2017 年 62 巻 3 号 p. 217-227
Precise calculation of sealing pressure profile around cylinder bore is essential for the multi-layer-steel(MLS) engine cylinder head gasket design. This paper describes 2D finite element analysis of MLS head gasket taking into consideration of rubber coating model in which coating is expressed by means of hyper-elastic model and measured frictional coefficient is used as contact boundary condition. Modeling of the rubber coating of MLS is a key of the simulation. Two typical head gasket structures, inner-shim type and grommet type, are examined in this paper. The calculation results showed good agreement with pressure-sensitive paper measurement of both types of the gasket. Same modeling methodology is applied to assess a restraining force of a head gasket against a displacement of cylinder bore wall of open-deck aluminum cylinder block. The result illustrates that head gasket restraining force differs in head gasket structure and has a peak according to cylinder inner pressure. The restraining force peak is caused by the change of contact condition, from stick area to slip of rubber coating. The modeling methodology described in this paper provides a powerful simulation tool for the cylinder head gasket and engine structure design.
