JPH09216549A - Hydraulic pressure control device of wheel brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the sucking in of a brake liquid from a wheel brake cylinder to an electric pump, by making a closing operation of a third valve corresponding to a wheel brake cylinder to raise the hydraulic pressure, by the pressure difference at the front side and the rear side of the throttle of a second passage, so as to close a third passage. SOLUTION: Under the condition operating electric pumps B, the second valves V2 are operated to open, so as to open the second passages P2 having a throttle 01, and a brake liquid is pressurizingly fed in the throttled condition from a tandem master cylinder 10 to wheel brake cylinders FL, RR, FR, and RL through the second passages P2, so as to raise the hydraulic pressures of the wheel brake cylinders FL, RR, FR, and RL. Since the brake liquid flows through the second passages P2 in this case, the third valves V3 are operated to close so as to close the third passages P3, as well as the pressure difference at the front side and the rear side of the throttles 01 is made higher than a set value, so as to maintain the first valves V1 in the condition to close the third passages P3. Thus the sucking in of the brake liquid can be supressed to an electric pump B.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As a conventional device of this type, Japanese Patent Laid-Open No.
The ones disclosed in JP-A-171487 and JP-A-7-2074 are known. The former one is arranged in a hydraulic circuit that has a plurality of wheel brake cylinders as one system, and reduces the hydraulic pressure of each wheel brake cylinder by circulating the hydraulic pressure from each wheel brake cylinder side to the master cylinder side. It is provided with a single electric pump and an electromagnetic valve device which is arranged in a hydraulic circuit corresponding to each wheel brake cylinder and cooperates with the electric pump to adjust the hydraulic pressure of the wheel brake cylinder.

In the latter, an electromagnetic valve device having two valves and one solenoid (having an electromagnetic coil, a mover, etc.) is provided in the passage connecting the master cylinder and the wheel brake cylinder. In addition, an electromagnetic opening / closing valve is arranged in the passage connecting the wheel brake cylinder and the suction side of the electric pump.

[0004]

In the former case, an electromagnetic opening / closing valve having a single valve structure is adopted as each electromagnetic valve device, and each passage connecting the brake cylinder of each wheel and the suction side of the electric pump is provided. Each has a diaphragm,
The device is simply configured. However, in the former one, when there is a large difference in road surface μ (friction coefficient) between the wheels, which are considered as one system, the hydraulic pressure of the high μ side wheel brake cylinder is increased to increase the hydraulic pressure of the low μ side wheel brake cylinder. When the hydraulic pressure is reduced, the hydraulic pressure of the high-μ side wheel brake cylinder increases, so that the flow rate of the brake liquid flowing from the cylinder to the suction side of the electric pump through the throttle increases. Therefore, there arises a problem that the hydraulic pressure in the low μ side wheel brake cylinder cannot be accurately reduced by the electric pump.

The problem is that, like the latter one, a solenoid valve having two valves and one solenoid (one having an electromagnetic coil, a mover, etc.) in the passage connecting the master cylinder and the wheel brake cylinder. This can be solved by arranging the device and arranging the electromagnetic opening / closing valve in the passage connecting the wheel brake cylinder and the suction side of the electric pump. However, in the latter one, since the electromagnetic on-off valve is arranged in the passage connecting the wheel brake cylinder and the suction side of the electric pump, a large solenoid is required to drive it, which is disadvantageous in cost and installation space. In addition to the above, there is a disadvantage in controlling the device (controlling energization of each solenoid).

Therefore, it is a technical object of the present invention to solve the above problems without providing a solenoid valve in a passage connecting each wheel brake cylinder to the suction side of an electric pump.

[0007]

In order to solve the above technical problems, the wheel brake hydraulic pressure control device according to the invention of claim 1 is a hydraulic pressure generation device for generating a hydraulic pressure corresponding to a brake operating force. And a first wheel brake cylinder and a second wheel brake cylinder that receive the output hydraulic pressure of the hydraulic pressure generator to brake the corresponding wheels, and there is no throttle that connects the hydraulic pressure generator to the two wheel brake cylinders. A first passage, a second passage having a throttle provided in parallel with the first passage, and an electric pump for returning hydraulic pressure from the two-wheel brake cylinder side to the hydraulic pressure generator side. A third passage connecting an intake side of the electric pump to each of the wheel brake cylinders, a fourth passage connecting a discharge side of the electric pump to the first passage on the hydraulic pressure generator side, and the first passage. Open aisle A first valve that normally opens the first passage, a second valve that opens and closes the second passage in cooperation with the first valve, and a second valve that normally closes the second passage, and the third passage A valve for adjusting the hydraulic pressure of the wheel brake cylinder in cooperation with the electric pump, the valve having a third valve that normally opens the third passage and a solenoid that operates the second valve. Device,
It is arranged in the first passage between the connection portion of the hydraulic pressure generator and the fourth passage with the first passage, and connects the hydraulic pressure generator and the first valve when not operating, and A switching valve that disconnects the hydraulic pressure generator from the first valve and connects the hydraulic pressure generator to the third passage between the third valve and the electric pump; When the second valve is closed, the first
A valve configured to close the first passage through the second valve to close the first passage, and the first passage and the second passage.
When the second valve is opened by the solenoid with the passage closed, the differential pressure across the throttle becomes equal to or greater than a set value, so that the first valve is held in the closed state. In addition, the third valve is configured to close to close the third passage.

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

When the fluid pressure generating device (that is, the brake pedal) is not operated and the switching valve, the solenoid of each valve device and the electric pump are inactive, the first valve, the second valve and the valve of each valve device are operated. All 3rd valves are in normal condition, 1st
The third passage is open and the second passage is closed. When the hydraulic pressure generator is operated from this state (non-braking state), the first
The brake fluid is immediately pumped from the hydraulic pressure generator to the wheel brake cylinders through the first passage having no throttle which is opened by the valve.

With the brake fluid being pumped from the fluid pressure generator to the wheel brake cylinder through the first passage,
When the electric pump is not operated and the second valve is closed by the solenoid of the valve device, the first valve is set to the second valve.
The valve is closed to close the first passage. That is,
Since the first passage is closed by the first valve while the second passage is closed by the second valve, the pumping of brake fluid from the hydraulic pressure generator to the wheel brake cylinder is stopped, and the wheel brake cylinder is closed. The increase in hydraulic pressure stops at. In this hydraulic pressure increase stop state, since the brake fluid does not flow into the second passage, no differential pressure is generated before and after the throttle of the second passage, and the third valve is kept open to open the third passage. ing.

Further, when the electric pump is operated with the hydraulic pressure stopped, the brake fluid is sucked from the wheel brake cylinder to the electric pump through the open third passage and discharged to the hydraulic pressure generator side. , The hydraulic pressure in the wheel brake cylinder decreases. It should be noted that this liquid pressure reduction state is stopped by stopping the electric pump.

Further, when the second valve is opened by the solenoid in the fluid pressure decreasing state (state where the electric pump is operated), the second passage having the throttle opens, so that the fluid pressure generating device passes through the second passage. The brake fluid is squeezed from the wheel brake cylinder to the wheel brake cylinder, and the hydraulic pressure in the wheel brake cylinder gradually rises. At this time, since the brake fluid flows through the second passage having the throttle, the differential pressure across the throttle becomes equal to or more than the set value, the first valve is held in the state where the first passage is closed, and the third valve is closed. Then, the third passage is closed.

Therefore, the hydraulic pressure of one wheel brake cylinder (for example, the first wheel brake cylinder), which is one system, is gradually increased, and the hydraulic pressure of the other wheel brake cylinder (for example, the second wheel brake cylinder) is increased. In the case of decreasing the hydraulic pressure, since the third passage corresponding to the one wheel brake cylinder in which the hydraulic pressure increases is closed, it is possible to suppress the intake of the brake fluid from the one wheel brake cylinder to the electric pump, The hydraulic pressure of the wheel brake cylinder, which decreases in pressure, is accurately reduced by the electric pump.

Further, in the non-braking state (the first to third valves are in the normal state and the solenoid is not operating), as described above, the second
Open the passage and set the first valve to the first position by the differential pressure across the throttle.
The passage is kept closed and the third valve is closed. In this state, when the electric pump is driven and the switching valve is operated, the switching valve connects the hydraulic pressure generating device to the third passage between the third valve and the electric pump (that is, the suction side of the electric pump). The low-pressure brake fluid of the hydraulic pressure generator is sucked by the electric pump through the switching valve, and is pressure-fed to the wheel brake cylinders through the fourth passage and the second passage having the throttle. At this time, since the connection between the hydraulic pressure generator and the connecting portion of the fourth passage with the first passage is cut off by the switching valve, the brake fluid discharged from the electric pump is prevented from flowing out to the hydraulic pressure generator. Can be prevented. Further, since the third passage closes the third valve, it is possible to prevent the electric pump 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, when the solenoid is operated to close the second passage and the first passage while the electric pump is driven,
The third valve opens to open the third passage. 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 third passage. As a result, the hydraulic pressure of the wheel brakes is reduced.

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.

In order to solve the above technical problems, a wheel brake hydraulic pressure control device according to a second aspect of the present invention includes a hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake operating force, and the hydraulic pressure generating device. A first wheel brake cylinder and a second wheel brake cylinder that brake the corresponding wheels by receiving the output hydraulic pressure of the device; a first passage without a throttle that connects the hydraulic pressure generator to the two wheel brake cylinders; A second passage having a throttle provided in parallel with the first passage, an electric pump for returning hydraulic pressure from the two-wheel brake cylinder side to the hydraulic pressure generator side, and suction of the electric pump A third passage connecting a side to each wheel brake cylinder, a fourth passage connecting a discharge side of the electric pump to the main passage on the hydraulic pressure generator side, and a first passage opened / closed in the normal state. First A first valve that opens the passage, a second valve that opens and closes the second passage in cooperation with the first valve to close the second passage in a normal state, and a second valve that is disposed in the third passage in a normal state A valve device having a third valve for opening the third passage and a solenoid for operating the second valve, the valve device adjusting the hydraulic pressure of the wheel brake cylinder in cooperation with the electric pump; A normally open, which is disposed in the first passage between the generator and the connecting portion of the fourth passage with the first passage, and is closed when the brake fluid pressure is applied to the wheel brake cylinder regardless of the brake operation. Type first on-off valve, and a fifth passage for connecting the first passage between the hydraulic pressure generating device and the first on-off electromagnetic valve to the third passage between the third valve and the electric pump , Arranged in the fifth passage, less And a second opening / closing valve that is opened when the brake fluid pressure is applied to the wheel brake cylinder regardless of the brake operation, and when the second valve is normally closed by the solenoid, the first valve is When the second valve is opened by the solenoid while the first passage and the second passage are closed, the closing operation is performed via the second valve to close the first passage. When the differential pressure across the throttle becomes equal to or greater than the set value, the first valve is held in the state in which the first passage is closed, and the third valve is closed to close the third passage. It is composed.

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

When the hydraulic pressure generating device (that is, the brake pedal) is not operated and the first opening / closing valve, the solenoid of each valve device and the electric pump are inoperative, the first valve of each valve device is not operated.
Valve, second valve and third valve are all in normal condition,
The first and third passages are open and the second passage is closed. When the hydraulic pressure generator is operated in this state (non-braking state),
The brake fluid is immediately pumped from the hydraulic pressure generation device to the wheel brake cylinders through the first passage having no throttle which is opened by the first valve.

With the brake fluid being pumped from the fluid pressure generator to the wheel brake cylinder through the first passage,
When the electric pump is not operated and the second valve is closed by the solenoid of the valve device, the first valve is set to the second valve.
The valve is closed to close the first passage. That is,
Since the first passage is closed by the first valve while the second passage is closed by the second valve, the pumping of brake fluid from the hydraulic pressure generator to the wheel brake cylinder is stopped, and the wheel brake cylinder is closed. The increase in hydraulic pressure stops at. In this hydraulic pressure increase stop state, since the brake fluid does not flow into the second passage, no differential pressure is generated before and after the throttle of the second passage, and the third valve is kept open to open the third passage. ing.

When the electric pump is operated while the hydraulic pressure is stopped, the brake fluid is sucked into the electric pump from the wheel brake cylinder through the open third passage and discharged to the hydraulic pressure generator side. , The hydraulic pressure in the wheel brake cylinder decreases. It should be noted that this liquid pressure reduction state is stopped by stopping the electric pump.

Further, when the second valve is opened by the solenoid in the hydraulic pressure decreasing state (state where the electric pump is operated), the second passage having the throttle opens, so that the hydraulic pressure generating device passes through the second passage. The brake fluid is squeezed from the wheel brake cylinder to the wheel brake cylinder, and the hydraulic pressure in the wheel brake cylinder gradually rises. At this time, since the brake fluid flows through the second passage having the throttle, the differential pressure across the throttle becomes equal to or more than the set value, the first valve is held in the state where the first passage is closed, and the third valve is closed. Then, the third passage is closed.

Therefore, the hydraulic pressure of one wheel brake cylinder (for example, the first wheel brake cylinder), which is one system, is gradually increased, and the hydraulic pressure of the other wheel brake cylinder (for example, the second wheel brake cylinder) is increased. In the case of decreasing the hydraulic pressure, since the third passage corresponding to the one wheel brake cylinder in which the hydraulic pressure increases is closed, it is possible to suppress the intake of the brake fluid from the one wheel brake cylinder to the electric pump, The hydraulic pressure of the wheel brake cylinder, which decreases in pressure, is accurately reduced by the electric pump.

Further, in the non-braking state (the first to third valves are in the normal state and the solenoid is inoperative), the second valve is used as described above.
Open the passage and set the first valve to the first position by the differential pressure across the throttle.
The passage is kept closed and the third valve is closed. In this state, when the electric pump is driven and the first opening / closing valve is closed and the second opening / closing valve is opened,
Since the fifth passage connecting the hydraulic pressure generating device and the third passage between the third valve and the electric pump is opened, the low pressure brake fluid of the hydraulic pressure generating device is sucked by the electric pump through the suction passage, and the fourth passage is formed. And to the wheel brake cylinder via a second passage having a throttle. At this time, since the connection between the hydraulic pressure generator and the connecting portion of the fourth passage with the first passage is disconnected by the first opening / closing valve, the brake fluid discharged from the electric pump flows out to the hydraulic pressure generator. Can be prevented. Further, since the third passage closes the third valve, it is possible to prevent the electric pump 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, when the solenoid is operated to close the second passage and the first passage while the electric pump is driven,
The third valve opens to open the third passage. 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 third passage. As a result, the hydraulic pressure of the wheel brakes is reduced.

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.

In order to solve the above technical problems, a wheel brake hydraulic pressure control device according to a third aspect of the present invention includes a hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake operating force, and the hydraulic pressure generating device. A first wheel brake cylinder and a second wheel brake cylinder that brake the corresponding wheels by receiving the output hydraulic pressure of the device; a first passage without a throttle that connects the hydraulic pressure generator to the two wheel brake cylinders; A second passage having a throttle provided in parallel with the first passage, an electric pump for returning hydraulic pressure from the two-wheel brake cylinder side to the hydraulic pressure generator side, and suction of the electric pump A third passage connecting a side to each wheel brake cylinder, a fourth passage connecting a discharge side of the electric pump to the main passage on the hydraulic pressure generator side, and a first passage opened / closed in the normal state. First A first valve that opens the passage, a second valve that opens and closes the second passage in cooperation with the first valve to close the second passage in a normal state, and a second valve that is disposed in the third passage in a normal state A valve device having a third valve for opening the third passage and a solenoid for operating the second valve, the valve device adjusting the hydraulic pressure of the wheel brake cylinder in cooperation with the electric pump; A check provided in the first passage between the generator and the connecting portion of the fourth passage with the first passage, and allowing only the inflow of brake fluid from the hydraulic pressure generator to the wheel brake cylinder side. A valve, a fifth passage for connecting the first passage between the hydraulic pressure generator and the check valve to the third passage between the third valve and the electric pump, and the fifth passage Less by electric pump A normally open-type on-off valve that closes when one of the wheel brake cylinders is depressurized, and when the second valve is normally closed by the solenoid, the first valve passes through the second valve. When the second valve is opened by the solenoid while the first passage and the second passage are closed, the differential pressure across the throttle is set. When the value is equal to or more than the value, the first valve is held in the state where the first passage is closed, and the third valve is closed to close the third passage.

The operation of the invention of claim 3 will be described below.

When the hydraulic pressure generator (that is, the brake pedal) is not operated and the solenoid and the electric pump of each valve device are inactive, the first valve and the second valve of each valve device are operated.
The valve and the third valve are all in the normal state, and the first and third valves are
The passage is open and the second passage is closed. When the hydraulic pressure generator is operated in this state (non-braking state), the check valve C
The brake fluid is immediately pumped from the hydraulic pressure generation device to the wheel brake cylinder through the first passage having no throttle which is opened by 5 and the first valve.

In this state, when the electric pump is not operated and the second valve is closed by the solenoid of the valve device, the first valve is closed via the second valve to close the first passage. . That is, since the first passage is closed by the first valve while the second passage is closed by the second valve, the pumping of the brake fluid from the hydraulic pressure generator to the wheel brake cylinder is stopped, and the wheel is stopped. The hydraulic pressure stops increasing in the brake cylinder. In this hydraulic pressure increase stop state, since the brake fluid does not flow into the second passage, no differential pressure is generated before and after the throttle of the second passage, and the third valve is kept open to open the third passage. ing.

When the electric pump is operated and the opening / closing valve is closed while the hydraulic pressure is stopped, the brake fluid is sucked from the wheel brake cylinder to the electric pump through the open third passage to generate the hydraulic pressure. It is discharged to the device side. Here, since the on-off valve is closed and the fifth passage is closed, it is possible to prevent the brake fluid in the hydraulic pressure generation device from being sucked into the electric pump through the fifth passage, and thus the hydraulic pressure in the wheel brake cylinder is reduced. Can be reliably reduced. It should be noted that this liquid pressure reduction state is stopped by stopping the electric pump.

Further, when the second valve is opened by the solenoid in the hydraulic pressure reduced state (state where the electric pump is operated), the second passage having the throttle is opened, so that the hydraulic pressure generator is passed through this second passage. The brake fluid is squeezed from the wheel brake cylinder to the wheel brake cylinder, and the hydraulic pressure in the wheel brake cylinder gradually rises. At this time, since the brake fluid flows through the second passage having the throttle, the differential pressure across the throttle becomes equal to or more than the set value, the first valve is held in the state where the first passage is closed, and the third valve is closed. Then, the third passage is closed.

Therefore, the hydraulic pressure of one wheel brake cylinder (for example, the first wheel brake cylinder), which is one system, is gradually increased, and the hydraulic pressure of the other wheel brake cylinder (for example, the second wheel brake cylinder) is increased. In the case of decreasing the hydraulic pressure, since the third passage corresponding to the one wheel brake cylinder in which the hydraulic pressure increases is closed, it is possible to suppress the intake of the brake fluid from the one wheel brake cylinder to the electric pump, The hydraulic pressure of the wheel brake cylinder, which decreases in pressure, is accurately reduced by the electric pump.

Further, 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.
Open the passage and set the first valve to the first position by the differential pressure across the throttle.
The passage is kept closed and the third valve is closed. When the electric pump is driven in this state, the normally-open type on-off valve connects the hydraulic pressure generator and the electric pump suction side to the fifth side.
In order to open the passage, the low-pressure brake fluid of the hydraulic pressure generator is sucked by the electric pump through the suction passage, and is pumped to the wheel brake cylinder through the fourth passage and the second passage having the throttle. At this time, since the connection between the hydraulic pressure generator and the connecting portion of the fourth passage with the first passage is cut off by the check valve, the brake fluid discharged from the electric pump is prevented from flowing out to the hydraulic pressure generator. Can be prevented. Further, since the third passage closes the third valve, it is possible to prevent the electric pump 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, when the solenoid is operated to close the second passage and the first passage while the electric pump is driven,
The third valve opens to open the third passage. 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 third passage. As a result, the hydraulic pressure of the wheel brakes is reduced.

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.

[0037]

DETAILED DESCRIPTION OF THE INVENTION A wheel brake hydraulic pressure control device according to an embodiment of the present 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, which corresponds to the invention of claim 1. . As shown in the figure, a front left wheel brake cylinder FL and a right rear wheel brake cylinder RR are integrated into one system, and a tandem master cylinder with a booster operated by a brake pedal 11 by one hydraulic circuit (a hydraulic pressure generating device). ) 10 is connected to one pressure chamber 10a.
Further, the front right wheel brake cylinder FR and the rear left wheel brake cylinder RL are integrated into one system, and the other pressure chamber 10b of the tandem master cylinder 10 is provided by the other hydraulic circuit.
It is connected to the.

Each hydraulic circuit has a first passage P1, a second passage P2, a third passage P3, and a fourth passage P4. The first passage P1 is formed in each pressure chamber 1 of the master cylinder 10.
It is a passage without a throttle that connects 0a (10b) and two wheel brake cylinders FL, RR (FR, RL) of one system. The second passage P2 is provided in parallel with the first passage P1 and has a diaphragm O1. One system of wheel brake cylinders FL, RR and wheel brake cylinders FR,
One electric pump B is provided for each RL system,
They are simultaneously driven by the drive motor M. The electric pump B recirculates the hydraulic pressure from each wheel brake cylinder side to the tandem master cylinder side during driving, thereby reducing the hydraulic pressure in each wheel brake cylinder. The third passage P3 connects the two wheel brake cylinders FL, RR (FR, RL) of one system 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. The valve device A includes a first valve V1, a second valve V2, a third valve V3, and a solenoid S. The first valve V1 is arranged in the first passage P1, and the normal-time master cylinder 10 is used as the first brake cylinder for each wheel brake cylinder.
A switching valve that communicates via a passage P1, disconnects the communication during operation, and connects the master cylinder 10 to the second passage P2. The second valve V2 is a normally-open type on-off valve arranged in the second passage P2. The third valve V3 has a third passage P
3 is a normally-open type on-off valve. Solenoid S
Is for opening and closing the second valve V2. The specific configuration of the valve device A will be described later.

In the first passage P1 between the connecting portion of the master cylinder 10 and the fourth passage P4 with the first passage P1, a switching valve V is provided.
4 are provided. This switching valve V4 connects the master cylinder 10 and the first valve V1 when not operating, and when the master cylinder 10 and the first valve V1 are operating (that is, when hydraulic pressure is applied to the wheel brake cylinder regardless of the brake operation), the master cylinder 10 and the first valve V1. V
1 is cut off and the master cylinder 10 is connected to the third passage P3 between the third valve V3 and the electric pump B.

A check valve C1 is connected in parallel to the first valve V1 corresponding to the front wheel brake cylinders FL, FR, and brake fluid from the front wheel brake cylinders FL, FR side to the pressure chambers 10a, 10b side of the master cylinder 10 is obtained. Only allow the flow of. In each third passage P3 (intake side of the electric pump) between each third valve V3 and the electric pump B, a check valve C2 and a throttle O2 are sequentially provided from the third valve side.
Are arranged. The check valve C2 blocks the reverse flow from the suction side of the electric pump to the side of each wheel brake cylinder. 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. In the fourth passage P4, a damper device D for reducing the discharge pulsation and a throttle E for reducing the pulsation of the output pressure of the master cylinder 10 are sequentially arranged from the pump discharge side.

The rear wheel brake cylinders RL and RR are respectively connected to the master cylinder 10 and the switching valve V via the return passage P5.
4 is connected to the first passage P1. This return passage P
Reference numeral 5 is for returning the brake fluid of the rear wheel brake cylinders RL, RR corresponding to the non-driving wheels to the master cylinder 10 when the anti-skid control is switched to the traction control. A check valve C3 that allows only the flow of the brake fluid from the rear wheel brake cylinders RL, RR side to the master cylinder 10 side is arranged in the return passage P5, and the rear wheel brake cylinder R during the anti-skid control is provided.
The master cylinder pressure is prevented from acting on the rear wheel brake cylinder when the L and RR pressures are reduced.

To the switching valve V4, check valves C4 for additional depression which allow only the flow of brake fluid from the master cylinder 10 side to the wheel brake cylinder side are connected in parallel. The fourth passage P4 is connected to the master cylinder 10 via a relief valve R, respectively. 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, a spherical valve portion 32a detachable from the valve seat 31, and a valve element 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 first valve V1 normally opens the first passage P1, and the spherical valve portion 32a of the valve body 32 is seated on the valve seat 31 to allow the first passage P1.
Is closed.

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 includes a valve seat 20a formed on the body 20 and a valve body 37 which is removable from the valve seat 20a.
And a spring 38 for urging the valve element 37 in a direction away from the valve seat 20a. The valve element 37 is the valve seat 20.
The third passage P3 formed between the valve element 37 and the valve seat 20a is opened when the valve element 37 is separated from a, and the third passage P3 is closed when the valve element 37 is seated on the valve seat 20a. The valve body 37 has a cylindrical shape, and is mounted on the outer periphery of the upper portion of FIG. The valve element 32 is liquid-tightly mounted on the inner periphery of the valve element 37 via the seal ring 42, the slide resin ring 43, and the clip 44 so as to be slidable upward with respect to the valve element 37. Here, the valve element 37 and the valve element 32 respectively apply the differential pressure across the throttle O1 to the spring 3
It receives against 8 and 33.

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 wheel brake hydraulic pressure 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 V 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. In this state (non-braking state), master cylinder 1
When 0 is operated, brake fluid flows from the master cylinder 10 to the wheel brake cylinders FL, R through the first passage P1 having no throttle which is opened by the first valve V1.
Immediately pumped to R, FR, RL.

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 inoperative and the solenoid of the valve device A is inactive. 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 second passage P2
Since the brake fluid does not flow to the throttle O1 in the second passage P2
A differential pressure is not generated before and after, the third valve V3 is maintained in the open state, and the third passage P3 is open.

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. The liquid pressure reduction state is stopped by stopping the electric pump B.

Further, when the second valve V2 is opened by the solenoid S in the hydraulic pressure decreasing state (state where the electric pump is operated), the second passage P2 having the throttle O1 is opened, so that the second passage P2 is opened. Through tandem master cylinder 10 to wheel brake cylinders FL, RR, FR, RL
The brake fluid is squeezed to the wheel brake pump, and the hydraulic pressure in the wheel brake cylinders FL, RR, FR, RL gradually rises. 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 valve body 32 of the first valve V1 is held at the position where it is seated on the valve seat 31. (That is, the first valve V1 is connected to the first passage P)
1 is kept closed) and the third valve V3
Valve body 36 closes the communication hole 35a (the third valve V3 closes and closes the third passage P3).

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.

Further, 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, 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. In this state, if the switching valve V4 is operated while the electric pump B is driven, the master cylinder 10 is connected to the electric pump suction side by the switching valve V4.
The low-pressure brake fluid of 0 is sucked in via the switching valve V4 and 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 master cylinder 10 and the first passage P of the fourth passage P4 are opened by the switching valve V4.
Since the connection between the connection part with 1 is disconnected, it is possible to prevent the brake fluid discharged from the electric pump B from flowing out to the master cylinder 10. Also, the third valve V
Since the third passage P3 is closed by 3, the electric pump B
Can be prevented 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 third valve V3 is opened and the third passage P3 is opened.
Opens. Then, the flow of the brake fluid discharged from the electric pump B to the wheel brake cylinder is cut off, 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.

As described above, 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.

(Second Embodiment) In the second embodiment,
This corresponds to the invention of claim 2 and is the one in which the switching valve V4 of the first embodiment is modified as follows. That is, as shown in FIG. 3, when the brake fluid pressure is applied to the wheel brake cylinder irrespective of the brake operation in the first passage P1 between the connection portion of the master cylinder 10 and the fourth passage P4 with the first passage P1. A normally open first opening / closing solenoid valve (first opening / closing valve) V5 that closes is provided. Also, master cylinder 1
0 indicates the first opening / closing solenoid valve V by the suction passage (fifth passage) P6.
A normally closed type that is connected to the third passage P3 between the third valve V3 and the electric pump B without passing through 5, and is opened when the brake fluid pressure is applied to the wheel brake cylinders regardless of the brake operation in the suction passage P6. Second open / close solenoid valve (second
An on-off valve) V6 is provided. The second opening / closing solenoid valve V
6 may be a normally open valve.

(Third Embodiment) In the third embodiment,
It corresponds to the invention of claim 3 and is a modification of the second embodiment as follows. That is, as shown in FIG.
Instead of the normally open first opening / closing solenoid valve V5 of the second embodiment, the first valve V from the master cylinder 10 side to the same portion.
Check valve C that allows only the inflow of brake fluid to the 1 side
5 are provided. Further, instead of the normally closed second opening / closing solenoid valve V6 of the second embodiment, the electric pump B is installed in the same portion.
A normally-open type on-off solenoid valve V7 that is closed when the wheel brake cylinder is depressurized by the above is provided.

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

[0063]

According to the first to third aspects of the present invention, when the hydraulic pressure of one wheel brake cylinder which is one system gradually rises, the brake fluid is sucked into the electric pump from the other wheel brake cylinders. When the hydraulic pressure in the same cylinder decreases, the third valve, which corresponds to the wheel brake cylinder whose hydraulic pressure increases, is closed by the differential pressure across the throttle in the second passage to close the third passage. Intake of brake fluid from the ascending wheel brake cylinder to the electric pump can be suppressed, and the hydraulic pressure of the wheel brake cylinder that decreases can be accurately reduced by the electric pump.

As described above, since the third valve is closed by the differential pressure across the throttle of the second passage, it is not necessary to use the third valve as a solenoid valve as in the conventional case, and a large valve for driving the solenoid valve is used. A large solenoid is also unnecessary. As a result, not only is it advantageous in terms of cost and mounting space, but it is also advantageous in terms of controllability of the device.

Further, the hydraulic pressure can be applied to the wheel brake cylinders when the brakes are not operated, and the hydraulic pressures can be adjusted. As a result, traction control, automatic brake control and the like can be realized.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a wheel brake pressure 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 wheel brake pressure control device according to a second embodiment of the present invention.

FIG. 4 is an overall configuration diagram of a wheel brake pressure control device according to a third embodiment of the present invention.

[Explanation of symbols]

 10 Tandem master cylinder (hydraulic pressure generator) 11 Brake pedal FL, RR, FR, RL Wheel brake cylinder B Electric pump P1 1st passage P2 2nd passage P3 3rd passage P4 4th passage P6 Return passage (5th passage) A valve device V1 first valve V2 second valve V3 third valve S solenoid O1 throttle V4 switching valve V5 first opening / closing solenoid valve (first opening / closing valve) V6 second opening / closing solenoid valve (second opening / closing valve) V7 opening / closing solenoid valve (Open / close valve) C5 check valve

Claims (3)

[Claims] 1. A hydraulic pressure generator for generating a hydraulic pressure corresponding to a brake operating force, a first wheel brake cylinder and a second wheel brake for receiving a hydraulic pressure output from the hydraulic pressure generator and braking a corresponding wheel. A cylinder, a first passage without a throttle that connects the hydraulic pressure generating device to the two-wheel brake cylinder, a second passage with a throttle provided in parallel with the first passage, and the two-wheel brake An electric pump for returning hydraulic pressure from the cylinder side to the hydraulic pressure generator side, a third passage connecting the suction side of the electric pump to each of the wheel brake cylinders, and a discharge side of the electric pump for the liquid A fourth passage connected to the first passage on the pressure generating device side, a first valve that opens and closes the first passage and normally opens the first passage, and the first valve in cooperation with the first valve. Two
A second passage which is opened and closed to normally close the second passage.
A wheel brake, which has a valve, a third valve that is disposed in the third passage and normally opens the third passage, and a solenoid that operates the second valve, and cooperates with the electric pump. A valve device for adjusting a hydraulic pressure of a cylinder; and a valve device disposed in the first passage between a connecting portion of the hydraulic pressure generating device and the first passage of the fourth passage, the non-operating hydraulic pressure generating device, A switch for connecting the first valve, disconnecting the hydraulic pressure generator and the first valve during operation, and connecting the hydraulic pressure generator to the third passage between the third valve and the electric pump. A valve, and when the second valve is normally closed by the solenoid, the first valve is closed via the second valve to close the first passage. The state where the passage and the second passage are closed In when the second valve by the solenoid is opening operation, by the differential pressure of the diaphragm is greater than or equal to a set value, the first
A wheel brake hydraulic pressure control device configured such that a valve is held in a state in which the first passage is closed and the third valve is closed to close the third passage. 2. A hydraulic pressure generating device for generating a hydraulic pressure corresponding to a brake operating force, a first wheel brake cylinder and a second wheel brake for receiving a hydraulic pressure output from the hydraulic pressure generating device and braking a corresponding wheel. A cylinder, a first passage without a throttle that connects the hydraulic pressure generating device to the two-wheel brake cylinder, a second passage with a throttle provided in parallel with the first passage, and the two-wheel brake An electric pump for returning hydraulic pressure from the cylinder side to the hydraulic pressure generator side, a third passage connecting the suction side of the electric pump to each of the wheel brake cylinders, and a discharge side of the electric pump for the liquid A fourth passage connected to the main passage on the pressure generating device side, a first valve that opens and closes the first passage and normally opens the first passage, and the second valve in cooperation with the first valve.
A second passage which is opened and closed to normally close the second passage.
A wheel brake, which has a valve, a third valve that is disposed in the third passage and normally opens the third passage, and a solenoid that operates the second valve, and cooperates with the electric pump. The wheel brake is arranged in the first passage between the valve device for adjusting the hydraulic pressure of the cylinder and the connecting portion between the hydraulic pressure generator and the first passage of the fourth passage, and is independent of the brake operation. A normally open first opening / closing valve that closes when a brake fluid pressure is applied to the cylinder; and the first opening / closing valve between the fluid pressure generator and the first opening / closing solenoid valve.
A passage is formed between the third valve and the electric pump.
A fifth passage for connecting to the passage; and a second opening / closing valve which is disposed in the fifth passage and which is opened at least when brake hydraulic pressure is applied to the wheel brake cylinder irrespective of a brake operation, When the second valve is normally closed by the solenoid, the first valve is closed through the second valve to close the first passage, and the first passage and the second passage are closed. When the second valve is opened by the solenoid while the passage is closed, the differential pressure across the throttle becomes equal to or greater than a set value, so that the first
A wheel brake hydraulic pressure control device configured such that a valve is held in a state in which the first passage is closed and the third valve is closed to close the third passage. 3. A hydraulic pressure generator for generating a hydraulic pressure corresponding to a brake operating force, a first wheel brake cylinder and a second wheel brake for receiving a hydraulic pressure output from the hydraulic pressure generator and braking a corresponding wheel. A cylinder, a first passage without a throttle that connects the hydraulic pressure generating device to the two-wheel brake cylinder, a second passage with a throttle provided in parallel with the first passage, and the two-wheel brake An electric pump for returning hydraulic pressure from the cylinder side to the hydraulic pressure generator side, a third passage connecting the suction side of the electric pump to each of the wheel brake cylinders, and a discharge side of the electric pump for the liquid A fourth passage connected to the main passage on the pressure generating device side, a first valve that opens and closes the first passage and normally opens the first passage, and the second valve in cooperation with the first valve.
A second passage which is opened and closed to normally close the second passage.
A wheel brake, which has a valve, a third valve that is disposed in the third passage and normally opens the third passage, and a solenoid that operates the second valve, and cooperates with the electric pump. A valve device for adjusting the hydraulic pressure of a cylinder, and the first passage between the hydraulic pressure generating device and the connecting portion of the fourth passage with the first passage, the hydraulic pressure generating device being connected to each of the wheels. A check valve that allows only the inflow of brake fluid to the brake cylinder side, and the first passage between the hydraulic pressure generator and the check valve is connected to the third passage between the third valve and the electric pump. And a normally open-type on-off valve which is disposed in the fifth passage and closes when at least one of the wheel brake cylinders is decompressed by an electric pump. When the second valve is closed, the first valve is closed via the second valve to close the first passage, and the first passage and the second passage are closed. When the second valve is opened by the solenoid, the differential pressure across the throttle becomes equal to or more than a set value, so that the first
A wheel brake hydraulic pressure control device configured such that a valve is held in a state in which the first passage is closed and the third valve is closed to close the third passage.