| 摘要 |
Retard combustion for warming up a catalyst is performed during an idling operation at a time of cold startup, and a rotation position as a reference of a control shaft is learned during the retard combustion. For example, the control shaft is rotated in a direction in which a compression ratio is reduced, a protruded piece portion of the control shaft is abutted against a low-compression ratio side stopper portion of a stopper member, a detection value of an angular position sensor in this state is learned as a learned value, and the compression ratio is detected with reference to the learned value until the next learning. As a result, even when a variable compression ratio mechanism is operated to perform the learning, operation noise at this time is canceled by combustion noise or the like of the internal combustion engine, and therefore does not give the driver a sense of discomfort. Further, because the learning of the rotation position as the reference of the control shaft is carried out during the retard combustion at the time of startup, deterioration of exhaust performance can be suppressed. |
