The present invention relates to a metallic gasket and, more particularly, to a metallic gasket for use at the junction between a cylinder head and a cylinder block of an internal combustion engine. The present invention is directed to providing a metallic gasket which prevents leakage of combustion gas, cooling water and lubricating oil or the like.
There are a variety of shapes for such metallic gaskets used at the junction between a cylinder head and a cylinder block of an internal combustion engine.
The principle structure is arranged in such a manner that a bead is provided for a base plate made of an elastic metallic plate. The bead is elastically deformed by tightening a bolt, and the elastic restoring force caused by elastically deformed bead provides the sealing effect required at the junction.
A metallic gasket such as that described above can be laminated gasket comprising a plurality of gasket sheets. For example, as disclosed in Japanese Publication No. 62-261761 submitted by the applicant of the present invention, a gasket can have a structure comprising a laminated body formed by disposing two subplates on two sides of a core provided with a bead, together with a stopper provided in the flat portion adjacent to a projection closer to the combustion chamber than the position at which the bead is provided.
However, the above-described type of gasket can break due to the difference in the coefficients of thermal expansion of the stopper which is formed by a thermal spray and the base plate on which the stopper is formed. This is because the stopper is installed at the edge of the combustion chamber, and the base plate and the subplate repeatedly move relative to one another.