PISTON OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To effectively reduce the sliding friction loss using the dynamic pressure caused by oil film, in a reciprocating piston of an internal combustion engine.SOLUTION: A piston 10 includes: a cylindrical piston head 11 that is provided in a cylinder 1 in a slidable manner and of which top surface 11a defines a combustion space S; a pair of pin support walls (12L and 12R) provided below the piston head 11 integrally with the piston head 11 and supporting a piston pin 2; and a pair of skirts 13F and 13R connecting the pair of pin support walls and slidingly contacts with an inner wall of the cylinder 1. On at least one of outside surfaces 13aF and 13aB of the pair of skirts 13F and 13R, at least one of V-shaped groove 21 opening upward is formed, and the V-shaped groove 21 is arranged only on the downside of an axis 2X of the piston pin 2 in a direction of an axis 10X of the piston 10.