| 摘要 |
PURPOSE:To prevent deteriorating of working oil in a device, in which a subpiston is fitted to a subcylinder communicated to a combustion chamber and slidably controlled by supplying pressure oil to a back side of said subpiston, by providing a blow-bye gas chamber to the internal periphery of the subcylinder. CONSTITUTION:A subpiston 9 is fitted to a subcylinder 7 communicated to a combustion chamber 5, and a pressure oil chamber 12 is provided to the back side of said subpiston 9, then pressure oil is supplied through a check valve 13, while a spill ring 17 changing a discharge amount of working oil from a spill port 16 is driven by a driving gear 25, and a position of the subpiston 9, that is, compression ratio is controlled. An annlar blow-bye gas chamber surrounding the subpiston 9 is provided to the internal periphery of said subcylinder 7 and communicated to a blow-bye gas processing part 22 through a through hole 20 and a passage 21. In this way, mixing of blow-bye gas in the chamber 12 is suppressed, and deterioration of the working oil can be prevented. |
