JPH0781534A - Vehicle brake pressure controller - Google Patents

Abstract

(57) [Summary] [Structure] Right front wheel 1R and left rear wheel 2 on one diagonal line
A brake pipe 4 ₁ connecting the brake 3,3 L, left front wheel 1L and the right rear wheel 2R of the brake 3 that is on the other diagonal line,
A brake pipe 4 ₂ connecting 3 is provided, and a load sensing valve 7 is provided in each brake pipe. A load detection means 11 for detecting the load of each wheel is provided, and a load signal corresponding to the load difference between the front and rear wheels on the corresponding diagonal line is input to each load sensing valve, and the front and rear wheels are braked according to this load difference. Perform pressure distribution. [Effect] Even during turning, it is possible to appropriately distribute the brake pressure according to the load movement accompanying the turning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake pressure control device capable of appropriately controlling brake pressure distribution between front and rear wheels.

[0002]

2. Description of the Related Art Conventionally, as a brake pressure control device for a vehicle, as shown in Japanese Patent Publication No. 58-32058, a road for controlling distribution of brake pressure supplied to brakes of front and rear wheels according to a load of rear wheels. It is known that a sensing valve is provided to prevent the rear wheel from locking. In this system, the brake pressure is supplied to the brakes of the left and right rear wheels via a common load sensing valve.

[0003]

In the above, since the load signal input to the load sensing valve is only the load signal of the rear wheels, it is necessary to appropriately distribute the brake pressure according to the front wheel load and the rear wheel load. In addition, since the common load sensing valve controls the brake pressures of the left and right rear wheels, it is impossible to appropriately distribute the brake pressure corresponding to the load movement during turning. In view of the above points, the present invention provides an apparatus capable of performing appropriate brake pressure distribution according to the loads of front and rear wheels, and also capable of performing appropriate brake pressure distribution during turning. Has an aim.

[0004]

[Means for Solving the Problems] In order to achieve the above object,
The present invention is provided with a pair of brake pipes that respectively connect the brakes of front and rear wheels on a diagonal line, is provided with each load detection means for detecting the load of each wheel, and each brake pipe is located on the corresponding diagonal front and rear lines. It is characterized in that a load sensing valve for controlling the distribution of the brake pressure supplied to the brakes of the front and rear wheels is provided in accordance with the detected amount of the load of the wheels.
In this case, the load detection means is configured to generate a hydraulic pressure corresponding to the load of each wheel, and the differential pressure of the hydraulic pressure generated from the load detection means of the front and rear wheels on a diagonal line is applied to the load sensing valve. It is desirable to input as a load signal.

[0005]

[Function] Since the brake pressure distribution of the front and rear wheels is controlled according to the load of the front and rear wheels, for example, when the load difference between the front and rear wheels becomes large, the brake pressure reduction ratio of the rear wheels is increased to ensure the rear wheel lock. Can be prevented. In addition, since the brake pressure distribution of the front and rear wheels on one diagonal line and the brake pressure distribution of the front and rear wheels on the other diagonal line are controlled by separate load sensing valves, the brake pressure of the rear wheels on the inner wheel side is reduced when turning. The ratio can be increased to prevent the lock, and the braking performance can be improved by decreasing the brake pressure reduction ratio of the rear wheel on the outer wheel side.

[0006]

EXAMPLE FIG. 1 shows a brake system of an automobile.
A brake pipe 4 ₁ connecting the brake 3,3 of the right front wheel 1R and the left rear wheel 2L in the one diagonal line connecting the brake 3,3 of the left front wheel 1L and the right rear wheel 2R in the other diagonal brake pipe 4 ₂ is provided, and a pair of output pipes 6 ₁ and 6 ₂ of the master cylinder 6 which is interlocked with the brake pedal 5 is connected to both brake pipes 4 ₁ and 4 ₂ .

A load sensing valve 7 is provided in each of the brake pipes 4 ₁ and 4 ₂ , and the rear wheel brake pressure is controlled to be reduced with a characteristic according to a load signal input to each valve 7.

As shown in FIG. 3, the load sensing valve 7 has an input port 8 for inputting the output pressure of the master cylinder.
A pair of first and second proportioning valves 9 ₁ and 9 ₂ are provided in parallel in a valve casing 8 having a and an output port 8b for connecting a brake for the rear wheels.

Each proportioning valve 9 ₁ , 9 ₂ is
A plunger 90 is provided to be inserted into each stepped hole formed in the valve casing 8. An annular valve seat 91 is mounted on the bottom surface of the large diameter portion of the stepped hole, and the plunger 90 is attached.
Is formed at the left end in the figure, the valve element 92 fitted in the small diameter portion of the stepped hole is formed. According to the right movement of the plunger 90, the valve element 92 contacts the valve seat 91 as shown in FIG. As a result, the communication between the inflow liquid chamber 93 composed of the large diameter portion of the stepped hole and the outlet 94 connected to the bottom of the small diameter portion of the stepped hole is cut off, and according to the left movement of the plunger 90, as shown in FIG. As shown in b), the valve 92
Is separated from the valve seat 91 so that the inflow liquid chamber 93 and the outlet 94 are communicated with each other through the groove 92a on the outer peripheral surface of the valve element 92 and the shaft hole 92b, and further to the right end side of the stepped hole. A seal member 95 for sealing the inflow liquid chamber 93 and a guide sleeve 96 are mounted, the right end portion of the plunger 90 is fitted into the seal member 95 and the guide sleeve 96, and the right end portion of the plunger 90 is spring-loaded via a seat 97a. 97 is abutted, and the spring 97 urges the plunger 90 toward the left open side. The left side of the plunger 90 is restricted by a stopper 98 attached to the bottom of the small diameter portion of the stepped hole, and the plunger 90 is formed with a piston portion 99 loosely inserted in the large diameter portion of the stepped hole. , Plunger 9
The piston portion 99 is brought into contact with the projection 91a for securing a gap provided on the right side surface of the valve seat 91 at a predetermined leftward movement position of 0.

The individual proportioning valves 9 ₁ , 9 ₂
Is operated so as to control the output pressure on the outlet 94 side with respect to the input pressure on the inflow liquid chamber 93 side at the break point, that is, the plunger 90 is initially moved to the left by the urging force of the spring 97, and the output pressure is It rises at the same pressure as the input pressure, but at this time the plunger 90
Is pressed toward the right side by the output pressure acting on the left end surface of the valve element 92, the output pressure rises to a predetermined value, and when the pressing force toward the closing side exceeds the urging force of the spring 97, the plunger 90 moves. The valve seat 91 is closed by moving to the right, and even if the plunger 90 is once moved to the left due to the increase in the input pressure, the plunger 90 is again moved to the right due to the increase in the output pressure and the valve seat 91 is closed, and this operation is repeated. The output pressure is reduced by a predetermined ratio with respect to the input pressure and rises, and a break point appears when the output pressure reaches the predetermined value.

Here, the first proportioning valve 9
The biasing force of the spring 97 of ₁ is set stronger than the biasing force of the spring 97 of the second proportioning valve 9 ₂ , and thus the break point value of the first proportioning valve 9 ₁ is the second.
It is larger than that of the proportioning valve 9 _2. Also, the outlet 9 of the first proportioning valve 9 ₁
4 is communicated with the inflow liquid chamber 93 of the second proportioning valve 9 ₂ via the communication passage 8c in the valve casing 8, and the inflow liquid chamber 93 of the first proportioning valve 9 ₁ is connected to the input port 8a and the second The outlets 94 of the proportioning valves 9 ₂ were made to communicate with the output ports 8b, respectively, and both proportioning valves 9 ₁ , 9 ₂ were interposed in series between the input ports 8a and the output ports 8b.

[0012] Te Thus, rear wheel brake pressure outputted from the output port 8b, the output pressure of up increases the folding point value of the second proportioning valve 9 ₂ master cylinder is input to the input port 8a (front wheel brake becomes isobaric and correspond to pressure), then the pressure reduction control by the operation of the second proportioning valve 9 _2, even more significant by the operation of the valve 9 ₁ in the first proportioning valve 9 ₁ folding points value or more regions Decompression control is performed by the ratio, and the braking force line is shown in FIG.
As shown in, a first break point corresponding to the break point value of the second proportioning valve 9 _{2 and} a second break point corresponding to the break point value of the first proportioning valve 9 ₁ appear.

By the way, the ideal braking force distribution curve changes according to the load difference between the front wheel load and the rear wheel load. When the load difference is large, line a in FIG. In order to approximate the actual braking force line to the respective ideal braking force distribution curves, it becomes necessary to change each break point according to the load difference between the front and rear wheels.

The load sensing valve 7 is an urging force for setting the breaking points of both the proportioning valves 9 ₁ and 9 ₂ .
That is, a movable spring bearing 10 for receiving the springs 97, 97 is provided so that the biasing force of the springs 97, 97 of the valves 9 ₁ , 9 ₂ can be varied, and the spring bearing 10 is displaced. Thus, the folding point can be changed.

In the present embodiment, as shown in FIG. 1, the load detecting means 11 for detecting the load of each wheel is provided, and the brakes 3 for the right front wheel 1R and the left rear wheel 2L are located on one diagonal line.
A load signal corresponding to the load difference between the right front wheel 1R and the left rear wheel 2L is input to the load sensing valve 7 provided in the brake pipe 4 ₁ connecting 3 and the left front wheel 1L and the right rear wheel on the other diagonal line. the left front wheel 1L on the load sensing valve 7 which is interposed in the brake pipe 4 ₂ connecting brake 3,3 2R
And a load signal according to the load difference between the right rear wheel 2R and the spring bearing 10 of each load sensing valve 7 is displaced according to each load signal, and the load difference between the front and rear wheels on the diagonal line is large. Reduces the biasing force of the springs 97, 97,
The actual braking force line is approximated to the ideal braking force distribution curve a at the time of a large load difference by reducing the values of both the first and second folding points, and the spring is set when the load difference is small as shown by line A in FIG. 9
The urging forces of Nos. 7 and 97 are increased and the values at both break points are increased to approximate the actual braking force line to the ideal braking force distribution curve b at the time of a small load difference as shown by line B in FIG.

In this case, the load detecting means 11 may be composed of a load cell or the like for generating an electric signal according to the load, and the spring bearing 10 may be displaced by a solenoid, but the reliability of the control system is improved. In order to improve, it is desirable that the spring bearing 10 can be directly displaced according to the load difference without using an electric signal.

Therefore, in this embodiment, as shown in FIG.
A cylinder for inputting the hydraulic pressure generated from the load detecting means 11, 11 for the front and rear wheels on a diagonal line to each other by providing load detecting means 11 for generating hydraulic pressure according to the load on the top of the suspension 12 of each wheel. 13 is provided and the cylinder 13
Piston rod 13a is connected to the spring receiver 10 of the load sensing valve 7, and front and rear wheel load detecting means 11, 1
The spring bearing 10 is displaced according to the differential pressure of the hydraulic pressure generated from 1. As shown in FIG. 2B, the load detecting means 11 is composed of a piston 11a attached to the top of the suspension 12 and a cylinder 11b into which the piston 11a is fitted from below. In the figure, 11c is a cylinder 11
It is a spring for adjusting pressure provided in b.

By the way, when braking is performed while the vehicle is turning, the load difference between the front wheel on the inner wheel side and the rear wheel on the outer wheel side is reduced due to the movement of the load to the outer wheel side, and the front wheel on the outer wheel side and the rear wheel on the inner wheel side are reduced. The load difference with the wheel becomes large. Further, according to the above-described embodiment, since the brake pressure distributions of the front and rear wheels on the diagonal line are respectively controlled by the load sensing valves 7 according to the load difference between the front and rear wheels on the diagonal line, Appropriate brake pressure distribution can be performed even when turning.

The load sensing valve 7 is not limited to the one in the above embodiment, but various types conventionally known in Japanese Patent Publication No. 58-32058 can be used.

[0020]

As is apparent from the above description, according to the first aspect of the invention, the brake pressure can be appropriately distributed according to the front wheel load and the rear wheel load, and the load can be moved during turning. According to the invention of claim 2, the load sensing valve can be directly controlled according to the load difference between the front and rear wheels, and the control reliability is improved.

[Brief description of drawings]

FIG. 1 is a system diagram of an example of the device of the present invention.

2A is a diagram showing a relationship between a load detecting means and a load sensing valve, and FIG. 2B is a sectional view of the load detecting means.

[Fig. 3] Sectional view of the load sensing valve

4 (a) and 4 (b) are enlarged views of a main part showing the operation of the load sensing valve.

FIG. 5 is a diagram showing a distribution characteristic of brake pressure.

[Explanation of symbols]

1R, 1L Front wheel 2R, 2L Rear wheel 3 Brake 4 ₁ , 4 ₂ Brake piping 7 Load sensing valve 11 Load detection means

Claims (2)

[Claims] 1. A pair of brake pipes respectively connecting brakes for front and rear wheels on a diagonal line are provided, each load detecting means for detecting a load of each wheel is provided, and each brake pipe is provided with:
A brake pressure control device for a vehicle, comprising: a load sensing valve for controlling distribution of a brake pressure supplied to a brake of the front and rear wheels according to a detected amount of loads of the front and rear wheels on a corresponding diagonal line. 2. The load detection means is configured to generate a hydraulic pressure according to the load of each wheel, and the load sensing is performed on the differential pressure of the hydraulic pressure generated by the load detection means of the front and rear wheels on a diagonal line. The vehicle brake pressure control device according to claim 1, wherein the valve is input as a load signal.