U.S. patent application number 12/262839 was filed with the patent office on 2009-05-21 for oil strainer for transmission.
This patent application is currently assigned to HONDA MOTOR CO., LTD.. Invention is credited to Isamu SHINBORI, Susumu TAKEI, Yasuyuki Takei, Yoshimichi TSUBATA.
Application Number | 20090127174 12/262839 |
Document ID | / |
Family ID | 38667624 |
Filed Date | 2009-05-21 |
United States Patent
Application |
20090127174 |
Kind Code |
A1 |
SHINBORI; Isamu ; et
al. |
May 21, 2009 |
OIL STRAINER FOR TRANSMISSION
Abstract
An oil strainer for a transmission including a resin-made upper
case which is formed in a side surface of an upper part of a
communication port for communication with a pump and which has an
upper flange along the outer periphery thereof, a resin-made lower
case which is provided with an oil suction port in a lower surface
thereof and which has a lower flange joined to the upper flange of
the upper case, and a filter member which is disposed in a space
formed by joining the upper and lower cases and which filters an
oil flowing from the oil suction port to the communication port.
The oil strainer is configured to further includes an oil suction
port cover member which is so formed as to cover at least an inside
upper surface of the oil suction port and which forms a passage for
conducting the oil to the filter member.
Inventors: |
SHINBORI; Isamu; (Wako,
JP) ; TSUBATA; Yoshimichi; (Wako, JP) ; TAKEI;
Susumu; (Wako, JP) ; Takei; Yasuyuki;
(Sakado-shi, JP) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW, SUITE 700
WASHINGTON
DC
20036
US
|
Assignee: |
HONDA MOTOR CO., LTD.
Tokyo
JP
|
Family ID: |
38667624 |
Appl. No.: |
12/262839 |
Filed: |
October 31, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2007/057235 |
Mar 30, 2007 |
|
|
|
12262839 |
|
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Current U.S.
Class: |
210/167.08 |
Current CPC
Class: |
F16H 57/0404 20130101;
F16H 57/0443 20130101; B01D 35/0273 20130101; F16H 57/0452
20130101 |
Class at
Publication: |
210/167.08 |
International
Class: |
F01M 11/03 20060101
F01M011/03 |
Foreign Application Data
Date |
Code |
Application Number |
May 1, 2006 |
JP |
2006-127584 |
Claims
1. An oil strainer for a transmission, comprising: a resin-made
upper case which is provided with a communication port for
communication to a pump in a side surface of an upper part thereof
and which has an upper flange at an outer periphery thereof; a
resin-made lower case which is provided with an oil suction port in
a lower surface thereof and which has a lower flange joined to said
upper flange of said upper case; a filter member which is disposed
in a space formed by joining said upper and lower cases and which
filters an oil flowing from said oil suction port to said
communication port; and an oil suction port cover member which is
so formed as to cover at least an inside upper surface of said oil
suction port and which forms a passage for conducting said oil to
said filter member.
2. The oil strainer for a transmission as set forth in claim 1,
wherein said oil suction port cover member is so formed as to cover
the left and right sides and the rear side of said oil suction port
or the left and right sides and the front side of said oil suction
port, as viewed along the forward vehicle running direction.
3. The oil strainer for a transmission as set forth in claim 2,
wherein both an end position of said oil suction port in the
direction for conducting said oil by said oil suction port cover
member and the total amount of said oil in said transmission are so
determined that said end position of said oil suction port is
located substantially at the intersection between an oil surface at
the time of a maximum vehicle acceleration and an oil surface at
the time of a maximum vehicle deceleration.
4. The oil strainer for a transmission as set forth in claim 3,
wherein said oil suction port cover member is opened in the forward
vehicle running direction, a tip position of said oil suction port
cover member in said oil conducting direction is located as if
advanced more in said forward vehicle running direction than said
oil surface at the time of said maximum vehicle deceleration, and
said tip position of said oil suction port cover member is so set
as to be immersed in said oil at the time of said maximum vehicle
deceleration.
5. The oil strainer for a transmission as set forth in claim 3,
wherein said oil suction port cover member is opened in a direction
opposite to said forward vehicle running direction, a tip position
of said oil suction port cover member in said oil conducting
direction is located as if advanced more in said direction opposite
to said forward vehicle running direction than said oil surface at
the time of said maximum vehicle acceleration, and said tip
position of said oil suction port cover member is so set as to be
immersed in said oil at the time of said maximum vehicle
acceleration.
Description
[0001] This is a continuation of International PCT Application NO.
PCT/JP2007/057235, filed Mar. 30, 2007, which was not published in
English.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an oil strainer for
filtering an oil in a transmission case.
[0004] 2. Description of the Related Art
[0005] An oil used as a working fluid or a lubricating oil in a
transmission is reserved in a lower part of a transmission casing,
is sucked by an oil pump and is supplied to a control valve and
other parts to be lubricated. In this case, it is a common practice
to disposed an oil strainer in the lower part of the transmission
casing and to filter the oil through the strainer before the oil is
sucked by the pump. A configuration in which a filter member formed
from a non-woven fabric or the like is disposed in a resin-made
case to form the oil strainer has been known. In this case, the
filter member composed of the non-woven fabric is clamped between
an upper-lower pair of cases configured dividedly, and the upper
and lower cases are joined to each other, to fabricate the
strainer.
[0006] Japanese Patent Laid-open No. 2001-124188 discloses an oil
strainer wherein upper and lower cases can be vibration welded
efficiently and, in use of the oil strainer, bubbles are prevented
from stagnating at the lower surface of a lower flange. In the oil
strainer disclosed in the patent document, at the time of joining
the upper case and the lower case of the oil strainer by vibration
welding, a notch is provided in a rib formed along the whole flange
circumference of the joint part for holding a jig for vibration
welding, and air tending to stagnate at the lower part of the
flange is discharged through the notch, thereby preventing aeration
from occurring. In addition, Japanese Patent Laid-open No.
2005-291408 discloses an oil strainer wherein a filter member of an
oil strainer and a flange part of a case thereof are disposed in
the state of being inclined to the left or the right as viewed in
the forward vehicle running direction, so as to lessen the portion
where air tends to stagnate, thereby restraining the generation of
aeration.
[0007] In the oil strainer disclosed in Japanese Patent Laid-open
No. 2001-124188, complete removal of the rib formed along the whole
circumference of the flange constituting the joint part between the
upper case and the lower case is difficult in view of vibration
welding of the cases, so that the site for forming the notch is
restricted. Therefore, there remains the problem of, for example,
stagnation of air at the four corners of the oil strainer, and fine
aeration possibly caused by the stagnating air. If the oil strainer
is mounted in the state of being inclined to the front or rear side
as viewed in the forward vehicle running direction in order to
prevent the generation of the microscopic aeration, the area of the
passage in the vicinity of the oil suction port would be varied
between the time of forward running and the time of rearward
running of the vehicle. Therefore, it is difficult to secure an
aeration balance in each cases of forward running and rearward
running. In addition, in view of the structure in which a main oil
passage to the oil suction port of the strainer is along the
forward vehicle running direction, the system in which the strainer
is inclined along the front-rear direction leaves some air
stagnation area in the oil passage, again causing the fine
aeration.
[0008] In the oil strainer described in Japanese Patent Laid-open
No. 2005-291408, in consideration of the time of a change in the
oil surface such as the time of sudden vehicle start, both ends in
the vehicle running direction of the oil suction port formed in the
lower case of the oil strainer constitute dominant factors in
setting the oil surface in the transmission. Accordingly, aeration
balance is kept by making appropriate the position and dimensions
of the oil suction port. The total amount of the oil in the
transmission is substantially determined by the position and
dimensions of the oil suction port which are so set as to keep the
aeration balance. Therefore, when the total amount of the oil in
the transmission is large, the weight thereof is also large
accordingly, and there is a fear of generation of aeration due to
an increase in oil agitation resistance of gears or a fear of
worsening of fuel economy attendant on an increase in friction.
[0009] If the spacing in the vehicle running direction of the oil
suction port formed in the lower case of the oil strainer is
narrowed as a countermeasure against the problem mentioned just
above, the resistance at the time of sucking the oil would be
increased, so that the hydraulic oil in a hydraulic pressure
control circuit may be lowered, or the increase in the oil suction
resistance may cause an increase in the oil pump driving torque,
leading to worsening of fuel economy. Besides, if the oil suction
port is enlarged, aeration toughness at the time of a change in the
oil surface would be lowered, so that the total amount of the oil
in the transmission must be increased further; thus, a vicious
circle is likely to arise.
SUMMARY OF THE INVENTION
[0010] Accordingly, it is an object of the present invention to
provide an oil strainer for a transmission which is simple in
structure and with which it is possible to reduce the total amount
of oil and to restrain aeration from being generated.
[0011] In accordance with an aspect of the present invention, there
is provided an oil strainer for a transmission, including a
resin-made upper case which is provided with a communication port
for communication to a pump in a side surface of an upper part
thereof and which has an upper flange at an outer periphery
thereof, a resin-made lower case which is provided with an oil
suction port in a lower surface thereof and which has a lower
flange joined to the upper flange of the upper case, and a filter
member which is disposed in a space formed by joining the upper and
lower cases and which filters an oil flowing from the oil suction
port to the communication port, the oil strainer further including
an oil suction port cover member which is so formed as to cover at
least an inside upper surface of the oil suction port and which
forms a passage for conducting the oil to the filter member.
[0012] According to this configuration, the end position of the oil
suction port in the oil conducting direction constitutes a dominant
factor in setting the oil surface at the time of a change in the
oil surface. Therefore, it is possible to reduce the total amount
of the oil in the transmission, and to enhance aeration toughness
at the times of changes in the oil surface which are generated at
the times of acceleration and deceleration of the vehicle.
[0013] Preferably, the oil suction port cover member is so formed
as to cover the left and right sides and the rear side of the oil
suction port or the left and right sides and the front side of the
oil suction port, as viewed along the forward vehicle running
direction. This ensures that the oil flowing in through the oil
suction port can be efficiently conducted to the filter member.
Preferably, both an end position of the oil suction port in the
direction for conducting the oil by the oil suction port cover
member and the total amount of the oil in the transmission are so
determined that the end position of the oil suction port is located
substantially at the intersection between an oil surface at the
time of a maximum vehicle acceleration and an oil surface at the
time of a maximum vehicle deceleration.
[0014] When the total amount of the oil in the transmission is
determined so that the end position of the oil suction port is
located substantially at the intersection between the oil surface
at the time of a maximum vehicle acceleration and an oil surface at
the time of a maximum vehicle deceleration to lower the oil surface
as much as possible, it is possible to reduce the total amount of
the oil in the transmission, to realize a reduction in weight, and
to restrain aeration through a reduction in the oil agitation
resistance of gears. Consequently, an improvement in fuel economy
can be expected through a reduction of friction.
[0015] Further, preferably, the oil suction port cover member is
opened in the forward vehicle running direction, a tip position of
the oil suction port cover member in the oil conducting direction
is located as if advanced more in the forward vehicle running
direction than the oil surface at the time of the maximum vehicle
deceleration, and the tip position of the oil suction port cover
member is so set as to be immersed in the oil at the time of the
maximum vehicle deceleration.
[0016] Further, preferably, the oil suction port cover member is
opened in a direction opposite to the forward vehicle running
direction, a tip position of the oil suction port cover member in
the oil conducting direction is located as if advanced more in the
direction opposite to the forward vehicle running direction than
the oil surface at the time of the maximum vehicle acceleration,
and the tip position of the oil suction port cover member is so set
as to be immersed in the oil at the time of the maximum vehicle
acceleration.
[0017] According to the configuration as above-mentioned, it is
possible to restrain the generation of aeration and to efficiently
conduct the oil to the filter member, while minimizing the total
amount of the oil required for the transmission.
[0018] The above and other objects, features and advantages of the
present invention and the manner of realizing them will become more
apparent, and the invention itself will best be understood from a
study of the following description and appended claims with
reference to the attached drawings showing some preferred
embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a sectional view showing the relation between an
oil strainer and an oil surface in an embodiment of the present
invention, at the time of a standstill of the vehicle and at the
time of a maximum acceleration;
[0020] FIG. 2 is a sectional view showing the relation between the
oil strainer and the oil surface in the embodiment of the present
invention, at the time of a standstill of the vehicle and at the
time of a maximum deceleration;
[0021] FIG. 3 is a perspective view of a lower case;
[0022] FIG. 4A is a plan view of the lower case;
[0023] FIG. 4B is a sectional view taken along line 4B-4B of FIG.
4A;
[0024] FIG. 4C is a sectional view taken along line 4C-4C of FIG.
4A;
[0025] FIG. 5 shows the relation between the oil surface, an end
position of an oil suction port and an oil suction port cover
member, at the time of a maximum vehicle acceleration;
[0026] FIG. 6 shows the relation between the oil surface, the end
position of the oil suction port and the oil suction port cover
member, at the time of a maximum vehicle deceleration;
[0027] FIG. 7 shows the relation between the oil surface and the
end position of the oil suction port, at the time of the maximum
vehicle acceleration and at the time of the maximum vehicle
deceleration;
[0028] FIG. 8 is a partial longitudinal sectional view of an
automatic transmission equipped with an oil strainer according to
the embodiment of the present invention; and
[0029] FIG. 9 is a partial longitudinal sectional view of an
automatic transmission equipped with an oil strainer according to
another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Now, an oil strainer for a transmission according to an
embodiment of the present invention will be described in detail
below, referring to the drawings. Referring to FIG. 1, a schematic
sectional view of the oil strainer according to one embodiment of
the present invention is shown, together with changes of an oil
surface at the time of standstill of the vehicle and at the time of
an acceleration of the vehicle.
[0031] Reference numeral 2 denotes a bottom surface of a
transmission case, and the oil strainer 4 is disposed in the
transmission case. The oil strainer 4 includes an upper case 6
provided with a communication port 8 for communication with an oil
pump in a side surface of an upper part thereof, a lower case 12
which is provided with an oil suction port 14 in its lower surface
and which is joined to the upper case 6, and a filter member 20
which is disposed in a space 18 formed by joining the upper and
lower cases 6 and 12 and which is provided for filtering an oil
flowing from the oil suction port 14 to the communication port 8.
Both the upper case 6 and the lower case 12 are formed by resin
molding. The upper case 6 is provided with an upper flange 10 along
the outer periphery thereof, and the lower case 12 is provided with
a lower flange 16 along the outer periphery thereof.
[0032] The oil strainer 4 is produced by a method in which both the
flanges 10 and 16 are clamped by a jig or jigs of a vibration
welder so that the lower surface of the upper flange 10 and the
upper surface of the lower flange 16 are in contact with each
other, and a vibration is applied to the jig(s) of the vibration
welder, whereby both the flanges 10 and 16 are integrally welded to
each other. At the time of thus joining the resin-made upper and
lower cases 6 and 12 to each other by vibration welding, the filter
member 20 formed by use of a non-woven fabric is clamped between
both the cases 6 and 12 being joined. As a result, the filter
member 20 is so disposed as to partition the space 18 formed by
joining the upper and lower cases 6 and 12 into an upper portion
and a lower portion, and the oil flowing from the oil suction port
14 to the communication port 8 is filtered by the filter member 20.
Reference numeral 22 denotes an oil suction port cover member, by
which the oil sucked in through the oil suction port 14 is
conducted to the filter member 20. Broken line arrow 24 indicates
the flow of the oil. The oil suction port cover member 22 is formed
as shown in FIGS. 3 and 4.
[0033] FIG. 3 shows a perspective view of the lower case 12, and
FIG. 4A shows a plan view of the lower case 12. FIG. 4B is a
sectional view taken along line 4B-4B of FIG. 4A, and FIG. 4C is a
sectional view taken along line 4C-4C of FIG. 4A. As best shown in
FIGS. 4B and 4C, the oil suction port cover member 22 is formed by
integrally connecting an upper wall 22a and left and right walls
22b, 22c, and a aperture part 23 is opened in the forward vehicle
running direction. The oil suction port cover member 22 is
integrally molded at the time of molding the lower case 12 from a
resin mold.
[0034] Referring to FIG. 1 again, reference numeral 14a denotes an
end position of the oil suction port 14 in the direction in which
the oil is conducted by the oil suction port cover member 22.
Reference numeral 26 denotes an oil surface at the time of
standstill of the vehicle, whereas reference numeral 28 denotes an
oil surface at the time of a maximum acceleration of the vehicle.
In addition, reference numeral 26a denotes an oil surface at the
time of standstill of the vehicle in the case where an oil strainer
according to the related art is used, whereas reference numeral 28a
denotes an oil surface at the time of a maximum acceleration of the
vehicle in that case.
[0035] At the time of a maximum vehicle acceleration, the oil
surface is changed from the standstill oil surface 26 as indicated
by arrow 30. In addition, according to the oil strainer 4 in the
embodiment of the present invention, the total amount of oil in the
transmission required can be reduced as compared with that in the
related art; therefore, the oil surface at the time of vehicle
standstill is lowered as indicated by arrow 27, and the oil surface
at the time of a maximum vehicle acceleration is changed as
indicated by arrow 29.
[0036] FIG. 2 is a sectional view of the oil strainer, showing the
change of the oil surface at the time of a maximum vehicle
deceleration in comparison with the oil surface in the oil strainer
according to the related art. While the oil surface 26 at the time
of vehicle standstill is the same as in FIG. 1, the oil surface is
changed from the standstill oil surface 26 as indicated by arrow 34
at the time of a maximum vehicle deceleration, whereon the oil
surface is as denoted by reference numeral 32. Reference numeral
32a denotes an oil surface at the time of a maximum deceleration in
the case where an oil strainer according to the related art is
used. According to this embodiment, the oil surface 32 at the time
of the maximum deceleration is changed as indicated by arrow 33
from the oil surface 32a in the related art.
[0037] Now, referring to FIGS. 5 to 7, a preferable shape and
preferable dimensions of the oil suction port cover member 22 of
the oil strainer 4 according to the embodiment of the present
invention will be described below. FIG. 5 shows an oil surface at
the time of a maximum vehicle acceleration, FIG. 6 shows an oil
surface at the time of a maximum vehicle deceleration, and FIG. 7
shows the oil surfaces at the times of the maximum vehicle
acceleration and the maximum vehicle deceleration. As shown in
FIGS. 5 and 6, let the maximum vehicle acceleration be Gmax and let
the gravitational acceleration be g, then tan .alpha.=Gmax/g, and,
therefore, the maximum inclination angle .alpha. of the oil surface
can be expressed as .alpha.=tan.sup.-1 (Gmax/g). The maximum
deceleration can be expressed as -Gmax. The height h of the oil
suction port cover member 22 is determined taking into account the
aeration toughness based on the positional relationship between the
lower case 12 of the oil strainer 4 and the filter member 20, while
securing a passage area of not less than the area of the oil
suction port 14.
[0038] In addition, as shown in FIG. 7, both the end position 14a
of the oil suction port 14 in the direction in which the oil is
conducted by the oil suction port cover member 22 and the total
amount of oil in the transmission are determined so that the end
position 14a of the oil suction port 14 is located substantially at
the intersection between the oil surface 28 at the time of the
maximum vehicle acceleration and the oil surface 32 at the time of
the maximum vehicle deceleration. Thus, in this embodiment, the oil
surface can be determined by the end position 14a of the oil
suction port 14 in the oil conducting direction. Therefore, the
height of the oil surface can be set lower than that in the related
art, the total amount of oil in the transmission can be reduced,
and aeration toughness at the times of variations in the oil
surface which are generated at the times of vehicle acceleration
and deceleration can be enhanced.
[0039] Besides, the tip position 22d in the oil conducting
direction of the oil suction port cover member 22 is located as if
advanced more in the forward vehicle running direction than the oil
surface 32 at the time of the maximum vehicle deceleration, and the
tip position 22d of the oil suction port cover member 22 is so set
as to be immersed in the oil at the time of the maximum vehicle
deceleration. In other words, the length 1 of the oil suction port
cover member 22 shown in FIGS. 5 to 7 is so set that the tip
position 22d of the oil suction port cover member 22 is immersed in
the oil at the time of the maximum vehicle deceleration.
[0040] Referring to FIG. 8, there is shown a partial longitudinal
sectional view of an automatic transmission equipped with the oil
strainer 4 according to the embodiment of the present invention.
The communication port 8 of the oil strainer 4 is connected to an
oil pump 46. The oil pump 46 is connected to a crankshaft 44 of an
engine (not shown) through a case 42 of a torque converter 40, and
is normally driven by the engine. A gear 48 is non-rotatably fixed
to a main shaft 38 of the automatic transmission, and gears 50 and
52 are rotatably mounted on the main shaft 38. With a wet-type
multiple-disk clutch 54 engaged, the gear 50 is fixed relative to
the main shaft 38. With a wet-type multiple-disk clutch 56 engaged,
the gear 52 is fixed relative to the main shaft 38.
[0041] FIG. 9 is a partial longitudinal sectional view of an
automatic transmission equipped with an oil strainer 60 according
to another embodiment which has an oil suction port cover member
22' characteristic of the present invention. The oil strainer 60 is
disposed in the state of being inclined to the right or left side
with reference to the forward vehicle running direction. An oil
suction port 62 of the oil strainer 60 is covered with the oil
suction port cover member 22', which is the same as that in the
above-described embodiment, and a communication port 64
communicates with an oil pump 46. According to this embodiment, a
lower part of the case of the transmission can be reduced according
to the shape of the oil strainer 60, so that a further reduction in
the total amount of oil in the transmission can be expected, as
compared with the above-described embodiment.
[0042] According to the above-described embodiment of the present
invention, both the end position 14a of the oil suction port 14 in
the direction in which the oil is conducted by the oil suction port
cover member 22 and the total amount of oil in the transmission can
be so determined that the end position 14a of the oil suction port
14 is located substantially at the intersection between the oil
surface 28 at the time of a maximum vehicle acceleration and the
oil surface 32 at the time of a maximum vehicle deceleration. This
makes it possible to lower, as much as possible, the height of the
oil surface, and to reduce the total amount of oil in the
transmission. Further, it is possible to enhance the aeration
toughness at the times of changes in the oil surface which are
generated at the times of vehicle acceleration and deceleration, to
restrain aeration through a reduction in oil weight and a reduction
in oil agitation resistance of gears, and to promise an improvement
in fuel economy attendant on a reduction of friction.
[0043] Incidentally, while an example in which the aperture of the
oil suction port cover member 22 is opened toward the front side of
the vehicle has been described in the embodiment described above,
the aperture of the oil suction port cover member 22 may be set to
face toward the rear side of the vehicle. In this case, the tip
position in the oil conducting direction of the oil suction port
cover member is located as if advanced more in the direction
(toward the rear side of the vehicle) opposite to the forward
vehicle running direction than the oil surface at the time of a
maximum vehicle acceleration, and the tip position of the oil
suction port cover member is so set as to be immersed in the oil at
the time of the maximum vehicle acceleration.
* * * * *