JPH11245792A - Vehicular hydraulic braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular hydraulic braking device, having a mechanical regulator, and being capable of changing the ratio of regulator hydraulic pressure to master cylinder hydraulic pressure. SOLUTION: This hydraulic braking device is equipped with a wheel cylinder, a reservoir 4, a master cylinder 1, an auxiliary hydraulic pressure source 6, and a mechanical regulator, respectively. The regulator is equipped with a housing having a stepped cylinder hole 51, a stepped piston 52, a hydraulic pressure chamber 52a being formed in space between a large diametral end of this stepped piston and the housing and communicating to the master cylinder, a pressure regulating chamber 52b corresponding to a small diametral end of the stepped piston, a hydraulic control valve selectively interconnecting the pressure regulating chamber to the auxiliary hydraulic pressure source or the reservoir, a annular car 52e having the pressure receiving area being equal to a difference between that one end of the stepped piston receives from the hydraulic pressure char and another pressure receiving area that the other end of the step piston receives from the pressure regulating chamber, and a selector valve SV2 selectively interconnecting the annular chamber to the pressure regulating chamber or the reservoir, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake system for a vehicle having a mechanical regulator for inputting an output power hydraulic pressure of an auxiliary hydraulic pressure source and adjusting the output hydraulic pressure to a regulator hydraulic pressure according to a master cylinder hydraulic pressure.

[0002]

2. Description of the Related Art As this kind of prior art, for example, an apparatus disclosed in Japanese Patent Laid-Open Publication No. 1-119449 is known. In this device, the pressure chamber of the master cylinder is connected to the wheel cylinder via a main hydraulic pressure passage. The main hydraulic pressure passage is a normally-open type on-off valve in order from the master cylinder side, and a brake hydraulic pressure applied to the wheel cylinder. Is provided. A mechanical regulator is connected to the main hydraulic pressure path between the pressure chamber of the master cylinder and the on-off valve, and this regulator boosts the brake fluid in the reservoir to a predetermined pressure and outputs a power hydraulic pressure source. It is connected to the. The regulator inputs the output power hydraulic pressure of the auxiliary hydraulic pressure source and regulates the output power hydraulic pressure to the regulator hydraulic pressure according to the output hydraulic pressure of the pressure chamber of the master cylinder. The output port of the regulator is connected to the main hydraulic path between the on-off valve and the modulator. In this device, during normal braking, the pressure chamber of the master cylinder communicates with the wheel cylinder via the main hydraulic pressure path, and the output hydraulic pressure of the master cylinder is applied to the wheel cylinder. On the other hand, during anti-skid control,
The on-off valve is switched to the closed position, the communication between the master cylinder and the wheel cylinder is cut off, and the regulator hydraulic pressure is supplied to the wheel cylinder via the modulator.

Here, the regulator comprises a housing having a cylinder hole, a piston slidably disposed in the cylinder hole, and a hydraulic chamber formed between one end of the piston and the housing and communicating with the master cylinder. A pressure regulating chamber formed between the other end of the piston and the housing and capable of communicating with the wheel cylinder; a spring for urging the piston in a direction to increase the volume of the pressure regulating chamber; And a hydraulic pressure control valve selectively communicating the chamber with an auxiliary hydraulic pressure source or reservoir.

[0004]

However, in this device, the pressure receiving area received by the piston from the regulator hydraulic pressure in the pressure regulating chamber is equal to the pressure receiving area received by the piston from the master cylinder hydraulic pressure in the hydraulic pressure chamber. The regulator hydraulic pressure is always slightly lower than the master cylinder hydraulic pressure due to the balance of the applied forces. That is, the ratio of the regulator hydraulic pressure to the master cylinder hydraulic pressure is always constant, and this ratio cannot be changed. Therefore, even with the same brake pedal operation amount, the brake fluid pressure applied to the wheel cylinder cannot be changed according to, for example, the loaded state of the vehicle.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a vehicle hydraulic brake device having a mechanical regulator and capable of changing the ratio of the regulator hydraulic pressure to the master cylinder hydraulic pressure. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned technical problems, a vehicle hydraulic brake device according to the first aspect of the present invention comprises:
A wheel cylinder mounted on a vehicle wheel to apply a braking force to the wheel, a reservoir for storing brake fluid, and boosting the brake fluid in the reservoir according to an operation amount of a brake pedal to output a master cylinder fluid pressure. A master cylinder, an auxiliary hydraulic pressure source that boosts the brake fluid in the reservoir to a predetermined pressure and outputs power hydraulic pressure, and an output hydraulic pressure of the master cylinder that receives the output power hydraulic pressure of the auxiliary hydraulic pressure source. In a vehicle hydraulic brake device comprising a mechanical regulator capable of adjusting to a regulator hydraulic pressure according to the above and outputting to the wheel cylinder, the regulator may change a ratio of a regulator hydraulic pressure to a master cylinder hydraulic pressure. It is configured to be possible.

According to the first aspect of the invention, the ratio of the regulator hydraulic pressure to the master cylinder hydraulic pressure can be changed, and as a result, the brake hydraulic pressure supplied to the wheel cylinder can be changed even with the same brake pedal operation amount.

In the first aspect, as set forth in the second aspect, the regulator is slidably disposed in a housing having a stepped cylinder hole and in the stepped cylinder hole,
A stepped piston having a cross-sectional area at one end larger than a cross-sectional area at the other end, a hydraulic chamber formed between one end of the stepped piston and the housing, and communicating with the master cylinder; A pressure regulating chamber formed between the other end and the housing, the pressure regulating chamber being communicable with the wheel cylinder, and being disposed in the stepped cylinder hole, and interlocking with the stepped piston, moving the pressure regulating chamber into the auxiliary fluid. A hydraulic pressure control valve selectively communicating with a pressure source or the reservoir, and the stepped piston formed between the stepped portion of the stepped piston and the housing so as to be located between the hydraulic pressure chamber and the pressure regulating chamber. An annular chamber having a pressure receiving area equal to the difference between the pressure receiving area at one end of the pressure chamber and the pressure receiving area at the other end of the stepped piston from the pressure regulating chamber; Selectively communicates with the reservoir When composed of a first switching valve which,
preferable.

According to this configuration, between the stepped portion of the stepped piston and the housing, the pressure receiving pressure equal to the difference between the pressure receiving area at one end of the stepped piston received from the hydraulic pressure chamber and the pressure receiving area at the other end of the stepped piston is received. An annular chamber having an area was formed, and the annular chamber could be selectively communicated with a pressure regulating chamber or a reservoir by a switching valve. Therefore, if the annular chamber is communicated with the pressure regulating chamber by the switching valve, the pressure receiving area of the stepped piston from the pressure regulating chamber side becomes equal to the pressure receiving area from the hydraulic pressure chamber side. As a result, the regulator for the master cylinder hydraulic pressure The pressure ratio becomes a predetermined ratio (for example, 1: 1). On the other hand, if the annular chamber is connected to the reservoir by the switching valve, the pressure receiving area of the stepped piston from the pressure regulating chamber side becomes smaller than the pressure receiving area from the hydraulic pressure chamber side.
The ratio of the regulator pressure to the master cylinder hydraulic pressure becomes larger than the above-mentioned predetermined ratio. Thus, the ratio of the regulator pressure to the master cylinder hydraulic pressure can be changed.

According to a second aspect of the present invention, it is preferable that the hydraulic chamber of the regulator is connected to a master cylinder via a hydraulic path, and the pressure adjusting chamber of the regulator is connected to the wheel cylinder. . According to this configuration, the regulator hydraulic pressure corresponding to the master cylinder hydraulic pressure can be reliably supplied to the wheel cylinder, and the regulator and the auxiliary hydraulic pressure source can be isolated from the master cylinder.

According to a second or third aspect, as described in the fourth aspect, a loading state detecting means for detecting a loading state of the vehicle, and when the loading state of the vehicle is lighter than a predetermined state, adjusting the annular chamber. The first switching valve is driven to communicate with the pressure chamber, and when the loading state of the vehicle is heavier than a predetermined state, the first switching valve is configured to communicate the annular chamber with the reservoir.
It is preferable to further include control means for driving one switching valve. According to this configuration, when the loaded state of the vehicle is lighter than the predetermined state, the annular chamber communicates with the pressure adjustment chamber, and the ratio of the regulator pressure to the master cylinder hydraulic pressure becomes a predetermined ratio (for example, 1: 1). On the other hand, when the loaded state of the vehicle is heavier than the predetermined state, the annular chamber communicates with the reservoir, and the ratio of the regulator pressure to the master cylinder hydraulic pressure becomes larger than the predetermined ratio. The applied brake fluid pressure can be increased. Thus, the braking force applied to the wheels can be changed according to the loaded state of the vehicle.

According to a fourth aspect, as set forth in the fifth aspect, the master cylinder has two pressure chambers, one of the pressure chambers of the master cylinder is connected to a front wheel cylinder, and the other pressure chamber is connected to the pressure chamber. The front wheel cylinder is connected to one of the pressure chambers of the master cylinder and the front wheel cylinder, and is connected to one of the master cylinder and the pressure chamber of the regulator. It is preferable to further include a second switching valve that communicates with the first switching valve.

According to a fifth aspect of the present invention, when the loading state of the vehicle is lighter than a predetermined state, the control means controls the first switching so that the annular chamber communicates with the pressure regulating chamber. Driving the valve and driving the second switching valve to connect the front wheel cylinder to one of the pressure chambers of the master cylinder. When the loaded state of the vehicle is heavier than a predetermined state, the annular chamber is placed in the reservoir. It is preferable that the first switching valve is driven so as to communicate with the second switching valve and the second switching valve is driven so as to communicate the front wheel cylinder to the pressure regulating chamber of the regulator.

According to this configuration, when the loaded state of the vehicle is lighter than the predetermined state, the annular chamber communicates with the pressure regulating chamber, and the ratio of the regulator pressure to the master cylinder hydraulic pressure becomes a predetermined ratio (for example, 1: 1). The regulator hydraulic pressure is supplied to the rear wheel cylinder. At the same time, the front wheel cylinder communicates with one pressure chamber of the master cylinder, and the master cylinder hydraulic pressure is supplied to the front wheel cylinder. On the other hand, when the loaded state of the vehicle is heavier than the predetermined state, the annular chamber communicates with the reservoir, and the ratio of the regulator pressure to the master cylinder hydraulic pressure becomes larger than the predetermined ratio, and this regulator hydraulic pressure is applied to the rear wheel cylinder. Supplied. At the same time, the front wheel cylinder communicates with the pressure regulating chamber of the regulator, and a high ratio of regulator fluid pressure is also supplied to the front wheel cylinder. Thus, the wheels to which the regulator hydraulic pressure is applied can be changed according to the loaded state of the vehicle.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a hydraulic brake system according to the present embodiment, in which a master cylinder 1 includes a negative pressure type booster 2.
Are connected to the brake pedal 3 and to the master reservoir 4. The master cylinder 1 is a dandem master cylinder in which two pressure chambers 1 a and 1 b are formed, and the brake fluid stored in the master reservoir 4 is supplied to the pressure chamber 1 according to the operation amount of the brake pedal 3.
Pressure is applied at a and 1b to output the master cylinder hydraulic pressure.
One of the pressure chambers 1a of the master cylinder 1 is connected to wheels FL, F in front of the vehicle via normally open type on-off valves PC1, PC2, respectively.
R wheel cylinders Wfl, Wfr. The on-off valves PC1 and PC2 have check valves CV1 and CV that allow only the flow of the brake fluid to the master cylinder 1 side.
2 are provided in parallel. The front wheel cylinders Wfl and Wfr are normally closed type on-off valves PC.
3. Connected to the master reservoir 4 via the PC 4.

The other pressure chamber 1b of the master cylinder 1
It is connected to the mechanical regulator 5 via a hydraulic path P1. The regulator 5 is connected to an auxiliary hydraulic pressure source 6 for generating power hydraulic pressure and the master reservoir 4, receives the output power hydraulic pressure of the auxiliary hydraulic pressure source 6, and responds to the output hydraulic pressure of the pressure chamber 1 b of the master cylinder 1. The pressure is adjusted to the regulator hydraulic pressure, and a specific configuration thereof will be described later. The auxiliary hydraulic pressure source 6 includes a motor-driven hydraulic pump 61, an accumulator 62, a check valve 63, and a relief valve 64. The hydraulic pump 61 sucks and pressurizes the brake fluid in the master reservoir 4 and discharges it to the accumulator 62. The accumulator 62 stores the boosted brake fluid by the hydraulic pump 61 and outputs power fluid pressure to the regulator 5. The check valve 63 is disposed between the hydraulic pump 61 and the accumulator 63, and blocks the flow of the brake fluid to the hydraulic pump. The relief valve 64 releases the accumulated brake fluid in the accumulator 62 to the master reservoir 4 when the fluid pressure in the accumulator 62 exceeds a predetermined upper limit.

The regulators 5 each include a normally-open type on-off valve P
C5 and PC6 are connected to wheel cylinders Wrl and Wrr of wheels RL and RR at the rear of the vehicle. Check valves CV3 and CV4 that allow only the flow of the brake fluid to the master cylinder 1 are provided in parallel with the on-off valves PC5 and PC6, respectively. The rear wheel cylinders Wrl and Wrr are normally closed on-off valves PC7 and PC8, respectively.
Is connected to the master reservoir 4 via the. here,
The communication between the rear wheel cylinders Wrl and Wrr with the pressure chamber 1b of the master cylinder 1 is always interrupted.
The on-off valves PC1 to PC8 adjust the brake fluid pressure of each wheel cylinder in accordance with a command from the electronic control unit 7, and constitute a modulator.

The housing 51 of the regulator 5 has an input port 51b, an output port 51c, a master port 51
d, a drain port 51e, a pressure increasing port 51f, a pressure reducing port 51g, and a switching port 51h. The input port 51b communicates with the accumulator 62 of the auxiliary hydraulic pressure source 6, and the output port 51c is connected to the rear wheel cylinders Wrl, Wrr via on-off valves PC5, PC6. The master port 51d communicates with the pressure chamber 1b of the master cylinder 1 via the hydraulic passage P1, and the drain port 51e
Communicates with the master reservoir 4. Booster port 51f
Communicates with the input port 51b, and the pressure reducing port 51g communicates with the drain port 51e. The switching port 51h can selectively communicate with the output port 51c or the pressure reducing port 51g.

Between the pressure chamber 1a of the master cylinder 1 and the front wheel modulators PC1 to PC4, an electromagnetic switching valve SV1 having three ports and two positions is provided. This switching valve SV1
Selectively connects the modulators PC1 to PC4 to the pressure chamber 1a of the master cylinder 1 or the output port 51c of the regulator 5. That is, the switching valve SV1 can be switched between an inoperative position where the modulators PC1 to PC4 are connected to the pressure chamber 1a of the master cylinder 1 and an active position where the modulators PC1 to PC4 are connected to the output port 51c of the regulator 5. Between the output port 51c of the regulator 5 and the rear wheel modulators PC5 to PC8, an electromagnetic switching valve SV2 at a 3 port 2 position is disposed. The switching valve SV2 selectively connects the modulators PC5 to PC8 to the output port 51c or the pressure increasing port 51f of the regulator 5 (that is, the auxiliary hydraulic pressure source 6). That is, the switching valve SV2
Can be switched between an inoperative position where the modulators PC5 to PC8 are connected to the output port 51c of the regulator 5 and an active position where the modulators PC5 to PC8 are connected to the pressure increasing port 51f of the regulator 5.

Between the output port 51c and the pressure reducing port 51g of the regulator 5 and the switching port 51h, a 3-port 2-position electromagnetic switching valve SV3 is provided. The switching valve SV3 selectively connects the switching port 51h to the output port 51c or the pressure reducing port 51g. That is, the switching valve SV3 is connected to the inactive position where the switching port 51h communicates with the output port 51c and the switching port 51h is connected to the pressure reducing port 51.
It can be switched to an operating position communicating with g.

A specific configuration of the regulator 5 of FIG. 1 will be described with reference to FIG.

The housing 51 has a stepped cylinder hole 51.
In the stepped cylinder hole 51a, a stepped piston 52 having a diameter (cross-sectional area) on one side larger than a diameter (cross-sectional area) on the other side is slidably disposed. Stepped piston 5
The master port 5 is provided between the large-diameter end of
A hydraulic pressure chamber 52 a communicating with the housing 51 is formed between the small-diameter end of the stepped piston 52 and the housing 51.
A pressure regulation chamber 52b communicating with 1c is formed. The pressure regulating chamber 520b has a smaller diameter than the hydraulic chamber 52a, and a pressure receiving area (ie, a sectional area of the small diameter end of the stepped piston 52) Srg in which the small diameter end of the stepped piston 52 receives from the regulator hydraulic pressure of the pressure regulating chamber 520b. Is smaller than the pressure receiving area (ie, the cross-sectional area of the large-diameter end of the stepped piston 52) Smc at which the large-diameter end of the stepped piston 52 receives from the master cylinder pressure in the hydraulic chamber 52a. The pressure adjustment piston 52 has a drain port 51
e and a communication passage 52c communicating with the pressure reducing port 51g are formed, and also communicate with the pressure regulating chamber 52b when the brake pedal 3 is not operated.

Step portion of stepped piston 52 and housing 5
An annular chamber 52e is formed between the fluid pressure chambers 52a and the pressure regulating chamber 52b, and communicates with the switching port 51h. The annular chamber 52e has a pressure receiving area (cross-sectional area of the large diameter end of the stepped piston 62) Smc received by the large diameter end of the stepped piston 52 from the hydraulic pressure chamber 52a and a pressure adjustment chamber 52b formed by the small diameter end of the stepped piston 52. From the pressure receiving area (cross-sectional area of the small-diameter end of the stepped piston 52) Srg.

A seal ring 52f is provided between the pressure regulating chamber 52d and the annular chamber 52e to ensure the sealing between them. The annular chamber 52e and the drain port 51e
A seal ring 52g is also provided between them to ensure the sealing between them. Drain port 51e and hydraulic chamber 5
A cup-shaped seal member 52h is provided between 2a to ensure the sealing between them. The pressure adjusting piston 52 is moved in the direction of increasing the volume of the pressure adjusting chamber 52b.
May be provided.

A cylinder member 54 having an isolation portion 541 for dividing the two holes 54a and 54b is fixed to the left end side of the cylinder hole 51a in the figure. The hole 54a is in the pressure regulating chamber 5
The valve body 55 is slidably disposed in the hole 54a. A ball 55a is fixed to an end of the valve body 55 on the pressure adjusting chamber 52b side, and the ball 55a is detachable from a valve seat 52d formed on an end of the pressure adjusting piston 52 on the pressure adjusting chamber 52b side. . The ball 55a is seated on the valve seat 52d when the pressure adjustment piston 52 slides by a predetermined distance in a direction to decrease the volume of the pressure adjustment chamber 52b.
The ball 55a and the valve seat 52d constitute a pressure reducing valve.
The communication between the pressure regulation chamber 52b and the communication passage 52c is made or interrupted, and the fluid pressure (regulator fluid pressure) in the pressure regulation chamber 52b is reduced.
The valve body 55 is urged toward the valve seat 52d by a spring 55b. A small-diameter projection 55c is integrally provided at the end of the valve body 55 opposite to the pressure regulation chamber 52b.

A ball-shaped valve body 56 is movably disposed in the hole 54b of the cylinder member 54, and is detachable from a valve seat 541a formed in the isolation portion 541. The valve body 56 is urged toward the valve seat 541a by a spring 56a, and is normally pressed and seated on the valve seat 541a. When the valve body 55 slides leftward in the figure, the valve body 56
Is pushed by the projection 55c of the valve body 55, and the valve seat 541a is
Break away from The cylinder member 54 has an input port 54
A communication passage 54c communicating with b is formed. The valve body 56, the valve seat 541a, and the spring 56a constitute a pressure increasing valve, and communicate with or block the pressure regulating chamber 52b and the communication passage 54c in cooperation with the above-described pressure reducing valve. Increase the pressure (regulator fluid pressure). The hole 54b is closed by a plug 57, and the right end opening of the housing 51 in the figure is closed by a nut 58.

Returning to FIG. 1, the switching valves SV1 to SV3 and the modulators PC1 to PC8 are electrically connected to the electronic control unit 7. The electronic control unit 7 is electrically connected to a loading state sensor (for example, a load sensor) 8 for detecting the loading state of the vehicle, and is configured to input the loading state of the vehicle. The electronic control unit 7 controls the switching valves SV1 and SV2 according to the loaded state of the vehicle. Specifically, when the loaded state of the vehicle is lighter than the predetermined state, the switching valves SV1 and SV3 are set to the inoperative positions shown in FIG. That is, the front wheel cylinders Wfl and Wfr communicate with the pressure chamber 1a of the master cylinder 1 and the annular chamber 52e.
(Switching port 51h) is in the pressure regulating chamber 52b (output port 51).
Connect to c). On the other hand, when the loaded state of the vehicle is heavier than the predetermined state, the switching valves SV1 and SV3 are switched to the operating positions. That is, the front wheel cylinders Wfl and Wfr communicate with the pressure regulating chamber 52b of the regulator 5, and the annular chamber 52e (switching port 51h) communicates with the master reservoir 4 (pressure reducing port 51g).

The electronic control unit 7 also controls the modulators PC1 to PC3 in response to detection signals from wheel speed sensors (not shown).
The PC 8 is controlled to perform anti-skid control. Further, the switching valve SV2 is switched to the operating position, the auxiliary hydraulic pressure source 6 is connected to the modulators PC1 to PC8, and brake pedals such as traction control, vehicle side skid suppression control (oversteer suppression control, understeer suppression control), automatic brake control, etc. Automatic control and the like unrelated to the operation 3 are executed.

The operation of the hydraulic brake device configured as described above will be described.

When the driver operates the brake pedal 3,
The output hydraulic pressure of the master cylinder 1 is switched from the pressure chamber 1a to the switching valve S.
It is supplied to the front wheel cylinders Wfl, Wfr via V1 and the opening / closing valves PC1, PC2, and braking force is applied to the front wheels FL, FR. At the same time, master cylinder 1
Is output from the pressure chamber 1b to the regulator 5 via the hydraulic pressure path P1, and the regulator 5 adjusts the power hydraulic pressure of the auxiliary hydraulic pressure source 6 to the regulator hydraulic pressure according to the master cylinder hydraulic pressure. You. This regulator fluid pressure is
It is supplied to the rear wheel cylinders Wrl and Wrr via the on-off valves PC5 and PC6, and braking force is applied to the rear wheels RL and RR. At this time, the rear wheel cylinder Wr
The output hydraulic pressure of the pressure chamber 1b of the master cylinder 1 is not applied to 1, Wrr.

When the loaded state of the vehicle is lighter than the predetermined state during the normal braking, the switching valve SV3 is maintained at the inoperative position shown in FIG.
2e communicates with the pressure regulation chamber 52b. Here, the pressure regulation chamber 52b
Assuming that the regulator pressure of the hydraulic pressure chamber 52a is Prmc and the master cylinder hydraulic pressure of the hydraulic chamber 52a is Pmc, the balance equation of the force of the pressure adjustment piston 520 is Prg · Srg + Prg (Smc−Sr
g) = Pmc · Smc. Prg = Pm
c. That is, the ratio of the master cylinder hydraulic pressure to the regulator hydraulic pressure becomes 1: 1 and the regulator hydraulic pressure equal to the master cylinder hydraulic pressure becomes equal to the rear wheel cylinder Wrl,
Wrr. At the same time, the switching valve SV1 is also maintained at the non-operating position shown in FIG. 1, the front wheel cylinders Wfl and Wfr communicate with the pressure chamber 1a of the master cylinder 1, and the master cylinder hydraulic pressure decreases.
fl, Wfr.

When the loaded state of the vehicle becomes heavier than the predetermined state, the electronic control unit 7 switches the switching valve SV3 to the non-operating position, and the annular chamber 52e communicates with the master reservoir 4. Here, the balance equation of the force of the pressure adjusting piston 52 is Prg · Srg + 0 · (Smc−Srg) = Pmc
Smc, and Prg = Pmc (Smc /
Srg). Since Smc> Srg, Prg>
Prg, and the ratio of the regulator hydraulic pressure to the master cylinder hydraulic pressure increases. As a result, the regulator fluid pressure higher than the master cylinder fluid pressure becomes the rear wheel cylinder Wr.
1, Wrr. At the same time, the switching valve SV1
Is also switched to the operating position, and the front wheel cylinder Wf
1 and Wfr also communicate with the pressure regulating chamber 52b of the regulator 50, and the regulator hydraulic pressure is reduced to the front wheel cylinder Wf.
1, Wfr. In this way, a high braking force can be applied to all wheels at the time of stacking, and the braking distance can be shortened. The ratio of the regulator hydraulic pressure to the master cylinder hydraulic pressure can be adjusted by changing the ratio of Smc and Srg.

On the other hand, when the driver releases the brake pedal 3, the pressure chambers 1a and 1b of the master cylinder 1 are depressurized, so that the brake fluid pressure of the front wheel cylinders Wfl and Wfr passes through the on-off valves PC1 and PC2, respectively. Pressure chamber 1
a (and thus the master reservoir 4), and the brake fluid pressures of the rear wheel cylinders Wrl and Wrr are returned to the master reservoir 4 via the on-off valves PC5 and PC6 and the regulator 5, respectively.

When one of the wheels (hereinafter referred to as the left rear wheel RL) has a tendency to lock, the on-off valves PC5 and PC7 are controlled to perform anti-skid control. Specifically, when the selected hydraulic pressure mode of the electronic control unit 7 is the pressure reduction mode, the on-off valve PC5 is switched to the closed position and the on-off valve PC7 is switched to the open position from the state of FIG. The pressure is discharged to the master reservoir 4 and reduced. In the holding mode, the on-off valve PC5 is switched to the closed position from the state shown in FIG. 1, and the brake fluid pressure of the wheel cylinder Wrl is held. In the case of the pressure increasing mode, the regulator hydraulic pressure is supplied to the wheel cylinder Wrl to increase the pressure while maintaining the state of FIG.

When performing automatic control on the front wheels, the electronic control unit 7 switches the switching valves SV1 and SV2 to the operating position, and the power hydraulic pressure of the auxiliary hydraulic pressure source 6 is switched to the switching valves SV2 and SV2.
It is supplied to front wheel cylinders Wfl, Wfr via SV1 and on-off valve PC1 or PC2. Thereafter, the brake fluid pressure of the front wheel cylinders Wfl, Wfr is adjusted to a desired value by the front wheel modulators PC1 to PC4.

When automatic control is to be performed on the rear wheels, the electronic control unit 7 switches the SV2 to the operating position, and the power hydraulic pressure of the auxiliary hydraulic pressure source 6 changes the switching valve SV2 and the on-off valve PC5 or PC6. Via rear wheel cylinder Wr
1, Wrr. Thereafter, rear wheel modulators PC5 to PC8 are used to control rear wheel cylinders Wrl and Wrl.
The brake fluid pressure of rr is adjusted to a desired value.

In the present embodiment, the switching valves SV1 and SV3 are controlled according to the loaded state of the vehicle. However, in addition to this control, the device of the present invention can be applied to brake assist control. That is, a pressure sensor for detecting the output hydraulic pressure of the master cylinder 1 is provided, and the switching valves SV1 and SV3 are driven according to the detection result of the pressure sensor. Specifically, when the brake assist is not controlled, the switching valves SV1 and SV3 are set to the state shown in FIG. 1, the master cylinder hydraulic pressure is supplied to the front wheel cylinders Wfl and Wfr, and the regulator hydraulic pressure is equal to the master cylinder hydraulic pressure. Is supplied to the rear wheel cylinders Wrl and Wrr. On the other hand, when the master cylinder hydraulic pressure is equal to or higher than a predetermined value and the increase rate is equal to or higher than the predetermined ratio, the brake assist control is started. At this time, the switching valves SV1 and SV3 are switched to the operating positions,
A regulator fluid pressure higher than the master cylinder fluid pressure is supplied to all wheel cylinders Wfl, Wfr, Wrl, Wrr, and a high braking force is secured.

In this embodiment, the example in which the regulator 5 is provided outside the master cylinder 1 has been described.
The present invention is also applicable to the one built in the master cylinder 1.

[0040]

According to the present invention, the ratio of the regulator hydraulic pressure to the master cylinder hydraulic pressure can be changed. As a result, the brake hydraulic pressure supplied to the wheel cylinder can be changed even with the same brake pedal operation amount.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a vehicle hydraulic brake device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the regulator of FIG.

[Explanation of symbols]

 FL, FR, RL, RR Wheels Wfl, Wfr, Wrl, Wrr Wheel cylinder 1 Master cylinder 1a, 1b Pressure chamber 3 Brake pedal 4 Master reservoir (reservoir) P1 Hydraulic path 5 Regulator 6 Auxiliary hydraulic pressure source 51 Housing 51a Stepped Cylinder hole 52 Stepped pressure adjusting piston (stepped piston) 52a Hydraulic pressure chamber 52b Pressure adjusting chamber 55 Valve element (hydraulic pressure control valve) 52d Valve seat (hydraulic pressure control valve) 56 Valve element (hydraulic pressure control valve) 541a Valve Seat (hydraulic pressure control valve) 56a Spring (hydraulic pressure control valve) 52e Annular chamber SV2 Switching valve (first switching valve) 8 Loading state sensor (loading state detecting means) 7 Electronic control device (control means) SV1 switching valve (first 2 switching valve)

Claims (6)

[Claims] 1. A wheel cylinder mounted on a wheel of a vehicle for applying a braking force to the wheel, a reservoir for storing a brake fluid, and a master cylinder for increasing the brake fluid in the reservoir in accordance with an operation amount of a brake pedal. A master cylinder that outputs hydraulic pressure, an auxiliary hydraulic pressure source that boosts the brake fluid in the reservoir to a predetermined pressure and outputs power hydraulic pressure, and an output power hydraulic pressure of the auxiliary hydraulic pressure source that inputs the master A hydraulic brake device for a vehicle, comprising: a mechanical regulator capable of adjusting a regulator hydraulic pressure in accordance with an output hydraulic pressure of a cylinder, and capable of outputting the output to the wheel cylinder. A hydraulic brake device for a vehicle configured to be able to change the ratio. 2. The regulator according to claim 1, wherein the regulator has a housing having a stepped cylinder hole, and is slidably disposed in the stepped cylinder hole, and a cross-sectional area of one end is larger than a cross-sectional area of the other end. A stepped piston, a hydraulic chamber formed between one end of the stepped piston and the housing and communicating with the master cylinder, and a hydraulic chamber formed between the other end of the stepped piston and the housing, A pressure regulating chamber communicable with a wheel cylinder; and a hydraulic pressure disposed in the stepped cylinder hole and selectively communicating the pressure regulating chamber with the auxiliary hydraulic pressure source or the reservoir in conjunction with the stepped piston. A control valve, formed between the step portion of the stepped piston and the housing so as to be located between the hydraulic pressure chamber and the pressure regulation chamber, one end of the stepped piston receives a pressure receiving area from the hydraulic pressure chamber, and Stepped Pi An annular chamber having a pressure receiving area equal to a difference in pressure receiving area at the other end of the ton from the pressure regulating chamber; and a first switching valve for selectively communicating the annular chamber with the pressure regulating chamber or the reservoir. Hydraulic brake device for vehicles. 3. The vehicle hydraulic pressure according to claim 2, wherein a hydraulic chamber of the regulator is connected to the master cylinder via a hydraulic path, and a pressure adjusting chamber of the regulator is connected to the wheel cylinder. Brake device. 4. The load state detecting means for detecting a load state of a vehicle according to claim 2 or 3, wherein when the load state of the vehicle is lighter than a predetermined state, the annular chamber communicates with the pressure regulating chamber. Driving the first switching valve, when the loading state of the vehicle is heavier than a predetermined state,
Control means for driving the first switching valve so that the annular chamber communicates with the reservoir. 5. The master cylinder according to claim 4, wherein the master cylinder has two pressure chambers, one pressure chamber of the master cylinder is connected to a front wheel cylinder, and the other pressure chamber is connected to a hydraulic chamber of the regulator. A second pressure chamber connected to one pressure chamber of the master cylinder and the front wheel cylinder for selectively communicating the front wheel cylinder to one pressure chamber of the master cylinder or a pressure regulation chamber of the regulator. A hydraulic brake device for a vehicle further comprising a switching valve. 6. The control device according to claim 5, wherein, when the loaded state of the vehicle is lighter than a predetermined state, the control means drives the first switching valve so that the annular chamber communicates with the pressure regulating chamber, and The second switching valve is driven to connect a front wheel cylinder to one of the pressure chambers of the master cylinder, and when the loaded state of the vehicle is heavier than a predetermined state, the second switching valve is connected to connect the annular chamber to the reservoir. (1) A vehicle hydraulic brake device configured to drive a second switching valve so as to drive a switching valve and connect the front wheel cylinder to a pressure regulating chamber of the regulator.