| 摘要 |
PROBLEM TO BE SOLVED: To provide an internal combustion engine having a variable compression ratio mechanism which can change a mechanical compression ratio by a small-sized rotating machine.SOLUTION: An internal combustion engine comprises a variable compression ratio mechanism which can change a mechanical compression ratio by changing a relative position of a cylinder block with respect to a crank case. The variable compression ratio mechanism includes a motor, a reverse input block clutch which is disposed in a passage for transmitting a rotation force of the motor, and a lift spring which energizes the cylinder block toward a direction in which the cylinder block is separated from the crank case. When a requirement is issued which lowers the mechanical compression ratio during a stop period of an engine main body, the internal combustion engine determines whether or not first torque of an input shaft necessary for releasing a locked state of the clutch is smaller than second torque which can be supplied to the input shaft by the motor, and when the first torque is smaller than the second torque, the internal combustion engine lowers the mechanical compression ratio. |
