JP3273386B2 - Vehicle brake pressure control device - Google Patents

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 the distribution of brake pressure between front and rear wheels.

[0002]

2. Description of the Related Art Conventionally, as a vehicle brake pressure control device, as disclosed in Japanese Patent Publication No. 58-32058 and the like, a load for controlling distribution of brake pressure supplied to brakes of front and rear wheels according to rear wheel load. 2. Description of the Related Art There has been known an arrangement in which a sensing valve is provided to prevent locking of a rear wheel. In this case, 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 wheel, it is necessary to appropriately distribute the brake pressure according to the load of the front wheel and the load of the rear wheel. In addition, since the brake pressure of both the left and right rear wheels is controlled by a common load sensing valve, it is not possible to perform an appropriate brake pressure distribution corresponding to the load movement during turning. The present invention has been made in view of the above points, and it is an object of the present invention to provide a device capable of performing appropriate brake pressure distribution in accordance with the load of the front and rear wheels and capable of performing proper brake pressure distribution even when turning. The purpose is.

[0004]

In order to achieve the above object,
The present invention is, left, right front wheels and left, provided with a respective load detecting means for detecting a load of each wheel comprising a rear wheel of the right, left
The brake pressure supplied to the rear wheel brakes for the right front wheel and the rear left
Right front wheel load and left rear wheel detected by load detection means for wheels
Load sensor for the left rear wheel that controls pressure reduction according to the difference
Sing valve and brake pressure supplied to right rear wheel brake
Is detected by the load detection means for the front left wheel and the rear right wheel.
Reduce pressure control according to the difference between the load on the front wheel and the load on the right rear wheel
A right rear wheel load sensing valve is provided . In this case, each of the load detection means is configured to generate a hydraulic pressure according to the load of each wheel, and the right and left front wheel and the left
The differential pressure of the hydraulic pressure generated by the load detection means for the rear wheel
Input as load signal to load sensing valve for wheels
At the same time, it is desirable to input the pressure difference between the hydraulic pressures generated by the load detection means for the front left wheel and the rear right wheel to the load sensing valve for the rear right wheel as a load signal.

[0005]

According to the present invention, to increase the pressure reduction ratio of the brake pressure of the rear wheel when the load difference between the front and rear wheels is increased
Brake pressure distribution between front and rear wheels according to load difference between front and rear wheels
The rear wheel lock can be reliably prevented by performing appropriate control . Also, the front and rear wheels on one diagonal line , that is, the right front wheel
And the brake pressure distribution of the left rear wheel and the front and rear wheels on the other diagonal ,
That is, since the brake pressure distribution of the front left wheel and the rear right wheel is controlled by separate load sensing valves, the brake pressure reduction ratio of the rear wheel on the inner wheel side during the turn is increased to prevent locking, and the outer wheel is locked. The brake performance can be improved by reducing the pressure reduction ratio of the brake pressure on the rear wheel on the side.

[0006]

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 and is provided, and connects the output pipe 6 _and 62 of the pair of the master cylinder 6 interlocked with the brake pedal 5 at both the brake pipe 4 _1, 4 _2.

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

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

Each proportioning valve 9 ₁ , 9 ₂
A plunger 90 is provided to be inserted into each stepped hole formed in the valve casing 8, and an annular valve seat 91 is mounted on the bottom surface of the large diameter portion of the stepped hole.
At the left end of the figure, a valve element 92 to be inserted into the small diameter portion of the stepped hole is formed. According to the rightward movement of the plunger 90, the valve element 92 comes into contact with the valve seat 91 as shown in FIG. Thus, the communication between the inflow liquid chamber 93 formed by 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 leftward movement of the plunger 90, FIG. As shown in FIG.
Is separated from the valve seat 91 so that the inflow liquid chamber 93 and the outlet 94 communicate with each other through the groove 92a on the outer peripheral surface of the valve element 92 and the shaft hole 92b, and further, on 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, and the right end of the plunger 90 is inserted into the seal member 95 and the guide sleeve 96, and a spring is mounted on the right end of the plunger 90 via a seat 97a. The spring 97 presses the plunger 90 to the left opening side. The plunger 90 has its left-hand movement position regulated by a stopper 98 attached to the bottom of the small-diameter portion of the stepped hole. The plunger 90 has a piston portion 99 that is loosely inserted into the large-diameter portion of the stepped hole. , Plunger 9
At a predetermined left movement position of 0, the piston portion 99 is brought into contact with a projection 91a for securing a gap protruding from the right side surface of the valve seat 91.

The individual proportioning valves 9 ₁ , 9 ₂
Operates so as to control the output pressure at the outlet 94 to be reduced at the turning point with respect to the input pressure at the inflow liquid chamber 93, that is, at first, the plunger 90 is moved to the left by the urging force of the spring 97 and the output pressure is increased. It rises at the same pressure as the input pressure.
Is pressed to the right closing side by the output pressure acting on the left end face of the valve 92, and when the output pressure rises to a predetermined value and the pressing force to the closing side exceeds the urging force of the spring 97, the plunger 90 is moved. Rightward, the valve seat 91 is closed, and thereafter, even if the plunger 90 once moves leftward due to an increase in the input pressure, the plunger 90 moves rightward again due to the increase in the output pressure, and the valve seat 91 is closed. This operation is repeated. As a result, the output pressure is reduced by a predetermined ratio with respect to the input pressure and rises, and a breakpoint appears when the output pressure reaches the predetermined value.

Here, the first proportioning valve 9
₁ of the urging force of the spring 97 is set stronger than the biasing force of the second proportioning valve 9 _second spring 97, the first folding point value of proportioning valve 9 ₁ nuclear second
It is larger than that of the proportioning valve 9 _2. The first proportioning valve 9 _first outlet 9
4 together with communicating with the second proportioning valve 9 ₂ influent chamber 93 through the communicating passage 8c in the valve casing 8, a first proportioning valve 9 ₁ influent chamber 93 the input port 8a, second the outlet 94 of the proportioning valve 9 ₂ into communication respectively with the said output port 8b, intervened both proportioning valve 9 _1, 9 ₂ in series between the input port 8a and the output port 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 The pressure is controlled by the ratio,
As shown in, it appears a second folding point corresponding to the first folding point and folding point value of the first proportioning valve 9 ₁ corresponding to the breakpoint value of the second proportioning valve 9 _2.

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, the line a in FIG. In order to approximate the actual braking force line to the respective ideal braking force distribution curves, it is necessary to change each folding point according to the load difference between the front and rear wheels.

The load sensing valve 7 is provided with a biasing force for setting a turning point of the two proportioning valves 9 ₁ and 9 ₂ ,
That is, so that the biasing force of the both valve 9 _1, 9 ₂ springs 97, 97 may be variable, spring bearing 10 of the movable undergoing both said spring 97, 97 is provided to displace the spring bearing 10 Thereby, the folding point can be changed.

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

In this case, the load detecting means 11 may be constituted by a load cell or the like for generating an electric signal corresponding to the load, and the spring receiver 10 may be displaced by a solenoid. In order to improve this, it is desirable that the spring receiver 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 providing a load detecting means 11 for generating a hydraulic pressure according to a load at the top of a suspension 12 of each wheel, and for opposingly inputting the hydraulic pressure generated from the load detecting means 11 for the front and rear wheels on a diagonal line. 13 and the cylinder 13
The piston rod 13a is connected to the spring receiver 10 of the load sensing valve 7, and the load detecting means 11, 1
The spring receiver 10 is displaced in accordance with the pressure difference of the hydraulic pressure generated from the pressure sensor 1. As shown in FIG. 2B, the load detecting means 11 includes a piston 11a mounted on the top of the suspension 12 and a cylinder 11b which fits the piston 11a from below. 11c is a cylinder 11 in the figure.
This is a spring for pressure adjustment provided in b.

By the way, when braking is performed during turning of the vehicle, the load difference between the front wheel on the inner wheel side and the rear wheel on the outer wheel side is reduced by the load transfer to the outer wheel side, and the front wheel on the outer wheel side and the rear wheel on the inner wheel side are moved. The load difference with the wheel increases. According to the above embodiment, the brake pressure distribution of the front and rear wheels on the diagonal is controlled by each load sensing valve 7 according to the load difference between the front and rear wheels on the diagonal. Appropriate brake pressure distribution can also be performed during turning.

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

[0020]

As is apparent from the above description, according to the first aspect of the present invention, it is possible to perform an appropriate brake pressure distribution in accordance with the front wheel load and the rear wheel load, and to perform load movement during turning. According to the second aspect of the present invention, the load sensing valve can be directly controlled according to the load difference between the front and rear wheels, and the reliability of the control is improved.

[Brief description of the drawings]

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

FIG. 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 is a sectional view of a load sensing valve.

FIGS. 4A and 4B are enlarged views of main parts showing the operation of a load sensing valve.

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

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-81348 (JP, A) JP-A-5-147513 (JP, A) JP-A-4-81350 (JP, A) JP-A Sho 52-81 84363 (JP, A) JP-A-5-50914 (JP, A) JP-A-1-175959 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 8/26

Claims (2)

(57) [Claims] A load detecting means for detecting a load on each wheel, comprising left and right front wheels and left and right rear wheels, is provided, and a brake pressure to be supplied to a left rear wheel brake is provided . For right front wheel and left
The load on the right front wheel detected by the load detection means for the rear wheel and the rear left
Load control for left rear wheel that controls pressure reduction according to the difference from the load on the wheel
And the brake pressure supplied to the right rear wheel brake for the left front wheel and the right
The load on the left front wheel detected by the load detection means for the rear wheel and the right rear
Load control for the right rear wheel that controls pressure reduction according to the difference from the wheel load
A vehicular brake pressure control device , comprising a sensing valve . 2. Each of the load detecting means is configured to generate a hydraulic pressure corresponding to a load of each wheel, and is used for a right front wheel and a left rear wheel.
The differential pressure of the hydraulic pressure generated by the load detection means
When input as a load signal to the
2. The vehicle according to claim 1, wherein a differential pressure between hydraulic pressures generated by load detection means for the front left wheel and the rear right wheel is input to the load sensing valve for the rear right wheel as a load signal. Brake pressure control device.