PISTON OF DIRECT INJECTION TYPE INTERNAL COMBUSTION ENGINE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To favorably promote evaporation of ejected fuel even when an engine is operated under cold environment. SOLUTION: A fuel injection valve 13 ejects fuel toward a dished part 21 concavely formed in the top face of a piston 20. A low heat transfer member 22 formed of a titanium alloy sintered material is arranged on the bottom and side surfaces of the dished part 21 to which fuel is sprayed. Pores having an appropriate ratio are formed in the inside of the low heat transfer member 22 by the adjustment of a compressive load when the sintered material is pressurized and molded, and the heat insulation properties of the low heat transfer member 22 are controlled through these pores.