| 摘要 |
PCT No. PCT/FR79/00029 Sec. 371 Date Nov. 30, 1979 Sec. 102(e) Date Nov. 30, 1979 PCT Filed Mar. 30, 1979 PCT Pub. No. WO79/00862 PCT Pub. Date Nov. 1, 1979.Internal combustion engine piston of the composite type, having a steel upper portion surmounting an aluminum lower portion in which the piston ring grooves are provided. The lower portion (2) comprises a concentric circular cavity (3), open at the top and recessed from the ring grooves (5), said cavity being covered by an annular groove (7) in the lower surface of the steel upper portion (1) to form a dead space. |
