JP3330161B2 - Vehicle brake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system for a vehicle having an anti-skid control function for preventing wheels from locking during braking.

[0002]

2. Description of the Related Art Conventionally, as shown in Japanese Patent Application Laid-Open No. 3-79460, for example, in an anti-skid control device provided with a control valve for controlling brake pressure during braking to prevent locking of wheels, the brake pressure is controlled in advance. Proportioning valve that reduces the pressure increase rate of the rear wheel at a fixed ratio with respect to the front wheel when it exceeds the set operation start pressure is provided, and when sudden braking is performed, the rear of the vehicle body rises up There has been known one that can surely prevent locking of a rear wheel.

[0003]

When the proportioning valve for suppressing the increase in the rear wheel brake pressure is provided as described above, the rear wheel brake pressure is set lower than the front wheel brake pressure. Therefore, there is a problem that the braking force of the rear wheel cannot be utilized to the maximum. Further, since the brake pressure controlled by the control valve provided for executing the anti-skid control of the rear wheel is supplied to the braking portion of the rear wheel via the proportioning valve, the case where the proportioning valve is not provided However, there is a problem that the responsiveness of the supply / discharge control of the brake pressure is poor as compared with the above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. A proportional valve is provided to suppress the locking of the rear wheels, to maximize the braking force of the rear wheels, and to reduce the brake pressure. It is an object of the present invention to provide a vehicle brake device that can prevent a decrease in responsiveness of supply / discharge control.

[0005]

The invention according to claim 1 is
In a vehicle brake device having an anti-skid control function for preventing wheels from locking during braking, a proportioning valve that regulates a brake pressure supplied from a master cylinder to a braking portion of a rear wheel, and adjusts a brake pressure of each wheel. A control valve and an ABS pump for recirculating the brake pressure to the master cylinder side when the brake pressure is reduced, disposing the proportioning valve upstream of the control valve,
A communication path communicating with the discharge port of the pump is connected to a downstream portion of the proportional valve, and a blocking position for preventing the brake pressure from being supplied from the proportional valve to the braking portion of the rear wheel, and a brake pressure supply. A plunger that slides between a permissible position and an allowable position is provided in a proportional valve, and a check valve that closes a communication passage communicating with a discharge part of an ABS pump is provided at a tip end of the plunger.

According to a second aspect of the present invention, the plunger of the proportioning valve is provided with an orifice for restricting the outflow of brake pressure to the master cylinder.

According to a third aspect of the present invention, there is provided an urging member for urging a check valve slidably provided at a tip of a plunger of a proportioning valve in a closing direction, and a brake pressure supply permitting the plunger. And a biasing member for biasing the position, wherein the biasing force of the biasing member for the check valve is set to be smaller than the biasing force of the biasing member for the plunger.

[0008]

According to the first aspect of the present invention, when the front wheel shifts to the anti-skid control state and its brake pressure is reduced, the brake pressure sucked by the ABS pump is applied to the rear wheel via the proportional valve. Supplied to the side. As a result, the braking pressure of the rear wheels can be increased during braking, and the rear wheels can be quickly shifted to the anti-skid control state, so that the braking force can be utilized to the maximum, and At the time of maintenance and inspection of the brake device, the installation portion of the ABS pump and the installation portion of the master cylinder and the like located upstream thereof are shut off by the check valve.

According to the second aspect of the present invention, the ABS
The pulsation of the brake pressure discharged from the pump is attenuated by the orifice provided in the plunger.

According to the third aspect of the present invention, the ABS
After the check valve is opened by the brake pressure discharged from the pump and the above-mentioned brake pressure flows into the proportional valve, the plunger slides, and when the plunger slides, the brake pressure discharged from the ABS pump is reduced. The pulsation will be damped by the orifice.

[0011]

1 shows an embodiment of a vehicle brake device according to the present invention provided in a rear wheel drive vehicle. The brake device includes a master cylinder 2 for generating a brake pressure according to the amount of depression of a brake pedal 1, first and second hydraulic circuits 3 and 4 connected to the master cylinder 2, An anti-skid control unit 5 for controlling the brake pressure applied to the braking units of the wheels RL, FR, FL, RR.

In the brake device, the first hydraulic circuit 3 is connected to the right front wheel FR and the left rear wheel RL,
Of the so-called diagonal split system in which the hydraulic circuit 4 is connected to the braking portions of the right rear wheel RR and the left front wheel FL.

The anti-skid control unit 5 includes a normally-open first solenoid on-off valve 6 provided for each wheel,
A normally closed type second solenoid on-off valve 7, a check valve 8 installed in parallel with the first solenoid on-off valve 6,
A proportional valve 9 disposed upstream of the control valve comprising the electromagnetic on-off valves 6 and 7, that is, on the master cylinder 2 side; and a pair of ABS pumps 11 for returning the brake pressure in the reservoir 10 to the master cylinder 2. The discharge part of the ABS pump 11 is connected to the downstream part of the proportional valve 9.

At the time of anti-skid control, the first and second control signals are output in accordance with a control signal output from a controller (not shown).
When the second electromagnetic on-off valves 6 and 7 are opened and closed, the brake pressure supplied to the brake unit of each wheel is reduced, increased, or held, whereby the braking force of each wheel is individually controlled. It is configured to be.

That is, when the first electromagnetic on-off valve 6 is closed and the second electromagnetic on-off valve 7 is open, the brake pressure in the braking portion of each wheel is led out to the reservoir 10. To a reduced pressure state. This reservoir 10
The brake pressure led out is returned to the master cylinder 2 side via the proportional valve 9 by the ABS pump 11 driven by the drive motor 12.

When the first solenoid on-off valve 6 is opened and the second solenoid on-off valve 7 is closed, the brake pressure in the master cylinder 2 is applied to the braking portion of each wheel. When the pressure is supplied and the pressure is increased, and both the electromagnetic valves 6 and 7 are closed, the flow of the brake pressure is prevented and the brake pressure is maintained.

When the brake pressure supplied from the master cylinder 2 at the time of braking becomes equal to or higher than a preset operation start pressure, the proportional valve 9 rotates the rear wheels RL and RR.
The rate of increase of the brake pressure supplied to the braking section of the front wheels FR,
This is to reduce at a fixed ratio to FL.

That is, the proportional valve 9
As shown in FIG. 2, a plunger 14 slidably supported by a casing 13 and a plunger 1
A biasing member 15 comprising a compression spring for biasing the plunger 4 toward its distal end, that is, toward the downstream side located on the first and second solenoid on-off valves 6 and 7 side; Communication passage 16 connected to master cylinder 2 and connected to master cylinder 2
And the rear wheel R connected to the tip end side of the plunger 14.
A second communication passage 17 communicating with the L and RR braking portions;
Normally, the first communication path 16 and the second communication path 17 are maintained in communication with each other via the proportional valve 9.

When the plunger 14 retreats against the urging force of the urging member 15 in accordance with the brake pressure supplied from the master cylinder 2 during braking, as shown in FIG. But the casing 1
3 and comes into contact with a seal member 19 provided in the communication passage 1.
The communication state of the rear wheels R and R is cut off.
The supply of the brake pressure to the brake units L and RR is temporarily stopped, and the increase in the brake pressure of the rear wheels RL and RR is suppressed.

A check valve 20 for closing a third communication passage 21 communicating with a discharge portion of the ABS pump 11 is provided at a tip end of the proportional valve 9. The check valve 20 controls the brake fluid of the master cylinder 2. Is prevented from flowing back to the ABS pump 11 side.

As shown in FIG. 4, the ABS pump 11 has a drive cam 22 installed in a casing 13 and a plan which is driven reciprocally by the drive motor 22 being driven to rotate by the drive motor 12. A jar 23 and the reservoir 1 provided at a suction portion of the plunger 23.
First check valve 24 for preventing backflow of brake pressure to zero
A second check valve 26 provided at a discharge portion of the plunger 23 for preventing the brake pressure from flowing from the proportional valve 9, and a damping chamber 27 for absorbing a pulsation of the discharged brake pressure. I have.

As shown in FIGS. 5 and 6, the casing 13 has a third communication passage 21 for guiding the brake pressure pumped from the reservoir 10 by the ABS pump 12 to a downstream portion of the proportional valve 9. And a second part of which supplies a part thereof to the first on-off valve 6 of the rear wheels RL and RR.
A passage 17 and a first passage 16 for leading the remaining brake pressure to the installation portion in the master cylinder 2 are formed.

In the above configuration, when the brake pedal 1 is depressed and a braking operation is performed, the brake pressure sent from the master cylinder 2 causes the first electromagnetic opening / closing valve 6 from the first and second hydraulic circuits 3 and 4 to operate. And is supplied to the braking section of each wheel. When the brake pressure becomes equal to or higher than the preset operation start pressure, the proportional valve 9 is operated, and the rate of increase of the brake pressure on the rear wheels RL, RR is increased by the front wheels FR,
It will be adjusted so as to be lower than the FL side.

Next, when it is detected that the braking force of the front wheels FR and FL becomes excessive and a locking tendency is generated, the state shifts to an anti-skid control state, and the first solenoid on-off valve 6 is closed. At the same time, when the second electromagnetic on-off valve 7 is opened, the reservoir 1
The brake pressure is derived to 0, and the brake pressure of the front wheels FR and FL is reduced. Further, the brake pressure led to the reservoir 10 at the time of the pressure reduction is sucked by the ABS pump 11 and supplied to the downstream portion of the proportional valve 9.

When the plunger 14 of the proportional valve 9 is retracted in accordance with the brake pressure supplied to the downstream portion of the proportional valve 9, the check valve 20 provided at the tip of the proportional valve 9 is opened. As a result, the brake pressure flows into the proportional valve 9, and a part of the brake pressure flows into the second communication passage 17, and the rest flows out to the first and second hydraulic circuits 3 and 4 via the proportional valve 9. Is returned to the master cylinder 2.

The brake pressure derived from the braking portions of the front wheels FR and FL and flowing into the second communication passage 17 is supplied to the braking portions of the rear wheels RL and RR via the first solenoid valve 6. Thereby, the rear wheels RL and RR are in a pressure increasing state, and the braking force is increased. When the braking force of the rear wheels RL and RR becomes excessive, the rear wheels RL and RR shift to the anti-skid control state at that time.

As described above, the proportioning valve 9 is disposed upstream of the control valve including the first and second solenoid on-off valves 6 and 7, and the discharge port of the ABS pump 11 is connected to the third communication passage 21. Connected to the downstream portion of the proportional valve 9 through the brake valve, so that the brake pressure derived from the braking portions of the front wheels FR and FL during anti-skid control is supplied to the braking portions of the rear wheels RL and RR. The brake pressure of the rear wheels RL, RR can be appropriately increased, and the rear wheels RL, RR can be quickly shifted to the anti-skid control state.
As a result, the braking force of the front and rear wheels RL and RR can be distributed to a state close to ideal, and the braking distance can be greatly reduced.

That is, as shown in FIG. 7, the braking force distribution ratio on the rear wheels RL and RR during braking shifts from the operating pressure point A of the proportional valve 9 to a decreasing state.
At the start pressure point B of the anti-skid control of the front wheels FR and FL, it rapidly increases and reaches a pressure point C (anti-skid start pressure point of the rear wheel) close to the ideal distribution ratio indicated by the dashed line. For this reason, the braking force of the rear wheels RL and RR is utilized to the utmost, and the braking distance of the vehicle is greatly reduced.

Further, since the proportional valve 9 is disposed upstream of the control valve for anti-skid control as described above, as in the case where the proportional valve is disposed downstream of the control valve, the proportional valve 9 is not used. The presence of the brake pressure does not delay the supply timing of the brake pressure, and the responsiveness of the brake pressure control of the rear wheels RL and RR can be improved.

Further, since the brake pressure discharged from the ABS pump 11 is returned to the master cylinder 2 via the proportional valve 9, the proportional valve 9 acts as a shock absorber for absorbing the pulsation of the ABS pump 11, The pulsation is transmitted to the brake pedal 1 via the master cylinder 2 to prevent the driver from feeling uncomfortable. Therefore, by reducing the capacity of the damping chamber 27 provided in the discharge part of the ABS pump 11 or omitting the damping chamber 27, the casing 13 in which the anti-skid control unit 5 is housed can be made compact. it can.

As described above, the check valve 20 is provided at the tip of the proportional valve 9 so that the ABS pump 1
Since the third passage 21 communicating with the first hydraulic circuit 1 is configured to be closed by the check valve 20, the air in the first and second hydraulic circuits 3, 4 is evacuated from the reservoir 10 side during the assembly of the brake device, and the vacuum is removed. In this state, the operation of filling the brake fluid into which the brake pressure flows can be efficiently executed.

That is, when assembling the above-described brake device, the brake pressure is applied to the first and second hydraulic circuits 3 and 4 after the ABS pump 11 filled with the brake fluid and its communication pipe 21 are assembled. Vacuum filling has been performed. Therefore, if the brake fluid inside the damping chamber 27 and the brake fluid flows into the first and second hydraulic circuits 3 and 4 during the air bleeding operation, a sufficient vacuum cannot be obtained, which hinders the operation of filling the brake pressure. However, in the case where the inflow of the brake fluid is prevented by the check valve 20, the operation of charging the brake pressure can be performed easily and reliably.

In the above embodiment, the plunger 14
The example in which the spherical check valve 20 is integrally formed at the tip of the plunger has been described. As shown in FIG.
And a check valve 29 formed of a poppet valve slidably supported at the distal end portion of the proportional passage 9 and a check valve 29 formed of a poppet valve. And a biasing member 30 made of a compression spring for biasing the plunger 14.
May be set smaller than the urging force.

The proportional valve 9 having the above structure is
Normally, the plunger 14 is locked at the lower end position in response to the urging force of the urging member 15 composed of a compression spring, and the check valve 29 conducts the communication passages 16 and 17 and closes the third communication passage 21. It is held in the position that was set.

When the brake pressure becomes equal to or higher than the preset operation start pressure during braking, as shown in FIG. 9, the plunger 14 is retracted against the urging force of the urging member 15, and the plunger 14 Seal material 3 provided at the tip
1 contacts the bulging portion 32 formed in the check valve 29 to close the conduction path 26, and the proportional valve 9
Is activated.

The proportional valve 9 shown in FIG.
When the ABS pump 11 is driven by the drive motor 12 in the non-operating state, the check valve 29 is retracted by the discharge pressure, and the third passage 21 is opened. The brake pressure discharged from the ABS pump 11 flows into a downstream portion of the valve 9, and a part of the brake pressure is supplied to the second communication path 17. Further, the plunger 14 slides up and down in response to the fluctuation of the brake pressure flowing into the proportional valve 9, and the pulsation of the ABS pump 11 is effectively performed by the resistance force of the urging member 15 acting at the time of the slide displacement. Will be absorbed.

On the other hand, when the ABS pump 11 is driven in the operation state of the proportional valve 9 shown in FIG. 9, it is possible to exert the pulsation absorbing action by sliding the plunger 14 as described above. Therefore, in the above-mentioned embodiment, the pulsation of the ABS pump 11 is absorbed by providing an orifice 33 communicating with the conduction path 26 at the rear end of the plunger 14.

That is, the proportional valve 9
In the operating position of the first and second hydraulic circuits 3, 4,
The conduction path 26 and the orifice 33 are arranged such that communication with the opening of the conduction path 26 is cut off and only the orifice 33 communicates with the first and second hydraulic circuits 3 and 4. As a result, the brake pressure flowing into the conduction path 26 in the above state has to pass through the orifice 33,
The pulsation absorbing function is exhibited by the flow resistance acting when the brake pressure passes through the orifice 33.

In the above-described embodiment, an example in which the anti-skid control unit 5 of the 8-valve type in which a pair of electromagnetic on-off valves 6 and 7 are provided for each wheel is described. The structure may be provided with an anti-skid control unit having a flow control valve. Also, it goes without saying that the configuration of the present invention can be applied to a rear-wheel drive vehicle.

[0040]

As described above, according to the present invention, the proportioning valve is disposed upstream of the control valve for anti-skid control, and the communication passage communicating with the discharge port of the ABS pump is provided by the proportional valve. Because it is configured to be connected to the downstream part, the brake pressure derived from the braking part at the time of anti-skid control of the front wheel is supplied to the braking part of the rear wheel via the proportional valve, and the braking force of the rear wheel increases. Then, the rear wheels shift to the anti-skid control state early, so that the distribution of the braking force of the rear wheels can be set to a state close to ideal, and the braking distance can be greatly reduced.

Further, since the proportional valve is disposed upstream of the control valve, the brake pressure supply timing is delayed by the presence of the proportional valve, as in the case where the proportional valve is disposed downstream of the control valve. Thus, the responsiveness of the rear wheel brake pressure control can be improved.

Further, since the brake pressure discharged from the ABS pump is returned to the master cylinder via the proportional valve, the proportional valve acts as a shock absorber for absorbing the pulsation of the ABS pump. And transmitted to the brake pedal to prevent the driver from feeling uncomfortable. Therefore, by reducing the capacity of the damping chamber provided in the discharge part of the ABS pump or omitting the damping chamber, there is an advantage that the casing in which the anti-skid control unit is housed can be made compact. .

[Brief description of the drawings]

FIG. 1 is a piping diagram showing an embodiment of a vehicle brake device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a proportional valve.

FIG. 3 is a sectional view showing an operation state of a proportional valve.

FIG. 4 is a partially cutaway sectional view showing the internal structure of the anti-skid control unit.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a plan view of the anti-skid control unit.

FIG. 7 is a graph showing a braking force distribution state of front and rear wheels.

FIG. 8 is a sectional view showing another example of a proportional valve.

FIG. 9 is a sectional view showing an operation state of the proportional valve.

[Explanation of symbols]

 2 Master Cylinder 9 Proportional Valve 11 ABS Pump 14 Plunger 15 Biasing Member for Plunger 20, 29 Check Valve 21 Communication Path 30 Biasing Member for Check Valve 33 Orifice

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-254407 (JP, A) JP-A-4-151358 (JP, A) JP-A-2-283556 (JP, A) JP-A-3-283 157254 (JP, A) JP-A-1-257652 (JP, A) JP-A-2-31971 (JP, A) JP-A-2-87667 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/26 B60T 8/48

Claims (3)

(57) [Claims] 1. A vehicle brake device having an anti-skid control function for preventing locking of a wheel during braking, a proportioning valve for regulating a brake pressure supplied from a master cylinder to a braking portion of a rear wheel, A control valve for adjusting the brake pressure and an ABS pump for returning the brake pressure to the master cylinder side when the brake pressure is reduced are provided, and the proportioning valve is disposed upstream of the control valve. Connect the communication passage communicating with the discharge port to the downstream of the proportional valve , and
Brake pressure from the positioning valve to the braking part of the rear wheel
Blocking position to prevent supply and supply of brake pressure
Plunge that slides between an allowable position that allows
Is installed on the proportional valve and A
A check for closing the communication passage communicating with the discharge part of the BS pump
A brake device for a vehicle, wherein a brake valve is provided at a tip portion of the plunger . Wherein Proportioner brake system according to claim 1, wherein the outflow of the brake pressure is provided an orifice for restricting the the partitioning valve plunger to the master cylinder. 3. An urging member for urging a check valve provided on a plunger of a proportioning valve in a closing direction, and an urging member for urging the plunger to a brake pressure supply allowable position, the biasing force of the biasing member for the check valve, the vehicular brake system according to claim 1, wherein a is set smaller than the urging force of the urging member for the plunger.