JPH0639648U - Vehicle hydraulic brake control device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a hydraulic brake control device for a vehicle, which can quickly perform a drive slip even when a standard master cylinder is used or even in cold air. [Structure] The piston of the valve drive device 82 in which the hydraulic pressure generator 20 is arranged between the master cylinder 1 and the discharge side of the hydraulic pump 33, and the hydraulic pressure generator 20 is driven by receiving hydraulic pressure from the power steering pump system PSP. Drive rod portion 84
By the forward movement of a, the piston 61 in the hydraulic pressure generator 20 is moved, and the hydraulic pressure generated thereby is moved to the drive wheels RL, RR.
The braking force is rapidly increased by adding to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle hydraulic brake control device.

[0002]

[Prior art and its problems]

 As a device of this type, a hydraulic pressure control valve for performing brake slip control and drive slip control of a wheel and provided between a master cylinder and a wheel brake device for controlling brake hydraulic pressure of the wheel brake device, When the brake fluid pressure is reduced by controlling the pressure control valve, the brake fluid discharged from the wheel brake device via the fluid pressure control valve is pressurized to connect the master cylinder and the fluid pressure control valve. A hydraulic pump that can be supplied to the hydraulic fluid supply pipeline, and is disposed between the discharge side of the hydraulic pump and the master cylinder, and is normally in communication, but during drive slip control the master cylinder Is disposed between the master cylinder side and the suction side of the hydraulic pump, and is normally in the cutoff state, but the drive slip control is performed. When the vehicle hydraulic 圧Bu rake controller having a second valve means which can be switched to the communicating state is known.

When the above device performs the drive slip control, the first valve means is in the shut-off state, the second valve means is in the communication state, and the hydraulic pump is started to drive the brake fluid from the master cylinder. The brake is applied by the pump suctioning through the second valve means and supplying the pressure fluid to the wheel cylinders of the drive wheels through the fluid pressure control valve. The master cylinder has a bore diameter of 10 mm. Because the pressure fluid is supplied to the wheel cylinder side through the wheel cylinder, the rate of increase in the braking force of the wheel cylinder is small, and the viscosity of the brake fluid becomes high especially in low temperature areas or cold air. The liquid flow of is reduced to reduce the speed at which the braking force rises. In this case, drive slip control in an emergency cannot be performed correspondingly, which may be extremely dangerous.

In order to deal with this, a design change in which the bore diameter of the master cylinder is increased to 12 mm, for example, is conceivable. However, such modification of the standard master cylinder increases the cost.

On the other hand, in Japanese Unexamined Patent Publication No. 63-90468, as shown in FIG. 5, cylinder chambers 132 and 133 are defined on both sides of the built-in piston 121, the left end of which is the auxiliary / main cylinder 114. It is in contact with the inner piston 115. Normally, since the solenoid valve 137 is closed in the cylinder chamber 132, a certain hydraulic pressure is applied by the hydraulic pressure of the low pressure pump 139. Therefore, the right end portion of the built-in piston 121 is located on the bottom wall surface of the main body 24. , And the coil spring 123 is in compression.

When the ASR control is started, the solenoid valve 137 is switched and the cylinder chamber 32 and the reservoir 35 are brought into communication with each other, so that the pressure liquid from the cylinder chamber 132 is returned to the reservoir 135. As a result, the piston body 120 of the built-in piston 121 is moved leftward by the spring force of the coil spring 123, whereby the piston 115 in the auxiliary / main cylinder 114 is also moved leftward and the central valve 108. By switching between the master cylinder M side and the wheel cylinder H side and reducing the volume of the cylinder 113 chamber in the auxiliary / main cylinder 114 to generate hydraulic pressure in the wheel cylinder W. This brakes the drive wheels. When the ASR control ends, the solenoid valve 137 is switched to the shut-off position, the hydraulic pump 139 is driven, and hydraulic pressure is applied to the cylinder chamber 132 on the left side of the built-in piston 121. The piston body 120 moves to the right against the force and returns to the initial state. The piston 115 in the auxiliary / main cylinder 114 is operated by a hydraulic pump (not shown) in the anti-skid device Q before hydraulic pressure is applied to the cylinder chamber 132 on the left side of the built-in piston 121 from the low pressure pump 39. It is moved to the right by receiving the discharge pressure force of and is loaded, but as described above, the hydraulic pressure from the low pressure pump 139 is applied to the left cylinder chamber 132 of the spring built-in piston 121. By doing so, the load due to the hydraulic pressure from the anti-skid control device Q is released.

That is, in the above publication, the brake is applied by the spring force of the relatively strong coil spring 123 arranged in the cylinder chamber 133 of the spring-incorporated piston 121, so that the low-pressure pump 139 is in the initial state. And, at the end of the ASR control, the pressure liquid is added to the cylinder chamber 132, so that the coil spring 123 is only driven to apply the preload.

As described above, since the brake fluid is not supplied from the master cylinder M side to the wheel cylinder W during the ASR control, the small bore diameter of the master cylinder as described above does not occur during the ASR control. Although not relevant, it is the spring force of the strong spring 123 of the spring built-in piston 121 that provides the braking force, and as is clear from the figure, the assembly of such a device is very difficult, Furthermore, the weight is increased.

[0009]

[Problems to be solved by the device]

 The present invention has been made in view of the above problems, and provides a hydraulic brake control device for a vehicle that can perform drive slip control quickly with a simple structure even when the conventional master cylinder is applied as it is or even in cold air. The purpose is to do.

[0010]

[Means for solving problems]

 The above object is to perform a brake slip control and a drive slip control for a wheel and to provide a brake pressure control valve that is provided between a master cylinder and a wheel brake device and controls a brake fluid pressure of the wheel brake device. When the brake fluid pressure is reduced by the control of the pressure control valve, the brake fluid discharged from the wheel brake device through the fluid pressure control valve is pressurized to connect the master cylinder and the fluid pressure control valve. In a vehicle hydraulic brake control device including a hydraulic pump capable of supplying to a liquid supply line, a first hydraulic chamber and a first hydraulic chamber in a main body are provided between a discharge side of the hydraulic pump and the master cylinder. At least a first piston defining an air chamber, and a passage connecting the master cylinder side and the discharge side of the hydraulic pump via the liquid chamber by moving the piston toward the liquid chamber A valve unit that can be shut off in the direction toward the star cylinder side, and after shutting off the valve unit, a hydraulic pressure generation device that generates hydraulic pressure by moving the piston toward the liquid chamber side; A second piston that defines a second air chamber and a second liquid chamber, and a second piston that is integrally formed with the second piston, and the second piston moves toward the first air chamber side of the hydraulic pressure generator. A valve drive device having a drive rod portion that pushes the first piston toward the first liquid chamber side by means of the above, and the second liquid chamber normally communicates with the hydraulic pressure release source side. This is achieved by a vehicle hydraulic brake control device, which is provided with valve means that can be switched so as to communicate with the hydraulic pressure supply source side during slip control.

Alternatively, a hydraulic pressure control valve, which is provided between the master cylinder and the wheel brake device and controls the brake hydraulic pressure of the wheel brake device, which performs the brake slip control and the drive slip control of the wheel, and the hydraulic pressure control valve. When the brake fluid pressure is reduced by the control of the control valve, the brake fluid discharged from the wheel brake device via the fluid pressure control valve is pressurized to connect the master cylinder and the fluid pressure control valve. In a vehicle hydraulic brake control device equipped with a hydraulic pump capable of supplying to a liquid supply pipeline, a liquid chamber and an air chamber are provided in the main body between the discharge side of the hydraulic pump and the master cylinder. At least the passage that connects the first piston that defines the first piston and the master cylinder side and the discharge side of the hydraulic pump via the liquid chamber by the movement of the piston toward the liquid chamber. A valve unit capable of shutting off with respect to the direction toward the cylinder side, and after shutting off the valve unit, a hydraulic pressure generation device that further generates hydraulic pressure by moving the piston to the liquid chamber side; A second piston that defines a first space and a second space, and a second piston formed integrally with the second piston, and the first piston is formed by moving the second piston toward the air chamber side of the hydraulic pressure generator. A valve drive device having a drive rod portion for moving the first space toward the liquid chamber side, and the first space is always connected to a negative pressure source, and the second space is normally connected to the negative pressure source side. However, it is achieved by a vehicle hydraulic brake control device, characterized in that valve means that is switched so as to communicate with the atmosphere during drive slip control is provided.

[0012]

[Action]

 When the drive slip control is started, the fluid chamber of the valve drive device is switched to the state in which it communicates with the fluid pressure supply source side, and the second piston is moved by the differential pressure between the fluid chamber and the air chamber to generate fluid pressure. After closing the valve part of the device, the volume is reduced and a braking force is generated. Since no brake fluid is supplied from the master cylinder, the braking force required for drive slip control can be quickly increased regardless of the bore diameter.

Alternatively, the second space of the valve drive device is switched to a state in which it communicates with the atmosphere side, the second piston is moved by the differential pressure between the first and second air chambers, and the valve portion of the hydraulic pressure generator is closed. After that, the braking force is generated due to the decrease in volume. Since no brake fluid is supplied from the master cylinder, the braking force required for drive slip control can be quickly increased regardless of the bore diameter.

[0014]

【Example】

 Hereinafter, a vehicle hydraulic brake control apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 also shows a piping system diagram of the vehicle hydraulic brake control device of the present embodiment, but the master cylinder with booster 1 is attached to the driver's seat of the vehicle even if not shown. The brake pedal 2 is coupled to the master cylinder portion 4 via the booster portion 3. These have a well-known structure, but a reservoir 5 for storing brake fluid is provided in the upper part thereof. The master cylinder portion 4 defines two hydraulic pressure generating chambers, one of which is connected to the pipe line 6 and the other of which is connected to the pipe line 7. The conduit 6 is connected to the front wheels FL and FR, and the conduit 7 is connected to the rear wheels RL and RR. That is, this embodiment employs the H pipe. The pipe line 6 is connected to the wheel cylinder of the left front wheel FL via a 2-port 2-position electromagnetic switching valve 8a and a pipe line 12, and the wheel cylinder is connected to a 2-port 2-position electromagnetic switching valve 8b. Similarly, the pipe line 13 separated from the pipe line 6 is connected to the wheel cylinder via the 2-port 2-position electromagnetic switching valve 9a for the right front wheel FR and the pipe line 14, and this wheel cylinder also has the 2-port 2 position. It is connected to the position electromagnetic switching valve 9b.

On the other hand, the pipe line 7 is connected to the rear wheel side. These are drive wheels in this embodiment, and the right rear wheel is connected via the hydraulic pressure generator 20 and the pipe line 21 according to the present invention. It is connected to its wheel cylinder via a two-port two-position solenoid operated directional control valve 28a for RR and a line 30, and this wheel cylinder is further connected to a two-port two-position solenoid operated directional control valve 28b. Similarly, a pipe line 27 separated from the pipe line 26 is connected to the wheel cylinder of the left rear wheel RL via a 2-port 2-position electromagnetic switching valve 29a and a pipe line 49. This wheel cylinder is further connected to a 2-port 2-position electromagnetic switching valve 29b.

The output port sides of the above-mentioned two-port two-position electromagnetic switching valves 8b, 9b, 28b, 29b are connected to reservoirs 42a, 42b connected to the suction side of the hydraulic pump 33 via pipe lines 44, 45. ing. These reservoirs 42a and 42b have a well-known structure and are composed of a relatively weak spring in the casing and a piston urged upward by the spring, thereby defining a reservoir chamber above the piston. . The hydraulic pump 33 has a well-known structure. Plungers 36a and 36b are provided on both sides of the eccentric drive part 34 so as to be slidable to the left and right, and a pair of hydraulic pressure generating chambers 37a and 37b are formed on the outside thereof. The check valves 41a and 41b are connected to the suction side of the reservoirs 42a and 42b from the hydraulic pressure generating chambers 37a and 37b to the forward direction. Check valves 38a and 38b, which have a forward direction from the chambers 37a and 37b side to the master cylinder side, are connected to the check valves 38a and 38b, and further through the dampers 39a and 39b and the throttles 40a and 40b. Is connected to the pipelines 6 and 21.

The details of the hydraulic pressure generator 20 and the valve driving device 82 for driving the hydraulic pressure generating device 20 are shown in FIG. 2. The valve driving device 82 is connected to the power steering pump system PSP. That is, this is a three-port two-position electromagnetic switching valve 51 connected to the valve drive device 82 via the conduit 52, and a reservoir 55 connected to the second port via the conduit 57, and It is composed of a hydraulic pump 54 connected to the suction side, and a relief valve 56 connected to the discharge port via conduits 53 and 59. The 3-port 2-position electromagnetic switching valve 51 is normally in the state shown in the figure, and when the ASR control is started, the pipelines 52 and 53 are communicated with each other and the pipelines 52 and 57 are shut off.

Next, the hydraulic pressure generator 20 will be described with reference to FIG. A piston 61 having a reduced diameter in the center is fitted to the cylindrical body 60 with seal rings 62 and 63 slidably fitted thereto, and a liquid chamber A and an air chamber B are provided on both sides thereof. Defined. A compression spring 64 is arranged in the liquid chamber A , and urges the piston 61 to the right in the figure to bring it to the position shown. Passages 61a and 61b are formed in the piston 61, which are always in communication with an input port 65 connected to the pipe line 7. Further, the output port 66 is formed so as to communicate with the liquid chamber A , which is connected to the above-mentioned pipe line 21. A valve seat 67, which is an O-ring, is fixed to the open end of the passage 61b of the piston 61, and a valve body 68 is opposed to this and seated oppositely by a spring 69. A head portion 70 faces the valve seat 67, and a rod portion 68 connecting the head portion 70 and the stopper portion 71 is slidably fitted in a hole 72 formed in the valve body 60. The spring 69 normally takes the position shown in the drawing, and the head 70 is separated from the valve seat 67.

The air chamber B is always in communication with the atmosphere via the through hole 81. In the valve drive device 82, a seal ring 85 is mounted in the main body 83, and a piston 84 having a T-shaped cross section is slidably fitted to define an air chamber C and a liquid chamber D. , Is biased to the right in the figure by the spring 87, and is normally in the position shown in the figure. The drive rod portion 84 a projects outward through a hole formed in the main body 83 sealed by a seal ring 86 and passes through a hole h formed in the hydraulic pressure generator 20. It is in contact with the piston 61 in 20.

Ports 88 and 100 are further formed in the main body 83, the port 100 communicates with the atmosphere, and the port 88 is connected to the above-mentioned PSP via the pipe line 52.

The embodiment of the present invention is configured as described above. Next, this operation will be described.

Now, the driver depresses the accelerator pedal to start traveling. At the same time, the power steering pump system PSP starts driving. That is, the hydraulic pump 54 is driven, which sucks the hydraulic fluid from the reservoir 55 and applies the hydraulic pressure to the first port of the switching valve 51. Although no pressure is applied to the relief valve 56, when a fluid pressure higher than a predetermined pressure is applied to the relief valve 56, the relief valve 56 is opened to return the pressure fluid to the reservoir 55 via the conduit 57.

A control unit (not shown) receives a signal from a wheel speed sensor provided on the drive wheels RL and RR, and when it is determined that a drive slip has occurred at a predetermined value or more, this generates a drive slip control signal for switching. The solenoid 51a of the valve 51 is excited to connect the conduits 52 and 53 to each other and disconnect the conduits 52 and 57. The motor 35 of the hydraulic pump 33 starts driving. The hydraulic pressure generator 20 normally takes the state shown in FIG. 2 and connects the master cylinder with booster 1 side and the pipeline 21 side to each other. However, since the driver has not stepped on the brake pedal now, No hydraulic pressure is generated in the master cylinder part 4 and no hydraulic pressure is applied to the hydraulic fluid supply pipes 6 and 7. However, as described above, the hydraulic pressure is supplied from the power steering pump system PSP. The hydraulic pressure of the pump 54 passes through the switching valve 51 and the pipe line 52, and the liquid chamber of the valve drive device 82.DIn addition, due to the differential pressure on both sides of the piston 84, the piston 84 moves to the left in the figure. Therefore, the piston 61 in the hydraulic pressure generator 20 is pushed leftward in the drawing, and the valve seat 67 formed on the right end surface of the piston 61 abuts on the head portion 70 of the valve body 68. Disconnect from the wheel cylinder side. After this, the liquid chamber A The liquid flow from the side to the conduit 7 side is blocked through the passages 61a and 61b, but the liquid flow from the master cylinder side is allowed. That is, the valve body 68 and the spring 69 constitute a check valve.

The volume of the liquid chamber A is reduced by the piston 61 seating the head 70 of the valve body 68 and the valve seat 67 and moving to the left. Therefore, hydraulic pressure is generated, the pipe 21 and the check valve 25 are opened, and the passages 26 and 27 are passed through the switching valves 28a and 29a, and the left and right rear wheels RL and RR, which are the drive wheels, are connected to the wheel cylinders. Apply hydraulic pressure and break them.

On the other hand, the hydraulic pump 33 starts driving at the same time as the ASR control is started, but it is idling because the brake fluid is not stored in the reservoirs 42a and 42b. Therefore, the ASR control is quickly performed to converge the drive slip to the optimum value or 0. However, according to the present embodiment, when it is determined that the control signal of the control unit contains too much brake. , An excitation signal is applied to the solenoids of the switching valves 28b, 29b to switch them to a cutoff state and a communication state, and the pressure fluid of the wheel cylinders of the rear wheels RL, RR is switched to these switching valves 28a, 29b, 28b, 29b. It is discharged to the reservoir 42b via the conduit 45. Therefore, the braking is reduced. The hydraulic fluid discharged to the reservoir 42 is immediately sucked by the hydraulic pump 33, supplied to the pipeline 21 side, and returned to the hydraulic chamber A side of the hydraulic pressure generator 20. At this time, the power steering pump system PSP continues to drive, but since the hydraulic pressure of the hydraulic pump 33 is higher than the discharge pressure of the hydraulic pump 54 of the system PSP, the piston 61 is not When the valve body 68 is moved to the right in FIG. 2 and is moved so as to be separated from the valve seat 67 side, the pressure liquid from the liquid chamber B passes through the pipe line 52 and the pipe line 53, and the relief valve It is added to 56, and when it exceeds a predetermined value, it is opened to pass the pipe 57 to release the hydraulic pressure to the reservoir 55.

By repeatedly increasing and decreasing the braking force as described above, it is possible to perform fine ASR control and quickly converge the drive slip to the optimum value or zero.

The drive slip (ASR control) has been described above. To briefly explain the ABS control, if the driver depresses the brake pedal 2 and the control unit is judged to be overloaded, the pipeline 6, 7. The brake is applied by the pressure fluid applied to the wheel cylinders of the wheels RL, RR, FL, FR via the passages 61a, 61b of the fluid pressure generator 20 and the switching valves 8a, 9a, 28a, 29a. However, since it was determined that this was overloaded, an excitation signal was applied to the switching valves 8a, 8b, 9a, 9b, 28a, 28b, 29a, 29b (for the sake of clarity, The wheels RL, RR, FL and FR are assumed to be in the same slip state at the same time.). The hydraulic fluid in the wheel cylinders of the wheels RL, RR, FL, FR passes through the switching valves 8b, 9b, 29b, 29b and the pipelines 44, 45, is discharged to the reservoirs 42a, 42b, and the brake is immediately released. These are immediately sucked by the hydraulic pump 33 and returned to the pressurized liquid supply pipe line connecting the master cylinder side and these switching valves. On the discharge side of the hydraulic pump 33, dampers 39a, 39b and throttles are provided. Since 40a and 40b are provided, the pedal kick reduction is returned to the master cylinder 4 with a minimum reduction, and the driver is not made to feel any discomfort.

Although the embodiment of the present invention is configured and operates as described above, it is not necessary to suck the brake fluid from the master cylinder portion 4 during the ASR control as is clear from the above description. Similarly, even if the bore diameter of the master cylinder portion 4 is as small as 10 mm, the drive slip control can be quickly performed regardless of this. In other words, it was necessary to make the bore diameter 12 mm or more in order to perform ASR control quickly, but 10 mm is a standard product, and there is no need to redesign separately to make this 12 mm, so equipment cost is reduced. Compared to this case, it can be greatly reduced. It should be noted that when the viscosity of the brake fluid increases in the cold air, the supply rate of the brake fluid from the master cylinder portion 4 may decrease, which can be dealt with.

Next, a second embodiment will be described. The parts corresponding to those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

According to the present embodiment, the port 88 of the valve drive device 82 is connected to the first port of the 3-port 2-position electromagnetic switching valve 90, and the second port is connected to the pipe line 101. The second port of the switching valve 90 is a negative pressure source 91, which is, for example, an engine intech manifold, is connected to this, and always supplies a negative pressure to the pipe 101. The third port communicates with the atmosphere, and when the solenoid 60a is excited, the atmosphere communicates with the conduit 89 and the conduits 89 and 101 are shut off.

The second embodiment of the present invention is constructed as described above, but when the ASR control is started, the solenoid 90a of the switching valve 90 is excited and is normally defined on both sides of the piston 84 as shown in the figure. Negative pressure is supplied to the vacant chambers C and D sides (see FIG. 2), but the atmosphere is now communicated with the second port of the switching valve 90 and the atmosphere, so that the atmosphere is connected to the pipe 89 and the port. Since the pressure is supplied to the vacant chamber D side through 88 and the negative pressure is supplied to the vacant chamber C side, the differential pressure on both sides of the piston 84 causes the piston 84 to move to the left in the figure. Therefore, the piston 61 in the hydraulic pressure generator 20 is pushed to the left in the drawing, and the valve seat 67 formed on the right end surface of the piston 61 contacts the head 70 of the valve body 68, so that the master cylinder side Disconnect from the wheel cylinder side. Hereinafter, the same operation as that of the first embodiment can be performed.

Although the respective embodiments of the present invention have been described above, needless to say, the present invention is not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above-described embodiment, the check valve is formed by the valve body 68, the spring 69 and the valve seat 67 in the hydraulic pressure generator, so that the brake pedal 2 is depressed during ASR control so that the master cylinder side can operate. Although it is possible to supply the brake fluid under pressure, this is not a check valve, but it may be possible to shut off both fluid flows from the master cylinder side to the wheel cylinder side and from the wheel cylinder side to the master cylinder side. . In this case, the structure of the valve body can be further simplified.

Further, in the above embodiments, the master cylinder with a booster has been described, but the invention can of course be applied to a normal tandem master cylinder without a booster or a single master cylinder. A commercially available single vacuum booster can be applied to the hydraulic pressure generator 20 and the valve drive device 82 'of the second embodiment.

[0036]

[Effect of device]

 As described above, according to the vehicle hydraulic brake control device of the present invention, even if the master cylinder has the same structure as the conventional one, even in cold air, the drive slip control can be performed without changing the structure. Can be done quickly.

[Brief description of drawings]

FIG. 1 is a piping system diagram of a vehicle hydraulic brake control device according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the device.

FIG. 3 is a piping system diagram of a vehicle hydraulic brake control device according to a second embodiment.

FIG. 4 is a piping system diagram of a conventional example.

[Explanation of symbols]

 20 hydraulic pressure generator 20 'hydraulic pressure generator 51 switching valve 82 valve drive device 82' valve drive device 90 switching valve

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[Procedure amendment]

[Submission date] July 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Scope of utility model registration request

[Correction method] Change

[Correction content]

[Scope of utility model registration request]

Claims (2)

[Scope of utility model registration request] 1. A hydraulic pressure control valve, which is provided between a master cylinder and a wheel brake device and which controls a brake slip and a drive slip of a wheel and controls a brake hydraulic pressure of the wheel brake device, and the hydraulic pressure. When the brake fluid pressure is reduced by the control of the control valve, the brake fluid discharged from the wheel brake device via the fluid pressure control valve is pressurized to connect the master cylinder and the fluid pressure control valve. In a vehicle hydraulic brake control device including a hydraulic pump capable of supplying to a supply pipeline, a first hydraulic chamber and a first air chamber are provided in a main body between a discharge side of the hydraulic pump and the master cylinder. A first piston that defines a chamber and a passage that connects the master cylinder side and the discharge side of the hydraulic pump via the liquid chamber by moving the piston toward the liquid chamber. A valve unit capable of shutting off with respect to the direction toward the binder side, and after shutting off the valve unit, a hydraulic pressure generation device that further generates hydraulic pressure by moving the piston toward the liquid chamber side; A second piston defining a second air chamber and a second liquid chamber; and a second piston formed integrally with the second piston.
A valve drive device having a drive rod portion for moving the first piston toward the first liquid chamber side by moving the piston toward the first air chamber side of the hydraulic pressure generation device; and the second liquid chamber. Is normally communicated with the hydraulic pressure release source side, but is provided with switchable valve means so as to be communicated with the hydraulic pressure supply source side during drive slip control. apparatus. 2. A hydraulic pressure control valve, which is provided between a master cylinder and a wheel brake device and which controls a brake slip and a drive slip of a wheel and controls a brake hydraulic pressure of the wheel brake device, and the hydraulic pressure. When the brake fluid pressure is reduced by the control of the control valve, the brake fluid discharged from the wheel brake device via the fluid pressure control valve is pressurized to connect the master cylinder and the fluid pressure control valve. In a vehicle hydraulic brake control device including a hydraulic pump capable of supplying to a supply pipeline, a liquid chamber and an air chamber are defined in a main body between a discharge side of the hydraulic pump and the master cylinder. At least the master cylinder side through a passage that connects the first piston that is formed and the master cylinder side and the discharge side of the hydraulic pump through the liquid chamber by the movement of the piston toward the liquid chamber side. A valve unit capable of shutting off with respect to the direction to the direction, and after shutting off the valve unit, a hydraulic pressure generator for generating hydraulic pressure by moving the piston toward the liquid chamber side; and a first space in the main body. And a second piston that defines a second space, and is integrally formed with the second piston, and the first piston is formed by moving the second piston toward the air chamber side of the hydraulic pressure generator.
A valve drive device having a drive rod portion for pushing a piston toward the liquid chamber side, the first space is always connected to a negative pressure source, and the second space is normally communicated with the negative pressure source side. However, the vehicle hydraulic brake control device is provided with valve means that is switched so as to communicate with the atmosphere during drive slip control.