JP2005308204A - Oil seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil seal which is used in a front fork suspension of a two-wheeled vehicle and can be mounted in a narrow space and simplify the mounting work even when ingress of foreign matters such as muddy water and dust can be especially prevented during the traveling. <P>SOLUTION: A plurality of dust seal lips 25, 26 which are integrated with an oil seal lip 23 with tip parts directed to the atmosphere side A are provided on an oil seal 1 to seal an annular space formed by a housing and a shaft which are concentrically assembled, and an end face 18 of a second cylindrical part 13 extending from a return part 12 provided on a core 10 is pressed against a side end face 4 of a projecting part 3 formed on the housing 2 to fix the oil seal 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oil seal used in relation to a two-wheel front fork suspension and used in other general industrial fields.

  The oil seal for the two-wheel front fork suspension that is installed to seal the annular space formed by the relatively movable and concentrically assembled housing and shaft is used in places where the external use conditions are severe. In particular, it is necessary to prevent the entry of foreign matter such as muddy water and dust during traveling. For this reason, in addition to the oil seal, a dust seal is mounted on the atmosphere side. Patent Document 1 below also discloses an invention in which an oil seal and a dust seal are mounted.

  FIG. 7 shows a state where an oil seal 101 and a dust seal 102 used for a conventional two-wheel front fork suspension are attached. The oil seal 101 includes a first cylindrical portion 111 that is fitted to the inner periphery of the housing 103 via a fixed sealing portion 121 and a second cylindrical portion 112 that is U-turned from the atmosphere side A terminal of the first cylindrical portion 111. And a metal core 110 comprising a flange portion 113 extending in the axial inner circumferential direction from the sealed fluid side B terminal of the second cylindrical portion 112, and an inner portion of the flange portion 113 of the metal core 110 formed integrally with the fixed sealing portion 121. It has a seal main body 120 composed of an oil sealing lip 122 that is vulcanized and bonded to the circumferential end and extends to the sealing fluid side B, and a dust prevention lip 123 that extends to the atmosphere side. The dust seal 102 includes a cylindrical core 131 fitted to the inner periphery of the housing 103 via a fixed sealing portion 141 and a flange core 132 extending from the atmosphere side A terminal of the cylindrical portion 131 toward the outer periphery. A second dust seal lip 143 integrally formed with the fixed sealing portion 141 and vulcanized and adhered to the dust core 130 and having a tip portion extending to the atmosphere side, as well as a first dust seal lip 142 extending to the atmosphere side; have.

  In this mounted state, the oil seal 101 mainly seals the object to be sealed, and the dust seal 102 mainly functions to seal foreign matter such as muddy water and dust. Therefore, the oil seal 101 and the dust seal 102 have different functions in the annular space. It is necessary to install the two seals separately, and it is necessary to secure a wide space for mounting the two seals 101 and 102, and the mounting operation becomes complicated. In addition, it is necessary to process the mounting portion in order to fix the seal in the annular space with the seal pressing part (snap ring), and reduction of the work has been desired.

JP 2003-185028 A

  In view of the above, the present invention is used in relation to a two-wheel front fork suspension and is used in a narrow space even when the use conditions during traveling are severe and it is particularly necessary to prevent entry of foreign matter such as muddy water and dust. Another object of the present invention is to provide an oil seal that can be easily mounted.

  In order to achieve the above object, an oil seal according to claim 1 of the present invention is an oil seal installed in an annular gap between two members assembled so as to be relatively movable with each other, and is fitted to one member. A cored bar, an oil seal lip that is vulcanized and bonded to the cored bar to seal the object to be sealed, and is positioned on the atmosphere side of the oil seal lip with the tip portion facing the atmosphere side. It has a plurality of dust seal lips formed integrally with the oil seal lip which is in sliding contact with the member and seals external dust and the like.

  An oil seal according to a second aspect of the present invention is the oil seal according to the first aspect, wherein a cylindrical portion extending in an outer peripheral direction from a folded portion of the core metal is formed on the convex portion formed on the one member. It is characterized by being in pressure contact.

  An oil seal according to a third aspect of the present invention is the oil seal according to the first aspect, wherein a seal pressing part fixed by a fixed sealing portion on the outer peripheral side of the core metal is formed on the one member. It is characterized by being in pressure contact with the part.

  The present invention has the following effects.

  That is, since the oil seal of the present invention having the above-described configuration is provided with a plurality of dust seal lips formed integrally with the oil seal lip, the function of sealing the object to be sealed with only one oil seal and muddy water, Both functions of sealing dust such as foreign matter can be ensured. Therefore, since only one oil seal is mounted, the mounting work is simplified and the mounting can be performed in a narrow space, so that processing of the mounting portion for mounting the oil seal can be reduced.

  Further, in the oil seal according to the second aspect, the cylindrical portion extending in the outer peripheral direction from the folded portion of the core metal is adapted to press contact with the convex portion formed on the one member. This eliminates the need for a seal pressing part to be fixed in the gap, thereby further simplifying the mounting operation. Further, since the cylindrical portion of the cored bar and the fixed sealing portion cooperate and seal so as to sandwich the convex portion formed on the one member, the sealing performance for the one member can be improved.

  Further, in the oil seal according to the third aspect, the seal pressing part fixed by the fixed sealing portion on the outer peripheral side of the core metal comes into pressure contact with the convex portion formed on the one member. It is not necessary to mount the seal pressing part as a separate body when inserting the ring into the annular gap, and the mounting operation can be further simplified. Further, since the seal pressing part and the fixed sealing portion cooperate and seal so as to sandwich the convex portion formed on one member, the sealing performance for one member can be improved.

  Preferred embodiments of the present invention will be described below with reference to the drawings. However, the scope of the present invention is not intended to be limited to the contents described in this embodiment unless otherwise specified.

First Embodiment FIG. 1 is a cross-sectional view of an oil seal 1 according to a first embodiment of the present invention. The oil seal 1 is a core metal 10 fitted in a housing 2 and vulcanized to the core metal 10. The seal sealing part 20 of the rubber-like elastic body which adhere | attaches, and the garter spring 30 with which the recessed part currently formed in the seal sealing part 20 is mounted | worn is provided.

  The cored bar 10 is fitted in the housing 2 via a fixed sealing part 21 described later, and the first turned back in the outer peripheral direction at the sealed fluid side B terminal of the first cylindrical part 11. A first cylindrical portion, a second cylindrical portion 13 extending from the first folded portion 12 toward the outer peripheral side of the atmosphere side A and having an end surface 18 in pressure contact with the side end surface 4 of the convex portion 3 formed on the housing. A second folded portion 14 folded back in the inner circumferential direction at the atmosphere side A terminal of the portion 11, a third cylindrical portion 15 extending from the second folded portion 14 toward the sealed fluid side B inner circumferential direction, and a third cylindrical portion 15, the flange portion 16 extending in the inner circumferential direction from the sealed fluid side B terminal, and as shown in FIG. 2, the second cylindrical portion 13 starts in the radial direction (β direction in the drawing). ) To move.

  The seal sealing portion 20 includes a fixed sealing portion 21 that covers the cylindrical portion of the core metal 10 and contacts the housing 2, and a seal main body portion that is integrally formed with the fixed sealing portion 21 and is vulcanized and bonded to the flange portion 16 of the core metal 10. 22. The seal body 22 includes an oil seal lip 23 positioned on the sealing fluid side B from the flange portion 16 of the core metal 10, a sub seal lip 24 positioned on the atmosphere side A from the oil seal lip 23, and a flange portion of the core metal 10. A first dust seal lip 25 which seals foreign matter such as muddy water and dust from the atmosphere side A by being positioned on the atmosphere side A from 16 and sliding with the shaft toward the atmosphere side A; And a second dust seal lip 26 located on the sealing fluid side B. A garter spring 30 is attached to a recess formed on the outer peripheral side of the oil seal lip 23 opposite to the lip edge to give the oil seal lip 23 a radial tightness.

  The oil seal 1 has an annular gap formed between the housing 2 and the shaft from the air side A toward the sealed fluid side B (α direction in the figure) with the oil seal lip 23 side (left side in the figure) as the head. Since the second cylindrical portion 13 of the core metal 10 moves in the inner circumferential direction (β direction in the figure) starting from the first folded portion 12, the second cylindrical portion 13 can be easily inserted. When the end surface 18 of the second cylindrical portion 13 reaches the sealed fluid side B from the position of the side end surface 4 of the convex portion 3 formed on the housing 2, the end portion 17 of the second cylindrical portion 13 is made to be the first folded portion 12 due to the rigidity of the cored bar 10. The end surface 18 of the second cylindrical portion 13 is moved toward the housing 2 side in the outer peripheral direction (γ direction in the figure) from the starting point so that the end surface 18 of the second cylindrical portion 13 is the side end surface 4 of the convex portion 3 formed on the housing 2. The oil seal 1 is inserted into the annular gap. It is possible to fix without the use of Le compressor bar. In addition, since the end surface 18 of the second cylindrical portion 13 and the sealing fluid side end surface 27 of the convex portion 21A of the fixed sealing portion 21 cooperate and seal so as to sandwich the convex portion 3 formed in the housing 2, the housing 2 can be improved.

  Further, the oil seal 1 fixed in the annular gap has an oil seal lip 23 and a sub-seal lip 24 that mainly seal oil, and a plurality of dust seal lips including a first dust seal lip 25 and a second dust seal lip 26 at the tip. Since the part slides with the shaft toward the atmosphere side, foreign matter such as muddy water and dust can be reliably sealed, so it is not necessary to install a separate dust seal from the oil seal 1 and the oil in the annular gap It is possible to easily perform the mounting operation of the seal.

  Further, since no dust seal is required and only one oil seal 1 is mounted, mounting in a narrow space is possible, and the processing of the mounting portion can be performed by processing the portion where the oil seal 1 is mounted, so the processing range is reduced. Furthermore, since the backlash in the axial direction of the oil seal 1 can be prevented without using a conventionally used seal pressing part (snap ring), the number of parts can be reduced and the mounting work can be made more efficient. It becomes possible.

Second Embodiment FIG. 3 is an oil seal according to a second embodiment of the present invention. Unlike the first embodiment, the position of the second folded portion 14 of the cored bar 10 is projected to the atmosphere side A from the position of the atmosphere side end face 5 of the housing 2. Thereby, the rigidity of the convex portion 21A of the fixed sealing portion 21 can be increased, and the end surface 18 of the second cylindrical portion 13 of the core metal 10 and the sealing fluid side end surface 27 of the convex portion 21A of the fixed sealing portion 21 are attached to the housing 2. It is possible to further improve the sealing performance when the sealing is performed in cooperation so as to sandwich the formed convex portion 3 as compared with the first embodiment. Others are the same as in the first embodiment.

Third Embodiment FIG. 4 shows a third embodiment of the present invention. Unlike the first embodiment, the metal core 10 has only the first folded portion 12 extending in the outer peripheral direction, has no second cylindrical portion, and has a crown-shaped seal pressing part 31 as shown in FIG. 11 is fixed to the outer peripheral portion 21B of the fixed sealing portion 21 by integral vulcanization so that one end portion 31a abuts on the atmosphere side A side surface 12a of the first folded portion 12.

  When the oil seal 1 is inserted from the atmosphere side A in the arrow α direction into the annular space formed between the housing 2 and the shaft from the oil seal lip 23 side (left side in the figure), it is shown in FIG. As the other end portion 31b moves to the position indicated by the chain line in the inner circumferential direction (arrow β direction), the seal pressing component 31 is easily moved to the position indicated by the chain line in the inner peripheral direction (arrow β direction). When the other end portion 31b reaches the sealing fluid side B from the side end face 4 of the convex portion 3 formed on the housing, the other end portion 31b can be inserted in the outer circumferential direction due to the rigidity of the seal pressing component 31. Since the position returns to the position indicated by the dotted line (in the direction of the arrow γ), the other end 31b can be brought into pressure contact with the side end face 4 of the convex portion 3 of the housing 2, and the oil seal 1 can be fixed to the annular gap. It becomes. Further, since the other end portion 31b of the seal pressing part 31 and the sealing fluid side end surface 27 of the convex portion 21A of the fixed sealing portion 21 cooperate and seal so as to sandwich the convex portion 3 formed in the housing 2. It becomes possible to improve the sealing performance with respect to the housing 2.

  Further, the oil seal 1 fixed in the annular gap has an oil seal lip 23 and a sub-seal lip 24 that mainly seal oil, and a plurality of dust seal lips including a first dust seal lip 25 and a second dust seal lip 26 at the tip. Since the part slides with the shaft toward the atmosphere side, foreign matter such as muddy water and dust can be reliably sealed, so it is not necessary to install a separate dust seal from the oil seal 1 and the oil in the annular gap It is possible to easily perform the mounting operation of the seal.

  Further, since no dust seal is required and only one oil seal 1 is mounted, mounting in a narrow space is possible, and the processing of the mounting portion can be performed by processing the portion where the oil seal 1 is mounted, so the processing range is reduced. Furthermore, since it is possible to prevent backlash in the axial direction of the oil seal 1 without mounting the conventionally used seal holding parts separately, the number of parts can be reduced and the mounting work can be made more efficient. It becomes.

  In the first to third embodiments, a concave portion is formed on the outer peripheral side opposite to the lip edge of the first dust seal lip 25, and a garter spring 30 is attached to the concave portion to reinforce the compression force on the shaft of the dust seal lip. You may make it do.

Sectional drawing of the oil seal which concerns on 1st Example of this invention P section enlarged sectional view of FIG. Sectional drawing of the oil seal which concerns on 2nd Example of this invention. Sectional drawing of the oil seal which concerns on 3rd Example of this invention. Part P enlarged sectional view of FIG. (1) Perspective view, (2) Plan view, (3) Front view of seal holding parts Sectional view of oil seal and dust seal according to conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oil seal 2 Housing 3,21A Convex part 4,5,18,27 End surface 10 Core metal 11,13,15 Cylindrical part 12,14 Folded part 16 Flange part 17 End part 20 Seal sealing part 21 Fixed sealing part 21B Outer peripheral part 22 Seal body 23, 24, 25, 26 Seal lip 30 Garter spring 31 Seal holding part (snap ring)
A Atmosphere side B Sealed fluid side

Claims (3)

  An oil seal installed in an annular gap between two members assembled so as to be movable relative to each other, and a cored bar fitted into one member, vulcanized and bonded to the cored bar, and slidably contacted with another member An oil seal lip that seals an object to be sealed, and an oil seal lip that is positioned on the atmosphere side of the oil seal lip and that slides against the other member with the tip end facing the atmosphere and seals external dust and the like are integrally formed. And an oil seal having a plurality of dust seal lips.   2. The oil seal according to claim 1, wherein a cylindrical portion extending in an outer peripheral direction from the folded portion of the core metal is in pressure contact with a convex portion formed on the one member.   2. The oil seal according to claim 1, wherein a seal pressing component fixed by a fixed sealing portion on an outer peripheral side of the core metal is in pressure contact with a convex portion formed on the one member.

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