| 摘要 |
PURPOSE:To suppress knocking and improve an efficiency of an engine by lowering a compression ratio in an operation range of a miniture turbocharger, and increasing the compression ratio in the operation range of a large turbocharger. CONSTITUTION:At the time of closing an exhaust switching valve 38, supercharge is performed by a small turbocharger 18. At the opening of the valve 38, the supercharge is performed by a large turbocharger 17. At the time of operating of the small turbocharger 18, the compression ratio of an internal combustion engine is decreased in a compression control mechanism. The compression ratio is increased in the compression control mechanism at the time of operating the large turbocharger 17. |
