PISTON FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To effectively supply lubricant to a relief groove 22 recessed on a bearing surface 14 and to reduce the weight of a pin boss part 15. SOLUTION: The pin boss part 15 integrally ties a piston head 11 including a piston crown surface 12 with an approximately cylindrical part 13 formed with the bearing surface 14 for inserting a piston pin. The relief groove 22 recessed on the bearing surface 14 along the peripheral surface of the piston pin is arranged within an upper half area R of the piston crown surface 12 in the bearing surface 14. Prolongations 24 along thrust side edges 23a of the pin boss 15 are made to intersect with the relief groove 22 in an axial view of the piston pin. COPYRIGHT: (C)2003,JPO