JPH09226554A - Braking force control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of suction noise of an electrically-driven pump during the primary check of the pump by opening a changeover valve in response to the pressure difference generated between the first passage between a hydraulic pressure generating device and a valve system and the first passage arranged between a wheel brake cylinder and the valve system or the second passage at the suction side of the pump. SOLUTION: The third valve is a normally-closed valve which is opened in response to the pressure difference generated between the first passage P1 arranged between a tandem master cylinder 10 and and the first valve V1 and the second passage P2 arranged between the second valve V2 and an orifice O1. During the primary check of the electrically-driven pump B, the third valve V3 is kept on closing the third passage P3. Therefore, the pump B does not suck brake fluid contained in the wheel brake cylinder. And furthermore, in case the brake system is activated by a driver during the primary check, generation of suction noise at the pump B is prevented. The solenoid selector valve V4 is closed during the primary check of the pump B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking force control device for a vehicle, and can be applied to, for example, an antilock brake device for a vehicle.

[0002]

2. Description of the Related Art A conventional device of this type is known, for example, from Japanese Patent Application Laid-Open No. 7-2074. This is a hydraulic pressure generator that generates a hydraulic pressure corresponding to the brake operating force, a wheel brake cylinder that receives the hydraulic pressure output from the hydraulic pressure generator to brake the wheels, and a hydraulic pressure generator that is used as a wheel brake cylinder. A first passage connected to the first passage, a normally open valve device arranged in the first passage for opening and closing the first passage, and a wheel brake cylinder connected to the first passage between the hydraulic pressure generator and the valve device without the valve device. A second passage, an electric pump arranged in the second passage so that the suction side is connected to the wheel brake cylinder side, and a discharge side is connected to the hydraulic pressure generator side, and a second passage on the pump suction side. It is provided with a normally-closed type electromagnetic on-off valve that opens and closes it.

Since a normally closed electromagnetic on-off valve is arranged in the second passage on the pump suction side in this device, a primary check of the electric pump (whether the electric pump operates correctly or not is checked in advance). ) At this time, the electric pump can be prevented from sucking the brake fluid in the wheel brake cylinder, and as a result, the suction noise of the pump can be prevented. Further, even when the driver operates the brake during the primary check of the electric pump, it is possible to prevent the suction noise of the pump from being generated.

Further, in this device, when the wheels are about to be locked during braking, the electric pump is operated, the valve device is closed, and the normally closed electromagnetic on-off valve is energized to open. The brake fluid of the wheel brake cylinder is sucked into the electric pump through the second passage on the pump suction side,
The brake fluid pressure in the wheel brake cylinders is being reduced. In other words, in this device, the anti-lock brake control is performed by energizing the normally closed electromagnetic on-off valve to open it.

[0005]

However, in this device, since the solenoid valve is arranged in the second passage on the pump suction side, a solenoid is required, resulting in a disadvantage in cost and an increase in size. There is a problem.

Therefore, according to the present invention, it is possible to prevent the generation of the suction noise of the pump and to perform the antilock brake control at the time of the primary check of the electric pump without installing the solenoid valve in the second passage on the suction side of the pump. This is a technical issue.

[0007]

In order to solve the above technical problems, a vehicle braking force control apparatus according to the invention of claim 1 is a hydraulic pressure generating apparatus for generating a hydraulic pressure corresponding to a brake operating force. A wheel brake cylinder that brakes a wheel by receiving an output hydraulic pressure of the hydraulic pressure generation device; a first passage that connects the hydraulic pressure generation device to the wheel brake cylinder; and a first passage that is disposed in the first passage. A normally open valve device that opens and closes the first passage, a second passage that connects the wheel brake cylinder to the first passage between the hydraulic pressure generating device and the valve device without passing through the valve device, and suction An electric pump disposed in the second passage so that the discharge side is connected to the wheel brake cylinder side and the discharge side is connected to the hydraulic pressure generator side, respectively.
A normally closed on-off valve disposed in the second passage on the pump suction side, wherein the on-off valve includes the first passage between the hydraulic pressure generating device and the valve device, the wheel brake cylinder, and The opening operation is performed based on the differential pressure generated between the first passage between the valve devices or the second passage on the pump suction side.

The operation of the invention of claim 1 will be described below.

Normally, when the driver operates the brake pedal, the hydraulic pressure generating device generates a corresponding broom hydraulic pressure,
It is applied to the wheel brake cylinder via the first passage in which the normally open valve device is present. As a result, the wheels are braked. When the driver releases the brake pedal, the brake fluid pressure in the wheel brake cylinder returns to the fluid pressure generation device via the first passage, so that the brake fluid pressure in the wheel brake cylinder is changed to the fluid pressure in the fluid pressure generation device. It decreases following the pressure.

When the wheels are about to be locked during braking (brake operation), the electric pump is operated and the valve device is closed. At this time, since the valve device is closed, the first passage between the hydraulic pressure generation device and the valve device and the first passage between the wheel brake cylinder and the valve device, and the first passage between the hydraulic pressure generation device and the valve device. A differential pressure is generated between the passage and the second passage on the pump suction side. Therefore, the opening / closing valve is opened by any one of the differential pressures to open the second passage on the suction side. As a result, the brake fluid in the wheel brake cylinder is discharged to the second side of the pump suction side.
It is sucked into the electric pump through the passage and discharged into the first passage between the hydraulic pressure generator and the valve device. As a result, the brake fluid pressure in the wheel brake cylinder is reduced, and the wheel lock can be suppressed.

On the other hand, when the slip ratio of the wheel becomes too small, the valve device is opened. Then, the output hydraulic pressure of the hydraulic pressure generator is applied to the wheel brake cylinders via the first passage. As a result, the brake fluid pressure in the wheel brake cylinder increases, and the braking distance can be shortened. still,
At this time, the electric pump may be operated.

Since the mechanical on-off valve is closed during the primary check of the electric pump, the electric pump does not suck the brake fluid in the wheel brake cylinders, and as a result, the suction noise of the pump is prevented. it can.
Further, even when the driver operates the brake during the primary check of the electric pump, it is possible to prevent the generation of the suction noise of the pump in the same manner.

As described above, according to the first aspect of the invention,
Without installing a solenoid valve in the second passage on the pump suction side,
It is possible to prevent the generation of suction noise of the pump during the primary check of the electric pump, and to reliably perform the pressure reduction control of the anti-skid control.

Here, in the first aspect of the invention, as shown in the second aspect of the invention, the connection between the connection portion of the second passage on the pump discharge side with the first passage and the hydraulic pressure generator is provided. A first opening / closing solenoid valve which is disposed in the first passage and is closed when a brake fluid pressure is applied to the wheel brake cylinder when the brake is not operated; and the first opening / closing solenoid valve between the fluid pressure generator and the first opening / closing solenoid valve. A suction passage for connecting one passage to the second passage between the opening / closing valve and the electric pump, and a normally open type disposed in the suction passage and closed when the wheel brake cylinder is depressurized by the electric pump. It is preferable to further include the second opening / closing solenoid valve.

The operation of the invention of claim 2 will be described below.

When the electric pump is operated and the second opening / closing solenoid valve is closed in the non-braking state, the suction passage connecting the hydraulic pressure generator and the suction side of the electric pump is opened by the normally open first opening / closing solenoid valve. Therefore, the low-pressure brake fluid of the hydraulic pressure generator is sucked by the electric pump through the suction passage and is pressure-fed to the wheel brake cylinder through the first passage where the normally-open valve device is present. At this time, since the connection between the hydraulic pressure generator and the second passage on the pump discharge side is cut off by the second opening / closing solenoid valve, the brake fluid discharged from the electric pump is prevented from flowing out to the hydraulic pressure generator. can do. Further, since the second passage on the pump suction side is closed by the normally closed on-off valve, it is possible to prevent the electric pump from sucking the hydraulic pressure of the wheel brake cylinder. As described above, the hydraulic pressure of the wheel brake cylinder can be reliably increased.

On the other hand, the normally open valve device is closed while the electric pump is operating. At this time, between the first passage between the hydraulic pressure generating device and the valve device and the first passage between the wheel brake cylinder and the valve device, and the first passage between the hydraulic pressure generating device and the valve device and the second passage on the pump suction side. A pressure difference is generated between the passage and the passage. Therefore, the opening / closing valve is opened by any one of the pressure differences to open the second passage on the pump suction side. Then, the flow of the brake fluid discharged from the electric pump to the wheel brake cylinders is blocked, and the brake fluid in the wheel brake cylinders is sucked by the electric pump through the open second suction passage of the pump. . As a result, the hydraulic pressure of the wheel brakes is reduced.

As described above, according to the second aspect, the hydraulic pressure can be reliably applied to the wheel brakes and the hydraulic pressure can be adjusted when the braking operation is not performed. That is, traction control, automatic braking, etc. can be realized.

In order to solve the above technical problems, a vehicle braking force control device according to a third aspect of the present invention is a hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake operating force, and the hydraulic pressure generating device. A wheel brake cylinder that receives the output hydraulic pressure of the device to brake the wheel, a first passage without a throttle that connects the hydraulic pressure generation device to the wheel brake cylinder, and a first passage that are provided in parallel with the first passage. The second passage with a throttle,
A switching valve disposed in the first passage, which normally opens the first passage, closes the first passage during operation, and connects the hydraulic pressure generator to the second passage; A first normally-open type on-off valve arranged in the second passage, and a third connecting the wheel brake cylinder to the first passage between the hydraulic pressure generator and the switching valve without passing through the switching valve. The passage and the suction side to the wheel brake cylinder side,
An electric pump disposed in the third passage so that the discharge side is connected to the hydraulic pressure generator side, and the electric pump disposed in the pump suction side third passage, the hydraulic pressure generator and the valve device Between the first passage between the wheel brake cylinder and the valve device, or any one of the second passage on the throttle downstream side and the third passage on the pump suction side. And a normally-closed second on-off valve that opens based on the differential pressure that occurs in the.

Also in claim 3, similarly to claim 1,
Without installing a solenoid valve in the third passage on the pump suction side,
It is possible to prevent the generation of suction noise of the pump during the primary check of the electric pump, and to reliably perform the pressure reduction control of the anti-skid control.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION A vehicle braking force control device according to an embodiment of this application will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 shows an example in which the wheel brake hydraulic pressure control device according to the first embodiment is applied to an FF-driven vehicle. As shown in the figure, the front left wheel brake cylinder FL and the rear right wheel brake cylinder R
R is a system and is connected to one pressure chamber 10a of a tandem master cylinder (hydraulic pressure generator) 10 with a booster that is operated by a brake pedal 11 by one hydraulic circuit. Also, the front right wheel brake cylinder FR
The left rear wheel brake cylinder RL is a single system, and is connected to the other pressure chamber 10b of the tandem master cylinder 10 by the other hydraulic circuit.

Each hydraulic circuit includes a first passage P1, a second passage P2, a third passage (a second passage of claim 1, a third passage of claim 3) P3, and a fourth passage (claim). The second passage of No. 1 and the third passage of Claim 3) P4. First passage P1
Is a pair of two wheel brake cylinders FL, RR (F) of each pressure chamber 10a (10b) of the master cylinder 10 and one system.
It is a passage without a throttle that connects R, RL). The second passage P2 is provided in parallel with the first passage P1 and has a diaphragm O1. One electric pump B is provided for each of the wheel brake cylinders FL and RR and one system for the wheel brake cylinders FR and RL, and they are simultaneously driven by the drive motor M. This electric pump B
Is to recirculate the hydraulic pressure from each wheel brake cylinder side to the tandem master cylinder side during driving, thereby reducing the hydraulic pressure of each wheel brake cylinder. The third passage P3 includes two wheel brake cylinders FL, R of one system.
The R (FR, RL) is connected to the suction side of the electric pump B. The fourth passage P4 connects the discharge side of the electric pump B to the first passage P1 on the master cylinder 10 side.

In each hydraulic circuit, a valve device A is arranged corresponding to each wheel brake cylinder FL, RR, FR, RL, and each valve device A cooperates with each electric pump B to each wheel. Adjust the hydraulic pressure of the brake cylinders FL, RR, FR, RL. This valve device A includes a first valve (valve device according to claim 1 and a switching valve according to claim 3) V1 and a second valve (claim 3).
First opening / closing valve) V2, a third valve (opening / closing valve of claim 1, second opening / closing valve of claim 3) V3, and a solenoid S. The first valve V1 is disposed in the first passage P1 and normally connects the master cylinder 10 to each wheel brake cylinder via the first passage P1 so as to disconnect the communication during operation and to connect the master cylinder 10 to the second passage. It is a switching valve connected to P2. The first valve V1 is the second valve V2.
Is operated to the operating position (the position to close the first passage), and is held at the operating position when the differential pressure across the throttle O1 in the second passage P2 is equal to or greater than the set value. The second valve V2 is a normally open type on-off valve arranged in the second passage P2 on the upstream side of the throttle. The third valve V3 is a normally-closed type on-off valve disposed in the third passage P3, and outputs the master cylinder output hydraulic pressure (first
Hydraulic pressure in the first passage P1 between the valve V1 and the master cylinder 10 and the second passage P2 between the second valve V2 and the throttle O1.
The opening operation is performed based on the differential pressure generated between the liquid pressure and the liquid pressure. The solenoid S is for opening and closing the second valve V2. The specific configuration of the valve device A will be described later.

Wheel brake cylinders FL, FR, RL,
A check valve C1 is connected in parallel to the first valve V1 corresponding to the RR, and allows only the flow of brake fluid from the front wheel brake cylinders FL, FR side to the pressure chambers 10a, 10b side of the master cylinder 10. . Each third valve V3
In each third passage P3 (intake side of the electric pump) between the electric pump B and the electric pump B, a check valve C2 and a throttle O2 are arranged in order from the third valve side. The check valve C2 blocks backflow from the suction side of the electric pump B to the wheel brake cylinder side. The throttle O2 is for limiting the amount of brake fluid sucked from each wheel brake cylinder via the third passage P3 by the electric pump B, and is used when reducing the brake fluid pressure in both wheel brake cylinders of one system. Moreover, when the liquid pressure difference is large, it is possible to reduce the pressure of both. A damper device D for reducing the discharge pulsation is provided in the fourth passage P4.
A throttle E for reducing the pulsation of the output pressure of the master cylinder 10 is arranged in order from the pump discharge side.

The first passage P1 between the master cylinder 10 and the connecting portion of the fourth passage P4 with the first passage P1 is a normally open which is closed when brake fluid pressure is applied to the wheel brake cylinders when the brakes are not operated. A mold opening / closing solenoid valve (first opening / closing solenoid valve according to claim 2) V5 is provided. Opening / closing solenoid valve V
The first passage P1 between the No. 5 and the master cylinder 10 is connected to the third passage P3 via the suction passage P6. The suction passage P6 is provided with a normally-open solenoid valve (second solenoid valve according to claim 2) V4 that is closed when the wheel brake cylinder is depressurized by the electric pump B.

A check valve C3 for further depression is connected in parallel to each opening / closing solenoid valve V5. The fourth passage P4 is
Each is connected to the master cylinder 10 via a relief valve R. The relief valve R is for releasing the discharge pressure of the electric pump B to the master cylinder 10 when the discharge pressure exceeds an upper limit value. Incidentally, reference numeral P / V in FIG. 1 indicates a well-known proportioning valve.

Here, the valve device A described above with reference to FIG.
The specific configuration of will be described.

As shown in the figure, the first valve V1 and the second valve V1
The valve V2 and the third valve V3 are coaxially assembled together with the solenoid S in the single body 20.

The first valve V1 has a valve seat 31 fixed to the body 20 in a liquid-tight manner and fixed to the body 20, a spherical valve portion 32a detachable from the valve seat 31, and a valve body 32 having the above-mentioned throttle O1.
And a spring 33 that biases the valve element 32 in a direction away from the valve seat 31. The valve body 32 receives the differential pressure across the throttle O1 against the spring 33, respectively. This first valve V1 normally has the first passage P1.
And the spherical valve portion 32a of the valve element 32 is seated on the valve seat 31 to close the first passage P1.

The second valve V2 is provided with a valve seat 32c provided coaxially with the valve body 32, and a rod 34 having a spherical valve portion 34a detachably attached to the valve seat 32c. Therefore, the first passage P2 is opened when the spherical valve portion 34a is separated from the valve seat 32c, and the first passage P2 is closed when the spherical valve portion 34a is seated on the valve seat 32c.

The third valve V3 is provided with a valve seat 20a formed on the body 20, a cylindrical valve body 35 which is removable from the valve seat 20a, and a direction in which the valve body 35 is seated on the valve seat 20a. And a spring 36 for urging. Valve body 35
Is slidably arranged around the valve body 32, and has a hydraulic pressure in the first passage P1 between the master cylinder 10 and the first valve V1 and a hydraulic pressure in the second passage P2 between the second valve V2 and the throttle O1. The pressure difference between the spring 36 and the spring 36 is received against the spring 36. That is, the hydraulic pressure in the first passage P1 between the master cylinder 10 and the first valve V1 is supplied to the pressure chamber 37 via the communication passage 31a formed in the valve seat 31 of the first valve V1. A rubber seal ring 38 is disposed in the pressure chamber 37 to liquid-tightly seal the inner peripheral side and the outer peripheral side.
That is, the valve body 35 is connected to the pressure chamber 3 via the seal ring 38.
Receives fluid pressure of 7. On the other hand, the second valve V2 and the diaphragm O1
The hydraulic pressure in the second passage P2 between the springs 36 passes through the clearance 39 formed between the valve body 32 and the rod 34, and
Is supplied to a pressure chamber 40 that accommodates. That is, the valve element 35 receives the hydraulic pressure of the pressure chamber 40.

The third passage P3 is closed when the valve body 35 is seated on the valve seat 20a, and the third passage P3 is formed between the valve body 35 and the valve seat 20a when the valve body 35 is separated from the valve seat 20a.
The passage P3 is designed to open. A seal ring 41 is arranged between the valve body 35 and the body 20 at the outer periphery of the upper portion of FIG. 2 to seal the outer peripheral side. On the inner circumference of the valve body 35,
The valve body 32 includes the seal ring 42 and the slide resin ring 4.
It is assembled so as to be slidable in a liquid-tight manner via 3.

The solenoid V2 is a first and second valve V
1, the first storage hole 2 of the body 20 so as to be coaxial with V2.
1, a cylindrical stator 51 and a one-end closed sleeve 52 fixed to the stator 1, and a mover 53 provided inside the sleeve 52 so as to face the stator 51 and movable in the opposite direction with respect to the stator 51. A spring 54 that urges the mover 53 in a direction away from the stator 51, and an electromagnetic coil 56 that is coaxially fitted to the outer periphery of the sleeve 52 and fixed by a clip 55 so as not to come off. Here, the upper end of the rod 34 of the second valve V2 is press-fitted and fixed to the mover 53. Therefore, when the electromagnetic coil 56 is energized in the state shown in FIG. 2, the electromagnetic force generated between the stator 51 and the mover 53 moves the mover 53 and the rod 34 downward in the drawing, and the spherical valve portion 34a opens the valve. After sitting on the seat 32b and closing the second passage P2, the first passage P1 is closed by moving integrally with the valve body 32 against the spring 33.

The operation of the vehicle braking force control device constructed as described above will be described below.

When the tandem master cylinder 10 is not operated and the solenoid S and the electric pump B of each valve device A are inoperative, the first valve V1, the second valve V2 and the third valve device A of each valve device A are not operated. The valves V3 are all in the normal state, the first and third passages P1 and P3 are open, and the second passage P2 is closed. When the driver operates the brake pedal 11 and operates the master cylinder 10 in this state (non-braking state), the brake fluid is released through the first passage P1 having no throttle, which is opened by the first valve V1. Master cylinder 1
The pressure is immediately sent from 0 to the wheel brake cylinders FL, RR, FR, RL. When the driver releases the brake pedal 11, the brake fluid in the wheel brake cylinder returns to the master cylinder 10 through the normally open solenoid valve V5.

Further, in a state where the brake fluid is being pumped from the tandem master cylinder 10 to the wheel brake cylinders FL, RR, FR, RL through the first passage P1, the electric pump B is not operated and the solenoid of the valve device A is operated. When the second valve V2 is closed by S, the valve body 32 of the first valve V1 is closed via the rod 34 of the second valve V2 and seated on the valve seat 31 to close the first passage P1. .
That is, since the first passage P1 is closed by the first valve V1 while the second passage P2 is closed by the second valve V2, the tandem master cylinder 10 moves to the wheel brake cylinders FL, RR, FR, RL. The brake fluid is stopped from being pumped to the wheel brake cylinders and the increase in hydraulic pressure at the wheel brake cylinders is stopped. In this stopped state of increase in hydraulic pressure, the first valve V
1 closes the first passage P1 and the second valve V2 closes the second passage P2, the hydraulic pressure (relatively large) in the first passage P1 between the master cylinder 10 and the first valve V1 and the second A differential pressure is generated between the valve V2 and the hydraulic pressure (relatively small) in the second passage P2 between the throttle O1. As a result, the valve element 35 of the third valve V3 is separated from the valve seat 20a against the spring 36, and the third passage P3 is opened. Further, in this state, since the brake fluid does not flow in the second passage P2, no differential pressure is generated before and after the throttle O1 in the second passage P2.

When the electric pump B is operated with the hydraulic pressure stopped, the wheel brake cylinders FL, RR,
Since brake fluid is sucked from the FR and RL to the electric pump B through the third passage P3 in the open state and discharged to the tandem master cylinder 10 side, the wheel brake cylinders FL,
The hydraulic pressure of RR, FR, RL decreases. At this time, the opening / closing solenoid valve V4 is closed to prevent the pressure reducing performance from deteriorating. The liquid pressure reduction state is stopped by stopping the electric pump B.

Further, when the second valve V2 is opened by stopping the energization of the solenoid S while the hydraulic pressure is reduced (the electric pump is operated), the second passage P having the throttle O1 is formed.
2 is opened, the wheel brake cylinders FL, RR, from the tandem master cylinder 10 are passed through the second passage P2.
The brake fluid is squeezed to FR and RL in a throttled state, and the fluid pressures of the wheel brake cylinders FL, RR, FR and RL gradually increase. At this time, since the brake fluid flows through the second passage P2 having the throttle O1, the differential pressure across the throttle O1 becomes equal to or higher than the set value, and the first valve V1 is held in the state where the first passage P1 is closed. At the same time, the hydraulic pressure in the first passage P1 between the master cylinder 10 and the first valve V1 becomes substantially equal to the hydraulic pressure in the second passage P2 between the second valve V2 and the throttle O1, and there is a difference between them. No pressure is generated.
As a result, the valve element 35 of the third valve V3 is seated on the valve seat 20a by the spring 36, and the third passage P3 is closed.

Therefore, when the hydraulic pressure of one wheel brake cylinder (for example, FL) of one system gradually rises, the brake fluid is sucked into the electric pump B from the other wheel brake cylinder (for example, RR). When the hydraulic pressure of the cylinder decreases, the third passage P3 corresponding to the wheel brake cylinder whose hydraulic pressure increases is closed, so that the hydraulic pressure increases from the wheel brake cylinder FL to the third passage P3.
The brake fluid is suppressed from being sucked into the electric pump B via the electric pump B, and the hydraulic pressure of the wheel brake cylinder RR whose hydraulic pressure decreases is accurately reduced by the electric pump B.

In the non-braking state (the first to third valves are in the normal state and the solenoid is not operating), the second valve is used as described above.
The passage P2 is opened. Then, the first valve V1 is held in the closed state of the first passage P1 by the differential pressure across the throttle O1, and the third valve V3 is closed by the spring 36. In this state, when the opening / closing solenoid valve V5 is closed while the electric pump B is driven, the master cylinder 10 is connected to the electric pump suction side through the suction passage P6 by the normally open type opening / closing solenoid valve V4. , The low pressure brake fluid of the master cylinder 10 is sucked by the electric pump B,
It is pressure-fed to the wheel brake cylinders via the fourth passage P4 and the second passage P2 having a throttle. At this time, the opening / closing solenoid valve V5 can prevent the brake fluid discharged from the electric pump B from flowing out to the master cylinder 10. Further, since the third passage P3 is closed by the third valve V3, it is possible to prevent the electric pump B from sucking the hydraulic pressure of the wheel brake cylinder. As a result, the hydraulic pressure of the wheel brake cylinder can be reliably increased.

On the other hand, while the electric pump B is driven, the solenoid S is operated to operate the second passage P2 and the first passage P1.
Is closed, the first passage P1 between the master cylinder 10 and the first valve V1 and the second passage between the second valve V2 and the throttle O1 are closed.
The third valve V3 is opened by the pressure difference generated between the third valve V3 and the passage P2, and the third passage P3 is opened. Then, electric pump B
The flow of the more discharged brake fluid to the wheel brake cylinder is blocked, and the brake fluid in the wheel brake cylinder is sucked by the electric pump B through the third passage P3. As a result, the hydraulic pressure in the wheel brake cylinder is reduced. Here, the opening / closing solenoid valve V4 is closed so as not to deteriorate the pressure reducing performance.

As described above, the hydraulic pressure can be reliably applied to the wheel brakes when the braking operation is not performed, and the hydraulic pressure can be adjusted. That is, traction control, automatic braking, etc. can be realized.

During the primary check of the electric pump B, the normally closed third valve V3 closes the third passage P3, so that the electric pump B does not suck the brake fluid in the wheel brake cylinder. It is possible to prevent the suction noise of the pump B from being generated. Further, even when the driver operates the brake during the primary check of the electric pump B, it is possible to similarly prevent the generation of the suction noise of the pump. During the primary check of the electric pump B, the suction noise of the pump can be prevented by closing the opening / closing solenoid valve V4.

As described above, in the first embodiment, the third valve V3 is the first passage P1 between the master cylinder 10 and the first valve V1, the second valve V2 and the throttle O.
Since it is a normally closed valve that opens based on the pressure difference between the first passage and the second passage P2, it is possible to prevent the generation of suction noise during the primary check of the electric pump B, and to reduce the pressure during antiskid control. The corresponding wheel brake cylinder can be surely communicated with the electric pump B, and further the communication between the wheel brake cylinder and the electric pump can be reliably interrupted when the pressure is increased during the anti-skid control.

(Second Embodiment) In the second embodiment,
It differs from that of the first embodiment in the following points. That is, as shown in FIG. 3, the third valve V3 is opened based on the differential pressure generated between the first passage P1 between the master cylinder 10 and the first valve V1 and the second passage P2 downstream of the throttle O1. A normally closed valve that operates is used, and the check valve C4, the suction passage P6, and the opening / closing solenoid valve V4 (traction control functional component) are eliminated.

(Third Embodiment) In the third embodiment,
It differs from the second embodiment in the following points. That is, as shown in FIG. 4, the third valve V3 is generated between the first passage P1 between the master cylinder 10 and the first valve V1 and the third passage P3 between the third valve V3 and the electric pump B. A normally closed valve that opens based on the differential pressure is used.

In addition to the above-described embodiment, the third
The valve V3 is connected to the master cylinder 10 and the first valve V1.
Between the first passage P1 and the first valve V1 and the first passage P1 between the wheel brake cylinders, the closing operation is performed, or the master cylinder 10 and the first valve V1 are closed.
Between the first passage P1 and the third passage P on the upstream side of the third valve V3.
The closing operation may be performed on the basis of the pressure difference generated between the master cylinder 10 and the wheel brake cylinder.

Further, the opening / closing solenoid valve C4 and the suction passage P of FIG.
6 and the opening / closing solenoid valve V4, a three-port two-position switching valve that connects the master cylinder 10 to the first valve V1 during normal operation, disconnects the connection during operation, and connects the master cylinder 10 to the third passage P3. It may be provided.

The wheel brake hydraulic pressure control device of this embodiment can also be applied to FR-driven automobiles.

[0051]

According to the first and third aspects of the present invention, the suction noise of the pump can be prevented from occurring during the primary check of the electric pump without installing a solenoid valve in the pump suction side passage, and the antiskid can be prevented. It is possible to reliably perform the pressure reduction control of the control.

According to the second aspect of the present invention, the hydraulic pressure can be applied to the wheel brake cylinders and adjusted when the brakes are not operated. As a result, traction control, automatic brake control, etc. can be realized.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle braking force control device according to a first embodiment of the present invention.

2 is a detailed cross-sectional view of the valve device of FIG.

FIG. 3 is an overall configuration diagram of a vehicle braking force control device according to a second embodiment of the present invention.

FIG. 4 is an overall configuration diagram of a vehicle braking force control device according to a third embodiment of the present invention.

[Explanation of symbols]

10 tandem master cylinder (hydraulic pressure generation device) 11 brake pedals FL, RR, FR, RL wheel brake cylinder B electric pump P1 first passage P2 second passage P3 third passage (second passage of claim 1, claim 3) The third
Passage P4 Fourth passage (Second passage of claim 1, Third passage of claim 3)
Passage P6 suction passage A valve device V1 first valve (valve device of claim 1, switching valve of claim 3) V2 second valve (first opening / closing valve of claim 3) V3 third valve (claim 1) On-off valve, second of claim 3
Open / close valve) O1 throttle V5 open / close solenoid valve (first open / close solenoid valve in claim 2) V4 open / close solenoid valve (second open / close solenoid valve in claim 2)

Claims (3)

[Claims] 1. A hydraulic pressure generator for generating a hydraulic pressure corresponding to a brake operating force, a wheel brake cylinder for braking a wheel by receiving an output hydraulic pressure of the hydraulic pressure generator, and the hydraulic pressure generator A first passage connected to a wheel brake cylinder, a normally open valve device arranged in the first passage to open and close the first passage, and the hydraulic pressure generation without the wheel brake cylinder via the valve device. A second passage connected to the first passage between the device and the valve device; and a second passage arranged so that the suction side is connected to the wheel brake cylinder side and the discharge side is connected to the hydraulic pressure generator side. A braking force control device for a vehicle, comprising: an electric pump; and a normally-closed on-off valve disposed in the second passage on the pump suction side, wherein the on-off valve includes the hydraulic pressure generator and the valve. The first passage between the devices and Serial vehicle braking force control apparatus is for opening operation on the basis of the pressure difference generated between the wheel brake cylinder and said first passage or the second passage of the pump suction side between the valve device. 2. The wheel according to claim 1, wherein the second passage on the pump discharge side is disposed in the first passage between the connection portion with the first passage and the hydraulic pressure generator, and the wheel is not operated when the brake is not operated. A first opening / closing solenoid valve that closes when a brake fluid pressure is applied to the brake cylinder; and the first opening / closing solenoid valve between the fluid pressure generator and the first opening / closing solenoid valve.
An intake passage for connecting the passage to the second passage between the on-off valve and the electric pump, and a normally-open type which is disposed in the intake passage and closes when the wheel brake cylinder is depressurized by the electric pump. Second
A braking force control device for a vehicle, further comprising an opening / closing solenoid valve. 3. A hydraulic pressure generator that generates hydraulic pressure corresponding to a brake operating force, a wheel brake cylinder that brakes a wheel by receiving output hydraulic pressure of the hydraulic pressure generator, and the hydraulic pressure generator described above. A first passage having no throttle connected to a wheel brake cylinder, a second passage having a throttle provided in parallel with the first passage, and a first passage arranged in the first passage, which is normally the first passage. And a switching valve that closes the first passage and connects the hydraulic pressure generating device to the second passage during operation, and a normally-open type first valve disposed in the second passage upstream of the throttle. An on-off valve, a third passage connecting the wheel brake cylinder to the first passage between the hydraulic pressure generator and the switching valve without passing through the switching valve, an intake side on the wheel brake cylinder side, and a discharge side on the discharge side. Connected to the hydraulic pressure generator side respectively And an electric pump disposed in the third passage so that the first passage between the hydraulic pressure generating device and the valve device is disposed in the third passage on the pump suction side, the wheel brake cylinder, and Any one of the first passage between the valve devices, the second passage on the wheel brake cylinder side of the first opening / closing valve, and the third passage on the pump suction side.
A braking force control device for a vehicle, comprising a normally-closed second opening / closing valve that opens based on a pressure difference generated between the second opening and the closing valve.