| 摘要 |
PURPOSE:To lighten the weight of a piston while keeping merits of a cast iron piston by forming a piston body out of cast iron, and fixedly securing a piston skirt cylindrically formed out of SEP (super engineering plastic) on the lower edge of a piston head. CONSTITUTION:On the underside of a piston head 8, a piston body 11 provided with boss parts 10 in which a piston pin connecting to a connecting rod 9 can be inserted, is formed out of cast iron. On the lower edge of this piston head 8 and the lower end of the boss part 10, supporting parts 12, 13 extending in the circumferential direction are formed in one body with the piston body 11. A pair of two gutter-like members 14 in the shape of a cylinder extended in the vertical direction and divided in the axial direction are formed out of SEP (super engineering plastic) having heat resistance property. The upper and lower end faces and the upper and lower edge parts of inner surface of respective gutter-like members 14 are fixedly secured to the supporting parts 12, 13, the divided surfaces extending in the vertical direction of respective gutter-like members 14 are also fixedly secured each other, and a cylindrical piston skirt 15 extending downward is formed on the lower edge of the piston head 8. |
