Development of Rubber Pre-coated Metal Gasket Materials 980068
The recent tendency for higher output and high-rotation-speed auto-engines brings an increasing possibility of firing pressure and heat distortion.
On the other hand, demands for reducing the consumption of fuel change the material of auto-engine from cast iron to aluminum die-cast. Therefore, the number of cases of engine structure deformation and bore distortion are increasing. As this reason, the new robust type of cylinder head gasket is required for this aluminum block gasoline engine.
However, conventional gaskets such as metal reinforced flexible graphite and metal clad non-asbestos millboard have difficulty in maintaining the sealing performance and in reducing the bore distortion. The rubber pre-coated metal gasket can obtain sufficient clamp load on the head gasket and maintain good sealing performance.
The rubber-coated metal gaskets include the FKM coated metal gasket, which is called an after-coat type. This after-coat type gasket has several drawbacks, such as swelling of rubber, the resulting blister due to contact with an anti-freezing fluid to cooling engine, and high cost due to use of FKM rubber compound.
Rubber pre-coated metal gasket material was developed for open-deck type aluminum block gasoline engines. In the past several years, these rubber pre-coated metal gaskets have being adopted for high output aluminum block gasoline engines.
This paper describes development of rubber pre-coated metal gasket materials, which can be manufactured by continuous coating of coiled substrates such as metals. These materials have an excellent resistance to an anti-freezing fluid and good sealing performance in engine head gaskets.