JP2004019866A - Reciprocating seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating seal which can be quickly and inexpensively incorporated while securing sealability. <P>SOLUTION: The reciprocating seal is provided with a main seal having a first metallic ring 14 with a hole in which a gap inbetween a reciprocating shaft is less than a prescribed amount and a main seal lip 11 fixed to the first metallic ring 14 and sealingly brought into contact with the outer peripheral face of the shaft, and a dust seal having a second metallic ring 15 adjacent to the face on the atmosphere side of the first metallic ring and a dust seal lip 16 fixed to the second metallic ring 15 and sealingly brought into contact with the outer peripheral face of the shaft. The dust seal is fixed to the main seal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reciprocating seal used for a shaft sealing portion or the like of various devices that perform relative reciprocating movement such as a shock absorber of an automobile.
[0002]
[Prior art]
As a conventional reciprocating seal of this type, there is a reciprocating seal 100 provided in a shaft sealing portion of a shock absorber 200 shown in FIG.
[0003]
The shock absorber 200 includes a rod 201 that reciprocates in an inner cylinder 203, a piston 202 provided in the rod 201, a sealed fluid L200 above and below the piston 202, and an outer cylinder 204 disposed outside the inner cylinder 203. I have.
[0004]
At the lower end of the inner cylinder 203, a communication path 208 connecting the reservoir chamber 207 and the lower piston chamber 206 is provided.
[0005]
A communication passage 103 is provided for returning the sealed fluid L200 flowing out of the upper piston chamber 205 through the clearance 209 between the rod 201 and the rod guide 102 to the reservoir chamber 207.
[0006]
The shock absorber 200 generates a damping force in the reciprocating process of the rod 201 by providing the piston 202 with the valve portion 202a.
[0007]
Further, in a state where the shock absorber 200 having such a configuration is acting, the piston 202 reciprocates up and down, so that a pressure fluctuation occurs in the sealed fluid existing in the piston upper chamber 205 and the piston lower chamber 206. The communication passage 103 absorbs this pressure fluctuation and prevents the shock absorber 200 from being damaged.
[0008]
The reciprocating seal 100 is mounted on the shock absorber 200 as described above. The reciprocating seal 100 is fixed to the housing 204 and seals the sliding surface of the rod 201 with the main seal lip 101 and dust from the outside such as dust and foreign matter. And a dust seal lip 106 for preventing intrusion.
[0009]
FIG. 4 is an enlarged view of the configuration of the reciprocating seal 100 for reciprocating motion in more detail.
[0010]
The reciprocating seal 100 includes metal rings 104 and 105. The main seal lip 101 is fixed to the metal ring 104 to form a main seal with the metal ring 104 and the main seal lip 101. The dust seal lip 106 is fixed to the metal ring 105. The metal ring 105 and the dust seal lip 106 constitute a dust seal, and the main seal and the dust seal are combined to constitute the reciprocating seal 100.
[0011]
The main seal lip 101 faces the flow passage 107 to which the pressure of the sealed fluid L200 is applied through a clearance 209 between the rod 201 and the rod guide 102 from the upper piston chamber 205.
[0012]
Then, under the above-described pressure fluctuation, a high-pressure hydraulic pressure of a maximum of 9 MPa acts on the main lip 101. Therefore, it is necessary to improve the sealing performance, and the metal ring 104 for fixing the seal lip 101 is brought as close as possible to the rod 201 to increase the rigidity of the main lip.
[0013]
FIG. 5 shows a reciprocating seal conventionally applied to a shock absorber or the like. In this reciprocating seal, the inner diameter of the metal ring 104 is made larger than the outer diameter of the rod 201, for example, a main seal. Rubber was injected into the mold from the lip side to form the main seal lip 101 and the dust seal lip 106 continuously.
[0014]
However, in a use environment in which a high pressure of 9 MPa is applied to the main seal lip 101 as described above, the rigidity of the main seal lip is low in the reciprocating seal shown in FIG. It was difficult.
[0015]
Therefore, in order to increase the rigidity of the main seal lip and ensure sufficient sealing performance, it is necessary to increase the rigidity of the main seal lip by bringing the inner diameter of the metal ring 104 as close as possible to the outer diameter of the rod 201, When a metal ring having a small inner diameter is used, it is difficult to apply a molding method for continuously and integrally forming a main seal lip and a dust seal lip, which has been conventionally used in the reciprocating seal shown in FIG. .
[0016]
It is also possible to use only one metal ring and fix the main seal lip on the surface on the sealing side of the metal ring and the dust seal lip on the surface on the atmosphere side. Unless molding is possible, molding with a single mold requires two rubber inlets, which complicates the mold configuration and increases molding costs.
[0017]
Further, it is possible to fix the dust seal lip with another mold after first fixing the main seal lip to one metal ring, for example, but the molding is troublesome and the molding cost is similarly increased.
[0018]
For this reason, as shown in FIG. 4, the main seal and the dust seal are separated from each other, and are separately incorporated when incorporated in a shock absorber or the like, so that a reciprocating seal that can ensure sufficient sealing performance at low cost is provided. Had formed.
[0019]
[Problems to be solved by the invention]
However, in the case of the above-described conventional technology, the following problem has occurred.
[0020]
Compared with the conventional reciprocating seal in which the main seal lip and the dust seal lip are integrated, two separate seals must be incorporated in the process of producing the shock absorber, reducing production efficiency and increasing production cost. Was.
[0021]
In addition, when assembling into a shock absorber, it is necessary to center the main seal and dust seal in order to ensure the sealing performance, so it must be carefully incorporated, and quality control in the production process is required This increased costs.
[0022]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a reciprocating seal that can be assembled quickly and inexpensively while ensuring sealing performance.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, a reciprocating seal according to the present invention seals an annular gap between a housing and a shaft, and has a hole in which a gap between the outer peripheral surface of the shaft and the shaft is smaller than a predetermined amount. A main seal having a first metal ring, a main seal lip secured to the first metal ring and sealingly contacting the outer peripheral surface of the shaft; and a main seal adjacent to an atmosphere-side surface of the first metal ring. And a dust seal having a dust seal lip fixed to the second metal ring and sealingly contacting the outer peripheral surface of the shaft, wherein the dust seal is fixed to the main seal. It is characterized by having.
[0024]
Here, when the gap between the outer peripheral surface of the shaft and the hole of the first metal ring of the main seal is smaller than a predetermined value, the main seal lip and the dust seal lip are continuously and integrally formed on one metal ring. Is usually a difficult gap.
[0025]
In the reciprocating seal according to the present invention, since the dust seal is fixed to the main seal, it can be easily and quickly incorporated into a shock absorber or the like, thereby increasing production efficiency.
[0026]
Further, the second metal ring has an annular portion, and a bent portion obtained by bending an outer peripheral portion of the annular portion substantially perpendicularly to the annular portion. It is preferable that the dust seal is fixed to the main seal by fitting with a metal ring.
[0027]
With this configuration, the dust seal can be easily fixed to the main seal, and concentricity of both seal lips can be ensured.
[0028]
In addition, the first metal ring has a projection on a surface facing the second metal ring, the second metal ring has a hole, and the second metal ring has a hole. It is preferable that the dust seal is fixed to the main seal by inserting the convex portion of the first metal ring and crushing the convex portion.
[0029]
With such a configuration, regardless of the plate thickness of the two metal rings, they can be surely integrated, and the positioning of the two seal lips can be easily performed. Even when the convex portion is crushed, the two metal rings do not move relative to each other, so that they can be accurately integrated.
[0030]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto unless otherwise specified. Absent.
[0031]
A reciprocating seal according to an embodiment of the present invention will be described with reference to FIG. The reciprocating seal according to this embodiment is applied to a shaft sealing portion of a shock absorber of an automobile in the prior art described with reference to FIG. 3, and is a housing as two members provided coaxially and relatively reciprocating. This seals an annular clearance between the shaft 204 and the shaft 201 inserted into the housing.
[0032]
The configuration and operation of the shock absorber refer to the description in the section of the related art, and the description is omitted here. In the description, when it is necessary to describe the configuration of the shock absorber, the same reference numeral is attached and the description is replaced.
[0033]
(First Embodiment)
The reciprocating seal 1 of the shock absorber shown in FIG. 1 includes a main seal and a dust seal. The main seal includes a circular metal ring 14 having a hollow hole formed by pressing a metal plate material by press working or the like. The main seal lip 11 has an elastic member such as rubber fixed to the metal ring 14 by baking or bonding.
[0034]
The main seal lip 11 contacts the outer peripheral surface of the shaft to prevent leakage of the fluid sealed on the side to be sealed. As described above, the main seal lip 11 has a high pressure of about 9 MPa at the maximum. Since high pressure is required due to the action of hydraulic pressure, it is necessary to increase the rigidity of the seal lip. For this reason, the diameter of the hollow hole of the metal ring 14 to which the seal lip is fixed is made as small as possible and slightly larger (0.5 mm to 3 mm) than the outer diameter of the shaft 201. Further, a spring 17 is provided on the back surface of the main seal lip 11 so that the main seal lip maintains a tightening force in contact with the shaft outer peripheral surface.
[0035]
The dust seal also has a hollow hole formed by pressing a metal plate material by press working or the like, and the annular portion 15b and the outer peripheral portion of the annular portion are substantially perpendicular to the annular portion. It comprises a metal ring 15 having a bent portion 15a and a dust seal lip 16 in which an elastic member such as rubber is fixed to the metal ring 15 by baking or bonding.
[0036]
The dust seal lip 16 prevents intrusion of dust such as dust and foreign matters from the outside to the side to be sealed.
[0037]
Then, as shown in FIG. 1, by fitting a surface of the metal ring 15 facing the axis of the outer peripheral portion 15 a with a surface 14 a of the metal ring 14 facing the inner peripheral surface of the housing 204, the dust seal is replaced with the main seal. , And the two parts of the dust seal and the main seal are integrated into one part to form the reciprocating seal 1.
[0038]
For fitting and fixing, first, the metal ring 15 is formed into a substantially L-shaped cross section as shown in FIG. 1 and a bent portion 15a is formed, and an inner peripheral surface of the metal ring 14 is formed on an inner peripheral surface of the bent portion 15a. 14a can be fixed by press-fitting and fitting.
[0039]
Further, the metal ring 15 is set to a circular shape having no bent portion 15a, and after setting the main seal and the dust seal in an overlapping manner, a load is applied only to the outer peripheral portion of the metal ring 15 and the metal ring 15 is bent substantially vertically to thereby form the metal ring of the main seal. 14 can be brought into contact with and fixed to the outer peripheral side surface 14a.
[0040]
In this way, by fixing the dust seal to the main seal and integrating the main seal and the dust seal to form the reciprocating seal 1, the main seal can be used in the production process of a shock absorber or the like as a conventional separate body. And two dust seals have to be incorporated, which can reduce the production efficiency, which can be improved, and can be incorporated quickly, so that the production efficiency can be increased and the production cost can be reduced.
[0041]
Also, in the production process, if the main seal lip and the dust seal lip are not assembled while aligning the center with the shaft in the production process, the sealing function will be reduced, and quality control is required. When the dust seal is fitted, if the concentricity with the main seal is secured as in the form of the above, the sealing performance can be maintained without having to manage whether or not the concentricity is secured when incorporating it into the shock absorber. Can be secured.
[0042]
In the reciprocating seal according to the present embodiment, the outermost peripheral surface of the metal ring of the dust seal and the outermost peripheral surface of the metal ring of the main seal are substantially the same, and the inner wall surface of the housing 204 to which the reciprocating seal is fixed. And a notch corresponding to the thickness of the bent portion 15a of the dust seal is provided on the outer circumferential surface of the metal ring 14 of the main seal so that the outer circumferential surfaces of the two seals are close to each other. If it fits in the annular gap of the shaft, the shape is not particularly limited. If the outer peripheral side surface of the metal ring 14 of the main seal fits into the bent portion 15a of the metal ring 15 and the main seal does not fall off from the dust seal, the shape of the main seal may be reduced. It is not necessary to provide notches in the metal ring.
[0043]
(Second embodiment)
In the first embodiment, the bent portion 15a of the metal ring 15 of the dust seal and the outer peripheral side surface 14a of the metal ring 14 of the main seal are fitted together to fix and integrate the dust seal with the main seal. In the embodiment, as shown in FIG. 2, the metal ring 14 of the main seal is provided with three convex portions 14d so as to be equally divided into three in the circumferential direction, the metal ring 15 of the dust seal is provided with a hole, and the metal ring of the main seal is formed. The projection 14d of the ring 14 is inserted into the hole of the metal ring of the dust seal, and then the projection 14d is crushed to fix the dust seal to the main seal.
[0044]
In the configuration in which the outer peripheral side surface of the first metal ring and the bent portion of the second metal ring are fitted and fixed as in the first embodiment, the main seal is fixed once so that the main seal does not fall off the dust seal. Since the contact area and contact pressure of the two metal rings are necessary, it is difficult to fix them accurately when the thickness of the metal ring of the main seal is small, or it is difficult to handle. However, according to the present embodiment, it is possible to securely fix and to easily handle.
[0045]
In addition, if the number of protrusions provided on the metal ring of the main seal is three, both seals can be accurately positioned before being crushed, and since both seals do not move relative to each other when crushing, Accurate concentricity can be ensured.
[0046]
Depending on the jig or the like used for crushing, as long as accurate concentricity can be ensured, the number of the protrusions is not limited to three, and may be one or more than three. Further, the position of the convex portion is not limited to the position shown in the figure, but can be changed according to the shape of the housing or the like.
[0047]
Furthermore, in the present embodiment, the convex portion is provided on the metal ring of the main seal and the hole is provided on the metal ring of the dust seal, but the convex portion may be provided on the metal ring of the dust seal and the hole may be provided on the metal ring of the main seal. Similar effects can be obtained.
[0048]
【The invention's effect】
As described above, according to the present invention, the main seal and the dust seal are originally composed of two parts, but the dust seal is fixed to the main seal and integrated, so that the reciprocating seal can be quickly manufactured while maintaining the sealing performance. Can be incorporated into Therefore, the production efficiency of the product to which the reciprocating seal is applied can be increased, and the cost in the production process can be reduced.
[Brief description of the drawings]
FIG. 1 is a half sectional view of a reciprocating seal according to a first embodiment.
FIG. 2 is a half sectional view of a reciprocating seal according to a second embodiment.
FIG. 3 is a cross-sectional view of a shock absorber to which a reciprocating seal is applied.
FIG. 4 is a half sectional view of a conventional reciprocating seal.
FIG. 5 is a half sectional view of another reciprocating seal according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reciprocating seal 11, 101 Main seal lip 14, 104 Metal ring 15, 105 to which main seal lip is fixed Metal ring 16, 106 to which dust seal lip is fixed Dust seal lip 17 Spring 102 Rod guide 103 Communication path 107 Flow path

Claims (3)

It seals the annular gap between the housing and the shaft,
A main seal having a first metal ring having a hole with a gap smaller than a predetermined amount from the outer peripheral surface of the shaft, and a main seal lip fixed to the first metal ring and in sealing contact with the outer peripheral surface of the shaft; ,
A dust seal having a second metal ring adjacent to an atmosphere-side surface of the first metal ring, and a dust seal lip fixed to the second metal ring and in sealing contact with the outer peripheral surface of the shaft. For reciprocating seals,
A reciprocating seal, wherein the dust seal is fixed to the main seal. The second metal ring has an annular portion, and a bent portion obtained by bending an outer peripheral portion of the annular portion substantially perpendicularly to the annular portion,
The reciprocating seal according to claim 1, wherein the dust seal is fixed to the main seal by fitting the bent portion and the first metal ring. Having a convex portion on a surface of the first metal ring facing the second metal ring,
The second metal ring has a hole,
2. The dust seal is fixed to the main seal by inserting a convex portion of the first metal ring into a hole of the second metal ring and then crushing the convex portion. Reciprocating seal.

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