JPH10331978A - Cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap reduced in the number of part items so as to facilitate fitting work to an inner hole and prevented from the generation of chips caused by the damage of the inner hole at the time of press-fitting while ensuring sealing force equal to a conventional cap. SOLUTION: A cap part 41B covering an opening part 36 of an inner hole 30 formed in a housing 21, and a cylindrical part 41A fitted into the inner hole 30 are integrally formed of a single member, and a coat softer than the material of the cylindrical part 41A and the peripheral wall of the inner hole 30 is formed at least at the outer peripheral surface of the cylindrical part 41A. A cap 41 can therefore be fitted to the opening part 36 without damaging the peripheral wall of the inner hole 30 at the time of press-fitting the cap 41, and since the cap 41 is formed of the single member, the cap 41 can be easily fitted. Sealing force equal to a conventional cap can be obtained by the action of the coat of the press-fitted cylindrical part 41A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap which is attached to an opening of an inner hole and covers the opening to prevent foreign matter from entering the inner hole.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No.
No. 42454. FIG. 2 shows the cap described in the above publication, which will be described below.

[0003] Conventional caps are generally designated by 1;
It comprises a plastic cap body 2 and a rubber seal member 3 mounted on the outer periphery of a hanging portion 2A of the cap body 2. The cap 1 of this conventional example is attached so as to cover the opening 6 of the inner hole 5 formed in the housing 4 of the proportioning valve for controlling the supply of brake fluid pressure from the master cylinder to the wheel cylinder, although not shown. The sealing member 3 is pressed against the peripheral wall of the inner hole 5 to obtain a sealing action. A cylindrical member 8 is fitted into the inner hole 5 via a sealing member 9 below the cap 1, and is prevented from falling off by a retaining member 13. The piston 10 for controlling the opening and closing of the control valve is provided with a cylindrical member 13.
Is slidably fitted to the inner hole 13a through the sealing member 11, and when the liquid pressure in the liquid chamber 15 becomes higher than a predetermined pressure, the upper part of the drawing is opposed to the spring force of the spring 14. To reduce the brake fluid pressure supplied to the wheel cylinder (not shown) (rear wheel side). Cap 1 and piston 10
Has a sufficient volume that does not affect the movement of the piston 10.

[0004]

The conventional cap 1 is
Since it is composed of two members, the cap body 2 and the seal member 3, an assembling operation of these two members is necessary when the cap member 2 is attached to the opening 6. That is, assembling work increases as the number of parts increases. In order to solve this, it is conceivable to integrate the cap body 2 and the sealing member 3.
However, it is difficult to integrate them due to their different hardness.

On the other hand, as another conventional technique, a technique is known in which a cap is formed of a single member made of rubber or metal, and this is press-fitted into an opening of an inner hole. However, in the case of a conventional cap made of general-purpose rubber, settling or swelling occurs due to the adhesion of the brake hydraulic fluid, and the desired sealing force cannot be secured. In addition, in the case of a conventional metal cap, the wall surface of the inner hole abutting on the hanging portion of the cap at the time of press-fitting may be damaged, and chips generated at this time may enter the inner hole and have a great effect on equipment. There is a problem that there is.

Accordingly, the present invention has been made in view of the above problems, and has been made to reduce the number of parts to facilitate the work of mounting on the inner hole, and to prevent the generation of chips due to damage to the inner hole at the time of press fitting. It is another object of the present invention to provide a cap capable of securing the same sealing force as that of the conventional one.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a housing having a cover for covering an opening of an inner hole formed in a housing, and a cylindrical portion fitted into the inner hole. In the cap for shutting off the space between the lid and the tubular portion, the lid and the tubular portion are integrally formed with a single member, and the tubular portion is a press-fit portion to the inner hole, and is pressed against at least the peripheral wall of the inner hole. The problem is solved by a cap characterized in that a coating softer than the material of the cylindrical portion and the material of the peripheral wall is formed on the outer peripheral surface of the cylindrical portion.

According to the present invention, the cap is composed of a single component, the number of components is reduced, the work of mounting the cap on the opening is facilitated, and at least the outer peripheral surface of the cylindrical portion of the cap which is pressed against the peripheral wall of the inner hole. By forming a coating softer than the material of the cylindrical portion and the material of the peripheral wall of the inner hole, the generation of chips due to damage to the inner hole during press-fitting of the cap is prevented. After the press-fitting, a sealing action can be obtained by the coating, and a dust sealing action can be performed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a two-portion proportioning valve 20 in which a cap according to the present embodiment is attached to an opening of an inner hole. First, the two-system proportioning valve 20 will be described. Since each of the two systems is configured in exactly the same manner inside the housing 21 that is the valve body, only the one system on the left side in the figure will be described here. The same symbol is assigned to the one system on the right side, and the description is omitted.

An inner hole 30 vertically penetrating the housing 21 made of an aluminum alloy, and a cylindrical member 3 fitted and fixed to the opening 36 side of the inner hole 30 via a sealing member 35.
A piston 25 is slidably fitted to the inner peripheral wall surface of each of the four via sealing members 31 and 28, and a liquid chamber 27 is defined on the outer periphery of the piston 25. Housing 21
An inlet 22 that communicates with a master cylinder (not shown), a front-wheel outlet 23 that communicates with a front wheel cylinder, and a rear-wheel outlet 24 that communicates with a rear wheel cylinder are formed. The 23 and the rear wheel side outlet 24 communicate with the liquid chamber 27. A control valve 40 is disposed between the liquid chamber 27 and the rear-wheel-side outlet 24. The control valve 40 includes a poppet valve body 32 urged downward by a valve spring 38 in the figure and a poppet valve body 32. A valve seat forming member 33 which can be attached and detached is provided, and the valve is opened and closed by movement of the piston 25. The piston 25 is urged downward in the drawing by the spring force of a spring 26 stretched in the liquid chamber 27, whereby the control valve 40 is opened. Further, the valve closes when the hydraulic pressure in the liquid chamber 27 reaches a predetermined pressure and the piston 25 moves upward against the spring force of the spring 26, thereby closing the brake hydraulic pressure supplied to the rear wheel side. Is decompressed.

A cap 41 attached to the opening 36 of the inner hole covers the opening 36 to shut off the space between the inner hole 30 and the outside air, and forms an air chamber 29 on the opening 36 side of the piston 25. The air chamber 29 has a sufficient volume that does not affect the movement of the piston 25. Next, the cap 41 according to the present invention will be described.

The cap 41 according to the present embodiment is formed by pressing a stainless steel thin plate integrally into a bottomed cylindrical body, and the outer diameter of the lid 41B, which is the bottom, is substantially equal to the inner diameter of the opening 36. They have the same size. The outer peripheral surface of the cylindrical portion 41A, which is the side wall of the bottomed cylindrical body, is pressed into the inner wall surface of the inner hole 30 as a press-fit portion. Further, the entire surface of the cap 41 including the cylindrical portion 41A and the lid portion 41B is coated with a fluororesin, and a uniform film having a thickness of about 10 μm is formed. That is, the cap 41
Is formed by forming a fluororesin coating on the surface of a substrate made of stainless steel. The cap 41 is attached to the opening 36 by press fitting.

Therefore, according to the present embodiment, the coating made of the fluororesin is softer than the stainless steel and the aluminum alloy, has a small frictional resistance, and is difficult to be easily peeled off, so that the outer peripheral surface of the cylindrical portion 41A comes into contact. Inner hole 30
The cap 41 can be press-fitted without damaging the inner peripheral wall surface of the (opening 36). Moreover, since the cap 41 is formed of a single member, the work of attaching the cap 41 to the opening 36 becomes easy, and the sealing force equivalent to the conventional one is secured by the action of the coating of the press-fitted cylindrical portion 41A. be able to. That is, it is possible to perform an operation as a dust seal that blocks the outside of the apparatus and the inside of the inner hole 30.

Further, since the fluorocarbon resin is coated on the entire surface of the cap 41, even if the caps 41 collide with each other, it is possible to prevent the caps 41 from being damaged. When the proportioning valve 20 is attached to the vehicle or when the brake fluid is replenished, even if the brake fluid adheres to the cap 41, the base material of the cap (stainless steel) due to the chemical resistance of the fluororesin. However, there is no adverse effect such as a change in composition. Here, the brake fluid is a non-mineral oil-based hydraulic fluid containing polyglycol as a main component.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the coating is formed of a fluororesin. However, the present invention is not limited to this, and the same effect can be obtained by coating a material such as zinc plating by electrolysis or molybdenum disulfide. Can be. That is, any material that is softer than the material of the cylindrical portion 41A and the material of the peripheral wall of the inner hole 30 may be used. Also, housing 2
Although the first material has been described as an aluminum alloy and the material of the base material of the cap 41 has been described as stainless steel, other materials may of course be used.

In the above embodiment, the cylindrical portion 41A
The coating was formed not only on the outer peripheral surface of the cap 41 but also on the entire surface of the cap 41, but at least the cylindrical portion 41 pressed against the peripheral wall of the inner hole.
If a film is formed on the outer peripheral surface of A, the same effect as described above can be obtained. Further, the cap 41 has a shape in which the lid 41B is positioned on the inner side of the inner hole with respect to the cylindrical portion 41A, but may have a shape in which the lid is positioned at the opening of the inner hole or outside.

Further, in the above embodiment, an example in which the cap of the present invention is applied to the dual-system proportioning valve 20 has been described. However, the present invention is not limited to this. The present invention is also applicable to a control valve device provided with a valve for controlling a pressure or a flow supplied from an inlet side to an outlet side provided in the housing and opened and closed according to the movement of a piston inserted into the housing.
For example, it can be used for a blind plug of a valve device which is arranged in a clutch operating device and controls the return speed of a piston in a half-clutch region with a flow rate of a hydraulic fluid (similar to the above-mentioned brake hydraulic fluid). The present invention is also applicable to air brake parts and other devices which need to be attached to the opening of the inner hole to prevent foreign substances from entering the inside.

[0020]

As described above, according to the cap of the present invention, the outer peripheral surface of the cylindrical portion of the cap which is in pressure contact with the peripheral wall of the inner hole has a coating softer than the material of the cylindrical portion and the material of the peripheral wall of the inner hole. By forming, it is possible to prevent the generation of chips due to damage to the inner hole at the time of press-fitting the cap,
Since the cap is composed of a single component, the number of components is reduced, and the work of attaching the cap to the opening becomes easy. In addition, the same sealing force as that of the related art can be secured by the press-fitting action, and the action as the dust seal can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a two-system proportioning valve to which a cap according to an embodiment of the present invention is applied.

FIG. 2 is a partially enlarged sectional view showing a conventional cap.

[Explanation of symbols]

 21 Housing 25 Piston 29 Air chamber 30 Inner hole 36 Opening 40 Control valve 41 Cap 41A Tubular part 41B Lid

Claims (5)

[Claims] 1. A cap that has a lid that covers an opening of an inner hole formed in a housing, and a tubular portion that fits into the inner hole, and that shuts off between the inner hole and outside air. The lid and the tubular portion are integrally formed with a single member, and the tubular portion is a press-fit portion for the inner hole,
A cap, wherein a coating softer than a material of the cylindrical portion and a material of the peripheral wall is formed on at least an outer peripheral surface of the cylindrical portion that is in pressure contact with a peripheral wall of the inner hole. 2. The cap according to claim 1, wherein the coating has resistance to a non-mineral oil-based hydraulic fluid containing polyglycol as a main component. 3. The cap according to claim 1, wherein the coating is formed by a fluororesin coating. 4. The valve body as a housing, wherein the housing is opened and closed in response to the movement of a piston slidably inserted through a sealing member in the inner hole, and an outlet is provided from an inlet side provided in the valve body. The cap according to any one of claims 1 to 3, wherein the cap is applied to a control valve device provided with a valve for controlling a pressure or a flow supplied to the side. 5. The control valve device is supplied with a hydraulic pressure from a master cylinder that generates a hydraulic pressure in response to an input operation. When the hydraulic pressure exceeds a predetermined pressure, the pressure is reduced and output to the brake device side. The cap according to claim 4, which has a function and is applied to a proportioning valve, wherein an air chamber is formed on the opening side of the piston.