| 摘要 |
PURPOSE:To prevent effectively a knock pin from dropping out of a piston in high temperature by making the knock pin of austenite system stainless steel which prevents a piston righ fitted in the aluminum alloy piston from turning. CONSTITUTION:An aluminum alloy piston 1 is formed on the outer peripheral surface with an annular groove 3 in which a knock pin hole 5 is radially formed in the form of a blind hole. A knock pin 2 of austenite system stainless steel is fitted into this pin hole 5 with an interference delta. The piston ring 4 is formed on the back corners of a slit 4b with arcuate notches 4a. And the piston ring 4 is fitted in the annular groove 3 with the notches 4a being aligned with the knock pin 2. Thus, since the difference of expansion coefficient between the knock pin 2 and the piston 1 can be maintained small, the interference delta remains even in high temperature of the piston 1 to prevent the pin 2 form dropping out. |
