Internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorManabu TATENO
Life of this patent
Estimating the term…
Abstract
A thermal insulation film is formed on a bottom surface of a cylinder head facing a top surface of a piston. The thermal insulation film in a region (a circumferential region) of a bottom surface of the cylinder head configuring a squish area in a circumferential edge of a cavity region is formed to be thinner than the thermal insulation film in a region (a cavity region) of the bottom surface of the cylinder head facing a cavity. The thermal insulation film in the circumferential region is polished, and surface roughness thereof is equal to or lower than 3 μm. The thermal insulation film in the cavity region is not polished, and surface roughness thereof is 3 to 8 μm on average.
Claims5
An internal combustion engine including a top surface of a piston, on which a cavity is formed, and a bottom surface of a cylinder head that configures a combustion chamber together with the top surface, and has a thermal insulation film, which has a lower thermal conductivity and a lower thermal capacity per unit volume than a base material, formed thereon,
- wherein in the bottom surface of the cylinder head which configures the combustion chamber, surface roughness of the thermal insulation film in a circumferential region that configures a squish area in a circumferential edge of a cavity region is formed to be smaller than surface roughness of the thermal insulation film in the cavity region facing the cavity.
Dependencies are inferred from the claim text.