JP2597265Y2 - Oil seal structure of hydraulic shock absorber - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal structure in a hydraulic shock absorber in which a piston rod is inserted into an outer tube via an oil seal and a rod guide.

[0002]

2. Description of the Related Art Conventionally, an oil seal structure of a hydraulic shock absorber is disclosed in Japanese Utility Model Laid-Open No. 4-105648. This will be described with reference to FIG. 4. A piston rod 104 is inserted into the outer tube 101 from above via an oil seal 102 and a rod guide 103, and the oil seal 102 is connected to a reinforcing ring support 106 of the rod guide 103. Between the rod guide 1
03 holds the upper end of the damper cylinder 107.

Then, communication paths 108 and 109 forming return channels are formed on the upper surface of the reinforcing ring support portion 105 of the rod guide 103 and the outer peripheral surface of the rod guide 103, respectively.
Hydraulic oil flowing between the rod guide 103 and the oil seal 102 is returned to the reservoir chamber 110 through these communication passages 108 and 109.

The oil seal 102 has a seal member 112 fixed to a flat metal reinforcing ring 111. The seal member 112 has a lip 113, which is in sliding contact with the outer peripheral surface of the piston rod 104 on the inner peripheral side of the reinforcing ring 111. 114, a check lip portion 115 that contacts the step portion 103a of the rod guide 103 on the lower surface, and a rod guide 103 on the outer peripheral portion.
Annular recess 116 between the communication passage 108 and the communication passage 109
The outer peripheral lip portion 117 is formed so that the inner peripheral surface of the outer tube 101 comes into contact with the outer tube 101 with a margin.

[0005]

However, in the above-described oil seal structure, since the outer peripheral lip portion 117 of the oil seal 102 has an interference with the outer tube 101 , the outer tube is not assembled in the assembly process.
When the oil seal 102 is inserted into the inner tube 101 , the outer lip 117 may be caught on the end of the outer tube 101 and may be damaged. Also, the oil seal 102
When the outer peripheral lip 117 is deteriorated due to deterioration over time, the outer peripheral lip 117 may go into the annular concave portion 116 of the rod guide 103 , so that the interference may be lost and the sealing property may be lost.

[0006]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide an oil seal and a rotor in an outer tube.
Hydraulic shock absorber with piston rod inserted through head guide
In the vessel, the oil seal is replaced with a metal reinforcing ring
And a plurality of recesses formed in the outer peripheral portion of the metal reinforcing ring,
Outer tubing is applied to the outer periphery of the metal reinforcing ring including these recesses.
Outer lip and annular ring
And a rule part. The metal reinforcing ring may be a flat plate.
Shaped parts.

[0007]

According to the first aspect, a plurality of concave portions are provided on the outer peripheral portion of the metal reinforcing ring.
Since the seal portion is formed, for example, when the sealing property of the outer peripheral lip portion is reduced, the annular seal portion having a larger volume by the concave portion can be supplemented, and each interference can be dispersed. Thus, the assembling property and the sealing property can be improved. In claim 2, the metal reinforcing ring has a flat plate shape.
As a part, the oil seal can be made thin.
Wear.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a sectional view of a main part of a hydraulic shock absorber to which the oil seal structure according to the present invention is applied, FIG. 2 is an enlarged sectional view of an oil seal of the shock absorber, and FIG. 3 is a plan sectional view of the oil seal. is there.

In FIG . 1, a damper cylinder 2 is erected in an outer tube 1 of a hydraulic shock absorber while an upper end portion thereof is held by a rod guide 3. The piston rod 5 is inserted through the oil seal 4 fitted on the surface and the rod guide 3, and the oil seal 4 is held between the rod guide 3 and the end plate 6.

A bush 7 for slidingly contacting the outer peripheral surface of the piston rod 5 is fitted on the inner peripheral surface of the rod guide 3, and a holding portion 8 for holding the lower surface of the oil seal 4 is formed on the upper portion. A communication groove 9 is formed on the outer peripheral surface of the rod guide 3, and an annular recess 11 is provided between the communication groove 9 and the communication groove 10. A return flow path is provided for returning the hydraulic oil flowing during the period to the reservoir chamber 12.

The oil seal 4 has a sealing member 15 fixed to a flat metal reinforcing ring 14 as shown in FIG.
The seal member 15 has two lip portions 16 and 17 formed on the inner peripheral side of the metal reinforcing ring 14 so as to slidably contact the outer peripheral surface of the piston rod 5 (see FIG. 1).
The outer circumference of the metal ring 14 is provided with fastening rings 18 and 19, and the check lip portion 20 on the lower surface of the metal reinforcing ring 14 is in contact with the step 3a ( see FIG. 1) of the rod guide 3 (see FIG. 1) .
Is formed.

Further, the annular recess 11 of the rod guide 3 is provided on the outer periphery of the metal reinforcing ring 14 of the oil seal 4 (see FIG. 1).
The outer tube 1 (see FIG. 1) is formed to have an outer peripheral lip 21 to be brought into contact with the inner peripheral surface with a margin, and to be brought into contact with the inner peripheral surface of the outer tube 1 with a margin. An annular seal portion 22 is formed. Here, as shown in FIG. 3, a plurality of recesses 24 are formed in the outer peripheral portion of the metal reinforcing ring 14 so as to compensate for the insufficient volume of the annular seal portion 22.

With the above configuration, the outer peripheral lip portion 21 and the annular seal portion 22 of the oil seal 4 shown in FIG.
Because the inner tube side of the outer tube 1 (see FIG. 1) is sealed by the outer lip portion 21 and the annular seal portion 2
2 can be dispersed to such an extent that the sealing performance is not impaired, so that the assembling property is improved and the outer peripheral lip 2
Even in the case where the sealing property of (1) is reduced, the sealing property can be maintained by the annular seal portion 22.

[0014]

As described above, according to the first aspect of the present invention,
The oil seal structure of the shock absorber is
Since the number of recesses is formed, for example, when the sealing performance of the outer peripheral lip portion is reduced , the volume is increased by the recesses.
In addition to the supplementary annular seal portion, the interference can be dispersed and the assembling property and the sealing property can be improved. Oy of the hydraulic shock absorber according to claim 2.
Since the metal seal ring is a flat plate-shaped part,
The oil seal can be formed thin.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a hydraulic shock absorber to which an oil seal structure according to the present invention is applied.

FIG. 2 is an enlarged sectional view of an oil seal of the shock absorber.

FIG. 3 is a cross-sectional plan view of the oil seal.

FIG. 4 is a sectional view of a main part of a hydraulic shock absorber to which a conventional oil seal structure is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer tube, 2 ... Damper cylinder, 3 ... Rod guide, 4 ... Oil seal, 5 ... Piston rod, 11
... an annular concave part forming a part of the return flow path, 14 ... a metal reinforcing ring,
15 seal member, 21 outer peripheral lip portion, 22 annular seal portion, 24 concave portion of metal reinforcing ring.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yutaka Sato 1-14-1, Fujiwara-cho, Gyoda-shi, Saitama Prefecture Showa Manufacturing Co., Ltd. Saitama Head Office Factory (72) Inventor Tsuneo Mochizuki 3-30 Horikiri, Katsushika-ku, Tokyo No. 1 Inside Arai Seisakusho Co., Ltd. (56) References JP-A-55-103130 (JP, A) JP-A-4-105648 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16F 9/00-9/58

Claims (2)

(57) [Scope of request for utility model registration] 1. A hydraulic shock absorber in which a piston rod is inserted into an outer tube via an oil seal and a rod guide, wherein the oil seal is a metal auxiliary serving as a base.
A strong ring and a plurality of recesses formed on the outer periphery of the metal reinforcing ring
And the outer periphery of the metal reinforcing ring including these recesses.
Outer lip formed to be inscribed in the tube
And an annular seal portion . 2. The oil seal structure of a hydraulic shock absorber according to claim 1, wherein said metal reinforcing ring is a flat part .