JP2941592B2 - Oil seal and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal for sealing a rotating part, and more particularly, to an oil seal which saves forming material and improves accuracy and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in manufacturing an oil seal, an annular metal ring is punched out of a metal plate material in advance, and the metal ring is drawn or coated with an adhesive, and then is made of synthetic resin or synthetic rubber. The elastic body was vulcanized and bonded in a mold to obtain an oil seal in which the metal ring and the seal portion were integrated.

[0003]

However, the oil seal comprising the metal ring and the seal portion as described above has the following problems in molding the metal ring, and can be a preferable structure for reducing the manufacturing cost and improving the accuracy. Not. That is, in the forming of the metal ring, in many cases, the metal sheet material wound in a belt shape is sequentially sent to a punching punch and continuously punched and formed. It is the minimum required size, and it is 20% when the unnecessary parts of the outer peripheral part and the inner core part are removed.
Only about 30% of effective materials can be used.

Hereinafter, a detailed description will be given with reference to the drawings. As a method of solving this low yield, a method of manufacturing a resource-saving oil seal as disclosed in Japanese Patent Publication No. 220220/1987 shown in FIGS. To explain this structure, a chord portion at a position facing each other is partially cut out to punch out and form a reinforcing ring a2 having an outer diameter, and then a seal portion 2 is formed thereon to obtain an oil seal having a chipped outer peripheral portion. ing. However, even in such a reinforcing ring a2 having an outer diameter chipped material having an improved material yield, material loss is observed in the central core portion or a part of the outer peripheral portion, and no remarkable improvement has been made. The fatal drawback is
At the time of elongation and contraction processing such as drawing, where distortion is easily generated, large distortion occurs due to the outer diameter chipping where the mass of the peripheral part is not formed uniformly, greatly reducing the contact accuracy of the seal part. It is expected that this will have a very bad effect on sealability and durability. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described drawbacks, and has as its object to provide an oil seal capable of dramatically increasing the material yield and obtaining a high-precision and strong fitting force.

[0005]

The present invention will be described with reference to the drawings. As shown in FIG. 5, the present invention relates to an oil seal which is attached to a rotating part which rotates relatively and seals the same, and has a reinforcing ring 1; 1. An oil seal comprising a reinforcing ring 1 provided with a sealing portion 2 made of an elastic body, wherein a plurality of divided ring-shaped objects a1 are stamped and formed from a plate material A as shown in FIG. Each is joined and integrated to obtain an annular reinforcing ring 1, and a sealing portion 2 is provided on the reinforcing ring 1.

In addition, in a method of manufacturing an oil seal comprising a reinforcing ring 1 and a seal portion 2, a plurality of divided ring-shaped objects a1 are punched from a plate material A as shown in FIG. In this manner, the respective joining portions are joined to form an integrated annular reinforcing ring 1, and a sealing portion 2 having a seal lip or the like is formed on the reinforcing ring 1.

[0007]

The present invention has the following functions with the above-described configuration. That is, according to the present invention, as shown in FIG. 1, a divided ring-shaped object a1 having a divided shape of small pieces is punched and formed from a sheet material A such as a thin plate or a band plate (in general, at the same time as punching, drawing is performed in the punching die. Then, the divided ring-shaped object a1 is formed into a ring shape using a fixing means such as welding or bonding and integrated to form a reinforcing ring 1 having high rigidity. Thereafter, the seal portion 2 having a desired shape is molded and fixed using a mold or the like to obtain an oil seal with high overall accuracy.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to carry out the present invention, as the arrangement combination for efficiently punching out the divided ring-shaped objects a1, in addition to the shapes facing each other in a zigzag shape as shown in FIG. In addition, various combinations such as reverse parallel arrangement are possible, and the present invention is not limited to the two-part shape shown in FIG. .

Next, as for the fixing means for integrating the divided ring-shaped members a1 into a ring shape, a welding method for melting and fixing the members to each other, and a member having a fixing force therebetween are integrated. There are many fixing means, such as a sandwich method, a fixing method of a fixing member using a fixing member such as a belt, a ring, and a scramble, or a crimping method of shaping an engaging portion to be hooked on each other and fixing it by caulking.

In order to form the seal portion 2 on the reinforcing ring 1 thus formed, the surface of the reinforcing ring 1 is trimmed, degreasing,
Sealing part 2 of desired shape without base treatment such as adhesive application
This is an integral molding method that is often used by putting it together with an elastic material into a mold in which is cut and vulcanized. Of course, the seal portion 2 made of a synthetic resin may be formed by selecting one of the generally known molding methods suitable for the shape.

[0011]

According to the present invention, since the divided ring-shaped object a1 can be efficiently punched and formed by shaping the small piece into a divided shape, a high yield can be obtained, and a higher yield can be obtained with the multiple divided shape. It becomes possible. In the drawing processing of the divided ring-shaped object a1, the reinforcing ring 1 having no distortion is obtained because the internal stress due to the drawing is absorbed and released because of the divided shape having no peripheral shape. The divided ring-shaped object a1 formed in this manner becomes a reinforcing ring 1 having high accuracy in outer diameter and inner diameter and flatness due to the divided shape. Good oil seal can be provided.

[0012]

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a process of implementing the present invention.

FIG. 3 is a plan view showing a conventional punched shape without using the present invention.

FIG. 4 is a sectional view showing a shape of a reinforcing ring formed according to FIG. 3;

FIG. 5 is a sectional view showing a general oil seal.

[0013]

[Explanation of symbols]

 Reference Signs List A plate material 1 reinforcing ring a1 split ring-shaped object 2 seal portion a2 outer diameter chipped reinforcing ring

Claims (2)

(57) [Claims] In an oil seal having a reinforcing ring and a sealing portion made of an elastic body provided on the reinforcing ring, a plurality of divided ring-shaped members are stamped and formed from a plate material, and each of them is joined and integrated. An oil seal characterized in that a ring-shaped reinforcing ring is obtained by providing a sealing portion on the reinforcing ring. 2. A method of manufacturing an oil seal having a reinforcing ring and forming a seal portion made of an elastic body on the reinforcing ring, wherein a plurality of divided ring-shaped members are stamped out of a plate material, and each of the members is joined. Integrated to form an annular reinforcing ring,
A method for manufacturing an oil seal, wherein a seal portion is formed on the reinforcing ring.