JPH0223385Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a mold used for molding an oil seal formed by baking an elastic seal piece made of a rubber-like elastic material to the radial end of a reinforcing ring. The present invention proposes a structure for an oil seal mold that can improve the stability of adhesion between the ring and the elastic seal piece, thereby stably extending the life of the oil seal.

As shown in Fig. 1, an elastic seal piece 2 made of an elastic material such as a rubber material is baked onto one radial end of a reinforcing ring 1 to produce an oil seal. As an example of a mold, a mold for oil seals as shown in Fig.
It is disclosed in Publication No. 23682. In the oil seal molding die shown in the figure, one of the molding dies 5 is assembled with each other in order to mold the elastic seal piece 2.
A main cavity 10 formed between the main cavity 10 and the other mold 6 is provided adjacent to the main cavity 10 in the one mold 5 and the other mold 6, and has an annular shape in pressure contact with the surface of the reinforcing ring 1. Since the main cavity 10 is partitioned by the projecting edges 11 and 12, a sealed cavity is formed on each annular projecting edge 11 and 12 side of the main cavity 10, so that no adhesion to the mold surface occurs. The generated scum, foreign matter mixed in the mold release agent sprayed on the mold surface, gas generated in the main cavity, etc. tend to collect in the closed cavity of the clogging, and this becomes the core of the release after vulcanization molding. There is a risk that the adhesive between the elastic sealing piece and the reinforcing ring may peel off due to external force during molding or assembly into a device.

The purpose of the present invention is to solve the problems with the conventional oil seal molds described above.The present invention is an annular ridge that presses against the surface of a reinforcing ring and partitions a main cavity for molding an elastic seal part. A small annular groove that cooperates with the reinforcing ring to form a sub-cavity is provided adjacent to the reinforcing ring, and a micro-groove that communicates the main cavity and the sub-cavity is provided on the dividing surface of the mold, so that the microscopic grooves that flow into the annular flange side are provided. By allowing the elastic material mixed with foreign matter to flow out to the sub-cavity side through the micro grooves, a configuration is created in which minute foreign matter does not remain within the elastic seal piece, and the adhesive between the elastic seal piece and the reinforcing ring is strengthened. It is something.

The fine grooves that communicate the main cavity and the sub-cavity are formed in a radial shape, a lattice made of radial grooves and circumferential grooves, or a lattice made of diagonally extending fine grooves that intersect with each other.

According to the oil seal mold having the above structure, when pressurizing the elastic material to form the elastic seal piece, the part at the tip of the material flow where minute foreign matter adheres is annular. Since it is discharged to the sub-cavity side through the fine groove provided between the projecting edge and the annular groove for the sub-cavity, there are no minute foreign substances remaining on the molded elastic seal piece, and as a result, the seal piece and reinforcement The adhesion of the ring is strongly maintained. If the surface roughness of the mold dividing surface that spreads from the annular groove forming the sub-cavity to the side opposite to the main cavity side is set to a large value, the flow of air and gas that is pushed by the molding material of the elastic seal part and excluded from the main cavity will occur. Since this is carried out smoothly, the outflow of the above-mentioned minute foreign matter adhering material is facilitated, which is advantageous.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows a mold for molding the oil seal shown in FIG. 1, and is provided in one mold 5 at the top and bottom of the figure and the other mold 6 at the top of the figure, respectively.
Annular ridge 1 separating main mold cavity 10
Annular small grooves 14 and 15 are cut in the vicinity of the reinforcement rings 1 and 12, and cooperate with the surface of the reinforcing ring 1 to form the sub-cavity 1.
6 and 17, and a fine groove 19 whose details are illustrated in FIG. The outer dividing surface 10 is formed to have a coarse surface roughness.

FIG. 4 is a partial plan view showing an example of the shape of the fine grooves 19 provided for communicating the main cavity 10 and the sub-cavity 15 shown in FIG. Figures b and c show examples in which grids are formed.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view showing an example of the structure of an oil seal to be molded by the oil seal mold according to the present invention, and FIG. 2 is a half-sectional view showing an example of the structure of an oil seal mold according to the prior art. Figure 3 is a half-sectional view showing an embodiment of the oil seal mold of the present invention;
FIG. 4 is a partial plan view showing an embodiment of fine grooves that communicate the main cavity and the sub cavity. 1... Reinforcement ring, 2... Elastic seal piece, 5...
One mold, 6... The other mold, 10... Main cavity, 11, 12... Annular flange, 14, 1
5... Annular small groove, 16, 17... Sub cavity,
19... Fine groove, 20... Molding mold dividing surface.

Claims (1)

[Claims for Utility Model Registration] 1. In a mold used for manufacturing an oil seal in which an elastic seal piece 2 is bonded to the radial end of a reinforcing ring 1, the elastic seal piece 2 is pressed against the reinforcing ring 1 and Near the annular projections 11 and 12 that partition the main cavity 10 for molding the seal piece 2,
Sub-cavities 16 and 17 are provided between the reinforcing ring 1 and the reinforcing ring 1.
A mold for an oil seal, which is provided with annular small grooves 14 and 15 that form the main cavity 10 and the sub cavities 16 and 17. 2 Main cavity 10 and sub cavities 16, 17
The mold for an oil seal according to claim 1, wherein fine grooves 19 communicating with each other are formed radially. 3 Main cavity 10 and sub cavities 16, 17
The mold for an oil seal according to claim 1, wherein the fine grooves 19 communicating with each other are formed in a lattice pattern. 4 From the annular small grooves 14 and 15 to the main cavity 10
The oil seal mold according to claim 1, wherein the mold dividing surface 20, which extends in the opposite direction, is formed into a rough surface.