| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a piston device by which amount of oil consumption can be efficiently reduced by smoothly changing the pressure force of a piston ring in accordance with change in temperature. <P>SOLUTION: A piston-ring set 300 comprises a pair of almost annular side-rails 316, 317, and an almost annular spacer expander 310. The spacer expander 310 includes a 1st member 311 which is almost annular to form the external peripheral surface, and a 2nd member 312 which is bonded to the 1st member, and almost annular to form the internal surface. A second material constituting the 2nd member has a coefficient of expansion higher than a 1st material constituting the 1st member. <P>COPYRIGHT: (C)2004,JPO</p> |
