SPARK-IGNITED INTERNAL COMBUSTION ENGINE

摘要

An internal combustion engine comprises a variable compression ratio mechanism (A) capable of varying the mechanical compression ratio and a variable valve timing mechanism (B) capable of controlling the closing timing of an intake valve (7). In a low-load operating range except an idling operation, the mechanical compression ratio is maintained at a maximum mechanical compression ratio, and in the idling operation, the mechanical compression ratio is lower than the maximum mechanical ratio.