JPH08324402A - Anti-lock hydraulic pressure control device - Google Patents

Abstract

PURPOSE: To dispense with a high pressure accumulator, a pressure switch, a large reservoir tank, or the like to reduce the number of solenoid valves to one per one system, and to provide the fail-safe function when a malfunction is generated in a hydraulic closed circuit. CONSTITUTION: When a malfunction occurs to a closed circuit to communicate an evacuation chamber 13 with an accumulation chamber 17, and the hydraulic pressure in the closed circuit is dropped, a second hydraulic pressure control piston 4 is moved to the left in the figure. A locking can is engaged with a projection 28, and a balance piston 19 is moved to the left to open a first valve 25 and close a second valve 26. When the hydraulic pressure is generated on a master cylinder side in this condition, a first hydraulic pressure control piston 3 is moved to the evacuation chamber 13 side until a check valve 21 is in the closed condition, and the hydraulic pressure from the master cylinder is fed to a wheel cylinder through a first valve 25 for a spring storing chamber 18 to work the brake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a high pressure accumulator,
The present invention relates to a small, lightweight, and inexpensive volume-variable antilock hydraulic pressure control device that does not require a pressure switch or a large reservoir tank. In particular, a failure occurs in the hydraulic pressure closed circuit in the antilock control device. The present invention relates to an anti-lock hydraulic pressure control device that can secure a normal hydraulic pressure passage even in the case of an accident.

[0002]

2. Description of the Related Art Conventionally, a variable volume type is known as a type of antilock hydraulic pressure control device. As an example, the one described in Japanese Utility Model Publication No. 5-467 will be described. This device has a cut valve for shutting off the main fluid passage in the middle of the main fluid passage connecting the master cylinder and the wheel cylinder. A hydraulic control piston is slidably provided in a hydraulic control housing provided closer to the wheel cylinder, and a first hydraulic chamber communicating with the wheel cylinder and the cut valve is provided inside the hydraulic control housing by the hydraulic control piston. The second, which is disconnected from the first hydraulic chamber
It is divided into a hydraulic chamber. 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. I am trying.

[0003]

However, in the variable volume type antilock hydraulic pressure control 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. Also, two electromagnetic valves for control are required for each system, and the accumulators and pressure switches used are expensive, so that the cost of the device is increased. Therefore, the present invention provides a high-pressure accumulator, a pressure switch, and a variable-volume antilock hydraulic pressure control device.
It eliminates the need for large reservoir tanks and reduces the number of control solenoid valves to one per system.
Another object of the present invention is to provide a novel anti-lock hydraulic pressure control device having a fail-safe function when a failure occurs in the hydraulic pressure closed circuit, and to solve the above problems.

[0004]

Therefore, the technical solution adopted by the present invention is a volume-variable type anti-lock brake device, which comprises a first hydraulic pressure for partitioning the expansion chamber 14 and the decompression chamber 13. The control piston 3, the second hydraulic pressure control piston 4 which defines the pressure accumulating chamber 17 and the spring accommodating chamber 18 communicating with the master cylinder, the expansion chamber 14 and the spring accommodating chamber 18 are always communicated with each other, and It has a check valve 21 that communicates or does not communicate in accordance with the lock control mode, and communicates the expansion chamber 14 and the wheel cylinder when normal, and a second valve 26 that disconnects the communication when abnormal, and the wheel cylinder only when abnormal. A balance piston 19 having a first valve communicating with the spring accommodating chamber 18, and the decompression chamber 13 includes a decay valve 6
Further, the pressure accumulating chamber 17 communicates with the discharge port of the hydraulic pump 7 and also communicates with the decay valve 6 through the orifice 5, so that the brake fluid in the pressure reducing chamber 13 decays during depressurization of the antilock control. The brake fluid in the wheel cylinder is pumped up by the hydraulic pump 7 through the valve 6 and the discharged fluid is accumulated in the pressure accumulating chamber 21, and the brake fluid in the wheel cylinder is flown into the expansion chamber. A variable volume type antilock hydraulic pressure control device is characterized in that the brake fluid in the expansion chamber is supplied to the depressurization chamber 13 via the to recirculate to the wheel cylinder so that repressurization can be executed.

[0005]

When the failure occurs in the closed circuit that connects the decompression chamber 13 and the pressure accumulating chamber 17 and the hydraulic pressure in the closed circuit decreases, the second hydraulic control piston 4 is actuated by the spring 31 in the spring collecting chamber 18. Move to the left in the figure. Then, the protrusion 2 between the locking rod 27 of the second hydraulic pressure control piston 4 and the balance piston.
8, the balance piston 19 is moved to the left in the drawing to open the first valve 25 and close the second valve 26. When hydraulic pressure is generated on the master cylinder side in this state, the hydraulic pressure flows into the expansion chamber via the flow path 20 and the check valve 21, and the first hydraulic pressure control piston causes the check valve 21 to move.
Is moved to the decompression chamber 13 side until it is closed, and then the hydraulic pressure from the master cylinder is supplied to the wheel cylinder through the same flow path 20 → hole 24 → first valve 25 to actuate the brake. As described above, even if a failure occurs in the closed circuit, the brake can be surely operated, so that the safety is enhanced.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of an antilock hydraulic pressure control device according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the same device in a normal state, and FIG. 3 is an enlarged sectional view of the same device during antilock control. FIG. 4 is an enlarged cross-sectional view of the same device in a state where the hydraulic closed circuit has a failure. The figure shows a brake piping system that connects the master cylinder and one wheel cylinder, and the piping systems of the 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 an orifice, and 6 is a decay valve. , 7 is a hydraulic pump, 8 is a reservoir, and 10 is a hydraulic control housing.

A large diameter first cylinder portion 11 and a second cylinder portion 12 are formed at both ends of the hydraulic control housing 10. The first hydraulic control piston 3 is provided in the first cylinder portion 11.
Is slidably arranged and a plug 15 is attached to an end thereof, and the inside of the cylinder 11 is divided into a decompression chamber 13 and an expansion chamber 14 by the first hydraulic pressure control piston 3. Further, the second hydraulic pressure control piston 4 is slidably arranged in the second cylinder portion 12, and a plug 16 is attached to an end portion thereof. It is divided into a chamber 17 and a spring collecting chamber 18.

A balance piston 19 is disposed between the first hydraulic pressure control piston 3 and the second hydraulic pressure control piston 4 so as to be slidable with respect to the housing and slidably.
This balance piston 19 has a spring collecting chamber 18
A flow path 20 is formed to connect the expansion chamber 19 and the expansion chamber 19.
A check valve 21 is arranged in this flow passage, and when the check valve 21 bends a spring 23 and the locking bar 22 is in contact with the first hydraulic control piston 3, the check valve 21 is provided. Is opened. When the first hydraulic pressure control piston 3 moves to the pressure reducing chamber 13 side and the expansion chamber 14 is expanded, the locking rod 22 of the check valve 21 separates from the first hydraulic pressure control piston 3, so that the spring The check valve 21 is closed by the urging force of 23, and the balance piston 19
The flow path 20 inside is closed.

A hole 24 is communicated with the flow passage 20, and the hole 24 is communicated with the connection port 2 with the wheel cylinder via a first valve 25 formed between the balance piston 19 and the housing. . The first valve 25 is normally in a closed state, and when the balance piston 19 moves to the left in the figure, the valve communicates the opening hole 24 with the connection port of the wheel cylinder. The expansion chamber 14 communicates with the connection port 2 of the wheel cylinder via a space formed between the outer periphery of the balance piston 19 and the housing 10 and the second valve 26. The second valve 26 is normally open, and when the balance piston 19 moves to the left in the figure, it closes, and the second valve closes, which has the function of disconnecting the communication between the expansion chamber 14 and the connection port 2.

Further, a spring 31 for urging the second hydraulic pressure control piston 4 is arranged in the spring collecting chamber 18, and the collecting chamber 18 is connected to the master cylinder through the connection port 1.
Further, in the spring collecting chamber 18, the balance piston 19 has a protrusion 28 that engages with a locking bar 27 provided on the second hydraulic pressure control piston 4. When the second hydraulic pressure control piston 4 moves to the left and the locking bar 27 engages with the protrusion 28 of the balance piston 19, the balance piston 19 moves to the left in the figure, opening the first valve 25, The second valve 26 is adapted to be closed. 30
Is a spring provided between the second hydraulic pressure control piston 4 and the balance piston 19.

The decompression chamber 13 communicates with the reservoir 8 via the decay valve 6, and the reservoir 8 communicates with the suction port of the hydraulic pump 7. Further, the pressure accumulating chamber 17 is the hydraulic pump 7
And the decay valve 6 through the orifice 5. As is well known, the hydraulic pump 7 can pump the brake fluid from the reservoir 8 or the decompression chamber 13 by operating the pump 7 during antilock control. The operation of the hydraulic pump and the opening / closing timing of the decay valve during the antilock control have been conventionally known, and are not a feature of the present invention, so a detailed description thereof will be omitted here.

The operation of the antilock hydraulic pressure control 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 piston 4 maintains the state shown in FIGS. 1 and 2. Therefore, the check valve 21 is opened, the spring storage chamber 18 and the expansion chamber 14 are communicated with each other, and the expansion chamber 14 is communicated with the wheel cylinder via the second valve 26 that is open. Further, in this state, the pressure accumulating chamber 17 and the pressure reducing chamber 13 are filled with the brake fluid pressure having a predetermined fluid pressure, and the state of FIG. 1 is maintained. Therefore, the brake fluid pressure generated in the master cylinder is passed through the connection port 1 → the spring accommodating chamber 18 → the flow passage 20 in the balance piston → the open check valve 21 → the expansion chamber 14 → the open second valve 26. Is supplied to the wheel cylinder, and the brake is activated. 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 a locked state during brake operation, a detection device (not shown) detects the locking of the wheels, and the electronic control device operates the decay valve 6 and the hydraulic pump 7. That is, when the wheels are locked, the decay valve 6 opens and the hydraulic pump 7 operates. Then, the brake fluid in the decompression chamber 13 partitioned by the first hydraulic pressure control piston 3 flows out to the reservoir 8 via the open decay valve 6, while the hydraulic pressure from the wheel cylinder passes through the second valve 26. Through expansion chamber 1
4, the brake hydraulic pressure is reduced while moving the first hydraulic pressure control piston 3 to the right as shown in FIG. First
The check valve 21 is closed by the movement of the hydraulic pressure control piston 3, and the communication between the spring collection chamber 18 and the expansion chamber 14 is cut off.

A hydraulic pump 7 which operates at substantially the same time as this
As a result, the brake fluid in the reservoir 8 is pumped up and flows into the pressure accumulation chamber 17 defined by the second hydraulic pressure control piston 4. When the brake fluid flows into the pressure accumulating chamber 17, the second
The hydraulic pressure control piston 4 moves against the urging force of the spring 31 and circulates the brake fluid in the spring accommodating chamber 18 to the master cylinder. As described above, the pressure reduction of the wheel cylinder during the anti-lock control is performed by the movement of the first hydraulic pressure control piston 3 to increase the volume of the expansion chamber 14. At this time, a part of the brake fluid discharged from the hydraulic pump 7 passes through the orifice 5 and the decay valve 6
→ Although it recirculates to the reservoir 8, since the amount of recirculating brake fluid is small, the effect on the amount of brake fluid supplied to the pressure accumulating chamber 17 can be ignored.

Repressurization during antilock control is executed as follows. Decay valve 6 when re-pressurizing
Is closed, but the hydraulic pump 7 is still operating in this state. However, since the decay valve 6 is closed and the hydraulic pump 7 is idling and the discharge pressure is lost, the second hydraulic control piston 4 moves to the left in FIG. 3 due to the hydraulic pressure of the master cylinder and the biasing force of the spring 31. As a result, the brake fluid that has flowed into the pressure accumulating chamber 17 becomes
7 → orifice 5 → flows into the pressure reducing chamber 13 defined by the first hydraulic pressure control piston 3, and moves the first hydraulic pressure control piston 3 to the left in the figure. Due to the movement of the piston, the brake fluid that has flowed into the expansion chamber 14 flows back to the wheel cylinder, and the brake is repressurized. During the re-pressurization, the first hydraulic control piston 3 does not move to the left side in the drawing, so the check valve 21 is closed, and the pressure accumulating chamber 17 moves to the depressurizing chamber 13. Since the supplied brake fluid is supplied through the orifice 5, repressurization of the brake is executed slowly.

As described above, in the present invention, the brake fluid pressure is accurately adjusted by changing the volumes of the pressurizing chamber and the depressurizing chamber 13 by the operation of the first hydraulic pressure control piston 3 and the second hydraulic pressure control piston 4. It is possible to control, and the hold valve which has been conventionally required can be eliminated.
In addition, the brake fluid pressure holding state during anti-lock control is
What is executed by controlling the decay valve is the same as the conventional one.

[Failure in Closed Circuit] In the above example, when a failure occurs in the closed circuit that connects the decompression chamber 13 and the pressure accumulating chamber 17, the connection port on the master cylinder side is as follows. 1 and the connection opening 2 on the wheel cylinder side are communicated by the operation of the balance piston 19, so that the hydraulic pressure from the master cylinder can be directly supplied to the wheel cylinder. That is, when the hydraulic pressure in the closed circuit decreases, the second hydraulic pressure control piston 4 moves leftward in the drawing by the spring 31 in the spring collecting chamber 18, as shown in FIG. Then
The locking bar 27 of the second hydraulic pressure control piston 4 and the protrusion 28 of the balance piston are engaged, the balance piston 19 is moved to the left in the drawing, the first valve 25 is opened, and the second valve 26 is closed. When hydraulic pressure is generated on the master cylinder side in this state, this hydraulic pressure is applied to the flow passage 2 in the balance piston.
0 into the expansion chamber 14 and moves the first hydraulic pressure control piston to the pressure reducing chamber 13 side until the check valve 21 is closed, and then the hydraulic pressure from the master cylinder is changed to the spring collecting chamber 18 → Flow path 20 in balance piston → hole 24
→ The brake is supplied to the wheel cylinder via the first valve 25. As described above, in this device, even if a failure occurs in the closed circuit, the brake can be reliably operated, so that the safety is high.

[0019]

As described above in detail, in the variable volume type antilock hydraulic pressure control device of the present invention, a high pressure accumulator, a pressure switch for monitoring the pressure of the antilock hydraulic pressure control device, and Since the reservoir tank for accumulating the brake fluid in the anti-lock control hydraulic circuit is not required, and the hold valve that was required in the past can be eliminated, the overall size and weight of the device can be reduced. Further, since the accumulator, the pressure switch, and the hold valve are unnecessary, the device cost can be reduced. Further, even if a failure occurs in the closed circuit, it is possible to exert an excellent effect such that the brake can be surely operated.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an antilock hydraulic pressure control device according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a normal state of the device.

FIG. 3 is an enlarged cross-sectional view showing a state during antilock control of the device.

FIG. 4 is an enlarged cross-sectional view showing an abnormal state in which a failure occurs in the closed circuit in the same apparatus.

[Explanation of symbols]

 1 Connection Port to Master Cylinder 2 Connection Port to Wheel Cylinder 3 1st Hydraulic Pressure Control Piston 4 2nd Hydraulic Pressure Control Piston 5 Orifice 6 Decay Valve 7 Hydraulic Pump 8 Reservoir 10 Hydraulic Control Housing 11 1st Cylinder 12th 2 cylinders 13 decompression chamber 14 expansion chamber 15, 16 plug 17 accumulator chamber 18 spring collection chamber 19 balance piston 21 check valve 22 locking rod 25 first valve 26 second valve

Claims (4)

[Claims] 1. A variable volume type anti-lock brake device comprising a first hydraulic control piston 3 for partitioning an expansion chamber 14 and a decompression chamber 13, a pressure accommodating chamber 17, and a spring accommodating chamber communicating with a master cylinder. The second hydraulic pressure control piston 4 for partitioning 18 with the expansion chamber 14 and the spring collecting chamber 18 are always in communication with each other, and the check valve 21 is in communication with each other according to the antilock control mode. A balance including a second valve 26 that communicates the expansion chamber 14 and the wheel cylinder in a normal state, and disconnects the same in an abnormal state, and a first valve 25 that communicates the wheel cylinder and the spring accommodating chamber 18 only in an abnormal state. The pressure reducing chamber 13 communicates with the decay valve 6, and the pressure accumulating chamber 17 communicates with the discharge port of the hydraulic pump 7. Is communicated with the decay valve 6 through the orifice 5. When the anti-lock control pressure is reduced, the brake fluid in the decompression chamber 13 is pumped up by the hydraulic pump 7 through the decay valve 6 and the discharge fluid is discharged from the pressure accumulation chamber 21. At the same time, the brake fluid in the wheel cylinder is caused to flow into the expansion chamber, and at the time of repressurization, the brake fluid in the pressure accumulation chamber is supplied to the decompression chamber 13 via the orifice 5 so that the brake fluid in the expansion chamber is returned to the wheel cylinder. A variable volume anti-lock hydraulic pressure control device characterized in that it can perform re-pressurization. 2. The balance piston 19 is the expansion chamber 1
4 is provided with a flow passage 20 that communicates with the spring collecting chamber 18, and a check valve 21 is provided in the flow passage 20. Further, the flow passage 20 is closed through a first valve 25 that is closed in a normal state and opened in an abnormal state. The variable volume type according to claim 1, wherein the expansion chamber 14 is in communication with a wheel cylinder, and further, the expansion chamber 14 is in communication with the wheel cylinder via a second valve 26 provided in the balance piston 19 in a normal state. Anti-lock hydraulic pressure control device. 3. The balance piston 19 comprises a pressure accumulating chamber 17
The first valve 25 is opened and the second valve 26 is closed by the urging force of the spring in the spring accommodating chamber 18 when the hydraulic pressure in the inside disappears. The variable volume anti-lock hydraulic pressure control device described. 4. The check valve 21 is configured to cut off communication between the expansion chamber 14 and the spring collecting chamber 18 when the volume of the expansion chamber 14 expands as the first hydraulic control piston 3 moves. The variable volume antilock hydraulic pressure control device according to claim 2, wherein