JPH08133045A - Displacement variable anti-lock braking device - Google Patents

Abstract

PURPOSE: To provide an anti-lock braking device requiring no high pressure accumulator, no pressure switch, no large size reservoir tank, and the like. CONSTITUTION: When a wheel is locked, brake fluid inside a pressurizing chamber 12 flows out to a reservoir via a decay valve 6, and the first hydraulic control piston 3 is moved to the left side in the figure, and at the same time, a valve rod 14b is also moved to the left side, and then, a check valve 14 is closed. Under this condition, brake fluid inside a wheel cylinder flows into the inside of a pressure reducing chamber 13 and its pressure is reduced. On the other hand, the brake fluid inside the reservoir is pumped up by a hydraulic pump so as to flow into a pressure storage chamber 21. In another pressurization, a hold valve 5 is opened, and the decay valve 6 is closed, so that the second hydraulic control piston 4 is moved, and as a result, the brake fluid flowing in the pressure storage chamber 21 is let flow into the pressurization chamber 12. By means of the brake fluid flowing into the pressurization chamber 12, the first hydraulic control piston 3 is moved, and a brake is pressurized again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock brake device, and more particularly to a high pressure accumulator,
The present invention relates to a small, lightweight and inexpensive volume-variable antilock brake device that does not require a pressure switch, a large reservoir tank, or the like.

[0002]

2. Description of the Related Art Conventionally, a variable volume type is known as a type of antilock brake device. This device has a cut valve in the middle of the main fluid passage that connects the master cylinder and the wheel cylinder to shut off the main fluid passage, and a hydraulic control is provided in a hydraulic control housing provided on the wheel cylinder side of the cut valve. A second hydraulic chamber in which a piston is provided slidably, and the hydraulic control piston communicates with a wheel cylinder and a cut valve in the hydraulic control housing, and the first hydraulic chamber is cut off from the first hydraulic chamber. It is divided into and. Then, the hydraulic pressure in the second hydraulic chamber is increased / decreased by the control of the electromagnetic hydraulic pressure control valve to move the hydraulic pressure control piston forward and backward, and the hydraulic pressure in the wheel cylinder is controlled so that the slip ratio of the wheel falls within an appropriate range. (Japanese Patent Application No. 5-467).

[0003]

However, in the variable volume type antilock brake device as described above,
A high-pressure accumulator and a pressure switch to monitor the pressure are required, and a large reservoir tank for storing brake fluid in the anti-lock control hydraulic circuit is required. Increase. Further, since the accumulator and the pressure switch used are expensive, there is a problem that the device cost is increased.
Therefore, the present invention provides a novel antilock brake device that does not require a high pressure accumulator, a pressure switch, a large reservoir tank, etc. in a variable volume antilock brake device, and an object thereof is to solve the above problems. To do.

[0004]

Therefore, the technical solution adopted by the present invention is a volume-variable type antilock brake device, which comprises a first hydraulic pressure partitioning a pressurizing chamber 12 and a depressurizing chamber 13. The control piston 3 and the second hydraulic pressure control piston 4 that divides the pressure accumulating chamber 21 and the spring accommodating chamber 22 are provided, and the brake fluid in the pressurizing chamber 12 is passed through the decay valve 6 during depressurization of the antilock control. The discharge liquid is pumped up by the hydraulic pressure pump 7, the discharge liquid is accumulated in the pressure accumulating chamber 21, and the brake fluid in the pressure accumulating chamber 21 is supplied to the pressurizing chamber 12 at the time of repressurization so that the repressurizing can be executed. It is characterized by.

[0005]

When the wheels are locked, the hold valve is closed, the decay valve is opened, and the hydraulic pump 7 is operated. Then, the brake fluid in the pressurizing chamber 12 partitioned by the first hydraulic pressure control piston 3 flows out to the reservoir via the open decay valve 6, and the first hydraulic pressure control piston 3 causes the hydraulic pressure from the wheel cylinder to flow. Is moved to the left in the figure, the valve rod 14b is also moved to the left, and the check valve 14 is closed. In this way, the brake fluid in the wheel cylinders flows into the decompression chamber 13, and the brake fluid pressure is reduced. Further, the brake fluid in the reservoir is pumped up by the hydraulic pump 7 that operates almost at the same time and flows into the pressure accumulating chamber 21 defined by the second hydraulic pressure control piston 4.

During repressurization, the hold valve 5 opens,
Since the decay valve 6 is closed, the second hydraulic pressure control piston 4 is moved by the hydraulic pressure of the master cylinder and the urging force of the spring 23, whereby the brake fluid that has flowed into the pressure accumulating chamber 21 is held. Valve 5 → Pressurization chamber 12 partitioned by the first hydraulic pressure control piston
Flows into. The first hydraulic pressure control piston 3 is moved by the brake fluid that has flowed into the pressurization chamber, the brake fluid that has flowed into the decompression chamber 13 returns to the wheel cylinders 2, and the brake is repressurized.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an antilock brake device according to an embodiment of the present invention. The figure shows a brake piping system connecting the master cylinder and one wheel cylinder, and the piping systems for other wheel cylinders have the same configuration. Further, the electronic control device for controlling the valve is the same as the conventional one, and therefore the description thereof is omitted here.

In the figure, 1 is a connection port with a master cylinder, 2 is a connection port with a wheel cylinder, 3 is a first hydraulic pressure control piston, 4 is a second hydraulic pressure control piston, 5 is a hold valve, and 6 is a decay valve. A valve, 7 is a hydraulic pump, and 8 is a reservoir.

The first hydraulic pressure control piston 3 is slidably arranged in a cylinder 11 formed in the hydraulic pressure control housing 10, and the piston 3 allows the interior of the cylinder 11 to be pressurized and decompressed. It is divided into and. Pressure chamber 1
2 is connected to the hold valve 5 and the decay valve 6 as shown in the drawing, and the decompression chamber 13 is connected to the connection port 2 of the wheel cylinder. Further, the decompression chamber 13 communicates with a connection port 1 to the master cylinder and a spring accommodating chamber 22 of the second hydraulic pressure control piston 4 described later via a check valve 14. Check valve 14 is ball 1
4a, valve rod 1 provided on the first hydraulic control piston 3
4b, a spring 14c, and a valve seat 14d, and the ball 14a is normally operated by the valve rod 14b.
And the decompression chamber 13 communicates with the master cylinder side. Further, in the check valve 14, when the first hydraulic pressure control piston 3 moves to the left in the drawing, the ball 14a and the valve seat 14d come into contact with each other and disconnect the connection with the master cylinder. In the figure, 15 and 16 are plugs.

The second hydraulic pressure control piston 4 is slidably arranged in a cylinder 20 formed in the hydraulic pressure control housing 10, and the piston 4 allows the accumulator chamber 21 and the spring accommodating chamber 22 in the cylinder 20. It is divided into and. The accumulator chamber 21 communicates with the discharge port of the hydraulic pump and the hold valve 5 as shown in the drawing, and the spring accommodating chamber 22 communicates with the check valve 14 and the connection port 1 with the master cylinder as described above. The second hydraulic pressure control piston 4 is normally urged to the left as shown by the spring 23 in the spring accommodating chamber. In the figure, 17 is a plug.

The suction port of the hydraulic pump 7 is connected to the decay valve 6 and the reservoir 8 as is well known, and the pump 7 is operated during depressurization of the antilock control to pump up the brake fluid from the reservoir 8 or the wheel cylinder. Is able to. The operation of the hydraulic pump and the opening / closing timings of the hold valve and the decay valve during the antilock control are well known in the art, and are not a feature of the present invention, so a detailed description thereof will be omitted here.

The operation of the antilock brake device having the above structure will be described in association with the antilock control. [During normal braking] First hydraulic pressure control piston 3 and second
The hydraulic pressure control pistons 4 are maintained in the illustrated state, so that the check valve 14 is opened and the decompression chamber 1 is opened.
3 communicates with the master cylinder cylinder 1 side. Therefore, the brake fluid pressure generated in the master cylinder is supplied to the wheel cylinder through the connection port 1-> the open check valve 14-> the decompression chamber 13-> the connection port 2 of the wheel cylinder to apply the brake. When the brake is released, the brake fluid in the wheel cylinder flows back to the master cylinder through the passage opposite to the above, and the brake is released.

[During Antilock Control] When the wheels fall into the locked state during brake operation, a detection device (not shown) detects the lock of the wheels, and the electronic control device operates the hold valve, the decay valve, and the hydraulic pump. . That is, when the wheels are locked, the hold valve is closed, the decay valve is opened, and the hydraulic pump 7 is operated. Then the first
The brake fluid in the pressurizing chamber 12 partitioned by the hydraulic pressure control piston 3 flows out to the reservoir through the open decay valve 6, and the first hydraulic pressure control piston 3 is driven by the hydraulic pressure from the wheel cylinder in the figure. The check valve 14 is moved to the left and the valve rod 14b is also moved to the left to close the check valve 14. That is, since the pressure in the pressurization chamber 12 is reduced, the brake fluid flows into the pressure reduction chamber 13 while moving the first hydraulic piston 3 to the left in the figure by the brake fluid pressure in the wheel cylinder, and the brake fluid pressure is reduced. Is decompressed. Further, the brake fluid in the reservoir is pumped up by the hydraulic pump 7 that operates almost at the same time and flows into the pressure accumulating chamber 21 defined by the second hydraulic pressure control piston 4. When the brake fluid flows into the re-pressurizing chamber 21, the second hydraulic pressure control piston 4 moves against the biasing force of the spring, and the brake fluid in the spring accommodating chamber 22 is returned to the master cylinder.
As described above, the pressure reduction of the wheel cylinder during the antilock control is performed by the movement of the first hydraulic pressure control piston to increase the volume of the pressure reduction chamber 13.

Repressurization during antilock control is executed as follows. Hold valve 5 when re-pressurizing
Opens and the decay valve 6 closes. Even in this state, the hydraulic pump 7 is operating, but the decay valve 6 is closed, so that it is in the idling state. Further, the second hydraulic pressure control piston 4 moves to the left in the drawing due to the hydraulic pressure of the master cylinder and the urging force of the spring 23, whereby the brake fluid that has flowed into the pressure accumulating chamber 21 is held. The valve 5 flows into the pressurizing chamber 12 defined by the first hydraulic pressure control piston, and moves the first hydraulic pressure control piston 3 to the right in the figure. By the movement of the piston 3, the brake fluid that has flowed into the decompression chamber 13 returns to the wheel cylinder 2 and the brake is repressurized. It should be noted that the check valve 14 is closed because the first hydraulic pressure control piston does not move to the right side in the figure at the time of this repressurization. As described above, in the present invention, the brake hydraulic pressure can be accurately controlled by changing the volumes of the pressurizing chamber and the depressurizing chamber by the first hydraulic pressure control piston and the second hydraulic pressure control piston. Note that, as in the conventional case, the brake fluid pressure holding state during the antilock control is executed by closing the hold valve and the decay valve.

[0015]

As described in detail above, in the variable volume type antilock brake device of the present invention, a high pressure accumulator in the antilock brake device, a pressure switch for monitoring the pressure, and an antilock control are provided. Since the reservoir tank for storing the brake fluid is not required in the hydraulic circuit for use, the entire apparatus can be reduced in size and weight. Further, since the accumulator and the pressure switch are not necessary, the cost of the device can be reduced. It is possible to obtain excellent effects such as.

[Brief description of drawings]

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

[Explanation of symbols]

 1 Connection Port to Master Cylinder 2 Connection Port to Wheel Cylinder 3 First Hydraulic Pressure Control Piston 4 Second Hydraulic Pressure Control Piston 5 Hold Valve 6 Decay Valve 7 Hydraulic Pump 8 Reservoir 10 Hydraulic Control Housing 11 Cylinder 12 Pressurization Chamber 13 Decompression chamber 14 Check valve 20 Cylinder 21 Accumulation chamber 22 Spring accommodation chamber 23 Spring

Claims (4)

[Claims] 1. A variable volume type anti-lock brake device, wherein the device defines a first hydraulic control piston 3 for partitioning a pressurizing chamber 12 and a depressurizing chamber 13, a pressure accumulating chamber 21 and a spring accommodating chamber 22. The second hydraulic pressure control piston 4 is provided, and the brake fluid in the pressurizing chamber 12 is pumped up by the hydraulic pressure pump 7 via the decay valve 6 at the time of depressurization in the antilock control, and the discharged fluid is stored in the pressure accumulating chamber 21. An antilock brake device of a variable volume type, characterized in that pressure is accumulated and the brake fluid in the pressure accumulating chamber 21 is supplied to the pressurizing chamber 12 at the time of repressurizing so that repressurizing can be performed. 2. The volume according to claim 1, wherein the accumulator chamber 21 communicates with a discharge port of the hydraulic pump 7 and the hold valve 5, and the spring accommodating chamber 22 communicates with a master cylinder. Variable anti-lock brake device. 3. The pressure reducing chamber 13 communicates with a wheel cylinder, the pressurizing chamber 12 communicates with a hold valve 5 and a decay valve 6, and the pressure accumulating chamber 21 further includes a discharge port of a hydraulic pump 7 and a hold valve 5. The spring accommodating chamber 22 communicates with the master cylinder, and the brake fluid in the pressurizing chamber 12 is pumped up by the hydraulic pump 7 via the decay valve 6 at the time of depressurization in antilock control to discharge the discharge fluid. The pressure is accumulated in the pressure accumulating chamber 21, and at the time of repressurization, the brake fluid in the pressure accumulating chamber is supplied to the pressurizing chamber 12 via the hold valve 5 so that repressurization can be executed. The variable volume anti-lock brake device described in. 4. The second hydraulic control piston 4 is always maintained in a state in which the volume on the pressure accumulating chamber 21 side is reduced by the urging force of a spring 23 arranged in the spring accommodating chamber. Item 4. A variable volume antilock brake device according to Item 3.