mold
portion 103 in a state of being inserted into the inner peripheral
mold portion 91, thereby molding the inner peripheral surface of
the connector portion 28. The connector mold portion 177 according
to the present embodiment is formed as a separate member from the
inner peripheral mold portion 91 and the second outer peripheral
mold portion 103. The connector mold portion 177 may be integrally
attached to the inner peripheral mold portion 91 or the second
outer peripheral mold portion 103, and in this case, the connector
mold portion 177 is included in the inner peripheral mold portion
91 or the second outer peripheral mold portion 103.
[0366] In the assembled state of the mold device 90, the connector
terminal 28a and the intake air temperature terminal 23c are
already mounted on the mold device 90. The mold device 90 has a
temporary support portion 178 for temporarily supporting the
connector terminal 28a and the intake air temperature terminal 23c,
and the connector terminal 28a and the intake air temperature
terminal 23c can be temporarily attached to the temporary support
portion 178. The temporary support portion 178 is included in, for
example, the connector mold portion 177, and the connector
terminals 28a and the intake air temperature terminal 23c can be
detachably attached. The temporary support portion 178 can
transition to a support state capable of supporting the terminals
28a and 23c and a releasing state for releasing the support of the
terminals 28a and 23c.
[0367] In the mold device 90, the connector terminal 28a is
accommodated inside the connector mold portion 177, while the
intake air temperature terminal 23c is in a state of being extended
over the connector mold portion 177, the second outer peripheral
mold portion 103, and the root mold portions 105 and 106.
[0368] Next, a manufacturing method of the air flow meter 14 will
be described with reference to FIGS. 36 to 39, and so on, focusing
on a procedure after the housing 21 has been molded with resin.
[0369] In the present embodiment, insert molding is performed by
resin molding the housing in which the connector terminal 28a and
the intake air temperature terminal 23c are embedded. In the insert
molding, in a process of assembling the mold device 90, as shown in
FIG. 36, the connector terminal 28a and the intake air temperature
terminal 23c are temporarily attached to the temporary support
portion 178 of the connector mold portion 177. Then, the connector
mold portion 177 in this state is assembled to the inner peripheral
mold portion 91, the outer peripheral mold portions 102, 103, and
the like. Thereafter, a molten resin is injected into the mold
device 90, the molten resin is cured to mold the housing 21, and
then the mold device 90 is removed from the housing 21.
[0370] In this step, the connector terminal 28a and the intake air
temperature terminal 23c are detached from the temporary support
portion 178 by shifting the temporary support portion 178 to the
released state, and the connector mold portion 177 is detached from
the connector portion 28 of the housing 21. In addition, the inner
peripheral mold portion 91 and the outer peripheral mold portions
102 and 103 are also removed from the housing 21. In the
resin-molded housing 21, a part of each of the connector terminal
28a and the intake air temperature terminal 23c is embedded in the
housing 21.
[0371] Then, as shown in FIG. 37, a step of installing the sensor
SA 50 in the internal space 24a of the housing 21 is performed. In
this step, the sensor SA 50 is inserted into the main body region
PC1 of the internal space 24a from the housing opening 61, and the
sensor SA 50 is pushed in until the circuit step surface 55 of the
sensor SA 50 is caught by the region step surface 66 of the housing
21. With the insertion of the lead terminal 54 into the housing
opening 61 from the sensing portion 53 of the sensor SA 50, the
lead terminal 54 is disposed in the sealing region PA of the
internal space 24a.
[0372] In the mold device 90, the housing 21 is resin-molded so
that the entire connection terminal portion 172c of the connector
terminal 28a is embedded in the housing 21. For that reason, in the
configuration in which the inner peripheral surfaces of the main
body region PC1 and the connector region PC2 are molded by the
inward portion 93 of the inner peripheral mold portion 91, the main
body region PC1 and the connector region PC2 can be molded by
simply pulling out the inward portion 93 from the housing opening
61.
[0373] Unlike the present embodiment, for example, in order to
resin-mold the housing 21 in which the connection terminal portion
172c is separated from the sealing step surface 67 toward the
housing opening 61, there is a need to make a part of the inward
portion 93 go around between the connection terminal portion 172c
and the sealing step surface 67. In this configuration, since it
becomes difficult to remove the inward portion 93 from the housing
opening 61, the housing 21 is not integrally molded, but multiple
members must be assembled together and manufactured.
[0374] As described above, the second terminal portion 172b and the
intake air temperature terminal portion 175 of the connector
terminal 28a are installed in the connector region PC2 so as not to
protrude into the main body region PC1. For that reason, when the
sensor SA 50 is inserted into the main body region PC1, the sensor
SA 50 is less likely to come into contact with the second terminal
portion 172b and the intake air temperature terminal portion 175.
In the main body region PC1, the region step surface 66 faces the
housing opening 61. For that reason, the operator can easily
install the sensor SA 50 in the main body region PC1 so as not to
come in contact with the second terminal portion 172b and the
intake air temperature terminal portion 175 by inserting the sensor
SA 50 aiming at a space between the pair of region step surfaces
66.
[0375] Thereafter, as shown in FIG. 38, the terminal unit 85 is
inserted into the internal space 24a from the housing opening 61
and pushed between the lead terminal 54 and the second terminal
portion 172b of the connector terminal 28a. In this example, the
bridge terminal 86 is temporarily attached to the housing 21 by
bringing the bridge terminal 86 in contact with the sealing step
surface 67.
[0376] The operation of joining the bridge terminal 86 to each of
the lead terminal 54 and the connector terminal 28a by welding or
the like is performed using a joining tool such as a welding device
having a pair of welding electrodes. In this example, a pair of
welding electrodes are inserted into the internal space 24a from
the housing opening 61, and the lead terminal 54 and the first
bridge portion 173a are sandwiched between the welding electrodes
to perform welding between the lead terminal 54 and the first
bridge portion 173a. With the above joining operation, a connection
portion between the lead terminal 54 and the bridge terminal 86 is
formed. The second terminal portion 172b and the second bridge
portion 173b are welded by sandwiching the second terminal portion
172b and the second bridge portion 173b with a pair of welding
electrodes. With the above joining operation, a connection portion
between the connector terminals 28a and the bridge terminals 86 is
formed.
[0377] In FIG. 39, after the operation of electrically connecting
the lead terminal 54 and the connector terminal 28a through the
bridge terminal 86 has been completed, a thermosetting resin such
as potting resin is injected from the housing opening 61 into the
sealing region PA of the internal space 24a. Then, the potting
portion 65 is formed by applying a heat to the thermosetting resin
and curing the thermosetting resin. In this example, not only the
SA main body 170 is covered with the thermosetting resin, but also
the lead terminal 54, the bridge terminal 86, and the connector
terminal 28a are covered with the thermosetting resin. In this
case, the connection portion between the lead terminal 54 and the
bridge terminal 86 and the connection portion between the bridge
terminal 86 and the connector terminal 28a are protected by the
potting portion 65.
[0378] In the configuration group E, according to the present
embodiment, in the internal space 24a of the housing 21, the
connector terminal 28a does not enter between the housing opening
61 and the sensor SA 50 in the height direction Y. For that reason,
after the connector terminal 28a has been attached to the housing
21, the sensor SA 50 can be inserted into the internal space 24a
through the housing opening 61. This eliminates a need for
attaching the connector terminal 28a to the housing 21 after the
sensor SA 50 has been installed in the internal space 24a. For that
reason, the sensor SA 50 can be inhibited from being positionally
deviated due to an impact or the like caused by the attachment of
the connector terminal 28a to the housing 21.
[0379] In this example, when the positional deviation of the sensor
SA 50 occurs in the internal space 24a, the position of the flow
rate detector 22 in the measurement flow channel 32 is also
unintentionally deviated. In this case, the detection accuracy of
the flow rate detector 22 is likely to be lowered because the
amount and speed of the intake air flowing along the flow rate
detector 22 in the measurement flow channel 32 deviate from design
values. On the other hand, according to the present embodiment,
since an unintended positional deviation of the sensor SA 50 is
less likely to occur as described above, the detection accuracy of
the flow rate detector 22 can be inhibited from varying from
product to product.
[0380] According to the present embodiment, in the internal space
24a, the second terminal portion 172b of the connector terminal 28a
is accommodated in the connector region PC2 without protruding into
the main body region PC1. For that reason, a configuration can be
realized in which the second terminal portion 172b is not inserted
between the housing opening 61 and the sensor SA 50 in the height
direction Y. When the sensor SA 50 is inserted from the housing
opening 61 into the main body region PC1, the operator simply
prevents the sensor SA 50 from entering the connector region PC2,
thereby being capable of preventing the sensor SA 50 from coming in
contact with the second terminal portion 172b. This makes it
possible to inhibit the sensor SA 50 and the connector terminal 28a
from being damaged or deformed by contacting each other with the
attachment of the sensor SA 50 to the housing 21.
[0381] According to the present embodiment, the connector region
PC2 is disposed at a position closer to the housing opening 61 than
the SA main body 170 of the sensor SA 50. Accordingly, the second
terminal portion 172b of the connector terminal 28a is also
disposed at a position closer to the housing opening 61 than the SA
main body 170. In that case, since there is a need to insert a
joining tool for joining the second terminal portion 172b and the
bridge terminal 86 deeply into the internal space 24a, a work load
for joining can be reduced. Further, as compared with a
configuration in which the joining tool is inserted deeply into the
internal space 24a, the SA main body 170 and the housing 21 can be
inhibited from being damaged or deformed due to a contact of the
joining tool with the SA main body 170 or the housing 21.
[0382] According to the present embodiment, in the internal space
24a, the second terminal portion 172b of the connector terminal 28a
is supported by the sealing step surface 67 from the side opposite
to the housing opening 61. In this case, when the second terminal
portion 172b and the second bridge portion 173b are joined to each
other, unintentional displacement of the second terminal portion
172b is less likely to occur. This makes it possible to inhibit
that the second terminal portion 172b is relatively displaced with
respect to the second bridge portion 173b during the joining
operation, which makes it difficult to properly join the second
terminal portion 172b and the second bridge portion 173b.
[0383] According to the present embodiment, the bridge terminal 86
is supported by the sealing step surface 67 from the side opposite
to the housing opening 61. In this case, when the bridge terminal
86 is temporarily attached to the housing 21, a state in which the
bridge terminal 86 is held in position can be created. For that
reason, when the bridge terminals 86 is joined to the lead terminal
54 and the connector terminal 28a, the work load can be reduced by
an amount that the work of holding the bridge terminals 86 in
position is not required.
[0384] According to the present embodiment, on the inner peripheral
surface of the housing 21, the sealing step surface 67 that
supports the second terminal portion 172b of the connector terminal
28a is disposed at a position closer to the housing opening 61 than
the region step surface 66 that supports the sensor SA 50. In that
case, since the protrusion dimension of the second terminal portion
172b from the sealing step surface 67 becomes as small as possible,
the second terminal portion 172b is less likely to be
unintentionally deformed when the housing 21 is molded with resin
or the like. In that case, since the joint portion between the
connector terminal 28a and the bridge terminal 86 is disposed
between the sealing step surface 67 and the housing opening 61,
there is no need to insert the joining tool to a position deeper
than the sealing step surface 67 in the internal space 24a. For
that reason, the joining operation can be facilitated and the
breakage and deformation of the SA main body 170 and the housing 21
caused by the contact with the joining tool can be realized.
[0385] According to the present embodiment, the second terminal
portion 172b extends from the sealing step surface 67 toward the
housing opening 61. In this case, when the second terminal portion
172b and the second bridge portion 173b are sandwiched between the
bonding tool such as the welding electrodes, there is no need to
insert the joining tool into the back side of the second terminal
portion 172b and the second bridge portion 173b when viewed from
the housing opening 61. For that reason, when the second terminal
portion 172b and the second bridge portion 173b are joined together
by using the joining tool, the joining operation can be
facilitated.
[0386] According to the present embodiment, the connector terminal
28a is temporarily attached to the temporary support portion 178 of
the mold device 90, so that the housing 21 which is in a state in
which the connector terminal 28a is embedded is molded with resin.
For that reason, the connector terminal 28a can be inhibited from
being positionally deviated with respect to the housing 21.
[0387] According to the present embodiment, the sensor SA 50, the
connector terminal 28a and the bridge terminal 86 are hidden by the
thermosetting resin injected into the internal space 24a from the
housing opening 61. For that reason, the positional deviation of
the sensor SA 50 and the deformation or breakage of the lead
terminal 54, the connector terminal 28a, and the bridge terminal 86
can be inhibited by the potting portion 65 made of the
thermosetting resin.
[0388] <Configuration Group F>
[0389] A configuration group F relating to covering the detection
unit will be described with reference to FIGS. 40 to 42 and the
like.
[0390] As shown in FIGS. 40 and 41, the inner peripheral surface of
the lip 89 and the inner peripheral surface of the housing body 24
are flush with each other, and the inner peripheral surface 180 of
the sealing region PA extends straight in the height direction Y
from the region step surface 66 and the sealing step surface 67
toward the housing opening 61. The lip 89 extends along the
peripheral portion of the internal space 24a to form the housing
opening 61, and corresponds to an open rib portion.
[0391] As described above, the sealing region PA including the
housing opening 61 is formed in a rectangular shape as a whole in
top view, but four corners are curved. In that case, the inner
peripheral surface 180 of the sealing region PA has a flat inner
peripheral flat surface 181 extending in the width direction X and
the depth direction Z in the housing opening 61, and an inner
peripheral curved surface 182 curved so as to connect the inner
peripheral flat surfaces 181 crossing each other. The inner
peripheral curved surface 182 is curved so as to bulge toward the
outer peripheral side so that an acute angle or a right-angled
corner portion is not formed in the housing opening 61. The inner
peripheral curved surface 182 corresponds to an inner peripheral
curved surface that is bent so as to bulge toward the outer
peripheral side of the sealing region PA.
[0392] In the inner peripheral surface 180 of the sealing region
PA, the inner peripheral flat surface 181 is disposed at a position
corresponding to the four sides of the housing opening 61, and the
inner peripheral curved surface 182 is disposed at a position
corresponding to the four corners. Since the inner peripheral flat
surface 181 and the inner peripheral curved surface 182 are
continuous with each other, no step is formed at the boundary
between the inner peripheral flat surface 181 and the inner
peripheral curved surface 182. The inner peripheral flat surface
181 and the inner peripheral curved surface 182 extend from the
housing opening 61 toward the region step surface 66 and the
sealing step surface 67.
[0393] As described above, in the housing 21, the flange portion 27
extends from the housing body 24 in the width direction X and the
depth direction Z, and the ring holding portion 25 is disposed
closer to the housing tip side than the flange portion 27. On the
other hand, the lip 89 extends from the housing body 24 toward the
housing base end side. In this case, if the housing attachment is
configured to include the ring holding portion 25 and the flange
portion 27, the lip 89 is disposed on the opposite side of the
bypass flow channel 30 and the inflow port 33a across the housing
attachment. In other words, in the height direction Y, the housing
opening 61 is disposed on the opposite side of the inflow port 33a
across the sensor SA 50.
[0394] As described above, the lead terminal 54 of the sensor SA 50
and the connector terminal 28a are connected to each other, and the
connection portion 183 is accommodated in the sealing region PA.
The connection portion 183 includes each portion of the lead
terminal 54 connected to the bridge terminals 86, a portion of the
connector terminal 28a connected to the bridge terminal 86, and the
entire bridge terminal 86. The connection portion 183 may include
the whole of the second terminal portion 172b of the connector
terminal 28a (refer to FIG. 34) and the whole of the lead terminal
54.
[0395] Next, a manufacturing method of the air flow meter 14 will
be described focusing on a procedure for creating the potting
portion 65. The potting portion 65 corresponds to a filling
portion.
[0396] First, the sensor SA 50 is installed in the internal space
24a of the housing 21, and the lead terminals 54 and the connector
terminal 28a are connected to each other with the use of the
terminal unit 85. Then, as shown in FIG. 42, a step of injecting
the potting material 185, which is a thermosetting resin, into the
internal space 24a through the housing opening 61 is performed so
that the potting material 185 does not overflow from the internal
space 24a. In this injection step, the internal space 24a is sealed
by filling the internal space 24a with a liquid or fluid potting
material 185. In this example, the potting material 185 may also be
referred to as a sealing material. In the present embodiment, for
example, epoxy resin is used as the potting material 185, and the
potting material 185 corresponds to a filler.
[0397] The potting material 185 corresponds to a potting resin and
a curable resin. As the potting material 185, a urethane resin or a
silicone resin may be used. When the urethane resin or the silicone
resin is used as the potting material 185, the potting portion 65
tends to be softer than when the epoxy resin is used as the potting
material 185.
[0398] In this injection step, an injection operation is performed
so that a mass of air such as a void or a gap is not formed in the
potting material 185 filled in the sealing region PA. In this
example, in the sealing region PA, an acute angle or a right-angled
inward portion does not exist due to the inner circumference curved
surface 182. In this case, a gap is less likely to occur between
the potting material 185 and the inner peripheral surface 180 of
the sealing region PA, and a phenomenon that the potting material
185 creeps up toward the housing opening 61 along the inner
peripheral surface 180 of the sealing region PA is less likely to
occur.
[0399] In the injecting step, the potting material 185 is filled in
the sealing region PA so that the sensor SA 50, the connection
portion 183, and the connector terminal 28a are hidden from the
housing opening 61. In this example, in the inner peripheral
surface 180 of the sealing region PA, it is considered that the
creep-up phenomenon occurs somewhat even if the creep-up phenomenon
of the potting material 185 is less likely to occur due to the
inner curved surface 182. Therefore, the injection amount of the
potting material 185 is set so that the center portion of the
surface of the potting material 185 is positioned slightly inward
from the housing opening 61 so that the potting material 185 does
not overflow from the housing opening 61 even if the creep-up
phenomenon occurs.
[0400] In the internal space 24a, the connection portion between
the lead terminal 54 and the intake air temperature terminal 23c is
also covered with the potting material 185. The connection portion
between the lead terminal 54 and the intake air temperature
terminal 23c includes a connection portion between the lead
terminal 54 and the bridge terminal 86 in the intake air
temperature terminal 23c, and the entire bridge terminal 86.
[0401] After the potting material 185 has been injected, the
potting material 185 is heated and cured to form the potting
portion 65. In this example, the hardness and the like of the
potting portion 65 differ depending on the component and the like
of the type of the potting material 185. Regardless of the hardness
of the potting portion 65, the potting portion 65 can inhibit the
occurrence of positional deviation of the sensor SA 50 in the
internal space 24a, but as the potting portion 65 is harder, the
inhibiting effect against the positional deviation of the sensor SA
50 is higher. In addition, the potting portion 65 is softer, the
potting portion 65 more easily adheres to the sealing region PA,
the sensor SA 50, and the connection portion 183, so that the
sealing property of the potting portion 65 can be enhanced.
[0402] The potting portion 65 covers the sensor SA 50 from the
housing opening 61, and corresponds to the cover portion. In that
case, the potting portion 65 covers the connection portion between
the lead terminal 54 and the connector terminal 28a from the
housing opening 61 side. The potting material 185 corresponds to a
covering material.
[0403] In the configuration group F, according to the present
embodiment, since the potting portion 65 is formed by injecting the
potting material 185 into the internal space 24a, a pressure is
less likely to be applied to the internal space 24a when the
internal space 24a is sealed. In this case, since the positional
deviation of the sensor SA 50 is inhibited from being
unintentionally generated by the pressure applied to the internal
space 24a, the positional deviation of the sensor SA 50 is less
likely to be generated from product to product. Therefore, the
detection accuracy of the flow rate detector 22 can be inhibited
from varying from product to product.
[0404] According to the present embodiment, the housing opening 61
is defined by the lip 89 protruding from the housing body 24. For
that reason, the depth dimensions of the internal space 24a and the
sealing region PA in the height direction Y can be changed by
simply changing the protrusion dimension of the lip 89 without
changing the shape or size of the housing body 24. In this
instance, the depth dimensions of the internal space 24a and the
sealing region PA can be appropriately set in accordance with the
length dimension of the sensor SA 50 in the height direction Y
without decreasing the versatility of the housing body 24. This
makes it possible to avoid that the sensor SA 50 is too long
relative to the internal space 24a and a part of the sensor SA 50
protrudes from the potting material 185 even though the internal
space 24a is sealed by the potting material 185.
[0405] According to the present embodiment, the inner peripheral
curved surface 182 is included in the inner peripheral surface 180
of the sealing region PA. This makes it possible to inhibit a gap
from being generated between the potting material 185 and the inner
peripheral surface 180, or the potting material 185 from creeping
up along the inner peripheral surface 180 and overflowing from the
housing opening 61. Therefore, the sealing performance of the
internal space 24a by the potting material 185 can be appropriately
exhibited.
[0406] According to the present embodiment, in the air flow meter
14, the housing opening 61 is disposed on the opposite side to the
inflow port 33a across the ring holding portion 25. For that
reason, a configuration can be realized in which the housing
opening 61 is disposed outside the intake pipe 12a instead of the
intake passage 12. In this case, since the potting portion 65 is
not always exposed to the intake air flowing through the intake
passage 12, damage or deterioration of the potting portion 65 can
be inhibited. As a result, the sealing performance of the internal
space 24a by the potting portion 65 can be exhibited for a long
period of time.
[0407] According to the present embodiment, in the internal space
24a, the connection portion 183 between the lead terminal 54 and
the connector terminal 28a is covered with the potting portion 65
in addition to the sensor SA 50. For that reason, not only the
sensor SA 50 but also the connection portion 183 can be protected
by the sealing performance of the potting portion 65.
[0408] <Configuration Group G>
[0409] A configuration group G relating to an information portion
will be described with reference to FIG. 43 and the like.
[0410] As shown in FIG. 43, in the housing 21, when one end face is
referred to as a housing tip end face 191 and the other end face is
referred to as a housing base end face 192, the housing opening 61
is provided in the housing base end face 192. The housing base end
face 192 is formed by the outer peripheral surfaces of the housing
body 24, the flange portion 27, and the connector portion 28, and
the housing opening 61 is disposed in the outer peripheral surface
of the housing body 24. The housing base end face 192 is provided
with the multiple thinned portions 41 and the screw holes 42 in
addition to the housing opening 61, and the thinned portions 41 and
the screw holes 42 are disposed in the outer peripheral surface of
the flange portion 27. The housing base end face 192 corresponds to
a housing face which is one surface of the housing. Further, the
housing tip end face 191 and the housing base end face 192 are
aligned in the height direction Y.
[0411] The housing opening 61 is an open end portion of the
internal space 24a, and as described above, the internal space 24a
is sealed from the housing opening 61 side by the potting portion
65. In the potting portion 65, a potting surface 193, which is an
outer surface thereof, faces a side opposite to the sensor SA 50 in
the height direction Y like the housing base end face 192. Further,
as described above, the potting material 185 filled in the internal
space 24a creeps up the inner peripheral surface 180 of the sealing
region PA, so that the peripheral portion of the potting surface
193 is easily curved. However, most of the potting surface 193 is
flat surface except for the peripheral portion. In this case, the
potting portion 65 corresponds to a sealing portion, and the
potting surface 193 corresponds to an outer surface of the sealing
portion.
[0412] In the housing 21, the housing opening 61 is disposed on the
side opposed to the inflow port 33a across the sensor SA 50 in the
height direction Y. In this case, the inflow port 33a is disposed
inside the intake pipe 12a in the intake passage 12, while the
potting portion 65 is disposed outside the intake pipe 12a. In the
potting portion 65, the potting surface 193 faces a side opposite
to the intake pipe 12a in the height direction Y.
[0413] As described above, the housing opening 61 is formed in a
rectangular shape as a whole. In this case, the housing opening 61
has a pair of first side portions 195, which are long sides, and a
pair of second side portions 196, which are short sides, and has a
flat shape extending in the depth direction Z as a whole. In this
case, the first side portions 195 extend in the depth direction Z,
and the second side portions 196 extend in the width direction X.
The housing opening 61 is chamfered at four corners, and the
chamfered portions are curved toward the outer peripheral side in a
state in which the first side portions 195 and the second side
portions 196 are connected to each other. The first side portions
195 correspond to opposite sides. Also, the chamfered portions may
extend straight, rather than curved, or may be bent. The chamfered
portions may not be disposed at all four corners of the housing
opening 61.
[0414] The potting surface 193 is provided with an information
portion 194 indicating predetermined information determined in
advance. The information portion 194 has numbers, characters,
marks, and the like, the marks include symbols, logos, storing
marks, and the like, and the storage marks include two-dimensional
codes and the like. Various types of information are stored in the
storage marks, and the various types of information include
correction values used for correction of detection signals of the
flow rate detector 22, the intake air temperature sensor 23, and
the like when the detection signals are corrected by the circuit
chip 81 or the ECU 20. In addition to the correction values, the
various types of information include a characteristic map
indicating the characteristics of the flow rate detector 22, the
intake air temperature sensor 23, the air cleaner 19, and the
like.
[0415] The information portion 194 is formed of ink, paint, and
unevenness applied to the potting surface 193. As a method of
applying the information portion 194 to the potting surface 193,
laser marking, ink marking, or the like can be given. The
information portion 194 has a number string or a character string
formed by multiple numbers or characters to indicate various
information, and the number strings or the character strings are
aligned along the first side portions 195. In this case, since the
user or the like only needs to read the information displayed by
the information portion 194 along the first side portion 195, the
content of the information portion 194 is hardly erroneously read.
The information portion 194 is arranged in a wide range of the
potting surface 193, but is basically arranged in a flat portion of
the potting surface 193.
[0416] In the configuration group G, according to the present
embodiment, since the potting portion 65 is formed by injecting the
potting material 185 into the internal space 24a, most of the
potting surface 193 can be flattened. In addition, since the
housing opening 61 and the internal space 24a are large enough to
allow the sensor SA 50 to be inserted into the housing opening 61
and the internal space 24a, the potting surface 193 is less likely
to be insufficient for displaying the information portion 194. In
this manner, since the potting surface 193 is flattened and
enlarged, the visibility of the information portion 194 imparted to
the potting surface 193 can be enhanced.
[0417] According to the present embodiment, in the internal space
24a of the housing 21, the SA main body 170 of the sensor SA 50 and
the connector terminals 28a are aligned laterally in the width
direction X. For that reason, the width dimension of the internal
space 24a and the width dimension of the housing opening 61 are
increased in the width direction X to such an extent that the SA
main body 170 and the connector terminals 28a can be aligned
laterally. In other words, the width dimension of the potting
surface 193 increases in the width direction X. In that case, since
the size of the information portion 194 can be enlarged on the
potting surface 193, the visibility of the information portion 194
can be enhanced.
[0418] According to the present embodiment, since the housing
opening 61 is disposed on the side opposed to the inflow port 33a
across the sensor SA 50 in the height direction Y, the potting
surface 193 is disposed outside the intake pipe 12a. In that case,
the operator can visually recognize the potting surface 193 and the
information portion 194 while the air flow meter 14 is attached to
the intake pipe 12a. Therefore, when visually recognizing the
information portion 194, a labor of detaching the air flow meter 14
from the intake pipe 12a can be saved.
[0419] According to the present embodiment, since the housing
opening 61 is flattened as a whole so that the pair of first side
portions 195 are long sides, the alignment direction of the
information portions 194 can be clarified. In this case, since the
number string and the character string of the information portion
194 are aligned along the first side portions 195 on the potting
surface 193, the operator can be inhibited from reading the number
string and the character string incorrectly. In this manner, the
visibility of the information portion 194 can be enhanced by the
shape of the potting surface 193.
[0420] According to the present embodiment, the housing base end
face 192 is provided with the thinned portions 41. In this example,
if an attempt is made to secure a flat surface on the housing base
end face 192 which is large enough not to cause insufficient
visibility of the information portion 194, there is a fear that the
thinned portions 41 on the housing base end face 192 will be
insufficient. If there is a shortage of the thinned portions 41 at
the housing base end face 192, there is a fear that the housing 21
is thickened, and the unintentional deformation of the housing 21
may occur due to curing of the molten resin when the housing 21 is
molded with resin. On the other hand, in the present embodiment,
since the information portion 194 is provided to the potting
surface 193, there is no need to secure a flat surface suitable for
display of the information portion 194 on the housing base end face
192. In this case, the sufficient thinned portions 41 is disposed
on the housing base end face 192, so that deformation of the
housing 21 due to resin molding can be inhibited, and visibility of
the information portion 194 on the potting surface 193 can be
enhanced.
[0421] According to the present embodiment, the sensor SA 50 is
covered with the potting portion 65 in the internal space 24a of
the housing 21. In this example, unlike the present embodiment, for
example, in a configuration in which a lid member resin molded as a
separate member from the housing 21 is attached to the housing
opening 61, as the housing opening 61 is larger in size, the lid
member becomes larger in size. When the lid member is increased in
size, it is considered that the lid member needs to be formed to be
thick enough so that the lid member can retain its own shape, and
on the other hand, it is also considered that there is a need to
form a thinned portion in the lid member so as not to cause
deformation due to resin molding. This makes it difficult for the
lid member to secure a flat surface to the extent that the
information portion 194 can be provided.
[0422] On the other hand, according to the present embodiment,
there is no need to form the thinned portions 41 in the potting
portion 65 to which the information portion 194 is given because
the resin molding is not performed. In addition, with the
utilization of the phenomenon that the potting surface 193 is
inevitably flattened with respect to the potting portion 65 filled
in the internal space 24a, the information portion 194 can be
disposed almost entirely on the potting surface 193. Therefore, the
visibility of the information portion 194 can be enhanced on the
potting surface 193.
[0423] <Configuration Group H>
[0424] A configuration group H related to correcting the detection
result of the physical quantity detector will be described with
reference to FIGS. 44 to 57 and the like.
[0425] As shown in FIG. 44, the air flow meter 14 has an inward
part 501 which enters the inside of the intake pipe 12a, and an
outward part 502 which protrudes to the outside of the intake pipe
12a without entering the inside of the intake pipe 12a. The inward
part 501 includes the bypass flow channel 30 and the ring holding
portion 25, and the outward part 502 includes the housing opening
61, the flange portion 27, and the connector portion 28. The inward
part 501 and the outward part 502 are aligned in the height
direction Y to divide the air flow meter 14 into two portions, and
a boundary of those parts 501 and 502 coincide with the open end of
the pipe flange 12c. The housing body 24 and the sensor SA 50
extend across a boundary between the inward part 501 and the
outward part 502 in the height direction Y.
[0426] In the air flow meter 14, the outward part 502 includes the
housing base end face 192, and the inward part 501 includes the
housing tip end face 191. In this case, in the housing 21, the
housing base end face 192 may be referred to as the end on the side
of the outward part 502, and the housing tip end face 191 may be
referred to as the end on the side of the inward part 501. In
addition, the inward part 501 and the outward part 502 are aligned
in the height direction Y, and the height direction Y corresponds
to a direction in which the inward part 501 and the outward part
502 are aligned.
[0427] The air flow meter 14 has temperature detectors 505 and 506
for detecting the temperature of intake air flowing through the
intake passage 12, in addition to the flow rate detector 22. The
temperature detectors 505 and 506 are sensors configured to include
elements such as temperature detection elements mounted on a
circuit board, and detect an internal temperature of the intake
pipe 12a.
[0428] The first temperature detector 505 is provided in the
measurement flow channel 32, and detects a temperature of the
intake air in the measurement flow channel 32. The first
temperature detector 505 detects the temperature of the intake air
flowing in the intake passage 12 by detecting the temperature of
the intake air flowing in the measurement flow channel 32. The
first temperature detector 505 is disposed in the sensing portion
53 of the sensor SA 50, and specifically, the first temperature
detector 505 is mounted on the detection board 22a together with
the detection element 22b. In this case, the detection board 22a
corresponds to a circuit board on which the elements of the first
temperature detector 505 are mounted.
[0429] The second temperature detector 506 is disposed at a
position closer to the housing opening 61 than the first
temperature detector 505 in the height direction Y, and detects the
internal temperature of the air flow meter 14. The second
temperature detector 506 detects the internal temperature of the
intake pipe 12a by detecting the internal temperature of the air
flow meter 14 even if the second temperature detector 506 is
disposed at a position where the second temperature detector 506
does not touch the intake air. The second temperature detector 506
is disposed between the housing base end face 192 and the first
temperature detector 505 in the height direction Y by being
disposed at a position closer to the housing opening 61 than the
measurement flow channel 32. The second temperature detector 506 is
disposed in the circuit accommodation portion 51 of the sensor SA
50, and specifically, the second temperature detector 506 is
mounted on the lead frame 82 together with the circuit chip 81. In
this case, the lead frame 82 corresponds to a circuit board on
which the elements of the second temperature detector 506 are
mounted.
[0430] In the internal space 24a of the housing 21, the first
temperature detector 505 is disposed in the sealing region PA
(refer to FIG. 8, and so on), and the second temperature detector
506 is disposed in the open region PB (refer to FIG. 8, and so
on).
[0431] In this example, the internal combustion engine 11 or the
like that generates a heat outside the intake pipe 12a is referred
to as an external heat source, and it is assumed that the heat is
applied from the external heat source to the air flow meter 14. In
the air flow meter 14, it is considered that the heat from the
external heat source is first applied to the outward part 502, and
the heat is transferred from the outward part 502 to the inward
part 501. In this case, since the heat from the external heat
source is applied to the temperature detectors 505 and 506 in
addition to the heat from the intake air, an error is likely to
occur between the detected value, which is the detection result of
the temperature detectors 505 and 506, and an actual temperature of
the intake air flowing through the intake passage 12. Hereinafter,
the actual temperature of the intake air flowing through the intake
passage 12 is also referred to as an actual temperature of the
intake air. The actual temperature may also be referred to as a
steady value.
[0432] As described above, the first temperature detector 505 is
disposed at a position farther from the outward part 502 than the
second temperature detector 506. In addition, while the second
temperature detector 506 is disposed at a position of hardly
touching the intake air, the first temperature detector 505 is
disposed at a position of easily touching the intake air in the
measurement flow channel 32. Due to the above factors, the detected
value of the first temperature detector 505 is less susceptible to
the influence of the external heat source than the detected value
of the second temperature detector 506, and tends to be a value
close to the actual temperature of the intake air. In other words,
the error of the first temperature detector 505 with respect to the
actual temperature of the intake air is likely to be smaller than
the error of the second temperature detector 506 with respect to
the actual temperature of the intake air.
[0433] The circuit chip 81 according to the present embodiment
performs a process of acquiring a temperature correction value
obtained by correcting the detected value of the first temperature
detector 505 as a temperature measurement value. The circuit chip
81 corresponds to a measurement control device that controls the
air flow meter 14, such as acquiring a temperature correction value
as a measured value. Like the ECU 20, the circuit chip 81 is an
arithmetic processing circuit including a processor, a RAM, a
storage medium such as a ROM and a flash memory, a microcomputer
including an input and output unit, a power supply circuit, and the
like. The circuit chip 81 is electrically connected to the flow
rate detector 22, the intake air temperature sensor 23, and the
temperature detectors 505 and 506, and the detection signals of the
detectors 22, 505, and 506 and the sensor 23 are input to the
circuit chip 81. The circuit chip 81 measures the flow rate and the
temperature of the intake air flowing through the measurement flow
channel 32 with the use of the detection signals of the detectors
22, 505, 506 and the sensor 23.
[0434] As shown in FIG. 45, the multiple connector terminals 28a of
the air flow meter 14 include a signal terminal 521, a power supply
terminal 522, a ground terminal 523, and an adjustment terminal
524. Each of the terminals 521 to 524 is electrically connected to
the circuit chip 81, and the circuit chip 81 outputs measured
values of temperatures and flow rates from the signal terminal 521
to the ECU 20 or the like. In this example, the circuit chip 81
stores the information on the temperature correction value in the
storage medium in association with time information such as
correction timing. The adjustment terminal 524 can be connected
with an adjustment device as an external device capable of
adjusting the correction accuracy by the circuit chip 81. In a
state where the adjustment device is electrically connected to the
adjustment terminal 524, the information on the temperature
correction value stored in the storage medium can be rewritten.
[0435] The circuit chip 81 includes a temperature correction unit
510 that acquires a temperature correction value by correcting the
detected value of the first temperature detector 505. As shown in
FIG. 46, the temperature correction unit 510 includes multiple
functional blocks such as a first correction unit 511, a
temperature differential unit 512, a second correction unit 513, a
characteristic transformation unit 514, a correction amount
calculation unit 515, and a correction value calculation unit 516.
In the temperature correction unit 510 corresponding to the
physical quantity correction unit, the detection results of the
flow rate detector 22 and the temperature detectors 505 and 506 are
input to the first correction unit 511, the temperature
differential unit 512, and the characteristic transformation unit
514. In the temperature correction unit 510, the detected value of
the flow rate and the detected value of the temperature are
acquired based on the detection signals of the flow rate detector
22 and the temperature detectors 505 and 506.
[0436] In the present embodiment, the first temperature signal Sa1
is corrected with the use of a first temperature signal Sa1
including the detected value of the first temperature detector 505,
a second temperature signal Sa2 including the detected value of the
second temperature detector 506, and a flow rate signal Sa3
including the detected value of the flow rate detector 22. In the
temperature correction unit 510, the first temperature signal Sa1
is input to the first correction unit 511 and the temperature
differential unit 512, the second temperature signal Sa2 is input
to the temperature differential unit 512, and the flow rate signal
Sa3 is input to the characteristic transformation unit 514.
[0437] The first temperature detector 505 corresponds to a physical
quantity detector that detects a physical quantity called a
temperature, and the first temperature signals Sa1 correspond to
detection results of the physical quantity detector. The second
temperature detector 506 corresponds to a same kind-quantity
detector that detects a temperature having the same kind of
physical quantity as the first temperature detector 505, and the
second temperature signal Sa2 corresponds to detection results of
the same kind-quantity detector. The flow rate detector 22
corresponds to a different kind-quantity detector that detects a
flow rate which is a physical quantity of a different type from
that of the first temperature detector 505, and the flow rate
signals Sa3 correspond to detection results of the different
kind-quantity detector. The second temperature signal Sa2 and the
flow rate signal Sa3 correspond to correction parameters used for
correction of the first temperature signal Sa1.
[0438] The first correction unit 511 calculates a first correction
signal Sb1 by performing response correction of the first
temperature signal Sa1. The temperature differential unit 512
calculates a difference, which is a difference between the first
temperature signal Sa1 and the second temperature signal Sa2, as a
temperature differential signal Sb2. The second correction unit 513
calculates a differential correction signal Sb3 by performing
response correction of the temperature differential signal Sb2. The
characteristic transformation unit 514 calculates a flow rate
transformation signal sb4 by performing characteristic
transformation of the flow rate signal Sa3. The correction amount
calculation unit 515 calculates a correction amount signal Sb5 with
the use of the differential correction signal Sb3 and the flow rate
transformation signal sb4. The correction value calculation unit
516 calculates a correction value signal Sc with the use of the
first correction signal Sb1 and the correction amount signal
Sb5.
[0439] The first correction unit 511 corrects the first temperature
signal Sa1 based on a behavior of change of the first temperature
signal Sa1, and acquires the correction value as the first
correction signal Sb1. In this case, the first correction unit 511
corresponds to a change correction unit. In this example, a
first-order delay correction is performed on the first temperature
signal Sa1 as shown in FIG. 47 to obtain the first correction
signal Sb1. For example, in the first temperature signal Sa1, a
detected value Sa1 (tn) at a timing tn, a past slope m, and a time
constant A are acquired, and the detected value Sa1 (tn) is added
to the multiplication of the slope m and the time constant A,
thereby calculating the correction value Sb1 (tn) at the timing tn.
In this manner, the first correction signal Sb1 is acquired by
calculating the respective correction values Sb1 (tn) with the use
of the following (Expression 1).
Sb1(tn)=Sa1(tn)+m.times.A (Ex. 1)
[0440] In (Ex. 1), the slope m is calculated by dividing an amount
of change .DELTA.Sa1 of the first temperature signal Sa1 in a
minute time .DELTA.t by the minute time .DELTA.t. For example, the
minute time .DELTA.t is calculated for timings tn and tn-1, and an
amount of change .DELTA.Sa1 is calculated with the use of the
detected values Sa1 (tn) and Sa1 (tn-1) at the timings tn and
tn-1.
[0441] The time constant A is set in accordance with a flow rate of
intake air in the intake passage 12. For example, as shown in FIG.
48, the time constant A is set to a larger value as the flow rate
signal Sa3 is smaller. Information indicating a relation between
the flow rate signal Sa3 and the time constant A is stored as flow
time information such as a map, data, and a mathematical expression
in the storage medium of the circuit chip 81. The first correction
unit 511 reads the flow time information from the storage medium or
the like, and calculates the time constant A corresponding to the
flow rate signal Sa3 with the use of the flow time information or
the like. In this instance, the first correction unit 511 corrects
the first temperature signal Sa1 with the use of a flow rate which
is a physical quantity of a kind different from the temperature,
and corresponds to a different king-quantity correction unit.
[0442] The first temperature signal Sa1 converges to a convergence
value corresponding to the actual temperature of the intake air and
stabilizes at a convergence value even if the first temperature
signal Sa1 is not corrected based on the behavior of change of the
first temperature signal Sa1. As the flow rate of the intake air in
the intake passage 12 increases more, the heat imparted to the air
flow meter 14 from the external heat source is more likely to be
released in the intake passage 12, the first temperature signal Sa1
is more likely to converge to the convergence value, and the
response of the first temperature signal Sa1 becomes higher. For
that reason, as shown in FIG. 49, when the flow rate of the intake
air in the intake passage 12 is relatively large, the first
correction signal Sb1 tends to converge to the convergence value
even if the correction amount is relatively small. On the other
hand, if the flow rate of the intake air in the intake passage 12
is relatively small, there is a need to relatively increase the
correction amount in order to converge the first correction signal
Sb1 to the convergence value. Therefore, as described above, it is
preferable to set the time constant A to a larger value as the flow
rate of the flow rate signal Sa3 and the like is smaller. The time
constant A corresponds to a flow rate correction amount.
[0443] The response of the first correction signal Sb1 is enhanced
by compensating the response of the first temperature signal Sa1
with the use of the behavior of change as the temporal change
information included in the first temperature signal Sa1. As shown
in FIG. 50, a time Tb required for the first correction signal Sb1
to reach a first convergence value Ev1, which is the convergence
value for the first temperature signal Sa1, is shorter than the
time Tb required for the first temperature signal Sa1 to reach the
first convergence value Ev1. For example, when the first
temperature signal Sa1 and the first correction signal Sb1 start to
change at the timing t0 in accordance with a change in the actual
temperature of the intake air, the first temperature signal Sa1
reaches the first convergence value Ev1 at a timing t2. On the
other hand, the first correction signal Sb1 reaches the first
convergence value Ev1 at a timing t1 earlier than the timing t2. As
described above, the first correction signal Sb1 is higher in
response than the first temperature signal Sa1. In other words,
when the actual temperature of the intake air starts to change, the
first correction signal Sb1 is smaller than the first temperature
signal Sa1 in the error from the first convergence value Ev1, which
means that the accuracy of the first correction signal Sb1 is
higher. This is because the first correction unit 511 sets the time
constant A to be larger as the flow rate signal Sa3 is smaller in a
transient time of the actual temperature.
[0444] In this example, when the heat is applied to the air flow
meter 14 from the external heat source, an error between the actual
temperature and the first temperature signal Sa1 becomes larger,
and in addition, the response of the first temperature signal Sa1
when the actual temperature of the intake air changes tends to
decrease. This is because it is considered that the heat from the
external heat source is transmitted from the housing 21 to the
first temperature detector 505 through the mold portion 76 of the
sensor SA 50 and the intake air in the measurement flow channel 32.
On the other hand, even if the response of the first temperature
signal Sa1 is lowered by the heat from the external heat source,
the response of the first correction signal Sb1 is enhanced by the
first correction unit 511.
[0445] When the response of the first correction signal Sb1 is
increased more, the response of the correction value signal Sc is
increased more. In this example, the correction value signal Sc is
output from the circuit chip 81 to the ECU 20 as information on the
temperature of the intake air, and the correction value signal Sc
is used by the ECU 20 to control the combustion system 10. For that
reason, if the response of the correction value signal Sc is
enhanced, an improvement in fuel efficiency and emission can be
realized, and erroneous diagnosis of a failure diagnosis device
such as an OBD (On-board diagnostics) can be inhibited.
[0446] The temperature differential unit 512 calculates the
temperature differential signal Sb2 based on one of the first
temperature signal Sa1 and the second temperature signal Sa2. The
temperature differential unit 512 of the present embodiment uses
the first temperature signal Sa1 as a reference, and as shown in
FIG. 51, uses a value obtained by subtracting the first temperature
signal Sa1 from the second temperature signal Sa2 as the
temperature differential signal Sb2. In FIG. 51, the second
convergence value Ev2, which is the convergence value for the
second temperature signal Sa2, is larger than the first convergence
value Ev1. As described above, a case in which the second
convergence value Ev2 is larger than the first convergence value
Ev1 includes a case in which the heat applied to the first
temperature detector 505 from the external heat source is larger
than the heat applied to the first temperature detector 505 from
the intake air flowing through the measurement flow channel 32.
[0447] When the response of the second temperature signal Sa2 is
higher than the response of the first temperature signal Sa1, as
shown in FIG. 52, the temperature differential signal Sb2 gradually
increases, and eventually reaches a neighborhood difference
.DELTA.Ev, which is a difference between the first convergence
value Ev1 and the second convergence value Ev2. In this example,
because an error between the first temperature signal Sa1 and the
first convergence value Ev1 is larger than an error between the
second temperature signal Sa2 and the second convergence value Ev2,
the temperature differential signal Sb2 gradually increases toward
the neighborhood difference .DELTA.Ev with the first temperature
signal Sa1 as a reference.
[0448] The second correction unit 513 corrects the temperature
differential signal Sb2 based on a behavior of change of the
temperature differential signal Sb2, and acquires a correction
value as the differential correction signal Sb3. The second
correction unit 513 performs the first-order delay correction with
the use of the present value and the past value, similarly to the
first correction unit 511, for example, for the temperature
differential signals Sb2. As a result, the response of the
differential correction signal Sb3 is higher than the response of
the temperature differential signal Sb2. Specifically, as shown in
FIG. 52, a time required for the differential correction signal Sb3
to reach the neighborhood difference .DELTA.Ev is shorter than a
time required for the temperature differential signal Sb2 to reach
the neighborhood difference .DELTA.Ev. This is because, as shown in
FIG. 53, the second correction unit 513 sets the differential
correction amount of the correction amount signal Sb5 or the like
to a larger value as the temperature differential signal Sb2
becomes larger at the transient time of the actual temperature.
[0449] Information indicating the relation between the temperature
differential signal Sb2 and the differential correction signal Sb3
is stored as temperature compensation information such as a map,
data, and a mathematical expression in the storage medium of the
circuit chip 81. The second correction unit 513 reads the
temperature compensation information from the storage medium or the
like, and calculates the differential correction signal Sb3
corresponding to the temperature differential signal Sb2 with the
use of the temperature compensation information or the like. In
this instance, the second correction unit 513 corresponds to a
differential correction unit, and the differential correction
signal Sb3 corresponds to a differential correction amount.
[0450] As described above, after calculating the difference between
the first temperature signal Sa1 and the second temperature signal
Sa2, the temperature correction unit 510 calculates the
differential correction signal Sb3 by performing the response
correction of the difference. On the other hand, unlike the present
embodiment, a configuration is conceivable in which the difference
between the first correction signal Sb1 and the second temperature
signal rather than the first temperature signal Sa1 is calculated
as a differential correction signal Sx. In the above configuration,
as shown in FIGS. 54 and 55, the differential correction signal Sx
reaches the neighborhood difference .DELTA.Ev with a gradual
decrease after the differential correction signal Sx once becomes
larger than the neighborhood difference .DELTA.Ev. In other words,
in the differential correction signal Sx, an overshoot occurs at an
initial stage of the response. As described above, when the
differential correction signal Sx includes an overshoot, the
correction value signal also includes an overshoot. When it is
assumed that the correction value signal is used for controlling
the combustion system 10 in the ECU 20, there are concerns that the
fuel efficiency and the emission are lowered, and that the
diagnostic accuracy of the failure diagnosis device is lowered.
[0451] The time information of the differential correction signal
Sb3 acquired by the second correction unit 513 matches the time
information of the first correction signal Sb1 acquired by the
first correction unit 511. For example, in the first correction
unit 511, the temperature differential unit 512, and the second
correction unit 513, various processes are performed on the first
temperature signal Sa1, the second temperature signal Sa2, and the
temperature differential signal Sb2, as a result of which some
response delay occurs. On the other hand, the response delay time
generated in the first correction unit 511 is the same as the total
time of the response delay times generated in the temperature
differential unit 512 and the second correction unit 513. In this
instance, the first correction signal Sb1 and the differential
correction signal Sb3 included in the correction value signal Sc
have the same time information, and the measurement accuracy of the
correction value signal Sc is improved as compared with, for
example, a configuration in which the first correction signal Sb1
and the differential correction signal Sb3 have different time
information.
[0452] The time information of the first correction signal Sb1 and
the time information of the differential correction signal Sb3 may
not coincide with each other. Even in this case, if the deviation
of the time information is a slight deviation amount such as being
included in an appropriate range, the measurement accuracy of the
correction value signal Sc is kept in an appropriate range, and the
measurement accuracy is inhibited from being remarkably
lowered.
[0453] The characteristic transformation unit 514 performs
characteristic transformation of the flow rate signal Sa3 so that
the content of the flow rate signal Sa3 is reflected in the
response correction in the first correction unit 511 and so that
the content of the flow rate signal Sa3 is reflected in the
response correction in the second correction unit 513, and
calculates the flow rate transformation signal sb4. The
characteristic transformation unit 514 is connected to each of the
first correction unit 511 and the second correction unit 513, and
outputs the flow rate transformation signal Sb4 to the correction
units 511 and 513. For example, the flow rate transformation signal
sb4 converts the flow rate signal Sa3 into a mode that is easily
applied to the first temperature signal Sa1 or the flow time
information as shown in FIG. 48.
[0454] The correction amount calculation unit 515 acquires, as the
correction amount signal Sb5, a multiplied signal obtained by
multiplying the differential correction signal Sb3 by the flow rate
transformation signal sb4. In this instance, the correction amount
calculation unit 515 calculates, as the correction amount signal
Sb5, a value obtained by increasing or decreasing the differential
correction signal Sb3 in accordance with the flow rate of the
intake air in the measurement flow channel 32.
[0455] The correction value calculation unit 516 acquires an
integrated signal obtained by adding the first correction signal
Sb1 and the correction amount signal Sb5 as the correction value
signal Sc. In this instance, the correction value calculation unit
516 calculates, as the correction value signal Sc, a value obtained
by increasing or decreasing the first correction signal Sb1 in
accordance with both the temperature difference between the first
temperature detector 505 and the second temperature detector 506
and the flow rate of the intake air in the measurement flow channel
32. The correction value signal Sc may also be referred to as a
temperature correction value or a temperature measurement
value.
[0456] As shown in FIGS. 56 and 57, a correction convergence value
Ev3, which is the convergence value for the correction value signal
Sc, is closer to the actual temperature Sd of the intake air than
the first convergence value Ev1 for the first temperature signal
Sa1. In this instance, an error between the correction value signal
Sc and the actual temperature signal Sd is a difference between the
correction convergence value Ev3 and the actual temperature Sd, and
is smaller than a difference between the first convergence value
Ev1 and the actual temperature Sd. Moreover, the time required for
the correction value signal Sc to reach the correction convergence
value Ev3 is the same as the time Tb required for the first
correction signal Sb1 to reach the first convergence value Ev1.
Therefore, the correction value signal Sc is higher in both the
measurement accuracy and the response than the first temperature
signal Sa1.
[0457] The circuit chip 81 has a function of executing processing
of each functional block of the temperature correction unit 510. In
this case, the function of executing the processing of the
temperature correction unit 510 corresponds to a physical quantity
correction unit, the function of executing the processing of the
first correction unit 511 corresponds to a change correction unit
and the different king-quantity correction unit, and the function
of executing the processing of the second correction unit 513
corresponds to a differential correction unit.
[0458] The circuit chip 81 has a flow rate correction unit as a
function of improving the measurement accuracy of the flow rate
correction values by correcting the flow rate signals Sa3 of the
flow rate detector 22. The flow rate correction unit is
electrically connected to the intake air temperature sensor 23, and
acquires a detection signal of the intake air temperature sensor
23. The flow rate correction unit uses the detection signal of the
intake air temperature sensor 23 as a correction parameter for
correction of the flow rate signal Sa3. In this example, since the
intake air temperature sensor 23 is provided outside the housing
21, the degree of heat application from the external heat source is
likely to be smaller than that of the flow rate detector 22. This
is because, since the intake air temperature sensor 23 is exposed
to the intake passage 12, a heat is likely to be applied to the
intake air temperature sensor 23 from the intake air flowing
through the intake air passage 12, while the heat applied to the
housing 21 from an external heat source is less likely to be
transmitted to the intake air temperature sensor 23. For that
reason, the correction of the flow rate signal Sa3 is performed
with the use of the detection signal of the intake air temperature
sensor 23, which is less affected by the heat from the external
heat source, as a correction parameter, so that the correction
accuracy can be improved.
[0459] In the configuration group H, according to the present
embodiment, the second temperature detector 506 is disposed between
the housing base end face 192 and the first temperature detector
505 in the height direction Y. In that case, the degree of heat
application from the external heat source tends to be different
between the first temperature detector 505 and the second
temperature detector 506. In this instance, the first temperature
signal Sa1 can be corrected by the second temperature signal Sa2 by
leveraging the fact that the difference in degree of heat
application on the temperature detectors 505 and 506 is easily
reflected in the difference in the temperature signal Sa1 and Sa2,
which is the detection result of the temperature detectors 505 and
506. This makes it possible to improve the measurement accuracy of
the correction value signal Sc which is the temperature measurement
value.
[0460] According to the present embodiment, both the first
temperature detector 505 and the second temperature detector 506
are disposed in the inward part 501 of the air flow meter 14. For
that reason, the heat applied from the external heat source to the
temperature detectors 505 and 506 is not excessively large as
compared with the heat applied from the intake air flowing through
the intake passage 12. In other words, the difference between each
of the first temperature signal Sa1 and the second temperature
signal Sa2, and the actual temperature Sd of the intake air is not
excessively large. In this instance, since the first temperature
signal Sa1 tends to have an appropriate value as the detected value
and the second temperature signal Sa2 tends to have an appropriate
value as the correction value, the measurement accuracy of the
correction value signal Sc can be enhanced.
[0461] According to the present embodiment, both the first
temperature detector 505 and the second temperature detector 506
are included in the sensor SA 50. In this instance, the detection
board 22a, the lead frame 82, and the like in the sensor SA 50 can
be used as a circuit board for installing the temperature detectors
505 and 506, and therefore, there is no need to install a dedicated
circuit board in the housing 21. For that reason, as compared with
a configuration in which at least one of the temperature detectors
505 and 506 is not mounted on the sensor SA 50, the design load,
the cost load, and the like can be reduced.
[0462] According to the present embodiment, the air flow meter 14
includes the flow rate detector 22 in addition to the temperature
detectors 505 and 506. For that reason, the first temperature
signal Sa1 can be corrected with the use of a correction parameter
of the flow rate, which is a physical quantity different from that
of the air. For example, the flow rate signal Sa3 can be used for
correcting the first temperature signal Sa1 by leveraging the
phenomena that the convergence of the first temperature signal Sa1
to the first convergence value Ev1 is easily changed in accordance
with the flow rate signal Sa3 indicating the amount of intake air
flowing through the intake passage 12. The measurement accuracy of
the correction value signal Sc can be enhanced by the flow rate
signal Sa3.
[0463] According to the present embodiment, both the first
temperature detector 505 and the flow rate detector 22 are provided
in the measurement flow channel 32. When the circuit board on which
the first temperature detector 505 is mounted, and the circuit
board on which the flow rate detector 22 is mounted can be shared,
so that the cost burden of the sensor SA 50 can be reduced. In
addition, since both the first temperature signal Sa1 and the flow
rate signal Sa3 are intended to detect the intake air flowing
through the measurement flow channel 32, the intake air is likely
to be the same as the detection target of the first temperature
signal Sa1 and the detection target of the flow rate signal Sa3.
Therefore, in the configuration in which the first temperature
signal Sa1 to be corrected is corrected by the flow rate signal Sa3
as the correction parameter, the correction accuracy can be
enhanced.
[0464] According to the present embodiment, since the first
temperature signal Sa1 is corrected using the second temperature
signal Sa2 as a correction parameter, the correction accuracy of
the correction value signal Sc can be enhanced. In addition, since
the temperature differential signal Sb2 is used as the correction
parameter, the correction accuracy of the correction value signal
Sc can be enhanced by using a relatively changing mode of the
second temperature signal Sa2 to the first temperature signal
Sa1.
[0465] According to the present embodiment, correction of the
temperature differential signal Sb2 is performed so that as the
temperature differential signal Sb2 is larger, the differential
correction signal Sb3 is larger. For that reason, the error of the
correction value signal Sc with respect to the actual temperature
Sd of the intake air can be reduced more than the error of the
first temperature signal Sa1 with respect to the actual temperature
Sd. In other words, the measurement accuracy of the correction
value signal Sc can be enhanced.
[0466] According to the present embodiment, the flow rate signal
Sa3 is used to correct the first temperature signal Sa1 together
with the second temperature signal Sa2. For that reason, the second
temperature signal Sa2 can improve the measurement accuracy of the
correction value signal Sc, while the flow rate signal Sa3 can
improve the response of the correction value signal Sc.
[0467] According to the present embodiment, the temperature is
detected as the same kind of physical quantity by the two
detectors, that is, the first temperature detector 505 and the
second temperature detector 506. For that reason, the first
temperature signal Sa1 can be corrected with high accuracy after
the degree of heat application from the external heat source is
properly grasped by the temperature signals Sa1 and Sa2. In other
words, the measurement accuracy of the correction value signal Sc
can be enhanced.
[0468] According to the present embodiment, the first temperature
signal Sa1 is corrected based on the behavior of change of the
first temperature signal Sa1. Since a future value of the first
temperature signal Sa1 can be predicted, a time required for the
first correction signal Sb1 to reach the first convergence value
Ev1 can be shortened more than a time required for the first
temperature signal Sa1 to reach the first convergence value Ev1.
Therefore, the response of the correction value signal Sc can be
enhanced. Moreover, both of the behavior of change of the first
temperature signal Sa1 and the second temperature signal Sa2 are
used for the first temperature signal Sa1, thereby being capable of
enhancing both of the response and the measurement accuracy of the
correction value signal Sc.
[0469] According to the present embodiment, the flow rate signal
Sa3 is used for correcting the first temperature signal Sa1
together with the behavior of change of the first temperature
signal Sa1. For that reason, the response of the correction value
signal Sc enhanced by the behavior of change of the first
temperature signal Sa1 can be further enhanced by the flow rate
signal Sa3. In addition, since the behavior of change of the first
temperature signal Sa1 is used for the correction of the second
temperature signal Sa2 together with the second temperature signal
Sa2, the response of the correction value signal Sc, which is less
likely to be improved by the second temperature signal Sa2, can be
enhanced.
[0470] According to the present embodiment, as the flow rate signal
Sa3 is smaller, the correction amount signal Sb5 is larger. For
that reason, the response of the correction value signal Sc can be
enhanced by leveraging the phenomena that the response of the first
temperature signal Sa1 tends to decrease more as the flow rate of
the intake air decreases more, for example, when the flow velocity
of the intake air in the intake passage 12 is smaller.
Second Embodiment
[0471] In the first embodiment, the shape of the longitudinal
partition wall 69 is set irrespective of the shape of the detection
throttle portion 59, but in a second embodiment, a shape of a
longitudinal partition wall 69 is set according to a shape of a
detection throttle portion 59. In the present embodiment,
differences from the first embodiment will be mainly described.
[0472] As shown in FIGS. 58 and 59, the longitudinal partition wall
69 has a wall main body 69a and a wall bulging portion 69b. The
wall main body 69a and the wall bulging portion 69b are aligned in
the width direction X, and the wall bulging portion 69b is arranged
on a front side of a sensor SA 50 in the width direction X. The
wall bulging portion 69b extends from the detection throttle
portion 59 toward a housing tip side in the height direction Y, and
has the same shape as the shape of a portion of the detection
throttle portion 59 on a front side of the wall main body 69a.
[0473] In the depth direction Z, a depth dimension D9 of the wall
main body 69a is smaller than a depth dimension D1 of the detection
throttle portion 59, and a depth dimension D10 of the wall bulging
portion 69b is the same as or larger than the depth dimension D1 of
the detection throttle portion 59. Also, in the present embodiment,
when it is assumed that the longitudinal partition wall 69 and the
detection throttle portion 59 are integral parts, even if the part
as a whole comes closer to a housing opening 61, the part does not
become thick. For that reason, at the time of molding the housing
21 with resin, an inward portion 93 of an inner peripheral mold
portion 91 that enters an internal space 24a can be removed from
the detection throttle portion 59 and the longitudinal partition
wall 69, and the inward portion 93 can be extracted from the
housing opening 61.
Third Embodiment
[0474] In the first embodiment, the width housing protrusion 72a of
the housing body 24 is provided at a position facing the front
surface of the sensor SA 50, whereas in a third embodiment, a width
housing protrusion 72a is provided at a position facing a back
surface of a sensor SA 50. In the present embodiment, differences
from the first embodiment will be mainly described.
[0475] As shown in FIG. 60, the width housing protrusion 72a abuts
against a back SA protrusion 71b, not a front SA protrusion 71a of
the sensor SA 50. For that reason, the front SA protrusion 71a of
the sensor SA 50 abuts against a front surface of an inner
peripheral surface of a housing body 24. In FIG. 60, a flow rate
detector 22 is exposed on a left side surface of the sensor SA 50,
and the left side surface is referred to as a front surface, and a
right side surface is referred to as a back surface. On the other
hand, in FIG. 14 of the first embodiment, the flow rate detector 22
is exposed on the right side surface of the sensor SA 50, and the
right side surface is referred to as the front surface, and the
left side surface is referred to as the back surface.
[0476] In the present embodiment, as described above, since the
front SA protrusion 71a abuts against the front surface of the
inner peripheral surface of the housing body 24, a separation
distance between the front surface and the flow rate detector 22 is
defined by a protrusion dimension of the front SA protrusion 71a.
In other words, the separation distance between the inner
peripheral surface of the detection path 32a and the flow rate
detector 22 is defined regardless of the width housing protrusion
72a. For that reason, even in a configuration in which the back SA
protrusion 71b deforms the width housing protrusion 72a with the
insertion of the sensor SA 50 into the internal space 24a, the
separation distance between the inner peripheral surface of the
detection path 32a and the flow rate detector 22 is set regardless
of the degree of deformation of the width housing protrusion 72a.
In this case, since a manufacturing variation hardly occurs in the
separation distance between the inner peripheral surface of the
detection path 32a and the flow rate detector 22, the detection
accuracy by the flow rate detector 22 can be inhibited from varying
from product to product.
[0477] In addition, a depth housing protrusion 72b of the present
embodiment is provided at a position facing the sensor SA 50 in the
downstream-side outer peripheral portion of the housing body 24,
not the upstream-side outer peripheral portion. The depth housing
protrusion 72b extends toward a curved surface 45 of the housing
body 24 in a direction inclined with respect to the depth direction
Z. In the above configuration, the sensor SA 50 is pressed against
the curved surface 45 in the internal space 24a by the deformation
of the depth housing protrusion 72b pressed by the end face of a
junction portion 52 of the sensor SA 50. As a result, the
positioning accuracy of the sensor SA 50 with respect to the
housing 21 can be enhanced in the depth direction Z as well.
Fourth Embodiment
[0478] In the first embodiment, the housing opening 61 is opened in
the height direction Y, but in the fourth embodiment, a housing
opening 61 is opened in the width direction X. In the present
embodiment, an air flow meter 200 is included in a combustion
system instead of the air flow meter 14 as the physical quantity
measurement device, and differences from the first embodiment will
be mainly described.
[0479] As shown in FIGS. 61 and 62, the air flow meter 200 is
provided in the intake passage 12. The air flow meter 200 is a
physical quantity measurement device similar to the air flow meter
14 of the first embodiment, and is attached to an intake pipe 12a
(refer to FIGS. 2 and 8). The air flow meter 200 includes a housing
201, a flow rate detector 202, and a sealing member 206, and the
housing 201 includes a housing body 204, a sealing holder 205, a
flange portion 207, and a connector portion 208. Those members and
parts correspond to members and parts having the same names as
those of the first embodiment.
[0480] In the housing 201, one end face is referred to as a housing
tip end face 215, the other end face is referred to as a housing
base end face 216, and further, in the height direction Y, the
housing tip end face 215 side is referred to as a housing tip side,
and the housing base end face 216 side is referred to as a housing
base end side. In the present embodiment, the housing body 204, the
sealing holder 205, the flange portion 207, and the connector
portion 208 are arrayed in the stated order from the housing tip
side, and the housing body 204 extends from the sealing holder 205
toward the housing tip side. In the air flow meter 200, the housing
body 204 and a part of the sealing holder 205 are included in the
inward part which enters the interior of the intake pipe 12a, and
the housing tip end face 215 is further included in the inward
portion. A part of the sealing holder 205, the flange portion 207,
and the connector portion 208 are included in an outward part
protruding to the outside of the intake pipe 12a, and a housing
base end face 216 is further included in the protrusion portion. In
this case, in the housing 201, the housing base end face 216 may be
referred to as an end portion on the outward part side, and the
housing tip end face 215 may be referred to as an end portion on
the inward part side.
[0481] The sealing member 206 is provided between the sealing
holder 205 and a pipe flange 12c of an intake pipe 12a, and is in
close contact with the sealing holder 205 and the pipe flange 12c.
Like an O-ring 26 of the first embodiment, the sealing member 206
is a member that restricts an intake air from leaking out of an
airflow insertion hole 12b, and is formed in a rectangular annular
shape in accordance with the shape of the sealing holder 205. In
this case, an outer peripheral end of the sealing member 206 has a
rectangular shape. In the present embodiment, while the sealing
holder 205 does not have a groove portion, the flange portion 207
extends from the sealing holder 205 toward the outer peripheral
side, and the sealing member 206 is also pressed against the flange
portion 207. For that reason, even if the sealing holder 205 itself
does not have a function of holding the sealing member 206, the
sealing holder 205 and the flange portion 207 can hold the sealing
member 206. In this case, the sealing member 206 may be referred to
as a pressing packing.
[0482] The housing body 204 has a bypass flow channel 210. The
bypass flow channel has a passage flow channel 211, a measurement
flow channel 212, an inflow port 213a, an outflow port 213b, and a
measurement outlet 213c. The flow rate detector 202 is included in
the sensor SA 220. Those members and parts correspond to members
and parts having the same names as those of the first embodiment.
The sensor SA 220 includes an SA base portion 221, a detection
support portion 223, and lead terminals 224 (refer to FIG. 63). The
detection support portion 223 supports the flow rate detector 202,
and the SA base portion 221 supports the detection support portion
223 and the lead terminals 224. The SA base portion 221 corresponds
to the circuit accommodation portion 51 and the junction portion 52
of the first embodiment, and the detection support portion 223 and
the lead terminals 224 are members or portions corresponding to the
sensing portion 53 and the lead terminals 54. The sensor SA 220 may
be referred to as a sensor module, a sensor assembly, or a sensor
unit.
[0483] In the sensor SA 220, the flow rate detector 202, the SA
base portion 221, and the detection support portion 223 configure
an SA main body 225. In this instance, the sensor SA 220 includes
an SA main body 225 and the lead terminals 224. In the sensor SA
220, the SA main body 225 is a portion having the flow rate
detector 202, and the lead terminals 224 extend from the SA main
body 225.
[0484] The detection support portion 223 extends from the SA base
portion 221 toward the housing tip side, and the lead terminals 224
extend from the SA base portion 221 toward the housing base end
side. The detection support portion 223 has a size and a shape
capable of placing the flow rate detector 202 in the measurement
flow channel 212, and the lead terminals 224 are electrically
connected to connector terminals 208a (refer to FIG. 63) provided
in the connector portion 208. Similarly to the connector terminals
28a of the first embodiment, the connector terminal 208a is
electrically connected to the ECU 20 by inserting a plug portion
into the connector portion 208.
[0485] The housing body 204 has an internal space 204a in which the
sensor SA 220 is accommodated, and a housing opening 241 in which
the internal space 204a is opened. The housing body 204 has wall
portions 231 to 235 defining the internal space 204a, and those
wall portions 231 to 235 are all plate-shaped. The upstream wall
portion 231 on the upstream side of the internal space 204a and the
downstream wall portion 232 on the downstream side of the internal
space 204a are aligned in the depth direction Z, and are opposed to
each other across the internal space 204a in a state in which the
plate surfaces of the upstream wall portion 231 and the downstream
wall portion 232 are directed in the depth direction Z. The front
wall portion 233 opposed to the front surface of the sensor SA 220
and the back wall portion 234 opposed to the back surface of the
sensor SA 220 are aligned in the width direction X, and are opposed
to each other across the internal space 204a in a state where the
respective plate surfaces of the front wall portion 233 and the
back wall portion 234 are directed in the width direction X.
[0486] A tip wall portion 235 forms a tip end face of the housing
body 204, and connects the wall portions 231 to 234 to each other.
The tip wall portion 235 extends over the front wall portion 233
and the back wall portion 234 in the width direction X, and extends
over the upstream wall portion 231 and the downstream wall portion
232 in the depth direction Z.
[0487] An opening direction of the housing opening 241 is different
from an opening direction of the housing opening 61 of the first
embodiment, and coincides with the width direction X. The housing
opening 241 is defined in the front wall portion 233. The housing
opening 241 is provided at a position closer to the sealing holder
205 in the height direction Y, and extends from the sealing holder
205 toward the housing tip side. In that case, the upstream wall
portion 231, the downstream wall portion 232, and the back wall
portion 234 extend from the sealing holder 205 toward the housing
tip side, while the back wall portion 234 is disposed at a position
spaced apart from the sealing holder 205 toward the housing tip
side.
[0488] In the housing body 204, an inflow port 213a is provided in
the upstream wall portion 231, an outflow port 213b is provided in
the downstream wall portion 232, and a measurement outlet 213c is
provided in each of the front wall portion 233 and the back wall
portion 234.
[0489] The air flow meter 200 includes a potting portion 242 that
closes the housing opening 241. The potting portion 242 covers the
sensor SA 220 from the housing opening 241, and corresponds to a
cover portion. The potting portion 242 is formed by curing a
thermosetting resin such as a potting resin filled in the internal
space 204a, similarly to the potting portion 65 of the first
embodiment. The thermosetting resin is injected into the internal
space 204a from the housing opening 241 in a fluid state to seal
the internal space 204a. As in the first embodiment, the
thermosetting resin may be formed of an epoxy resin, a urethane
resin, a silicon resin, or the like.
[0490] The sensor SA 220 is held in position so as not to be
displaced in the internal space 204a. As shown in FIGS. 63 and 64,
the housing body 204 includes regulation portions 251 and 255 for
regulating positional deviation of the sensor SA 220. Each of the
regulation portions 251 and 255 is formed in a plate shape, and is
provided at a predetermined interval in the height direction Yin a
state in which each plate surface of the regulation portions 251
and 255 is directed in the height direction Y. The regulation
portions 251 and 255 are provided at an intermediate position of
the housing body 204 in the height direction Y.
[0491] The regulation portions 251 and 255 are opposed to each
other, and the sensor SA 220 is inserted between the regulation
portions 251 and 255. The SA base portion 221 of the sensor SA 220
is fitted between the regulation portions 251 and 255, and the SA
base portion 221 is caught by the regulation portions 251 and 251,
thereby regulating the sensor SA 220 from moving in the height
direction Y. The first regulation portion 251 is provided on the
housing tip side of the SA base portion 221, and the second
regulation portion 255 is provided on the housing base end side of
the SA base portion 221. The sensor SA 220 is hardly moved in the
width direction X and the depth direction Z because the SA base
portion 221 is sandwiched between the regulation portions 251 and
255.
[0492] The internal space 204a has a flow channel region QA
defining the bypass flow channel 210 (refer to FIG. 61), a support
region QB accommodating the SA base portion 221, and a connector
region QC accommodating connection portions between the connector
terminals 208a and the lead terminals 224. In the height direction
Y, the support region QB is disposed between the flow channel
region QA and the connector region QC. The flow channel region QA
and the support region QB are separated by the first regulation
portion 251, and the support region QB and the connector region QC
are separated by the second regulation portion 255. An end face of
the sealing holder 205 on the housing base end side faces the
second regulation portion 255 across the connector region QC, and
the connector region QC is also partitioned by those sealing
holders 205. In the height direction Y, a boundary between the flow
channel region QA and the support region QB is disposed at the
center of the first regulation portion 251, and a boundary between
the support region QB and the connector region QC is disposed at
the center of the second regulation portion 255.
[0493] The potting portion 242 is not filled in all regions of the
internal space 204a, but is filled in the support region QB and the
connector region QC, but is not filled in the flow channel region
QA. The support region QB and the connector region QC are regions
opened to the outside through the housing opening 241, and the
operator can inject the thermosetting resin from the housing
opening 241 into the support region QB and the connector region
QC.
[0494] The first regulation portion 251 is provided between the
front wall portion 233 and the back wall portion 234 in the width
direction X, and extends over the wall portions 233 and 234. The
first regulation portion 251 is provided between the upstream wall
portion 231 and the downstream wall portion 232 in the depth
direction Z, and extends over the wall portions 231 and 232. The
first regulation portion 251 is provided with a first insertion
portion 252 through which the detection support portion 223 of the
sensor SA 220 is inserted. The first insertion portion 252 is a
notch that penetrates through the first regulation portion 251 in
the height direction Y, and extends from the front end portion of
the first regulation portion 251 toward the back wall portion 234
at an intermediate position of the first regulation portion 251 in
the depth direction Z. The first insertion portion 252 may be a
through hole penetrating through the first regulation portion
251.
[0495] The sensor SA 220 and the first regulation portion 251 are
in close contact with each other so that the thermosetting resin
injected into the support region QB and the connector region QC
does not leak into the flow channel region QA from between the
sensor SA 220 and the first regulation portion 251 at the time of
manufacturing the air flow meter 200. Specifically, an end face of
the SA base portion 221 on the housing tip side and an outer
peripheral surface of the first regulation portion 251 abut against
each other so as to overlap with each other, and an inner
peripheral surface of the first insertion portion 252 and an outer
peripheral surface of the detection support portion 223 abut
against each other so as to overlap with each other. In addition,
because the SA base portion 221 and the front wall portion 233 are
in contact with each other, the thermosetting resin is prevented
from leaking from a gap between the detection support portion 223
and the front wall portion 233.
[0496] Like the first regulation portion 251, the second regulation
portion 255 is provided between the upstream wall portion 231 and
the downstream wall portion 232 in the depth direction Z, and
extends over the wall portions 231 and 232. On the other hand,
unlike the first regulation portion 251, the second regulation
portion 255 extends from the back wall portion 234 toward the
housing opening 241 in the width direction X, and is not connected
to the front wall portion 233. The second regulation portion 255 is
provided with a second insertion portion 256 through which the lead
terminals 224 of the sensor SA 220 are inserted. The second
insertion portion 256 is a notch that penetrates through the second
regulation portion 255 in the height direction Y, and extends from
the front end portion of the second regulation portion 255 toward
the back wall portion 234 at an intermediate position of the second
regulation portion 255 in the depth direction Z.
[0497] In the second regulation portion 255, as described above,
the SA base portion 221 comes in contact with the second regulation
portion 255, thereby regulating the sensor SA 220 from moving
toward the housing base end side. The SA base portion 221 is
sandwiched between the front wall portion 233 and the back wall
portion 234. In this instance, the front surface of the SA base
portion 221 comes in contact with the front wall portion 233, and
the back surface of the SA base portion 221 comes in contact with
the back wall portion 234, thereby regulating the sensor SA 220
from moving in the width direction X.
[0498] The back wall portion 234 is provided with an accommodating
recess portion 264 for accommodating the back plate surface of the
SA base portion 221. The accommodating recess portion 264 is
defined by recessing the inner peripheral surface of the back wall
portion 234 toward the outer peripheral side, and is disposed at an
intermediate position between the upstream wall portion 231 and the
downstream wall portion 232 in the depth direction Z. The SA base
portion 221 is fitted in the accommodating recess portion 264, and
the inner peripheral surface of the accommodating recess portion
264 regulates the sensor SA 220 from moving in the depth direction
Z.
[0499] Unlike the housing 21 of the first embodiment, the housing
201 is formed by assembling multiple components together. The
housing 201 includes a base member 261 and a cover member 262. The
cover member 262 has at least a front wall portion 233 of the
housing body 204, and is integrally molded as a member separate
from the base member 261. The base member 261 includes a portion of
the housing body 204 excluding the cover member 262, a sealing
holder 205, a flange portion 207, and a connector portion 208, and
those portions are integrally molded.
[0500] An internal space of the base member 261 is opened toward a
side opposite to the back wall portion 234 across the upstream wall
portion 231, the downstream wall portion 232, and the tip wall
portion 235, because the base member 261 does not have the front
wall portion 233. When the open portion is referred to as a base
opening 263, the base opening 263 is closed by the cover member 262
and the potting portion 242 in a state where the housing 201 is
completed.
[0501] An accommodation notch portion 265 accommodating the cover
member 262 is provided in the base member 261 so that a step does
not occur at the boundary between the base member 261 and the cover
member 262 on the surface of the housing body 204. The
accommodation notch portion 265 extends over the upstream wall
portion 231, the downstream wall portion 232, the tip wall portion
235, and the first regulation portion 251, and notches the front
end portion of the base member 261. Since the cover member 262
enters the accommodation notch portion 265, a portion formed by the
upstream wall portion 231 and the downstream wall portion 232 and a
portion formed by the cover member 262 are flush with each other on
the surface of the housing body 204.
[0502] In the present embodiment, the flow rate detector 202
corresponds to a physical quantity detector, and the sensor SA 220
corresponds to a detection unit. In FIG. 63, FIG. 64, and the like,
illustration of the bypass flow channel 210 is omitted. FIG. 63 is
a partial cross-sectional view showing a cross section of only a
portion of the housing 201 closer to the housing tip side than the
sealing holder 205. FIG. 64 is a view of the housing 201 seen from
the open side of the base member 261 in a state where the potting
portion 242 and the cover member 262 are removed.
[0503] Next, referring to FIGS. 65 to 68, a manufacturing method of
the air flow meter 200 will be described focusing on a procedure of
mounting the sensor SA 220 to the housing 201.
[0504] In the housing body 204, the base member 261 and the cover
member 262 are produced by performing resin molding. In the
production of the base member 261, the base member 261, which is in
a state where the connector terminals 208a are embedded, is molded
with resin by temporarily detachably attaching the connector
terminals 208a to a mold device such as a mold, and injecting
molten resin into the mold device in this state, thereby molding
the base member 261. When the mold device is to be removed from the
base member 261, the temporary attachment of the connector
terminals 208a to the mold device is released, and the mold device
is removed from the base member 261. In the resin-molded base
member 261, as shown in FIG. 65, one end portions of the connector
terminals 208a protrude from the sealing holder 205 toward the
housing tip side.
[0505] Then, as shown in FIG. 66, the cover member 262 is attached
to the base member 261 so that a part of the base opening 263 is
closed with the cover member 262. As a result, the housing 201, the
housing body 204, and the housing opening 241 are produced. In this
example, the base member 261 and the cover member 262 are joined to
each other by bonding or welding in a portion where the base member
261 and the cover member 262 are in contact with each other.
[0506] Subsequently, as shown in FIG. 67, the sensor SA 220 is
attached to the housing body 204 by inserting the sensor SA 220
into the internal space 204a from the housing opening 241. In this
example, the sensor SA 220 is pushed in such a manner that the SA
base portion 221 is fitted between the first regulation portion 251
and the second regulation portion 255 while the detection support
portion 223 is inserted into the first insertion portion 252, and
the SA base portion 221 is also fitted into the accommodating
recess portion 264. Thereafter, the lead terminals 224 and the
connector terminals 208a are electrically connected to each other
by welding or the like.
[0507] As shown in FIG. 68, after the housing body 204 has been
completed by assembling the cover member 262 to the base member
261, the thermosetting resin in a fluid state is injected from the
housing opening 241 into the support region QB and the connector
region QC. The support region QB and the connector region QC are
filled with the thermosetting resin so that the connector terminals
208a, the lead terminals 224, and the sensor SA 220 are not exposed
from the housing opening 241. Thereafter, the thermosetting resin
is cured by heating to form the potting portion 242.
[0508] <Description of Configuration Group C>
[0509] The configuration group C relating to the positional
relationship between the housing attachment and the position holder
will be described with reference to FIGS. 61 to 64, 69 to 71, and
the like. In FIG. 69, the upstream wall portion 231, the downstream
wall portion 232, the front wall portion 233, and the back wall
portion 234 of the base member 261 of the housing body 204 are not
illustrated.
[0510] In FIGS. 61 to 64, the sealing holder 205 is thicker than
the housing body 204. In the sealing holder 205, like the ring
holding portion 25 of the first embodiment, the outer peripheral
end of the lateral cross section is circular, while the housing
body 204 extending from the end face of the sealing holder 205 on
the housing tip side is rectangular in lateral cross section. The
sealing holder 205 is thick so as to be able to secure a strength
necessary for supporting the air flow meter 200. In the housing
201, the housing attachment attached to the intake pipe 12a
includes the sealing holder 205 and the flange portion 207.
[0511] As described above, in the housing body 204, the first
regulation portion 251 and the second regulation portion 255
regulate the movement of the sensor SA 220, and each of the
regulation portions 251 and 255 corresponds to a position holder.
In the housing body 204, the upstream wall portion 231, the
downstream wall portion 232, and the back wall portion 234 connect
the sealing holder 205 and the regulation portions 251 and 255, and
those wall portions 231, 232, and 234 correspond to a housing
connector. The internal space 204a corresponds to an accommodation
space in which the sensor SA 220 is accommodated.
[0512] In the first regulation portion 251, the plate surface 251a
on the housing base end side comes in contact with the SA base
portion 221, and the plate surface 251 regulates the sensor SA 220
from moving toward the housing tip side. In the second regulation
portion 255, the plate surface 255a on the housing tip side comes
in contact with the SA base portion 221, and the plate surface 255a
regulates the sensor SA 220 from moving toward the housing base end
side. In this instance, the plate surfaces 251a and 255a are
positioned and held so that the sensor SA 220 does not move in the
height direction Y, and in particular, the plate surface 251a of
the first regulation portion 251 corresponds to a third holding
portion.
[0513] In the SA base portion 221, the end face 221a on the housing
tip side comes in contact with the plate surface 251a of the first
regulation portion 251, and the end face 221b on the housing base
end side comes in contact with the plate surface 255a of the second
regulation portion 255. In this case, the end faces 221a and 221b
of the SA base portion 221 correspond to a unit contact portion
that is in contact with the third holding portion.
[0514] As described above, since the outer peripheral surface of
the detection support portion 223 comes in contact with the inner
peripheral surface of the first insertion portion 252, the sensor
SA 220 is regulated from moving in the width direction X and the
depth direction Z. As shown in FIG. 69, the inner peripheral
surface of the first insertion portion 252 includes a front inner
surface 252a, a back inner surface 252b, an upstream inner surface
252c, and a downstream inner surface 252d.
[0515] The front inner surface 252a and the back inner surface 252b
are aligned in the width direction X, and the front inner surface
252a comes in contact with the front surface of the detection
support portion 223, and the back inner surface 252b comes in
contact with the back surface of the detection support portion 223.
The front inner surface 252a and the back inner surface 252b hold
the sensor SA 220 in position so as not to move in the width
direction X, and correspond to a first holding portion. The
upstream inner surface 252c and the downstream inner surface 252d
are aligned in the depth direction Z, the upstream inner surface
252c is disposed on the upstream wall portion 231 side of the
housing body 204, and the downstream inner surface 252d is disposed
on the downstream wall portion 232 side. Both of the upstream inner
surface 252c and the downstream inner surface 252d are in contact
with the side surface of the detection support portion 223, so that
the sensor SA 220 is held in position so as not to move in the
depth direction Z, and correspond to a second holding portion.
[0516] In the present embodiment, as in the first embodiment, the
width direction X corresponds to a first direction, and the depth
direction Z corresponds to a second direction. The plate surface
251a of the first regulation portion 251 and the inner surfaces
252a to 252d of the first insertion portion 252 may also be
referred to as positioning surfaces.
[0517] As shown in FIGS. 70 and 71, the housing body 204 has
throttle portions 271 and 272 for throttling the measurement flow
channel 212 by reducing a flow channel area of the measurement flow
channel 212. The front throttle portion 271 is a projection portion
extending from the front wall portion 233 toward the back wall
portion 234, and the back throttle portion 272 is a projection
portion extending from the back wall portion 234 toward the front
wall portion 233. The front throttle portion 271 and the back
throttle portion 272 face each other across the detection support
portion 223, and the flow rate detector 202 is disposed between the
throttle portions 271 and 272. In this case, the flow rate detector
202 faces the front throttle portion 271.
[0518] In the measurement flow channel 212, a region around the
flow rate detector 202 is narrowed by the throttle portions 271 and
272, so that the intake air reaching the flow rate detector 202 is
regulated. In this case, turbulence is less likely to occur in the
flow of the intake air in the vicinity of the flow rate detector
202, and the detection accuracy of the flow rate detector 202 can
be inhibited from being lowered due to the turbulence. Like the
flow rate detector 22 of the first embodiment, the flow rate
detector 202 is a detector using the heat radiation amount of the
heat generation portion, and it is preferable that the flow rate of
the intake air in the vicinity of the flow rate detector 202 is
large to some extent in order to keep the detection accuracy of the
flow rate detector 202 appropriate. On the other hand, in the
present embodiment, since the flow velocity of the intake air tends
to increase because the measurement flow channel 212 is narrowed by
the throttle portions 271 and 272 toward the flow rate detector
202, the detection accuracy of the flow rate detector 202 can be
optimized.
[0519] When a portion of the front wall portion 233 where the front
throttle portion 271 is formed is referred to as a front forming
portion 233a, the front forming portion 233a is thicker than other
portions of the front wall portion 233. Similarly, a portion of the
back wall portion 234 where the back throttle portion 272 is formed
is referred to as a back forming portion 234a, and the back forming
portion 234a is thicker than other portions of the back wall
portion 234.
[0520] In this example, in the back wall portion 234, there is a
concern that the deformation caused by the resin molding may occur
in the back forming portion 234a at the time of manufacturing the
air flow meter 200 since the back forming portion 234a is thick. On
the other hand, in the base member 261 in which the back wall
portion 234 and the first regulation portion 251 are integrally
molded, the back throttle portion 272 is separated from the first
regulation portion 251 toward the housing tip side in the height
direction Y. In this case, even if the deformation caused by the
resin molding occurs in the back forming portion 234a, it is
considered that the deformation is absorbed in a portion between
the first regulation portion 251 and the back forming portion 234a
in the back wall portion 234. For that reason, the position and
shape of the first regulation portion 251 are less likely to change
with the deformation of the back forming portion 234a, as a result
of which, the positional deviation of the flow rate detector 202 is
reduced.
[0521] In the housing body 204, the front forming portion 233a is
thicker than the back forming portion 234a. In this case, in the
width direction X, a protrusion dimension D31 of the front throttle
portion 271 from the front wall portion 233 is larger than a
protrusion dimension D32 of the back throttle portion 272 from the
back wall portion 234. For that reason, even if the front forming
portion 233a is thinned as much as possible so as not to be
deformed by the resin molding, the degree of throttling of the
measurement flow channel 212 can be appropriately increased so that
the detection accuracy of the flow rate detector 202 can be
optimized by adjusting the thickness of the front forming portion
233a. As described above, the cover member 262 having the front
forming portion 233a and the base member 261 having the first
regulation portion 251 are separate members. In this case, even if
the deformation attributable to the resin molding occurs in the
front forming portion 233a, the position and shape of the first
regulation portion 251 do not change due to the deformation, and
therefore, the positional deviation of the flow rate detector 202
does not occur due to the thickness increase of the front forming
portion 233a.
[0522] In the width direction X, a separation distance D33 between
the front surface of the detection support portion 223 and the
front throttle portion 271 is smaller than a separation distance
D34 between the back surface of the detection support portion 223
and the back throttle portion 272. In the measurement flow channel
212, a region between the detection support portion 223 and the
front throttle portion 271 has a larger degree of throttling than a
region between the detection support portion 223 and the back
throttle portion 272. If the measurement flow channel 212 is
narrowed by the front throttle portion 271, the back throttle
portion 272 is not necessarily provided.
[0523] In the configuration group C, according to the present
embodiment, in the housing 201, the first regulation portion 251
and the second regulation portion 255 are separated from the
sealing holder 205 toward the housing tip side. For that reason,
the thickness of the sealing holder 205 can be increased to improve
the strength, while the thickness of the regulation portions 251
and 255 can be reduced. Since the thinning of the regulation
portions 251 and 255 is achieved in this manner, the shapes of the
regulation portions 251 and 255 are less likely to vary from
product to product, so that the position of the sensor SA 220
positioned by the regulation portions 251 and 255 is less likely to
vary. Therefore, the detection accuracy of the flow rate detector
202 can be inhibited from varying from product to product.
[0524] According to the present embodiment, in the first regulation
portion 251, the front inner surface 252a and the back inner
surface 252b regulate the movement of the sensor SA 220 in the
width direction X, and the upstream inner surface 252c and the
downstream inner surface 252d regulate the movement of the sensor
SA 220 in the depth direction Z. In this instance, in the first
regulation portion 251, since the deformation caused by the resin
molding is hardly generated in those inner surfaces 252a to 252d,
the position of the sensor SA 220 in the width direction X and the
depth direction Z can be inhibited from varying from product to
product.
[0525] According to the present embodiment, in the first regulation
portion 251, the plate surface 251a on the housing base end side
regulates the movement of the sensor SA 220 toward the housing tip
side. In this instance, in the first regulation portion 251, the
plate surface 251a is also less likely to be deformed due to
resin-molding, so that the position of the sensor SA 220 in the
height direction Y can be inhibited from varying from product to
product.
[0526] According to the present embodiment, in the sensor SA 220,
the end face 221a at the housing tip side is provided between the
lead terminals 224 and the flow rate detector 202 at a position
closer to the flow rate detector 202. In this instance, even if the
position of the sensor SA 220 is deviated so as to rotate about the
contact portion with the first regulation portion 251 as a fulcrum,
the amount of positional deviation of the flow rate detector 202
can be reduced as compared with a configuration in which the end
face 221a is provided at a position closer to the lead terminals
224, for example. For that reason, the detection accuracy of the
flow rate detector 202 can be inhibited from being
deteriorated.
[0527] According to the present embodiment, since the sealing
holder 205 is connected to the first regulation portion 251 and the
second regulation portion 255 by the upstream wall portion 231, the
downstream wall portion 232, and the back wall portion 234, a
configuration can be realized in which the sealing holder 205 is
separated from the regulation portions 251 and 255. In this case,
even if the deformation caused by the resin molding occurs in the
sealing holder 205, the deformation is absorbed by the wall
portions 231, 232, and 234, so that the positions and shapes of the
regulation portions 251 and 255 are less likely to change with the
deformation of the sealing holder 205. For that reason, the
positioning accuracy of the sensor SA 220 by the regulation
portions 251 and 255 can be inhibited from being deteriorated.
[0528] According to the present embodiment, at the time of
manufacturing the air flow meter 200, the sensor SA 220 is inserted
into the base member 261 through the base opening 263. When the
sensor SA 220 is attached to the base member 261 in this manner,
the first regulation portion 251 of the base member 261 is less
likely to be deformed by the resin molding, so that the positioning
accuracy of the sensor SA 220 by the first regulation portion 251
can be improved.
[0529] <Description of Configuration Group E>
[0530] A configuration group E relating to the position of the
connector terminals will be described with reference to FIG. 72 and
the like.
[0531] As shown in FIG. 72, the connector terminals 208a extend
between the connector portion 208 and the internal space 204a. The
connector terminals 208a each include a first terminal portion 282a
disposed in the connector portion 208, a second terminal portion
282b disposed in the internal space 204a, and a connection terminal
portion 282c connecting the terminal portions 282a and 282b. In the
connector terminal 208a, one end portion is included in the first
terminal portion 282a, and the other end portion is included in the
second terminal portion 282b. The first terminal portion 282a
extends in the connector portion 208 in a direction away from the
housing body 204. The second terminal portion 282b extends away
from the connector portion 208 in the internal space 24a. The
second terminal portion 282b is disposed between the housing
opening 241 and the back wall portion 234.
[0532] In the connector terminal 208a, at least the connection
terminal portion 282c is embedded in the housing 201. The connector
terminal 208a is fixed to the housing 201 by the embedded portion.
The connector terminal 208a does not protrude into the support
region QB, and the entire second terminal portion 282b is
accommodated in the connector region QC.
[0533] In the present embodiment, the second terminal portion 282b
corresponds to a protrusion terminal portion. In the sensor SA 220,
the lead terminal 224 corresponds to a detection terminal, and the
SA main body 225 corresponds to a unit main body. The width
direction X corresponds to a direction in which the detection unit
and the housing opening are aligned.
[0534] In the sensor SA 220, the SA main body 225 is disposed at a
position extending across the flow channel region QA and the
support region QB in the height direction Y, and the lead terminals
224 are disposed at a position extending over a boundary between
the support region QB and the connector region QC in the height
direction Y. In this case, the flow channel region QA and the
support region QB configure the main body region.
[0535] The lead terminals 224 and the connector terminal 208a are
connected to each other in the connector region QC, and in the
connection portion, the connector terminals 208a do not enter
between the lead terminals 224 and the housing opening 241 in the
width direction X. For example, in the connection portion, the lead
terminals 224 are disposed between the connector terminals 208a and
the housing opening 61 in the width direction X. The lead terminals
224 and the connector terminal 208a may be aligned laterally in the
depth direction Z. In both cases, the connector terminals 208a do
not enter the internal space 204a between the sensor SA 220 and the
housing opening 241 in the width direction X.
[0536] Next, a manufacturing method of the air flow meter 200 will
be described with reference to FIG. 72, center on the fact that the
lead terminals 224 and the connector terminals 208a are directly
connected to each other.
[0537] After the cover member 262 has been attached to the housing
201 molded with resin, the sensor SA 220 is inserted into the
internal space 204a through the housing opening 241. In this
example, the sensor SA 220 is pushed into the internal space 204a
until the SA main body 225 is caught by the back wall portion 234
or the first regulation portion 251. In this example, it is assumed
that the lead terminals 224 come into contact with the connector
terminals 208a before the SA main body 225 is caught by the back
wall portion 234 or the first regulation portion 251. On the other
hand, at least one of the lead terminals 224 and the connector
terminals 208a are deformed, so that the sensor SA 220 can be
pushed into the internal space 204a further deeply. For that
reason, even if the lead terminals 224 are disposed at the
positions extending across the boundary between the flow channel
region QA and the support region QB, the positional deviation of
the sensor SA 220 is inhibited from occurring due to the lead
terminals 224 being caught by the connector terminals 208a.
[0538] After the sensor SA 220 has been installed in the internal
space 204a, a step of connecting the lead terminals 224 and the
connector terminals 208a with the use of a joining tool is
performed. In this step, as in the first embodiment, the lead
terminals 224 and the second terminal portions 282b are directly
joined to each other by sandwiching the lead terminals 224 and the
second terminal portions 282b between a pair of welding electrodes.
Thereafter, a thermosetting resin is injected into the internal
space 204a to form the potting portion 242.
[0539] In the configuration group E, according to the present
embodiment, in the internal space 204a of the housing 201, the
connector terminals 208a do not enter between the housing opening
241 and the sensor SA 220 in the width direction X. For that
reason, after the connector terminals 208a have been attached to
the housing 201, the sensor SA 220 can be inserted into the
internal space 204a from the housing opening 241. This eliminates
the need for attaching the connector terminals 208a to the housing
201 after the sensor SA 220 has been installed in the internal
space 204a. For that reason, the sensor SA 220 can be inhibited
from being positionally deviated due to an impact or the like
caused by the attachment of the connector terminals 208a to the
housing 201.
[0540] According to the present embodiment, in the internal space
204a, the second terminal portions 282b of the connector terminals
208a are accommodated in the flow channel region QA and the support
region QB in a state where the second terminal portions 282b do not
protrude into the connector region QC. For that reason, a
configuration can be realized in which the second terminal portions
282b are not inserted between the housing opening 241 and the
sensor SA 220 in the width direction X. When inserting the sensor
SA 220 into the internal space 204a from the housing opening 241,
the operator simply prevents the SA main body 225 from entering the
connector region QC, thereby being capable of preventing the SA
main body 225 from coming in contact with the second terminal
portions 282b. This makes it possible to inhibit the SA main body
225 and the connector terminals 208a from being damaged or deformed
when the SA main body 225 and the connector terminals 208a are
contacted with each other due to the attachment of the sensor SA
220 to the housing 201.
[0541] According to the present embodiment, in the internal space
204a, the lead terminals 224 of the sensor SA 220 are disposed at
positions that extend across the boundary between the support
region QB and the connector region QC. In this case, the lead
terminals 224 can be connected directly to the connector terminals
208a. For that reason, the number of welding operations performed
in the internal space 204a for electrically connecting the lead
terminals 224 and the connector terminals 208a can be minimized.
For that reason, the positional deviation of the sensor SA 220 can
be inhibited from occurring due to the weld operation in the
internal space 204a.
[0542] According to the present embodiment, the connector terminals
208a are temporarily attached to the mold device used for resin
molding of the base member 261, so that the base member 261 can be
molded in a state in which at least a part of the connector
terminals 208a is embedded. For that reason, the positional
deviation of the connector terminal 208a with respect to the base
member 261 can be inhibited from occurring.
[0543] According to the present embodiment, the sensor SA 220 and
the connector terminals 208a are covered with the thermosetting
resin injected into the internal space 204a from the housing
opening 241. For that reason, the positional deviation of the
sensor SA 220 and the deformation or breakage of the lead terminals
224 and the connector terminals 208a can be inhibited by the
potting portion 242 made of the thermosetting resin.
[0544] <Description of Configuration Group F>
[0545] A configuration group F relating to covering the detection
unit will be described with reference to FIG. 72 and the like.
[0546] As shown in FIG. 61, the housing opening 241 is disposed
between the sealing holder 205 and the inflow port 213a in the
height direction Y. In this example, if the housing attachment is
configured to include the sealing holder 205 and the flange portion
207, the housing opening 241 is disposed between the housing
attachment and the inflow port 213a. As described above, in FIG.
72, the lead terminals 224 of the sensor SA 220 and the connector
terminals 208a are connected to each other, and a connection
portion 291 is accommodated in the connector region QC. The support
region QB and the connector region QC configure a sealing region,
and the potting portion 242 corresponds to a filling portion. A
thermosetting resin which is filled in the internal space 204a and
then cured to form the potting portion 242 corresponds to a
filler.
[0547] In the configuration group F, according to the present
embodiment, since the potting portion 242 is formed by injecting
the thermosetting resin into the internal space 204a, when the
internal space 204a is sealed, a pressure is hardly applied to the
internal space 204a. In this case, since the positional deviation
of the sensor SA 220 is inhibited from being unintentionally caused
by the pressure applied to the internal space 204a, the positional
deviation of the sensor SA 220 hardly varies from product to
product. Therefore, the detection accuracy of the flow rate
detector 202 can be inhibited from varying from product to
product.
[0548] According to the present embodiment, in the internal space
204a, in addition to the sensor SA 220, the connection portion 291
between the lead terminals 224 and the connector terminals 208a is
covered with the potting portion 242. For that reason, not only the
sensor SA 220 but also the connection portion 291 can be protected
by a sealing performance of the potting portion 242.
[0549] According to the present embodiment, the housing opening 241
is disposed between the sealing holder 205 and the inflow port 213a
in the height direction Y. For that reason, a configuration can be
realized in which the housing opening 241 is disposed in the intake
passage 12 which is not outside the intake pipe 12a but inside the
intake pipe 12a. In this case, since a heat is hardly directly
applied to the potting portion 242 from a heat source such as the
internal combustion engine 11, the deterioration of the potting
portion 242 due to heat can be reduced. As a result, the sealing
performance of the internal space 204a by the potting portion 242
can be exhibited for a long period of time.
[0550] <Description of Configuration Group G>
[0551] A configuration group G relating to the information portion
will be described with reference to FIG. 73 and the like.
[0552] As shown in FIG. 73, in the housing 201, when an outer
surface of the front wall portion 233 is referred to as a housing
front face 301 and an outer surface of the back wall portion 234 is
referred to as a housing back face, the housing opening 241 is
provided in the housing 201. A plurality of thinned portions 302
recessed toward the back wall portion 234 are provided on the
housing front face 301. The thinned portions 302 are provided on
the cover member 262 forming the housing front face 301. The
housing front face 301 corresponds to a housing front face which is
one surface of the housing.
[0553] The housing opening 241 is an open end portion of the
internal space 204a, and as described above, the internal space
204a is sealed from the housing opening 241 side by the potting
portion 242. In the potting portion 242, the potting surface 303,
which is an outer surface thereof, faces away from the sensor SA 50
in the width direction X, as with the housing front face 301.
Further, the potting material filled in the internal space 204a
creeps up the inner peripheral surfaces of the support region QB
and the connector region QC, so that the peripheral portion of the
potting surface 303 is easily curved. However, as a whole of the
potting surface 303, most portions except for the peripheral
portion are flat surfaces. In this case, the potting portion 242
corresponds to a sealing portion, and the potting surface 303
corresponds to an outer surface of the sealing portion.
[0554] In the housing 201, the housing opening 241 is disposed
between the sealing holder 205 and the inflow port 213a in the
height direction Y. In this case, in a state in which the air flow
meter 200 is attached to the intake pipe 12a, both the inflow port
213a and the potting portion 242 are disposed in the intake passage
12 inside the intake pipe 12a.
[0555] The housing opening 241 is formed in a rectangular shape as
a whole. In this case, the housing opening 241 has a pair of first
side portions 305, which are long sides, and a pair of second side
portions 306, which are short sides, and has a flat shape extending
in the height direction Y as a whole. In this case, the first side
portions 305 extend in the height direction Y, and the second side
portions 306 extend in the depth direction Z. In the present
embodiment, the four corners of the housing opening 241 are not
chamfered, and the first side portions 305 and the second side
portions 306 are directly connected to each other. The first side
portions 305 correspond to opposite sides.
[0556] The potting surface 303 is provided with an information
portion 304 similar to the information portion 194 in the first
embodiment. In the information portion 304, a number string and a
character string are aligned along the first side portions 305.
[0557] In the configuration group G, according to the present
embodiment, since the potting portion 242 is formed by injecting
the potting material into the internal space 204a, most of the
potting surface 303 can be flattened. In addition, since the
housing opening 241 and the internal space 204a are large enough to
allow the sensor SA 220 to be inserted from the plate surface of
the SA main body 225, the housing opening 241 and the internal
space 204a are unlikely to cause a shortage of the potting surface
303 in displaying the information portion 304. As described above,
since the potting surface 303 is planarized and enlarged, the
visibility of the information portion 304 imparted to the potting
surface 303 can be enhanced.
[0558] According to the present embodiment, in the internal space
204a of the housing 201, the SA main body 225 of the sensor SA 220
and the connector terminals 208a are aligned side by side in the
height direction Y. For that reason, the width dimension of the
internal space 204a and the width dimension of the housing opening
241 are increased in the height direction Y to such an extent that
the SA main body 225 and the connector terminals 208a can be
disposed laterally. In other words, the width dimension of the
potting surface 303 increases in the height direction Y. In this
case, since the size of the information portion 304 can be enlarged
on the potting surface 303, the visibility of the information
portion 304 can be enhanced.
[0559] According to the present embodiment, since the housing
opening 241 is flattened as a whole so that the pair of first side
portions 305 are long sides, an alignment direction of the
information portions 304 can be clarified. In this case, since the
number string and the character string of the information portion
304 are aligned along the first side portions 305 on the potting
surface 303, the operator can be inhibited from reading the number
string and the character string incorrectly. In this manner, the
visibility of the information portion 304 can be enhanced by the
shape of the potting surface 303.
[0560] According to the present embodiment, the housing front face
301 is provided with thinned portions 302. In this example, if an
attempt is made to secure a flat surface on the housing front face
301 that is large enough to prevent the visibility of the
information portion 304 from being insufficient, there is a fear
that the thinned portions 302 on the housing front face 301 will be
insufficient. If the housing front face 301 is short of the thinned
portions 302, the cover member 262 becomes thick, which may cause
unintentional deformation of the cover member 262 due to curing of
the molten resin when molding the cover member 262. On the other
hand, in the present embodiment, since the information portion 304
is provided on the potting surface 303, there is no need to secure
a flat surface suitable for display of the information portion 304
on the housing front face 301. In this case, when a sufficient
amount of the thinned portions 302 are disposed on the housing
front face 301, the deformation of the cover member 262 due to
resin molding can be reduced, and the visibility of the information
portion 304 on the potting surface 303 can be enhanced.
[0561] According to the present embodiment, in the internal space
204a of the housing 201, the sensor SA 220 is covered with the
potting portion 242. In this example, unlike the present
embodiment, for example, in a configuration in which a lid member
molded of resin as a member different from the housing 201 is
attached to the housing opening 241, as the housing opening 241 is
larger, the lid member becomes larger. When the lid member is
increased in size, there is a need to form the thinned portions 302
on the lid member as well as on the cover member 262, which makes
it difficult to secure a flat surface to the extent that the
information portion 304 can be provided by the lid member.
[0562] On the other hand, according to the present embodiment, the
potting portion 242 to which the information portion 304 is added
does not need to form the thinned portions 302 because the resin
molding is not performed. Moreover, in the potting portion 242
filled in the internal space 204a, the phenomenon that the potting
surface 303 is inevitably flattened is leveraged, thereby being
capable of disposing the information portion 304 almost entirely on
the potting surface 303. Therefore, the visibility of the
information portion 304 can be enhanced on the potting surface
303.
Fifth Embodiment
[0563] In the first embodiment, a part of the flow channel boundary
portion 34 and a part of the outflow port 33b overlap with each
other, but in a fifth embodiment, a flow channel boundary portion
34 and an outflow port 33b are separated from each other in the
depth direction Z. The present embodiment will be described with
reference to FIGS. 74 to 79 focusing on differences from the first
embodiment.
[0564] <Description of Configuration Group D>
[0565] A configuration group D relating to the configuration of the
passage flow channel will be described. As shown in FIGS. 74 and
75, a passage flow channel 31 has a shape extending downstream of
the flow channel boundary portion 34 in the depth direction Z. In
this case, in addition to an inflow passage 31a and an outflow
passage 31b, the passage flow channel 31 has a connection passage
331 that connects the inflow passage 31a and the outflow passage
31b. The connection passage 331 is provided between the inflow
passage 31a and the outflow passage 31b, and extends from the flow
channel boundary portion 34 toward a passage floor surface 152. In
this case, the outflow passage 31b is located between the flow
channel boundary portion 34 and the outflow port 33b in the depth
direction Z.
[0566] In the passage flow channel 31, the whole of the passage
floor surface 152 is a floor throttle surface 152a. In this case,
the floor throttle surface 152a is in a state of extending over the
inflow port 33a and the outflow port 33b. The floor throttle
surface 152a corresponds to a floor inclined surface. The wall
throttle surface 153a is provided between the flow channel boundary
portion 34 and the outflow port 33b in the depth direction Z, and
is disposed in the entire outflow passage 31b in the depth
direction Z. In this case, the wall throttle surface 153a extends
over the connection passage 331 and the outflow port 33b.
[0567] A passage ceiling surface 151 has an inflow ceiling portion
332a provided on the inflow port 33a side of the flow channel
boundary portion 34, and an outflow ceiling portion 332b provided
on the outflow port 33b side of the flow channel boundary portion
34. The inflow ceiling portion 332a extends across the inflow port
33a and the flow channel boundary portion 34, and extends in the
depth direction Z which is a direction in which the inflow port 33a
and the outflow port 33b are aligned. The outflow ceiling portion
332b extends over the flow channel boundary portion 34 and the
outflow port 33b, and is inclined with respect to the inflow
ceiling portion 332a by being directed toward the inflow port 33a
side.
[0568] The flow channel boundary portion 34 is inclined with
respect to the inflow ceiling portion 332a by being directed toward
the outflow port 33b side in the same manner as that in the first
embodiment. The floor throttle surface 152a is also inclined with
respect to the inflow ceiling portion 332a. An inclination angle 83
of the floor throttle surface 152a with respect to the inflow
ceiling portion 332a is equal to or larger than an inclination
angle 82 of the flow channel boundary portion 34 with respect to
the inflow ceiling portion 332a. As described above, the flow
channel boundary portion 34 corresponds to a branch boundary. In
addition, similarly to the first embodiment, even if a person looks
into the passage flow channel 31 from the inflow port 33a in the
depth direction Z, the flow channel boundary portion 34 is hidden
on the back side of a ceiling surface of the inflow passage 31a and
is not visible. In this case, even if foreign matter such as dust,
dust, waterdrops, and oil droplets fly along with an intake air,
the foreign matter easily travels straight along the passage flow
channel 31 and is discharged from the outflow port 33b. For that
reason, the foreign matter does not reach the flow rate detector
22, thereby being capable of preventing the detection element 22b
from being damaged due to the foreign matter, and the detection
accuracy of the flow rate detector 22 from being deteriorated due
to the accumulation of the foreign matter.
[0569] Next, the mold device 90 will be described with reference to
FIGS. 76 and 77.
[0570] As shown in FIGS. 76 and 77, an introduction molding portion
97b of a measurement molding portion 97 does not reach the outflow
port 33b, and does not abut against outer peripheral mold portions
102 and 103. For that reason, unlike the first embodiment, the
introduction molding portion 97b does not have an outer measurement
surface 161 that abuts against the outer peripheral mold portions
102 and 103. An inner measurement surface 162 of the measurement
molding portion 97 and an inner passage surface 159 of the passage
mold portion 104 abut against each other as in the first
embodiment, and are further caught by each other.
[0571] The measurement molding portion 97 has a mold projection
portion 334 in which the inner measurement surface 162 protrudes
toward the inner passage surface 159, and the passage mold portion
104 has a mold recess portion 335 in which the inner passage
surface 159 is recessed toward the opposite side of the inner
measurement surface 162. In both the width direction X and the
depth direction Z, the mold projection portion 334 is disposed at
an intermediate position of the inner measurement surface 162, and
the mold recess portion 335 is disposed at an intermediate position
of the inner passage surface 159. In that case, since the mold
projection portion 334 is fitted into the mold recess portion 335,
so that the four sides of the mold projection portion 334 are
surrounded by an inner peripheral surface of the mold recess
portion 335. For that reason, the mold projection portion 334 is
caught on the inner peripheral surface of the mold recess portion
335 to restrict the movement of the measurement molding portion 97
and the passage mold portion 104 relative to each other in the
width direction X and the depth direction Z.
[0572] The inner measurement surface 162 of the measurement molding
portion 97 and the inner passage surface 159 of the passage mold
portion 104 are in contact with each other at the flow channel
boundary portion 34. On the other hand, the mold projection portion
334 passes the flow channel boundary portion 34 and enters the
passage flow channel 31, and the mold projection portion 334 and
the mold recess portion 335 are fitted to each other in the passage
flow channel 31. In this case, the passage mold portion 104 does
not have a portion that has entered the measurement flow channel 32
side beyond the flow channel boundary portion 34.
[0573] Next, a description will be given of a procedure for
removing the mold device 90 from the housing 21 molded with resin
in the method of manufacturing the air flow meter 14.
[0574] As shown in FIG. 78, the measurement molding portion 97 is
extracted from the measurement flow channel 32 of the housing 21
prior to the passage mold portion 104. This is because the passage
mold portion 104 cannot be moved in the depth direction Z with
respect to the measurement molding portion 97 because the mold
projection portion 334 is in a state of entering the mold recess
portion 335. As shown in FIG. 79, after the measurement molding
portion 97 has been extracted from the housing 21, the passage mold
portion 104 is extracted from the inflow port 33a of the housing
21.
[0575] When the passage mold portion 104 is extracted from the
inflow port 33a, the passage mold portion 104 is moved to the
inflow port 33a side along the floor throttle surface 152a of the
passage flow channel 31. For example, when the passage mold portion
104 is moved to the inflow port 33a side along the inflow ceiling
portion 332a of the passage flow channel 31, the inner passage
surface 159 is caught by an upstream end portion of the inflow
ceiling portion 332a and cannot be extracted from the inflow port
33a. This is because at least a part of the inner passage surface
159 of the passage mold portion 104 is disposed closer to a housing
base end side than the inflow port 33a in the height direction
Y.
[0576] In addition, unlike the present embodiment, in the
configuration in which the inclination angle 83 of the floor
throttle surface 152a is smaller than the inclination angle 82 of
the flow channel boundary portion 34, the passage mold portion 104
is shaped to be thickened toward the outer passage surface 158. For
that reason, even if the passage mold portion 104 is moved toward
the inflow port 33a side along the floor throttle surface 152a of
the passage flow channel 31, the passage mold portion 104 cannot be
extracted from the inflow port 33a. In this case, in the passage
mold portion 104, a separation distance between the floor throttle
molding surface 156 and the inner passage surface 159 gradually
increases toward the outer passage surface 158.
[0577] Further, unlike the present embodiment, even if the outflow
ceiling portion 332b of the passage flow channel 31 does not face
the inflow port 33a side, but faces the outflow port 33b side, the
passage mold portion 104 becomes thicker toward the outer passage
surface 158. For that reason, the passage mold portion 104 cannot
be extracted from the inflow port 33a.
[0578] In the configuration group D, according to the present
embodiment, since the mold projection portion 334 enters the mold
recess portion 335 in the mold device 90, a relative positional
deviation between the measurement molding portion 97 and the
passage mold portion 104 can be regulated. Moreover, since the four
sides of the mold projection portion 334 are surrounded by the
inner peripheral surface of the mold recess portion 335, the
relative positional deviation between the measurement molding
portion 97 and the passage mold portion 104 can be regulated in
both the width direction X and the depth direction Z. For that
reason, the measurement molding portion 97 and the passage mold
portion 104 are displaced from each other and a step is formed at
the boundary between the mold portions 97 and 104, as a result of
which a step can be inhibited from occurring on the inner
peripheral surfaces of the passage flow channel 31 and the
measurement flow channel 32. This makes it possible to inhibit that
the air flow is disturbed by the step formed on the inner
peripheral surface of the passage flow channel 31 or the
measurement flow channel 32, and the detection accuracy of the flow
rate detector 22 is lowered.
[0579] According to the present embodiment, the inclination angle
83 of the floor throttle surface 152a is equal to or larger than
the inclination angle 82 of the flow channel boundary portion 34
with reference to the depth direction Z. For that reason, in order
to inhibit the entry of the foreign matter into the measurement
flow channel 32, even if the flow channel boundary portion 34 is
inclined with respect to the depth direction Z so as to face the
side of the outflow port 33b, a configuration can be realized in
which the passage mold portion 104 can be extracted from the inflow
port 33a.
Sixth Embodiment
[0580] In a sixth embodiment, a lead terminal 54 of a sensor SA 50
is connected to a connector terminal 28a through no bridge terminal
86. The present embodiment will be described with reference to
FIGS. 80 and 81 focusing on differences from the first
embodiment.
[0581] <Description of Configuration Group E>
[0582] A configuration group E relating to the position of the
connector terminal will be described. As shown in FIG. 80, the lead
terminal 54 of the sensor SA 50 does not extend straight toward a
housing opening 61 in the height direction Y, but is bent so as to
extend toward the connector terminal 28a.
[0583] The lead terminal 54 has a first lead portion 341 extending
from an SA main body 170, a second lead portion 342 extending along
a second terminal portion 172b of the connector terminal 28a, and a
third lead portion 343 connecting the lead portions 341 and 342.
The first lead portion 341 extends from the SA main body 170 toward
a housing opening 61. The second lead portion 342 is disposed
closer to the connector terminal 28a than the first lead portion
341, and extends from the third lead portion 343 toward the housing
opening 61. The first lead portion 341 and the second lead portion
342 extend in the height direction Y in parallel with each other.
The third lead portion 343 extends from the first lead portion 341
toward the connector terminal 28a in the width direction X. The
first lead portion 341 corresponds to a detection lead portion. The
second lead portion 342 and the third lead portion 343 configure a
connection lead portion connected to the first lead portion
341.
[0584] The lead terminal 54 extends across a boundary between a
main body region PC1 and a connector region PC2 in the width
directions X. In the lead terminal 54, the first lead portion 341
is disposed in the main body region PC1, the second lead portion
342 is disposed in the connector region PC2, and the third lead
portion 343 is disposed at a position extending across the boundary
between the main body region PC1 and the connector region PC2 in
the width directions X. The lead terminal 54 corresponds to a
detection terminal.
[0585] The second lead portion 342 enters between a sealing step
surface 67 and a housing opening 61 in the height direction Y, and
at least one of the second lead portion 342 and the third lead
portion 343 comes in contact with the sealing step surface 67. In
this case, the sealing step surface 67 supports a connection
portion between the second lead portion 342 and the second terminal
portion 172b.
[0586] Next, a method of manufacturing an air flow meter 14 will be
described with reference to FIGS. 80 and 81, focusing on the fact
that the lead terminals 54 and the connector terminal 28a are
directly connected to each other.
[0587] First, a procedure of manufacturing the sensor SA 50 will be
described. In this example, the sensor SA having high versatility
is referred to as a general purpose SA, and the general purpose SA
has the SA main body 170 and the first lead portion 341, but does
not have the second lead portion 342 and the third lead portion
343. In the present embodiment, the sensor SA 50 is manufactured by
connecting the second lead portion 342 and the third lead portion
343 to the first lead portion 341 of the general purpose SA by
welding or the like.
[0588] The sensor SA 50 is not manufactured by attaching the lead
portions 342 and 343 to the general purpose SA, but may be
manufactured by attaching the lead terminal 54 having the first
lead portion 341, the second lead portion 342, and the third lead
portion 343 to the SA main body 170. The first lead portion 341 of
the general purpose SA is a portion corresponding to the lead
terminals 54 of the sensor SA 50 of the first embodiment, and the
sensor SA 50 of the first embodiment can also be referred to as a
general purpose SA having high versatility.
[0589] After a housing 21 has been molded with resin, as shown in
FIG. 81, the sensor SA 50 is inserted into an internal space 24a of
the housing 21. In this example, similarly to the first embodiment,
the sensor SA 50 inserted from the housing opening 61 is pushed
into the internal space 24a until a circuit step surface 55 is
caught by a region step surface 66. In this example, it is assumed
that the second lead portion 342 and the third lead portion 343 of
the lead terminal 54 are caught by the sealing step surface 67
before the SA main body 170 is caught by the region step surface
66. Even in this instance, the lead terminal 54 caught by the
sealing step surface 67 is deformed as a whole, so that the sensor
SA 50 can be pushed into the internal space 24a further deeply. For
that reason, even if the lead terminal 54 is disposed at a position
extending across a boundary between the main body region PC1 and
the connector region PC2, the positional deviation of the sensor SA
50 is inhibited from occurring by the lead terminal 54 being caught
by the sealing step surface 67.
[0590] After the sensor SA 50 has been installed in the internal
space 24a, a step of connecting the lead terminal 54 and the
connector terminal 28a with the use of a joining tool is performed.
In this step, a pair of welding electrodes are inserted into the
internal space 24a from the housing opening 61, the second bridge
portion 173b and the second terminal portion 172b are sandwiched by
those welding electrodes, and welding between the second bridge
portion 173b and the second terminal portion 172b is performed. As
described above, in the present embodiment, the lead terminal 54
and the connector terminal 28a are joined directly to each other,
so that the number of joining portions requiring a joining
operation after the sensor SA 50 has been installed in the internal
space 24a is reduced as much as possible.
[0591] For example, in the configuration of indirectly connecting
the lead terminal 54 and the connector terminal 28a as in the first
embodiment, the welding operation for the lead terminal 54 and the
welding operation for the connector terminal 28a are performed
separately. Compared to the above configuration, in the present
embodiment, since the lead terminal 54 and the connector terminal
28a are directly joined to each other, the number of joining
portions requiring a joining operation after the sensor SA 50 has
been installed in the internal space 24a is reduced to half.
[0592] In the configuration group E, according to the present
embodiment, even if the lead terminal 54 does not extend straight
toward the housing opening 61, if the lead terminal 54 extends
generally toward the housing opening 61, the second lead portion
342 is disposed in the connector region PC2. In other words, the
second lead portion 342 is disposed at a position closer to the
housing opening 61 than the SA main body 170. In this case, since
there is no need to insert a joining tool for joining the second
lead portion 342 and the second terminal portion 172b deeply into
the internal space 24a, a work load when joining can be
reduced.
[0593] According to the present embodiment, in the internal space
24a of the housing 21, the lead terminal 54 of the sensor SA 50 is
disposed at a position that extends across the boundary between the
main body region PC1 and the connector region PC2. In this case,
since the lead terminal 54 can be directly connected to the
connector terminal 28a, the number of welding operations performed
in the internal space 24a for electrically connecting the lead
terminal 54 and the connector terminal 28a can be minimized. For
that reason, the positional deviation of the sensor SA 50 can be
inhibited from occurring due to the welding operation in the
internal space 24a.
[0594] According to the present embodiment, since the second
terminal portion 172b of the connector terminals 28a is supported
by the sealing step surface 67, unintentional displacement of the
second terminal portion 172b can be inhibited when the second
terminal portion 172b and the second lead portion 342 are joined to
each other. This makes it possible to inhibit that the second
terminal portion 172b is relatively displaced with respect to the
second lead portion 342 during the joining operation, which makes
it difficult to properly join the second terminal portion 172b and
the second lead portion 342.
[0595] According to the present embodiment, in the lead terminal
54, the second lead portion 342 inserted between the sealing step
surface 67 and the housing opening 61 is supported by the sealing
step surface 67 from the side opposite to the housing opening 61.
In this example, in the sensor SA 50, the second lead portion 342
is easily displaced because the first lead portion 341 cantilevers
the second lead portion 342 and the third lead portion 343. In this
case, when the second lead portion 342 is joined to the second
terminal portion 172b, the second lead portion 342 is relatively
displaced with respect to the second terminal portion 172b, which
may increase the difficulty of the joining operation or may prevent
proper joining. On the contrary, according to the present
embodiment, since the second lead portion 342 is supported by the
sealing step surface 67, a state in which the first lead portion
341 cantilevers the second lead portion 342 and the third lead
portion 343 is eliminated. For that reason, the joining operation
between the second lead portion 342 and the second terminal portion
172b can be facilitated.
[0596] According to the present embodiment, the sealing step
surface 67 supporting the second lead portion 342 of the sensor SA
50 is disposed at a position closer to the housing opening 61 than
the region step surface 66. In this case, when the second lead
portion 342 and the second terminal portion 172b are joined to each
other, there is no need to insert the joining tool to a position
deeper than the sealing step surface 67 in the internal space 24a,
so that the joining tool can be inhibited from unintentionally
coming into contact with the SA main body 170.
[0597] According to the present embodiment, the second terminal
portion 172b and the second lead portion 342 extend from the
sealing step surface 67 toward the housing opening 61. In this
case, when the second terminal portion 172b and the second lead
portion 342 are sandwiched between a joining tool such as welding
electrodes, there is no need to insert the joining tool into a back
side of the second terminal portion 172b and the second lead
portion 342 when viewed from the housing opening 61. For that
reason, when the second terminal portion 172b and the second lead
portion 342 are joined to each other with the use of the joining
tool, the joining operation can be facilitated.
[0598] According to the present embodiment, in the sensor SA 50,
the lead terminal 54 is formed by connecting the second lead
portion 342 and the third lead portion 343 to the first lead
portion 341 extending from the SA main body 170. In this instance,
the sensor SA 50 can be manufactured with the use of a general
purpose SA that does not have the second lead portion 342 and the
third lead portion 343. For that reason, after the connector
terminal 28a has been fixed to the housing 21, the sensor SA 50 can
be installed in the internal space 24a of the housing 21, and the
costs for manufacturing the sensor SA 50 can be reduced.
Other Embodiments
[0599] Although a plurality of embodiments according to the present
disclosure have been described above, the present disclosure is not
construed as being limited to the above-mentioned embodiments, and
can be applied to various embodiments and combinations within a
scope not departing from the spirit of the present disclosure.
[0600] <Modification of Configuration Group A>
[0601] In Modification 1, the housing 21 does not need to have the
passage flow channel 31. In other words, the bypass flow channel 30
may have only the measurement flow channel 32. For example, the
longitudinal partition wall 69 extends to the housing bottom
portion 62. In the above configuration, all of the intake air
flowing in from the inflow port 33a is guided to the introduction
path 32b of the measurement flow channel 32 and discharged from the
measurement outlet 33c. In the above configuration, in order to
prevent the outflow port 33b from being molded during resin molding
of the housing 21, the tip portion of the passage mold portion 104
does not abut against the outer peripheral mold portions 102 and
103 in the mold device 90.
[0602] As Modification 2, in the measurement flow channel 32, the
flow rate detector 22 may be provided in the introduction path 32b
and the discharge path 32c. In this case, the detection path 32a
serves as a connection path connecting the introduction path 32b
and the discharge path 32c. For example, as a configuration in
which the flow rate detector 22 is provided in the introduction
path 32b, there is a configuration in which the sensing support
portion 57 extends toward the housing tip side to the extent that
the sensing support portion 57 reaches the introduction path 32b in
the sensor SA 50. In this configuration, since the flow rate
detector 22 is provided at a position close to the tip portion of
the sensing support portion 57, the flow rate detector 22 can be
disposed in the introduction path 32b.
[0603] As Modification 3, in the measurement flow channel 32, the
introduction path 32b and the discharge path 32c may be aligned not
in the depth direction Z but in the width direction X. In this
configuration, the detection path 32a extends in the width
direction X, but the flow rate detection by the flow rate detector
22 can be appropriately performed only with the flow direction of
the intake air in the detection path 32a being not the depth
direction Z.
[0604] In Modification 4, the boundary between the sealing region
PA and the open region PB may coincide with the sensing step
surface 56 instead of the circuit step surface 55 of the sensor SA
50. For example, the region step surface 66 of the housing 21
disposed at a position of abutting against the sensing step surface
56 of the sensor SA 50, and the sealing region PA and the
accommodation region PB1 are sealed by the potting portion 65. In
the above configuration, a gap is not defined between the outer
peripheral surface of the junction portion 52 of the sensor SA 50
and the inner peripheral surface of the housing body 24 on the
accommodation region PB1.
[0605] As Modification 5, the detection throttle portions 59 may be
provided on both sides of the sensing support portion 57 in the
width direction X. In this case, the housing 21 has a pair of
detection throttle portions 59 aligned in the width direction X,
and the sensing support portion 57 and the flow rate detector 22
are disposed between the detection throttle portions 59. Even in
the above configuration, it is preferable that the pair of
detection throttle portions 59 and the longitudinal partition wall
69 do not become thick even toward the housing opening 61 as a
whole. As a result, the inner peripheral surface of the housing 21
can be integrally molded.
[0606] As Modification 6, in the mold device 90, the first outer
peripheral mold portion 102 and the second outer peripheral mold
portion 103 may be aligned in the depth direction Z instead of the
width direction X. The number of mold portions for molding the
outer peripheral surface of the housing 21 may be three or more
instead of two as in the case of the outer peripheral mold portions
102 and 103. Further, if the housing 21 can be removed from the
outer peripheral surface, one mold portion for molding the outer
peripheral surface of the housing 21 may be used.
[0607] As Modification 7, when the housing 21 is molded with resin,
a plurality of mold portions may be taken out from the housing
opening 61, as well as one mold portion like the inner peripheral
mold portion 91. For example, the first inner peripheral mold
portion having the introduction molding portion 97b and the second
inner peripheral mold portion having the discharge molding portion
97c are formed independently of each other, and in the mold device
90, those inner peripheral mold portions are combined with each
other and inserted into the outer peripheral mold portions 102 and
103. Also, in the above configuration, it is preferable that the
first inner peripheral mold portion and the second inner peripheral
mold portion can be pulled out from the housing opening 61
collectively or sequentially.
[0608] As Modification 8, the outlet extension portion 113 for
molding the measurement outlet 33c may be included in a dedicated
mold portion independent of the outer peripheral mold portions 102
and 103, instead of being included in the outer peripheral mold
portions 102 and 103. For example, a dedicated mold portion
including the outlet extension portion 113 is provided between the
first outer peripheral mold portion 102 and the second outer
peripheral mold portion 103 in the mold device 90 in the same
manner as the passage mold portion 104. With the use of the
dedicated mold portion in this manner, the opening direction of the
measurement outlet 33c can be easily changed not to the width
direction X but to the depth direction Z.
[0609] In Modification 9, the measurement outlet 33c may be
provided not in the discharge path 32c but in the detection path
32a. For example, the measurement outlet 33c is provided on the
downstream side of the flow rate detector 22 in the detection path
32a. In the above configuration, the intake air that has passed
through the flow rate detector 22 is discharged to the outside from
the measurement outlet 33c without passing through the discharge
path 32c. In this case, the discharge path 32c may not be provided.
Even in a configuration in which the discharge path 32c is not
provided, if the introduction path 32b is not narrowed even when
the introduction path 32b approaches the housing opening 61 in the
height direction Y, the inward portion 93 of the inner peripheral
mold portion 91 can be extracted from the housing opening 61 at the
time of resin molding of the housing 21. In the above
configuration, the inward portion 93 does not have the discharge
molding portion 97c.
[0610] As Modification 10, the configuration functioning as the
control device of the combustion system is not the ECU 20, but may
be a variety of calculation devices mounted in a vehicle, and
multiple calculation devices may function as the control device in
cooperation with each other. In addition, various programs may be
stored in a non-transitory tangible storage medium such as a flash
memory or a hard disk provided in each calculation device.
[0611] <Modifications of Configuration Group B>
[0612] As Modification B1, in the first embodiment, the measurement
outlet 33c may be provided on one of the front surface and the back
surface of the housing 21, instead of the measurement outlet 33c
provided on each of the front surface and the back surface. For
example, as shown in FIGS. 82 and 83, the measurement outlet 33c is
provided on the surface of the housing 21. In the above
configuration, the housing 21 has an asymmetric shape on the front
side and the back side, and the outflow port 33b is also provided
on the surface of the housing 21, not on the outer peripheral
downstream end 132b but on the surface of the housing 21 as with
the measurement outlet 33c. The outflow port 33b and the
measurement outlet 33c are not formed in a rectangular shape but
formed in a circular shape.
[0613] In addition to the flat surface 44 and the curved surface
45, the surface of the housing 21 has a downstream tapered surface
401 that extends straight in a state inclined with respect to the
depth direction Z from the outer peripheral downstream end 132b
toward the upstream side. On the surface of the housing 21, since
the flat surface 44 and the curved surface 45 are aligned
horizontally in the depth direction Z, a vertical boundary 131a
linearly extends from the flange portion 27 to the tip of the
housing 21 in the height direction Y, and the vertical boundary
131a is not formed. In addition, the flat surface 44 and the
downstream tapered surface 401 are aligned horizontally in the
depth direction Z, and a tapered boundary 402, which is a boundary
between the flat surface 44 and the downstream tapered surface 401,
extends in parallel with the vertical boundary 131a. A back surface
of the housing 21 does not have the downstream tapered surface 401,
and the flat surface 44 extends in the depth direction Z from the
outer peripheral downstream end 132b toward the curved surface
45.
[0614] On the surface of the housing 21, similarly to the first
embodiment, the measurement outlet 33c is disposed at a position
extending across the vertical boundary 131a in the depth direction
Z. The outflow port 33b is provided on the flat surface 44 between
the vertical boundary 131a and the tapered boundary 402, instead of
the outer peripheral downstream end 132b. The outflow port 33b may
be provided on the curved surface 45 or the downstream tapered
surface 401, or may be provided at a position extending across the
vertical boundary 131a in the depth direction Z similarly to the
measurement outlet 33c.
[0615] As Modification B2, in the first embodiment, the curved
surface 45 of the housing 21 may be an outer peripheral inclined
surface inclined with respect to the depth direction Z. For
example, as shown in FIG. 85, the outer peripheral inclined surface
may be a tapered surface extending straight from the flat surface
44 toward the outer peripheral upstream end 132a. The outer
peripheral inclined surface may be a surface curved so as to be
recessed toward the inner peripheral side of the housing 21. In
either case, since the measurement outlet 33c is disposed at a
position extending across the vertical boundary 131a as the outer
peripheral boundary, a configuration can be realized in which the
measurement outlet 33c is not opened toward the downstream
side.
[0616] As Modification B3, the measurement outlet may be provided
only on the outer peripheral inclined surface out of the outer
peripheral flat surface and the outer peripheral inclined surface.
For example, in the first embodiment, as shown in FIG. 84, the
measurement outlet 33c is provided on the curved surface 45 so as
not to protrude from the flat surface 44. In the above
configuration, the measurement outlet 33c does not extends across
the vertical boundary 131a in the depth direction Z, but extends
from the vertical boundary 131a toward the outer peripheral
upstream end 132a in the depth direction Z, and the outlet
downstream end 134b of the measurement outlet 33c is included in
the vertical boundary 131a.
[0617] Further, as shown in FIG. 85, the measurement outlet 33c is
provided on an upstream tapered surface 404 as the outer peripheral
inclined surface so as not to protrude to the flat surface 44. In
the above configuration, an upstream tapered surface 404 is
included in the outer peripheral surface of the housing 21 instead
of the curved surface 45, and the boundary between the upstream
tapered surface 404 and the flat surface 44 is the vertical
boundary 131a. The upstream tapered surface 404 extends straight
from the vertical boundary 131a toward the outer peripheral
upstream end 132a, and is inclined with respect to the depth
direction Z. Also, in the above configuration, the outlet
downstream end 134b of the measurement outlet 33c is included in
the vertical boundary 131a.
[0618] In either of the configurations of FIGS. 84 and 85, the
measurement outlet 33c is disposed on the outer peripheral inclined
surface and is not opened to the downstream side. For that reason,
even if the turbulence of the air flow occurs around the outer
peripheral downstream end 132b in the intake passage 12, the flat
surface 44 can inhibit the turbulence from reaching the measurement
outlet 33c. Further, as in the first embodiment, a forward flow air
such as the air AF1 flows along the outer peripheral inclined
surface before reaching the measurement outlet 33c, so that a
traveling direction changes to a direction substantially
perpendicular to the opening direction of the measurement outlet
33c, and therefore, the forward flow air hardly flows into the
measurement outlet 33c.
[0619] Further, as a configuration in which the measurement outlet
33c is provided on the curved surface 45, there is a configuration
in which the measurement outlet 33c is disposed at an intermediate
position of the outer peripheral inclined surface in the depth
direction Z. For example, as shown in FIG. 86, the measurement
outlet 33c is disposed between the outer peripheral upstream end
132a and the vertical boundary 131a. In the above configuration,
the upstream end portion of the upstream tapered surface 404 is
included in the outer peripheral upstream end 132a, the downstream
end portion of the upstream tapered surface 404 is included in the
vertical boundary 131a, and the measurement outlet 33c is disposed
at a position closer to the vertical boundary 131a in the depth
direction Z. Also, in the above configuration, similarly to
Modification B11, the forward flow air flows along the upstream
tapered surface 404 as the outer peripheral inclined surface before
reaching the measurement outlet 33c, so that the forward flow air
does not easily flow into the measurement outlet 33c.
[0620] From the viewpoint that the forward flow air hardly flows
into the measurement outlet 33c, it is preferable that the
measurement outlet 33c is placed as far as possible from the
upstream end portion of the upstream tapered surface 404 or the
outer peripheral upstream end 132a. For that reason, in the depth
direction Z, it is preferable that a separation distance L18
between the vertical boundary 131a and the measurement outlet 33c
is smaller than a length dimension L13 of the measurement outlet
33c.
[0621] The measurement outlet 33c may be disposed at a position
closer to the outer peripheral upstream end 132a in the depth
direction Z. Even, in this case, the measurement outlet 33c and the
outer peripheral upstream end 132a are separated from each other in
the depth direction Z, thereby being capable of making it difficult
for the forward flow air to flow into the measurement outlet
33c.
[0622] As Modification B4, the measurement outlet may be provided
only on the outer peripheral flat surface out of the outer
peripheral flat surface and the outer peripheral inclined surface.
For example, in the first embodiment, the measurement outlet 33c is
provided on the flat surface 44 so as not to protrude from the
curved surface 45. In the above configuration, the measurement
outlet 33c does not extend across the vertical boundary 131a in the
depth direction Z, but extends from the vertical boundary 131a
toward the outer peripheral downstream end 132b in the depth
direction Z, and the outlet upstream end 134a of the measurement
outlet 33c is included in the vertical boundary 131a. Also, in the
above configuration, if the outlet downstream end 134b of the
measurement outlet 33c and the downstream end portion of the flat
surface 44 are separated from each other in the depth direction Z,
even if the turbulence of the air flow occurs in the periphery of
the downstream end portion of the flat surface 44 or the periphery
of the outer peripheral downstream end 132b, the turbulence can be
inhibited from reaching the measurement outlet 33c.
[0623] Further, as shown in FIG. 120, the measurement outlet 33c is
provided on the flat surface 44 so as not to protrude from the
upstream tapered surface 404 as the outer peripheral inclined
surface. In the above configuration, as in FIG. 85, the upstream
tapered surface 404 is included in the outer peripheral surface of
the housing 21 instead of the curved surface 45, and the boundary
between the upstream tapered surface 404 and the flat surface 44 is
the vertical boundary 131a. Also, in the above configuration, the
outlet upstream end 134a of the measurement outlet 33c is included
in the vertical boundary 131a.
[0624] Further, as a configuration in which the measurement outlet
33c is provided on the flat surface 44, there is a configuration in
which the measurement outlet 33c is disposed at an intermediate
position of the flat surface 44 in the depth direction Z. For
example, as shown in FIG. 87, the measurement outlet 33c is
disposed between the vertical boundary 131a and the outer
peripheral downstream end 132b. In the above configuration, the
upstream end portion of the flat surface 44 is included in the
vertical boundary 131a, the downstream end portion of the flat
surface 44 is included in the outer peripheral downstream end 132b,
and the measurement outlet 33c is disposed at a position close to
the vertical boundary 131a in the depth direction Z. Also, in the
above configuration, similarly to Modification B13 described above,
even if the turbulence of the air flow occurs in the periphery of
the downstream end portion of the flat surface 44 or the periphery
of the outer peripheral downstream end 132b, the turbulence can be
inhibited from reaching the measurement outlet 33c.
[0625] From the viewpoint of inhibiting the turbulence of the air
flow generated in the downstream side of the measurement outlet 33c
from reaching the measurement outlet 33c, it is preferable that the
measurement outlet 33c is placed as far as possible from the
downstream end portion of the flat surface 44 or the outer
peripheral downstream end 132b. For that reason, in the depth
direction Z, it is preferable that a separation distance L19
between the vertical boundary 131a and the measurement outlet 33c
is smaller than a length dimension L13 of the measurement outlet
33c.
[0626] As Modification B5, in the first embodiment, the discharge
path 32c of the measurement flow channel 32 may be narrowed toward
the housing base end side in the height direction Y. For example,
as shown in FIG. 88, a bulging region 406 in which a part of the
discharge path 32c is bulged in the depth direction Z is included
in the measurement flow channel 32. The bulging region 406 bulges
toward the introduction path 32b side so as to keep a state in
which the discharge path 32c and the introduction path 32b are
separated from each other by the longitudinal partition wall 69,
and is disposed at the end portion of the discharge path 32c on the
housing tip side. The measurement outlet 33c has a portion 407a
that opens the entirety of the bulging region 406 in the width
direction X, and a portion 407b that protrudes from the
longitudinal partition wall 69 toward the opposite side of the
introduction path 32b. In this case, unlike the present
modification, an open area of the measurement outlet 33c becomes
large as compared with the configuration in which the measurement
flow channel 32 does not have the bulging region 406, so that the
discharge amount of the intake air from the measurement outlet 33c
can be increased. As a result, a flow velocity of the air in the
measurement flow channel 32 increases, so that the measurement
accuracy of the flow rate detector 22 can be improved.
[0627] As Modification B6, in each of the embodiments described
above such as the first embodiment, the flat surface 44 and the
curved surface 45 may be included in the end face on the housing
tip side or the end face on the housing base end side in the outer
peripheral surface of the housing 21. In this case, the measurement
outlet 33c is provided on the end face on the housing tip side and
the end face on the housing base end side in the housing 21.
[0628] As Modification B7, in each of the embodiments described
above, the positional relationship between the flat surface 44 and
the curved surface 45 is not limited to the embodiments described
above as long as the measurement outlet 33c is located at a
position extending across the flat surface 44 and the curved
surface 45. For example, in the first embodiment, the flat surface
44 may have at least one of the downstream flat portion 137a, the
tip-side flat portion 137b, and the base end-side flat portion
137c. The curved surface 45 may have at least one of the upstream
curved portion 138a, the tip-side curved portion 138b, and the base
end-side curved portion 138c. In short, the flat surface 44 and the
curved surface 45 may be disposed so that the vertical boundary
131a extends in the height direction Y. The vertical boundary 131a
may be inclined with respect to the height direction Y.
[0629] As Modification B8, in each of the embodiments described
above such as the first embodiment, the measurement outlet 33c may
be disposed at a position of extending across the outer peripheral
upstream end 132a in the width direction X on the outer peripheral
surface of the housing 21. Even in this case, since the open area
of the measurement outlet 33c is smaller than the open area of the
inflow port 33a, a configuration can be realized in which the
forward flow air hardly flows into the measurement outlet 33c.
[0630] As Modification B9, in the first embodiment, as shown in
FIGS. 6 and 7, and the like, the thinned portions 41 may be
provided on the flat surface 44. Even in this case, if the
measurement outlet 33c and the thinned portions 41 are separated
from each other in the depth direction Z, even if the turbulence of
the air flow occurs around the thinned portions 41, the turbulence
can be inhibited from reaching the measurement outlet 33c.
[0631] As Modification B10, in the first embodiment, the downstream
defining surface 135b may be a curved surface instead of a tapered
surface. In short, the downstream defining surface 135b may be an
inclined surface inclined with respect to the flat surface 44.
Further, in the configuration in which the downstream defining
surface 135b is a curved surface, the curved surface may be curved
so as to project toward the outer peripheral side of the housing
21, or may be curved so as to be recessed toward the inner
peripheral side of the housing 21.
[0632] <Modifications of Configuration Group C>
[0633] As Modification C1, in the first embodiment, the
accommodation wall portion 121 may not be a position holder. For
example, as shown in FIG. 89, the housing body 24 has a positioning
portion 411, and the positioning portion 411 protrudes from the
accommodation wall portion 121 toward the inner peripheral side. In
the above configuration, the housing body 24 does not have the
overhanging portion 66a, and the accommodation wall portion 121
extends from the sealing wall portion 122 toward the housing tip
side. For that reason, in the height direction Y, the boundary
between the accommodation wall portion 121 and the sealing wall
portion 122 coincides with the boundary between the sealing region
PA and the accommodation region PB1.
[0634] The positioning portion 411 extends along the inner
peripheral surface of the accommodation wall portion 121, and is
disposed at the end portion of the accommodation wall portion 121
on the housing base end side. The positioning portion 411 is formed
in a plate shape, and the plate surface 411a on the housing base
end side in the positioning portion 411 comes in contact with the
circuit step surface 55 of the sensor SA 50, similarly to the
region step surface 66 of the first embodiment. The plate surface
411a restricts the sensor SA 50 from moving toward the housing tip
side, and corresponds to a third holding portion. The tip end face
411b of the positioning portion 411 comes in contact with the outer
peripheral surface of the junction portion 52 of the sensor SA 50,
similarly to the tip end faces of the housing protrusions 72a and
72b of the first embodiment, thereby restricting the sensor SA 50
from moving in the width direction X and the depth direction Z. A
portion of the tip end face 411b which faces in the width direction
X corresponds to a first holding portion, and a portion which faces
in the depth direction Z corresponds to a second holding
portion.
[0635] The positioning portion 411 is provided at a position
separated from the ring holding portion 25 toward the housing tip
side. In this case, even if deformation due to resin molding occurs
in the ring holding portion 25 and the sealing wall portion 122, it
is considered that the deformation is absorbed in a portion between
the ring holding portion 25 and the positioning portion 411 in the
housing body 24. For that reason, the position and shape of the
positioning portion 411 hardly changes with the deformation of the
ring holding portion 25 and the sealing wall portion 122, as a
result of which, the positional deviation of the flow rate detector
22 is inhibited.
[0636] As Modification C2, in the modification C1, the positioning
portion 411 may be formed of a member different from the housing
body 24. For example, as shown in FIGS. 90 and 91, the positioning
member 412 forming the positioning portion 411 is attached to the
housing body 24. Unlike the housing body 24, the positioning member
412 is formed of a conductive metal material or the like. Since the
positioning member 412 has conductivity in this manner, static
electricity charged in the housing body 24 having insulating
properties is easily discharged by the positioning member 412. For
that reason, the detection accuracy of the flow rate detector 22
can be inhibited from being lowered by static electricity.
[0637] The positioning member 412 has a depth portion 412a
extending in the depth direction Z and a pair of width portions
412b extending in the width direction X, and each width portion
412b extends in the same direction from both ends of the depth
portion 412a. In the positioning member 412, the plate surface 411a
that comes in contact with the circuit step surface 55 of the
sensor SA 50 is formed by the respective plate surfaces of the
depth portion 412a and the width portions 412b. A tip end face 411b
that comes in contact with the outer peripheral surface of the
junction portion 52 of the sensor SA 50 is formed by the inner
peripheral surface of the positioning member 412.
[0638] A support recess portion 413 for supporting the positioning
member 412 is provided on the inner peripheral surface of the
housing body 24. The support recess portion 413 is a recess portion
recessed toward the outer peripheral side, and extends in a groove
shape along the end portion of the housing base end side of the
accommodation wall portion 121. The positioning member 412 is
fitted into the support recess portion 413 with its outer
peripheral end entering the support recess portion 413, and the
positioning member 412 and the housing body 24 are bonded to each
other by an adhesive or the like. The depth portion 412a of the
positioning member 412 is disposed on the front surface side of the
sensor SA 50, and is not disposed on the back surface side.
[0639] The housing 21 is not integrally molded as in the first
embodiment, but is formed by assembling multiple members as in the
fourth embodiment. For example, after the multiple members are each
molded with resin and the positioning member 412 is molded with
metal, the multiple members are assembled to each other so that the
positioning member 412 is accommodated in the internal space
24a.
[0640] According to the present modification, since the positioning
member 412 is a member separate from the housing body 24, the
degree of freedom of selection of the material forming the
positioning portion 411 can be increased. In addition, even when
the shape and size are changed in accordance with a change in the
specifications of the sensor SA 50, the existing housing 21 can be
used by changing the shape and size of the positioning member
412.
[0641] As Modification C3, the sensor SAs 50 and 220 as detection
units may include multiple physical quantity detectors. For
example, in the fourth embodiment, the sensor SA 220 has two
physical quantity detectors for detecting physical quantities that
differ from each other. As shown in FIG. 92, the sensor SA 220 with
the above configuration has a first detector 421 for detecting the
flow rate of an air and a second detector 422 for detecting the
temperature of the air as physical quantity detectors. As with the
flow rate detector 202 according to the fourth embodiment, the
first detector 421 is provided in the measurement flow channel 32
to detect the flow rate of the intake air in the measurement flow
channel 32. As with the intake air temperature sensor 23 according
to the first embodiment, the second detector 422 is provided
outside the housing 201, to thereby detect the temperature of the
intake air in the intake passage 12.
[0642] The sensor SA 220 includes a first support portion 423 that
supports the first detector 421 and a second support portion 424
that supports the second detector 422. The first support portion
423 extends from the SA base portion 221 toward the housing tip
side similarly to the detection support portion 223 in the fourth
embodiment. The second support portion 424 extends from the SA base
portion 221 toward the upstream wall portion 231 in the depth
direction Z, and is disposed at a position closer to the end of the
SA base portion 221 on the housing tip side. An outer peripheral
insertion portion 426 into which the second support portion 424 is
inserted is provided at the outer peripheral portion of the housing
body 204, and the second detector 422 is disposed at a portion of
the second support portion 424 exposed to the outside of the
housing through the outer peripheral insertion portion 426.
[0643] The housing body 204 is provided with a housing recess
portion 427 whose outer peripheral surface is formed to be recessed
toward the downstream side. The housing recess portion 427 is
disposed at an intermediate position of the housing body 204 in the
height direction Y. In the upstream wall portion 231, the portion
connecting the first regulation portion 251 and the second
regulation portion 255 in the fourth embodiment is not provided.
Instead of that portion, a regulating connection portion 428 for
connecting the first regulation portion 251 and the second
regulation portion 255 is provided at a position closer to the
downstream wall portion 232 than the upstream wall portion 231, and
a bottom surface of the housing recess portion 427 is formed by the
outer peripheral surface of the regulating connection portion 428.
Like the first regulation portion 251 and the second regulation
portion 255, the regulating connection portion 428 is included in
the base member 261, and is integrally molded with the regulation
portions 251 and 255 and the like.
[0644] The outer peripheral insertion portion 426 is provided in
the regulating connection portion 428. The outer peripheral
insertion portion 426 is a through hole that penetrates through the
regulating connection portion 428 in the depth direction Z, and an
inner peripheral surface 426a of the outer peripheral insertion
portion 426 comes in contact with the outer peripheral surface of
the second support portion 424. In this case, the movement of the
second support portion 424 in the width direction X and the height
direction Y is restricted by the inner peripheral surface 426a of
the outer peripheral insertion portion 426, and the inner
peripheral surface 426a can be referred to as a positioning
surface. The downstream-side plate surface of the regulating
connection portion 428 is in contact with the outer peripheral
surface of the SA base portion 221. In this instance, the movement
of the sensor SA 220 toward the upstream side is regulated by the
downstream-side plate surface of the regulating connection portion
428, and the downstream-side plate surface can be referred to as a
positioning surface.
[0645] Further, as shown in FIG. 92, the housing 201 does not need
to have the sealing member 206. Even in this case, the housing
attachment is configured by the flange portion 207, and the wall
thickness of the housing attachment is not changed. The housing
attachment does not necessarily have to be thicker than the
accommodation wall portion 121.
[0646] As Modification C4, in the fourth embodiment, the first
regulation portion 251 and the second regulation portion 255 may be
formed of a member different from the housing body 204. For
example, a first regulation member forming the first regulation
portion 251 is attached to the housing body 204. In the above
configuration, the first regulation member is formed in a plate
shape. A support recess portion for supporting the first regulation
member is formed on the inner peripheral surface of the housing
body 204, and the outer peripheral end of the first regulating
member is fitted in the support recess portion. The first
regulation member is made of a conductive metal material or the
like. Since the first regulation member has conductivity in this
manner, static electricity charged in the housing body 204 having
insulating properties is easily discharged by the first regulating
member. For that reason, the detection accuracy of the flow rate
detector 202 can be inhibited from being lowered by static
electricity.
[0647] As Modification C5, in the first embodiment, the depth
housing protrusion 72b of the housing body 24 may have the function
of only one of the first holding portion and the second holding
portion. For example, in the SA side surface 126, the depth housing
protrusion 72b is in contact with a portion orthogonal to the depth
direction Z. The depth housing protrusion 72b with the above
configuration holds the sensor SA 50 in position in the depth
direction Z, and has the function of the first holding portion, but
does not have the function of the second holding portion.
[0648] In addition, the width housing protrusion 72a may have the
functions of both the first holding portion and the second holding
portion. For example, the width housing protrusion 72a comes in
contact with a portion of the outer peripheral surface of the
sensor SA 50 inclined in both the width direction X and the depth
direction Z. The width housing protrusion 72a with the above
configuration holds the sensor SA 50 in position in both the width
direction X and the depth direction Z, and has the functions of
both the first holding portion and the second holding portion.
[0649] As Modification C6, the third holding portion may have at
least one function of the first holding portion and the second
holding portion. For example, in the first embodiment, the region
step surface 66 of the housing body 24 is not orthogonal to the
height direction Y, but inclined with respect to the height
direction Y. In the above configuration, the region step surface 66
is inclined with respect to the width direction X and the depth
direction Z so as to face the inner peripheral side, and the
circuit step surface 55 of the sensor SA 50 is inclined with
respect to the width direction X and the depth direction Z so as to
face the outer peripheral side. In this instance, since the circuit
step surface 55 enters the inside of the region step surface 66 and
the circuit step surface 55 comes in contact with the region step
surface 66, the sensor SA 50 is restricted from moving not only in
the height direction Y but also in the width direction X and the
depth direction Z. For that reason, the region step surface 66 has
the functions of the first holding portion and the second holding
portion in addition to the function of the third holding portion.
The circuit step surface 55 and the region step surface 66 may be
inclined by a tapered surface or may be inclined by a curved
surface.
[0650] As Modification C7, in the detection units which are the
sensor SAs 50 and 220, the portion that comes in contact with the
position holder of the housing does not have to be located closer
to the physical quantity detector such as the flow rate detectors
22 and 202 in the detection unit. For example, in the first
embodiment, the separation distance L3 between the flow rate
detector 22 and the circuit step surface 55 may be larger than the
separation distance L4 between the base end portion of the sensor
SA 50 and the circuit step surface 55.
[0651] As Modification C8, the physical quantity measurement device
may be fixed to the intake pipe 12a through no sealing member such
as the O-ring 26 or the sealing member 206. For example, the
housing has a housing fitting portion that fits into the airflow
insertion hole 12b, and the outer peripheral surface of the housing
fitting portion and the inner peripheral surface of the airflow
insertion hole 12b are in close contact with each other. In the
above configuration, the housing fitting portion is included in the
housing attachment, and the position holders such as the
accommodation wall portion 121 and the first regulation portion 251
are provided closer to the housing tip side than the housing
fitting portion.
[0652] As Modification C9, the entire portion of the housing which
does not enter the intake passage 12 may be the housing attachment.
For example, in the fourth embodiment, in addition to the sealing
holder 205 and the flange portion 207, a portion of the housing 201
which does not enter the intake passage 12 is also included in the
housing attachment. In the above configuration, a portion of the
housing body 204 facing the inner peripheral surface of the airflow
insertion hole 12b and the inner peripheral surface of the pipe
flange 12c is included in the housing attachment. Also, in the
above configuration, if the first regulation portion 251 as the
position holder is located closer to the housing tip side than the
housing attachment, even if deformation due to resin molding occurs
in the housing attachment, the position and shape of the first
regulation portion 251 due to the deformation can be inhibited from
being unintentionally changed.
[0653] As Modification C10, the housing opening may be opened in
the depth direction Z. For example, in the fourth embodiment, the
housing opening 241 is provided in the upstream wall portion 231 or
the downstream wall portion 232 of the housing body 204. Also, in
the above configuration, the sensor SA 220 can be inserted into the
internal space 204a from the housing opening 241, and the
thermosetting resin can be injected into the internal space 204a
from the housing opening 241.
[0654] As Modification C11, three or more members may be assembled
to each other when forming the housing. For example, in the fourth
embodiment, two cover members, that is, a front cover member and a
back cover member, are assembled to the base member 261. In the
above configuration, the front cover member is a cover member 262,
and the back cover member is a member having at least a part of the
back wall portion 234 of the housing body 204.
[0655] As Modification C12, not all of the detection units, which
are the sensor SAs 50 and 220, may be accommodated in the internal
space of the housing. In other words, at least a part of the
detection unit may be accommodated in the internal space. For
example, in the first embodiment, the tip portions of the lead
terminals 54 of the sensor SA 50 protrude to the outside through
the housing opening 61. Also, in the above configuration, the
member covering the lead terminals 54 is attached to the housing
21, so that the lead terminals 54 and the connector terminals 28a
can be protected.
[0656] As Modification C13, the position holder such as the
accommodation wall portion 121 and the first regulation portion 251
may be provided closer to the housing base end side than the
housing attachment as long as the position holder is separated from
the housing attachment in the housing. Also, in the above
configuration, since the position holder and the housing attachment
are separated from each other, even if deformation due to resin
molding occurs in the housing attachment, the position and shape of
the position holder can be inhibited from changing due to the
deformation.
[0657] As Modification C14, a physical quantity detector for
detecting a physical quantity different from the flow rate of the
intake air may be provided in the measurement flow channel.
Examples of the physical quantity detector provided in the
measurement flow channel include a detector for detecting a
temperature, a detector for detecting a humidity, a detector for
detecting a pressure, and the like in addition to the flow rate
detectors 22 and 202. Those detectors may or may not be mounted on
the sensor SAs 50 and 220 as the detection units. The physical
quantity detector not mounted on the detection unit may be attached
to the inner peripheral surface of the measurement flow channel, or
may be attached to a projection portion or the like protruding from
the inner peripheral surface of the measurement flow channel. In
addition, the physical quantity detector may be provided in the
bypass flow channels 30 and 210, not in the measurement flow
channel. In other words, the physical quantity detector may be
provided in the passage flow channel.
[0658] <Modification of Configuration Group D>
[0659] As Modification D1, the mold device may have multiple
passage mold portions for molding the passage flow channel. For
example, in the first embodiment, as shown in FIGS. 93 and 94, the
passage flow channel 31 of the housing 21 is molded by the passage
mold portions 431a and 431b.
[0660] The passage flow channel 31 with the above configuration has
a throttle passage portion 433 provided between the inflow passage
31a and the outflow passage 31b. While the throttle passage portion
433 narrows the passage flow channel 31 toward the outflow port
33b, the outflow passage 31b does not narrow the passage flow
channel 31 toward the outflow port 33b. For example, the inner
peripheral surface of the throttle passage portion 433 includes the
wall throttle surface 153a, while the inner peripheral surface of
the outflow passage 31b does not include the wall throttle surface
153a. When the boundary between the throttle passage portion 433
and the outflow passage 31b is referred to as a throttle boundary
434, the passage flow channel 31 is not narrowed from the throttle
boundary 434 toward either the inflow port 33a or the outflow port
33b.
[0661] The mold device 90 has an inflow passage mold portion 431a
and an outflow passage mold portion 431b instead of the passage
mold portion 104 of the first embodiment. In the mold device 90,
the passage mold portions 431a and 431b abut against each other and
also abut against the measurement molding portion 97. The inflow
passage mold portion 431a and the outflow passage mold portion 431b
abut against each other at their respective tip end faces, and the
surfaces of the respective housing base end sides of the passage
mold portions 431a and 431b abut against the tip end face of the
measurement molding portion 97.
[0662] The inflow passage mold portion 431a and the outflow passage
mold portion 431b do not thicken toward the respective tip end
faces. For that reason, when the mold device 90 is removed from the
resin molded housing 21, the inflow passage mold portion 431a can
be extracted from the inflow port 33a, and the outflow passage mold
portion 431b can be extracted from the outflow port 33b. The inflow
passage mold portion 431a corresponds to an inflow mold portion,
and the outflow passage mold portion 431b corresponds to an outflow
mold portion.
[0663] According to the above modification, in the passage flow
channel 31, a portion closer to the inflow port 33a side than the
throttle boundary 434 is molded by the inflow passage mold portion
431a, and a portion closer to the outflow port 33b side than the
throttle boundary 434 is molded by the outflow passage mold portion
431b. For that reason, there is no need to extract the inflow
passage mold portion 431a from the outflow port 33b, and there is
no need to extract the outflow passage mold portion 431b from the
inflow port 33a, so that the degree of freedom in design and
manufacturing relating to the shape and size of the passage flow
channel 31 can be enhanced. Moreover, since the inflow passage mold
portion 431a can be extracted from the inflow port 33a and the
outflow passage mold portion 431b can be extracted from the outflow
port 33b, the inner peripheral surface of the passage flow channel
31 can be integrally molded.
[0664] As Modification D2, in the configuration in which the
positional deviation between the passage mold portion and the
measurement mold portion is regulated by fitting the mold
projection portion into the mold recess portion, either the passage
mold portion or the measurement mold portion may have the mold
projection portion. For example, in the fifth embodiment, the
measurement molding portion 97 has the mold projection portion 334,
and the passage mold portion 104 has the mold recess portion 335,
but the measurement molding portion 97 may have the mold recess
portion 335, and the passage mold portion 104 may have the mold
projection portion 334.
[0665] For example, in the first embodiment, as shown in FIG. 95,
the tip end face of the passage mold portion 104 does not abut
against the outer peripheral mold portions 102 and 103 but abuts
against the measurement molding portion 97. In the above
configuration, in a state before the mold device 90 is removed from
the resin molded housing 21, the measurement molding portion 97 is
inserted between the passage mold portion 104 and the outer
peripheral mold portions 102 and 103 in the passage flow channel
31, and the tip end face of the passage mold portion 104 and the
side surface of the measurement molding portion 97 abut against
each other. In the abutment portion, the mold projection portion
334 is provided on the tip end face of the passage mold portion
104, and the mold recess portion 335 is provided on the side
surface of the measurement molding portion 97. In this case, unlike
the first embodiment, the measurement molding portion 97 is removed
from the housing 21 after the passage mold portion 104 has been
extracted from the inflow port 33a.
[0666] The configuration in which the mold projection portion fits
into the mold recess portion may be applied to Modification D1
described above. For example, the mold recess portion 335 is
provided in each of the inflow passage mold portion 431a and the
outflow passage mold portion 431b, and the mold projection portion
334 fitted in each of the mold recess portions 335 of the passage
mold portions 431a and 431b is provided in the measurement molding
portion 97. One of the mold projection portion and the mold recess
portion may be provided in the inflow passage mold portion 431a,
and the other may be provided in the outflow passage mold portion
431b. In this case, the position deviation can be restricted
between the inflow passage mold portion 431a and the outflow
passage mold portion 431b in the width direction X and the height
direction Y.
[0667] As Modification D3, in the fifth embodiment, the mold recess
portion 335 does not have to surround the four sides of the mold
projection portion 334. For example, the mold recess portion 335 is
opened in the width direction X in the passage mold portion 104. In
the above configuration, the mold recess portion 335 is a groove
portion extending in the width direction X on the inner passage
surface 159, and the mold projection portion 334 is shaped to
extend along the groove portion. Also, in the above configuration,
the mold projection portion 334 enters the mold recess portion 335,
thereby restricting the relative movement between the passage mold
portion 104 and the measurement molding portion 97 in the depth
direction Z.
[0668] As Modification D4, the inflow port may be opened in a
direction inclined with respect to the depth direction Z. For
example, the inflow port may be opened obliquely to the side
opposite to the housing base end side. For example, in the fifth
embodiment, as shown in FIG. 96, in the depth direction Z, the
upstream end portion of the passage floor surface 152 is disposed
at a position closer to the outflow port 33b than the upstream end
portion of the passage ceiling surface 151.
[0669] In the above configuration, as compared with the fifth
embodiment, the length dimension of the passage floor surface 152
is reduced in the depth direction Z, and the passage floor surface
152 is also reduced in the height direction Y by an amount
corresponding to the reduction. For that reason, compared with the
fifth embodiment, the height dimension of the inflow port 33a in
the height direction Y is reduced, and a foreign matter is less
likely to enter from the inflow port 33a by the amount of the
reduction.
[0670] In the configuration in which the floor throttle surface
152a is included in the passage floor surface 152, it is considered
that there is a foreign matter that can easily enter the
measurement flow channel 32 instead by changing the direction of
advancing against the floor throttle surface 152a. On the other
hand, in the present modification, it is assumed that as the
passage floor surface 152 is longer in the depth direction Z, the
possibility that the advancing direction of the foreign matter is
changed to the direction in which the foreign matter easily enters
the measurement flow channel 32 is higher, and the portion disposed
in the height direction Y is not provided at the upstream end
portion of the passage ceiling surface 151 in the floor throttle
surface 152a. In other words, in the floor throttle surface 152a, a
portion having a high possibility of changing the advancing
direction of the foreign matter to a direction in which the foreign
matter easily enters the measurement flow channel 32 is deleted.
This makes it possible to inhibit the foreign matter that has
abutted against the floor throttle surface 152a from entering the
measurement flow channel 32.
[0671] As Modification D5, the flow channel boundary portion 34
does not have to face the outflow port 33b side. For example, in
the first embodiment, the flow channel boundary portion 34 extends
in the depth direction Z similarly to the passage ceiling surface
151. In the above configuration, in the mold device 90, the
boundary between the measurement molding portion 97 and the passage
mold portion 104 coincides with the flow channel boundary portion
34.
[0672] As Modification D6, the passage mold portion may be
extracted from the outflow port instead of the inflow port. For
example, in the first embodiment, the passage mold portion 104 is
extracted from the outflow port 33b. In the above configuration,
the passage mold portion 104 is not thickened toward the tip
portion of the passage mold portion 104 in the same manner as in
the first embodiment, but the direction in which the passage mold
portion 104 is assembled to the outer peripheral mold portions 102
and 103 is opposite to that in the first embodiment. Further, the
passage flow channel 31 is configured not to be narrowed from the
inflow port 33a toward the outflow port 33b, contrary to the first
embodiment.
[0673] As Modification C7, in the fifth embodiment, the inclination
angle 83 in the passage floor surface 152 may not be uniform
depending on the location. Even in the above case, assuming a
virtual line in which the upstream end portion and the downstream
end portion of the passage floor surface 152 are connected straight
to each other, the inclination angle of the virtual line with
respect to the inflow ceiling portion 332a is larger than the
inclination angle 82 of the flow channel boundary portion 34, so
that a configuration in which the passage mold portion 104 can be
extracted from the inflow port 33a can be realized.
[0674] <Modifications of Configuration Group E>
[0675] As Modification E1, in the fourth embodiment, the air flow
meter 200 may have a terminal support portion that supports the
connector terminal 208a in the connector region QC. For example, as
shown in FIGS. 97 to 99, in the connector region QC, a back support
portion 441 as a terminal support portion is provided between the
second terminal portion 282b and the back wall portion 234. The
back support portion 441 is formed of a synthetic resin material in
a plate shape, and is bonded to the back wall portion 234 by an
adhesive or the like in a state of being superposed on the inner
peripheral surface of the back wall portion 234. The second
terminal portion 282b abuts against the plate surface of the back
support portion 441 on the housing opening 241 side. In this case,
the back support portion 441 supports the second terminal portion
282b from the side opposite to the housing opening 241.
[0676] The back support portion 441 is extended to the second
terminal portion 282b and the lead terminal 224 in the height
direction Y. In other words, the back support portion 441 is
provided at a position of extending across the boundary between the
second terminal portion 282b and the lead terminal 224 in the
height direction Y. As with the second terminal portion 282b, the
lead terminal 224 is in contact with the plate surface of the back
support portion 441 on the housing opening 241 side. In this case,
in addition to the second terminal portion 282b, the back support
portion 441 supports the lead terminals 224 from the side opposite
to the housing opening 241.
[0677] In the housing 201, the SA main body 225 of the sensor SA
220 is caught by the back wall 234, and the wall surface 283 of the
back wall portion 234 on the housing opening 241 maintains the
position of the sensor SA 220. In the back support portion 441, the
lead terminal 224 of the sensor SA 220 is caught by the back
support portion 441, and the plate surface 441a of the back support
portion 441 on the side of the housing opening 241 holds the
position of the lead terminal 224. In this case, the wall surface
283 corresponds to a unit holding surface, and the plate surface
441a corresponds to a terminal holding surface.
[0678] The back support portion 441 may be made of a metal
material. The back support portion 441 may be formed by a part of
the housing 201. For example, the back support portion 441 is
formed by a projection portion in which the back wall portion 234
of the housing 201 protrudes toward the housing opening 241 side.
In the above configuration, the tip end face of the projection
portion is the plate surface 411a of the back support portion 441,
and corresponds to a terminal holding surface.
[0679] According to the present modification, in the connector
region QC, the second terminal portion 172b is supported by the
back support portion 441 from the side opposite to the housing
opening 241. For that reason, the second terminal portion 172b is
less likely to be unintentionally deformed or displaced. In this
case, the second terminal portion 282b is displaced from the lead
terminal 224, thereby being capable of inhibiting the second
terminal portion 282b and the lead terminal 224 from being properly
joined to each other.
[0680] According to the present modification, the lead terminal 224
inserted between the housing opening 241 and the back support
portion 441 is supported by the back support portion 441 from the
side opposite to the housing opening 241. For that reason, the lead
terminal 224 is less likely to be unintentionally deformed or
displaced. This makes it possible to inhibit that the second
terminal portion 282b and the lead terminal 224 cannot be properly
joined to each other due to the positional deviation of the lead
terminals 224 with respect to the second terminal portion 282b.
[0681] According to the present modification, the plate surface
441a of the back support portion 441 supporting the lead terminal
224 of the sensor SA 220 is disposed at a position closer to the
housing opening 241 than the wall surface 283 of the back wall
portion 234 supporting the SA main body 225. In this case, since
there is no need to insert the joining tool deeper than the plate
surface 441a when the second lead portion 342 and the lead
terminals 224 are joined to each other, the joining tool can be
inhibited from unintentionally coming in contact with the housing
201.
[0682] As Modification E2, in the fourth embodiment, in the
connection portion between the connector terminal 208a and the lead
terminal 224, the connector terminal 208a and the lead terminal 224
may be aligned not in the width direction X and the depth direction
Z but in the height direction Y. For example, as shown in FIGS. 97
and 98, each of the second terminal portion 282b and the lead
terminal 224 extends toward the housing opening 241.
[0683] The second terminal portion 282b configured as described
above has a terminal extending portion 443a extending from the
sealing holder 205, and a terminal rising portion 443b rising from
the terminal extending portion 443a toward the housing opening 241.
The lead terminal 224 has a lead extending portion 444a extending
from the SA main body 225, and a lead rising portion 444b rising
from the lead extending portion 444a toward the housing opening
241. The lead rising portion 444b extends in the width direction X
along the terminal rising portion 443b, and is joined to the
terminal rising portion 443b by welding or the like. The terminal
rising portion 443b corresponds to a vertical terminal portion.
[0684] According to the above modification, the terminal rising
portion 443b extends from the back support portion 441 toward the
housing opening 241. In this case, when the lead rising portion
444b and the terminal rising portion 443b are sandwiched between a
joining tool such as welding electrodes or the like, there is no
need to insert the joining tool into the back side of the lead
rising portion 444b and the terminal rising portion 443b from the
housing opening 241. For that reason, when the lead rising portion
444b and the terminal rising portion 443b are joined to each other
with the use of the joining tool, the joining operation can be
facilitated.
[0685] As Modification E3, in the fourth embodiment, the lead
terminal 224 and the connector terminal 208a may have a vent 445 as
a bent portion. For example, as shown in FIG. 98, the lead
extending portion 444a of the lead terminal 224 and the terminal
extending portion 443a of the connector terminal 208a each have the
vent 445. As shown in FIG. 99, each of the lead terminal 224 and
the second terminal portion 282b has the vent 445. In either
configuration, stresses applied to the lead terminal 224 and the
connector terminal 208a can be reduced by the vents 445.
[0686] As Modification E4, similarly to Modification C3, the sensor
SAs 50 and 220 as the detection units may have multiple physical
quantity detectors. In Modification C3 described above, in the
fourth embodiment, a configuration is exemplified in which the
first detector 421 is provided inside the housing 201, and the
second detector 422 is provided outside the housing 201. On the
other hand, in the present modification, a configuration in which
both the first detector 421 and the second detector 422 are
provided inside the housing 201 will be exemplified. For example,
in the fourth embodiment, as shown in FIGS. 100 and 101, the first
detector 421 is disposed on the plate surface on the housing
opening 241 side in the sensor SA 220, and the second detector 422
is disposed on the plate surface on the other side to the housing
opening 241. In the above configuration, the first detector 421
faces the front wall portion 233, and the second detector 422 faces
the back wall portion 234.
[0687] As Modification E5, in the fourth embodiment, the sensor SA
220 and the cover member 262 may be assembled to each other, and
the sensor SA 220 and the cover member 262 may be collectively
attached to the base member 261. For example, as shown in FIG. 102,
a cover unit 447 is formed by assembling the sensor SA 220 and the
cover member 262 to each other, and the cover unit 447 is attached
to the base member 261. According to the above configuration, the
number of components can be reduced and the structure of the air
flow meter 200 can be simplified.
[0688] As Modification E6, the internal space of the housing may be
sealed by the cover member. For example, in the first embodiment,
as shown in FIG. 103, the internal space 24a of the housing 21 is
sealed by the cover member 448. In the above configuration, the
potting portion 65 is not formed because the internal space 24a is
not filled with a thermosetting resin. The cover member 448 is a
separate member that is resin molded independently of the housing
21, and is fitted into the housing opening 61. The internal space
24a may be sealed by both the potting portion 65 and the cover
member 448. For example, after the potting portion 65 has been
formed by filling the internal space 24a with the thermosetting
resin, the cover member 448 is attached to the housing opening
61.
[0689] In the fourth embodiment, as shown in FIGS. 104 and 105, the
internal space 204a of the housing 201 is sealed with a cover
member 449. In the above configuration, a portion of the open
portion of the base member 261, which is not closed by the cover
member 262, is not the housing opening 241 as in the fourth
embodiment, but the entire open portion of the base member 261 is
the housing opening 241. The cover member 449 is fitted into the
housing opening 241 to close the entire housing opening 241. The
internal space 204a may be sealed by both the potting portion 242
and the cover member 449. For example, after the potting portion
242 has been formed by filling the internal space 204a with a
thermosetting resin, the cover member 262 is attached to the
housing opening 241.
[0690] As Modification E7, the connector terminal may protrude into
the main body region. Even in this case, if the connector terminal
does not enter between the detection unit and the housing opening
in the direction in which the detection unit and the housing
opening are aligned, the connector terminal does not hinder the
insertion of the detection unit into the internal space of the
housing. For example, in the first embodiment, the connector
terminals 28a protrudes into the main body region PC1, so that the
second terminal portion 172b is disposed in the main body region
PC1. Also, in the above configuration, the second terminal portion
172b does not need to be inserted between the housing opening 61
and the sensor SA 50 in the height direction Y.
[0691] As Modification E8, in the first embodiment, the connection
terminal portion 172c of the connector terminal 28a may be exposed
to the connector region PC2. For example, the connection terminal
portion 172c is separated from the sealing step surface 67 toward
the housing opening 61. Even in the above configuration, if the
connection terminal portion 172c and the second terminal portion
172b do not protrude into the main body region PC1, the terminal
portions 172b and 172c can be inhibited from hindering the sensor
SA 50 from being inserted into the internal space 24a.
[0692] As Modification E9, in the first embodiment, the second
terminal portion 172b may extend not in the height direction Y but
in the width direction X or the depth direction Z.
[0693] As Modification E10, the connector region may not be
disposed between the housing opening and the unit body in the
direction in which the housing opening and the detection unit are
aligned in the internal space of the housing. For example, in the
first embodiment, the sealing step surface 67 is disposed at a
position farther from the housing opening 61 than the lead terminal
54 in the height direction Y. In the above configuration, the
connector region PC2 is aligned laterally with the sensor SA 50 in
the width direction X.
[0694] As Modification E11, if the connector terminal is fixed to
the housing, a part of the connector terminal does not necessarily
have to be embedded in the housing. For example, the connector
terminal is attached to the housing after the housing has molded
with resin with the use of a mold device. Also, in the above
configuration, if the physical quantity measurement device is
configured such that the connector terminal does not hinder the
insertion of the detection unit into the internal space of the
housing, the detection unit can be installed in the internal space
of the housing after the connector terminal has been attached to
the housing.
[0695] <Modifications of Configuration Group F>
[0696] As Modification F1, similarly to Modification E6 described
above, the detection unit installed in the internal space of the
housing may be hidden from the housing opening side by the cover
member. For example, in the first embodiment, as shown in FIG. 106,
the sensor SA 50 installed in the internal space 24a is hidden from
the housing opening 61 by the cover member 448. The cover member
448 covers the connection portion 183 in addition to the sensor SA
50. The cover member 448 has a portion that enters the internal
space 24a and a portion that overlaps with the end face of the lip
89, and the portion that enters the internal space 24a is fitted to
the inner peripheral surface 180 of the sealing region PA.
[0697] In the above configuration, both the potting portion 65 and
the cover member 448 are provided in the internal space 24a, and
the cover member 448 is disposed on the other side of the sensor SA
50 across the potting portion 65. In this case, at least one of the
potting portion 65 and the cover member 448 may seal the internal
space 24a.
[0698] At the time of manufacturing the air flow meter 14, the
cover member 448 is used as a separate member from the housing 21,
and molded with resin with the use of a molding device or the like.
After the sensor SA 50 is installed in the internal space 24a of
the housing 21 and the potting portion 65 is formed by injecting a
thermosetting resin into the internal space 24a, the cover member
448 is attached to the housing 21. In this case, the cover member
448 is fixed to the inner peripheral surface 180 of the sealing
region PA or the end face of the lip 89 with the use of an
adhesive, a molten resin, or the like.
[0699] As a configuration in which the cover member 448 covers the
sensor SA 50 from the housing opening 61, as shown in FIG. 107,
there is a configuration in which the potting portion 65 is not
provided. In the above configuration, since the internal space 24a
is not sealed by the potting portion 65, it is preferable that the
cover member 262 seals the internal space 24a.
[0700] Further, in the fourth embodiment, as in Modification E6, as
shown in FIG. 105, the sensor SA 220 installed in the internal
space 204a is covered by the cover member 449 from the housing
opening 241.
[0701] According to the above modification, the cover member 448
formed as a member different from the housing 21 is attached to the
housing 21, so that the sensor SA 50 installed in the internal
space 24a is covered and hidden by the cover member 448. When the
cover member 448 is attached to the housing 21, a pressure is
hardly applied to the internal space 24a, so that a positional
deviation of the sensor SA 50 hardly occurs. Therefore, the
detection accuracy of the flow rate detector 22 can be inhibited
from varying from product to product.
[0702] As Modification F2, the housing may have a storage groove
for storing the thermosetting resin when the thermosetting resin
overflows from the housing opening. For example, in the first
embodiment, as shown in FIG. 108, the housing 21 has a storage
groove 461 for storing the potting material 185 overflowing from
the housing opening 61. The storage groove 461 extends annularly
along a peripheral portion of the housing opening 61, and is
disposed at a position separated from the lip 89 to the outer
peripheral side on the side opposite to the sealing region PA
across the lip 89. The storage groove 461 is provided in the
housing base end face 192, which is the base end face of the
housing 21, and is opened in the height direction Y.
[0703] The housing base end face 192 is formed by an outer
peripheral surface of the housing body 24, an outer peripheral
surface of the flange portion 27, or the like, and the storage
groove 461 is provided in a portion of the housing base end face
192 formed by the outer peripheral surface of the housing body 24.
The storage groove 461 may be provided in a portion of the housing
base end face 192 formed by the outer peripheral surface of the
flange portion 27.
[0704] In the present modification, even if the potting material
185 overflows from the housing opening 61 when the potting material
185 is injected into the internal space 24a, the overflowing
potting material 185 is stored in the storage groove 461. For that
reason, the potting material 185 spreads over a wider range than
the storage groove 461, and the potting material 185 can be
inhibited from adhering to an unintended portion such as the air
flow meter 14 or the work table.
[0705] As Modification F3, the housing does not have to have an
open rib portion. For example, in the first embodiment, as shown in
FIG. 109, the lip 89 as the open rib portion does not extend from
the housing body 24, and the storage groove 461 is provided in the
outer peripheral side of the housing opening 61, similarly to
Modification F2. In the above configuration, the housing opening 61
is defined by the housing body 24 rather than the lip 89, and the
storage groove 461 is disposed in the housing base end face 192.
According to the above configuration, the potting material 185
overflowing from the housing opening 61 is stored in the storage
groove 461 in the same manner as in Modification F2 described
above.
[0706] As shown in FIG. 110, the housing 21 may not have both the
lip 89 and the storage groove 461. Also, in the above
configuration, the injection amount of the potting material 185
into the internal space 24a is adjusted so that a liquid surface or
a fluid surface of the potting material 185 does not reach the
housing opening 61, thereby being capable of inhibiting the potting
material 185 from overflowing from the housing opening 61.
[0707] As Modification F4, the inner peripheral surface of the open
rib portion and the inner peripheral surface of the housing body
may not be flush with each other, and a step may be formed between
the inner peripheral surface of the open rib portion and the inner
peripheral surface of the housing body. For example, in the first
embodiment, as shown in FIG. 111, the inner peripheral surface of
the lip 89 is disposed on the outer peripheral side of the inner
peripheral surface of the housing body 24 in the inner peripheral
surface 180 of the sealing region PA. In the above configuration,
an opening step surface 463 facing the housing opening 61 is formed
between the inner peripheral surface of the lip 89 and the inner
peripheral surface of the housing body 24. The opening step surface
463 extends annularly along the peripheral portion of the housing
opening 61 in the same manner as that of the lip 89.
[0708] According to the above configuration, when an operator
injects the potting material 185 into the internal space 24a, it is
preferable to adjust the injection amount of the potting material
185 so that the potting material 185 does not reach the opening
step surface 463. In this case, even if the potting material 185
reaches the opening step surface 463, the potting material 185 has
not yet reached the housing opening 61, and the potting material
185 can be inhibited from overflowing from the housing opening 61
beyond the lip 89.
[0709] As Modification F5, an inner peripheral recess portion
recessed in the inner peripheral surface of the housing may be
provided at the open end portion of the internal space. For
example, in the first embodiment, as shown in FIG. 112, an inner
peripheral recess portion 464 recessed in the inner peripheral
surface 180 of the sealing region PA is provided at a position
extending over the inner peripheral surface 180 and the housing
base end face 192. The inner peripheral recess portion 464 is also
open toward the housing opening 61 and extends annularly along the
peripheral portion of the housing opening 61. The inner peripheral
surface of the inner peripheral recess portion 464 forms an inner
peripheral surface 180.
[0710] According to the above configuration, when the operator
injects the potting material 185 into the internal space 24a, it is
preferable to adjust the injection amount of the potting material
185 so that the potting material 185 does not reach the inner
peripheral recess portion 464. In this case, even if the potting
material 185 reaches the inner peripheral recess portion 464, the
potting material 185 has not yet reached the housing opening 61,
and the potting material 185 can be inhibited from overflowing from
the housing opening 61 beyond the inner peripheral recess portion
464.
[0711] Further, as shown in FIG. 113, a recess inner groove 465 for
storing the potting material 185 that has entered an inside of an
inner peripheral recess portion 464 is provided in the inner
peripheral recess portion 464. The recess inner groove 465 is
formed in a surface of the inner peripheral surface of the inner
peripheral recess portion 464 facing the housing opening 61 side,
and is opened toward the housing opening 61 side. The recess inner
groove 465 extends annularly along the inner peripheral recess
portion 464.
[0712] According to the above configuration, a volume of the inner
peripheral recess portion 464 is increased by the volume of the
recess inner groove 465. For that reason, even if the potting
material 185 injected into the internal space 24a reaches the inner
peripheral recess portion 464, the injection amount of the potting
material 185 necessary until the potting material 185 reaches the
housing opening 61 is increased. Therefore, the overflow of the
potting material 185 from the housing opening 61 beyond the inner
peripheral recess portion 464 is less likely to occur by the volume
of the recess inner groove 465.
[0713] As Modification F6, a chamfered portion in which the inner
peripheral end of the housing base end face is chamfered may be
provided at the open end portion of the internal space. For
example, in the first embodiment, as shown in FIG. 121, a chamfered
portion 466 configured by chamfering an outgoing corner portion of
the housing 21 is provided so as to extend over the housing base
end face 192 and the inner peripheral surface 180. The chamfered
portion 466 is a chamfered surface obtained by chamfering an
outgoing corner portion where the housing base end face 192 and the
inner peripheral surface 180 of the sealing region PA intersect
with each other, and extends straight in the direction of gradually
expanding the sealing region PA toward the housing base end face
192 in the height direction Y. The chamfered portion 466 extends
annularly along the peripheral portion of the housing opening
61.
[0714] According to the above configuration, it is preferable to
inject the potting material 185 into the internal space 24a until
the potting material 185 reaches the chamfered portion 466 within a
range in which the potting material 185 does not overflow from the
internal space 24a. In that case, the potting material 185 easily
creeps up the chamfered portion 466, and the potting surface 193 is
expanded by the amount by which the potting material 185 creeps up
the chamfered portion 466, so that the size of the information
portion 194 to be applied to the potting surface 193 can be
increased. As a result, the visibility of the information portion
194 can be enhanced.
[0715] The chamfered portion 466 may be a curved surface. Examples
of the curved surface include a curved surface in which the
chamfered portion 466 budges toward the housing base end face 192
in the height direction Y, and a curved surface in which the
chamfered portion 466 is recessed toward the housing tip end face
191.
[0716] As Modification F7, the inner peripheral curved surface of
the inner peripheral surface of the housing does not necessarily
have to be curved as long as the inner peripheral curved surface is
bent so as to bulge toward the outer peripheral side. For example,
the inner peripheral curved surface may be bent at multiple
locations so as to bulge toward the outer peripheral side. Even in
this case, since the two inner peripheral flat surfaces
intersecting with each other are connected to each other by the
inner peripheral curved surfaces, the thermosetting resin can be
inhibited from creeping up the inner peripheral surface of the
housing when the thermosetting resin is injected into the internal
space of the housing.
[0717] As Modification F8, in the case where the filling portion
such as the potting portion 65 is formed by the filler such as the
potting material 185, the filler may be slowly cured at room
temperature, instead of forcibly curing the filling material by
applying heat.
[0718] As Modification F9, as the filler filled in the internal
space of the housing, not a thermosetting resin such as the potting
material 185 is used, but a photocurable resin cured by irradiation
of light or an ultraviolet curable resin cured by irradiation of
ultraviolet rays may be used. As the filler, an adhesive which is
hardened by exposure to air or application of water may be used. In
short, the internal space may be filled with a curable resin which
is cured by application of heat, light, air, water, or the like as
a filler. Even in this case, the filler filled in the internal
space is cured to form the filled portion. The filler is cured to
such an extent that the shape of the filler can be maintained,
thereby forming the filled portion.
[0719] <Modification of Configuration Group G>
[0720] As Modification G1, similarly to Modification F1, the
internal space of the housing may be sealed by the cover member.
For example, in the first embodiment, a cover member is molded with
a resin as a member separate from the housing 21, and the cover
member is attached to the housing 21 so as to close the internal
space 24a from the housing opening 61 side. In the above
configuration, the cover member corresponds to a sealing portion,
and the information portion 194 is provided on the outer surface of
the cover member. Also, in the above configuration, since the
housing opening 61 and the internal space 24a are increased in
size, the outer surface of the cover member is increased in size,
so that the visibility of the information portion 194 can be
enhanced.
[0721] As Modification G2, in the first embodiment, the SA main
body 170 of the sensor SA 50 and the connector terminal 28a may be
aligned in the depth direction Z. Even in this instance, when the
sensor SA 50 is inserted into the internal space 24a from the
housing opening 61, the connector terminal 28a can be inhibited
from becoming troublesome.
[0722] As Modification G3, in the first embodiment, the housing
opening 61 may not be oriented in the height direction Y, but may
be oriented in the width direction X or the depth direction Z. Even
in this instance, it is preferable that the housing opening 61 is
disposed at a position opposed to the inflow port 33a across the
sensor SA 50 and the ring holding portion 25 in the height
direction Y. In other words, it is preferable that the potting
surface 193 is disposed outside the intake pipe 12a in a state in
which the air flow meter 14 is attached to the intake pipe 12a. As
a result, the operator can visually recognize the information
portion 194 of the potting surface 193 without removing the air
flow meter 14 from the intake pipe 12a.
[0723] <Modification of Configuration Group H>
[0724] As Modification H1, in the first embodiment, the second
temperature detector 506 may not be mounted on the lead frame 82 as
long as the second temperature detector 506 is disposed between the
housing base end face 192 and the first temperature detector 505.
For example, as shown in FIG. 114, the second temperature detector
506 is mounted on the circuit chip 81. In the above configuration,
a board of the circuit chip 81 corresponds to a circuit board on
which elements of the second temperature detector 506 are mounted.
The second temperature detector 506 may be mounted on the relay
board 83, the lead terminal 54, or the like.
[0725] As Modification H2, in the first embodiment, after the
second correction signal is acquired by performing a response
correction of the second temperature signal Sa2, a difference
between the second correction signal and the first correction
signal Sb1 may be calculated. For example, as shown in FIG. 115,
the second correction unit 513 does not perform the response
correction of the temperature differential signal Sb2, but performs
the response correction of the second temperature signal Sa2.
[0726] The second correction unit 513 calculates a second
correction signal Sb11 by performing the response correction of the
second temperature signal Sa2, and outputs the second correction
signal Sb11 to the temperature differential unit 512. The second
correction unit 513 corrects the second temperature signal Sa2 with
the use of a behavior of change of the second temperature signal
Sa2 in the same manner as the first correction unit 511 corrects
the first temperature signal Sa1 with the use of the behavior of
change of the first temperature signal Sa1. The second correction
unit 513 uses the flow rate signal Sa3 and the flow rate
transformation signal sb4 to correct the second temperature signal
Sa2 in the same manner as the first correction unit 511 uses the
flow rate signal Sa3 and the flow rate transformation signal sb4 to
correct the first temperature signal Sa1.
[0727] Rather than calculating the differential correction signal
Sb3, the temperature differential unit 512 calculates a corrected
differential signal Sb12 which is a difference between the first
correction signal Sb1 and the second correction signal Sb11. The
correction amount calculation unit 515 calculates a correction
amount signal Sb5 with the use of the corrected differential signal
Sb12 and the flow rate transformation signal sb4.
[0728] Also, in the above configuration, the second temperature
signal Sa2 is used as a correction parameter for the correction of
the first temperature signal Sa1. For that reason, even if the
correction amount signal Sb5 is calculated with the use of the
corrected differential signal Sb12 instead of the differential
correction signal Sb3, the error of the correction value signal Sc
with respect to an actual temperature Sd can be reduced. Therefore,
as compared with the configuration in which the second correction
signal Sb11 is not used for the correction of the first temperature
signal Sa1, the measurement accuracy of the correction value signal
Sc can be improved.
[0729] As Modification H3, in the first embodiment, the response
correction of the temperature differential signal Sb2 may not be
performed. For example, as shown in FIG. 116, the temperature
correction unit 510 does not have the second correction unit 513.
In the above configuration, the temperature differential signal Sb2
calculated by the temperature differential unit 512 is input
directly to the correction amount calculation unit 515. Also, in
the above configuration, the second temperature signal Sa2 is used
as the correction parameter for the correction of the first
temperature signal Sa1 similarly to Modification H2 described
above. For that reason, even if the correction amount signal Sb5 is
calculated with the use of the temperature differential signal Sb2
instead of the differential correction signal Sb3, an error of the
correction value signal Sc with respect to the actual temperature
Sd can be reduced. Therefore, the measurement accuracy of the
correction value signal Sc can be enhanced in the same manner as in
Modification H2 described above.
[0730] As Modification H4, in the first embodiment, the second
temperature signal Sa2 may not be used for correcting the first
temperature signal Sa1. For example, as shown in FIG. 117, the
temperature correction unit 510 does not include the temperature
differential unit 512, the second correction unit 513, the
correction amount calculation unit 515, and the correction value
calculation unit 516. In the above configuration, the first
correction signal Sb1 output from the first correction unit 511 is
acquired as the correction value signal Sc. Also, in the above
configuration, the behavior of change of the first temperature
signal Sa1 and the flow rate signal Sa3 are used as the correction
parameters for the correction of the first temperature signal Sa1.
For that reason, even if the second temperature signal Sa2 is not
used for the correction of the first temperature signal Sa1, the
response of the correction value signal Sc to the actual
temperature Sd can be enhanced. In the present modification, the
air flow meter 14 does not need to have the second temperature
detector 506.
[0731] As Modification H5, in the first embodiment, the flow rate
signal Sa3 may not be used to correct the first temperature signal
Sa1. For example, as shown in FIG. 118, the temperature correction
unit 510 does not include the second correction unit 513, the
characteristic transformation unit 514, and the correction amount
calculation unit 515. In the above configuration, the correction
value calculation unit 516 calculates the correction value signal
Sc with the use of the second temperature signal Sa2 instead of the
correction amount signal Sb5. Also, in the above configuration, the
second temperature signal Sa2 is used for correcting the first
temperature signal Sa1 in the same manner as in Modification H2
described above. For that reason, even if the flow rate signal Sa3
is not used for the correction of the first temperature signal Sa1,
the error of the correction value signal Sc with respect to the
actual temperature Sd can be reduced. In the present modification,
the air flow meter 14 does not need to have the flow rate detector
22.
[0732] As Modification H6, in the first embodiment, the response
correction of the first temperature signal Sa1 may not be
performed. For example, as shown in FIG. 119, the temperature
correction unit 510 does not include the first correction unit 511,
the correction amount calculation unit 515, and the correction
amount calculation unit 515. In the above configuration, the
correction value calculation unit 516 calculates the correction
value signal Sc with the use of the first temperature signal Sa1
instead of the first correction signal Sb1. Also, in the above
configuration, the second temperature signal Sa2 is used for
correcting the first temperature signal Sa1 in the same manner as
in Modification H2 described above. For that reason, even if the
behavior of change of the first temperature signal Sa1 is not used
for the correction of the first temperature signal Sa1, the error
of the correction value signal Sc with respect to the actual
temperature Sd can be reduced.
[0733] As Modification H7, in the first embodiment, the correction
value calculation unit 516 may calculate the correction value
signal Sc by multiplying a signal based on the first temperature
signal Sa1 by a signal based on the second temperature signal Sa2
or the flow rate signal Sa3 instead of integrating the signals. For
example, as shown in FIG. 118, the correction value calculation
unit 516 calculates the correction value signal Sc by multiplying
the first correction signal Sb1 by the temperature differential
signal Sb2. As shown in FIG. 119, the correction value calculation
unit 516 multiplies the first temperature signal Sa1 by the
differential correction signal Sb3 to calculate the correction
value signal Sc.
[0734] As Modification H8, in the first embodiment, the first
temperature detector 505 may not be mounted on the detection board
22a of the flow rate detector 22 as long as the first temperature
detector 505 is disposed on the opposite side of the housing
opening 61 across the second temperature detector 506 in the height
direction Y. For example, the first temperature detector 505 is
mounted on the relay board 83 or the lead frame 82.
[0735] As Modification H9, in the first embodiment, at least one of
the first temperature detector 505 and the second temperature
detector 506 may not be mounted on the sensor SA 50. For example,
the first temperature detector 505 is embedded in the longitudinal
partition wall 69 of the housing 21, or the second temperature
detector 506 is mounted on the connector terminal 28a.
[0736] As Modification H10, in the first embodiment, the flow rate
detector 22 and the first temperature detector 505 may be mounted
on boards independent of each other as long as those detectors are
provided in the measurement flow channel 32. The flow rate detector
22 and the first temperature detector 505 may be disposed at
positions separated from each other in the height direction Y. Even
in this instance, since the detection targets to be detected by the
flow rate detector 22 and the first temperature detector 505 are
intake air flowing through the measurement flow channel 32, the
response of the first temperature signal Sa1 using the flow rate
signal Sa3 can be enhanced.
[0737] As Modification H11, in the first embodiment, the physical
quantity corrected based on its behavior of change is the
temperature, but the correction target may be a physical quantity
different from the temperature, such as the flow rate, humidity,
and pressure of the intake air. For example, a first pressure
detector for detecting a pressure is provided in the measurement
flow channel 32 as a physical quantity detector, and a second
pressure detector as the same kind-quantity detector for detecting
a physical quantity of the same kind as the first pressure detector
is disposed at a position closer to the housing base end face 192
than the first pressure detector. In the above configuration, in
the measurement control device, the first pressure signal which is
the detection result of the first pressure detector is corrected
with the use of the second pressure signal which is the detection
result of the second pressure detector.
[0738] In addition, the physical quantity measurement device has a
temperature detector that detects a temperature as the different
kind-quantity detector that detects a physical quantity of a kind
different from the pressure, and in the measurement control device,
the first pressure signal is corrected with the use of a
temperature signal that is a detection result of the temperature
detector. Further, in the measurement control device, the first
pressure signal is corrected with the use of the behavior of change
of the first pressure signal. According to those configurations,
the accuracy of pressure measurement and the response of pressure
measurement can be enhanced with respect to the measurement of
pressure as a physical quantity.
[0739] As Modification H12, in the first embodiment, the
measurement control device for correcting the first temperature
signal Sa1 may be configured not by the circuit chip 81 but by
another control device included in the air flow meter 14. In
addition, the measurement control device may be provided in an
external device such as an ECU 20 in addition to the air flow meter
14. For example, the first temperature signal Sa1, the second
temperature signal Sa2, and the flow rate signal Sa3 are input to
the ECU 20 from the first temperature detector 505, the second
temperature detector 506, and the flow rate detector 202 through
the circuit chip 81, respectively. Further, the measurement control
device may be various arithmetic devices mounted on a vehicle, and
multiple arithmetic devices may function as a control device in
cooperation with each other. In addition, various programs may be
stored in a non-transitory tangible storage medium such as a flash
memory or a hard disk provided in each calculation device.
[0740] While the present disclosure has been described with
reference to embodiments thereof, it is to be understood that the
disclosure is not limited to the embodiments and constructions. To
the contrary, the present disclosure is intended to cover various
modification and equivalent arrangements. In addition, while the
various elements are shown in various combinations and
configurations, which are exemplary, other combinations and
configurations, including more, less or only a single element, are
also within the spirit and scope of the present disclosure.
* * * * *