JPH0680071A - Brake hydaulic pressure control device - Google Patents

Abstract

PURPOSE:To get rid of influence of such as piping resistance to perform brake hydraulic pressure control certainly, by closing a traction control change-over valve and operating a pump, and at the same time, exhausting brake fluid in an intermediate liquid reservoir, opening a cutoff valve and transmitting the brake fluid to a driving wheel brake. CONSTITUTION:When slipping of a driving wheel is detected by an electronic control device 17, a traction control change-over valve 11 is closed by instruction generated by the electronic control device 17 for preventing the liquid flow from the reflux point 8d to the branch point 3, and a pump 7 is operated. At the same time, the current flows from the electronic control device 17 to an intermediate liquid reservoir 13, a shape memory alloy spring 24 is energized, develops heat and elongates, and a liquid exhaust part 23 moves to the upper part of a liquid reservoir case 20. By this movement of the liquid exhaust part 23, brake fluid in the liquid reservoir case 20 is exhausted from an exhaust port 21, flowed into a make-up feed route 12, pressurized by the pump 7 and transmitted to a driving wheel brake 4A, through an opened cutoff valve 14, to perform brake control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control system for a vehicle, and more particularly, to a recirculation type antilock device having a structure having both antilock control and traction control functions by utilizing a pump interposed in a recirculation path. The present invention relates to a brake fluid pressure control device.

[0002]

2. Description of the Related Art Conventionally, as a wheel brake fluid pressure device, a wheel brake fluid pressure control valve having a discharge valve in a main flow path from a master cylinder to a wheel brake, and a brake fluid discharged from the brake fluid pressure control valve are provided. There is known a reflux type anti-lock hydraulic device which is composed of an exhaust fluid reservoir which is temporarily stored and a pump which pumps out the brake fluid accumulated in the exhaust fluid reservoir and returns it to the main flow path.

When a traction control function is added to the antilock hydraulic device, if the antilock reflux pump is used as a pressure source for traction control, the maximum effect can be obtained in terms of simplification of the structure. Was expected

However, when the method of using the antilock control pump also as the traction control pump is used, the brake fluid must be supplied to the pump suction side.

There are roughly two known methods for replenishing the brake fluid to the suction side of the pump. 1
One is to provide a replenishment channel directly from the reservoir of the master cylinder to the pump intake side, and one is to branch the replenishment channel from the main channel that connects the discharge port of the master cylinder and the vehicle brake. being classified. In these two known examples, the latter is more advantageous in consideration of the convenience of mounting on the vehicle and the necessity of backflowing the excess brake fluid from the intake port of the master cylinder to the reservoir.

[0006]

However, in the latter method of branching the replenishment passage from the main passage, the intake resistance at the intake port of the master cylinder and the replenishment passage from the master cylinder to the brake fluid pressure control device are The flow rate of brake fluid supplied to the pump is limited due to the piping resistance that reaches the pump and the resistance inside the shutoff valve that closes the supply channel during normal braking.
There is a problem that the rise of the brake fluid pressure in the initial stage of traction control is delayed.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the resistance of the brake fluid from obstructing the flow of the brake fluid and improve the functionality of the traction control.

[0008]

In order to achieve the above object, in the present invention, a drive wheel brake side interposed between two main flow paths between a drive wheel brake communicating with a master cylinder and a non-drive wheel brake. Drive-wheel-side hydraulic pressure control valve and non-drive-wheel brake-side non-drive-wheel-side hydraulic pressure control valve, and discharge fluid that temporarily stores brake fluid discharged from these drive-wheel-side control valve and non-drive-wheel-side control valve Reservoir and brake fluid discharged from the hydraulic pressure control valve by driving the motor,
Alternatively, the brake fluid stored in the discharge fluid reservoir is pumped out, and the pumped brake fluid is returned to the drive wheel side fluid pressure control valve side between the drive wheel side fluid pressure control valve and the master cylinder. A pump that discharges to the reflux point on the main flow path and a supply channel that communicates with the discharge liquid reservoir from the branch point between the reflux point and the master cylinder are interposed to store a certain amount of brake fluid in the fluid reservoir case. Along with an intermediate fluid reservoir that discharges the brake fluid stored during traction control, and a traction control switching valve that is interposed between the branch point and the reflux point to prevent backflow from the reflux point to the master cylinder during traction control. , Is interposed between the intermediate liquid reservoir and the discharge liquid reservoir, and shuts off the communication between the main flow path and the discharge liquid reservoir by closing the master cylinder pressure during antilock control. However, during traction control, the shutoff valve that allows the flow of brake fluid by the communication of the intermediate fluid reservoir and the exhaust fluid reservoir, and at least the locked or slipped state of the drive wheel brakes and non-drive wheel brakes are detected. The drive wheel side hydraulic pressure control valve, the non-drive wheel side hydraulic pressure control valve, a traction control switching valve, and an electronic control device for controlling the operation of the intermediate liquid reservoir, at the time of traction control, the electronic control device In response to a command, the traction control switching valve is closed and the pump is operated to drain the brake fluid in the intermediate fluid reservoir and to control the drive wheel brakes by the brake fluid pumped through the shutoff valve. The present invention provides a brake fluid pressure control device.

The intermediate liquid reservoir has a liquid reservoir case having an outlet for discharging the brake fluid and an opening for inserting a wire connected to an electronic control unit, and is urged downward by a return spring in the liquid reservoir case. And a substantially convex liquid discharge part provided with a spring made of a shape memory alloy that functions to increase the total length due to temperature rise,
The wiring from the electronic control unit is connected to the spring made of the shape memory alloy, the temperature is raised by energization to overcome the urging force of the return spring, and the spring increases the entire length to raise the liquid discharge part to raise the liquid. The configuration may be such that the brake fluid in the storage case is discharged.

The intermediate liquid reservoir is provided with a liquid reservoir case having an outlet for discharging the brake fluid and an opening for inserting a wiring connected to an electronic control unit, and a lower portion of the liquid reservoir case. An electromagnetic solenoid connected to a control device and provided with a projecting piston upward by energization, and a substantially convex liquid discharge part biased by a return spring above the electromagnetic solenoid in the liquid storage case, The wiring from the electronic control unit is connected to the electromagnetic solenoid, and the energization of the return spring overcomes the urging force of the return spring to raise the piston, which raises the liquid discharge portion above the electromagnetic solenoid to brake the liquid storage case. The liquid may be discharged.

[0011]

In the brake fluid pressure control device according to the present invention, when performing traction control, the traction control switching valve is closed in response to a command from the electronic control device, the brake fluid is discharged from the intermediate fluid reservoir, and the shut-off valve is activated. Since the brake fluid is supplied to the suction side of the pump via the pump, the intermediate fluid reservoir communicates with the pump and serves as a supplementary source of brake fluid during traction control.
The suction resistance at the suction port of the master cylinder and the piping resistance from the master cylinder to the replenishing flow path to the brake fluid pressure control device are less likely to be affected, and the suction resistance is reduced and the fluid replacement capacity is enhanced.

Further, the intermediate liquid reservoir has a liquid discharge part provided with a spring made of a shape memory alloy which functions to increase the overall length by temperature rise, and is installed inside the liquid reservoir case, and the spring is energized to Since it is configured to raise and drain the brake fluid in the fluid reservoir case,
Low cost and long-term use.

Further, at the same time when the piston is raised by energizing the intermediate liquid reservoir by using the electromagnetic solenoid,
If the upper discharge part is raised to discharge the brake fluid in the fluid storage case, the brake fluid in the fluid storage case can be reliably discharged.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. In the first embodiment of the present invention, as shown in FIG. 1 using the intermediate liquid reservoir 13 shown in FIG.
The drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B are interposed between the drive wheel brake 4A and the non-drive wheel brake 4B. Further, an exhaust fluid reservoir 6 for temporarily storing the brake fluid exhausted from the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B is provided, and the brake fluid stored in the exhaust fluid reservoir 6 is also provided. A pump 7 for pumping out the liquid and returning it to the main flow path 2 is provided. Further, the drive wheel brake 4A and the non-drive wheel brake 4 are
Detecting the brake control state of B, the drive wheel side control valve 5
An electronic control unit 17 for controlling A and the non-driving wheel side control valve 5B is provided to enable antilock control.

The master cylinder 1 has two discharge ports 1.
Since the two hydraulic systems provided with a and 1b and projecting from the discharge ports 1a and 1b have the same configuration, only the hydraulic system that projects from the discharge port 1a will be described.

In the master cylinder 1, the main flow path 2 protruding from the discharge port 1a as a hydraulic system branches into the main flow paths 2a and 2b at a branch point 3 and the main flow paths 2a and 2b are driven wheel brakes respectively. 4A and the non-driving wheel brake 4B. By this connection, the brake fluid pressure from the master cylinder 1 is transmitted to the driving wheel brakes 4A and the non-driving wheel brakes 4B, respectively, thereby enabling the brake control.

In this embodiment, the drive wheel side hydraulic pressure control valve 5 is used.
As shown in FIG. 1, the A and non-driving wheel side hydraulic control valve 5B is a three-position type that performs pressurization, holding, and depressurization, but it may be a two-position type that does not have a holding position. Further, the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B are
A check valve (not shown) is often added in parallel to quickly reduce the brake fluid pressure when the brake pedal is released during antilock control.

The drainage reservoir 6 has a discharge port 5A for the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B.
-1,5B-1 communicates with the return path 8a. Accordingly, during brake control, when the brake fluid discharged from the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B exceeds the discharge amount limit of the pump 7 described later, It can be temporarily stored in the reservoir 6. This prevents the pump 7 from being overloaded.

The pump 7 is provided with a motor 7a, communicates with the discharge liquid reservoir 6 via a return passage 8b and a return passage 8a, and a discharge port 7b of the pump 7 is provided at a return point 8d in the main passage 2a. Is communicated via a reflux passage 8c. As a result, the pump 7 pumps out the brake fluid discharged from the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B or the brake fluid temporarily stored in the discharge fluid reservoir 6. Can be sent to the reflux point 8d on the main flow path 2a. Further, in order to suppress the discharge pulsation of the pump 7, the buffer solution reservoir 9 is communicated with the reflux passage 8c, and the throttle 10 is provided on the reflux passage 8c.

A basic anti-lock hydraulic pressure control device is formed by connecting the electronic control device 17 (detailed description will be given later) to the above-mentioned configuration, and the pump 7 of the anti-lock hydraulic pressure control device is operated by the traction. A traction control switching valve 11 is provided between the return point 8d and the branch point 3 in order to provide a brake fluid pressure control device that serves as a pump that also serves as a control. Further, a replenishment flow passage 12 that connects the branch point 3 and the discharge liquid reservoir 6 is provided, and an intermediate liquid reservoir 13 is provided on the replenishment passage 12. Further, a shutoff valve 14 is interposed between the intermediate liquid reservoir 13 and the discharge liquid reservoir 6 to form a brake fluid pressure control device.

The traction control switching valve 11
Is a normally open switching valve that allows the liquid flow during anti-lock control and during normal operation. When performing traction control, the liquid flow of the brake liquid from the reflux point 8d to the branch point 3 is prevented to prevent the brake liquid from flowing. The backflow to the master cylinder 1 is prevented. When the hydraulic pressure of the brake fluid from the pump 7 rises abnormally, the relief valve 15 of high pressure (the upper limit of the hydraulic pressure required for traction control, for example, 50 bar) is exceptionally provided so as to allow the reverse flow. It is provided in parallel with the traction control switching valve 11. Specifically, the inlet side of the relief valve 15 is connected to the return passage 8 as described above.
In addition to being connected to c, the discharge side is connected to the supply channel 12a.

Further, if necessary, a throttle 16 that does not impair the service brake performance is provided between the master cylinder 1 and the branch point 3, and the combination of the intermediate liquid reservoir 13 and the throttle 16 is the buffer liquid reservoir 9 and the throttle liquid. You may make it reinforce the relaxation effect by the combination of 10.

The non-driving wheel brake 4B and the non-driving wheel side hydraulic pressure control valve 5B may be branched from the downstream side of the traction control switching valve 11 like the driving wheel brake 4A and the driving wheel side hydraulic pressure control valve 5A. it can. However, in this embodiment, the branch is upstream. This is because by branching upstream, it is not necessary to operate the control valve 5B during traction control, and the non-drive wheel brake 4B can be immediately pressurized when the brake pedal is depressed.

As shown in FIG. 2, the intermediate liquid reservoir 13 has a box-shaped liquid reservoir case 20 having an outlet 21 for discharging brake fluid and an opening 22 for wiring, and the inside of the liquid reservoir case 20. And a substantially convex liquid discharge part 23 provided with a spring 24 made of a shape memory alloy. Further, the liquid discharge part 23 is configured by mounting a return spring 25 so as to be interposed between the return spring 25 and the liquid storage case 20, and the discharge port 21 to the branch point 3 to the replenishment flow path 12
It communicates via a.

The above-mentioned substantially convex liquid discharging portion 23 is provided with a notch 26 below the protruding portion along the outer peripheral side surface, a rubber seal 27 is attached to the notch 26, and the liquid discharging portion 23 is moved upward in FIG. At this time, the brake fluid is prevented from leaking out from other than the discharge port 21. Further, the liquid discharge section 23 is
A cavity 28 for mounting the spring 24 made of the shape memory alloy is provided with a concave cross section. Further, in order to position the return spring 25, a convex portion 29 is provided so that the liquid discharge portion 23 is always urged downward by the return spring 25 in FIG.

The intermediate liquid reservoir 13 having the above-described structure has a wire inserted through the opening 22 of the liquid reservoir case 20 and is connected to a spring 24 made of a shape memory alloy in the liquid discharge portion 23. In addition, the liquid discharge part 23 has a return spring 25.
Thus, the brake fluid is set to be stored in the gap between the fluid discharge portion 23 and the fluid storage case 20 while being urged downward in the fluid storage case 20.

The intermediate liquid reservoir 13 is normally operated when the liquid discharge part 23 is biased downward in the liquid reservoir case 20 and the traction control is performed by a command from the electronic control unit 17. First, the electronic control unit 1
When 7 detects idling (slip) of the drive wheel, an electric current is applied from the electronic control unit 17 to the spring 24 made of a shape memory alloy through the wiring. This energization causes the spring 2
4 generates heat and the spring 24 generates an extension force (a function of increasing the total length) to return to the original shape.
When the extension force of No. 4 overcomes the urging force of the return spring 25, the liquid discharge part 23 moves to the discharge port 21 side of the liquid storage case 20.

By the movement of the liquid discharge portion 23, the brake liquid in the liquid storage case 20 is pushed out from the discharge port 21 communicating with the replenishment passage 12 and supplied to the replenishment passage 12. There is.

The shut-off valve 14 is a normally open valve that opens and closes depending on the presence or absence of pressure in the pipe to be connected. The shut-off valve 14 communicates with the intermediate liquid reservoir 13 via a replenishment flow path 12b, and the discharge liquid reservoir 6 is provided. To the replenishment channel 12c.

The shut-off valve 14 having the above-mentioned structure allows the liquid flow from the intermediate liquid reservoir 13 to the discharged liquid reservoir 6 in the open state during normal operation and traction control, and during normal brake operation and antilock control. , The branch point 3 by closing the valve by the brake fluid pressure discharged from the master cylinder 1.
It is designed to prevent the liquid from flowing to the discharge liquid reservoir 6.

The electronic control unit 17 includes the drive wheel brake 4A, the non-drive wheel brake 4B, the drive wheel side hydraulic pressure control valve 5A, the non-drive wheel side hydraulic pressure control valve 5B, the traction control switching valve 11, and the intermediate liquid reservoir. 13, and the motor 7a
Each of them can be controlled by connecting them to each other via wirings 17a to 17g.

The electronic control unit 17 controls the wiring control of the drive wheel brakes 4A and the non-drive wheel brakes 4B from the wheel speed sensor (not shown) provided for each wheel.
Anti-lock control or traction control is performed by detecting through 7a and 17b.

More specifically, the electronic control unit 17 controls the drive wheel brake 4A when the driver performs brake control.
Alternatively, when the locking tendency of the non-driving wheel brake 4B is detected, a command is issued to the driving wheel side hydraulic pressure control valve 5A, the non-driving wheel side hydraulic pressure control valve 5B and the motor 7a to perform antilock control.

On the other hand, when the electronic control unit 17 detects the tendency of the drive wheels to slip (slip) when the vehicle starts or accelerates, the drive wheel hydraulic control valve 5A, the traction control switching valve 11, and the motor 7a. Then, a command is issued to the intermediate liquid reservoir 13 to perform traction control.

Next, the operation process of the brake fluid pressure control device having the above configuration will be described. First, by a normal brake operation, the brake fluid flows from the master cylinder 1 through the main flow path 2 to the drive wheel brakes 4A and the non-drive wheel brakes 4B, and the brake control of the drive wheel brakes 4A and the non-drive wheel brakes 4B is performed. . At this point,
The traction control switching valve 11 is in an open state that allows the flow of brake fluid, and at the same time, the shutoff valve 14 is closed by the brake fluid pressure from the master cylinder 1 to prevent the flow of brake fluid, and the pump 7 is Not working. Further, the flow path indicated by the thick line in FIG. 3 is a flow path through which the brake fluid flows during normal brake operation.

Next, due to excessive braking,
When the lock tendency of the wheels is detected by the electronic control unit 17, antilock control is performed. Specifically, in response to a command from the electronic control unit 17, the drive wheel side hydraulic pressure control valve 5A
And the non-driving wheel side hydraulic pressure control valve 5B is closed to prevent excessive flow of the brake fluid from the master cylinder 1. At the same time, the valves of the discharge ports 5A-1, 5B-1 of the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B are opened, and the pump 7 is driven by the drive of the motor 7a.
The flow path indicated by the thick line in FIG. 4 is the flow path of the brake fluid in the antilock control for reducing the brake fluid pressure.

The driving wheel side hydraulic pressure control valve 5A and the non-driving wheel side hydraulic pressure control valve 5A and the non-driving wheel side hydraulic pressure control are performed by opening and closing the valves of the driving wheel side hydraulic pressure control valve 5A and the non-driving wheel side hydraulic pressure control valve 5B. The pressure reduction control of the valve 5B is performed. The brake fluid discharged from the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B is pumped out by the pump 7, discharged to the recirculation point 8d, and returned to the main flow path 2a.

The brake fluid returned to the main flow path 2a is
It is returned to the master cylinder 1 through the branch point 3. During the anti-lock control, when the amount of brake fluid discharged exceeds the discharge capacity of the pump 7, the brake fluid is temporarily stored in the drainage reservoir 6 and then the pump 7 is braked in the drainage reservoir 6. I try to pump out the liquid.

Next, when the wheel lock tendency disappears, the electronic control unit 17 issues a re-pressurizing command, and the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B are set to the master cylinder 1. And the discharge port 5A-
1,5B-1 is closed. As a result, the driving wheel brakes 4A and the non-driving wheel brakes 4B again receive the hydraulic pressure of the brake fluid from the master cylinder 1 and perform the brake control.

The opening / closing operation of the drive wheel side hydraulic pressure control valve 5A and the non-drive wheel side hydraulic pressure control valve 5B is repeated to perform antilock hydraulic pressure control for shortening the braking distance of the brake without locking the wheels.

On the other hand, when it is detected by the electronic control unit 17 that the drive wheels slip (slip) when the vehicle starts or accelerates, the traction control switching valve 11 is closed by a command from the electronic control unit 17. To prevent the liquid flow from the reflux point 8d to the branch point 3 and to prevent the electronic control device 17 from operating.
In response to this command, the pump 7 is operated by driving the motor 7a.

At the same time, an electric current is made to flow from the electronic control unit 17 to the intermediate liquid reservoir 13, and the intermediate liquid reservoir 13 shown in FIG.
The spring 24 made of the shape memory alloy is energized.
This energization causes the spring 24 to generate heat and expand, whereby the liquid discharge portion 23 moves above the liquid storage case 20.

Due to the movement of the liquid discharge portion 23, the brake liquid stored in the liquid storage case 20 is discharged from the discharge port 21, and the discharged brake liquid is supplied to the replenishing passage 12.
Flow through the shut-off valve 14 in the open state, and the negative pressure on the suction side of the pump helps the brake fluid to flow through the thick line shown in FIG. ,
The brake control is performed by being transmitted to the drive wheel brake 4A.

Incidentally, the brake fluid pressure control during the traction control naturally uses the drive wheel side fluid pressure control valve 5A, and the drive wheel side fluid pressure control valve 5A is instructed by the electronic control unit 17. The traction control is performed by opening and closing the valve.

Further, the non-driving wheel side hydraulic pressure control valve 5B is
Although the valve is open, the traction control liquid flow is performed by the suction force of the pump 7 and the traction control switching valve 11 is closed, so that the non-drive wheel side hydraulic pressure control valve 5B is braked. No hydraulic pressure is applied.

Further, when the brake fluid discharge pressure of the pump 7 rises abnormally, it is returned to the replenishment flow path 12a upstream of the intermediate fluid reservoir 13 through the relief valve 15 of high pressure setting, and the pump 7 If the allowable inhalation amount is exceeded,
The drainage reservoir 6 temporarily stores the brake fluid.

When the electronic control unit 17 detects that the slip tendency has disappeared by the brake control of the drive wheels, the traction control switching valve 11 opens and at the same time, the energization from the electronic control unit 17 to the intermediate liquid reservoir 13 is cut off. Be drunk As a result, the spring 2 of the intermediate liquid reservoir 13
As the heat of 4 cools, the extension force of the spring 24 made of a shape memory alloy disappears, and the liquid discharge portion 23 is gradually moved downward by the urging force of the liquid discharge portion 23 by the return spring 25. At this time, the brake fluid in the main passage 2 and the replenishing passage 12 simultaneously flows into the liquid storage case 20.

In the brake fluid pressure control device of the present invention, as shown in FIG.
Since the respective parts are communicated with each other in the configuration shown in Fig. 4, especially during traction control, the brake fluid discharged from the intermediate fluid reservoir 13 flows to the drive wheel brake 4A, and idling of the drive wheel can be controlled. it can. As a result, problems such as suction resistance in the master cylinder 1 and piping resistance from the master cylinder 1 to the supply passage 12 to the brake fluid pressure control device can be solved.

In the second embodiment of the present invention, the intermediate liquid reservoir 18 shown in FIG. 6 is used, and the structure shown in FIG. 1 is used in the same way as in the first embodiment. Description is omitted.

The intermediate liquid reservoir 18 is provided with an outlet 31 communicating with the replenishing passage 12 and a liquid reservoir case 30 having an opening 32 into which wiring from the electronic control unit 17 is inserted, and the inside of the liquid reservoir case 30. An electromagnetic solenoid 33 that raises the convex piston 34 by energization from the electronic control unit 17 is provided below. In addition, a substantially convex liquid discharge part 37 located above the electromagnetic solenoid 33 is provided by sliding inside the liquid storage case 30, and a return spring 40 is interposed between the liquid storage case 30 and the liquid storage case 30 to mount the liquid discharge part 37. There is.

The electromagnetic solenoid 33 is a coil that raises the piston 34 by connecting the convex piston 34 to the side of the piston 34 and connecting the wiring from the electronic control unit 17 to supply electricity. 35 are provided.

The case 36 for accommodating the piston 34 and the coil 35 has an opening 36a slightly larger than the outer circumference of the protruding portion of the piston 34 at the center of the case 36, and the wiring from the electronic control unit 17 is provided. A hole 36b for attaching to the coil 35 is provided corresponding to the position of the wiring opening 32 of the liquid reservoir case 30.

The electromagnetic solenoid 33 having the above-mentioned structure is adapted to raise the piston 34 by causing a current to flow through the coil 35 and energizing it in response to a command from the electronic control unit.

The substantially convex liquid discharging portion 37 is provided with a notch 38 below the protruding portion along the outer peripheral side surface, a rubber seal 39 is attached to the notch 38, and the liquid discharging portion 37 discharges the liquid storage case 30. The brake fluid is prevented from leaking from other than the discharge port 31 when it moves to the 31 side. Further, the liquid discharge portion 37 is provided with a convex portion 41 for preventing the return spring 40 from being rubbed, and the liquid discharge portion 37 is constantly caused by the return spring 40 to cause the electromagnetic solenoid 33.
It is in a state of being biased to the upper part of.

The intermediate liquid reservoir 18 has the liquid discharge portion 37.
The return spring 40 causes the electromagnetic solenoid 3 to
The brake fluid is stored in the gap between the fluid storage case 30 and the fluid discharge portion 37 while being urged to the upper surface of the case 36 of No. 3.

When the electronic control unit 17 detects that the drive wheels are idling (slip), the intermediate liquid reservoir 18 having the above-mentioned configuration is provided with the coil 35 by a command from the electronic control unit 17.
Is energized via wiring, and this energization causes the piston 34 to rise. When the ascending force of the piston 34 overcomes the biasing force of the return spring 40, the piston 34 ascends while pushing the liquid discharge portion 37 upward.

The brake fluid stored in the fluid reservoir case 30 is pushed out from the discharge port 31 communicating with the replenishment flow passage 12 by the liquid discharge portion 37 that rises together with the piston 34, and the brake fluid is supplied to the replenishment flow passage 12. It is supplied to control traction.

The intermediate liquid reservoir 18 plays the same role as the intermediate liquid reservoir 13 of the first embodiment at the time of traction control, and performs the brake control of the drive wheel brake 4A. Therefore, detailed description of the operation process is omitted.

[0059]

The brake fluid pressure control device according to the present invention discharges the brake fluid from the intermediate fluid reservoir by closing the totraction control switching valve according to a command from the electronic control device when performing the totraction control. As a result, the brake fluid is supplied to the suction side of the pump via the shut-off valve in the open state.Therefore, during traction control, the intermediate fluid reservoir communicates with the pump to replenish the brake fluid. As it becomes a source, it is less affected by the suction resistance at the suction port of the master cylinder and the piping resistance from the master cylinder to the replenishment flow path of the brake fluid pressure control device, which solves the problem of suction resistance and Ability increases. In addition, even if the brake fluid pressure control device is simplified by using the pump for anti-lock control and the pump for traction control as well, the delay in the rise of the brake fluid pressure at the initial stage of traction control is eliminated.

In addition, the intermediate liquid reservoir has a liquid discharge part provided with a spring made of a shape memory alloy which functions to increase the total length by temperature rise, and is installed inside the liquid reservoir case. Since the brake fluid in the fluid storage case is raised to be discharged, the cost can be reduced and the stable brake fluid can be discharged for a long period of time.

Further, the intermediate liquid reservoir is constructed such that an electromagnetic solenoid that functions to raise the piston by energization is used to raise the liquid draining portion located above to drain the brake fluid in the liquid reservoir case. Therefore, various effects such as reliable discharge of the brake fluid in the fluid reservoir case can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a brake fluid pressure control device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing an intermediate liquid reservoir of the first embodiment.

FIG. 3 is an operation explanatory diagram showing a normal brake operation of the first embodiment.

FIG. 4 is an operation explanatory view showing the antilock control of the first embodiment.

FIG. 5 is an operation explanatory view showing traction control of the first embodiment.

FIG. 6 is a sectional view showing an intermediate liquid reservoir of a second embodiment of the present invention.

[Explanation of symbols]

 1 master cylinder 2, 2a, 2b main flow path 3 branch point 4A driving wheel brake 4B non-driving wheel brake 5A driving wheel side hydraulic pressure control valve 5B non-driving wheel side hydraulic pressure control valve 6 drainage reservoir 7 pump 8a, 8b, 8c Reflux path 8d Reflux point 11 Traction control switching valve 12 Replenishment flow path 13 Intermediate liquid reservoir 14 Shutoff valve 17 Electronic control device

Claims (3)

[Claims] 1. A drive-wheel-side hydraulic control valve on the drive-wheel brake side and a non-drive-wheel brake-side non-control on the drive wheel brake side interposed in two main flow paths between the drive wheel brake and the non-drive wheel brake communicating with the master cylinder, respectively. The drive-wheel-side hydraulic pressure control valve, the drainage sump that temporarily stores the brake fluid discharged from the drive-wheel-side control valve and the non-drive-wheel-side control valve, and the hydraulic pressure control valve that discharges the brake fluid by driving the motor. Brake fluid or the brake fluid stored in the discharge fluid reservoir is pumped out, and the pumped brake fluid is transferred to the drive wheel side fluid pressure control valve side between the drive wheel side fluid pressure control valve and the master cylinder. A pump that discharges the brake fluid to the reflux point on the main flow path and a supply channel that communicates with the discharge fluid reservoir from the branch point between the reflux point and the master cylinder are placed in the fluid storage case. Bu An intermediate fluid reservoir that stores the rake fluid and discharges the brake fluid that is stored during traction control, and a traction that is interposed between the branch point and the reflux point to prevent backflow from the reflux point to the master cylinder during traction control. It is interposed between the control switching valve and the above-mentioned intermediate liquid reservoir and exhaust liquid reservoir, and is closed by the master cylinder pressure during antilock control to shut off the communication between the main flow path and the exhaust liquid reservoir. A shut-off valve that allows the flow of brake fluid through the communication of the fluid reservoir and the drain fluid reservoir, and at least the drive wheel side hydraulic pressure control valve, which detects the locked state or the slip state of the drive wheel brake and the non-drive wheel brake. An electronic control unit that controls the operation of the drive wheel side hydraulic pressure control valve, traction control switching valve, and intermediate reservoir During traction control, the traction control switching valve is closed and the pump is operated in response to a command from the electronic control unit, the brake fluid in the intermediate fluid reservoir is discharged, and the pump is applied via the shutoff valve. A brake fluid pressure control device for controlling a drive wheel brake by a pressurized brake fluid. 2. The intermediate liquid reservoir is provided with a liquid reservoir case having an outlet for discharging brake fluid and an opening for inserting a wiring connecting to an electronic control unit, and a return spring provided below the liquid reservoir case. And a substantially convex liquid discharge part provided with a spring made of a shape memory alloy that acts to increase the overall length when the temperature rises, and the wiring from the electronic control unit is made of the shape memory alloy. It is connected to a spring, and the temperature is raised by energization to overcome the urging force of the return spring and the spring increases its total length to raise the liquid discharge part to discharge the brake liquid in the liquid storage case. The brake fluid pressure control device according to claim 1, which is characterized in that. 3. The liquid reservoir case having an outlet for discharging brake fluid and an opening for inserting a wiring connected to an electronic control unit, and the intermediate liquid reservoir is located under the liquid reservoir case, An electromagnetic solenoid that is connected to a control device and has a protruding piston upward when energized, and a substantially convex liquid discharge portion that is biased by a return spring above the electromagnetic solenoid in the liquid storage case, The wiring from the electronic control unit is connected to the electromagnetic solenoid, and the energization of the return spring overcomes the urging force of the return spring to raise the piston, which raises the liquid discharge portion above the electromagnetic solenoid to brake the liquid storage case. The brake fluid pressure control device according to claim 1, wherein the brake fluid pressure control device is configured to discharge fluid.