JPH11201058A - Hydraulic pump, and brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve pump performance by reducing the capacity of a pump chamber of a hydraulic pump used in a brake system provided with a drive slip regulation device and an anitlock device. SOLUTION: A device is provided with a cylindrical cylinder 8a, a plunger 8c slidably contained in the cylinder 8a, and a pump chamber 8d formed between that and the cylinder 8a. The pump chamber 8d is communicated to a reservoir 5 and a wheel cylinder WC of a brake system provided with a drive slip regulation device and an antilock device through a first suction valve 8e, it is communicated wit a master cylinder MC of the brake system through a second suction valve 8f and a normally closed solenoid valve 41, and it is communicated with the master cylinder MC and the wheel cylinder WC of the brake system through a discharge valve 8 m. The first and the second suction valves 8e, 8f are provided in the pump chamber 8d, and a coil spring is provided between the suction valves 8e, 8f in a compressed condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a hydraulic pump and a brake device using the hydraulic pump.

[0002]

2. Description of the Related Art Conventionally, as a brake control device for performing ABS control and motion stabilization control, for example, Japanese Patent Application Laid-Open No. 7-50 / 1990
No. 106 is known.

In this prior art, an ABS unit is provided in the middle of a brake circuit connecting a master cylinder as an operating hydraulic pressure generating means and a wheel cylinder of each wheel.
The ABS unit includes a hydraulic control valve including an inflow valve and an outflow valve for controlling the hydraulic pressure of a wheel cylinder, a reservoir for temporarily storing brake fluid discharged from the hydraulic pressure control valve,
A main pump for sucking the brake fluid from the reservoir and returning it to the brake circuit. Further, the main pump is a sub-pump (supply pump) via a normally closed solenoid valve (in-side gate valve) that is opened only during exercise stabilization control.
And the brake fluid is sucked from the master cylinder side.

[0004] Therefore, at the time of exercise stability control, even if the brake operation is not performed, the main pump sucks the supply fluid pressure by the sub-pump and the brake fluid from the master cylinder side and discharges it to the brake circuit. The pressure of the wheel cylinder is increased by the discharged brake fluid to generate a braking force.

[0005] As a pump used for the main pump, a plunger type hydraulic pump in which a plunger is reciprocated by rotating a cam is known. The structure of this hydraulic pump is briefly shown in FIG. 5, that is, 101 is a cam rotated by a motor, and 103 is a plunger whose base end is in contact with this cam. . The plunger 103 is housed in a cylinder 104, and forms a pressure chamber 105 between the tip of the plunger 103 and the bottom of the cylinder 104. The pressure chamber 105 is connected to a discharge circuit 107 connected to a brake circuit via a discharge valve 106 provided at the bottom of the cylinder 104, while being connected via a suction valve 108 provided inside the plunger 104. , A first suction circuit 110 connected to the reservoir 109 and a second suction circuit 111 connected to the master cylinder. In the middle of the second suction circuit 111, an in-side gate valve 112 is provided. Further, a seal member 113 is provided between the plunger 103 and the cylinder 104.

In the hydraulic pump, during the ABS control, the reservoir 10 is closed because the in-side gate valve 112 is closed.
The brake fluid of No. 9 is sucked, compressed in the pressure chamber 105, and discharged to the brake circuit via the discharge circuit 107. Also,
During the motion stabilization control, the in-side gate valve 112 is opened, and the brake fluid is not normally discharged to the reservoir 109 at this time. Therefore, the brake fluid is supplied from the master cylinder or the sub pump through the second suction circuit 111. It is sucked and discharged to the brake circuit via the discharge circuit 107.

[0007]

By the way, in the above-mentioned prior art, the first suction circuit 110 and the second suction circuit 1
One suction valve 10 as a valve for preventing backflow to
8, only the two suction circuits 110,
In this configuration, the suction valve 108 is provided at a portion where the two suction circuits 111 and 111 are joined.
Is formed through the inside of the plunger 103 through a communication hole 115 formed at a position overlapping with the plunger 103 in the entire stroke area of the plunger 103 in the cylinder 104, and the suction valve 108 is provided at a portion passing through the inside of the plunger 103. Have been.

However, the prior art having such a structure has the following problems.

In other words, the main pump is configured to open the in-side gate valve 112 and draw in the sub-pump and the brake fluid on the master cylinder side during the motion stabilization control. Performs the brake operation and generates the master cylinder pressure.
This master cylinder pressure is supplied to the second suction circuit 11 as it is.
1 is led between the plunger 103 and the cylinder 104. Therefore, the pressure between the suction valve 108 and the seal member 113 becomes considerably high, and a high load is applied to the seal member 113. Therefore, it is necessary to add a pressure-resistant backup ring to the seal member 113. In addition, because it becomes a high-pressure pump, the sliding resistance becomes large and the pump performance decreases,
There has been a problem that a check valve is required in the reservoir suction line in order to prevent penetration into the reservoir. And
As a countermeasure, a master cylinder pressure sensor, a pedal stroke sensor, and the like are provided, and the in-side gate valve 112 at which the master cylinder pressure becomes equal to or higher than a predetermined pressure is closed, so that a predetermined pressure is applied between the suction valve 108 and the seal member 113. Means have been taken to prevent this from happening, but such a configuration would significantly increase the cost.

Therefore, a brake device shown in FIG. 6 has been developed to solve the above-mentioned problems. The brake device includes an operating hydraulic pressure generating means (master cylinder) MC for generating a hydraulic pressure in response to a driver's operation of a brake pedal BP, and a wheel cylinder for generating a braking force between the operating hydraulic pressure generating means MC and wheels. WC (FL), W
A brake circuit BR connecting C (RR), WC (FR), and WC (RL), and a hydraulic pressure control valve 3 provided in the middle of the brake circuit BR and capable of reducing, holding, and increasing the wheel cylinder pressure. , 4, a reservoir 5 provided in a drain circuit 6 connected to the hydraulic pressure control valves 3, 4, a brake fluid is sucked from the reservoir 5 through a first suction circuit 7, and The brake fluid is sucked from the reservoir tank RT of the generating means MC via the second suction circuit 32 and discharged to the brake circuit BR toward the hydraulic pressure control valves 3 and 4 via the discharge circuit 9 so as to be able to be discharged. The connected hydraulic pump 8, suction valves 8e and 8f for preventing backflow in the suction circuits 7, 32, a discharge valve 8m for preventing backflow in the discharge circuit 9, and an out-side gate for opening and closing the brake circuit BR. DOO valve 41 and, and a inside gate valve 42 for opening and closing the second intake circuit 32.
The hydraulic pump 8 includes a cylinder 8a and the cylinder 8a.
And a pressure chamber 8 formed between the cylinder 8a and the plunger 8c.
d is connected to the first and second suction circuits 7, 32 and the discharge circuit 9, and performs suction and discharge of brake fluid by changing the volume of the pressure chamber 8d as the plunger 8c strokes. The seal member 11 is provided between the outer periphery of the plunger 8c and the inner periphery of the cylinder 8a. The control unit that controls the operation of the pump, the hydraulic pressure control valve, and the gate valves performs anti-lock brake control that performs hydraulic pressure control to prevent the wheels from locking when the operating hydraulic pressure generating means is operating. In addition, motion stabilization control is performed, which is one of torque control for preventing at least driving wheel slip according to vehicle behavior or yaw rate control for generating yaw rate in a direction to stabilize the vehicle attitude by the generated braking force. It is configured as follows.

By the way, in the brake device,
As shown in an enlarged view in FIG. 7, the hydraulic pump 8 has a suction hole formed in the cylinder 8a for communicating the second suction circuit 32 and the pressure chamber 8d at a position outside the stroke range of the plunger 8c. And the second
The suction valve 8f for preventing backflow of the suction circuit 32 is connected to the cylinder 8a.
However, there is a problem as described below because it is provided outside.

(1) A circuit (part of the second suction circuit 32) 32a for communicating the cylinder 8a with the suction valve 8f.
In order to reduce the flow resistance of the brake fluid, the diameter of the circuit 32a must be increased, and the diameter of the oil passage must be increased and the suction valve 8f must be enlarged.

(2) Since the volume of the pressure chamber 8d of the hydraulic pump 8 and the volume between the pressure chamber 8d and the suction valve 8f become large, the pump compression ratio becomes small and the pump performance is reduced. Further, in order to increase the pump compression ratio, it is necessary to increase the size of the pump.

The present invention has been made to solve the above problems.

[0015]

SUMMARY OF THE INVENTION The present invention provides a cylindrical cylinder having an open end at least at one end, and slidably housed in the cylinder with one end protruding from the open end of the cylinder. A plunger having one end abutting against a cam rotated by a driving means, being urged by an urging means in a contacting direction with the cam, and reciprocating with the rotation of the cam; and the other end of the plunger. And a pump chamber formed between the cylinder and the cylinder. The pump chamber is provided with a drive slip adjusting device and an anti-lock device via one of the first and second two suction valves. It is connected to the reservoir and the wheel cylinder of the hydraulic brake device equipped with the device, and is connected to the master cylinder of the brake device via the other intake valve and the normally closed solenoid valve. In a hydraulic pump connected to a master cylinder and a wheel cylinder of the brake device via a discharge valve, the first suction valve is disposed on an end face of the plunger facing the pump chamber, and the second suction valve is provided. A valve is disposed on the inner surface of the cylinder facing the end surface of the plunger in the pump chamber, and a coil spring is interposed between the first suction valve and the second suction valve in a compressed state. I let it.

Accordingly, the first suction valve is pressed at one end side of the coil spring and pressed against a valve seat provided on the plunger to close an oil passage provided on the plunger and to release the second suction valve. Is pressed by the other end of the coil spring and pressed against a valve seat provided in the cylinder to close an oil passage provided in the cylinder.

When the first suction valve moves away from the valve seat against the spring force of the spring, the brake fluid from the reservoir and the wheel cylinder passes directly through the first suction valve to the pump. Inhaled indoors. When the second suction valve moves away from the valve seat against the spring force of the spring, the brake fluid from the master cylinder is directly sucked into the pump chamber through the second suction valve.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall view of a brake device using a hydraulic pump according to a first embodiment of the present invention.

In the figure, WCFL is a wheel cylinder for the left front wheel, WCRR is a wheel cylinder for the right rear wheel, and WC
RR is the right front wheel cylinder, WCRL is the left rear wheel cylinder, MC is each wheel cylinder WCFL
To RL as a hydraulic pressure source. The master cylinder MC is configured to supply hydraulic pressure to the brake circuit BR in conjunction with the depression of the brake pedal BP, and is provided with a reservoir tank RT for storing brake fluid.

The brake circuit BR is connected to a first channel circuit 1 connected to the left front wheel and right rear wheel side wheel cylinders WCFL, WCRR, and to the right front wheel and left rear wheel side wheel cylinders WCFR, WCRL. And two channels of X piping with the second channel circuit 2. In addition, the wheel cylinder WCFL ~
When RL is not specified, it is denoted as WC.

Hereinafter, the configuration will be described in detail. Since the configurations of both channel circuits 1 and 2 are the same, the first configuration will be described below.
Only the configuration of the channel circuit 1 will be described, and the same components in both the channel circuits 1 and 2 will be assigned the same reference numerals, and description of the configuration of the second channel circuit 2 will be omitted.

The first channel circuit 1 has a branch point 1d
, A front wheel branch circuit 1f leading to a left front wheel cylinder WCFL and a right rear wheel cylinder WCRR
And a rear wheel branch circuit 1r.

Each of the branch circuits 1f and 1r is provided with an inflow valve 3 and an outflow valve 4 which constitute a hydraulic pressure control valve for reducing, holding and increasing the brake fluid pressure of each wheel cylinder WC. That is, the inflow valve 3 is provided in the middle of each of the branch circuits 1f and 1r, and when the non-operation is performed, the branch circuits 1f and 1r are respectively connected to each other by a spring force, and the operation of the respective branch circuits 1f and 1r is interrupted. It is composed of an open 2-port 2-position electromagnetic switching valve. Further, the outflow valve 4 is closer to the wheel cylinder WC than the inflow valve 3 of each of the branch circuits 1f and 1r (hereinafter, a side relatively closer to the master cylinder MC in each of the channel circuits 1 and 2 is referred to as an upstream, It is provided in the middle of a drain circuit 6 branched from branch points 1e, 1e provided at the branch point 1e, 1e provided to the reservoir 5 at a position near the cylinder WC. And a normally closed 2-port 2-position electromagnetic switching valve. Each branch circuit 1
f and 1r are provided with an inflow valve bypass passage 1h having a valve 1g while bypassing the inflow valve 3 and allowing only the flow from downstream to upstream on the way.

The drain circuit 6 includes a main suction circuit 7
Through a hydraulic pump (hereinafter referred to as a main pump) 8 of the present invention.

As shown in an enlarged view in FIG. 2, the main pump 8 has a cylindrical cylinder 8a having at least one open end, and a cylinder 8a having one end protruding from the open end of the cylinder 8a. Slidably accommodated, the one end of which is brought into contact with a cam C which is rotated by a driving means, and is urged by an urging means 8b in the direction of contact with the cam C. Reciprocating plunger 8c
And a pump chamber 8d formed between the other end of the plunger 8c and the cylinder 8a.

In the pump chamber 8d, first and second 2
Two suction valves 8e and 8f are provided.

The first suction valve 8e is provided at the tip end surface of the plunger 8c (the surface opposite to the surface on which the cam C contacts).
, And the second suction valve 8f is disposed on the inner surface of the cylinder facing the distal end surface of the plunger 8c.

The first suction valve 8e and the second suction valve 8f
Between them, a coil spring 8g is interposed in a compressed state.

The first suction valve 8e is pressed against the first valve seat 8h by the spring force of the coil spring 8g to close the suction passage 8i provided in the plunger 8c, and the second suction valve 8e is closed. 8f is the coil spring 8
It is pressed against the second valve seat 8k by the spring force of g to close the suction passage 81 provided in the cylinder 8a.

The pump chamber 8d is connected to the main suction circuit 7 via a first suction valve 8e and a suction passage 8i, and the main suction circuit 7 and the drain circuit 6
The reservoir 5 and the wheel cylinder WCF
L, WCRR, etc., and is connected via a second suction valve 8f and a suction passage 8l to a charging circuit 32, which will be described later. And the master cylinder MC.

The main pump 8 has a discharge valve 8
m is provided. The discharge valve 8n is mounted on the cylinder 8a. The discharge valve 8m is pressed against a third valve seat 8p by a third spring 8n to open and close the discharge passage 8q.

The pump chamber 8d is connected to the main discharge circuit 9 via the discharge passage 8q and the discharge valve 8m, and is connected to the master cylinder MC via the main discharge circuit 9.
And the wheel cylinders WCFL, WCRR and the like. A seal member 11 is provided between the cylinder 8a and the plunger 8c. Further, between the cylinder 8a and the pump hole HH of the housing HA,
A first to third sliding seals 12 to 14 are attached, and the suction passage 8i provided in the plunger 8c by the sealing member 11 and the first and second sliding seals 12 and 13.
Are sealed, and the third sliding seal 14 seals one side of the suction passage 8l provided in the cylinder 8a. A damper 10 for absorbing a discharge pulse pressure is provided in the main discharge circuit 9.

The main pump 8, the inflow valve 3 and the outflow valve 4 constitute an ABS unit. That is, when the wheel lock occurs when each wheel cylinder WC performs the braking operation, if the inflow valve 3 is closed and the outflow valve 4 is opened, the brake fluid pressure of the wheel cylinder WC is released to the reservoir 5. And the braking force is weakened to release the wheel lock. If the inflow valve 3 and the outflow valve 4 are closed in this state, the brake fluid pressure of the wheel cylinder WC is maintained and the wheel lock is released. When the inflow valve 5 is opened and the outflow valve 4 is closed, the brake fluid pressure is supplied to the wheel cylinder WC, and the braking force is increased.
By such an operation, the maximum braking force is obtained within a range in which the wheel lock is prevented. While the above-described ABS operation is performed, the main pump 8 is driven to suck the brake fluid drained to the reservoir 5 and discharge the brake fluid to the first channel circuit 1.

A brake circuit check valve 21 is provided in the middle of the first channel circuit 1 and at a position upstream of the branch point 1d to brake the first channel circuit 1 from upstream to downstream. Allows the liquid to flow, but regulates the flow from downstream to upstream. An out-side gate valve 41 is provided in a bypass circuit 31 that bypasses the brake circuit check valve 21. This out side gate valve 41
Is constituted by a normally open 2-port 2-position solenoid-operated switching valve which makes the first channel circuit 1 communicate with the spring force when not in operation and shuts off the first channel circuit 1 when in operation.

As described above, one end of the feeding circuit 32 is connected to the second suction valve 8f of the main pump 8. In the middle of the feeding circuit 32, an in-side gate valve 42 composed of a normally-closed 2-way 2-position electromagnetic switching valve.
Is provided, and the other end of the supply circuit 32 is connected to a supply chamber 51 a of the supply piston 51.

The supply piston 51 has a cylinder 52 defined by a supply chamber 51a and a pressure introduction chamber 51b, and a piston 53 is slidably provided. And the feeding room 5
1 a is connected to the feeding circuit 32 and the first channel circuit 1. The piston 53 is urged by a return spring 54 in a direction to contract the pressure introduction chamber 51b, and the piston 53 has a check valve 53a.
Is provided.

The check valve 53a is supported by the piston 53 so as to be slidable in the axial direction, and is urged in a direction away from the piston 53 by a check spring 53b. Therefore, this check valve 5
3a closes (closes) the opening connected to the first channel circuit 1 when the piston 53 slides by a predetermined amount in the direction in which the supply chamber 51a is contracted.
When the pressure in the first channel circuit 1 becomes higher than the supply chamber 51a by a predetermined pressure, the check spring 58b is shortened and opened. When the piston 53 further slides to shorten the check spring 53b, the check valve 53a cannot be opened. As described above, the check valve 53a is set to the first position in accordance with the sliding amount of the piston 53.
It is configured to switch between a state having a check function for releasing the brake fluid pressure of the channel circuit 1 to the supply circuit 32 and a state where the check function cannot be exhibited.

In the charging circuit 32, a position on the charging piston 51 side of the in-side gate valve 42 and the first channel circuit 1 are connected by a relief circuit 34 having a relief valve 43 in the middle.

The pressure introduction chamber 51b of the charging piston 51
Is pressurized by a sub (supply) pump 61. The sub-pump 61 is driven by rotation of a cam provided coaxially with the cam of the main pump 8 to perform suction and discharge.
A charge / discharge circuit 63 having a discharge valve 62 and a charge / suction circuit 65 having a suction valve 64 are connected.

The first and second channel circuits 1, 2
The pressure introduction chambers 51b of the supply piston 51 are connected by an annular pressure introduction circuit 33, and the supply / discharge circuit 63 is connected to the pressure introduction circuit 33, while the supply / supply suction circuit 65 is connected to the master cylinder. It is connected to the reservoir tank RT of the MC. Therefore, when the sub-pump 61 is driven, the brake fluid in the reservoir tank RT is sucked, discharged to the pressure introducing circuit 33, and further supplied to the pressure introducing chamber 51b.

The pressure introduction circuit 33 and the charging / suction circuit 6
5 is connected via a circulation circuit 37 and a relief circuit 38, a normally open circulation switching valve 45 is provided in the middle of the circulation circuit 37, and a relief valve 46 is provided in the middle of the relief circuit 38. Is provided.

The main unit of the above-described brake device housed in the housing HA is a brake unit BU, which is indicated by a dashed line in FIG. The brake unit BU is mounted at a predetermined position in an engine room (not shown) of the vehicle.

As shown in FIG. 3, the operation of each of the valves 3, 4, 41, 42, 45 of the solenoid valve structure and the motor M which is the drive source of the main pump 8 and the sub-pump 61 is controlled by the control unit CU. . That is, the control unit CU includes a wheel speed sensor S for detecting the rotation speed of the wheels (not shown), a yaw rate sensor YR for detecting the yaw rate of the vehicle body, a steering angle sensor H for detecting the steering angle of the vehicle, and whether the brake operation state is in effect. And a sensor group SG having a G sensor GS for detecting the longitudinal acceleration and deceleration of the vehicle are connected to the control unit CU, based on signals input from these sensor groups SG. The slip rate of each wheel is obtained, and when the slip rate becomes a predetermined value or more during braking, ABS control is performed to reduce the slip rate, and when the vehicle behavior is in a direction that impairs stability, control is performed in a direction to stabilize this. Execute exercise stability control. The motion stabilization control includes a torque control that suppresses a drive wheel slip when it occurs, and a torque control that generates a braking force on a predetermined wheel to stabilize the vehicle when the posture of the vehicle is likely to be disturbed. It is configured with at least one of yaw rate control for generating a yaw rate. Note that the details of each control are not features of the present invention, and therefore detailed description is omitted.

Next, the operation of the brake device will be described. The operation of the first and second channel circuits 1 and 2 is the same in this operation, and therefore only the first channel circuit 1 will be described.

A) During Normal Brake Operation Normally, the valves 3, 4, 41, 42, and 45 are in a non-operating state shown in the figure. When the brake pedal BP is depressed in this state, the master cylinder MC The generated brake fluid pressure is transmitted to each wheel cylinder WC through each of the branch circuits 1f and 1r through the first channel circuit 1 through the out-side gate valve 41 and the inflow valve 3, and the brake pedal BP
Braking is performed according to the pedaling force of the vehicle.

B) At the time of ABS control When the wheels are locked or are likely to be locked during the above-described brake operation, the control unit CU sets the wheel slip ratio within a predetermined range and locks the wheels. ABS control is performed to prevent the above. That is, the ABS control reduces, maintains, and increases the brake fluid pressure so that the wheels do not lock during braking. First, the brake fluid pressure generated by the above-described brake operation is applied to either the left front wheel or the right rear wheel. When one or both of the slip ratios become a predetermined value abnormal, the drive of the motor M is started, and the inflow valve 3 of the branch circuits 1r and 1f connected to the wheel cylinder WC for braking the wheel which is likely to be locked is closed. Then, the outflow valve 4 is opened. As a result of the closing of the inflow valve 3, the pressure in the wheel cylinder WC is not increased, and the brake fluid in the wheel cylinder WC is discharged to the reservoir 5 through the drain circuit 6 to be reduced in pressure, thereby weakening the braking force. The brake fluid stored in the reservoir 5 is sucked into the main pump 8 and returned from the main discharge circuit 9 to the first channel circuit 1.

When the wheel slip rate falls below a predetermined value as a result of the decrease in the braking force, the control unit CU stops supplying power to the outflow valve 4 and
Is closed to maintain the hydraulic pressure of the wheel cylinder WC,
Further, as a result of the holding operation, when the slip ratio falls below another predetermined value, the power supply to the inflow valve 3 is cut off and the valve is opened. The liquid is supplied to the wheel cylinder WC, and the braking force is increased again.

By repeating the above operation, while the brake pedal BP is being depressed, the slip ratio of each wheel is kept within a predetermined range, and the maximum braking force is obtained while preventing the wheels from being locked. Is performed.

In the above ABS control, the main pump 8 does not suck the brake fluid from the supply circuit 32 because the in-side gate valve 42 is kept closed.

At this time, since the circulation switching valve 45 is opened, the sub-pump 61 uses
Only by circulating the brake fluid in the path from the pressure introduction circuit 33 to the circulation circuit 37 to the charging suction circuit 65, the pressure introduction chamber 51
b is not pressurized and does not load the motor M.

C) At the time of motion stabilization control The torque slip control for keeping the slip ratio within a predetermined range in response to the increase of the slip ratio of the drive wheels due to sudden start and sudden acceleration, or the vehicle attitude is likely to be disturbed. In response, the control unit CU drives the motor M and controls both gate valves 4 when performing motion stabilization control such as yaw rate control that generates a braking force that applies a yaw rate in a direction to stabilize the vehicle attitude.
1 and 42 and the circulation switching valve 45, the out-side gate valve 41 is closed to shut off the first channel circuit 1, and the in-side gate valve 42 is opened to supply the feed circuit 32.
And the circulation switching valve 45 is closed to shut off the circulation circuit 37.

Therefore, in the sub-pump 61, the circulation of the brake fluid up to that point is stopped, the brake fluid is introduced into the pressure introduction chamber 51b, and the piston 53 slides in the supply piston 51, and the brake fluid in the supply chamber 51a is discharged. It is supplied from the supply circuit 32 to the main suction circuit 7 of the main pump 8. Accordingly, the main pump 8 discharges the brake fluid to the first channel circuit 1 via the main discharge circuit 9 and increases, holds, and reduces the pressure of the wheel cylinder WC based on the operation of the inflow valve 3 and the outflow valve 4. As a result, a desired braking force is generated, and the vehicle attitude can be stabilized by torque control or yaw moment control.

Thereafter, when the motor M is stopped at the end of the motion stabilization control, the piston 53 of the feeding piston 51 slides to the original position by the urging force of the return spring 54, and the wheel cylinder is accordingly moved. The WC or the brake fluid in the reservoir 7 returns to the supply chamber 51a, and the brake fluid supplied to the pressure introduction chamber 51b returns to the reservoir tank RT.

FIG. 4 shows a second embodiment of the hydraulic pump 8 of the present invention. In this embodiment, a case where the housing HA has a function as a cylinder 8a of the main pump 8 is shown. The housing HA is provided with a pump hole HH, the plunger 8c is slidably mounted in the pump hole HH, and a second hole is provided between the plunger 8c and the pump hole HH. First to third sliding seals 12 to 14 are provided.

The first and second sliding seals 1
The two sides of the suction passage 8i provided in the plunger 8c are sealed with the second sliding seal 13 and the suction passage 8l is sealed with the third sliding seal 14.
Is sealed at one side. Further, the discharge valve 8n is disposed on the housing HA as the seal 8a or on the outside thereof. The other configuration is the same as that of the first embodiment, and thus the same components are denoted by the same reference numerals, and redundant description will be omitted.

[0057]

The hydraulic pump and brake device according to the present invention have the following effects.

(1) The hydraulic pump according to the first aspect of the present invention comprises two suction valves, a suction valve communicating with the wheel cylinder via a reservoir and a suction valve communicating with the master cylinder via a normally closed solenoid valve. Since it is housed in a room and a coil spring is interposed between the first and second suction valves in a compressed state, the conventional suction valve is sucked like a hydraulic pump provided outside the cylinder. It is not necessary to consider the arrangement position of the valve and the like, so that the layout property is improved and the oil passage configuration is simplified, so that the number of man-hours for oil passage processing is reduced and the cost can be reduced.

Also, since there is no oil passage connecting the suction valve and the pump chamber, the volume of the pump chamber is reduced by that much, and the compression ratio is increased by reducing the volume of the pump chamber, thereby improving the pump discharge performance. it can.

Further, by interposing the coil spring in a compressed state between the first suction valve and the second suction valve, the first and second two suction valves can be respectively seated by one coil spring. As a result, the number of parts and the number of assembling steps can be reduced as compared with the case where the first and second suction valves are pressed against the valve seats by separate coil springs.

(2) Since the brake device of the second aspect uses the hydraulic pump of the first aspect, the size of the brake device can be reduced, and the mountability on a vehicle can be improved.

(3) In the hydraulic pump and the brake device according to the third and fourth aspects, the discharge valve is seated on the valve seat provided on the cylinder, so that the number of parts is reduced and the discharge circuit is shortened. Can be.

[Brief description of the drawings]

FIG. 1 is an overall view of a brake device using a hydraulic pump according to the present invention.

FIG. 2 is a sectional view of the hydraulic pump according to the first embodiment.

FIG. 3 is a block diagram showing a control system.

FIG. 4 is a sectional view of a hydraulic pump according to a second embodiment.

FIG. 5 is a schematic sectional view of a conventional hydraulic pump.

FIG. 6 is an overall view of a conventional brake device.

FIG. 7 is a sectional view of a conventional hydraulic pump.

[Description of Signs] 5 ... Reservoir, 8 ... Hydraulic pump, 8a ... Cylinder, 8c
... plunger, 8d ... pump chamber, 8e ... first suction valve,
8f ... second suction valve, 8g ... coil spring, 8m ...
Discharge valve, 8q: Valve seat, MC: Master cylinder, WC ...
Wheel cylinder, 41 ... Normally closed solenoid valve.

Claims (4)

[Claims] 1. A cylindrical cylinder having an open end at least at one end, and the other end slidably housed in the cylinder with one end protruding from the open end of the cylinder. A plunger forming a pump chamber between an end side and a cylinder; a first suction valve facing the pump chamber and disposed on an end face of the plunger; and opposing an end face of the plunger in the pump chamber. A second suction valve disposed on the inner surface of the cylinder; and a first suction valve interposed between the first suction valve and the second suction valve. A hydraulic pump, comprising: a spring that presses against a second valve seat; and a discharge valve that discharges fluid that has flowed into the pump chamber via the first and second suction valves. . 2. An operating hydraulic pressure generating means for generating a hydraulic pressure in response to an operation of a brake pedal; a brake circuit connecting the operating hydraulic pressure generating means to a wheel cylinder for generating a braking force at a wheel; A hydraulic pressure control valve that is provided in the middle of the cylinder and controls the pressure reduction, holding, and pressure increase of the wheel cylinder pressure; a reservoir provided in a drain circuit connected to the hydraulic pressure control valve; While sucking the brake fluid through the circuit, and sucking the brake fluid from the reservoir tank of the operating fluid pressure generating means through the second suction circuit,
A hydraulic pump connected to the brake circuit so as to be able to discharge the brake fluid toward the hydraulic pressure control valve via a discharge circuit, wherein the hydraulic pump has an open end at least at one end. A cylindrical cylinder, and the other end is slidably housed in the cylinder with one end protruding from the open end of the cylinder, and a pump chamber is formed between the other end and the cylinder. And a plunger having one end contacting a cam rotated by driving means and reciprocating with the rotation of the cam; and a first plunger disposed on an end face of the plunger facing the pump chamber. A suction valve, a second suction valve disposed on the inner surface of the cylinder facing the end face of the plunger in the pump chamber, and interposed between the first suction valve and the second suction valve. , The first The second suction valve, a first respectively a spring is pressed against the second valve seat, the braking device, characterized in that it and a discharge valve for discharging the brake fluid from the pump chamber. 3. The hydraulic pump according to claim 1, wherein the discharge valve is seated on a valve seat provided on the cylinder. 4. The brake device according to claim 2, wherein the discharge valve is seated on a valve seat provided on the cylinder.