| 摘要 |
PURPOSE:To prevent seizure of a piston due to deformation of a skirt part, by a method wherein a piston pin boss part is coupled to a skirt part, formed only to a portion on which a thrust force is exerted, through a peripheral rib continuous to the outer peripheral surface of a boss part. CONSTITUTION:A piston is constituted such that a piston pin boss part 22, with which a piston is engaged, is engaged with a skirt part 24, being formed only to a portion on which a thrust force is exerted, in the vicinity of a piston pin, through a peripheral rib 26 continuous to the outer peripheral surface of the piston pin boss part. This causes a load, produced during expansion, to be transmitted to the skirt part 24 through the rib 26, resulting in the possibility to prevent the piston from seizure occasioned by local deformation of the skirt part. |
