VARIABLE COMPRESSION RATIO ENGINE

摘要

PROBLEM TO BE SOLVED: To reduce the driving load of the compression ratio variable mechanism of a variable compression ratio engine. SOLUTION: The working force that a support shaft 68 for rockably supporting a control rod 66 for regulating the track of the bent part 640 of a connecting rod 64 receives from the control rod 66 is detected by a strain gauge 85, and an ECU 81 is set so as not to operate a motor 71 for outputting a driving force for displacing the support shaft 68 from the present position to a prescribed position according to an instructed compression ratio when the detected working force is a prescribed magnitude in the direction reverse to the displacing direction of the support shaft 68 set on the basis of an instructed compression ratio or more, whereby the motor 71 is operated only when the working force is in the direction of assisting the drive of the support shaft 68 or it is such a small force that it never burdens the motor 71.