JPH0222376Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dual-system braking system for automobiles.

In order to improve safety, automobiles are required to have two systems of braking equipment.
Some dual-system brake systems have left and right rear brake systems connected to independent hydraulic circuits. Furthermore, in automobiles, an electronically controlled skid control device (also simply referred to as an anti-skid device) has been developed, which effectively prevents skidding of wheels (usually rear wheels) during sudden braking. By the way, in this electronically controlled skid control device, an electronically controlled and expensive actuator is disposed in the hydraulic circuit leading to the rear brake device, and this actuator operates according to the rotational state of the rear wheel. controlled to control the hydraulic pressure to the rear brake system. Therefore, when this electronically controlled skid control device is employed in the above-mentioned type of dual-system brake system, it is necessary to install an expensive actuator in each hydraulic circuit, resulting in high costs.

This invention was made with attention to this point,
The purpose is to provide an inexpensive dual-system brake system with a wheel skid prevention function.

An embodiment of the present invention will be described below based on the drawings. FIG. 1 shows an example in which the present invention is applied to a diagonal dual-system brake system 10 for an automobile. In this brake system 10, a front brake system 11 on the left and a rear brake system 12 on the right It is connected to the first fluid chamber 13a of the master cylinder 13 as a system, and also includes a front brake device 14 on the right side and a rear brake device 15 on the left side.
is connected to the second liquid chamber 13b of the master cylinder 13 as a second system.

However, in this brake device 10,
An actuator 20 of a known electronic skid control device is disposed in the hydraulic pressure circuit a leading to the rear brake device 12 in the hydraulic pressure circuit A of the first system, and a rear brake in the hydraulic pressure circuit B of the second system is disposed. A modulator valve 30 is arranged in the hydraulic circuit b leading to the device 15. As is well known, the operation of the actuator 20 is electronically controlled according to the rotational state of the right rear wheel, and controls (increases and decreases) the hydraulic pressure generated in the hydraulic pressure circuit _a1 communicating with the rear brake device 12. )do.

As shown in FIGS. 1 and 2, the modulator valve 30 consists of a housing 31, a balance piston mechanism 30A and a bypass valve 30B that are installed in parallel in the housing 31. The housing 31 has a first port 31a and a second port 3 that communicate with each other and constitute a part of the hydraulic circuit b.
1b (rear brake device 15 through hydraulic circuit b ₁₎
), and a third port 31c and a fourth port 31d that communicate with the hydraulic circuit _a1 through the hydraulic circuit c. Balance piston mechanism 30
A is the balance piston 32 and the ball valve body 33
, a compression coil spring 34 that biases the balance piston 32 to the left in the figure, and a compression coil spring 35 that biases the ball valve body 33 to the right in the figure.
The repulsive force is greater than that of 5. The balance piston 32 is fitted into the housing 31 so as to be slidable in the axial direction, and receives the liquid pressure in the liquid chamber R1 communicating with the third port 31c on the right side, and receives the liquid pressure in the liquid chamber R1 communicating with the third port _31c on the left side.
In response to the hydraulic pressure in the liquid chamber R ₂ communicating with the port 31b, it moves to the right according to the hydraulic pressure difference in both the liquid chambers R ₁ and R ₂ .
When the liquid pressures in both liquid chambers R ₁ and R ₂ are substantially equal, the balance piston 32 is positioned as shown in the figure by engaging the stepped portion 31e of the housing 31 with its portion 32a. The ball valve body 33 is removably engaged with the balance piston 32, and when the balance piston 32 is positioned as shown in the figure, the ball valve body 33 is separated from the valve seat 31f provided in the housing 31 and is connected to the first port 31a and the first port 31a. The two ports 31b are communicated through the valve seat 31f, and when the balance piston 32 moves to the right, it seats on the valve seat 31f and blocks the communication between the first port 31a and the second port 31b.

The bypass valve 30B is a valve that bypasses the above-described valve seat 31f and opens and closes a bypass passage 31g that communicates the first port 31a and the second port 31b,
The valve body 36 and the valve body 36 shown on the left side (opening direction)
It consists of a compression coil spring 37 that biases the piston 38, and a stepped piston 38. The stepped piston 38 is fitted into the housing 31 so as to be slidable in the axial direction, and its large diameter portion is exposed to the liquid chamber _R3 communicating with the fourth port 31d, and its small diameter portion is exposed to the valve body 36. is in contact with the back of the In this bypass valve 30B, when no hydraulic pressure is applied to the hydraulic chamber R ₃ during non-braking and braking (when the first system hydraulic pressure circuit A fails), the valve body 36 moves into the bypass passage as shown in the figure. 31
g is open and during braking when hydraulic pressure is applied to the liquid chamber R ₃ (when both hydraulic pressure circuits A and B are normal), the valve body 36 opens the valve seat 3 provided in the housing 31.
1h and close the bypass passage 31g.

In the brake device 10 configured in this way, when the brake pedal 16 is depressed when both hydraulic pressure circuits A and B are normal, approximately the same hydraulic pressure is generated in both the hydraulic chambers 13a and 13b of the master cylinder 13, and each hydraulic pressure is The pressure is applied to the pressure circuits A and B, and applied to each of the brake devices 11, 12, 14, and 15, respectively, to brake the vehicle. At this time, fluid pressure is also applied to the fluid chamber R ₃ of the modulator valve 30, and the stepped piston 38 is pushed to the right due to the difference in pressure receiving area, pushing the valve body 36 to the right, is seated on the valve seat 31h and closes the bypass passage 31g, so the first port 31a and the second port 31b communicate only through the valve seat 31f.

By the way, when the actuator 20 operates during this braking, the hydraulic pressure in the hydraulic pressure circuit _a1 leading to the rear brake device 12 is controlled to be reduced, and this reduced hydraulic pressure is applied to the modulator valve 30 through the hydraulic pressure circuit c. It is also applied to the liquid chamber _R1 , and the balance piston 32 moves to the right due to the liquid pressure difference in both the liquid chambers _R1 and _R2 .
In the early stage, the ball valve 33 seats on the valve seat 31f and closes the communication between the ports 31a and 31b, and in the latter stage, the liquid pressure in the liquid chamber _R2 is reduced.
This reduced hydraulic pressure is applied to the rear brake device 15 through the second port 31b and the hydraulic pressure circuit _b1 . At this time, the liquid pressure in the liquid chamber _R3 is also reduced, but the stepped piston 38 does not move because it covers this pressure reduction due to the difference in its pressure receiving area, and the bypass passage 31g is maintained in a closed state.

Further, in this brake device 10, when the first hydraulic pressure circuit A fails, the modulator valve 30
No hydraulic pressure is applied to both liquid chambers R ₁ and R ₃ , and during braking, the ball valve 33 is seated on the valve seat 31 f, and the valve body 36 is separated from the valve seat 31 h and the bypass passage 3 is closed.
Keep 1g open. Therefore, at this time, the hydraulic pressure circuit _b1 is not depressurized and cut off, and the braking force is ensured.

In the above embodiment, the hydraulic pressure in the hydraulic pressure circuit _a1 is applied to the hydraulic chamber _R3 of the modulator valve 30, but when implementing the present invention, an actuator is applied to the hydraulic chamber _R3 . The configuration may be such that the hydraulic pressure in the hydraulic circuit between the master cylinder 13 and the master cylinder 20 is applied.

In addition, the present invention is not limited to the above-mentioned embodiment, and the present invention is not limited to the above-mentioned embodiment. It goes without saying that this can be implemented in the same way for dual-system brake systems connected by hydraulic pressure circuits of other systems, as well as for various dual-system brake systems in which the left and right rear brake systems are each connected to independent hydraulic pressure circuits. The apparatus can also be modified as appropriate.

In summary, in the present invention, in the above-mentioned two-system brake system, the actuator of the electronic skid control device is disposed in the hydraulic pressure circuit leading to the rear brake system in the first system hydraulic circuit of the two-system brake system. Further, a modulator valve is disposed in the hydraulic pressure circuit leading to the rear brake device in the second system hydraulic pressure circuit, and the modulator valve is provided with the actuator when the first system hydraulic pressure circuit is normal. The rear brake device of the second system is operated by the difference between the hydraulic pressure applied to the rear brake device of the first system and the hydraulic pressure applied to the rear brake system of the second system. It has a built-in balance piston mechanism that controls the hydraulic pressure applied to the system and shuts off the hydraulic pressure circuit leading to the rear brake device of the second system when the front first system hydraulic circuit fails, and also has a balance piston mechanism for this mechanism. Liquid that is provided in parallel and closes when the first hydraulic pressure circuit is normal, opens when the first hydraulic pressure circuit fails, bypasses the balance piston mechanism, and is shut off by the mechanism. It is unique in that it has a built-in bypass valve that allows communication between the pressure circuits. As a result, it is possible to obtain the same effect as using two actuators by using one actuator and one inexpensive modulator valve, without using two expensive actuators. can be constructed at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention;
FIG. 2 is an enlarged longitudinal sectional view of the modulator valve shown in FIG. 1. Explanation of symbols, 10... Dual brake system, 12... Right rear brake device, 15...
Left rear brake device, 20...actuator, 30...modulator valve, 30A...balance piston mechanism, 30B...bypass valve, A
...First system hydraulic pressure circuit, a...Hydraulic pressure circuit leading to the rear brake device in the first system hydraulic pressure circuit, B...
...Second hydraulic pressure circuit, b...Hydraulic pressure circuit leading to the rear brake device in the second hydraulic pressure circuit.

Claims (1)

[Scope of utility model registration request] In a two-system brake system for an automobile in which the left and right rear brake systems are connected to independent hydraulic circuits, electronic control is performed in the hydraulic pressure circuit leading to the rear brake system in the first hydraulic pressure circuit of the two-system brake system. An actuator for the skid control device is disposed, and a modulator valve is disposed in the hydraulic pressure circuit leading to the rear brake device in the second hydraulic pressure circuit, and the modulator valve is connected to the first When the system hydraulic pressure circuit is normal, the hydraulic pressure is controlled by the operation of the actuator and is activated by the difference between the hydraulic pressure applied to the rear brake device of the first system and the hydraulic pressure applied to the rear brake device of the second system. a balance piston mechanism that controls the hydraulic pressure applied to the rear brake device of the second system and shuts off the hydraulic pressure circuit leading to the rear brake device of the second system when the first hydraulic pressure circuit fails. In addition to being built in, a valve is provided in parallel to this mechanism and closes when the first system hydraulic pressure circuit is normal, and opens when the first system hydraulic pressure circuit fails, bypassing the balance piston mechanism. A two-system brake system for an automobile, characterized in that it has a built-in bypass valve that connects a hydraulic circuit that is shut off by the same mechanism.