JP3498554B2 - Sealing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device fitted and fixed to the inside of a tubular member by an end portion of the tubular member that is bent inward, and reliably seals the sealing device and the tubular member. Technology.

[0002]

2. Description of the Related Art As a conventional sealing device of this type, for example, there is a reciprocating sealing device 100 provided in a shaft sealing portion of a gas filled hydraulic shock absorber 200 shown in FIG.

The hydraulic shock absorber 200 includes a rod 201 that reciprocates in an inner cylinder 203, a piston 202 provided on the rod 201, and a sealing fluid L200 above and below the piston 202, and a valve portion 202a is provided on the piston 202. By doing so, a damping force is generated in the reciprocating stroke of the rod 201.

An outer cylinder 204 which constitutes a reservoir chamber 207 is disposed outside the inner cylinder 203, and the gas G200 and a part of the sealing fluid L200 are enclosed in the reservoir chamber 207. A communication path 208 connecting the reservoir chamber 207 and the piston lower chamber 206 is provided at the lower end of the.

Reference numeral 102 denotes a rod guide, which is a communication passage 10 for returning the sealed fluid L200 and the gas G200 flowing out from the piston upper chamber 205 through the clearance 209 between the rod 201 and the rod guide 102 to the reservoir chamber 207.
3 is provided.

On the other hand, the sealing device 100 is mounted on the above-mentioned hydraulic shock absorber 200, is provided with a seal portion 101 for sealing the sliding surface of the rod 201, and is caulked to the inner peripheral surface of the upper end portion of the outer cylinder 204. Has been done.

[0007]

FIG. 5 (a) is an enlarged cross-sectional view of a main part for explaining the sealing device 100. This sealing device 100 includes a main lip 101a, a dust lip 101b, and a rod guide 1 which are made of a rubber-like elastic material on the inner diameter.
A seal portion 101 having a lip 101c that abuts with 02 and functions as a check valve is provided.

Reference numeral 100a is a metal ring, and an annular fitting lip portion 100b made of the same rubber-like elastic body as the lip portion fitted to the inner diameter side of the outer cylinder 204 is provided at the end of the metal ring 100a. It is provided so as to project outward from the portion 100c.

FIG. 5B is a view for explaining a caulking process performed when fixing the sealing device 100 to the shaft sealing portion of the hydraulic shock absorber 200.

In the caulking process, the sealing device 100 is attached to the outer cylinder 20.
After being assembled inside 4, the end portion 204a of the outer cylinder 204 is pressed against the caulking jig (not shown) while relatively rotating, and is bent in the direction of arrow A101. Then, an axial compressive force (arrow A102) is applied to the metal ring 100a to seal and fix it.

However, when the caulking process is performed, the sealing device 100 may move, or the opposite side of the sealing device 100 with which the caulking jig abuts may temporarily tilt up and return to its original position. There is.

This is considered to be a problem in the working method of the caulking process, but as in the sealing device 100 of FIG. 5A, the lip portion 100 is fitted to the outer peripheral end surface of the end portion 100c.
When there is a thin rubber surrounding portion 100d following b,
This rubber-surrounding portion 100d may be moved or compressed during the crimping process, resulting in damage.

Further, in the state of being inserted in the outer cylinder 204, stress concentration (particularly, the area P101 in FIG. 5B) is concentrated on the ring corner portion 100e of the fitting lip portion 100b (the waist portion of the fitting lip portion 100b). Occurs and the corner portion 100e is damaged,
There is also a problem that the sealing performance of the fitting lip portion 100b is deteriorated.

FIGS. 6A and 6B are views for explaining a method of sealing / fixing the metal ring and the outer cylinder 204 of the hydraulic shock absorber 200 according to another structure.

The outer peripheral end surface of the metal ring 150a of the sealing device 150 is not provided with a fitting portion made of a rubber-like elastic body or a thin rubber surrounding portion. An annular lip 150b is formed at a portion slightly inside from the outer circumference of the upper end surface of the metal ring 150a on the anti-sealing side.
Is provided, and as shown in FIG.
The end portion 204a is pressed against the annular lip 150b with the end portion 204a bent by the caulking process to perform sealing.

However, the annular lip 150b and the outer cylinder 204
Since the pressure contact of the end portion 204a of the outer cylinder 204 is performed by a caulking process, the variation in the dimension of the outer cylinder 204 (V1 in FIG.
The sealability of the annular lip 150b is unstable due to the influence of the size) and the variation in the crimping process (V2 size in FIG. 6B).

The present invention was made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to prevent the occurrence of problems in the caulking process at the time of assembly and to make the fitting portion An object of the present invention is to provide a sealing device capable of performing stable sealing / fixing.

[0018]

In order to achieve the above object, according to the present invention, a reinforcing ring fitted inside a tubular member and an inner diameter portion of the reinforcing ring are provided. A seal portion that is in sliding contact with a shaft that is inserted into the outer peripheral surface of the reinforcing ring, and the outer peripheral end surface of the reinforcing ring that extends outwardly from the sealing portion and is in contact with the inner peripheral surface of the tubular member. A mating seal portion for sealing a gap between the reinforcing ring and the tubular member,
In a sealing device in which an end of a tubular member bent inward is fixed to the tubular member by being pressed against an anti-sealing side of a reinforcing ring, a chamfered portion is provided at a corner of the outer peripheral end face of the reinforcing ring on the sealing side. And the outer edge of the joint surface of the fitting seal portion with the reinforcing ring is positioned at the chamfered portion of the reinforcing ring.

According to this structure, there is no fitting seal portion on the outer peripheral end surface of the reinforcing ring, and the outer peripheral end surface of the reinforcing ring and the inner surface of the cylindrical member in the state where the sealing device is fitted to the cylindrical member. Even if the relative movement with the peripheral surface occurs, the fitting seal portion is not damaged.

Since a groove groove is formed between the chamfered portion outside the outer edge of the joint surface of the fitting seal portion with the reinforcing ring and the outer peripheral end surface of the reinforcing ring, the groove groove is formed. No stress is applied to the fitting seal portion from the portion, and the fitting seal portion is gently bent and deformed. Therefore, the stress applied to the fitting seal portion can be relaxed.

It is also preferable that the corner portion on the sealing side of the chamfered portion is rounded.

Thus, it is possible to prevent the flexurally deformed fitting seal portion from being damaged by the corner portion on the sealing side of the chamfered portion of the reinforcing ring.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments.

(Embodiment 1) FIG. 1 is a cross sectional structural explanatory view for explaining an embodiment of a sealing device 1 to which the present invention is applied. Similar to the sealing device described in the section of the prior art, the sealing device 1 is fixed to, for example, a shaft sealing portion of a gas filled hydraulic shock absorber, and oil as a sealing fluid sealed inside the hydraulic shock absorber or The gas is hermetically sealed so as not to leak from the gap on the surface of the rod as the reciprocating shaft.

The structure of the hydraulic shock absorber can be the same as that of the hydraulic shock absorber 200 shown in FIG. 4. For the outline thereof, refer to FIG. 4 and the description of the prior art. Can be grasped.

The sealing device 1 serves as a check valve by abutting the main lip 3 made of a rubber-like elastic body, the dust lip 4, and a rod guide (not shown) on the inner diameter of a flat washer-shaped metal ring 2 as a reinforcing ring. It is provided with a seal S having a functioning lip 5. The main lip 3 provides an appropriate pressure distribution when abutting on the surface of a rod (not shown),
It is urged inward by the spring ring 6.

A chamfered portion 2b having an inwardly rounded R-shaped cross section is provided at a corner of the outer peripheral end surface 2a of the metal ring 2 on the sealing side M. Further, the corner portion 2c of the chamfered portion 2b on the sealing side M has a rounded shape (having a rounded outside).

On the sealing side M of the outer diameter portion of the metal ring 2, an annular fitting seal portion 7 made of the same rubber-like elastic body as the seal portion S is integrally provided. Fitting seal part 7
Protrudes outward from the outer peripheral end surface 2a of the metal ring 2 and abuts on the inner peripheral surface of a cylindrical member (not shown, such as the outer cylinder 204 in FIG. 4) to seal the gap between the metal ring 2 and the cylindrical member. It can be stopped.

The outer edge 7a of the joint surface of the fitting seal portion 7 with the metal ring 2 is located at the chamfered portion 2b, and rubber around the outer diameter side (upper side in the figure) of the edge 7a. It has not been done.

FIG. 2 is a view for explaining a caulking process performed when fixing the sealing device 1 to the shaft sealing portion of the hydraulic shock absorber. In the figure, 204 is an outer cylinder, and 204 a is an end portion of the outer cylinder 204.

The caulking process is the same as the process described in the prior art, but since no rubber around the outer peripheral end face 2a is generated, the sealing device 1 moves or the caulking jig of the sealing device 1 abuts. Even if a phenomenon occurs such that the opposite side temporarily rises so as to incline or returns to the original position, no damage around the rubber or the fitting seal portion 7 occurs.

Further, the outer edge 7a of the fitting seal portion 7
Since the groove groove 8 is formed between the chamfered portion 2b on the outer side and the outer peripheral end surface 2a, no stress is applied to the fitting seal portion 7 from the portion of the groove groove 8 and the fitting seal portion 7 is formed.
Since the fitting seal portion 7 is flexibly deformed from the contact portion 7b, the stress applied to the fitting seal portion 7 is relieved.

In particular, it is possible to prevent stress from concentrating on the outer edge 7a, so that problems such as peeling and cracking from the outer edge 7a can be reduced, so that reliability and durability can be improved. it can.

The corner portion 2c of the chamfered portion 2b having the rounded shape on the sealing side M is flexibly deformed, and the fitting seal portion 7 is formed.
It prevents the occurrence of cracks and peeling inside the.

3 (a) and 3 (b) are views showing a state in which the sealing device 1 is sandwiched and fixed between the upper end surfaces of the rod guides 102A, 102B and the end portion 204a of the outer cylinder 204. .

In FIG. 3A, the rod guide 102
The inclined portion 102Aa provided at the upper end of the outer periphery of A and the back surface of the fitting seal portion 7 are in contact with each other, and the tightening force of the fitting seal portion 7 can be improved. 103 is a communication passage for returning the sealed fluid.

Further, it can be applied to a shape as shown in FIG. 3 (b) in which the communication passage is the groove 102Ba provided on the upper end surface of the rod guide 102B.

The chamfered portion 2b may have a cross-sectional shape that is recessed inward as shown in FIG. 1 or may be a C chamfering of about 45 degrees which is generally performed.

[0039]

According to the present invention, the fitting seal portion can be prevented from being damaged by the caulking process at the time of assembly, the assembling property is improved, and the sealing property and reliability of the fitting portion of the sealing device are improved. It is possible to improve quality, durability and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration explanatory diagram of a sealing device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a caulking process of the sealing device.

FIG. 3 is a diagram illustrating a fixed state of the sealing device.

FIG. 4 is a diagram of a conventional gas-filled hydraulic shock absorber.

FIG. 5 is a view of a conventional sealing device.

FIG. 6 is a view of a conventional sealing device.

[Explanation of symbols]

1 Sealing device 2 Metal ring (reinforcing ring) 2a outer peripheral end face 2b Chamfer 2c corner 3 main lip 4 dust lip 5 lips 6 spring rings 7 Fitting seal part 7a outer edge 8 concave groove 200 hydraulic shock absorber M sealed side S seal part

Claims (2)

(57) [Claims] 1. A reinforcing ring fitted inside a tubular member, a seal portion arranged in an inner diameter portion of the reinforcing ring and slidingly contacting a shaft inserted through the tubular member, and an outer portion of the reinforcing ring. A fitting seal portion that projects outward from the outer peripheral end surface of the reinforcing ring on the sealing side of the diameter portion and contacts the inner peripheral surface of the tubular member to seal the gap between the reinforcing ring and the tubular member. In the sealing device in which the end of the tubular member bent inward is fixed to the tubular member by being pressed against the anti-sealing side of the reinforcing ring, a corner of the outer peripheral end surface of the reinforcing ring on the sealing side. A sealing device comprising: a chamfered portion; and an outer edge of a joint surface of the fitting seal portion with the reinforcing ring is positioned at the chamfered portion of the reinforcing ring. 2. The sealing device according to claim 1, wherein a corner portion on the sealing side of the chamfered portion has a rounded shape.