JPH0448370Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to a peripheral metal fitting type oil seal in which the outer surface of the outer periphery of a reinforcing ring is fitted into a housing.

"Problems to be solved by conventional techniques and ideas" In general, in oil seals of the type in which the outer surface of the outer periphery of the metal reinforcing ring is fitted into the housing,
The outer circumferential portion is formed to have a uniform outer diameter with a required fitting allowance, and a sealant is applied to the entire outer circumferential surface.

Therefore, when assembling a conventional oil seal of this type into a housing, it is not easy to fit.
Automobile manufacturers use a special pushing jig that applies powerful pressure evenly around the entire circumference of the oil seal, but other auto repair shops do not have such a special jig.
Every time an engine is disassembled and maintained, the housing is hammered into the housing.

However, when using a hammer to hammer in the housing, it does not bite into the housing, so when you hit one part, other parts lift up, making it extremely difficult to fit. There were problems such as deformation of the oil seal.

Additionally, if sealant is applied to the proximal end of the outer periphery but not to the distal end, it will be extremely difficult to fit the outer periphery into the aluminum housing, and the strong press-fitting load will force the sealant to fit. If it is fitted, it will seriously damage the inner surface of the housing and cause problems such as unstable sealing and deformation of the oil seal, so currently it is necessary to apply it to the entire outer periphery. In the case where the sealant is applied to the entire housing, there is a problem in that the sealant is scraped off by the housing edges when the housing is fitted, and sealant scum peeled off from this area adheres to the lip portion, deteriorating the sealing performance.

Therefore, it was considered to apply the sealant as thinly as possible, but it is technically extremely difficult to apply it as thinly as possible, and furthermore, if there are scratches on the housing, the sealing performance becomes unstable, so scraping off the sealant was difficult. At present, it is necessary to apply a thick coating to the entire outer periphery, despite problems such as a large amount of coating and an increase in manufacturing costs.

``Means for solving problems'' This invention aims to solve the above-mentioned conventional problems.
In the outer periphery metal fitting type oil seal that fits and seals the outer periphery of the reinforcing ring 1 into the housing H, the outer periphery 4 of the reinforcing ring 1 is crimped and fitted to the housing with a required fitting allowance on the proximal end side. A crimp-fitting part 4a is provided on the distal end side of the outer circumferential part 4, and an insertion-fitting part 4b having an outer diameter slightly smaller than the inner diameter of the housing and having a substantially uniform outer dimension is provided. Between the joint part 4a and the insertion fitting part 4b, a minute step part 4c with a taper or radius whose outer diameter gradually decreases from the crimp fitting part 4a to the insertion fitting part 4b is provided, and the crimp fitting part This paper proposes an outer periphery metal fitting type oil seal in which a sealant 5 is applied to the outer periphery of the oil seal 4a.

"Operation" When fitting the oil seal having the above structure into the housing H, first, the fitting part 4b at the tip of the outer peripheral part 4 of the reinforcing ring 1 is fitted into the housing H by hand or using a pushing jig or the like.

At this time, since the fitting part 4b is formed to have an outer diameter slightly smaller than the inner diameter of the housing H, and the outer dimensions are almost uniform, this part can be easily pushed into the housing H to prevent rattling. It is possible to stably position and hold the oil seal in a fitted state with the entire circumference uniformly without causing it to fall off, and it also maintains a stable position even when hit by a hammer without lifting other parts. It ensures adhesion and enables easy and smooth driving.

Then, in this state, when the reinforcement ring is press-fitted using a pushing jig or the like or by hitting it with a hammer, the outer peripheral part 4 of the reinforcing ring is smoothly guided to the slope of the stepped part 4c with respect to the inner peripheral surface of the housing H. It moves from the insertion fitting part 4b to the crimp fitting part 4a, and is fitted and fixed with a required fitting margin in the crimp fitting part 4a, and secure sealing performance is maintained by the sealant 5 applied to the outer periphery. , it is possible to stably fit the housing without scraping the sealant or damaging the housing.

``Example'' Below, an example of this invention shown in the drawings will be described. The reinforcing ring 1 is formed of a metal plate into an annular shape with a substantially L-shaped cross section. A seal lip 3 made of heat-resistant rubber such as fluorine rubber is formed on the portion, and an outer peripheral portion 4 raised from the flange portion 2 is provided.

The outer circumferential portion 4 has a crimp fitting portion 4a on its proximal end side that is crimp-fitted to the housing H with a required fitting margin.
Further, an insertion portion 4b having an outer diameter slightly smaller than the inner diameter of the housing H and having substantially uniform outer dimensions is provided on the distal end side.

A minute step portion 4c is provided between the crimp fitting portion 4a and the insertion fitting portion 4b, and the outer diameter of this step portion 4c gradually decreases from the crimp fitting portion 4a to the insertion fitting portion 4b. It is tapered or rounded.

The insertion part 4b has an outer diameter that can be easily pushed into the housing H by hand or using a pushing jig, etc., and that it does not wobble or easily fall off after being pushed. The fitting width is set to be sufficient to stably hold the entire oil seal in the housing H.

Furthermore, the width of the fitting portion 4b is made relatively larger for oil seals with larger outer diameters, where the portion on which the impact force of the hammer acts has a smaller proportion of the entire oil seal, so that it bites deeper into the housing H. However, in view of the sealing performance of the crimp-fitting portion 4a, the dimensions are set within a range that can maintain the sealing performance of this portion.

Note that a bent portion 4d bent inwardly into an arc, cone, or hook shape is formed at the distal end of the insertion portion 4b, if necessary.

A sealant 5 is applied to the outer circumferential surface of the crimp fitting portion 4a, and this sealant is preferably a sealant with good adhesion and compressive fluidity and low shearing force, such as a rubber latex such as acrylic rubber and low molecular weight tetrafluoroethylene. A compound containing fine resin powder is used.

In addition, in the illustrated embodiment, the inserting portion 4b is formed by cutting the inner circumferential surface of this portion to facilitate bending, or by press forming at the same time as the drawing of the reinforcing ring 1, so that the plate thickness can be reduced. 1/2 of the material board thickness
Although the thickness is reduced to about 2/3, it is possible to form the material plate with the same thickness, so there is no need to make this part thinner than the crimp fitting part 4a.

"Effect of the invention" As described above, according to this invention, a crimp fitting part is provided on the proximal end side of the outer periphery of the reinforcing ring to be crimped to the housing with a required fitting allowance, and Since the fitting part is provided with an outer diameter that is slightly smaller than the inner diameter of the housing and has a uniform outer diameter, when fitting the oil seal, first push the fitting part into the housing to prevent the oil seal from playing against the housing. It is possible to stably position and maintain the mating state with no sticking or falling off, and the entire circumference is evenly mated, and even when hit locally by a hammer, stable biting is achieved without lifting other parts. It is possible to ensure the stability and to perform striking easily and smoothly.

Furthermore, a minute stepped portion with a taper or radius whose outer diameter gradually decreases from the crimp fitting portion to the insertion fitting portion is provided between the crimp fitting portion and the insertion fitting portion. When the parts are in a stable and even partially fitted state, the oil seal can be moved extremely smoothly from the insertion part to the crimp fitting part, even when hit with a hammer as well as a press-fitting jig, and the oil seal can be completely fixed without any differences among workers. The reinforcing ring can be fitted into the housing smoothly and reliably without deforming it, and the ease of assembly can be greatly improved.

In addition, since the sealant is applied to the crimp fitting, only a small amount of sealant is required, which reduces costs.It also maintains sealing properties and prevents scraping of the sealant and damage to the housing. This makes it possible to stably fit the parts together without any problems.

[Brief explanation of the drawing]

FIG. 1 is a partial longitudinal sectional view of the oil seal of this invention, and FIG. 2 is a front view thereof. DESCRIPTION OF SYMBOLS 1...Reinforcement ring, 4...Outer peripheral part, 4a...Crimp fitting part, 4b...Insertion fitting part, 4c...Step part, 4d...
...Bending portion, 5...Sealant.

Claims (1)

[Scope of utility model registration request] In an outer periphery metal fitting type oil seal in which the outer periphery of the reinforcing ring is fitted and sealed to the housing, a crimp fit is provided in which the outer periphery of the reinforcing ring is crimped to the housing with a required fitting margin on the proximal end side. A mating part is provided, and a fitting part is provided on the tip side of the outer circumferential part and has an outer diameter slightly smaller than the inner diameter of the housing and has a substantially uniform outer dimension, and the crimp fitting part and the fitting part A small stepped portion with a taper or radius is provided between the crimp fitting portion and the insertion fitting portion, the outer diameter of which gradually decreases from the crimp fitting portion to the insertion fitting portion, and a sealant is applied to the outer periphery of the crimp fitting portion. A metal-fitting oil seal on the outer periphery.