Patent ID: 7681538

Claim:
An internal combustion engine which varies a compression ratio by changing a top dead center position of a piston, comprising: an engine block; the piston disposed in the engine block; a crank shaft supported by the engine block; a plurality of links connecting the piston and the crank shaft; a first control shaft and a second control shaft respectively supported by the engine block, each of which has a main shaft portion rotatably supported by the engine block and an eccentric portion eccentric to the main shaft portion, the eccentric portions of the first control shaft and the second control shaft deviating from axes of the respective main shaft portions in mutually different directions when viewed from an axial direction; a plurality of control links which connect any one of the plurality of links connecting the piston and the crank shaft, and the first control shaft and the second control shaft; and a driving unit which is provided at least one of the first control shaft and the second control shaft, that rotates the control shaft.