Patent ID: 8413618

Claim:
A spark ignition type internal combustion engine comprising: a variable compression ratio mechanism able to change a mechanical compression ratio, a variable valve timing mechanism able to control a closing timing of an intake valve, a throttle valve arranged in an engine intake passage for controlling an intake air amount, and a controller that is programmed to control such that: the closing timing of the intake valve is made to shift as an engine load becomes lower in a direction away from an intake bottom dead center, the mechanical compression ratio is made to increase until a maximum mechanical compression ratio as the engine load decreases, at an engine low load operation side of a load lower than an engine load where the mechanical compression ratio becomes the maximum mechanical compression ratio, the mechanical compression ratio is held at the maximum mechanical compression ratio and an actual compression ratio is made to decrease as the engine load decreases, a load at which the mechanical compression ratio becomes a value between the maximum mechanical compression ratio and the mechanical compression ratio at the time of full load operation at an engine high load operation side is preset, and the throttle valve is closed at a load region lower than the preset load.