U.S. patent application number 11/117508 was filed with the patent office on 2005-09-08 for sensor mounting structure and semiconductor pressure sensor for motor vehicles.
This patent application is currently assigned to HITACHI, LTD. Invention is credited to Matsumura, Takafumi, Miyazaki, Atsushi, Tanaka, Hiroyuki, Yamaguchi, Shinichi.
Application Number | 20050193809 11/117508 |
Document ID | / |
Family ID | 17855217 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050193809 |
Kind Code |
A1 |
Matsumura, Takafumi ; et
al. |
September 8, 2005 |
Sensor mounting structure and semiconductor pressure sensor for
motor vehicles
Abstract
To provide a sensor mounting structure which enables mounting an
automotive sensor directly to the wall section of a part to be
detected, without using screws, and also mounting a pressure
detector directly to a pressure air passage without using a
pressure inlet pipe. The non-circular sensor mounting hole is
provided for inserting a part of the sensor housing into the wall
section of the part to be detected. In the sensor housing the first
locking portion (pawl) and the second locking portion (flange) are
integrally formed by molding. The housing 1 is allowed to be
inserted into the mounting hole under the condition that the pawl
is directed to a specific orientation, and, after insertion, is
turned through a specific angle. Therefore the pawl is engaged on
the inside surface of the wall section. The flange is engaged on
the outside surface of the wall section. The pawl and the flange
are designed to hold the wall section of the part to be detected,
thereby mounting the sensor. The projection of the hook is engaged
with the recess provided in the sensor housing 1, thus locking the
sensor from turning.
Inventors: |
Matsumura, Takafumi;
(Hitachinaka-shi, JP) ; Miyazaki, Atsushi;
(Mito-shi, JP) ; Yamaguchi, Shinichi;
(Hitachinaka-shi, JP) ; Tanaka, Hiroyuki;
(Hitachinaka-shi, JP) |
Correspondence
Address: |
CROWELL & MORING LLP
INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
HITACHI, LTD
Tokyo
JP
|
Family ID: |
17855217 |
Appl. No.: |
11/117508 |
Filed: |
April 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11117508 |
Apr 29, 2005 |
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10942819 |
Sep 17, 2004 |
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10942819 |
Sep 17, 2004 |
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10214757 |
Aug 9, 2002 |
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6845656 |
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10214757 |
Aug 9, 2002 |
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09421268 |
Oct 20, 1999 |
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6470739 |
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Current U.S.
Class: |
73/114.38 |
Current CPC
Class: |
G01L 19/0007 20130101;
G01L 19/003 20130101 |
Class at
Publication: |
073/118.2 |
International
Class: |
G01P 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 1998 |
JP |
10-298104 |
Claims
What is claimed is:
1. A sensor mounting structure for motor vehicles, wherein: a
pressure sensor is attached directly to an intake manifold through
a mounting hole provided in a pipe wall of said intake manifold of
an internal-combustion engine; a pressure inlet port of said
pressure sensor is open directly in said intake air pipe; a
pressure sensitive gauge is mounted in said pressure inlet port;
and said pressure inlet port of said pressure sensor is attached
approximately horizontally and in this state said gauge is mounted
in an upper position inside said pressure inlet port.
2. A sensor mounting structure for motor vehicles according to
claim 1, wherein a face for mounting said gauge looks down.
3. A sensor mounting structure for motor vehicles according to
claim 1, wherein said pressure inlet port is provided with a down
inclination toward said intake manifold.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a sensor mounting structure
for mounting an automotive sensor (e.g., a pressure sensor, a
temperature sensor, etc.) and a semiconductor pressure sensor to be
used.
[0002] There have been used various kinds of sensors for
electronically controlling an internal-combustion engine mounted in
a motor vehicle. These conventional sensors were attached by
screws. For instance, as disclosed in Japanese Unexamined Patent
Publication No. Hei 5-172673, brackets are attached in two places
on a plastic molding housing to provide the pressure sensor
mounting position with a degree of freedom of movement. The
pressure sensor is attached by screws in an appropriate position
through the bracket and the sensor section and a pressure source
are connected by means of a hose.
[0003] In recent years, a metal intake air passage, or a so-called
intake manifold made of a metal, for use in the internal-combustion
engine in motor vehicles is giving way to an intake manifold of
synthetic resin. In the case of the synthetic resin manifold, it
becomes necessary to form, by insert-molding, a metal part for
receiving a mounting screw to fix a sensor housing at the time of
molding the intake manifold, resulting in an increased cost.
[0004] It is also necessary to insert a metal bushing on the
housing side to prevent biting and loosening of the screw, which
also increases the cost.
[0005] To facilitate the mounting of the sensor, therefore, there
has been proposed a method of dispensing with a bracket and a hose
for introducing the pressure from the pressure source, and fixing
the sensor directly on the pipe wall of the intake air passage in
place of using the screw.
[0006] For instance, according to Japanese Unexamined Patent
Publication No. Sho 63-215847, a cylindrical section larger in
diameter than the sensor body is employed as the sensor mounting
section. On the sensor side is provided a locking flange section of
a non-circular contour; and an insertion hole is formed in the
cylindrical section to insert the sensor. The insertion hole has a
locking hole for inserting the locking flange portion of the sensor
at a specific angle in the inlet side and, after insertion, the
locking flange section is allowed to turn. The locking flange
section of the sensor is locked by a spring force on the inside
surface of the locking hole to thereby mount the sensor.
[0007] This method, however, requires insertion of a spring member
beside the sensor body into the sensor mounting section
(cylindrical section), which will increase both cost and labor for
assembling.
[0008] In Japanese Unexamined Patent Publication No. Sho 63-215846,
disclosed is the sensor mounting structure that a cylindrical
portion is provided as a sensor mounting section which is larger
than the sensor body; on either one of the cylindrical portion and
the sensor, there is provided an elastic locking leg which is
elastically deformable in the radial direction of the cylindrical
portion; on the other, a fixed locking portion is provided to lock
and lock the sensor from turning in engagement with the elastic
locking leg in a free state; and the elastic locking leg is pressed
into contact with the fixed locking portion by the force of a disk
spring, to thereby prevent accidental removal of the sensor. In
this case also, it becomes necessary to form a cylindrical portion
as the sensor mounting section, and to insert a spring member
beside the sensor body into the sensor mounting section
(cylindrical portion), resulting in an increased cost and labor for
assembling.
[0009] In Japanese Unexamined Patent Publication No. Hei 10-122914
there has been proposed a sensor mounting structure in which an
elastic member (e.g., a rubber member) having a front end flange
and a rear end flange is attached on the projecting portion of a
sensor; the elastic member together with the projecting portion of
the sensor is inserted, with the rear end flange left non-inserted,
into a through hole provided in a member to be attached. After
insertion, the front end flange is locked on the inside surface of
the member to be attached, while the rear end flange is locked on
the outside surface of the member to be attached. The example given
above requires an elastic member for mounting the sensor, which
increases the number of component parts, and furthermore requires a
process for mounting the elastic member to the projecting portion
of the sensor prior to mounting the sensor.
[0010] It is, therefore, an object of the present invention first
to provide a sensor mounting structure for motor vehicles which
facilitates mounting the sensor to the wall of the intake manifold
while dispensing with screwing of the sensor, and further to
decrease the number of component parts and to simplify the
structure as compared with a conventional mounting structure system
which needs no screws.
[0011] It is another object to provide a semiconductor pressure
sensor capable of directly mounting an intake air pressure sensor
which is one of automotive sensors, to the wall of the intake
manifold, and installing the pressure detecting gauge of the sensor
into the intake passage while dispensing with a pressure inlet
pipe.
[0012] It is further another object to provide a sensor mounting
structure capable of preventing water formed by condensation from
icing in the pressure detecting section to maintain reliability of
the pressure detecting section when the semiconductor pressure
sensor is mounted directly on the wall of the intake manifold,
particularly when the semiconductor pressure sensor is mounted with
the pressure inlet port in a horizontal or nearly horizontal
position.
BRIEF SUMMARY OF THE INVENTION
[0013] To accomplish the above-described objects, the sensor
mounting structure for motor vehicles of the present invention has
basically the following configuration.
[0014] According to the first invention, in the sensor mounting
structure for motor vehicles for mounting, on a wall section of a
part to be detected, a sensor for detecting a physical value
necessary for operating a motor vehicle, characterized in that said
sensor is mounted by: providing a sensor mounting hole of
non-circular contour for inserting a part of said sensor into said
wall section of said part to be detected; and forming in a housing
of said sensor, integrally with said housing by molding, first
locking portion allowed said sensor to insert into said mounting
hole in a specific orientation and engaged on the wall surface
which faces the inside of the part to be detected by turning
through a specific angle after insertion, and second locking
portion engaged on the wall surface which faces the outside of the
part to be detected; and holding said wall section of said part to
be detected between said first and second locking portions.
[0015] According to the above-described configuration, when the
sensor is attached on the wall section of a part to be detected,
the first locking portion provided on the sensor housing is
directed to a specific orientation, aligning both the first locking
portion and the mounting holes made in the wall section of the part
to detected. In this state, the sensor housing is inserted into the
mounting holes thus aligned (until the first locking portion passes
through the outlet of the mounting hole, or, in other words, until
the second locking portion contacts the wall surface which faces
the outside of the part to be detected). Thereafter, as the sensor
housing is turned through a specific angle, the first locking
portion is engaged on the wall surface which faces the inside of
the part to be detected, while the second locking portion is
engaged on the wall surface which faces the outside of the part to
be detected. The first and second locking portions hold the wall
section of the part to be detected, thus directly mounting the
sensor on the wall section of the part to be detected, without
using the screw.
[0016] According to the second invention, a housing making up a
sensor body is formed to be attached on the wall section of the
part to be detected, with a gauge portion thereof disposed directly
on the part to be detected, and is of a two-piece structure which
includes a sensor holder having a pressure detecting semiconductor
gauge housing section, a housing section for holding a circuit
substrate mounted with an electronic circuitry and a connector, and
a cylindrical cap in which the sensor holder is inserted, with the
connector mounted outside; and a pressure inlet port is formed by
the shape of semiconductor gauge housing section of the sensor
holder and the cap.
[0017] According to the above-described configuration, the sensor
body (sensor housing) is formed simply by inserting the sensor
holder having an electronic circuit section and a semiconductor
gauge into the cap with the connector portion left outside, and the
semiconductor gauge (pressure detector) housing section is located
in the pressure inlet port, thereby enabling direct detection of a
pressure without a pressure inlet pipe. Besides, the semiconductor
gauge, if disposed directly into the part to be detected (e.g., the
intake manifold), is protected by the cap positioned around the
gauge, to thereby insure reliability of the pressure sensor.
[0018] In the sensor mounting structure for motor vehicles
according to the third invention, the pressure sensor is attached
directly on the intake manifold of the internal-combustion engine
through the mounting hole provided in the pipe wall of the intake
manifold; and the pressure inlet port of the sensor opens directly
into the intake manifold. A gauge which responds to the pressure is
mounted in this pressure inlet port.
[0019] In this sensor mounting structure, the pressure inlet port
of the pressure sensor is mounted horizontally or nearly
horizontally; in this mounting state, the gauge is disposed in the
upper part of the inside of the pressure inlet port.
[0020] In the configuration in which the pressure sensor is mounted
directly on the pipe wall of the intake manifold with the pressure
detector (gauge portion) exposed into the intake manifold, the
pressure sensor has such a drawback that if the pressure inlet port
is located horizontally or nearly horizontally, water generated as
a result of sweating in the intake manifold enters the pressure
inlet port and freezes to give damage to the gauge. However, when
the gauge is disposed in the upper part of the pressure inlet port
as stated in the above-described configuration, water caused by
sweating will not enter the gauge. It is, therefore, possible to
protect the gauge from damage resulting from icing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is an explanatory view showing, in section, a
mounting hole provided in the intake manifold of an internal
combustion engine for motor vehicles;
[0022] FIG. 2 is a bottom view of FIG. 1;
[0023] FIG. 3 is an explanatory view showing the sensor in the
course of mounting;
[0024] FIG. 4 is a bottom view of FIG. 3;
[0025] FIG. 5 is a longitudinal sectional view of the semiconductor
pressure sensor for use in the aforesaid embodiment;
[0026] FIG. 6 is a top view of the mounting hole for fixing the
pressure sensor;
[0027] FIG. 7 is a top view of the sensor mounting structure of the
present embodiment;
[0028] FIG. 8 is a longitudinal sectional view showing an example
of mounting the intake manifold installed at an angle different
from that in FIG. 1;
[0029] FIG. 9 is an explanatory view showing the sensor mounting
state of another embodiment of the present invention; and
[0030] FIG. 10 is an explanatory view showing the sensor mounting
state of another embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0031] Preferred embodiments of the present invention will be
explained with reference to the accompanying drawings of a
semiconductor pressure sensor for one example.
[0032] FIG. 1 is an explanatory view showing one embodiment of the
sensor mounting structure according to the present invention,
partly sectioned at the mounting hole made in an intake manifold of
an internal-combustion engine for motor vehicles; FIG. 2 is a
bottom vied thereof; FIG. 3 is an explanatory view showing the
sensor on the way of mounting; FIG. 4 is a bottom view thereof;
FIG. 5 is a longitudinal sectional view of the semiconductor
pressure sensor; and FIG. 6 is a top view of the mounting hole in
which the pressure sensor is fixed.
[0033] First, referring to FIGS. 1, 3 and 5, the structure of the
overall housing which is the body of the semiconductor pressure
sensor will be explained. The whole body of the housing 1 is
separated largely into two parts as shown in FIG. 5; one is a
sensor holder 1A including a connector 10, while the other is a
cylindrical cap 1B containing the sensor holder 1A inserted
therein. The sensor holder 1A and the cap 1B are both produced
through a synthetic resin molding process.
[0034] The sensor holder 1A is a base called a molded case for
mounting and holding a chip 13 including the semiconductor gauge
for pressure detection and such an electronic circuit as an
amplifier circuit, and a circuit substrate 14 to be prepared and
mounted outside when needed.
[0035] On one side of this sensor holder 1A there are formed a
pocket 11 for housing the semiconductor gauge and the chip
(pressure detector) 13 of the amplifier circuit, and a pocket 12
for housing a circuit substrate 14. The chip 13 is attached in the
pocket 11, while the circuit substrate 1, in the pocket 12.
[0036] The chip 13 making up the semiconductor gauge is a
millimeter-order microchip for use as a capacitance type sensor
formed by for instance surface micromachining, details of which are
not shown on the drawing. The principle of the surface
micromachining is that the chip 13 is comprised of a first
electrode (fixed electrode) formed of a film of aluminum spatter on
a single-crystal silicon substrate (on one side) and a
diaphragm-type second electrode (movable electrode) formed of an
electrically conductive polycrystal silicon and located oppositely
to the first electrode over a gap. With the displacement of the
second electrode by a pressure, the electric capacitance varies to
thereby detect the pressure.
[0037] Since the semiconductor gauge can be formed of such a
microchip (also termed a semiconductor gauge or a pressure
detector) 13, which is directly mounted on, and partly inserted
into, the intake manifold of an engine by means of the sensor
housing structure and the sensor mounting structure described
later, it is possible to detect the pressure by the chip 13.
[0038] The sensor holder 1A includes the pocket 11, pocket 12 and
connector 10, which are arranged in order of mention as viewed from
the connector 10 side at the rear. Between the pocket 11 and the
pocket 12 a partition wall (a plate-like projection) 18 is formed
integrally with the sensor holder 1A to separate these pockets from
each other.
[0039] The cap 1B is a cylindrical type, in which an axial through
space is provided to insert the sensor holder 1A therein. On the
inside wall of the through space there are provided step portions
30, 31 and 32 to engage with the sensor holder 1A. A locking
portion 19 which engages with the step portion 32 is flange-shaped
and disposed between the connector 10 of the sensor holder 1A and
the pocket 12. In the cap 1B, there is formed a receiving portion
(step portion) 33 for receiving a partition wall 18 when the sensor
holder 1A is inserted. The sensor holder 1A, when inserted into the
cap 1B, is bonded to the cap 1B. At this time, the partition wall
18 also is bonded to the receiving portion 33 of the cap 1B,
thereby separating the pocket 11 from the pocket 12 while keeping
airtightness.
[0040] A pressure inlet portion 17 is formed by the shape of the
pocket (semiconductor gauge housing section) 11 and the forward end
of the cap 1B.
[0041] The pockets 11 and 12 of the sensor holder 1A are filled
with gel for protection of the pressure detector (chip) 13 and the
circuit substrate 14. The gel in the pocket 11 is phlorosilicone
gel which has excellent resistance to chemicals such as water
generated in the intake manifold, gasoline, and acid, and is
charged into the pocket 11 by injection.
[0042] On the other hand, filled in the pocket 0.12 is a dimethyl
silicone gel for protection of the circuit substrate 14. The
circuit substrate 14, not appearing into the pressure inlet port
17, is not affected by water, gasoline, and acid, and therefore it
is unnecessary to take the chemical resistance into consideration.
The pockets 11 and 12 may be disposed either on the same surface or
on a different surface; and furthermore it is unnecessary to
separate the pocket 12 from the pocket 11 by the partition wall if
only the pressure detector and the circuit substrate are protected
with the phlorosilicone gel having a high chemical resistance.
[0043] The chip 13 used as the pressure detector, external circuit
substrate 14, and connector 10, are electrically connected by
bonding a lead wire 15 between terminals of lead frames thereof. At
the pressure detector 13, the amount of deflection of the gauge
which moves in response to the intake manifold pressure is changed
into an electric signal, which is amplified by an amplifier
circuit, and then can be take out as a sensor output from a
terminal 16 of the connector 10.
[0044] Next, an explanation will be given of the sensor mounting
structure for mounting the pressure sensor to the pipe wall (wall
section) 6 of the intake manifold (a part to be detected).
[0045] As shown in FIGS. 1 to 6, mounting holes 60 for mounting the
pressure sensor are formed in the pipe wall 6 of the intake
manifold. The mounting holes 60 include a round hole 60A for
receiving the cylindrical barrel portion of the sensor housing 1
and a hole 60B for receiving the forward end of the sensor housing
1 to thereby lead the lock pawl 4 on the forward end of the sensor
housing 1 into the round recess 61 in the inside wall of the intake
manifold 6.
[0046] The hole 60B is a non-circular sensor mounting hole
comprising a central portion 60B-1 which fits on the outside
diameter of the forward end of the sensor housing 1 and a lock pawl
insertion hole 60B-2 extended outwardly from the central part at a
spacing of 180 degrees. Hereinafter the hole 60B, being of a
keyhole type, will be called a keyhole. On the peripheral edge of
the hole 60A of the intake manifold (wall section) 6, two engaging
hooks (elastic members) 8 are arranged at a 180-degree spacing.
There is formed a groove 9 which allows outward elastic deformation
of the hooks 8. Inside the hooks 8, tapered projections 7 are
formed to fit in recesses 3 formed in the barrel portion of the
sensor housing 1. The recesses 3 are arranged at a spacing of 180
degrees. It should be noticed that the number and arrangement of
the hooks 8 and the recesses 3 are not limited thereto. On the
barrel portion of the sensor housing 1 an O-ring 5 is attached to
keep airtightness when the sensor housing 1 is inserted into the
mounting hole 60. The O-ring 5 is fitted in an annular groove 50
formed in the outer periphery of the sensor housing 1.
[0047] The lock pawl 4 stated above functions as the first locking
portion, which, when positioned in a specific orientation, can be
inserted into the keyhole 60B of the mounting hole 60 and, after
insertion, is turned through a specific angle to be engaged with
the inside surface (a surface facing inside) of the wall section 6
of the intake manifold. That is, the lock pawl 4 is engaged with
the inside surface of the wall section 6 of the intake manifold to
lock the sensor housing 1 from moving out after the sensor housing
1 is turned through the specific angle (e.g., 90 degrees). To
ensure this operation, the hole 60B has a configuration of a
keyhole.
[0048] On the barrel portion of the sensor housing 1, the second
locking portion 2 is formed of a flange to lock the sensor on the
outside surface (a surface facing outside) of the wall section 6 of
the intake manifold when the sensor is inserted as deep as the
mounting position in the mounting hole 60.
[0049] Next, a method of mounting the sensor of the present example
will be explained with reference to FIGS. 1 to 4.
[0050] First, as shown in FIGS. 3 and 4, the sensor housing 1 is
inserted and positioned in a specific orientation so that the first
locking portion (lock pawl) 4 may be inserted into the keyhole 60B.
At this time, the recess 3 provided in the sensor housing 1 is
positioned 90 degrees off the hook 8 arranged in the mounting hole
60. The barrel portion of the sensor housing 1 in which position
the recess 3 is formed is larger in diameter than the spacing
between the projections 7, 7 of the pair of hooks 8 disposed at a
spacing of 180 degrees. Furthermore, since the projection 7 is
tapered, the hook 8 is pushed to open outwardly as indicated by the
arrow b by the elasticity of the hook caused when the sensor
housing 1 is pushed in.
[0051] Next, as shown in FIGS. 1 and 2, when the sensor housing 1
is turned through a specific angle (90 degrees in this case), the
recess 3 fits on the projection 7 of the hook 8; and the hook 8, as
indicated by the arrow a in FIG. 1, is moved back to the original
position by the spring characteristics, thereby locking the sensor
housing 1. When the sensor housing 1 is turned 90 degrees, the lock
pawl 4 turns together with the sensor housing 1 in the recess 61
formed in the inside wall of the intake manifold.
[0052] In this state, the lock pawl (first locking portion) of the
sensor housing 1 and the flange (second locking portion) 2 hold the
intake manifold wall 6, to thereby restrict the axial movement of
the sensor.
[0053] If, in such a state of mounting, there is not adopted such a
fixing system that the first and second locking portions (lock pawl
4 and the flange 2) are pressed by the spring force particularly
against the intake manifold (wall section 6), a pull caused by a
negative pressure built up in the intake manifold works to the
sensor housing 1 when the internal-combustion engine is operated;
and therefore the flange 2 is pressed against the outside surface
of the intake manifold, thus securely fixing the sensor without
looseness. Also, when a pull acts on the sensor (housing 1) because
a positive pressure is present in the passage or because a harness
connected to the connector 10 is pulled, the lock pawl 4 located
inside works as a stopper to prevent accidental removal of the
sensor. In case a force is applied in the direction of rotation
because of vibration from the internal-combustion engine, first the
vibration in the direction of rotation is absorbed by the O-ring 5,
and therefore the force working on the sensor housing 1 is
decreased and furthermore the housing 1 which is fixedly locked
from turning will not turn.
[0054] When the sensor housing 1 is fixed in the mounting hole 60,
a space between the sensor housing 1 and the mounting hole 60 is
sealed by the O-ring 5, thus enabling to provide airtightness of
the intake manifold. In this case, other than the O-ring may be
attached to the cap 1B; for instance, a bellows-shaped rubber is
inserted or attached on the cap 1B, the rubber is pressed against
the inside surface of the mounting hole 60, thus enabling to
provide the airtightness.
[0055] When the projection 7 of the hook 8 is fitted in the recess
3, a stress is not constantly added to the hook 8, and therefore
there will never occur such a problem as creep and relaxation of
stress of the hook 8 having a spring characteristic.
[0056] The sensor, when needed to be removed from the intake
manifold, can be pulled off by turning the sensor housing 1 in the
reverse direction of mounting to disengage the projection 7 of the
hook 8 from the recess 3 until the sensor housing 1 comes in the
position shown in FIGS. 3 and 4.
[0057] In this case, as shown in FIG. 7 (a top view of the sensor
mounting structure of the present invention), it is advised to
provide a peep window 21 in the flange 2 of the sensor housing 1
for peeping the fitting section where the projection 7 of the hook
8 fits in the recess 3 formed in the housing 1 side; and through
this peep window 21, a jig for spreading the hook 8 is inserted to
turn the housing 1 a little to remove the projection 7 from the
recess 3. Then, after removing the jig, the housing 1 can easily be
turned to pull out to the position before insertion.
[0058] In the above-described example, the sensor explained is the
intake manifold pressure sensor. However, it is to be noted that
the sensor is not limited thereto and may be an intake air
temperature sensor, a cooling water temperature sensor to be used
in other than the intake manifold, and various other kinds of
sensors to be mounted on the exhaust manifold.
[0059] According to the present embodiment, the present invention
has the following advantages.
[0060] (1) Since the sensor for motor vehicles can be attached
without using a screw, the number of component parts for attaching
the sensor can be reduced; particularly when the intake manifold or
other is produced of a synthetic resin, it is possible to easily
and at a low cost install the sensor to the intake manifold or
other produced of the synthetic resin.
[0061] (2) Since the pressure sensor is attached on the intake
manifold and the semiconductor gauge for pressure detection is
exposed directly into the intake manifold, no pressure inlet pipe
is needed. Besides, if a circuit substrate such as an electronic
circuit is mounted in the sensor housing, entry of water and
gasoline can be prevented, thereby enabling to provide sensor
reliability.
[0062] FIG. 8 gives an example of the pressure sensor of the
present embodiment mounted on the intake manifold at an angle
different from FIG. 1.
[0063] The pressure sensor housing 1 is attached with the pressure
inlet port 17 positioned horizontally or nearly horizontally. In
this mounting state, the gauge (chip 13) which serves as the
pressure detector is placed in the upper part of the interior of
the pressure inlet port 17.
[0064] Within the intake manifold, water vapor is sometimes
condensed. When the sensor housing 1 is mounted vertically as shown
in FIG. 1, the pressure inlet port 17 faces down to allow smooth
discharge of water.
[0065] Actually, however, the sensor housing 1 is in some cases
required to be mounted horizontally or nearly horizontally. In this
case, the pressure inlet port 17 is positioned horizontally or
nearly horizontally, causing water resulting from sweating to enter
the pressure inlet port 17. If the water enters, and freezes in,
the gauge (chip 13) which is the pressure detector, the pressure
detector is liable to breakdown. According to the present
embodiment, in the pressure detecting gauge 13 arranged in the
upper part in the pressure inlet port 17, water will run down if
present in the pressure inlet port 17. Furthermore, as shown in
FIG. 8, the interior of the pressure inlet port 17 is provided with
an inclination 17=to allow smooth discharge of water into the
intake manifold (intake air passage), thus enabling to prevent
giving damage of icing to the gauge.
[0066] FIG. 9 shows another embodiment of the present invention,
which differs from the embodiments in FIGS. 1 to 8 in the respect
that the hook 8 with the projection 7 and the groove 9 are provided
on the sensor housing 1 side, and the recess 3 is formed in the
mounting hole 60 side. According to this configuration also, it is
possible to lock the sensor housing similarly to the aforesaid
embodiment.
[0067] FIG. 10 also shows another embodiment of the present
invention, in which the flange 2 is dispensed with, and in place of
the flange 2 a part 101 of the barrel portion of the cap 1B of the
sensor housing 1 is engaged with a stepped surface 62 facing
outwardly in a mounting hole 60. The part 101 of the cap 1B and the
lock pawl 4 are designed to hold the intake manifold wall surface
around the keyhole 60B.
[0068] According to the present invention, as heretofore described,
the automotive sensor can easily be installed to the intake
manifold wall or other without using screws. Besides, it is
possible to realize the sensor mounting structure which can reduce
a component count and simplify the structure as compared with a
conventional mounting structure system which dispenses with
screws.
[0069] Furthermore, it is possible to provide a semiconductor
pressure sensor which directly attaches the intake air pressure
sensor which is one of automotive sensors, to the intake manifold
wall, and moreover to expose into the intake air passage the
pressure detecting gauge of the sensor which can dispense with the
pressure inlet pipe.
[0070] Furthermore, when the semiconductor pressure sensor is
attached directly to the intake manifold wall, particularly when
the semiconductor pressure sensor is attached with the pressure
inlet port set horizontally or nearly horizontally, it is possible
to prevent water caused by condensation from icing on the
semiconductor gauge, thus preventing impairing the pressure
detector.
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