PISTON OF INTERNAL COMBUSTION ENGINE AND COMBINATION OF PISTON WITH PISTON RING OF INTERNAL COMBUSTION ENGINE

摘要

[PROBLEMS] To provide a piston of an internal combustion engine and a combination of the piston with three piston rings comprising two pressure rings and one oil ring of the internal combustion engine capable of sufficiently suppressing the consumed amount of a lubricating oil when a combustion chamber is brought into a negative pressure in the intake stroke of the engine and when an engine brake is used. [MEANS FOR SOLVING PROBLEMS] In this piston of the internal combustion engine, a through hole communicating with the internal space of the piston is formed in an oil ring groove to which the oil ring is fitted, and a hole related to a second ring groove is opened in the bottom part of the second ring groove so as to ride over the lower surface of the ring groove from the vertical lower side of the piston to form it as a through hole linearly communicating with the internal space of the piton. In this combination of the piston with the three piston rings of the internal combustion engine, the piston is combined with the pressure rings having closed gaps within a specified range.