Piston for internal combustion engine

摘要

A piston 5 has a projection 16 formed on an end surface 5a, positioned near an intake port disposed on one side of the upper surface of a combustion chamber. A cavity 17 is formed at a position closer to an exhaust port than projection 16, with an ignition point of a spark plug disposed above cavity 17. The intake port points toward the outer perimeter of the combustion chamber. The portion of projection 16 on piston end surface 5a that faces the intake port is cut away. An intake flow passage 19 is partially defined by end surface 5a of piston 5, extending from cut-away section 18 toward the exhaust port via the outer perimeter of piston end surface 5a. The end of intake flow passage 19 toward the exhaust port forms a cavity entry 20 through which intake air flows into the cavity 17. The intake air entering the combustion chamber from the intake port goes through cut-away section 18 of projection 16, through the outer perimeter portion of piston end surface 5a, and into cavity 17 from entry 20 toward the exhaust port. A swirling effect is formed in cavity 17. <IMAGE>