JPS6030324A - Manufacture of gasket - Google Patents

Abstract

PURPOSE:To shorten mold-making time significantly and eliminate the possibilities of damage on a mold by compressing a material with members such as a female force engraved in a desired shape and an elastomer plate in the forming of an uneven surface such as bead strip on a gasket. CONSTITUTION:A gasket material 1 is sandwiched between a female force A having a recess 3 and an elastomer plate C mounted on a plate 4 beforehand, and thus is compressed between these two members A and C (female force A and plate 4). The gasket material 1 is easily deformed to the shape of the recess 3 in the female force A, thus forming a recessed part 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a gasket used for a cylinder head of an internal combustion engine, and more specifically to a method of providing an uneven portion such as a bead on the gasket.

Conventionally, protruding portions such as protruding stripes or protruding rings provided on gaskets have been formed into various shapes because the protruding portions receive local surface pressure when compressing the gasket, resulting in good sealing performance.

In general, to mold this convex part, as shown in FIG. A method is used in which a gasket material 1 is sandwiched between B and B and compression is applied to form protrusions 2 on the surface of the gasket material 1 as shown in Fig. 2.This is the only method in which the gasket material has sufficient hardness and rigidity. It was believed that it was impossible to form the protrusion 2 on the 1. However, in this method, since the female and male molds A and B are made of co-metallic metals, minor factors such as poor matching can easily cause scratches and dents, which increases the risk of damage. The female mold A, which is concave and recessed, can be easily carved and the mold cost is within an acceptable range, but the male mold B, which protrudes, has an inevitable shape that makes it expensive. Since the male mold B has the above-mentioned convex shape, it takes a lot of time and effort to form that shape, and it is also troublesome to align the two, so the female mold B and the male mold B are combined into one set. The molds were very expensive and had many drawbacks, such as having a strong impact on product costs.

The present invention has been made to eliminate these drawbacks, and provides a method for manufacturing a gasket that enables mold production at low cost and in a short time, and that does not cause damage when handling the mold. .

As shown in FIG. 6, the present invention is a gasket in which a protrusion 2 such as a bead is formed on a gasket material 1 based on a metal plate such as a metal plate, a rubber coated metal plate, or a rubber asbestos crimped metal plate. The protrusion 2 is formed by inserting the gasket material between the two members A and 0, which are a female mold engraved with a desired shape and an elastic flat plate 0 having an appropriate hardness such as synthetic rubber. It is obtained by clamping 1 and then compressing it.

This gasket manufacturing method effectively utilizes the characteristics of the elastic body, such as flexibility, repulsion, and lateral flow, and allows the gasket to function similarly to the male mold B. That is, as shown in FIG. 3, a female mold A having a concave portion 3 and an elastic main flat plate C previously placed on a flat plate 4 are used to inject a gasket material 1 between the two members A-0.
The female mold A and the flat plate 4 are compressed as shown in FIG.

At this time, the surface compression receiving surface of the elastic flat plate O tends to be pushed back by the repulsive force generated from inside the elastic flat plate 0, and directs a strong repulsive force to the gasket material 1. Due to this repulsive force, the gasket material 1 comes into pressure contact with the female mold A having the four parts 6 located on the upper part of the gasket material 1, and receives this pressure. However, the gasket material 1 deforms only that part and tries to flow in, concentrating the repulsive force, so even if the gasket material 1 has sufficient hardness and rigidity, it easily deforms according to the shape of the four parts 3 of the female mold A. A convex portion 2 is formed. Since the gasket material 1, which has once been deformed in this way, is constructed based on a metal plate, it does not recover its shape even after being released from the compression, and maintains the desired shape of the female mold 3-A. This becomes the protruding portion 2.

Note that the protruding portion 2 formed on the gasket material 1 can have various shapes such as its shape and depth, but it can be handled optimally by selecting the optimal hardness, plate thickness, or contact area of the elastic flat plate 0. shape can be obtained.

In addition, since the elastic plate 0 is preferably a flat plate and has a simple shape, the cost can be greatly reduced.

As explained above, the present invention has been developed using an expensive male mold of a pair of molds, a female mold and a male mold, which have conventionally been required to form bead lines etc. protruding on the surface of a gas nut. This is an innovative method that allows the desired shape to be obtained by replacing the mold with an incomparably low-cost elastic plate.It is an ideal method that greatly reduces mold production time and eliminates the risk of mold damage during work. This is a typical gasket manufacturing method.

[Brief explanation of the drawing]

14= FIG. 1 is a sectional view showing a conventional gasket manufacturing method. FIG. 2 is a partially cutaway perspective view of a gasket with a protrusion formed thereon. FIGS. 6 and 4 are cross-sectional views showing the process of forming a protrusion on the gasket of the present invention. A: Female mold B: Male mold 0: Elastic body flat plate 1: Gasket material 2: Convex portion 6: Concave portion 4: Flat plate Patent applicant Uchiyama Kogyo Co., Ltd. company

Claims (1)

[Claims] In a gasket manufacturing method in which a convex protrusion such as a bead strip is formed on a gasket material based on a metal plate such as a metal plate/rubber coating metal plate ° rubber asbestos crimped metal plate; the protrusion has a desired shape. A method for manufacturing a gasket, which comprises compressing the gasket material with two members: a carved female mold and a flat plate of elastic material having appropriate hardness such as synthetic rubber to form a desired bead line, etc.