JP2000320678A - Gasket and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasket to which an elastic seal part consisting mainly of a metallic sheet is added and which effectively provides respective material characteristics, and improves moldability and sealing performance. SOLUTION: A gasket comprises a metallic sheet-form gasket body 1, and a seal part 4 made of an elastic substance. A thin section part la is formed at the peripheral edge of the opening part of the gasket body 1 and an annular groove 1b is formed in the vicinity thereof. The seal part 4 is formed as a surplus material absorbing space for the elastic substance during molding. This constitution shields and partitions an elastic material being about to disperse on the plane of the gasket body 1 during molding and provides strong sealing action.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gasket mainly made of metal, and more particularly to a gasket for an engine mounted on an automobile or the like, the gasket comprising a metal plate for sealing the two members between the constituent members and an elastic seal portion. And its manufacturing method.

[0002]

2. Description of the Related Art Conventionally, a gasket for an engine of an automobile or the like is an important part which is mounted between members of a flange through which a bore hole, a water hole, an oil hole and the like passes to seal the two members. As a constituent material, there are many cases in which a metal plate having excellent torque holding force and an elastic seal material made of rubber or the like capable of obtaining a stable surface pressure are combined and integrally formed. As an example of a gasket having such a combination structure of a metal plate and an elastic sealing material, a structure is provided in which a mounting portion is provided on the periphery of an opening portion of a gasket main body having a constant thickness, and the elastic gasket is disposed on the mounting portion. It is widely known that a metal plate gasket body is expected to achieve strong sealing by surface compression, and an elastic gasket is used to obtain highly flexible local surface pressure and provide optimal sealing force at each location. In this way, we expect a comprehensive high sealing effect.

[0003]

However, the gasket structure in which the elastic gasket is disposed around the opening of the gasket main body made of a metal plate as described above has a portion that cannot exhibit the performance matching the characteristics of each material. There is a possibility of having many, and unevenness in sealing performance is apt to occur. That is,
In the molding of the gasket, as shown in FIG. 3 described with reference to the drawings, an elastic material is filled into the cavity around the opening of the gasket main body 1 in the molding die 3 and compression molded together with the gasket main body 1. Excess material other than the cavity volume of the elastic gasket 2 overflows in both directions of the inner and outer peripheral portions and flows out. Even if the surplus material receiving groove 3a can be formed on the inner peripheral side portion on the split surface of the molding die 3, There is no effective material escape space on the outer peripheral portion (gasket main body 1 side). Therefore, the outer peripheral portion of the elastic gasket 2 extends from the periphery of the opening as shown in FIG. The thin film 2a extending to the flat surface portion is formed.

[0004] In this case, the gasket thus formed has a surface pressure distribution due to the compression of the gasket main body 1 at the time of mounting, which varies depending on the portion, due to the thin film 2a, and the uniformity of the sealing surface is greatly impaired. Of course, the diffusion of the thin film 2a has an adverse effect on the elastic gasket 2, and the local surface pressure range of the elastic gasket 2 is uncertain, and as a result, the sealing action may be weakened. The present invention has been made in view of such a drawback, and an object of the present invention is to provide a gasket in which the material properties of the respective materials are effectively exhibited, and the moldability and the overall sealing performance are enhanced.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, between a mounting member of a cylinder head or an intake / exhaust member of an automobile engine and a cylinder block or the like. 1. A gasket comprising a metal plate-shaped gasket main body 1 to be mounted and a seal portion 4 made of an elastic body. As shown in FIG. 1, the gasket main body 1 has a peripheral edge of an opening such as a bore hole or a water hole. A thin portion 1a having a step is provided, and an annular groove 1b surrounding the thin portion 1a is formed slightly apart from the thin portion 1a toward the main body, and a seal portion 4 is press-formed on the thin portion 1a. It is characterized by that.

A gasket manufacturing method in which a plate-shaped gasket main body 1 made of metal and a seal portion 4 made of an elastic body are combined, as shown in FIG. A stepped thin portion 1a is formed around the periphery of the opening, and an annular groove 1b is cut in the plane of the gasket main body 1 slightly apart from the thin portion 1a. An elastic material such as synthetic rubber or synthetic resin is supplied to the thin portion 1a of the gasket body 1 slightly more than the cavity volume, and the annular groove 1b is formed as an overflow absorbing space of the excess elastic material to form a seal portion 4. It is characterized by:

[0007]

According to the present invention, as described above, the annular groove 1b is provided in the vicinity of the opening of the gasket main body 1 having the thin portion 1a so as to surround the opening. As an overflow absorption space of the surplus elastic material, the elastic material which is to diffuse on the plane of the gasket main body 1 is blocked by the annular groove 1b as shown in FIG. Seal part 4
(Elastic material) works to make a clear line.

In the molding of the gasket, as shown in FIG. 1, the elastic material charged on the thin portion 1a of the gasket main body 1 in the molding die 3 fills the cavity when receiving the clamping pressure, and its volume is increased. The elastic material supplied in a slightly larger amount becomes surplus material and overflows to the inner and outer peripheral surfaces. The surplus elastic material that flows out is provided on the inner peripheral side with a surplus material engraved on the molding die 3. The groove 3a absorbs this correspondingly, and the annular groove 1b provided in the flat portion of the gasket main body 1 on the outer peripheral side serves as a surplus receiving space, which serves to receive it and prevent further diffusion. Here, the seal portion 4 of the gasket main body 1 is clearly separated by the annular groove 1b in the plane portion, and the plate-shaped metal portion of the gasket main body 1 and the elastic portion of the seal portion 4 are flat as shown in FIG. Will be clearly defined.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In forming a gasket according to the present invention, when forming a gasket body 1 from a metal plate, an annular groove 1b is formed in a plane portion thereof in advance, and a thin portion 1 is formed on the periphery of the opening.
a is formed by rolling or cutting, and the gasket main body 1 and the elastic material are put into a molding die 3 and compression-molded. Slightly larger than volume (100.1% ~
The excess material overflows as shown in FIG. 1 and is received by the excess material receiving groove 3a of the inner peripheral portion and the annular groove 1b of the gasket main body 1 as shown in FIG. 1, and the excess material here is also fixed. Let it be molded. After this molding, the excess material that has been removed from the mold 3 and has become burrs is removed (annular groove 1b).
The surplus material in the above does not remain a problem even if it is not dared to be removed due to the state of accumulation in the recess. ) A gasket is formed.

The portion between the annular groove 1b and the thin portion 1a is formed in a ring shape protruding from the low surface portions on both sides.
In the compression, the space exerts a local surface pressure different from that of the flat portion.

The annular groove 1b provided on the gasket main body 1 of the present invention may be arranged in a plurality of rings having different diameters, when the annular grooves 1b are provided on the upper and lower surfaces, they may be arranged in a staggered manner, or may be formed in a meandering shape. Non-circular shapes can also be adopted, and semi-circular, triangular,
Various groove shapes such as a square, a polygon, and a combination thereof can be selected.

[0012]

According to the present invention, the annular groove 1b is provided in the vicinity of the opening of the gasket main body 1 so as to surround the opening. A clear compartment can be made by blocking the elastic material that is about to diffuse upwards.
With such a clear section, the gasket main body 1 made of a metal plate and the seal portion 4 made of an elastic body exhibit respective material characteristics, and form a uniform sealing surface in which the surface pressure distribution does not change due to compression. Since a good surface pressure is maintained, a strong sealing action is achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a molding state of the present invention. (Figure 2
A-A 'cross section is shown. )

FIG. 2 is a partial plan view showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional molding example without using the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gasket main body 1a Thin part 1b Annular groove 2 Elastic gasket 2a Thin film 3 Mold 3a Excess material receiving groove 4 Seal part

Claims (2)

[Claims] 1. A plate-like gasket main body made of metal,
In a gasket in which a seal portion made of an elastic body is combined, the periphery of an opening such as a bore hole or a water hole in the gasket main body is formed into a stepped thin portion, and is slightly separated from the thin portion toward the main body. A gasket, wherein an annular groove surrounding the thin portion is formed, and a seal portion is disposed in the thin portion. 2. A plate-shaped gasket main body made of metal,
In a method of manufacturing a gasket in which a seal portion made of an elastic body is combined, a thin portion having a step is formed around the periphery of an opening such as a bore hole or a water hole of a gasket main body, and is slightly separated from the thin portion toward the main body. Then, an annular groove surrounding the thin portion is engraved, an elastic material is supplied to the thin portion of the gasket main body in a molding die, and the seal portion is press-formed by using the annular groove as a storage space for excess material. A method for producing a gasket, comprising: