U.S. patent application number 15/262553 was filed with the patent office on 2017-03-16 for vehicle hydraulic device.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is AISIN AW CO., LTD., TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Takafumi INAGAKI, Yoshihiro MIZUNO, Shuji MORIYAMA, Hiromitsu NITANI, Yoshinobu SOGA, Mitsuhiro TAKEDA.
Application Number | 20170074263 15/262553 |
Document ID | / |
Family ID | 58160908 |
Filed Date | 2017-03-16 |
United States Patent
Application |
20170074263 |
Kind Code |
A1 |
MIZUNO; Yoshihiro ; et
al. |
March 16, 2017 |
VEHICLE HYDRAULIC DEVICE
Abstract
A check valve provided makes it possible to operate a vane pump
smoothly even at the start of the vane pump by maintaining an oil
pressure in backpressure oil passages inside the vane pump while
the vane pump is stopped. The check valve opens at the point in
time when an oil pressure control device, to which a working fluid
is supplied from the vane pump, has been filled with the working
fluid and the oil pressure in discharge oil passages communicating
with the oil pressure control device has risen and exceeded the oil
pressure in the backpressure oil passages. Thus, the check valve is
prevented from opening and closing repeatedly, so that the
durability of the check valve is improved.
Inventors: |
MIZUNO; Yoshihiro;
(Nagoya-shi, JP) ; MORIYAMA; Shuji; (Nagakute-shi,
JP) ; SOGA; Yoshinobu; (Toyota-shi, JP) ;
INAGAKI; Takafumi; (Toyota-shi, JP) ; NITANI;
Hiromitsu; (Nagakute-shi, JP) ; TAKEDA;
Mitsuhiro; (Anjo-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA
AISIN AW CO., LTD. |
Toyota-shi
Anjo-shi |
|
JP
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
AISIN AW CO., LTD.
Anjo-shi
JP
|
Family ID: |
58160908 |
Appl. No.: |
15/262553 |
Filed: |
September 12, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 15/064 20130101;
F04C 2270/701 20130101; F04C 2/3446 20130101; F01C 21/0863
20130101 |
International
Class: |
F04C 14/24 20060101
F04C014/24; F04C 15/00 20060101 F04C015/00; F04C 15/06 20060101
F04C015/06; F04C 2/344 20060101 F04C002/344 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 14, 2015 |
JP |
2015-181241 |
Claims
1. A vehicle hydraulic device comprising: a vane pump that is
driven to rotate by an engine, the vane pump including a pump
housing, a plurality of vanes, and a rotor, the pump housing having
an inner peripheral cam surface with an elliptical sectional shape,
the plurality of vanes being provided inside the pump housing, the
rotor providing vane housing grooves that house the plurality of
vanes so as to be movable in a radial direction of the rotor; and
an oil pressure control circuit including backpressure oil passages
and discharge oil passages, the backpressure oil passages being
configured to supply a backpressure to the plurality of vanes
inside the vane housing grooves, the discharge oil passages being
configured to: (i) introduce a working fluid discharged from the
vane pump, and (ii) supply the working fluid to a device other than
the vehicle hydraulic device, a check valve provided between the
backpressure oil passages and the discharge oil passages, the check
valve being configured to: (i) open when an oil pressure of the
working fluid in the discharge oil passages discharged from the
vane pump is higher than the oil pressure in the backpressure oil
passages, and (ii) block a flow of the working fluid when the oil
pressure of the working fluid in the discharge oil passages
discharged from the vane pump is equal to or lower than the oil
pressure in the backpressure oil passages.
2. A vehicle hydraulic device comprising: a vane pump that is
driven to rotate by an engine, the vane pump including a pump
housing, a plurality of vanes, a rotor, and check valves, the pump
housing having an inner peripheral cam surface with an elliptical
sectional shape, the plurality of vanes being provided inside the
pump housing, the rotor providing vane housing grooves that house
the plurality of vanes so as to be movable in a radial direction of
the rotor, the check valves being configured to open to allow a
flow of a working fluid and close to shut off the flow of the
working fluid; and an oil pressure control circuit including
backpressure oil passages and discharge oil passages, the
backpressure oil passages being configured to supply a backpressure
to the plurality of vanes inside the vane housing grooves, the
discharge oil passages being configured to: (i) introduce the
working fluid discharged from the vane pump, and (ii) supply the
working fluid to a device other than the vehicle hydraulic device,
wherein the check valves are interposed between the backpressure
oil passages and the discharge oil passages, and the check valves
are configured to: (i) open when an oil pressure of the working
fluid in the discharge oil passages discharged from the vane pump
is higher than the oil pressure in the backpressure oil passages,
and (ii) block the flow of the working fluid when the oil pressure
of the working fluid in the discharge oil passages discharged from
the vane pump is equal to or lower than the oil pressure in the
backpressure oil passages.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Japanese Patent
Application No. 2015-181241 filed on Sep. 14, 2015, the entire
contents of which are hereby incorporated by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to a vehicle hydraulic device
having a vane pump as the oil pressure source, and more
particularly to a technique for enhancing the durability of a valve
that applies a backpressure to vanes.
[0004] 2. Description of Related Art
[0005] A vane pump driven by an engine has, inside a pump housing
with a substantially elliptical inner peripheral cam surface, for
example, a plurality of variable-displacement pump chambers that
are defined by a rotor fitted on a rotating shaft and a plurality
of vanes radially fitted into vane housing groves formed in the
rotor. As the vanes rotate while being pressed against the inner
peripheral surface of the pump housing, the volumes of the pump
chambers vary and a discharge force is applied to a working
fluid.
[0006] The force for pressing the vanes against the inner
peripheral surface of the pump housing is derived from a rotational
centrifugal force and a backpressure that presses the vanes against
the inner peripheral surface of the pump housing inside the rotor,
and the working fluid discharged from the vane pump is used to
obtain this backpressure. However, if the rotation speed of the
rotor is low at the start of the vane pump, even when the
centrifugal force of the rotating vanes and the backpressure
generated by the working fluid discharged from the vane pump are
combined, the force that presses the vanes against the inner
peripheral surface of the pump housing may be too small for the
pump to start smoothly.
[0007] To address this problem, Japanese Patent Application
Publication No. 10-196557 discloses a technique for preventing the
backpressure inside a vane pump from decreasing while the vane pump
is stopped. Specifically, in this vane pump, vane housing grooves
provided inside the rotor and a discharge oil passage that supplies
a working fluid discharged from the vane pump to an oil pressure
control device communicate with each other through a backpressure
oil passage. A check valve that opens only when the pressure on the
vane pump side is equal to or higher than a predetermined value is
provided on the downstream side from the communication point, i.e.,
on the side of an oil pressure control circuit that receives and
consumes a supply of oil pressure from the vane pump. Thus, the
proposed vane pump operates smoothly even at the start.
[0008] In the vane pump of JP 10-196557 A, when the pressure of the
working fluid discharged from the vane pump to the valve becomes
equal to or higher than the predetermined value, the check valve
provided in the discharge oil passage extending from the vane pump
to the oil pressure control circuit shifts from a closed state to
an open state. However, the check valve is closed again when the
oil pressure is lowered by the opening of the valve. Thus, the
durability of the check valve may decline as the check valve opens
and closes repeatedly.
SUMMARY
[0009] Having been devised in the context of the above situation,
the present disclosure provides a vehicle hydraulic device
including a vane pump, in which a check valve is provided to allow
the vane pump to operate smoothly even at the start and the
durability of the check valve is improved.
[0010] According to one aspect of the present disclosure, a vehicle
hydraulic device including a vane pump, an oil pressure control
circuit and a check valve is provided. The vane pump is driven to
rotate by an engine. The vane pump includes a pump housing, a
plurality of vanes, and a rotor. The pump housing has an inner
peripheral cam surface with an elliptical sectional shape. The
plurality of vanes are provided inside the pump housing. The rotor
provides vane housing grooves that house the plurality of vanes so
as to be movable in a radial direction of the rotor. The oil
pressure control circuit has a backpressure oil passage and a
discharge oil passage. The backpressure oil passage is configured
to supply a backpressure to the plurality of vanes inside the vane
housing grooves. The discharge oil passage is configured to: (i)
introduce a working fluid discharged from the vane pump, and (ii)
supply the working fluid to a device other than the vehicle
hydraulic device. The check valve is provided between the
backpressure oil passage and the discharge oil passage. The check
valve is configured to: (i) open when the oil pressure of the
working fluid in the discharge oil passage discharged from the vane
pump is higher than the oil pressure in the backpressure oil
passage, and (ii) block the flow of the working fluid when the oil
pressure of the working fluid in the discharge oil passage
discharged from the vane pump is equal to or lower than the oil
pressure in the backpressure oil passage.
[0011] According to another aspect of the present disclosure, a
vehicle hydraulic device including a vane pump and an oil pressure
control circuit is provided. The vane pump is driven to rotate by
an engine. The vane pump includes a pump housing, a plurality of
vanes, a rotor, and a check valve. The pump housing has an inner
peripheral cam surface with an elliptical sectional shape. The
plurality of vanes are provided inside the pump housing. The rotor
provides vane housing grooves that house the plurality of vanes so
as to be movable in a radial direction of the rotor. The check
valve is configured to open to allow the flow of a working fluid
and close to shut off the flow of the working fluid. The oil
pressure control circuit has a backpressure oil passage, a
discharge oil passage, and a check valve. The backpressure oil
passage is configured to supply a backpressure to the plurality of
vanes inside the vane housing grooves. The discharge oil passage is
configured to introduce the working fluid discharged from the vane
pump and supply the working fluid to a device other than the
vehicle hydraulic device through the discharge oil passage. The
check valve is interposed between the backpressure oil passage and
the discharge oil passage. The check valve is configured to: (i)
open when the oil pressure of the working fluid in the discharge
oil passage discharged from the vane pump is higher than the oil
pressure in the backpressure oil passage, and (ii) block the flow
of the working fluid when the oil pressure of the working fluid in
the discharge oil passage discharged from the vane pump is equal to
or lower than the oil pressure in the backpressure oil passage.
[0012] If such a configuration is adopted, the check valve opens at
the point in time when the oil pressure control circuit, to which
the working fluid is supplied from the vane pump, has been filled
with the working fluid and the oil pressure in the discharge oil
passage communicating with the oil pressure control circuit has
risen and exceeded the oil pressure in the backpressure oil
passage. Thus, the check valve is prevented from opening and
closing repeatedly, so that the durability of the check valve is
improved.
SUMMARY
[0013] Having been devised in the context of the above situation,
the present disclosure provides a vehicle hydraulic device
including a vane pump, in which a check valve is provided to allow
the vane pump to operate smoothly even at the start and the
durability of the check valve is improved.
[0014] According to one aspect of the present disclosure, a vehicle
hydraulic device including a vane pump and an oil pressure control
circuit, the vehicle hydraulic device further including a check
valve, is provided. The vane pump is driven to rotate by an engine.
The vane pump includes a pump housing, a plurality of vanes, and a
rotor. The pump housing has an inner peripheral cam surface with an
elliptical sectional shape. The plurality of vanes are provided
inside the pump housing. The rotor provides vane housing grooves
that house the plurality of vanes so as to be movable in a radial
direction of the rotor. The oil pressure control circuit has a
backpressure oil passage and a discharge oil passage. The
backpressure oil passage is configured to supply a backpressure to
the plurality of vanes inside the vane housing grooves. The
discharge oil passage is configured to: (i) introduce a working
fluid discharged from the vane pump, and (ii) supply the working
fluid to a device other than the vehicle hydraulic device. The
check valve is provided between the backpressure oil passage and
the discharge oil passage. The check valve is configured to: (i)
open when the oil pressure of the working fluid in the discharge
oil passage discharged from the vane pump is higher than the oil
pressure in the backpressure oil passage, and (ii) block the flow
of the working fluid when the oil pressure of the working fluid in
the discharge oil passage discharged from the vane pump is equal to
or lower than the oil pressure in the backpressure oil passage.
[0015] According to another aspect of the present disclosure, a
vehicle hydraulic device including a vane pump and an oil pressure
control circuit is provided. The vane pump is driven to rotate by
an engine. The vane pump includes a pump housing, a plurality of
vanes, a rotor, and a check valve. The pump housing has an inner
peripheral cam surface with an elliptical sectional shape. The
plurality of vanes are provided inside the pump housing. The rotor
provides vane housing grooves that house the plurality of vanes so
as to be movable in a radial direction of the rotor. The check
valve is configured to open to allow the flow of a working fluid
and close to shut off the flow of the working fluid. The oil
pressure control circuit has a backpressure oil passage, a
discharge oil passage, and a check valve. The backpressure oil
passage is configured to supply a backpressure to the plurality of
vanes inside the vane housing grooves. The discharge oil passage is
configured to: (i) introduce the working fluid discharged from the
vane pump, and (ii) supply the working fluid to a device other than
the vehicle hydraulic device through the discharge oil passage. The
check valve is interposed between the backpressure oil passage and
the discharge oil passage. The check valve is configured to: (i)
open when the oil pressure of the working fluid in the discharge
oil passage discharged from the vane pump is higher than the oil
pressure in the backpressure oil passage, and (ii) block the flow
of the working fluid when the oil pressure of the working fluid in
the discharge oil passage discharged from the vane pump is equal to
or lower than the oil pressure in the backpressure oil passage.
[0016] If such a configuration is adopted, the check valve opens at
the point in time when the oil pressure control circuit, to which
the working fluid is supplied from the vane pump, has been filled
with the working fluid and the oil pressure in the discharge oil
passage communicating with the oil pressure control circuit has
risen and exceeded the oil pressure in the backpressure oil
passage. Thus, the check valve is prevented from opening and
closing repeatedly, so that the durability of the check valve is
improved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Features, advantages, and technical and industrial
significance of exemplary embodiments will be described below with
reference to the accompanying drawings, in which like numerals
denote like elements, and wherein:
[0018] FIG. 1 is a schematic view illustrating the configuration of
the major part of a vehicle hydraulic device of a first
embodiment;
[0019] FIG. 2 is a front view of a vane pump of the vehicle
hydraulic device of FIG. 1, with a cover thereof removed;
[0020] FIG. 3 is a sectional view of the major part inside a recess
of a vane pump of a second embodiment;
[0021] FIG. 4 is a front view of a cover of FIG. 3;
[0022] FIG. 5 is a front view of a first side plate of FIG. 3;
[0023] FIG. 6 is a rear view of the first side plate of FIG. 3;
[0024] FIG. 7 is a front view of a second side plate of FIG. 3;
[0025] FIG. 8 is a rear view of the second side plate of FIG.
3;
[0026] FIG. 9 is a rear view of a third side plate of FIG. 3;
[0027] FIG. 10 is a front view of a body of FIG. 3;
[0028] FIG. 11 is a sectional view of the major part of the second
embodiment showing the second side plate, in which a first check
valve is incorporated, the third side plate, and the body;
[0029] FIG. 12A is a front view of a retainer, constituting a part
of the first check valve of FIG. 11, as seen from the side of the
body;
[0030] FIG. 12B is a front view of a leaf spring, constituting a
part of the first check valve of FIG. 11, as seen from the side of
the body; and
[0031] FIG. 12C is a front view of a sheet, constituting a part of
the first check valve of FIG. 11, as seen from the side of the
body.
DETAILED DESCRIPTION OF EMBODIMENTS
[0032] In the following, a first embodiment of a vehicle hydraulic
device will be described in detail with reference to the
drawings.
[0033] FIG. 1 is a schematic view illustrating the configuration of
the vehicle hydraulic device. A vehicle hydraulic device 10
includes a check valve 90, and a vane pump 14 that supplies a
working fluid to an oil pressure control device 12 functioning as
an oil pressure control circuit that consumes the working fluid,
such as the hydraulic cylinder of the sheave etc. of an automatic
transmission (A/T) or a continuously variable transmission
(CVT).
[0034] The vane pump 14 is driven by the rotation of an engine 15.
The vane pump 14 has a first suction port 22 and a second suction
port 24 through which the working fluid stored in an oil pan 18 is
suctioned via an oil strainer 20, and a first discharge port 26 and
a second discharge port 28 through which the suctioned working
fluid is discharged to the outside of the pump. The vane pump 14
further has a first backpressure groove 62 and a second
backpressure groove 64 that supply a backpressure to a plurality of
vanes 81 that suction and discharge the working fluid. The working
fluid is sent from the suction ports 22, 24 to the discharge ports
26, 28 through pump chambers P formed by the vanes 81.
[0035] A first discharge oil passage 30 and a second discharge oil
passage 31, each functioning as the discharge oil passage, are
connected to the first discharge port 26 and the second discharge
port 28, respectively. The first discharge oil passage 30 and the
second discharge oil passage 31 are further connected to a
discharge oil passage 29, and serve as working fluid supply
passages to the oil pressure control device 12 through which the
working fluid discharged from the first discharge port 26 and the
second discharge port 28 is pumped to the oil pressure control
device 12.
[0036] A first backpressure oil passage 35 and a second
backpressure oil passage 36, each corresponding to the backpressure
oil passage, are connected to the first backpressure groove 62 and
the second backpressure groove 64, respectively. A check valve 90
is provided between the first and second discharge oil passages 30,
31 and the first and second backpressure oil passages 35, 36.
[0037] A suction oil passage 34 connects the first and second
suction ports 22, 24 of the vane pump 14 and the oil pan 18 to each
other via the oil strainer 20 such that the working fluid stored in
the oil pan 18 is suctioned into the first suction port 22 and the
second suction port 24. A return oil passage 32 returns the working
fluid of the oil pressure control device 12 to the suction oil
passage 34 of the vane pump 14.
[0038] FIG. 2 is a front view showing the vane pump 14 of the
vehicle hydraulic device 10 with a pump cover removed. The vane
pump 14 is composed of: a body 44 having a substantially columnar
recess 16 formed therein; a substantially cylindrical cam ring 70,
corresponding to a pump housing, that is fitted inside the recess
16 so as to be unable to rotate relative to the body 44; a
disc-shaped side plate 37 that is mounted so as to be interposed
between a bottom wall surface of the recess 16 of the body 44 and
the cam ring 70, with one flat surface and the other flat surface
of the side plate 37 respectively in contact with the bottom wall
surface of the recess 16 and a substantially circular one end
surface of the cam ring 70; a columnar rotor 74 housed such that
the outer peripheral surface faces an inner peripheral cam surface
78 of the cam ring 70 with a small space therebetween, and that one
end surface in the direction of a rotational axis can come into
sliding contact with the other flat surface of the side plate 37; a
pump shaft 76 that is fixed to the rotor 74 coaxially with the
rotational axis of the rotor 74 and rotatably supported on the body
44, and rotates the rotor 74 in the direction of the arrow
indicated in FIG. 2, i.e., in the clockwise direction, according to
the driving of a driving source, such as the engine 15; and the
pump cover (not shown) that is fastened to the body 44 so as to be
in contact with the substantially circular other end surface of the
cam ring 70 and cover the opening of the recess 16 while being able
to come into sliding contact with the other end surface of the
rotor 74 in the axial direction.
[0039] The cam ring 70 has the inner peripheral cam surface 78 that
is the inner peripheral surface with a substantially elliptical
sectional shape. The rotor 74 includes a plurality of slits 80,
corresponding to the vane housing grooves, that are formed over the
entire axial length of the outer peripheral surface, radially from
a center part in the radial direction toward the outer peripheral
surface at regular intervals in the circumferential direction, and
the plurality of rectangular, plate-shaped vanes 81 that are fitted
into the slits 80. Since the slits 80 house the vanes, the slits 80
are also called vane housing grooves. The vane 81 is inserted into
the slit 80 such that the side surfaces of the vane 81 in the
circumferential direction of the rotor 74 can slide in the radial
direction of the rotor 74 over an inner wall of the slit 80 facing
the vane 81; that the side surfaces in the axial direction come
into sliding contact with the other end surface of the side plate
37 and an inner wall surface of the pump cover, respectively; and
that the radially outer end surface of the vane 81 can slide over
the inner peripheral cam surface 78 of the cam ring 70.
[0040] When the rotor 74 is driven to rotate, the vane 81 is pushed
out toward the radially outer side of the rotor 74 from the inner
wall of the slit 80 under the backpressure from the first
backpressure groove 62 and the second backpressure groove 64, so
that the radially outer end surface of the vane 81 is pressed
against the inner peripheral cam surface 78 of the cam ring 70 and,
in this state, slides over the inner peripheral cam surface 78 in
the rotation direction of the rotor 74. Thus, the plurality of pump
chambers P are defined by the side surfaces of the adjacent vanes
81 facing each other in the circumferential direction, the inner
peripheral cam surface 78, the outer peripheral surface of the
rotor 74, the other end surface of the side plate 37, and the inner
wall surface of the pump cover. Since the inner peripheral cam
surface 78 has a substantially elliptical shape, as the rotor 74
makes one rotation, the vane 81 reciprocates twice inside the slit
80 in the radial direction of the rotor 74, so that the volume of
the pump chamber P increases and decreases twice.
[0041] In the side plate 37 and the body 44, the pair of first
suction port 22 and second suction port 24 communicating with the
pump chambers P, which increase in volume according to the rotation
of the rotor 74, are formed across the pump shaft 76 so as to
straddle both the side plate 37 and the body 44. In the side plate
37 and the body 44, the pair of first discharge port 26 and second
discharge port 28 communicating with the pump chambers P, which
decrease in volume according to the rotation of the rotor 74, are
formed across the pump shaft 76 so as to straddle both the side
plate 37 and the body 44. The first discharge port 26 is located on
the front side in the rotation direction of the rotor 74 relative
to the first suction port 22. The second discharge port 28 is
located on the front side in the rotation direction of the rotor 74
relative to the second suction port 24. It is also possible to form
the ports 22, 24, 26, 28 only in the side plate 37, instead of
forming these ports so as to straddle both the side plate 37 and
the body 44.
[0042] The side plate 37 communicates with the inner peripheral
ends of the slits 80, into which the vanes 81 defining the pump
chambers P are fitted, between the first suction port 22 and the
first discharge port 26. The first backpressure groove 62 and the
second backpressure groove 64 that supply a backpressure for
pressing the vanes 81 against the inner peripheral cam surface 78
are formed in a semi-annular shape in the circumferential direction
of the side plate 37. The first backpressure groove 62 and the
second backpressure groove 64 communicate with the first
backpressure oil passage 35 and the second backpressure oil passage
36, respectively.
[0043] When the vane pump 14 is started according to the driving of
the engine 15 and the rotor 74 is rotated in the clockwise
direction in FIG. 2, the working fluid inside the oil pan 18 is
suctioned through the suction oil passage 34 into the first suction
port 22 and the second suction port 24, and carried to each pump
chamber P of the vane pump 14 of which the volume increases
gradually as the rotor 74 rotates. As the rotor 74 rotates and the
volumes of the pump chambers P decrease accordingly, the working
fluid suctioned into the pump chambers P is discharged through the
first discharge port 26 and the second discharge port 28 to the
first discharge oil passage 30 and the second discharge oil passage
31, respectively. The oil pressure in the first backpressure oil
passage 35 and the second backpressure oil passage 36 is supplied
as a backpressure for pressing the radially outer end surfaces of
the vanes 81 defining the pump chambers P against the inner
peripheral cam surface 78 of the cam ring 70.
[0044] The check valve 90 is provided in the oil passage that
connects the first and second backpressure oil passages 35, 36 and
the first and second discharge oil passages 30, 31 to each other.
The check valve 90 opens when the oil pressure of the working fluid
in the discharge oil passages 30, 31 discharged from the vane pump
14 is higher than the oil pressure in the backpressure oil passages
35, 36, and the check valve 90 closes and blocks the flow of the
working fluid when the oil pressure of the working fluid in the
discharge oil passages 30, 31 discharged from the vane pump 14 is
equal to or lower than the oil pressure in the backpressure oil
passages 35, 36. In this way, the backpressure for pressing the
radially outer end surfaces of the vanes 81 defining the pump
chambers P of the vane pump 14 against the inner peripheral cam
surface 78 of the cam ring 70 is maintained.
[0045] Thus, the check valve 90 is provided in the vehicle
hydraulic device 10 of the first embodiment, which makes it
possible to operate the vane pump 14 smoothly even at the start of
the vane pump 14 by maintaining the oil pressure in the
backpressure oil passages 35, 36 connected to the vane pump while
the vane pump 14 is stopped. The check valve 90 opens when the oil
pressure of the working fluid in the discharge oil passages 30, 31
discharged from the vane pump 14 is higher than the oil pressure in
the backpressure oil passages 35, 36, and the check valve 90 closes
and shuts off the flow of the working fluid when the oil pressure
of the working fluid in the discharge oil passages 30, 31
discharged from the vane pump is equal to or lower than the oil
pressure in the backpressure oil passages 35, 36. With such a check
valve 90 provided between the backpressure oil passages 35, 36 and
the discharge oil passages 30, 31, the oil pressure control device
12, to which the working fluid is supplied from the vane pump 14,
is filled with the working fluid. Then, the check valve 90 opens at
the point in time when the oil pressure in the discharge oil
passages 30, 31 communicating with the oil pressure control device
12 has risen and exceeded the oil pressure in the backpressure oil
passages. Thus, the check valve 90 is prevented from opening and
closing repeatedly, so that the durability of the check valve 90 is
improved.
[0046] Moreover, in the first embodiment, the check valve 90 is
provided in the backpressure oil passages 35, 36 to which the
working fluid is supplied at a lower flow rate, so that especially
the torque loss of the vane pump 14 can be reduced during
high-speed rotation of the vane pump 14 compared with when the
check valve 90 is provided in the discharge oil passage 29 to which
the working fluid is supplied at a higher flow rate.
[0047] Next, a second embodiment will be described. In the
following second embodiment, those parts that have substantially
the same functions as in the first embodiment will be denoted by
the same reference signs and the detailed description thereof will
be omitted. The vehicle hydraulic device 10 of the second
embodiment is different from that of the first embodiment in that
the check valve 90 is built inside a second side plate 40, and that
a plurality of side plates, a first side plate 38, the second side
plate 40, and a third side plate 42 having oil passages
accompanying the check valve, are used. Therefore, only such
differences in configuration will be described in detail using FIG.
3 to FIG. 11.
[0048] FIG. 3 is a sectional view of the vane pump 14. The body 44
is provided with a first discharge opening 54 and a second
discharge opening 56 communicating with the inside of the recess
16. The third side plate 42 and the second side plate 40 are fitted
inside the recess 16 of the body 44 so as to be unable to rotate
relative to the body 44. The cam ring 70 is fitted so as to be
unable to rotate relative to the body 44, and the rotor 74 radially
housing the plurality of vanes 81 inside is installed inside the
recess 16 of the body 44. The first side plate 38 is fitted inside
the recess 16 of the body 44 so as to be unable to rotate relative
to the body 44. A cover 72 is mounted so as to cover the opening of
the recess 16 of the body 44, and the cover 72 is provided with a
first suction opening 46, a second suction opening 48, and a pump
shaft insert hole 77 through which the pump shaft 76 is passed.
[0049] The description of the structures and functions of the
plurality of vanes 81 and the rotor 74 housed inside the cam ring
70, which are the same as described in the first embodiment, will
be omitted. The oil passages inside the vane pump 14, and a first
check valve 98 and a second check valve 99, each functioning as the
check valve, will be described in the order from the suction to
discharge of the working fluid, i.e., in the order of the cover 72,
the first side plate 38, the second side plate 40, the third side
plate 42, and the body 44.
[0050] FIG. 4 is a front view of the cover 72. The cover is
provided with the first suction opening 46 and the second suction
opening 48 connected to the suction oil passage 34, and the pump
shaft insert hole 77 at the center of the cover. Since the pump
shaft insert hole 77 is also provided in each of the first side
plate 38, the second side plate 40, the third side plate 42, and
the body 44, the description of the pump shaft insert hole 77 will
be omitted from the subsequent description. FIG. 5 is a front view
of the first side plate 38 as seen from the side of the cover 72.
The first side plate 38 has a first suction opening 46a connected
to the first suction opening 46 and a second suction opening 48a
connected to the second suction opening 48.
[0051] Since the working fluid is sent to the pump chambers P
through the first suction opening 46 of the cover 72 of FIG. 4 and
the first suction opening 46a of the first side plate 38, these
openings correspond to the first suction port 22 of the first
embodiment. Since the working fluid is sent to the pump chambers P
through the second suction opening 48 of the cover 72 and the
second suction opening 48a of the first side plate 38, these
openings correspond to the second suction port 24 of the first
embodiment.
[0052] FIG. 6 is a rear view of the first side plate 38. On the
rear side of the first side plate 38, a first backpressure groove
63a and a second backpressure groove 65a, each functioning as the
backpressure oil passage, are formed in a semi-annular shape in the
circumferential direction around the pump shaft insert hole 77. The
first backpressure groove 63a and the second backpressure groove
65a supply a backpressure to be applied to the vanes 81.
[0053] FIG. 7 is a front view of the second side plate 40 as seen
from the side of the cover 72. The second side plate 40 has a first
backpressure groove 63b and a second backpressure groove 65b, each
functioning as the backpressure oil passage, formed as semi-annular
grooves in the circumferential direction around the pump shaft
insert hole 77. The backpressure grooves 63b, 65b supply a
backpressure to be applied to the vanes 81. The openings of the
first backpressure groove 63b and a first bypass passage 82b of
FIG. 8 functioning as the backpressure oil passage partially
overlap and communicate with each other, while the openings of the
second backpressure groove 65b and a second bypass passage 84b of
FIG. 8 functioning as the backpressure oil passage partially
overlap and communicate with each other. The first discharge groove
50b is open in the same shape and at the same position as a first
discharge groove 50c of the third side plate 42 of FIG. 9, and
communicates with the first discharge opening 54 of the body, while
the second discharge groove 52b is open in the same shape and at
the same position as a second discharge groove 52c of the third
side plate 42 of FIG. 9, and communicates with the second discharge
opening 56 of the body. Since the first discharge grooves and the
second discharge grooves carry the working fluid from the pump
chambers P, these grooves correspond to the first discharge port 26
and the second discharge port 28 of the first embodiment. A first
suction groove 58 and a second suction groove 60 are formed at
positions corresponding to the first suction opening 46a and the
second suction opening 48a that are provided in the first side
plate 38 across the rotor 74, and since the first suction groove 58
and the second suction groove 60 have a wide opening, the amount of
working fluid required for the pump chambers P defined by the vanes
81 is supplied.
[0054] FIG. 8 is a rear view of the second side plate 40. On the
rear side of the second side plate 40, the first discharge groove
50b and the second discharge groove 52b are fully open, and the
first bypass passage 82b holding the first check valve 98 and the
second bypass passage 84b holding the second check valve 99 are
provided. As the first bypass passage 82b and the second bypass
passage 84b of FIG. 8 are partially open, these bypass passages
partially communicate with the first backpressure groove 63b and
the second backpressure groove 65b, respectively.
[0055] FIG. 9 is a rear view of the third side plate 42. On the
rear side of the third side plate 42, the first discharge groove
50c and the second discharge groove 52c are fully open, and a first
bypass passage 82c and a second bypass passage 84c are formed. The
first bypass passage 82c and the second bypass passage 84c are each
formed of two semi-circular through-grooves.
[0056] FIG. 10 is a front view of the body. With the circular
recess 16 open at the end formed in an outer center part of the
body 44, the body 44 has a one-end-closed cylindrical shape. The
first discharge opening 54 connected to the first discharge oil
passage 30 is formed so as to penetrate the bottom wall of the body
44. Similarly, the second discharge opening 56 connected to the
second discharge oil passage 31 is formed so as to penetrate the
bottom wall of the body 44. The bottom wall further has a first
bypass groove 86 formed of an annular groove formed at a position
corresponding to the first bypass passage 82b of the second side
plate 40 and a groove providing communication between that annular
groove and the first discharge opening 54. Moreover, the bottom
wall has a second bypass groove 88 formed of an annular groove
formed at a position corresponding to the second bypass passage 84b
of the second side plate 40 and a groove providing communication
between that annular groove and the second discharge opening
56.
[0057] FIG. 11 is a sectional view of the major part showing the
second side plate 40, in which one of the first check valve 98 and
the second check valve 99 is incorporated, the third side plate 42,
and the body 44. The first check valve 98 and the second check
valve 99 are held respectively inside the first bypass passage 82b
and the second bypass passage 84b of the second side plate 40, and
similarly composed of three members, a retainer 92, a leaf spring
94, and a sheet 96. In the following, the first check valve 98 will
be described as a representative while the description of the
second check valve 99 will be omitted.
[0058] FIGS. 12A, 12B, 12C are front views of the retainer 92, the
leaf spring 94, and the sheet 96, constituting the first check
valve 98, as seen from the side of the body 44. The retainer 92 and
the leaf spring 94 have a ring shape. The sheet 96 has a disc shape
with a circular opening at the center. The retainer 92 holds the
leaf spring 94 inside the first bypass passage 82b and the second
bypass passage 84b. The leaf spring 94 applies a force for pressing
the sheet 96 against a columnar part provided at the center of the
bypass passage 82c of the third side plate 42. Under the force of
the leaf spring 94, the circular opening at the center of the sheet
96 comes into contact with the surface of the third side plate 42,
so that the opening of the sheet 96 is closed and the flow of the
working fluid is blocked. Thus, the sheet 96 constituting a part of
the first check valve 98 has one side surface in contact with the
working fluid on the discharge opening side and the other side
surface in contact with the working fluid on the backpressure
groove side. Accordingly, the oil passage opens when the oil
pressure of the working fluid at the first discharge opening 54
discharged from the vane pump 14 is higher than the oil pressure in
the backpressure grooves of the rotor 74, the first side plate 38
and the second side plate 40, and the oil passage closes and the
flow of the working fluid is blocked when the oil pressure is equal
to or lower than the oil pressure in the backpressure grooves. In
this way, the backpressure for pressing the radially outer end
surfaces of the vanes 81 defining the pump chambers P of the vane
pump 14 against the inner peripheral cam surface 78 of the cam ring
70 is maintained. Although the members constituting the first check
valve 98 have been described as having a circular shape in a front
view in the second embodiment, these members do not particularly
have to be circular and may instead have a square shape or a
polygonal shape, for example.
[0059] Thus, the vehicle hydraulic device 10 of the second
embodiment is provided with the first check valve 98 and the second
check valve 99, which makes it possible to operate the vane pump 14
smoothly even at the start of the vane pump 14 by maintaining the
oil pressure in the first backpressure groove 62 and the second
backpressure groove 64 inside the rotor 74 of the vane pump while
the vane pump 14 is stopped.
[0060] The first check valve 98 and the second check valve 99 open
at the point in time when the oil pressure control device 12, to
which the working fluid is supplied from the vane pump 14 by the
first check valve 98 and the second check valve 99, has been filled
with the working fluid and the oil pressure in the discharge oil
passages 30, 31 communicating with the oil pressure control device
12 has risen and exceeded the oil pressure in the backpressure oil
passages 35, 36. Thus, the first check valve 98 and the second
check valve 99 are prevented from opening and closing repeatedly,
so that the durability of the first check valve 98 and the second
check valve 99 is improved.
[0061] Moreover, when the first check valve 98 and the second check
valve 99 are provided in the first bypass passage 82b and the
second bypass passage 84b to which the working fluid is supplied at
a lower flow rate, especially the torque loss of the vane pump 14
during high-speed rotation of the vane pump 14 can be reduced
compared with when the check valve 90 is provided in the discharge
oil passage 29 to which the working fluid is supplied at a higher
flow rate.
[0062] While the present embodiments have been described above in
detail with reference to the drawings, the present disclosure can
also be implemented in other embodiments, and various modifications
can be added within the scope of the disclosure.
[0063] For example, in the vane pump 14 of the first embodiment and
the second embodiment, the cam ring 70 having the inner peripheral
cam surface 78 is fitted in the recess 16 of the body 44. However,
the present embodiments are not limited thereto, and, for example,
the cam ring may be omitted by forming the inner peripheral cam
surface 78, facing the outer peripheral surface of the rotor 74,
directly on the inner peripheral surface of the recess 16 of the
body 44.
[0064] Although the vane pump of the second embodiment is provided
with the two check valves 98, 99, the present embodiments are not
limited thereto and the number of the check valves may be one or
more than two.
[0065] The vane pump of the second embodiment has been described
with three types of side plates, but the present embodiment is not
limited thereto. For example, it is also possible to omit the first
side plate by machining the backpressure grooves 63a, 65a of the
first side plate in the cover 72, or to omit the third side plate
42 and reduce the number of the side plates by machining the bypass
grooves inside the body, instead of on the surface of the body as
in the above embodiment. Alternatively, the number of the side
plates may be increased to make the machining of the oil passage
easier.
* * * * *