JPH07124970A - Manufacture of split seal - Google Patents

Abstract

PURPOSE:To eliminate the cutting after molding by a method wherein stringy rubber material, on at least one edge face of which substance for inhibiting the fusion of the rubber is applied, is placed in the cavity of a bottom mold under the condition that a ring is formed by bringing both edge faces into contact with each other, and, after that, the cavity is closed with a top mold for vulcanization molding. CONSTITUTION:The slit oil seal 1 concerned consists of metal reinforcing ring 2 and sealing part 3, which is vulcanizingly bonded with the metal reinforcing ring 2. The reinforcing ring 2 is diametrically bisected under the condition that one divided part 4 is formed broader, while the other divided part 5 is formed narrower. At the portion of the sealing part 3 corresponding to the middle of the narrow divided part 5, a joining part 6 is formed. Accordingly, by expanding the joining part 6, the split oil seal 1 can be radially installed onto a shaft. At that time, since the divided part 4 of the reinforcing ring 2 opposite to the joining part 6 is formed with wide width, the expansion at the joining part become easy and, at the same time, the deformation of the sealing part 3 at the divided part 4 becomes easy, preventing stress concentration from developing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a seal such as an oil seal, a dust seal, a molded packing, an O-ring, etc., and in particular, a structure in which at least one part of the seal is broken in order to easily attach / detach to / from a mating member. The present invention relates to a method for manufacturing a split mold seal.

[0002]

2. Description of the Related Art In these seals, for example, in the case of an oil seal, when the shaft is mounted on the shaft, there are obstacles or the like when the mounting part has a diameter smaller than the diameter on both sides of the shaft or before it is fitted into the mounting part. In this case, since it is impossible to slide the mounting portion to the mounting portion, a part of the seal is broken and the seal portion is expanded and fitted into the shaft. Such a special seal is called a split seal.

As an example of a conventional split seal, in the case of an oil seal, a rubber material is vulcanized and adhered to a split metal reinforcing ring to form an oil seal, and one of the reinforcing rings of the oil seal is split. What cut | disconnects the rubber part of a part to a radial direction, expanded the cut part larger than a shaft diameter, and attached it to a shaft is described in Japanese Utility Model Publication No. 40-30242.

[0004]

However, in the case of such a split type seal, since the rubber portion at a predetermined position is cut after the seal molding, not only skill is required for cutting, but also
There was a problem that it required equipment and man-hours for cutting.

The present invention is intended to solve such a conventional problem, and an object thereof is to provide a method for producing a split seal which does not require cutting after molding.

[0006]

In order to achieve the above object, the present invention provides a cord-shaped rubber material in which a substance for preventing fusion of rubber is attached to at least one end surface in a cavity of a lower mold. After placing both ends together in a ring shape,
The upper mold is closed and vulcanization molding is performed by a compression molding method.

According to the present invention, a reinforcing ring formed by splitting at least one place is placed in a cavity of a lower mold, and the string-shaped rubber material is placed on the reinforcing ring so that its mating surface is aligned with the divided portion of the reinforcing ring. It is designed to be placed.

[0008]

According to the present invention, therefore, the ring-shaped rubber material placed in the cavity of the lower mold has a mating surface on which a substance that prevents the fusion of the rubber material is attached, so that the upper mold is closed. Even when molded, the mating surfaces of the rubber material do not fuse, and the mating surfaces can be expanded.

Further, by molding the mating surface of the ring-shaped rubber material at the split position of the at least one reinforcing ring, the seal is expanded from the mating surface even if the seal has the reinforcing ring. It becomes possible to do.

[0010]

1 is a plan view of a split type oil seal showing an embodiment of the present invention. The split oil seal 1 includes a metal reinforcing ring 2 and a seal portion 3 vulcanized and bonded to the reinforcing ring 2. The reinforcing ring 2 is divided into two in the diameter direction, one division portion 4 is formed wide, and the other division portion 5 is formed narrow. A joint portion 6 is formed in the portion of the seal portion 3 corresponding to the center of the narrow division portion 5. Therefore, the split type oil seal 1 can be mounted in the radial direction on the shaft by expanding the joint portion 6. At this time, since the divided portion 4 of the reinforcing ring 2 on the opposite side of the joint portion 6 is formed wide, the joint portion 6 can be easily expanded and the seal portion 3 of the divided portion 4 can be easily deformed. Therefore, stress concentration can be avoided.

2A and 2B show a manufacturing process of the split type oil seal 1 described above. FIG. 2A is a plan view showing a state where a reinforcing ring and a rubber material are placed on a lower mold, and FIG. 2B is a sectional view of FIG. , (C)
FIG. 4 is a cross-sectional view of the lower mold with the upper mold closed. First, the reinforcing ring 2 divided into two is placed in the cavity 8 of the lower mold 7. A rubber material 9 in the form of a string, which will become the seal portion 3 after molding, is placed thereon in a ring shape. The string-shaped rubber material 9 has a predetermined rectangular cross section, and has a substance for preventing fusion of the rubber material on at least one end surface, for example, a release agent or paint, and in the case of the present embodiment, a silicone-based release agent. After applying and drying APOLIZE (trade name, Yamami Shoko Co., Ltd.), both end faces are aligned with the centers of the narrow divisions 5 of the reinforcing ring 2 and placed on the reinforcing ring 2. Then, the lower mold 7 and the upper mold 1
Set 0 and heat at a predetermined temperature for a certain time. As a result, the rubber material 9 melts and fills the cavity 8, and is vulcanized to adhere to the reinforcing ring 2. At this time, since the mating surface of the rubber material 9 is coated with a substance having a releasing property, fusion of the mating surfaces is prevented. Then, the upper die 10 is opened, the product is taken out from the cavity 8, and post-processing such as deburring is performed to obtain a final product as shown in FIG.

As described above, according to the above-described embodiment, the cord-shaped rubber material 9 having the release agent applied to at least one end face is placed on the reinforcing ring 2 divided into two in a ring shape, Since the mating surfaces of both end surfaces of the reinforcing ring 2 are positioned and centered on the center of the narrow split portion 5 of the reinforcing ring 2, the joint portion 6 is joined to the seal portion 3 corresponding to the center of the narrow split portion 5 of the reinforcing ring 2. It is possible to obtain a split oil seal 1 having the above, and it is possible to realize a split oil seal that does not require cutting after molding.

The above description of the embodiment is an example in which the reinforcing ring is divided into two parts, but the reinforcing ring may be divided into only one part. In that case, a mating surface of a string-shaped rubber material is formed at the center of the divided part. Position and compression mold.

The present invention is not limited to oil seals,
It can be applied to split seals such as dust seals, molded packings, and O-rings, and similar effects can be obtained.

[0015]

As is apparent from the above-described embodiments, the present invention provides a string-shaped rubber material having a substance for preventing the fusion of the rubber attached to at least one end face in the cavity of the lower mold. Since they are put together in a ring shape and compression molded, it is possible to obtain a product having a joint part in the seal part in the product after molding, and the cutting process after molding is unnecessary. Have an effect.

According to the present invention, a reinforcing ring having at least one divided portion is placed in the lower mold cavity, and a string-shaped rubber having at least one end face thereof a substance for preventing the fusion of the rubber is attached. The material is placed in a ring shape, and the mating surface is aligned with the split portion of the reinforcing ring for compression molding.Therefore, the molded product has a seal portion corresponding to the split portion of the reinforcing ring. You can get a product with a joint,
It has an effect that the cutting process after molding and the skill of cutting in accordance with the divided portion of the reinforcing ring, which have been conventionally required, are unnecessary.
Furthermore, since both surfaces of the joint are formed in a pair with irregular irregularities, there is no deviation in the joint, and there is an effect of preventing deterioration of the sealing property.

[Brief description of drawings]

FIG. 1 is a plan view showing a split oil seal according to an embodiment of the present invention.

FIG. 2 (a) is a plan view showing a step of manufacturing a split oil seal according to an embodiment of the present invention in which a reinforcing ring and a rubber material are placed on a lower mold. (B) Sectional drawing of (a). Sectional drawing of the state which closed the upper mold from the state of (c) and (b).

[Explanation of symbols]

 1 Split type oil seal 2 Reinforcement ring 3 Seal part 4, 5 Divided part 6 Joined part 7 Lower mold 8 Cavity 9 Rubber material 10 Upper mold

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B29L 31:26

Claims (2)

[Claims] 1. A method for manufacturing a split mold seal by a compression molding method, wherein a string-shaped rubber material having a substance for preventing fusion of rubber adhered to at least one end surface is formed in a cavity of a lower mold. After placing both ends together in a ring,
A method of manufacturing a split mold seal, characterized in that the upper mold is closed and vulcanization molding is performed. 2. A reinforcing ring formed by breaking at least one place is placed in a cavity of a lower mold, and a string-shaped rubber material is placed on the reinforcing ring so that the mating surfaces of both end faces thereof are aligned with the divided part of the reinforcing ring. The method for manufacturing a split seal according to claim 1, wherein the split seal is placed.