JP2541731Y2 - Check valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve applied to, for example, a reciprocating sealing device having a check valve mechanism used for a shaft seal portion of a hydraulic shock absorber, and more particularly to a check valve provided with a check lip.

[0002]

2. Description of the Related Art As a conventional check valve provided with such a check lip, for example, there is a check valve as shown in FIGS. That is, the check valve is provided integrally with the reciprocating oil seal 100 having the seal lip 105 used for the shaft sealing portion of the rod 103 of the hydraulic shock absorber, and includes the reservoir chamber 101 and the guide member 106. A flexible check lip 108 is provided so as to block a communication path 107 communicating between the seal chamber 102 and the oil seal 100.

The check lip 108 is connected to the communication passage 10
7, the forward end of the lip deforms in the direction away from the guide member 106 as a flow path wall with respect to the forward fluid pressure from the seal chamber 102 side to the reservoir chamber 101 side, thereby allowing the fluid to flow. When the fluid pressure is in the opposite direction from 101 to the seal chamber 102 side, the tip of the lip
The fluid is prevented from flowing by deforming in the direction pressed by the fluid, so that fluid such as oil or gas flows only in one direction.

[0004]

However, in the case of the above-mentioned prior art, since the check lip 108 provided on the oil seal 100 merely contacts the guide member 106, the check lip 108 is placed in the reservoir chamber. At the time of the non-return pressure action in which the pressure in the opposite direction acts from 101, there has often occurred a problem that the check lip 108 is inverted due to a change in fluid pressure or the like.

The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a check valve which can prevent the check lip from being inverted when a check pressure is applied. It is in.

[0006]

According to the present invention, there is provided a reciprocating sealing device for sealing a shaft of a shock absorber.
Guide that is integrated with the
A flexible check lip arranged to block a flow path provided in the storage member , wherein the check lip comprises:
The direction in which the tip of the lip is deformed in the direction away from the flow path wall for forward fluid pressure to allow fluid flow, and the direction in which the lip tip is pressed against the flow path wall for reverse fluid pressure In the check valve, which is deformed to block the flow of fluid, a rib is provided on the check lip on the side on which the forward fluid pressure acts, and the rib contacts the flow path wall when the reverse fluid pressure acts. The deformation of the check lip is regulated by being in contact with the check lip.

[0007]

[0008]

[Action] In the check valve having the above structure, by the ribs positive direction of the fluid pressure of the check lip is provided on the side acting
When the fluid pressure acts in the opposite direction , the ribs
Deformation of the check lip is restricted by contact with the inverted check lip is prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. FIGS. 1 and 2 show a check valve according to an embodiment of the present invention. In this embodiment as well, as in the conventional example, the check valve is provided integrally with an oil seal 1 for sealing a shaft of a hydraulic shock absorber. The case will be described as an example.

The shaft seal of the hydraulic shock absorber is composed of an outer cylinder 2 and an inner cylinder 3 assembled concentrically with each other and a guide member 10 for guiding the rod 4. Is fixed to the step D of the guide member 10, and the outer periphery of the guide member 10 is fitted to the inner periphery of the outer cylinder 2. A space between the outer cylinder 2 and the inner cylinder 3 is a reservoir chamber G filled with a high-pressure gas or the like. The guide member 10 has a seal chamber between the reservoir chamber G, the oil seal 1 and the guide member 10. A communication hole 12 communicating with E is provided. A rod 4 is slidably inserted into the inner periphery of the guide member 10 via a sleeve 11, and a piston upper chamber F and a seal chamber E in the inner cylinder 3 pass through a gap between the rod 4 and the sleeve 11. There is communication between them.

The oil seal 1 includes an annular seal body 5 fitted on the inner periphery of the outer cylinder 2, a rubber-like elastic lip 6 provided on the inner periphery of the seal body 5, and an outer seal 2. A check lip 7 made of a rubber-like elastic body and constituting a check valve provided between the inner periphery of the cylinder 2 and the seal lip 6.

The seal body 5 is provided with an outer cylinder seal portion 51 which protrudes in the axial direction from the outer peripheral portion of a metal reinforcing ring 8 having a rectangular cross section, and is fitted on the inner periphery of the outer cylinder 2. 5
The outer periphery of 1 extends and covers the outer periphery of the reinforcing ring 8.

The seal lip 6 is composed of a main seal lip 61 and a sub seal lip 62. The main seal lip 61 extends from the inner end of the reinforcing ring 8 to the fluid side O to be sealed in the axial direction. The seal lip tip 61a is in slidable sealing contact with the outer periphery of the rod 4. A spring 9 for pressing the rod 4 is mounted on the outer circumference of the main seal lip tip portion 61a. The guide member 10 is provided with a stepped portion C recessed by the space occupied by the main seal lip 61.

The sub-seal lip 62 extends from the inner end of the reinforcing ring 8 to the atmosphere side A and faces inward in the radial direction. The tip 62a of the sub-seal lip slidably contacts the outer periphery of the rod 4. doing. Then, the auxiliary seal lip 62
The outer periphery extends to the vicinity of the outer periphery of the end face on the atmosphere side of the reinforcing ring 8 and covers the reinforcing ring 8. The auxiliary seal lip 62 has a function of preventing intrusion of sand, dust and the like.

On the other hand, the check lip 7 constituting the check valve of the present invention is located on the outer peripheral side of the main seal lip 61 and is inclined so as to gradually expand from the inner peripheral portion of the reinforcing ring 8 toward the fluid O to be sealed. It is growing.

The check lip 7 has a mechanism for flowing oil and gas in only one direction when the rod 4 reciprocates. That is, the piston upper chamber F → the seal chamber E →
The flow from the communication hole 12 to the reservoir chamber G is allowed, and the flow in the reverse direction is prevented. Specifically, the lip tip 7a is deformed in a direction away from the guide member 10 as a flow path wall for the fluid pressure in the forward direction to allow the fluid to flow, and for the fluid pressure in the reverse direction. The lip tip 7a is deformed in the direction pressed by the guide member 10, and blocks the flow of fluid. The portion of the guide member 10 with which the lip tip 7a of the check lip 7 abuts is a step B adjacent to the outside of the step C.

A rib 71 is provided on the inner peripheral surface 7b of the waist on the side of the check lip 7 on which the forward fluid pressure acts. When the fluid pressure acts in the opposite direction, the rib 71 is brought into contact with the guide member 10 to restrict the deformation of the check lip 7.

A plurality of ribs 71 are arranged in the circumferential direction. The longitudinal cross-sectional shape of the ribs 71 is triangular.
Is perpendicular to the rod 4, and the inclined surface 71b in the axial direction is parallel to the rod 4. That is, the apex angle between the radial slope 71a and the axial slope 71b is a right angle.

The outer periphery of the guide member 10 is a fitting surface 10a fitted to the inner periphery of the housing 2, and the air extending radially inward from both ends of the fitting surface 10a toward the atmosphere side A. The slope 10b is formed of a side slope 10b and a reservoir chamber side slope 10c extending radially inward toward the reservoir chamber G. Is up to the outer peripheral edge of the step portion D. The communication hole 12 is formed between the outer peripheral end of the step B and the reservoir chamber side slope 10c.
And penetrate between them.

The air-side end face 10d of the guide member 10
Is the rubber portion 6 between the outer cylinder seal portion 51 and the check lip 7.
3 and the front end portion 51a of the outer cylinder seal portion of the oil seal is engaged with the atmosphere side slope 10b. Further, a seal rubber portion 62 b baked on the atmosphere side end surface of the reinforcing ring 8 is in contact with the inner peripheral surface of the inward flange portion 21 of the outer cylinder 2. The end face 10c of the guide member 10 to which the inner cylinder 3 is fitted is in contact with the upper piston chamber F.

In the oil seal provided with the check valve having the above-described structure, the fluid inserted into the upper piston chamber F at the time of the extension process of the rod 4 causes the fluid between the inner periphery of the sleeve 11 and the outer periphery of the rod 4 to pass through. Then, the fluid flows into the seal chamber E, and the fluid presses the inner peripheral surface 7b of the check lip 7 and the axial inclined surface 71b of the rib 71, so that the radial inclined surface 71a of the rib 71 and the stepped portion B of the rod guide 10 form. When a gap is formed between the check lip 7 and the tip 7a of the check lip 7 is further pressed, the check lip 7 is deformed so as to be turned up and a gap is formed. It flows into room G.

On the other hand, at the time of the contraction step of the rod 4, a check pressure is applied to press the fluid in the chamber G to the outer peripheral surface 7c of the check lip 7 through the communication hole 12 of the rod guide 10. At this time, the lip tip 7a of the check lip 7 and the radial slope 71a of the rib 71 are pressed by the step B of the rod guide 10 to prevent the fluid from flowing back into the chamber E.

At the time of the check pressure, even if an abnormally high pressure acts due to the pressure fluctuation, the rib 71 supports the tip of the check lip 7, so that the lip tip 7a of the check lip 7 moves toward the seal chamber E side. Is prevented from being inverted.

In the above embodiment, the ribs 71 can be changed in width and rigidity in accordance with the use of pressure, and may be provided all around.

Further, in this embodiment, an example in which the check valve is provided integrally with the sealing device for sealing the shaft of the shock absorber has been described. However, the present invention is not limited to the shock absorber and, in short, uses a check lip. Of course, it can be widely used for a check valve for checking a fluid.

[0026]

The present invention has the above configuration and operation, and is provided on a guide member for guiding the rod of the shock absorber.
A rib is provided on the check lip arranged so as to block the flow path provided, and when a fluid pressure in the opposite direction acts , the rib is provided.
Of the check lip by contacting the flow path wall to restrict the deformation of the check lip.
This eliminates the need for proper flow for forward fluid pressure.
The body can circulate, and for the opposite fluid pressure,
Even when a high pressure is applied, the reversal of the check lip can be prevented, and the reliability of the check valve can be improved.

Further, since the amount of deformation of the check lip can be restricted to a predetermined range, the distortion generated in the check lip is reduced, and the durability can be improved. Furthermore, since the check pressure can be increased in this way, when used in a shock absorber, it can be used in a wide pressure range from low pressure to high pressure, and the degree of freedom in designing damping force of the shock absorber is reduced. improves.

Furthermore, since the reversal of the check lip can be prevented, the quality of the shock absorber and the function thereof can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a reciprocating sealing device provided with a check valve according to an embodiment of the present invention in use.

FIG. 2 is a longitudinal sectional view of a main part of the state in which the reciprocating sealing device of FIG. 1 is taken out.

FIG. 3 is a longitudinal sectional view of a main part of a conventional reciprocating sealing device in use.

FIG. 4 is a longitudinal sectional view of a main part of the reciprocating sealing device of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Oil seal 2 Outer cylinder 21 Inward flange part 3 Inner cylinder 4 Rod 5 Seal main body 51 Outer cylinder seal part 51a Outer cylinder seal tip part 6 Seal lip 61 Main seal lip 61a Main seal lip tip part 62 Secondary seal lip 62a Secondary seal Lip tip portion 62b Seal rubber portion 63 Rubber portion 7 Check lip 7a Lip tip 7b Inner peripheral surface 7c Outer peripheral surface 71 Rib 71a Radial slope 71b Axial slope 8 Reinforcement ring 9 Spring 10 Guide member 10a Fitting surface 10b Atmospheric slope 10c Reservoir Room side slope 10d Atmospheric side end face 10e Piston upper chamber side end face 11 Sleeve 12 Communication hole

Claims (1)

(57) [Scope of request for utility model registration] 1. A reciprocating sealing device for sealing a shaft of a shock absorber.
Guide member which is provided physically and guides the rod of the shock absorber
A flexible check lip arranged to block the flow path provided in the lip, and the check lip is deformed in a direction in which the lip tip is separated from the flow path wall with respect to a forward fluid pressure. A check valve that allows the flow of fluid to prevent the flow of fluid by deforming the tip of the lip against the flow path wall against the reverse fluid pressure. A rib provided on a side on which a fluid pressure acts in the direction, and the rib is brought into contact with the flow path wall when the fluid pressure acts in the opposite direction to regulate deformation of the check lip.