PISTON FOR INTERNAL COMBUSTION ENGINE AND INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To reduce oil consumption at a combustion chamber by reducing oil gathering at a third land between a second ring groove and an oil ring groove while inhibiting an increase of piston weight. SOLUTION: An oil return hole 46 for releasing oil to the inside of a piston penetrating from the outside of a piston to the inside of the piston is provide at the third land 43 in such a manner that the oil return hole projects to the inside of the piston from a piston inner wall surface 62. Oil gathering on the third land part 43 flows out to a piston inside space 63 through the oil return hole 46 together with blow-by gas during combustion operation in which the engine generates power. Oil adhering on the piston inner wall surface 62 is prevented from reversely flowing to the third land 43 through the oil return hole 46 when the engine scarcely generates power and gas in a crankcase reversely flows into the combustion chamber 13 through the oil return hole 46. COPYRIGHT: (C)2011,JPO&INPIT