| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive unit which comprises an internal combustion engine including a variable compression ratio mechanism, and suppresses noise which is generated when a mechanical compression ratio is reduced.SOLUTION: A drive unit comprises an internal combustion engine having a variable compression ratio mechanism, and a continuously variable transmission. The variable compression ratio mechanism includes a motor for changing a mechanical compression ratio, and a clutch for blocking a reverse input to the motor. In an operation region of the internal combustion engine, there are set a region B in which a lock of the clutch is generated and noise is generated when the mechanical compression ratio is reduced, and a region C whose load is larger than that of the region B, and in which noise is permitted. When the internal combustion engine is transited to the region C during an operation in the region B, a gear change ratio of the continuously variable transmission is increased and an engine rotation number is increased, and after the increase of the engine rotation number is finished, the internal combustion engine is transited to the region C by increasing an intake air amount, and the mechanical compression ratio is reduced in the region C. |
