JP2009068672A - Sealing device, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a sealing device having a main lip 2, a dust lip 3, and a backup ring 5 supporting the main lip 2 into a single component. <P>SOLUTION: The main lip 2 formed of a rubber-like elastic material is integrally arranged at one axial side of an inner peripheral part of a mounting ring 1; the dust lip 3 formed of a rubber-like elastic material is integrally arranged at the axial other side of the inner peripheral part of the mounting ring 1; the backup ring 5 supporting the main lip 2 from the atmosphere side and the inner peripheral side is fitted between a fitting recessed part 1a continuously formed in the circumferential direction at the one axial side of the inner peripheral part of the mounting ring 1, and the main lip 2; a required number of grooves 1b reaching the outer-diameter side relative to the fitting recessed part 1a from the inner peripheral edge of the fitting recessed part 1a is formed at the one axial side of the inner peripheral part of the mounting ring 1; and the main lip 2 and the dust lip 3 are continued to each other through the rubber-like elastic material filled in the groove 1b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sealing device used for, for example, a hydraulic shock absorber and a manufacturing method thereof.

  A hydraulic shock absorber (shock absorber) of a vehicle is provided with a sealing device for sealing the circumference of the piston rod. FIG. 5 is a half sectional view of a conventional sealing device cut into a plane passing through its axis O and shown in a mounted state on a hydraulic shock absorber, and FIG. 6 is a half sectional view of the unmounted and separated state. .

  The conventional sealing device shown in FIG. 5 includes an oil seal 101 that seals hydraulic oil inside a hydraulic shock absorber, a dust seal 102 that prevents entry of dust and muddy water from the outside, and a backup ring 103. Prepare. Both the seals 101 and 102 are sandwiched between a caulking portion at the opening end of the housing 111 in the hydraulic shock absorber and a rod guide 112 inside the metal mounting rings 101a and 102a on the outer periphery.

  The oil seal 101 seals between the housing 111 and the rod guide 112, and the main lip 101b, which is slidably brought into close contact with the outer peripheral surface of the piston rod 113 with the mounting ring 101a facing inward in the axial direction. The outer peripheral lip 101c is integrally formed of a rubber-like elastic material, and the dust seal 102 is slidably brought into close contact with the outer peripheral surface of the piston rod 113 in the state facing the outer side in the axial direction to the mounting ring 102a. The dust lip 102b is integrally formed of a rubber-like elastic material. The backup ring 103 is made of a synthetic resin, and is disposed on the inner periphery of the main lip 101 b of the oil seal 101 on the air side from the sliding surface S with the piston rod 113, and the mounting ring of the dust seal 102. The main lip 101b is supported between the inner peripheral side and the inner peripheral side of the main lip 101b.

  That is, this sealing device prevents the internal hydraulic fluid from flowing out of the hydraulic shock absorber by bringing the main lip 101b of the oil seal 101 into close contact with the outer peripheral surface of the piston rod 113 with an appropriate tightening allowance. The dust seal 102 prevents foreign matter from entering the inside of the hydraulic shock absorber from the outside by bringing the dust lip 102b into close contact with the outer peripheral surface of the piston rod 113 with an appropriate tightening allowance. Further, when the pressure of the hydraulic oil increases with the operation of the piston inside the hydraulic shock absorber, this hydraulic pressure acts on the main lip 101b so as to increase the pressing force against the outer peripheral surface of the piston rod 113. Since 101b is supported from the atmosphere side and the inner peripheral side by the backup ring 103, an increase in the tightening force of the main lip 101b is effectively suppressed and its pressure resistance is maintained (see, for example, Patent Document 1).

  Here, in the case of a structure in which the backup ring 103 for supporting the main lip 101b is not provided, the main lip 101b and the dust lip 102b are continuously formed on the inner periphery of one mounting ring, thereby forming a single sealing device. (See, for example, Patent Document 2). However, in the case of the sealing device in which the pressure resistance is improved by providing the backup ring 103 as shown in FIG. 6, the rubber-like elastic material constituting the main lip 101 b and the dust lip 102 b is mainly transferred by the backup ring 103. Since it is divided between the lip 101b and the dust lip 102b, the oil lip 101b and the dust ring 102 and the backup ring 103 must be composed of three parts.

Therefore, when assembling to the hydraulic shock absorber, the oil seal 101, the dust seal 102, and the backup ring 103 must be assembled while being overlapped, and the work is complicated and the assemblability is poor. Moreover, since the oil seal 101 and the dust seal 102 need to be manufactured in separate molding processes, there is a problem that the manufacturing cost must be increased.
JP 2005-90569 A Japanese Patent Laid-Open No. 2001-173797

  The present invention has been made in view of the above points, and the technical problem is to provide a sealing device having a main lip, a dust lip, and a backup ring that supports the main lip. It is to make parts.

  As a means for effectively solving the technical problem described above, the sealing device according to the invention of claim 1 is characterized in that a main lip made of a rubber-like elastic material is integrally formed on one side in the axial direction of the inner peripheral portion of the mounting ring. A dust ring made of a rubber-like elastic material is integrally provided on the other axial side of the inner peripheral portion of the mounting ring, and a backup ring for supporting the main lip from the atmosphere side and the inner peripheral side is provided with the mounting ring. Between the fitting recess formed continuously in the circumferential direction on one side in the axial direction of the inner peripheral part and the main lip, and on the one side in the axial direction of the inner peripheral part of the mounting ring. A required number of grooves are formed from the inner peripheral edge of the mating recess to reach the outer diameter side from the fitting recess, and the main lip and the dust lip are continuously connected to each other via a rubber-like elastic material filled in the groove. It is what.

  According to a second aspect of the present invention, there is provided a manufacturing method of a sealing device, wherein the sealing recess according to the first aspect of the present invention is formed in a fitting recess continuous in the circumferential direction on one axial side of the inner peripheral portion of the mounting ring. The required number of grooves reaching the outer diameter side from the fitting recess from the inner peripheral edge of the fitting recess are formed, and the mounting ring is installed in the mold with the backup ring fitted in the fitting recess. The mold is used to shape the unvulcanized rubber material through the grooves into the main lip molding cavity and the dust lip molding cavity defined on both axial sides of the inner periphery of the mounting ring. is there.

  According to the sealing device of the present invention, since the main lip, the dust lip, and the backup ring are integrated with the mounting ring, the backup ring does not fall off during the assembly to the device. And the backup ring is fitted between the main lip and the fitting recess formed on one side in the axial direction of the inner circumference of the mounting ring. In addition, the main lip and the backup ring are connected to each other via a rubber-like elastic material filled in the groove on the inner periphery of the mounting ring. Despite having the structure, the main lip and the backup ring can be manufactured in a single molding process, and can be provided at low cost.

  According to the manufacturing method of the sealing device according to the present invention, the axial direction of the inner peripheral portion of the mounting ring can be achieved even when the backup ring is fitted to the fitting recess formed on one side in the axial direction of the inner peripheral portion of the mounting ring. The main lip molding cavity and the dust lip molding cavity defined on both sides are not blocked by the backup ring and communicate with each other through the groove, so the main lip and the backup ring are molded at once. Manufacturing cost can be reduced.

  Hereinafter, preferred embodiments of a sealing device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a half sectional view showing a state where the sealing device according to the present invention is mounted on a hydraulic shock absorber cut along a plane passing through an axis O, and FIG. Fig. 4 is a perspective view of an attachment ring, and Fig. 4 is an explanatory view schematically showing a molding step in the method for manufacturing a sealing device according to the present invention.

  In FIG. 1, reference numeral 111 denotes a housing of a hydraulic shock absorber, reference numeral 112 denotes a rod guide provided on the inner periphery near the end of the housing 111, and reference numeral 113 denotes a shaft hole 112 a on the inner periphery of the rod guide 112. Thus, the piston rod is led out of the housing 111.

  As shown in FIG. 2, the sealing device according to the present invention is integrally provided with a main lip 2 made of a rubber-like elastic material on one side in the axial direction of the inner peripheral portion of the mounting ring 1. A dust lip 3 made of rubber-like elastic material is integrally provided on the other side in the axial direction of the inner peripheral portion, and an outer peripheral lip 4 made of rubber-like elastic material is integrally formed on one side in the axial direction of the outer peripheral portion of the mounting ring 1. A backup ring 5 is provided between the inner peripheral portion of the mounting ring 1 and the main lip 2.

  The attachment ring 1 is sandwiched between a caulking portion 111a at the open end of the housing 111 in the hydraulic shock absorber and the rod guide 112 inside thereof, and as shown in FIG. A fitting recess 1a that is continuous in the circumferential direction is formed on one side in the axial direction of the inner periphery of the inner periphery, and from the inner periphery of the fitting recess 1a, the fitting recess 1a A plurality of grooves 1b extending in the radial direction to the position on the outer diameter side are formed at equal intervals in the circumferential direction (90 ° intervals in the illustrated example).

  The main lip 2 and the dust lip 3 are such that the inner lip edge is slidably in contact with the outer peripheral surface of the piston rod 113, and the taper is such that the tip side has a smaller diameter toward the opposite sides in the axial direction. It extends in a shape. The outer peripheral lip 4 is interposed between the inner peripheral surface of the housing 111 and the end outer peripheral cutout surface 112b of the rod guide 112 in a compressed state. Garter springs 6 and 7 are fitted on the outer peripheries of the main lip 2 and the dust lip 3 to compensate for the tightening force and radial followability.

  The backup ring 5 is made of a synthetic resin having a low friction coefficient that is excellent in wear resistance, such as PTFE, and has an inner diameter slightly larger than the outer diameter of the piston rod 113, that is, loosely inserted into the outer periphery of the piston rod 113. Between the fitting concave portion 1a formed in the inner peripheral portion of the mounting ring 1 and the neck inner peripheral surface 2a closer to the atmosphere than the close sliding portion S1 between the lip edge of the main lip 2 and the piston rod 113. Is fitted. Specifically, the backup ring 5 is tightly fitted in the fitting recess 1a of the mounting ring 1, and a portion protruding in the axial direction from the fitting recess 1a is circular with the neck inner peripheral surface 2a of the main lip 2. It is closely fitted with a stepped surface continuous in the circumferential direction.

  The base portion 2b of the main lip 2 and the base portion 3a of the dust lip 3 formed so as to cover the inner peripheral surface of the mounting ring 1 are bridge portions 8 made of a rubber-like elastic material filled in the groove 1b of the mounting ring 1. The base portion 2b of the main lip 2 and the base portion 4a of the outer peripheral lip 4 are interposed through an elastic layer 9 made of a rubber-like elastic material so as to cover one side of the mounting ring 1 in the axial direction. Are continuous with each other.

  According to the sealing device configured as described above, the main lip 2 is slidably brought into close contact with the outer peripheral surface of the piston rod 113 in the mounted state shown in FIG. Oil is prevented from leaking to the atmosphere side through the axial circumference of the piston rod 113, and the outer peripheral lip 4 seals between the inner peripheral surface of the housing 111 and the rod guide 112. By being slidably brought into close contact with the outer peripheral surface, dust or muddy water on the atmosphere side is prevented from entering the inside of the hydraulic shock absorber through the axial periphery of the piston rod 113.

  Further, when the pressure of the hydraulic oil increases with the operation of the piston inside the hydraulic shock absorber, this hydraulic pressure acts on the main lip 2 so as to increase the pressing force against the outer peripheral surface of the piston rod 113. The lip 2 is supported on the inner peripheral surface 2a of the neck from the atmosphere side and the inner peripheral side by a backup ring 5 having a required rigidity, so that an increase in the tightening force of the main lip 2 is effectively suppressed and its pressure resistance is maintained. Is done.

  In this sealing device, the main lip 2, the dust lip 3, the outer peripheral lip 4 and the backup ring 5 are integrated with the mounting ring 1, so that the backup ring 5 falls off when assembled to the hydraulic shock absorber. Therefore, the assembling property is improved. Moreover, since the backup ring 5 is fitted between the fitting recess 1a formed in the mounting ring 1 and the neck inner peripheral surface 2a of the main lip 2, the main lip 2 can be firmly supported during high pressure action. it can.

  In the production of this sealing device, first, as shown in FIG. 3, a vulcanized adhesive is applied to the mounting ring 1 in which the fitting recess 1a and the groove 1b are formed, and as shown in FIG. With the backup ring 5 fitted in the fitting recess 1a, the mounting ring 1 is positioned and installed in a mold (not shown).

  Next, by clamping the above-described mold, a cavity 10 as shown by a two-dot chain line in FIG. 4 is defined between the mounting ring 1 and the inner surface of the mold. The cavity 10 includes a main lip forming cavity 10a defined on one side in the axial direction of the inner peripheral portion of the mounting ring 1 to which the backup ring 5 is fitted, and the other axial direction side of the inner peripheral portion of the mounting ring 1. A dust lip forming cavity 10b and an outer peripheral lip forming cavity 10c defined on one side in the axial direction of the outer peripheral portion of the mounting ring 1, and the main lip forming cavity 10a and the dust lip molding. The cavity 10b is connected to each other on the inner periphery of the mounting ring 1 through a passage 10d formed between the mounting ring 1 and the backup ring 5 by a plurality of grooves 1b of the mounting ring 1, and is connected to the main lip molding cavity 10a. The outer peripheral lip forming cavity 10c communicates with each other via a disk-shaped gap 10e formed on one side of the mounting ring 1 in the axial direction.

  Next, the unvulcanized rubber material is filled into the cavity 10 through a gate (not shown) opened in a part of the cavity 10 (for example, the main lip molding cavity 10a). This unvulcanized rubber material is continuously shaped into the main lip molding cavity 10a, the dust lip molding cavity 10b and the outer peripheral lip molding cavity 10c through the passage 10d and the disk-shaped gap 10e, and is heated and pressurized. To form the sealing device shown in FIG. That is, the portion filled in the main lip forming cavity 10a becomes the main lip 2, the portion filled in the dust lip forming cavity 10b becomes the dust lip 3, and the portion filled in the outer lip forming cavity 10c. Becomes the outer peripheral lip 4, the portion filled in the passage 10 d becomes the bridging portion 8, and the portion filled in the disc-shaped gap 10 e becomes the elastic layer 9. Further, a part of the unvulcanized rubber material filled in the main lip molding cavity 10 a is shaped following the step surface of the backup ring 5 fitted in the fitting recess 1 a of the mounting ring 1. It hardens | cures in the shape closely-fitted with the backup ring 5 mutually.

  Therefore, the sealing device shown in FIG. 2 forms the main lip 2, the dust lip 3, and the outer peripheral lip 4 at the same time, despite having a backup ring 5 between the main lip 2 and the dust lip 3. Manufacturing cost can be reduced.

1 is a cross-sectional side view of a state in which the sealing device according to the present invention is mounted on a hydraulic shock absorber, cut along a plane passing through an axis O. FIG. 1 is a cross-sectional side view of an unmounted state in which a sealing device according to the present invention is cut along a plane passing through an axis O. FIG. It is a perspective view of the attachment ring in the sealing device concerning the present invention. It is explanatory drawing which shows schematically the formation process in the manufacturing method of the sealing device which concerns on this invention. FIG. 10 is a half cross-sectional view of a conventional sealing device mounted on a hydraulic shock absorber shown by cutting along a plane passing through its axis O. FIG. 6 is a half sectional view of an unmounted and separated state showing a conventional sealing device cut by a plane passing through its axis O.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mounting ring 1a Fitting recessed part 1b Groove 2 Main lip 3 Dustrip 4 Outer lip 5 Backup ring 6, 7 Garter spring 8 Bridging part 9 Elastic layer 10 Cavity 10a Main lip molding cavity 10b Dustrip molding cavity 10c Outer lip Molding cavity 10d Passage 10e Disc-shaped gap 111 Housing 112 Rod guide 113 Piston rod

Claims (2)

  A main lip made of rubber-like elastic material is integrally provided on one side in the axial direction of the inner peripheral portion of the mounting ring, and a dust lip made of rubber-like elastic material is integrally formed on the other side in the axial direction of the inner peripheral portion of the mounting ring. And a fitting recess in which a backup ring for supporting the main lip from the atmosphere side and the inner peripheral side is continuously formed in a circumferential direction on one axial side of the inner peripheral portion of the mounting ring and the main lip. A required number of grooves extending from the inner peripheral edge of the fitting recess to the outer diameter side from the fitting recess are formed on one side in the axial direction of the inner periphery of the mounting ring. The sealing device characterized in that the lip and the dust lip are continuous with each other via a rubber-like elastic material filled in the groove.   On the one side in the axial direction of the inner periphery of the mounting ring, a fitting recess that is continuous in the circumferential direction, and a required number of grooves that reach from the inner periphery of the fitting recess to the outer diameter side from the fitting recess, The mounting ring is installed in a mold with a backup ring fitted in the fitting recess, and a main lip molding cavity defined by the mold on both axial sides of the inner periphery of the mounting ring; An unvulcanized rubber material is shaped into the dust lip molding cavity through the groove.

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