JPH068952Y2 - 2 system brake hydraulic pressure control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a two-system brake hydraulic pressure control valve used in an automobile or the like and controlling hydraulic pressure distribution to front and rear wheels.

<Prior Art> As a conventional two-system brake hydraulic pressure control valve, for example, one disclosed in Japanese Patent Publication No. 61-40578 is known.

This hydraulic control valve includes a piston slidably accommodated in a valve housing, a spring member for urging the piston in a specific direction in the valve housing, a valve mechanism mounted on the upper part of the piston, and a lower part of the piston. It consists of a half-covered sleeve,
Liquid chambers are formed between the valve housing and the piston and between the valve housing and the sleeve, respectively, and the hydraulic pressure distribution between the front system and the rear system is controlled according to the load.

<Problems to be Solved> Since the fluid passage of the two-system brake is composed of two members, a sleeve forming the front fluid passage and a piston forming the rear fluid passage, the structure is complicated. Moreover, there is a problem to be solved that the manufacturing cost is high.

Further, a hydraulic control valve disclosed in Japanese Patent Laid-Open No. 49-98617 is also known.

This forms a first liquid chamber between the stepped portion of the valve housing and the corresponding stepped peripheral surface of the intermediate portion of the piston, and pierces the valve housing to form the second fluid passage and the third fluid passage. An internal passage communicating with the liquid passage is formed, and a valve mechanism for opening and closing the rear liquid passage is constituted by a ball valve.

However, in this hydraulic control valve, not only is it troublesome to form the internal passage, but it is also necessary to design the valve housing in a large size.

<Object of the present invention> The present invention has been made in view of the above points, and an object of the present invention is to provide a two-system brake hydraulic pressure control valve capable of simplifying the structure and reducing the cost.

<Structure of the Invention> Hereinafter, an embodiment of the invention will be described with reference to the drawings.

(A) Overall configuration of hydraulic control valve FIG. 1 shows an example of the hydraulic control valve.

1 is a valve housing.

Reference numeral 2 is a front system inlet that receives the hydraulic pressure from the front master cylinder, and 3 is a front system outlet that communicates with the front brake.

The front system outlet port 3 is suitable when the hydraulic pressure control valve is provided at the front of the vehicle. When the hydraulic control valve is provided at the rear of the vehicle, a branch fluid passage is provided in the fluid passage that connects the master cylinder and the front brake. , This branch liquid path to the front system inlet 2
The front system lead-out port 3 may be omitted by connecting to the.

The point is that the hydraulic pressure of the front system should act.

Reference numeral 4 is a rear system introduction port that receives the hydraulic pressure supply from the rear system master cylinder, and 5 is a rear system outlet port that communicates with the rear brake.

6 is a stepped small diameter hole, 7 is a stepped large diameter hole, 8 is a valve seat hole for mounting a valve seat described later, and these holes 6 to 8 are formed to communicate with each other in the valve housing 1. .

A piston 10 is slidably accommodated in the valve housing 1, and has a valve body 11 at its upper end.

A stepped surface 12 is formed on the peripheral surface of the piston 10 located in the stepped large-diameter hole 7, and a communication liquid passage 13 is opened in parallel with the axial direction of the piston 10.

The communicating liquid passage 13 always communicates between a second liquid chamber 61 and a third liquid chamber 62 described later.

Reference numeral 14 denotes a lower end portion formed on the lower end of the piston 10.

20 is a valve seat mounted in the valve seat hole 8.
A valve mechanism that connects and disconnects the rear liquid path is formed between the valve body 11 and the valve body 11.

Reference numeral 30 denotes a spring member, which biases the piston 10 upward in the drawing in the direction of opening the front valve mechanism.

Reference numeral 40 is a plug that closes the opening of the valve housing 1, and the lower end 14 of the piston 10 is inserted into a hole formed in the center.
Is slidably accommodated.

Sealing members 50, 51 and 52 are provided on the outer circumference of the piston 10, respectively.

An annular first liquid chamber 60 is formed between the valve housing 1 and the peripheral surface of the intermediate portion of the piston 10, and the first liquid chamber 60 communicates with the front system inlet port 2 and the front system outlet port 3, respectively. .

There is a second gap between the valve housing 1 and the peripheral surface of the upper portion of the piston 10.
Liquid chamber 61 is formed, and the second liquid chamber 61 communicates with the rear system outlet 5.

Further, a third liquid chamber 62 is formed between the valve housing 1 and the peripheral surface of the lower portion of the piston 10, and the third liquid chamber 62 communicates with the rear system inlet 4.

(B) Relation of pressure receiving surface of piston The relation of each pressure receiving surface acting on the piston 10 is required to satisfy the following requirements.

That is, the relationship between the pressure receiving surfaces acting on the piston 10 is as follows: in the first liquid chamber 60, the lower side> the upper side, the second liquid chamber 61 and the third liquid chamber 62, the second liquid chamber 61 side <the third side. Liquid chamber 62 side Effective pressure receiving area X of valve mechanism> Lower end portion 1 of piston 10
The pressure receiving area Y is set to 4.

Further, the pressure receiving area obtained by subtracting the pressure receiving area of the second liquid chamber 61 from the pressure receiving area of the third liquid chamber 62 is defined as A.

<Operation of the Invention> Next, the operation will be described.

(B) When both the front and rear hydraulic pressures are normal, the hydraulic pressure acting on the piston 10 is balanced except for the hydraulic pressure acting on the lower end portion 14.

Therefore, when the hydraulic pressure acting on the lower end portion 14 of the piston 10 overcomes the spring force of the spring member 30, the piston 10 descends and the valve element 11 is seated on the valve seat 20, temporarily closing the rear fluid passage. To do.

Then, the pressure receiving area X of the valve body 11 is larger than the pressure receiving area Y of the lower end portion 14, so that the piston 10 rises, the valve body 11 is separated from the valve seat 20, and the hydraulic pressure is fed to the rear brake. .

By repeating such an operation, the hydraulic pressure on the rear system outlet 5 side is reduced at a constant rate (X−Y) / X with respect to the hydraulic pressure increase of the master cylinder.

In addition, the breaking point hydraulic pressure that starts the pressure reducing action is the spring member 30.
If the spring force of is F, then F / Y.

(B) When the front system hydraulic pressure is lost When the hydraulic pressure of the first liquid chamber 60 is lost, the acting force acting on the piston 10 is the amount obtained by subtracting the pressure receiving area Y of the lower end portion 14 from the pressure receiving area A. Only upwards are larger.

Further, when the pressure receiving area A and the pressure receiving area Y are equal, the upward acting force is increased by the spring force of the spring member 30.

Therefore, the valve element 11 of the piston 10 is held in a state of being separated from the valve seat 20, the valve mechanism is always in the released state, and the hydraulic pressure of the master cylinder is directly fed to the rear brake.

<Other Embodiments> (FIG. 2) This embodiment will be described as an example applied to a system in which hydraulic pressure distribution to the front and rear wheels is controlled according to the load.

That is, the protruding shaft portion 1 is provided at the lower end portion 14 of the piston 10.
5 is formed, and the protruding shaft portion 15 penetrates the plug 40.

The tip of the protruding shaft portion 15 has a spring member 70 that responds to the load.
Is in contact with.

The spring member 70 urges the piston 10 in the upward direction of the drawing with a force corresponding to the load.

Since the piston 10 is biased upward by the spring force of the spring member 70, the spring member 30 installed in the third liquid chamber 62 can be omitted.

Structures and operations other than those described above are the same as those of the above-described embodiment, and therefore description thereof will be omitted.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be expected.

(A) Since the valve mechanism is composed of a non-ball valve (a valve seat mounted in a small-diameter stepped hole and a valve body formed at the upper end of the piston), the piston itself has a second liquid chamber and a third liquid chamber. A liquid passage communicating with the liquid chamber can be formed.

(B) Since the liquid passage can be formed in the piston, the machining is easier than in the case where the liquid passage is provided in the valve housing.
The valve housing can be designed compactly.

(C) Since the structure is simple and the number of constituent parts is small, the assemblability is improved and the manufacturing cost can be reduced.

[Brief description of drawings]

 FIG. 1: Vertical sectional view showing one embodiment of the hydraulic control valve of the present invention. FIG. 2: Vertical sectional view showing other embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] 1. A hydraulic control valve for forming a two-system brake fluid path of a front system and a rear system, and a valve housing having stepped holes of large diameter and small diameter inside, and slidably in the valve housing. The piston to be fitted, the stepped part of the stepped hole and the first liquid chamber of the front system formed between the stepped peripheral surface of the intermediate part of the corresponding piston, the small diameter part of the stepped hole and the piston Formed between the upper surface and the peripheral surface,
It is formed between the second liquid chamber communicating with the rear system outlet and the peripheral surface between the large diameter part of the stepped hole and the lower part of the piston,
A third liquid chamber communicating with the rear system introducing liquid passage, a liquid passage formed so as to penetrate in the axial direction of the piston, and communicating the second liquid chamber and the third liquid chamber, and a small diameter stepped hole It consists of a valve mechanism that opens and closes the rear fluid passage by attaching and detaching the valve element formed at the upper end of the piston to the valve seat attached to the A two-system brake hydraulic pressure control valve, wherein a pressure receiving area of a lower end portion of the piston is formed smaller than an effective pressure receiving area of the valve mechanism.