JPS58206455A - Brake oil pressure control valve for vehicle - Google Patents

Abstract

PURPOSE:To permit proportional control and antilock control without generating kickback to a master cylinder by installing a piston for releasing the power of the set spring of a hydraulic control valve by means of a control pressure and allowing said piston to operate when wheels are locked. CONSTITUTION:The hydraulic pressure to a rear wheel brake Br is controlled by a proportional reducing valve constituted of a decompression piston 21 and a set spring 23, and decreased in comparison with a front wheel brake Bf. A control circuit 29 switches a solenoid valve 24 on the basis of a signal from a wheel sensor 30 and introduces the oil pressure from a pump 28 into a controlled oil- pressure chamber 36. Therefore, a control piston 35 allows the decompression piston 21 to retreat against the power of the set spring 23. Then, a valve 15 is closed, and an output hydraulic pressure chamber 11 is spread to weaken the rear-wheel brake power. Since a pressure receiving piston 6 is not applied with the power of the control piston 35, kickback to a master cylinder is not generated.

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a hydraulic pressure lower than that of the front brakes is supplied as the rear brake hydraulic pressure.
The present invention relates to a vehicle brake hydraulic control valve device.

As this type of brake hydraulic control valve device, a valve surface is interposed in the oil passage connecting between the output port of the mask cylinder and the rear wheel brake, and the output hydraulic pressure of the output port is transferred to the rear wheel brake V. - a pressure reducing valve capable of proportionally reducing and transmitting pressure to the key;
It is known that the pressure reducing valve is provided with a pressure regulating spring that biases the pressure reducing valve in the valve opening direction and determines the pressure at which the pressure starts to be reduced. According to this brake hydraulic control valve device, when a braking input of a certain value or more is applied, the front wheel brake is applied strongly to the front wheel on the side where the downward load of the vehicle body increases, and the front wheel brake is applied strongly to the front wheel on the side where the downward load is decreased. The advantage is that the rear wheel brakes can be operated weakly to achieve more efficient braking.

However, even when such a brake oil pressure control valve device is used, when the braking input is excessive or when the road surface conditions are poor, the rear wheels may become locked and the braking efficiency may decrease.

Therefore, the present invention is capable of exhibiting an anti-lock function without impairing the above-mentioned advantages, and does not cause the so-called kick-pack phenomenon in which the control hydraulic pressure is transmitted from the pressure reducing valve side to the mask cylinder side during anti-lock control. It is an object of the present invention to provide a simple and effective brake hydraulic control valve device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. M is a known tandem mask cylinder operated by a brake pedal BpK, and has independent first and second output ports pj and p2.

Bfl, Br2 are left and right front wheel brakes, Brx.

Br2 indicates the left and right rear wheel brakes, respectively, and the first
The hydraulic actuating parts of the left front wheel brake Bf1 and the right rear wheel brake Br2 are connected to the first oil passage I, 1 extending from the output port P1, and the second oil passage extending from the second output boat P, Right front wheel brake B, It and left rear wheel brake I
Jr., each hydraulic operating section is connected. Therefore, the first
The second oil passage LIeLt is a so-called X-shaped pipe. Then, the brake hydraulic pressure control valve device V of the present invention is interposed in the first and second oil passages Ll pI, 2 leading to the left and right rear wheel brakes Br, Br.

The brake hydraulic control valve device V has a valve surface 1 that is fixed in place on the vehicle body. The right side of this valve face 1 is connected to the upstream side (mask cylinder side) of the first oil passage [ ] 2
1 and the same downstream side (brake side) are connected to the first outlet 31
A second outlet 32 is provided on the left side of the second oil passages I and 2, and the second outlet 22 is connected to the upstream side of the second oil passages I and 2, and the second outlet 32 is connected to the downstream side of the second oil passages I and 2. These first population 21 and first exit 3
1. First and second pressure reducing valves that control communication and isolation between the second port 22 and the second outlet 32; 4. ．． 4. are arranged in parallel within the valve surface 1.

Both pressure reducing valves 4. ,4. Since they have the same configuration, only the configuration of the first pressure reducing valve 41 will be explained.

The valve surface 1 is provided with stepped cylinder holes consisting of a large diameter cylinder hole 5a at the front, a small diameter cylinder hole 5b at the middle, and a large diameter cylinder hole 5C at the rear.
A bearing 8 is fitted into the cylinder hole 5b at the intermediate portion, and a pressure receiving piston 6 is slidably engaged with the cylinder hole 5b at the intermediate portion through a sealing member 7. It will be installed protrudingly. A decompression piston 21 is slidably fitted into the rear cylinder hole 5c via a seal member 22. The decompression piston 21 is normally held at its forward limit, where it abuts against the front end wall of the cylinder hole 5c, by the elastic force of a set spring 23, which will be described later.

The pressure receiving piston 6 includes a piston rod 6a that projects from its front end surface, and a valve seat member 6h that projects from its rear end surface.
The intermediate portion of the piston rod 6α is connected to the bearing 8.
It is slidably supported via a seal member 9. In the cylinder hole 5h, the pressure receiving piston 6 and the bearing 8 have the first population 2. Front input hydraulic chamber 1 communicating with
0 and also defines a rear output hydraulic chamber 11 communicating with the first output 113 between the control piston 22 and the first output 113 .

Further, a valve chamber 12 is formed in the pressure receiving piston 6,
This valve chamber 12 communicates with the input hydraulic pressure chamber 10 via the through hole 13 of the piston rod 6a, and also communicates with the input hydraulic pressure chamber 10 through the through hole 13 of the valve seat member 6h.
It also communicates with the output hydraulic chamber 11 via 4. The valve chamber 12 accommodates a spherical valve 15 that is seated on the valve seat member 6b and can close the valve hole 14, and a valve closing spring 16 that biases the valve toward the closing side.

The valve 15 is integrally equipped with a valve opening rod 17 that passes through the valve hole 14 loosely, and when the pressure receiving piston 6 is located at the retraction limit, the valve opening rod 17 is pushed by the pressure reducing piston 21 and the valve 15 is opened.
It looks like this.

At the front of the valve surface 1 is a front spring chamber 1 that accommodates a pressure regulating spring 18.
9 is defined by cover 1h. In the chamber 19,
Both ends of a lever 200 are swingably connected to the front ends of the two piston rods 5a and 6a of the first and second pressure reducing valves 41+42. It is applied to push the piston 6.6 to the retraction limit.

Further, at the rear of the valve surface 1, a rear spring chamber 32 for accommodating the set spring 23 is defined by a force-IC.

In the chamber 32, first and second pressure reducing valves 41. A bridge plate 33 is separably or integrally connected to the rear end of the decompression pistons 21 and 21 of 42, and the elastic force of a set spring 23 is applied to the center of the bridge plate 33.
1 should be applied so as to press and hold it at the forward limit. In this case, the elastic force of the set spring 23 is
It is set to be smaller than the retraction force of both pressure reducing pistons 21 and 21 due to the maximum oil pressure of No. 11.

Further, in the valve surface 1, a cylinder hole 34 is provided in the middle part between the left and right cylinder holes 5b and 5A, parallel to these cylinder holes and having a closed front end. It is rubbed together. This control piston 3
5 defines a control hydraulic chamber 36 between the cylinder hole 34 and the front end wall thereof.

"This control hydraulic chamber 36 is connected to the oil tank 25 and the pressure accumulator 26 via the solenoid valve 24. When the solenoid valve 24 is demagnetized, it communicates with the oil tank 25, and when it is energized, it communicates with the pressure accumulator 26.
It is designed to communicate with

The pressure accumulator 26 stores oil discharged from a hydraulic pump 28 driven by an electric motor 27.

A control circuit 29 is provided to control the electromagnetic valve 24.b This circuit 29 includes first and second wheel speed sensors 30, . 30. When it is determined that the rear wheels are about to be locked, an excitation signal is sent to the solenoid valve 24. Also, this circuit 2
9 receives a signal 7 from a pressure sensor 31 that detects the oil pressure in a hydraulic circuit connected to the pressure accumulator 26, and issues a stop signal to the electric motor 21 when it is determined that a predetermined oil pressure has been stored in the pressure accumulator 26.

Next, to explain the operation of this embodiment, if the mask cylinder M is actuated by depressing the brake pedal/Jp while the vehicle is running, hydraulic pressure is output from the first and second output boats p, p2, respectively. , the output oil pressure of the first output boat P1 is sent to the left front wheel brake Bf1 via the first oil path L1, and to the first pressure reducing valve 410 and the input oil pressure chamber 10 at the upstream part of the first oil path.
, valve chamber 12, valve hole 14, output hydraulic chamber 11, and first oil passage L
1 to the right rear wheel brake Br, respectively, to operate them. On the other hand, the output oil pressure of the second output port P2 is transmitted to the right front wheel brake 11f2 via the second oil 8 Lt.
Also, the second oil passage I1. The left rear wheel brake 1Jr passes through the upstream part of the second pressure reducing valve 4, the input hydraulic chamber 10, the valve chamber 12, the valve hole 14, the output hydraulic chamber 11, and the downstream part of the second oil passage Z7□.
1 to operate these.

The working oil pressure of the front wheel brakes Bf1, Bf always rises together with the output oil pressure of the first and second output ports Ps-Pt, but the working oil pressure of the rear wheel brakes IJrItIJr2 increases at the same time as the output oil pressure of the first and second output ports Ps-Pt. ',.

After the output oil pressure of P exceeds a predetermined value, the first and second pressure reducing valves 41.4□ are controlled as follows.

First, due to the increase in the output oil pressure of the first output port P1, the first
When the oil pressure in the pressure reducing valve 410 and the output oil pressure chamber in, ii reaches a predetermined value, the forward pressing force of the oil pressure on the pressure receiving piston 6 (the force obtained by multiplying the cross-sectional area of the piston rod 6a by the oil pressure) is the pressure regulator. The valve opening force of the spring 18 against the pressure receiving piston 6 (
The pressure regulating spring 18 applies a valve opening force to the two left and right pressure receiving pistons 6°6 via the lever 20.
One-half of the set load of 8 becomes the valve opening force for one pressure receiving piston 6. ), the pressure-receiving piston 6 is moved forward without tilting the lever 20 slightly, the valve seat member 675 is engaged with the valve 15, and the valve hole 14 is closed. cut off communication between Thereafter, the output oil pressure of the first output port P8 further increases, and the rearward pressing force of the oil pressure of the input oil pressure chamber 10 on the pressure receiving piston 6 (the cross-sectional area of the large diameter portion of the pressure receiving piston 6 and the cross-sectional area of the piston rod 6a) multiplied by the hydraulic pressure of the input hydraulic chamber 10) is the forward pressing force of the hydraulic pressure of the output hydraulic chamber 11 against the pressure receiving piston 6 (the difference between the hydraulic pressure of the output hydraulic chamber 11 and the cross-sectional area of the large diameter portion of the pressure receiving piston 6). The pressure-receiving piston 6 is pushed back to separate the valve 15 from the valve seat member 6h, and the pressure chambers 10 and 11 are communicated again, so that the pressure in the output hydraulic chamber 11 is increased. As the pressure rises, the forward pressing force of the hydraulic pressure of the output hydraulic pressure chamber 11 on the pressure receiving piston 6 increases immediately, and the pressure receiving piston 6 is moved forward again to cut off communication between the meat pond pressure chambers 10 and 11.

Thereafter, the same action is repeated as the output oil pressure of the first output port P1 increases, and as a result, the output oil pressure of the first output port P0 is proportionally reduced in pressure and transmitted to the right rear wheel brake 11r2.

Further, if the output oil pressure of the second output port P2 rises above a predetermined value, the second pressure reducing valve 4. It is clear that the second output pressure reducing valve 4 operates in the same manner as the first pressure reducing valve 4, so that the output hydraulic pressure of the second output coupler Pt is proportionally reduced in pressure and transmitted to the left rear wheel brake Br1.

In the above, each pressure reducing valve 4□, 4. The depressurization start pressure is determined by the cross-sectional area of each piston rod 6α and the set load of the pressure regulating spring 1B, and the depressurization ratio is determined by the difference between the cross-sectional area of the large diameter portion of the pressure-receiving piston 6 and the cross-sectional area of the piston rod 6α, It is determined by the ratio to the cross-sectional area of the piston rod a.

During this braking, if the rear wheels are about to lock up, the control circuit 2
9 issues an excitation signal to the solenoid valve 24, so the solenoid valve 24 is excited and switched to a position where the pressure accumulator 26 and the control hydraulic chamber 23 communicate with each other, and the hydraulic pressure of the pressure accumulator 26 is supplied to the control hydraulic chamber 23. . Then, in response to the oil pressure, the control piston 3
5 operates rearward to compress the set spring 23 via the bridge plate 33 and release the pressing force of the set spring 23 against both wave pressure pistons 21 and 21. For this reason, each pressure reducing piston 21 moves backward by the hydraulic pressure of the corresponding output hydraulic chamber 11, but the pressure receiving piston 6 stops at the position where it contacts the stopper 1a, that is, at the backward limit, so that the valve opening rod 17 eventually moves back to the pressure reducing position. The pressure of the piston 21 is released, allowing the valve 15 to close, and after the valve is closed, the output hydraulic pressure chamber 11 is depressurized in accordance with the retreat of the decompression piston 21. Thus, the rear wheel brake Brl.

The braking force of Br2 is weakened and the locked state is avoided.

During this time, the pressure receiving piston 6 is held in the contact position with the stopper 1α by the hydraulic pressure of the input hydraulic pressure chamber 10, so the operating force of the control piston 350 is not transmitted to the pressure receiving piston 6, that is, no kickback phenomenon occurs.

If the locked state is avoided, the control circuit 29 stops the excitation signal, so the solenoid valve 24 is demagnetized and returns to its original position.
The hydraulic pressure in the control hydraulic chamber 36 is released to the oil tank 25. Therefore, the control piston 35 stops operating, so that both pressure reducing pistons 21.21 are held again at their original forward limit by the elastic force of the set spring 23, and each pressure reducing valve 41.4. to return to normal operating condition, rear wheel brakes Br,, Br
Restores the braking power of 2.

In the above embodiment, both the left and right pressure reducing pistons 21, 21 are connected via the bridge plate 33, and the set spring 23 and the control piston 35 are common to both the pressure reducing pistons 21, 21, respectively. The setting spring 23 and the control piston 35 may be provided for each pressure reducing piston 21 without using the plate 33 (in this case, the pressure reducing piston and the control piston can be integrally formed).

As described above, according to the present invention, the valve surface that accommodates the pressure reducing valve and the pressure regulating spring is provided with a valve surface that is normally held at the forward limit where the pressure reducing valve can be opened by the elastic force of the set spring. a pressure reducing piston that closes the pressure reducing valve and retreats to reduce the pressure on the output side of the pressure reducing valve when the elastic force is released;
A control hydraulic chamber to which hydraulic pressure is supplied from a hydraulic source when the rear wheel is about to enter a lock state, and a control piston that is actuated by the hydraulic pressure of the control hydraulic chamber to release the elastic force of the set spring from the depressurizing piston. As a result, when the rear wheels are about to lock up, the control piston is operated to move the pressure reducing piston backwards to reduce the rear wheel brake hydraulic pressure, thereby avoiding the locking condition. During anti-lock control, the pressure reducing valve is held at the retraction limit by the output hydraulic pressure of the mask cylinder and is not subjected to the actuation force of the control piston, so no kickback phenomenon occurs.

In addition, in the unlikely event that a failure occurs in the hydraulic system of the control piston system,
If the control piston becomes inoperable, the pressure reducing piston can continue to maintain its normal forward position due to the elastic force of the set spring, so the pressure reducing valve will perform its normal proportional pressure reducing function and will not interfere with braking. (Failsafe is ensured.)

Furthermore, the anti-lock function can be added to a conventional brake hydraulic control valve device by simply adding a pressure reducing piston, a set spring, and a control piston, so the configuration is simple, and by adding these, this type of control valve device can be provided with an anti-lock function. The original advantages of the valve device are not diminished in any way.

[Brief explanation of the drawing]

The drawing is a brake hydraulic circuit diagram for an automobile equipped with a control valve device based on an embodiment of the present invention. Bf+ -Bf 2''' Left and right front wheel brakes, Br2... Left and right rear wheel brakes, M... Mask cylinder, r... Brake hydraulic control valve device, 1... Valve surface, 1α゛°・Stopper, 6...Pressure receiving piston, 10・
...Input hydraulic chamber, 11...Output hydraulic chamber, 15...Valve, 18...Pressure regulating spring, 21...Pressure reducing piston,
23...Set spring, 24...Solenoid valve, 26...
Pressure accumulator as a hydraulic source, 28...hydraulic pump, 29
...Control circuit, 35...Control piston, 36...
Control hydraulic chamber patent applicant Nissin Kogyo Co., Ltd.;! '-'+-', p

Claims (1)

[Claims] A valve surface is interposed in the oil passage connecting between the output port of the mask cylinder and the rear wheel brake, and the output hydraulic pressure of the output port is proportionally reduced in pressure and transmitted to the rear wheel brake to the valve surface. A brake hydraulic control valve device for a vehicle is provided with a pressure regulating spring that biases the pressure reducing valve in the opening direction and determines the pressure at which the pressure starts reducing. The elastic force of the spring holds the pressure reducing valve at the forward limit where it can be opened, and when the elastic force of the set spring is released, the pressure reducing valve is closed and the output 11111 of the pressure reducing valve is released.
a pressure-reducing piston that moves backward to reduce the pressure; a control oil pressure chamber that receives oil pressure from the oil source when the rear wheels are about to enter the lock state; A brake hydraulic control valve device for a vehicle, comprising: a control piston that releases power from the pressure reducing piston.