JPS62261759A - Metal gasket - Google Patents

Abstract

PURPOSE:To improve a sealing property as well as reliability by providing an elastic member in a space part which is formed in the height direction of a bead when forming said bead on a base plate. CONSTITUTION:When a metal gasket 2 is compressed and deformed by a bolt clamping force, a bead 10 is prevented from becoming flat due to an elastic member 14 in a space part 12. Also, the spring constant of the bead is made larger to prevent the permanent set of the bead and prevent the deterioration in its function. Further, the bead and the elastic member can combinedly give a defined sealing face pressure to a deck face. Thereby, a sealing property as well as reliability can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to metal gaskets, and in particular, the spring constant is increased to prevent functional deterioration of the bead, and a predetermined sealing surface pressure is applied to the deck surface to seal the gasket. In order to improve sexual
Regarding metal gaskets with high reliability.

[Conventional technology]

A metal gasket is used at the joint between a cylinder head and a cylinder block that constitute an internal combustion engine. The metal gasket has a bead formed to seal the deck surface between the cylinder head and the cylinder block, and this bead causes an elastic force to be applied to the deck surface by the fastening force of a fastening means such as a bolt that joins the members to be joined. It forms a seal line and performs a seal. As a metal gasket,
For example, it is disclosed in Japanese Utility Model Application No. 12653/1983 and Japanese Patent Application No. 111046/1982 by the present applicant. The metal gasket of Utility Model Application No. 60-12653 is
In order to prevent bead breakage, the inner bead surrounding the cylinder bore and the outer bead including the hole bead are configured not to come into contact with each other. Also, patent application No. 58-111046
The metal gasket of the publication expands the surrounding surface area of the bead formed around the cooling water hole to form a cooling water circulation gap,
This provides a cooling water effect. The metal gaskets described in each of the above-mentioned publications have a convex bead surrounding the cylinder bore.

[Means for solving problems]

By the way, in conventional metal gaskets in which a convex bead is formed, when the bead is compressed and deformed during fastening, the bead becomes substantially flat. If the area around the combustion chamber expands or contracts due to the influence of combustion gas or engine heat, the bead will become sagging due to the alternating load, leading to functional deterioration of the bead and causing a predetermined sealing surface pressure to be applied to the deck surface. This made it difficult to seal, resulting in a decrease in sealing performance and a lack of reliability.

[Purpose of the invention]

Therefore, an object of the present invention is to eliminate the above-mentioned disadvantages, and by disposing an elastic member in a space formed in the bead height direction by forming a bead on a substrate, the bead becomes flat due to the fastening force. In addition, the spring constant of the bead is increased to prevent functional deterioration of the bead, extending its service life, and applying a predetermined sealing surface pressure to the deck surface to improve sealing performance and improve reliability. The goal is to create a metal gasket that can increase the cost.

Means for Solving the CrJIa Point] To achieve this object, the present invention provides a metal gasket that achieves sealing by forming a combustion chamber hole and a bead surrounding the combustion chamber hole in a substrate made of an elastic metal plate. The present invention is characterized in that an elastic member is disposed in a space formed in the bead height direction by forming the bead on the substrate.

[Effect]

According to the configuration of the present invention, when the metal gasket is compressively deformed by the bolt fastening force, the elastic member in the space prevents the bead from becoming flattened, and the spring constant of the bead is increased, so that the bead In addition to avoiding sagging and preventing functional deterioration, the bead and elastic member overlap to apply a predetermined sealing surface pressure to the deck surface, thereby improving sealing performance and reliability. Make it expensive.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

1 to 3 show embodiments of this invention. In the figure, 2 is a metal gasket, and this metal gasket 2 is constituted by a substrate 4 made of an elastic metal plate. A combustion chamber hole 6 is formed in this substrate 4, and
A plurality of bolt holes 8 are formed around this combustion chamber hole 6. Furthermore, a bead 10 surrounding the combustion chamber hole 6 is formed on the substrate 4 .

This bead 10 is formed in a convex shape, so that a space 12 is formed in the height direction of the bead 10.

As a result, when the metal gasket 2 is interposed and fastened to the joint portion 22 described later, the top portion 10a and the base portions 10b, 10b of the bead 10 apply sealing surface pressure to the deck surface,
It serves as a seal.

In the space 12, an elastic member 14 made of rubber, synthetic resin, etc.
to be placed. In other words, bead part 1 of metal gasket 2
6 is constituted by an elastically deformable bead 10 and an elastic member 14 overlapping each other.

Further, in FIG. 3, reference numeral 18.20 indicates a cylinder head and a cylinder block constituting an internal combustion engine, and a metal gasket 2 of the present invention is inserted between the joint 22 between the deck surface of the cylinder head 18 and the cylinder block 20. equipped,
It is fastened with a fastening bolt (not shown). In addition, code 2
4 is a combustion chamber, and 26 is a piston.

Hereinafter, the operation of the embodiment of this invention will be explained.

The metal gasket 2 interposed in the joint 22 between the cylinder head 18 and the cylinder block 20 is compressed by the bolt fastening force, thereby compressing and deforming the bead 10 of the substrate 4 by reducing its height.

At this time, as shown in FIG. 3, the elastic member 14 provided within the space 12 is elastically deformed. Therefore, at the bead portion 16, the spring constant is increased due to the elastic deformation of the bead 10 and the elastic member 14, and the cylinder head 18
A strong sealing surface pressure can be applied to the deck surface between the cylinder block 20 and the cylinder block 20. Thereby, even if the area around the combustion chamber 24 expands or contracts due to the influence of combustion gas pressure or engine heat, leakage of combustion gas at the bead portion 16 can be reliably prevented. Furthermore, since the bead 10 is not flat, alternating loads that would otherwise act on the bead 10 are avoided, and the occurrence of sagging is prevented, thereby preventing functional deterioration of the bead 10. As a result, the service life of the metal gasket 2 is extended, sealing performance is improved, and reliability is increased.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made.

For example, in the embodiments described above, the elastic member is provided in the space of the convex bead, but it is also possible to provide the elastic member in the space formed by the stepped bead or other differently shaped beads.

〔Effect of the invention〕

As is clear from the above detailed description, according to the present invention,
By arranging an elastic member in the space formed in the bead height direction by forming a bead on the substrate, the bead can be prevented from becoming flat during fastening, and the bead's spring constant can be increased to prevent the bead from becoming flat. In addition to preventing functional deterioration and extending the service life, the bead and elastic member can polymerize and apply a predetermined sealing pressure to the deck surface, which greatly improves sealing performance and improves reliability. It can increase sex.

[Brief explanation of drawings]

1 to 3 show examples of the present invention. FIG. 1 is a plan view of a metal gasket, FIG. 2 is an enlarged sectional view of the main part taken along line nn in FIG. FIG. 2 is a partially omitted main part sectional view of a state in which a gasket is interposed in a joint of an internal combustion engine. In the figure, 2 is a metal gasket, 4 is a substrate, 6 is a combustion chamber hole, 10 is a bead of the substrate, 12 is a space, 14 is an elastic member, 16 is a bead portion, 22 is a joint, and 24 is a combustion chamber. be.

Claims (1)

[Claims] In a metal gasket that achieves sealing by forming a combustion chamber hole and a bead surrounding the combustion chamber hole in a substrate made of an elastic metal plate, a space is formed in the bead height direction by forming the bead in the substrate. A metal gasket characterized by having an elastic member disposed therein.