Patent ID: 8794199

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; an EGR mechanism that feeds part of the exhaust gas through an EGR passage as EGR gas to the inside of a combustion chamber at an EGR rate; and an electronic control unit that is configured such that: at the time of engine low load operation, the mechanical compression ratio is made higher compared with the mechanical compression ratio at the time of engine high load operation; the higher the EGR rate, the higher an actual compression ratio is made; when the engine load is higher than the engine load at which the closing timing of the intake valve reaches a retarded-side limit closing timing, and is lower than the engine load at which the EGR rate reaches the set EGR rate, an actual compression ratio is increasing by advancing a closing timing of the intake valve; and when the engine load is lower than the engine load at which the closing timing of the intake valve reaches the retarded-side limit closing timing, the actual compression ratio is raised only by increasing the mechanical compression ratio.