JPH0218153A - Device for controlling fluid pressure brake for vehicle - Google Patents

Abstract

PURPOSE:To prevent the stroke of a brake pedal from being extended by letting a reservoir be composed of No.1 reservoir capable of storing brake fluid in advance, and of No.2 reservoir capable of storing brake fluid, and thereby providing a valve device for a pipe line between both of the reservoirs. CONSTITUTION:In a brake device in a X-type arrangement equipped with brake piping, No.1 fluid pressure generating chamber of a tandem master cylinder 1 is connected with the whole cylinder 11 of one driving front wheel 10 via a pipe line 5, a three port three position electromagnetic change-over valve 8 acting as No.1 valve device, and a pipe line 9 wherein the tandem master cylinder 1 is equipped with a cylinder main body 2 having reservoir 4 which stores brake fluid in the cylinder main body 2. In this case, the discharge port of the change-over valve 8 is connected with No.2 reservoir 15 via a pipe line 14 so that the reservoir chamber 20 of it is connected with the reservoir 4 via a pipe line 22, an interrupting valve device 23 acting as No.2 valve device and a pipe line 24. The interrupting valve 23 is controlled depending on the pressure of the pipe line 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic brake control device for a vehicle that controls braking slip and driving slip of wheels.

[Conventional technology]

As a wheel braking slip control device (slip prevention device), for example, in the device disclosed in Japanese Patent Application Laid-Open No. 134361/1982, a hydraulic pressure control valve is provided between a master cylinder and a wheel brake device. During pressure reduction control, the brake fluid from the wheel brake device is discharged into a reservoir via a hydraulic pressure control valve, and during pressure increase control again, the brake fluid discharged into the reservoir is pressurized by a hydraulic pump. The fluid is supplied between the hydraulic pressure control valve and the wheel brake device.

On the other hand, in recent years, wheel braking slip control devices have been developed to prevent excessive slippage of the drive wheels that occurs when the vehicle suddenly starts or accelerates.
7. There has also been an increasing need for a drive slip control device that suppresses slippage, facilitates the driver's driving operations, and improves starting/acceleration performance and handling stability.

For this reason, the present applicant has improved the device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 62-134361, for example, by using a reservoir for the master cylinder that also serves as a reservoir connected to the above-mentioned hydraulic pressure control valve, that is, during pressure reduction control. When pressurizing drive slip control, the discharge pressure fluid of the hydraulic pump is discharged to the master cylinder reservoir via a return line that bypasses the input side and output side of the hydraulic control valve. In order to prevent the oil from being discharged into the cylinder reservoir and making it impossible to pressurize the wheel brake equipment, it was proposed to provide a shutoff valve in the return pipe (Utility Application No. 63-54240).

[Problem to be solved by the invention]

However, in the above proposal, while the brake pedal is still being depressed, the amount of brake fluid that is directly discharged from the wheel brake system into the master cylinder reservoir during the braking slip control after the brake IJ knob control is completed is transferred to the master cylinder and fluid. Unless it is returned to the hydraulic pressure generation chamber side of the master cylinder via a conduit connecting it to the pressure control valve, the piston stroke of the master cylinder, or in other words, the brake pedal stroke, will be unnecessarily extended. For this reason, even after it is no longer necessary to control the brake fluid pressure of the wheel brake device, the hydraulic pump must be driven by the amount of discharged brake fluid to return it to the fluid pressure generation chamber, making the control that much more complicated. However, it is difficult to estimate the amount of brake fluid discharged. It is an object of the present invention to provide a hydraulic brake control device for a vehicle that can prevent wheel braking slip and driving slip without being inaccurate even if a fluid level switch is provided in the reservoir and the amount of discharged brake fluid is measured. aimed to.

[Means for solving problems]

The above purpose is to provide a hydraulic control valve that controls the brake fluid pressure of the wheel brake device in response to a command from a control unit that evaluates braking slip and/or driving slip of the wheel, and a hydraulic pressure control valve that controls the brake fluid pressure of the wheel brake device. When reducing brake fluid pressure, a reservoir for storing brake fluid discharged from the wheel brake device via the fluid pressure control valve, pressurizing the brake fluid in the reservoir, and connecting a master cylinder and the wheel brake device. In the hydraulic brake control device for a vehicle, the vehicle hydraulic brake control device includes a hydraulic pump capable of supplying fluid to a main pipe side of the reservoir, and a first valve device capable of cutting off fluid communication from the discharge side of the hydraulic pump to the master cylinder side. consists of a first reservoir that stores brake fluid in advance and a second reservoir that can store brake fluid, and a second valve device that can cut off fluid communication is provided in a conduit that connects both reservoirs. This is achieved by a hydraulic brake control device for a vehicle, characterized in that the second reservoir is connected to the hydraulic pressure control valve, and the suction side of the hydraulic pump is connected to the second reservoir.

[Function] The second valve device establishes a state in which the first reservoir and the second reservoir are in liquid communication during the drive slip control, and a state in which the first reservoir and the second reservoir are in fluid communication during the control slip control. Take a state where communication is cut off.

Therefore, during braking slip control, the brake fluid supplied from the master cylinder hydraulic pressure generation chamber to the wheel brake device is not discharged to the first reservoir, and the brake fluid discharged from the wheel brake device to the second reservoir is Since all of the hydraulic pressure can be returned to the master cylinder hydraulic pressure generation chamber, the master cylinder's piston stroke (brake pedal stroke) will not be unnecessarily extended, and during braking slip control, the first valve device is always connected to the discharge side of the hydraulic pump. Even if the fluid communication from the main cylinder to the master cylinder is cut off, all discharged brake fluid can be resupplied to the wheel brake system, so there is no need to further depress the brake pedal to replenish the fluid, again eliminating the need for brake pedal strokes. It won't last.

Control is simple because the first valve device can be kept in a state where fluid communication from the discharge side of the hydraulic pump to the master cylinder side is always cut off during brake control, slip control, and drive slip control.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, in which the vehicle is a front-wheel drive four-wheeled vehicle with X-brake piping. In the figure, the cylinder body (2) of the tandem master cylinder (1) is connected to a brake pedal (3), and when this pedal (3) is depressed, hydraulic pressure is generated in two hydraulic pressure generating chambers. There is. The cylinder body (2) also includes a reservoir (4) for storing brake fluid. The 10th hydraulic pressure generating chamber of the tandem master cylinder (1) is connected to a conduit (5) and a check valve device (6) as a first valve device.
), connected to the wheel cylinder of one of the driving front wheels via a pipe (7), a three-point, three-position electromagnetic switching valve (8) as a hydraulic pressure control valve, and a pipe (9). .

Pipe line 0 connected to the outlet of the switching valve (8) is connected to the reservoir. The reservoir (G) corresponds to the second reservoir of the present invention and has a known structure, and the piston (B) has a 7-cylinder (to) attached to the casing opening.
is biased by the spring wire and is slidably fitted. This piston (B) defines a pump air chamber a and a reservoir chamber (1), and this reservoir chamber wall is connected to the opening C+9 and the pipe of the shutoff valve device as the second valve device. via the reservoir (4) of the tandem master cylinder (first aspect of the present invention).
(equivalent to a reservoir).

The shutoff valve device @ has a pressure sensing section (23a) which is connected to a pressure sensing line G which is connected to the line (5).

The check valve device (6) assumes the B position in response to a drive signal supplied to the check valve device (6a) from a control unit (not shown). That is, when this current level is zero, the valve position is 9, and at this time, the pipes (5) and (7) are in communication with each other. Also, when the current level is 111, the B position is turned off, and at this time it functions as a check valve, with the forward direction being from the tandem master cylinder (1) side to the wheel cylinder side.

Further, the three-bottom, three-position switching valve (8) assumes positions P, C, D, or E depending on the level of current applied to its solenoid (8a) from a control unit (not shown). That is, when the level is zero, the pipes (7) and (9) are communicated with each other by 1° from the C position. In addition, in the case of ), move the D position to shut off the pipes (7) and (9), and
Both pipe line (9) and a- are cut off. Furthermore, when the current level is @1", move to E position, and at this time, the pipe (
7) and the pipe line (9) are cut off, but the pipe line (9) and the pipe line ◆ are made to communicate with each other. Note that a check valve ■ is connected in parallel to the switching valve (8). The forward direction is from the wheel cylinder equipment to the master cylinder side.

In addition, depending on whether the pressure applied to the pressure detection part (23m) of the shutoff valve device Q3ti exceeds a predetermined value, 9F or F
Take the position of iG. When the value is below a predetermined value, the F position and the (to) of the pipe are communicated. When the value exceeds a predetermined value, the G position and the bottom of the pipe are shut off.

Furthermore, the suction port of the hydraulic pump ■ is connected to the pipe line connecting the reservoir (g) and the shutoff valve device (c), and its discharge port connects the check valve device (6) and the switching valve (6). It is connected to the conduit (7). Further, the discharge port is also connected to the reservoir (to) side via the +79-7 valve device surface and the pipe line (2). That is, when the discharge hydraulic pressure of the hydraulic pump (2) exceeds a predetermined value, the relief valve device (2) opens, allowing the discharge port side of the hydraulic pump (2) to communicate with the reservoir (toward) side. Also,
The pipe θ is connected to the wheel cylinder of the driven rear wheel located at the diagonal position of the front wheel (10) via a switching valve and a pressure reducing proportional valve (both not shown) having the same configuration as the switching valve (8). The outlet of the switching valve for the rear wheel is connected to the pipe (b).That is, in the same way as the wheel cylinder of the front wheel (2), the wheel cylinder of the rear wheel of that system is also connected to the switching valve (not shown). ) is connected to the reservoir chamber (7) of the reservoir (c) at the relaxed position.

In addition, the other hydraulic pressure generating chamber of the master cylinder (2) is connected to a device having the same configuration as that of the above-mentioned one system via the pipe line (2), and is connected to the other driving front wheel and the other hydraulic pressure generating chamber located at a diagonal position thereof. Connected to the wheel cylinder of the driven rear wheel.

As described above, this embodiment employs a so-called 4-channel anti-skid control system in which switching valves (8) as hydraulic pressure control valves are provided for each of the four wheels.

The vehicle hydraulic brake system according to the embodiment of the present invention is constructed as described above, and its operation will be explained next.

First, the drive slip control action will be explained.

For example, assume that a sudden start causes drive slip in the front wheels. The control unit detects this via a sensor that detects the rotational speed of the wheel, and the check valve device (6) K
The solenoid part (6a) in the check valve device (6a) is energized.
) to position B. Although not shown, the hydraulic pump■
The motor that drives starts driving. This causes brake fluid to flow from the reservoir (4) of the tandem master cylinder (1) to the shutoff valve device c! 3 (the brake pedal (3) is not depressed, so it is in the F position), and the pressurized fluid is sucked into the hydraulic pump ■ and pressurized through the pipe (7) and the switching valve (8) in the C position. It is supplied to the wheel cylinder circle of the front wheel α1, which is the driving wheel. To make the explanation easier to understand, it is assumed that drive slip occurs equally in both front wheels and drive slip control is performed at the same time. This applies a braking force and leads the drive slip to decrease.

On the other hand, each switching valve (not shown) for both rear wheels is switched to the D position at the same time as the drive slip control starts, so that the brake is not applied to the rear wheel which is a driven wheel.

Furthermore, when the switching valve (8) assumes the D position, the braking force on the front wheels becomes constant, and when the switching valve (8) assumes the E position, the braking force is relaxed. At position E, the pressure fluid from the wheel cylinder C1υ passes through the pipe αΦ and is discharged to the reservoir (!9 (4), but is immediately sucked into the hydraulic pump ■ and supplied to the pipes (n). Since a relief valve device is provided, if the discharge pressure of the hydraulic pump (G) becomes abnormally high, the relief valve □□□ will take the relief position and the liquid pressure will flow through the pipe (2). is returned to the reservoir (c). Also, since the check valve device (6) is in position B, the discharge pressure fluid from the hydraulic pump ■ is not transmitted to the master cylinder (2) side. Therefore, drive slip control of wheel a0, which is the drive wheel, is performed.

Next, the anti-skid control effect will be explained.

At this time, the I/C is in the initial state, the brake pedal (3
), hydraulic pressure is generated in the pipe G, which is detected by the pressure detection part (23a) of the shutoff valve device [with]
The position can be switched. That is, tandem master cylinder (1
) and the second reservoir (4) side and the second reservoir (toward) side are placed in a disconnected state. Until the anti-skid control starts, the check valve device [6] is in the A position, and the switching valve (8) is also in the C position, so that the pressure fluid from the master cylinder (1) is routed through the pipe. (5), check valve device (6), pipe line (7), switching valve (8), pipe line (9) to wheel cylinder ση
supplied to Therefore, the brakes are applied.

When the control unit determines that the brake of wheel αQ should be released based on the signal from the wheel speed sensor, a current level "" is applied to the solenoid part (8a) of the switching valve (8).
A control signal of "1" is supplied. This allows the switching valve (8
) assumes the E position and the hydraulic pump ω also starts driving,
Pressure fluid from the wheel cylinder Qll flows through pipes (9) and (
(b) and is discharged into the reservoir (b).

At this time, since the shutoff valve device (c) is in the G position, it is not returned to the reservoir (4) of the tandem master cylinder (1).

The hydraulic pump (261) immediately pressurizes the brake fluid in the reservoir chamber (E) of the reservoir (G) and supplies it to the pipe line (7).

Also, at this time, when the anti-skid control starts, the check valve device (
Since the solenoid part (6a) of 6) is energized, it assumes the B position and functions as a check valve whose forward direction is from the tandem master cylinder side to the wheel cylinder side, so the hydraulic pump The hydraulic pressure in ■ is not applied to the master cylinder side. In other words, there is no kickback phenomenon. In addition, since the pipes (7) and (9) are in a blocked state, the discharge liquid pressure of the hydraulic pump becomes high, but when this rises above a predetermined value, the relief valve device α is activated to reduce this pressure. Leaf the liquid to the pipe (c) side. In other words, hydraulic pump ω → pipe (to) → reservoir) → pipe ■ → hydraulic pump ■
and brake fluid is circulated.

In addition, if it is determined that the control unit should keep the brake pressure constant, the solenoid part (8) of the switching valve (8)
The level of the current supplied to a) becomes "1". This causes the switching valve (8) to assume the D position. Therefore, the pipe (7
) and (9) and conduit (9) and C14 are placed in a disconnected state, and the brake is held constant. At this time, the hydraulic pump ■ is being driven continuously, but the check valve device (6) is in position B, so the tandem master cylinder (1)
It will not be supplied to the side. In addition, pressure fluid from the tandem master cylinder (1) side can be supplied to the wheel cylinder side, so when hydraulic pressure higher than the hydraulic pressure of the hydraulic pump ■ is transmitted from the master cylinder side, the pressure fluid from the tandem master cylinder side can be supplied to the wheel cylinder side. Brake fluid can also be supplied to the wheel cylinder αη. Furthermore, the anti-skid control for the other front wheel and both rear wheels is performed independently, similarly to the control for the front wheel αQ.

Although the present embodiment performs the above-mentioned operation, the control is much simpler than that of the prior art (particularly Utility Application No. 63-54240) for the following reasons.

In other words, in this embodiment, by switching the shutoff valve (■), the circuit is made open during drive slip control, and the circuit is closed during anti-skid control, and unlike the conventional technology, the circuit is made open during both drive slip control and anti-skid control. However, even after anti-skid control, the hydraulic pump must be driven to return the brake fluid discharged into the master cylinder's reservoir during anti-skid control to the master cylinder's hydraulic pressure generating chamber. There is no need for extra control such as whether the

Although FIG. 2 shows a second embodiment of the present invention, detailed explanation of the parts corresponding to FIG. 1 will be omitted.

That is, in this embodiment, the second check valve device section is connected to the pipe line 311 that connects the pipe line (9) connecting the switching valve (8) and the wheel cylinder circle to the discharge side of the hydraulic pump (2). ing. This has a pressure detection part (30a), and is designed to detect the hydraulic pressure in the pipe line 6z connecting the switching valve (8) and the reservoir chamber duct of the reservoir (G). In normal cases, the H position is the discharge side of the hydraulic pump ■ and the wheel cylinder side η.
However, when the hydraulic pressure in the pipe line 32 exceeds a predetermined value, the check valve device returns to its working position and functions as a check valve. That is, wheel cylinder α,
1) It functions as a check valve whose forward direction is the direction from 111 to the discharge side of the hydraulic pump (2).

Further, a check valve port is connected to a pipe line (b) connecting the discharge side of the hydraulic pump @ and the first check valve device (6). Between these check valves is a first check valve device (6
) side, that is, the direction toward the master cylinder side is defined as the forward direction. Further, when the second check valve device [6] is switched to the work position, the control unit detects this and switches the first check valve device [6] to the work position. .

The operation of this embodiment is similar to that of the first embodiment, but for example, when the vehicle transitions from a high friction road surface to a low friction road surface, or when it makes a so-called μ jump, the wheel cylinder αV A large amount of the pressure fluid is discharged into the reservoir (g). Therefore, when the fluid pressure in the reservoir chamber (1) increases and becomes equal to or higher than a predetermined pressure, the second check valve device ring is switched to the 1 position by detection by the pressure detection section (30a). Due to this, the discharge pressure liquid of the hydraulic pump (■) passes through the check valve port without flowing to the wheel cylinder side, and at this time, the first check valve device A
position) and then return it to the master cylinder (1) side.

This prevents the hydraulic pressure in the reservoir chamber (7) of the second reservoir from increasing and preventing the hydraulic pressure in the wheel cylinder CIIJ from being sufficiently lowered. In other words, it is possible to prevent the locking tendency from proceeding.

FIG. 3 shows a third embodiment of the present invention, but the reference numerals are omitted for parts corresponding to those in FIG. 1, and detailed explanation thereof will be omitted.

In this embodiment, the discharge port of the hydraulic pump (■) is directly connected to the connecting pipe (9) between the wheel cylinder side and the switching valve (8). It is connected to the master cylinder side via 14+1. Shutoff valve no#i
Normally, the J position should be set between the discharge side of the hydraulic pump ■ and the check valve (
41) side, that is, the master cylinder side, and the solenoid portion (40a) is energized and takes a position during drive slip control. This shuts off the discharge port of the hydraulic pump (2) and the master cylinder side. Therefore, normal anti-skid control and drive slip control are performed without any problem, but according to this embodiment, the cutoff valve 140
is provided in the position shown in the figure, so even if it were locked in the shutoff position, that is, in the closed position, the hydraulic control valve could be placed in the on position to release the brake.
You can also hang it. There will be no brakes.

FIG. 4 shows a modification of the check valve device (6) in FIG. 1, and this valve device group is a three-bottom, two-position electromagnetic switching valve, and the check valve device shown in FIG. It is connected to the same position as (6), and when a drive signal is applied to the solenoid part (50a), it switches to the M position, and in the normal on position, the master cylinder side and the switching valve (8) side are interconnected. However, when the solenoid section (SOa) is energized and takes the M position, the discharge side of the hydraulic pump (2) and the switching valve (3) side are communicated. That is, normally the discharge side of the hydraulic pump (to) and the switching valve (8)
When the motor that drives the hydraulic pump ■ malfunctions and the hydraulic pump ■ generates discharge pressure liquid, the switching valve ( 8) It is prevented from being supplied to the wheel cylinder via the This prevents the brake from being applied unexpectedly.

FIG. 5 shows a modification of the switching valve (8) in FIG. When the supply valve 611, which is a position valve, and the discharge valve 630, which is a three-bottom, two-position valve, solenoid parts (51a) and (52a) are not energized, the N and P positions communicate with the master cylinder side and the wheel cylinder side, respectively. However, when these are energized, they change to the 0 or Q position, which cuts off the master cylinder side and the wheel cylinder side, but connects the wheel cylinder side and the reservoir side, making it possible to release the brake. I can do it.

Further, when only the solenoid section (Sta) of the supply valve 6υ is energized, the master cylinder side and the wheel cylinder side are cut off, and the brake can be maintained at a constant level.

FIG. 6 further shows a modification of the switching valve (8). Like the first modification, the switching valve consists of two valves, and the supply valve 51) is similar to the second modification. However, the discharge valve is opened by a 2-point, 2-position electromagnetic switching valve, and the connection to the wheel cylinder is different, and in this modification, the supply valve 5 is connected to the wheel cylinder.
A pipe line connecting D and the discharge valve ω is connected to the wheel cylinder side. Further, a shutoff valve is provided between the wheel cylinder and the discharge port of the hydraulic pump Ω. Discharge valve QFi is a valve that normally assumes the R position and assumes the S position when its solenoid portion (53a) is energized. Further, the shutoff valve is a switching valve that normally takes the T position and takes the U position when the solenoid section (54a) is energized. Usually the answer is N.
It has XR and T positions, and the brake pedal (3)
When the brake pedal is depressed, hydraulic pressure from the master cylinder (1) is transmitted to the wheel cylinders through the supply valve 6υ.

Also, when maintaining the brake fluid pressure, the supply valve 511 is set to 0.
The shutoff valve is switched to position 1 and the shutoff valve is switched to position U. And when the brake is released, the valve 61) is 0.
The discharge valve (1) is in the S position, and the shutoff valve (2) is in the U position. As a result, the pressure fluid from the wheel cylinder is discharged to the reservoir (g) through the pipe α◆. Therefore, the brake is released.

When reapplying the brake, the valve 6D is switched to the N position, the discharge valve θ is switched to the R position, and the cutoff valve 541 is switched to the T position. As a result, the hydraulic pressure of the hydraulic pump (2) is transmitted to the wheel cylinder wcgl.

In addition, in the modified examples shown in FIGS. 5 and 6, the supply valve ciυ
Although the valve is in a cutoff state at the 0 position, it may have a check valve function instead. Furthermore, in the second modification shown in FIG. 6, a cutoff valve is provided on the suction side of the hydraulic pump ■instead of the shutoff valve and the valve device surface provided on the discharge side of the hydraulic pump ■. It may be provided. Further, in both the modified examples shown in FIGS. 5 and 6, a part of the two switching valves can be used as the first valve device according to the present invention.

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

For example, in the embodiment of FIG. 2 or 3, a shutoff valve may be provided in front of the wheel cylinder. In this case, the brake pressure can be kept constant due to this shut-off state.

Also, in the third embodiment, as in the second embodiment, a second check valve device that is switched by the hydraulic pressure of the second reservoir is provided in the pipe connecting the discharge side of the hydraulic pump and the wheel cylinder. It may be provided.

Further, in the second embodiment, the second check valve device may be omitted.

Further, in the above embodiment, the first reservoir is a reservoir for the master cylinder, but it is not limited to this and may be any reservoir that stores brakes in advance.

In addition, in the above embodiment, the second reservoir α is the piston (1
7) is provided with a protrusion to define the reservoir chamber wall, but it may not have such a configuration and may have a flat shape. That is, in the present invention, the second reservoir is considered to be a reservoir that does not store brake fluid in advance, so it is not considered that the brake fluid of the embodiment is stored.

Furthermore, although the above embodiments are used for front-wheel drive vehicles, the present invention is of course applicable to rear-wheel drive vehicles, four-wheel drive vehicles, and other drive types. Furthermore, the present invention is applicable not only to four-wheeled vehicles but also to vehicles such as motorcycles.

Further, in the above embodiments, an X-type brake piping system has been described, but it is of course applicable to those with separate front and rear piping, and also to other piping systems.

Further, in the above embodiment, a four-channel control force type in which each wheel is provided with a hydraulic pressure control valve has been described, but the present invention is not limited to this, and can be applied to three channels, two channels, or one channel.

In addition, in the above embodiment, in the two-channel system of the X brake piping system, which is controlled by hydraulic pressure control valves independently provided for both wheel cylinders of one axle, is a pressure selection means for supplying the lower one of the two wheel cylinder control hydraulic pressures of the one axle, for example, time opening 1@62-913.
The present invention is also applicable to those having pressure selection means as disclosed in No. 52.

Furthermore, in each of the above embodiments, a 20th hydraulic pump may be provided between the hydraulic pump Ω and the second valve device. The stop valve can be opened reliably and quickly, and drive slip control can therefore be performed quickly. Note that the capacity of the second hydraulic pump may be sufficiently low, and it is sufficient that the capacity is sufficient to simply open the check valve on the suction side of the first hydraulic pump.

Generally, hydraulic pumps have check valves on the suction side and discharge side, and a liquid chamber is defined in the casing of the hydraulic pump.The direction from the suction side to the liquid chamber is the forward direction. A check valve is provided on the suction side, and a check valve whose forward direction is the direction from the liquid chamber toward the discharge side is provided.

The above-mentioned check valve provided on the suction side is a check valve whose forward direction is the direction toward the liquid chamber side. That is, the 20th
It is sufficient for a hydraulic pump to have the ability to open this check valve.

Furthermore, in the eleventh and second embodiments, the first valve device normally communicates in both directions, and is switched to the check valve device during drive slip control and hit slip control.
It may also be possible to switch to the check valve device only during drive slip control. Further, the position where the valve acts as a check valve may be replaced with one which acts as a cutoff valve.

Furthermore, in the above embodiments, the first valve device was a solenoid valve, but
Instead, it normally communicates freely in both directions, and when the hydraulic pump pressure exceeds a predetermined value, the forward direction is from the master cylinder side to the hydraulic pressure control valve side. It may be a hydraulic pilot valve that switches to a check valve or shutoff valve position.

Alternatively, the hydraulic pump pressure and the master cylinder pressure may be compared and switched when the hydraulic pump pressure exceeds the master cylinder pressure by a predetermined value or more. Similarly, in place of the first valve device in the third embodiment, it normally communicates freely in both directions, and determines whether the hydraulic pump pressure exceeds a predetermined value or compares the hydraulic pump pressure with the master cylinder pressure. It may also be a hydraulic pilot valve that switches to the cutoff position when the master cylinder pressure or the pressure exceeds a predetermined value.

Furthermore, although the first valve device decoy of the third embodiment takes the blocking position only during driving slip control, it may also take the blocking position during braking slip control, and in that case, it may always take the blocking position. The communication state may be switched to when the braking friction coefficient of the road surface changes from high μ to low μ.

Further, in each of the above embodiments, the second valve device [present] is a hydraulic bait valve, but it may be replaced by a solenoid valve.

In this case, a brake pedal sensor may be provided to normally communicate the fluid between the first reservoir and the second reservoir, and switch to a position where the fluid communication is cut off in response to a signal output by the sensor when the brake pedal is operated. good.

Further, the normal fluid communication may be made to be cut off upon receiving the brake slip control signal during the brake slip control.

Alternatively, it may be normally shut off, and fluid communication may be established in response to the drive slip control signal during drive slip control.

Also, by using a solenoid valve, brake fluid consumption can be reduced.

In any of the above cases, the second valve device is not switched depending on the driver's brake operation, so the operational durability is improved.

Further, a relief valve on the discharge side of the hydraulic pump may be configured to discharge the fluid to the first reservoir side when the discharge pressure of the hydraulic pump exceeds a predetermined value.

Further, in the case of the first embodiment, an accelerator 1 may be provided in place of the relief valve (2) for controlling the discharge pressure liquid of the hydraulic pump.

In addition, in the embodiments shown in Figs. 2 and 3, a check valve as a relief valve may be provided in parallel with the hydraulic pump (g) to release abnormally high discharge pressure liquid to the reservoir (c) side. good.

Further, when the driver depresses the brake pedal during drive slip control, the switching valve may be forcibly returned to the initial position 0, and the electric motor of the hydraulic pump may be stopped.

Furthermore, in the above embodiments, the first valve device is switched from the normal communication position to the check valve position when controlling the drive sleeve 2 and the brake sleeve 17, but instead of this,
During driving slip control, the valve is switched to the check valve position, but during brake slip control, it may be possible to alternately switch between the communicating position and the check valve position.

〔Effect of the invention〕

According to the hydraulic brake control device for a vehicle of the present invention, braking speed control and drive speed control are possible, the brake pedal travel does not extend abnormally, and the first valve device Easy to control including

[Brief explanation of the drawing]

1, 2, and 3 are the first and second embodiments of the present invention, respectively.
FIG. 4, FIG. 5, and FIG. 6 are partial piping diagrams showing a partial modification of the above embodiment. In the figure,

Claims (1)

[Claims] A hydraulic pressure control valve that controls the brake fluid pressure of the wheel braking device in response to a command from a control unit that evaluates braking slip and/or driving slip of the wheels, and reducing the brake fluid pressure by controlling the hydraulic pressure control valve. At this time, a reservoir is provided for storing brake fluid discharged from the wheel brake device via the hydraulic pressure control valve, and the brake fluid in the reservoir is pressurized and supplied to the main pipe connecting the master cylinder and the wheel brake device. In the vehicle hydraulic brake control device, the reservoir has brake fluid in advance, and a first valve device that can cut off fluid communication from the discharge side of the hydraulic pump to the master cylinder side. a first reservoir storing brake fluid; and a second reservoir capable of storing brake fluid; a second valve device capable of cutting off fluid communication is provided in a conduit connecting both reservoirs; is connected to the hydraulic pressure control valve, and a suction side of the hydraulic pump is connected to the second reservoir.