Patent ID: 7007638

Claim:
A variable compression ratio engine including: a connecting rod with one end connected to a piston via a piston pin; a subsidiary arm connected to a crankshaft via a crank pin with one end rotatably connected to the other end of the connecting rod; an eccentric shaft provided at an eccentric position of a rotary shaft rotatably supported at an engine body; and a control rod with one end connected to the subsidiary arm at a position deviated from the connecting position with the connecting rod and the other end pivotally connected to the eccentric shaft, wherein the engine further includes: a one-way clutch interposed between the rotary shaft and the engine body so as to restrict a rotating direction of the rotary shaft to one direction, the rotating direction of the rotary shaft corresponding to a rotational force which acts on the rotary shaft via the eccentric shaft from the control rod following a reciprocating operation of the piston; a restricted member linked and connected to the eccentric position of the rotary shaft to reciprocally operate in response to rotation of the rotary shaft; and a restricting means for switching a compression ratio to a high level and a low level by selectively restricting a rotational operation of the rotary shaft in either of two rotation phases different from each other in such a manner that the restricting means abuts to and engages with the restricted member immediately after the restricted member passes a reciprocation end.