JP2009074644A - Oil seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a reliability of rust prevention of a metal ring 1, and prevent workability from being damaged when manufacturing the metal ring 1 in an oil seal including a structure in which the periphery of the metal ring 1 is exposed from a fixed oil seal portion 5. <P>SOLUTION: The oil seal is characterized in that a seal lip 2 and its peripheral side fixed seal portion 5 are integrally formed of rubber elastic material with the metal ring 1 with the metal ring 1 molded from steel plate surface-treated by rustproofing, and its periphery 11a exposed from the fixed seal portion 5, and keeps a fixing force by an exposed portion of the metal ring 1 and a sealing performance by the fixed seal portion 5 secured simultaneously, thereby planning rustproofing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an oil seal used for sealing the outer periphery of a rotating body in automobiles, general machines, industrial machines, and the like.

  FIG. 3 is a half sectional view showing a conventional oil seal 100 cut along a plane passing through its axis. As shown in FIG. 3, this type of oil seal 100 is formed in a ring shape with a rubber-like elastic material, and is fixedly fitted to an inner peripheral surface of a shaft hole housing (not shown). And a seal lip 103 that is slidably in close contact with the outer peripheral surface of the rotating shaft (not shown) on the inner peripheral side thereof is formed continuously with the intermediate radial direction portion 102 from the fixed seal portion 101. A reinforcing metal ring 104 is integrally embedded over the intermediate radial direction portion 102. Further, the outer periphery of the seal lip 103 is formed in a groove shape that is continuous in the circumferential direction, and compensates for a decrease in the tightening force due to permanent deformation of the seal lip 103, and ensures a radial followability with respect to the rotating shaft. 105 is fitted.

  That is, in the oil seal 100, a fixed seal portion 101 is press-fitted into an inner peripheral surface of a shaft hole housing (not shown), and a tip inner peripheral portion of the seal lip 103 is inserted into the shaft hole housing (not shown). A shaft seal function is achieved by being slidably brought into close contact with the outer peripheral surface of the rotary shaft, and the fluid to be sealed (oil) on the side facing the seal lip 103 is prevented from leaking from the shaft periphery to the outside of the machine. Yes (for example, see Patent Document 1 below).

  However, in the fixed seal portion 101 made of rubber-like elastic material as shown in the example shown in the figure, the compression reaction force is reduced in the low temperature region where the rubber-like elastic material becomes brittle because it is fitted to the inner peripheral surface of the housing. In the case where the fixing to the housing depends only on the fitting force of the fixed seal portion 101, the oil seal 100 may move to the outside of the machine due to an increase in the pressure in the machine and fall off.

  Further, in order to increase the fixing force with respect to the housing while ensuring good sealing performance with the housing, as in the following Patent Document 2, as the structure in which the outer peripheral surface of the metal ring is exposed from the fixed seal portion, It is effective to press both the outer peripheral surface of the metal ring and the fixed seal part made of rubber-like elastic material against the inner peripheral surface of the housing. In this case, however, the reliability of the metal ring against rust is improved. There is concern about the decline.

It is effective to use SUS material (stainless steel) as a metal ring material for rust prevention of metal rings. Due to the presence of the fixed seal portion, it is difficult to repair scratches by polishing, and there has been a problem in using a SUS material for the metal ring of the oil seal of the type as in Patent Document 2.
JP 2002-206644 A JP 2004-18865 A

  The present invention has been made in view of the above points, and a technical problem thereof is that an oil seal having a structure in which an outer peripheral surface of a metal ring is exposed from a fixed seal portion, It is to improve the reliability of rust prevention and to prevent deterioration of workability when producing a metal ring.

  As a means for effectively solving the technical problem described above, an oil seal according to the present invention includes a seal lip and a fixed seal portion on the outer peripheral side thereof, which are integrally formed with a rubber-like elastic material on a metal ring. The metal ring is made of a steel plate whose surface is rust-proofed, and its outer peripheral surface is exposed from the fixed seal portion.

  More preferably, in the configuration of the invention, the rust-proof steel plate is a plated steel plate, and the base material is a cold-rolled steel plate.

  According to the oil seal according to the present invention, since the metal ring is made of a rust-proof steel plate, the outer peripheral surface exposed from the fixed seal portion is highly reliable in rust prevention, and is fixed by the exposed portion of the metal ring. It is possible to achieve a structure in which both the force and the sealing performance by the fixed seal portion are ensured.

  In addition, the steel plate that has been rust-proofed is a plated steel plate, so that it has high rust-proof reliability and the metal ring base material is made of a cold-rolled steel plate. It is possible to ensure good workability when manufacturing the ring.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view showing a preferred embodiment of an oil seal according to the present invention by cutting along a plane passing through an axis, and FIG. 2 shows a metal ring used in the oil seal of FIG. It is the one side sectional view cut and shown by the plane which passes through.

  The oil seal shown in FIG. 1 is obtained by integrally providing a metal ring 1 with a seal lip 2, a dust lip 3, and a fixed seal portion 5. The seal lip 2, the dust lip 3, and the fixed seal portion 5 on the outer peripheral side thereof are made of a rubber-like elastic material and are continuous with each other via a base portion 4 that is integrally vulcanized and bonded to the metal ring 1. . A garter spring 6 is mounted on the outer peripheral surface near the tip of the seal lip 2.

  Among these, the metal ring 1 is a press-formed product, and as shown in FIG. 2, the metal ring 1 is made of a material obtained by subjecting a base material 1a made of a cold-rolled steel plate such as SPCC to rust prevention processing by a surface treatment 1b. It has a cylindrical portion 11, a fixed seal support portion 12 formed with an appropriate small diameter on the tip side thereof, and an inward flange portion 13 extending from the opposite end portion to the inner peripheral side.

  The seal lip 2 is the direction in which the fixed seal support portion 12 of the metal ring 1 faces from the inner peripheral end 4a of the base portion 4 reaching the inner peripheral position of the inward flange portion 13 of the metal ring 1 (the inside of the machine in the mounted state). A lip edge 21 having a mountain-shaped cross section extending in the circumferential direction and slidably in contact with the outer peripheral surface of the rotation shaft (not shown) is formed on the inner periphery in the vicinity of the tip 2a. The inclined surface (conical surface) 2b opposite to the tip 2a generates a number of screw pump forces that push the surrounding fluid in the direction in which the tip 2a of the seal lip 2 faces (inner side) by the rotation of the rotating shaft. A screw protrusion 22 is formed.

  The dust lip 3 extends from the inner peripheral end 4a of the base portion 4 reaching the inner peripheral position of the inward flange portion 13 of the metal ring 1 to the side opposite to the seal lip 2 (the direction toward the outside in the mounted state). The inner peripheral portion is slidably brought into close contact with an outer peripheral surface of a rotating shaft (not shown) or with a slight gap.

  The base portion 4 encloses the inward flange portion 13 of the metal ring 1 and extends from the inward flange portion 13 while being joined to the inner peripheral surface of the outer peripheral cylindrical portion 11 and the fixed seal support portion 12. 5 is formed in the part which went around from the said base part 4 to the outer peripheral side of the said fixed seal | sticker support part 12. As shown in FIG. Accordingly, the inward flange portion 13 of the metal ring 1 is encapsulated in the base portion 4, and the fixed seal support portion 12 of the metal ring 1 is encapsulated in the base portion 4 and the fixed seal portion 5. The outer peripheral cylindrical portion 11 is in a state where the outer peripheral surface 11a is exposed while the inner peripheral surface is encapsulated by the base portion 4.

  The garter spring 6 is formed by connecting metal coil springs in an annular shape, and is fitted into an annular groove formed on the outer peripheral surface of the seal lip 2 near the tip 2a.

  In the manufacture of the oil seal configured as described above, first, a cold-rolled steel sheet such as SPCC, which has been subjected to surface treatment 1b for rust prevention on the surface in advance, is plastic processed into the shape shown in FIG. Alternatively, the metal ring 1 is obtained by subjecting a cold-rolled steel sheet such as the SPCC to a shape shown in FIG. 2 and then performing a surface treatment 1b for rust prevention on the surface thereof. Since cold-rolled steel sheets such as SPCC have better workability than SUS materials (stainless steel), they can be easily processed into the shape shown in FIG.

  As the surface treatment 1b for rust prevention, phosphate film treatment, black chromate treatment, colored chromate treatment, Unichrome treatment, zinc plating treatment, dissolved zinc-Al-Mg alloy plating treatment, and the like are conceivable. Among these, in the surface treatment other than the plating treatment, the colored chromate treatment is preferable in consideration of the cost and the reliability of rust prevention.

  Moreover, in order to further improve rust prevention, it is preferable to use a molten zinc-Al-Mg alloy-plated steel sheet. Since the molten zinc-Al-Mg alloy-plated steel sheet has a harder plating film than normal galvanization, it is possible to suppress peeling and rusting due to scratches. Moreover, as compared with the case where galvanization or the like is performed on the surface after plastic processing into the shape shown in FIG. 2, the punched portion (tip surface 12a and inward flange portion of the fixed seal support portion 12) The adhesiveness of the inner peripheral end face 13a) of 13 is improved. That is, if a plated steel sheet that has already been plated with a molten zinc-Al-Mg alloy is used, there is no plating layer with poor adhesion to rubber on the end faces 12a and 13a by punching with a press. In this part, the same adhesiveness as that of the steel plate without plating can be secured.

  Next, a vulcanized adhesive is applied to the metal ring 1 manufactured as described above and dried, and then this is positioned and set in a rubber vulcanization mold (not shown) and clamped, A molding cavity defined between the mold and the metal ring 1 is filled with an unvulcanized rubber material, and heated and pressurized, so that the seal lip 2, the dust lip 3, the base 4 and the fixed seal portion. 5 is vulcanized and bonded to the metal ring 1 simultaneously with vulcanization molding. As a result, the oil seal shown in FIG. 1 can be obtained.

  This oil seal is incorporated into the inner periphery of a housing (not shown) so that the seal lip 2 faces the inside of the machine, and the lip edge 21 of the seal lip 2 is slidably in contact with the outer peripheral surface of the rotary shaft. Thus, the oil to be sealed in the machine is prevented from leaking from the shaft periphery to the outside of the machine, and the dust seal 3 prevents foreign substances in the atmosphere outside the machine from entering the machine.

  In this mounted state, since the outer peripheral surface of the outer peripheral cylindrical portion 11 of the metal ring 1 is metal-fitted with the inner peripheral surface of the housing, a large fixing force against a load in the pulling direction can be obtained, and a rubber-like elastic material Since the fixed seal portion 5 made of this is in close contact with the inner peripheral surface of the housing with an appropriate crushing allowance, good sealing performance between the housing and the housing is ensured. Moreover, since the metal ring 1 is rust-prevented by the plating film, rust is generated on the outer peripheral surface of the outer peripheral cylindrical portion 11 exposed from the base portion 4 and the fixed seal portion 5 made of a rubber-like elastic material, or due to that. Thus, it is possible to effectively prevent the rubber-like elastic material from being peeled off.

1 is a half sectional view showing a preferred embodiment of an oil seal according to the present invention by cutting along a plane passing through an axis. It is a half sectional view which cuts and shows the metal ring used for the oil seal of FIG. 1 by the plane which passes along an axial center. It is the one side sectional view which cuts and shows oil seal 100 by conventional technology by the plane which passes along the axis.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal ring 1a Base material 1b Surface treatment 11 Outer peripheral cylinder part 11a Outer peripheral surface 12 Fixed seal support part 13 Inward flange part 2 Seal lip 3 Dustrip 4 Base part 5 Fixed seal part 6 Garter spring

Claims (3)

  A seal lip and a fixed seal portion on the outer peripheral side thereof are integrally formed on a metal ring by a rubber-like elastic material, and the metal ring is made of a steel plate whose surface is rust-proofed, and the outer peripheral surface thereof is the aforementioned An oil seal that is exposed from a fixed seal portion.   The oil seal according to claim 1, wherein the rust-proof steel plate is a plated steel plate.   The oil seal according to claim 1, wherein the base metal of the metal ring is made of a cold rolled steel plate.

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