JP2518814Y2 - Brake fluid pressure control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a brake fluid pressure control valve, for example, a brake fluid pressure control valve for controlling the brake fluid pressure of a vehicle.

(Prior Art) As a conventional brake fluid pressure control valve, for example,
There is one as shown in Fig. 7. In FIG. 5, reference numeral 1 is a brake fluid pressure control valve, and the brake fluid pressure control valve 1 is a piston 2 and an inlet port 4 connected to a master cylinder 3.
And a cylindrical housing 7 having an outlet port 6 connected to the rear wheel cylinder 5 and slidably supporting the piston 2 so that one end of the piston 2 projects into the atmosphere. The annular valve member 8 is supported in the housing 7 and can be brought into contact with the piston 2 and separated from the piston 2 in accordance with the sliding movement of the piston 2.

The inlet port 4 and the outlet port 6 communicate with each other via a liquid passage 9 formed by the housing 7 and the piston 2. As shown in FIG. 7, when the valve head 2a of the piston 2 and the valve seat portion 8a of the valve member 8 come into contact with each other, the liquid passage 9 is disconnected from the liquid passage 9, and as shown in FIG. , Piston 2
When the valve head 2a and the valve seat 8a of the valve member 8 are separated from each other, the liquid passage 9 can communicate with each other. The spring 10 biases the piston 2 so as to separate the valve head 2a from the valve seat portion 8a, and when the brake fluid pressure control valve 1 is in the inoperative state, the valve head 2a and the valve seat portion 8a are separated from each other. The hydraulic pressure from the master cylinder 3 side is directly transmitted to the rear wheel cylinder 5 side. When the brake pedal is depressed, the hydraulic pressure in the master cylinder 3 increases, and when the hydraulic pressure on the rear wheel cylinder 5 side reaches a specified value, a pressing force against the spring 10 is generated in the piston 2 and the piston 2 moves inside the housing 7. Sliding on the valve head 2a opens and closes the liquid passage 9, and the master cylinder 3
The hydraulic pressure on the rear wheel cylinder 5 side is controlled to be reduced with respect to the hydraulic pressure on the rear wheel cylinder side.

(Problems to be solved by the invention) However, in such a brake fluid pressure control valve, when the brake pedal 3A is suddenly depressed and the fluid pressure in the master cylinder 3 suddenly rises, the brake fluid in the operating state is activated. In the pressure control valve 1, when the brake fluid passes near the valve member, vibration of the brake fluid pressure occurs, an abnormal noise is generated, and the vibration of the brake fluid pressure is transmitted to the brake pedal 3A. There are problems that damage it.

Therefore, the present invention has been made in view of such a conventional problem, and the throttle amount of the first liquid passage before passing through the valve member is changed to the throttle amount of the second liquid passage after passing through the valve member. By making the amount larger than the throttle amount, the gradient of the hydraulic pressure in the throttle portion of the second liquid passage is reduced, the flow of the brake fluid passing through the second liquid passage is made smooth, and the flow from the first liquid passage is reduced. By significantly limiting the brake fluid pressure control valve, the brake fluid pressure vibration and abnormal noise can be significantly suppressed even when the brake pedal is suddenly depressed due to sudden stop. The purpose is to do.

(Means for Solving the Problems) A brake fluid pressure control valve according to the present invention has a piston, an inlet port connected to a master cylinder, and an outlet port connected to a rear wheel cylinder, and one end of the piston is at atmospheric pressure. A housing for slidably supporting the piston so as to project into the housing, and a valve member supported in the housing and capable of contacting the piston and separating from the piston according to the sliding of the piston. The port and the outlet port communicate with each other through the liquid passage formed by the housing and the piston, and when the piston and the valve member come into contact with each other, the communication of the liquid passage is blocked, and when the piston and the valve member are separated from each other, the liquid passage communicates with each other. In the brake fluid pressure control valve, the fluid passage includes a first fluid passage between the inlet port and the valve member, an outlet port, and the valve member. And a second liquid passage between the first liquid passage and the second liquid passage between the first liquid passage and the second liquid passage.

(Operation) In the brake fluid pressure control valve according to the present invention, since the throttle amount of the first fluid passage is made larger than the throttle amount of the second fluid passage, the gradient of the fluid pressure in the throttle portion of the second fluid passage is increased. Becomes smaller, the flow of the amount of brake fluid passing through the second fluid passage becomes smooth, and the flow from the first fluid passage is significantly restricted. Therefore, the smooth flow passing through the second liquid passage is not disturbed, and the advantageous effect that the flow of the brake fluid in the vicinity of the valve member can be reliably rectified is obtained. Therefore, even when the brake pedal is suddenly depressed due to a sudden stop or the like, it is possible to significantly suppress the hydraulic pressure vibration of the brake fluid and the generation of abnormal noise.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show a first example of a brake fluid pressure control valve according to the present invention.
It is a figure showing an example.

First, the configuration will be described. In FIG. 1, reference numeral 11 is a brake fluid pressure control valve, and the brake fluid pressure control valve 11 has a rod-shaped piston 12 having a small diameter neck portion in the axial center portion,
It has an inlet port 14 connected to the master cylinder 13 and an outlet port 16 connected to the rear wheel cylinder 15, and slidably supports the piston 12 so that one end 12a of the piston 12 projects into the atmosphere on the side of the opening 17a. Cylindrical housing 17
And have. 18 is an annular valve member, the valve member 18 is made of an elastic member, the outer periphery is supported in the housing 17,
The piston 12 can be brought into contact with the piston 12 and separated from the piston 12 according to the sliding movement of the piston 12.
Inlet port 14 and outlet port 16 are cylindrical housings 17
And a rod-like shape and a piston 12 communicate with each other through a liquid passage 20.

The liquid passage 20, as shown by the alternate long and short dash line 12A in FIG.
When the valve head 12b of the piston 12 and the valve seat portion 18a of the valve member 18 come into contact with each other, the communication of the liquid passage 20 is cut off, and as shown in FIG. 2, the valve head 12b of the piston 12 and the valve member 18 are closed. When separated from the valve seat portion 18a, the liquid passage 20 can communicate with each other. Reference numeral 18b denotes a plurality of protrusions arranged apart from each other in the circumferential direction, and a gap between the protrusions 18b forms a liquid passage 20.

The liquid passage 20 is composed of a first liquid passage 20A between the inlet port 14 and the valve member 18 and a second liquid passage 20B between the outlet port 16 and the valve member 18.

Reference numeral 21 denotes a spring, and the spring 21 is pressed by the pressing plate 23 shown in FIG. 1 to urge the piston 12 so as to separate the valve head portion 12b from the valve seat portion 18a. Reference numeral 24 denotes a lid, and the lid 24 slidably holds one end 12a of the piston 12 protruding into the atmosphere in the opening 17a of the housing 17, and an opening of the housing 17 by a stop ring 25 engaging with the housing 17. It is fixed in 17a and applies a pressing force to the holding plate 23. 27 and 28 are seal rings.

Reference numeral 30 denotes a flange, and the flange 30 is integrally provided on the outer peripheral portion of the piston 12 forming the second liquid passage between the inlet port 14 and the valve member 18. Outer peripheral surface 30a of flange 30
Is provided in the vicinity of the inner peripheral surface 17b of the housing 17 facing the outer peripheral surface 30a, and the outer peripheral surface 30a and the inner peripheral surface 17b form a first throttle portion 31. The first throttle portion 31 has a first throttle amount v ₁ determined by the area of the gap between the outer peripheral surface 30a and the inner peripheral surface 17b and the axial length of the flange 30. In general, the throttle amount v is so large that when a certain hydraulic pressure P is applied to the throttle portion, the smaller the amount of brake fluid passing per unit time, that is, the harder it is for the brake fluid to pass.

In addition, between the outlet port 16 and the valve member 18, the outlet port
The outer peripheral surface 12e of the piston 12 in the vicinity of 16 and the inner peripheral surface 17c of the housing 17 in the vicinity of the opening 16a of the outlet port 16 to the liquid passage 20 form a second throttle portion 32. The second throttle 32 has an area of a gap between the outer peripheral surface 12e and the inner peripheral surface 17c, and the valve head 12
It has a second throttle amount v ₂ of the second liquid passage 20B determined by the distance from the contact portion between b and the valve seat portion 18a to the opening 16a of the outlet port 16. The first aperture amount v ₁ of the first aperture portion 31 is set to be larger than the second aperture amount v ₂ of the second aperture portion 32. That is, the amount of the brake fluid flowing through the first throttle portion 31 is significantly limited, the brake fluid does not easily flow, and the gradient of the hydraulic pressure of the brake fluid is large. On the other hand, the second throttle unit 32 is
The amount of brake fluid that passes through is loosely regulated, the brake fluid easily flows, and the gradient of the hydraulic pressure of the brake fluid is also reduced.

 Next, the operation will be described.

In the brake fluid pressure control valve of the present invention, when the brake pedal is suddenly depressed due to a sudden stop or the like, the brake fluid from the master cylinder 13 flows into the first fluid passage 20A from the inlet port 14 and has a large first throttle amount. The flow rate is significantly limited through the first throttle portion 31 having v ₁ , then passes between the valve seat portion 18a and the valve head portion 12b, and then passes through the second throttle portion 32. The second aperture amount v ₂ of the second aperture portion 32 is the first aperture amount of the first aperture portion 31.
Since it is smaller than v _1, the gradient of the hydraulic pressure when the brake fluid whose fluid amount is already limited by the first throttle portion 31 passes through the second throttle portion 32 is small, and a sufficient fluid amount easily passes. Therefore, the brake fluid passing through the vicinity of the valve member 18 and passing through the second throttle portion 32 smoothly flows and is rectified. Therefore, the generation of vibration of the brake fluid pressure is suppressed, the piston 12 and the valve member 18 are not vibrated, and the generation of abnormal noise is significantly reduced.

 Next, a second embodiment of the present invention will be described.

3 and 4 are the second part of the brake fluid pressure control valve according to the present invention.
It is a diagram showing a main part of a brake fluid pressure control valve 41 of the embodiment,
The same components as those in the first embodiment are denoted by the same reference numerals.

In the second embodiment, the first brake fluid pressure control valve 41
In the first throttle portion 43 formed in the liquid passage 20A, the first liquid passage 20A communicates with a part of the outer peripheral portion 30b of the flange 30 in the circumferential direction in the axial direction of the piston 12 from the inlet port 14 side to the valve member 18 side. When the outer peripheral surface 30a of the flange 30 is provided in a notch shape so that the outer peripheral surface 30a of the flange 30 is extremely close to the inner peripheral surface 17a of the housing 17 facing the outer peripheral surface 30a and slidable. And the first aperture amount v ₃ of the first aperture portion 43 is equal to the second aperture portion 32.
It is designed to be larger than the aperture amount v _{2 of} .

The configuration other than the above is the same as that of FIG. 1, and the operation and effect are also the same.

(Effect) As described above, according to the present invention, the throttle amount of the first liquid passage before passing the valve member is made larger than the throttle amount of the second liquid passage after passing the valve member. Since the gradient of the hydraulic pressure in the throttle portion of the second liquid passage becomes small, the flow of the brake fluid passing through the second liquid passage becomes smooth and the flow from the first liquid passage is significantly restricted. Since the smooth flow passing through the second liquid passage is not disturbed, the flow of the brake fluid in the vicinity of the valve member can be reliably rectified. Therefore, even when the brake pedal is suddenly depressed due to a sudden stop or the like, it is possible to significantly suppress the hydraulic pressure vibration of the brake fluid and the generation of abnormal noise.

[Brief description of drawings]

1 and 2 are views showing a first embodiment of a brake fluid pressure control valve according to the present invention. FIG. 1 is a cross-sectional view showing the entire structure thereof, and FIG. 2 is an enlarged cross-sectional view of its essential parts. . FIGS. 3 and 4 are views showing a second embodiment of the brake fluid pressure control valve according to the present invention. FIG. 3 is a sectional view of an essential part thereof, and FIG. 4 is an IV of FIG.
FIG. 4 is a sectional view taken along the line IV-IV. 5 to 7 are views showing a conventional brake fluid pressure control valve, FIG. 5 is a cross-sectional view showing the entire structure thereof, and FIGS. 6 and 7 are enlarged cross-sectional views of the relevant parts thereof. 11, 41 …… Brake fluid pressure control valve, 12 …… Piston, 13…
… Master cylinder, 14 …… Inlet port, 15 …… Rear wheel cylinder, 16 …… Outlet port, 17 …… Housing,
18 ... Valve member, 20 ... Liquid passage, 20A ... First liquid passage, 20B
...... Second liquid passage, 31, 43 ...... First throttle part, 32 ...... Second throttle part, v ₁ , v ₃ ...... First throttle amount, v ₂ ...... Second throttle amount.

Claims (1)

(57) [Scope of utility model registration request] 1. A housing having a piston, an inlet port connected to a master cylinder, and an outlet port connected to a rear wheel cylinder, and slidably supporting the piston such that one end of the piston projects into the atmosphere. And a valve member supported in the housing and capable of abutting and separating from the piston in response to sliding of the piston, the inlet port and the outlet port defining a liquid passage formed by the housing and the piston. When the piston and the valve member come into contact with each other, the communication of the liquid passage is cut off, and when the piston and the valve member are separated from each other,
In the brake fluid pressure control valve in which the fluid passage communicates, the fluid passage includes a first fluid passage between the inlet port and the valve member and a second fluid passage between the outlet port and the valve member,
A brake fluid pressure control valve, wherein a throttle amount of the first fluid passage is larger than a throttle amount of the second fluid passage.