IN-CYLINDER FUEL-INJECTION TYPE INTERNAL COMBUSTION ENGINE, PISTON FOR IN-CYLINDER FUEL-INJECTION TYPE INTERNAL COMBUSTION ENGINE AND PROCESS FOR MANUFACTURING PISTON FOR IN-CYLINDER FUEL-INJECTION TYPE INTERNAL COMBUSTION ENGINE

摘要

A piston for in-cylinder fuel-injection type internal combustion engine includes a piston body, a low thermal conductor, and a piston head. The low thermal conductor is disposed on the top of the piston body. The low thermal conductor includes a low thermally-conductive substrate, and a coating layer. The low thermally-conductive substrate has opposite surfaces. The coating layer includes alumina fine particles (Al₂O₃). The coating layer is adhered on at least a part one of the opposite surfaces of the low thermally-conductive substrate that makes a cast-buried or enveloped surface to be cast buried or enveloped in the piston head.