JPH10329694A - Safety device of automobile brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To normally operate wheel brakes of all wheels when a brake master cylinder of either one system of a two-system type brake system is broken, and prevent the overturn accident and rear-end collision of an automobile by bias braking. SOLUTION: A first safety device 10 interrupts a hydraulic circuit connected to the reduced brake master cylinder when the hydraulic pressure of either one of a hydraulic circuit for right front wheel and a hydraulic circuit for left front wheel is reduced lower than a prescribed value, and transmits the hydraulic pressure commonly to the right front wheel and the left front wheel through the other hydraulic circuit. A second safety device 20 interrupts a hydraulic circuit connected to the reduced brake master cylinder when the hydraulic pressure of either one of a hydraulic circuit for right rear wheel and a hydraulic circuit for left rear wheel is reduced lower than a prescribed value, and transmits the hydraulic pressure commonly to the right rear wheel and the left rear wheel through the other hydraulic circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system for an automobile having a two-brake system, and more particularly, a failure occurs in a brake master cylinder of either one of the two-brake systems. In this case, the present invention relates to a vehicle brake safety device capable of operating the entire wheel brake normally.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 1, a conventional two-system vehicle brake system includes a pair of brake master cylinders each including a first brake cylinder and a second brake cylinder, and And wheel brakes (not shown) attached to the wheels (wheels). Here, each of the first brake cylinder (PC) and the second brake cylinder (SC) converts the depressing force of the brake pedal generated by the user's operation of the brake pedal into hydraulic pressure, and converts the converted hydraulic pressure. Wheel brakes (not shown) for the left front wheel (right front wheel) and right rear wheel (left rear wheel), and wheels not shown for the right front wheel (left front wheel) and left rear wheel (right rear wheel) connected through a hydraulic pipe. Each is transmitted to the brake.

Further, each of the wheel brakes includes a first brake cylinder (PC) and a second brake cylinder (PC).
The vehicle is stopped by braking each wheel by hydraulic pressure transmitted from a brake cylinder (SC) through a hydraulic pipe. As described above, the conventional two-system brake system separates the hydraulic circuit connected to the four wheels into two systems and uses one brake system even if one of the systems is damaged. Thus, the vehicle is braked. That is, in the conventional two-system brake system, if one of the brake master cylinders fails, the two wheel brakes connected thereto lose the braking force.
It is made to operate only with individual wheel brakes.

[0004] By the way, a difference in braking force between a front wheel and a rear wheel is generated in a vehicle due to the movement of a load during braking.
The braking forces of the other two wheel brakes that are normally operated are different from each other, and a rotational force in a certain direction of the vehicle body is generated, whereby the vehicle body loses balance and rolls over. There was a problem that a rear-end collision due to loss occurred. For example, as shown in FIG. 2 during braking,
When a failure occurs in the second brake cylinder (SC), hydraulic pressure is not transmitted to the right front wheel and the left rear wheel connected to the second brake cylinder (SC), so that the right front wheel and the left rear wheel are not transmitted. Loses the braking force, and the hydraulic pressure is transmitted only to the left front wheel and the right rear wheel connected to the first brake cylinder (PC) to generate the braking force.

[0005]

According to the prior art constructed as described above, since the load of the automobile is biased forward during braking, the braking force of the left front wheel is relatively smaller than the braking force of the right rear wheel. Therefore, as shown in FIG. 2, a rotational force is generated in a counterclockwise direction about the axis of the vehicle body, and a rear-end collision may occur due to overturning or loss of direction of the vehicle body.

Accordingly, the present invention has been made to solve the above various problems, and an object of the present invention is to
If a brake cylinder in one of the system brake systems fails, the vehicle brake safety can prevent the vehicle from overturning and rear-end collision due to partial braking by operating the wheel brakes of all wheels normally. It is to provide a device.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a hydraulic circuit for connecting a right front wheel to a left rear wheel and a hydraulic circuit for connecting a left front wheel to a right rear wheel. In the vehicle brakes which are separated into a system and respectively connected to a pair of brake master cylinders, when one of the hydraulic pressures in the hydraulic circuit of the right front wheel and the hydraulic circuit of the left front wheel is reduced to a predetermined value or less, A first safety device configured to cut off a hydraulic circuit connected to the reduced brake master cylinder, and to commonly transmit hydraulic pressure to the right front wheel and the left front wheel through another hydraulic circuit; When either one of the hydraulic circuit of the right rear wheel and the hydraulic circuit of the left rear wheel is reduced to a predetermined value or less, the brake master system having the reduced hydraulic pressure is reduced. Blocks the hydraulic circuit which is connected to the loaders, second, which is through other one of the hydraulic circuits to be commonly transmitted to hydraulic pressure to the right rear wheel and the left rear wheel
And a safety device.

Further, the first safety device of the present invention is configured to perform an operation of closing one of the hydraulic circuit of the right front wheel and the hydraulic circuit of the left front wheel. The first safety device hydraulic cutoff valve is operated in accordance with a hydraulic pressure difference between the hydraulic circuit for the safety device and the hydraulic circuit for the right front wheel and the hydraulic circuit for the left front wheel, and the hydraulic circuit for the right front wheel is A first safety device control valve configured to shut off a hydraulic circuit whose hydraulic pressure is relatively lower than a predetermined value in the hydraulic circuit of the left front wheel, and a control valve for the right front wheel and the first safety device. A hydraulic circuit between the hydraulic shut-off valves,
A first safety device connecting pipe configured to mutually communicate a hydraulic circuit between the left front wheel and the first safety device hydraulic shutoff valve.

The second safety device of the present invention is configured to perform an operation of closing one of the hydraulic circuit of the right rear wheel and the hydraulic circuit of the left rear wheel. The second safety device hydraulic shut-off valve is operated in accordance with a hydraulic pressure difference between the hydraulic circuit for the safety device and the hydraulic circuit for the right rear wheel and the hydraulic circuit for the left rear wheel. A second safety device control valve configured to shut off a hydraulic circuit whose hydraulic pressure is relatively lower than a predetermined value among a hydraulic circuit and a hydraulic circuit of the left rear wheel; A hydraulic circuit between a second safety device hydraulic cutoff valve and a second safety device connection pipe configured to mutually communicate a hydraulic circuit between the left rear wheel and the second hydraulic cutoff valve. It is characterized by having.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. FIG.
1 is a schematic block diagram of a two-system vehicle brake system to which the present invention is applied. As can be seen from the drawing, the vehicle brake system to which the present invention is applied has a first brake cylinder (PC). ) And a second brake cylinder (SC), a pair of brake master cylinders, a wheel brake (not shown) attached to each wheel,
Safety device (10) and a second safety device (20). Here, the first brake cylinder (PC) and the second brake cylinder (SC) convert the pedaling force of the brake pedal generated by the user's operation of the brake pedal into hydraulic pressure, respectively, and are converted. The hydraulic pressure is transmitted to a left front wheel and a right rear wheel (not shown) and a right front wheel and a left rear wheel (not shown) which are connected to each other through a hydraulic pipe.

Further, each of the wheel brakes is connected to the first brake cylinder (PC) and the second brake cylinder (PC).
The vehicle is stopped by braking each wheel by hydraulic pressure transmitted from a brake cylinder (SC) through a hydraulic pipe. Further, the first safety device (10) has one end connected to the hydraulic pipe for the right front wheel and the other end connected to the hydraulic pipe for the left front wheel, and the second safety device (20) has one end connected to the right rear wheel. And one end is connected to the hydraulic pipe on the left rear wheel side.

FIGS. 4A and 4B are structural views of the first safety device 10 and the second safety device 20 shown in FIG. ) Is a connecting pipe (11) for interconnecting the right front wheel direction hydraulic pipe and the left front wheel direction hydraulic pipe, and closing one of the right front wheel hydraulic pipe and the left front wheel hydraulic pipe. And a hydraulic shut-off valve (1) in response to a hydraulic pressure difference between the hydraulic pipe of the right front wheel and the hydraulic pipe of the left front wheel.
By operating 2), the control valve (13) configured to shut off the hydraulic pipe whose hydraulic pressure is relatively lower than the predetermined value is cut off.

The second safety device (20) further comprises a connecting pipe (21) for interconnecting the right rear wheel direction hydraulic pipe and the left rear wheel direction hydraulic pipe, the right rear wheel hydraulic pipe and the left side hydraulic pipe. A hydraulic shut-off valve (22) configured to perform an operation of closing one of the hydraulic pipes of the rear wheel, and a hydraulic pressure difference between the hydraulic pipe of the right rear wheel and the hydraulic pipe of the left rear wheel. And a control valve (23) configured to shut off a hydraulic pipe whose oil pressure is relatively lower than a predetermined value by operating the oil pressure cutoff valve (22) in response to the pressure.

Hereinafter, an example of the operation of the present invention configured as described above will be described in detail with reference to FIGS. First, when a failure such as brake fluid leakage occurs in the second brake cylinder (SC), the hydraulic pressure of the hydraulic pipe connected to the second brake cylinder (SC), that is,
The hydraulic pressure in the hydraulic pipe from the wheel brake (not shown) of the right front wheel to the wheel brake (not shown) of the left rear wheel is reduced.

At this time, the regulating valves (13, 23) are connected to a hydraulic pipe connected to the first brake cylinder (PC),
Operating the hydraulic shut-off valves (12, 22) toward the hydraulic pipe whose hydraulic pressure is relatively lower than a predetermined value in response to the hydraulic pressure difference of the hydraulic pipe connected to the second brake cylinder (SC). As a result, the second brake cylinder (S
C) and a predetermined position of a hydraulic pipe connecting the wheel brake of the right front wheel and a predetermined position of a hydraulic pipe connecting the second brake cylinder (SC) and the wheel brake of the left rear wheel. Thus, even if the brake fluid leaks from the second brake cylinder (SC), the hydraulic pressure in the hydraulic pipe from the wheel brakes of the right front wheel and the left rear wheel to the cutoff point of the hydraulic cutoff valves (12, 22) is increased. Is not further reduced, the hydraulic pressure supplied from the first brake cylinder (PC) is transmitted to the wheel brakes of the left front wheel and the right rear wheel, and the right front wheel is connected through connecting pipes (11, 21). And transmitted to the left rear wheel brake. Thus, when the driver operates a brake pedal (not shown) to apply braking, the pedaling force applied to the brake is converted into hydraulic pressure by the first brake cylinder (PC) and transmitted to the wheel brakes of the four wheels. Thus, the vehicle can be safely braked.

As described above, the present invention provides the first brake cylinder (P
When the hydraulic pressure is reduced due to a failure such as leakage of brake fluid from one of the brake cylinders (C) and the second brake cylinder (SC), the first safety device (10) and the second safety device (20) Breaks the hydraulic circuit connected to the brake cylinder whose hydraulic pressure has been reduced due to the failure, and transmits the hydraulic pressure of the hydraulic circuit that normally operates to all four wheels to safely brake the vehicle, thereby allowing the vehicle to perform partial braking. It is possible to prevent a capsizing accident, a rear-end collision accident and the like from occurring.

On the other hand, in the operation example of the present invention as described above, only the case where a failure occurs in the second brake cylinder (SC) has been described. However, those skilled in the technical field may It will be readily apparent that the invention operates identically in situations where a failure occurs in the brake cylinder (PC).

[0018]

As described above, according to the present invention, the hydraulic circuit connected to the brake cylinder whose hydraulic pressure has been reduced due to a failure is cut off, and the hydraulic pressure transmitted from the normally operating brake master cylinder is reduced by 4%. By transmitting all of the signals to the wheels to safely brake the vehicle, when a failure occurs in one of the brake master cylinders in one of the two-system brake system, it is possible to prevent the vehicle from overturning and rear-end collision due to partial braking. There is an excellent effect that can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a conventional typical two-system vehicle brake system.

FIG. 2 is an explanatory diagram for a failure state in FIG. 1;

FIG. 3 is a schematic block diagram of a two-system vehicle brake system to which the present invention is applied.

4 (a) and 4 (b) are structural diagrams of the first safety device and the second safety device shown in FIG.

FIG. 5 is an explanatory diagram of an operation state of the present invention.

6 (a) and 6 (b) are operation state diagrams of the first safety device and the second safety device shown in FIG. 5;

[Explanation of symbols]

 Reference Signs List 10 first safety device 11, 21 connecting pipe 13, 23 regulating valve 20 second safety device 12, 22 hydraulic shutoff valve

Claims (3)

[Claims] 1. A hydraulic circuit connecting the right front wheel to the left rear wheel and a hydraulic circuit connecting the left front wheel to the right rear wheel are separated into respective systems and connected to a pair of brake master cylinders. In the vehicle brake, when one of the hydraulic circuits of the right front wheel hydraulic circuit and the left front wheel hydraulic circuit is reduced to a predetermined value or less, the hydraulic circuit connected to the reduced brake master cylinder is shut off. A first safety device configured to commonly transmit hydraulic pressure to the right front wheel and the left front wheel through another hydraulic circuit; and a hydraulic circuit for the right rear wheel and a hydraulic circuit for the left rear wheel. If one of the hydraulic pressures falls below a predetermined value, the hydraulic circuit connected to the reduced brake master cylinder is shut off, and the other hydraulic circuit is disconnected. Through to motor vehicle safety brake, characterized in that it comprises a second safety device and which is adapted to transmit commonly hydraulic pressure to the right rear wheel and the left rear wheel. 2. The first safety device according to claim 1, wherein the first safety device is configured to perform an operation of closing one of a hydraulic circuit of the right front wheel and a hydraulic circuit of the left front wheel. A hydraulic shut-off valve, operating the first safety device hydraulic shut-off valve in accordance with a hydraulic pressure difference between the hydraulic circuit for the right front wheel and the hydraulic circuit for the left front wheel to operate the hydraulic circuit for the right front wheel and the left front wheel. A first safety device control valve configured to shut off a hydraulic circuit whose oil pressure is relatively lower than a predetermined value in the hydraulic circuit; a right front wheel and the first safety device hydraulic shutoff valve And a first safety device connection pipe configured to mutually communicate a hydraulic circuit between the left front wheel and the first safety device hydraulic cutoff valve. Item 1. A safety device for an automobile brake according to item 1. 3. A second safety device configured to perform an operation of closing one of a hydraulic circuit of the right rear wheel and a hydraulic circuit of the left rear wheel. A hydraulic cutoff valve for the device, and a hydraulic circuit for the right rear wheel by operating the second safety device hydraulic cutoff valve in accordance with a hydraulic pressure difference between the hydraulic circuit for the right rear wheel and the hydraulic circuit for the left rear wheel. And a second safety device control valve configured to shut off a hydraulic circuit whose hydraulic pressure is relatively lower than a predetermined value in the hydraulic circuit of the left rear wheel, and the right rear wheel and the second A hydraulic circuit between the safety device hydraulic cutoff valves, and a second safety device connection pipe configured to mutually communicate a hydraulic circuit between the left rear wheel and the second safety device hydraulic shutoff valve. 3. The safety of a vehicle brake according to claim 1, further comprising: Apparatus.