Patent ID: 7444999

Claim:
A control system for an internal combustion engine which is operated while switching a combustion mode thereof between a compression ignition combustion mode in which an air-fuel mixture supplied to a combustion chamber is burned by compression ignition, and a spark ignition combustion mode in which the air-fuel mixture is burned by spark ignition, comprising: internal EGR control means for controlling an internal EGR amount of combustion gases caused to remain in the combustion chamber; target operating gas temperature-setting means for setting a target operating gas temperature as a target to which the temperature of operating gases in the combustion chamber is to be controlled in the compression ignition combustion mode; target internal EGR amount-setting means for setting a target internal EGR amount as a target to which the internal EGR amount is to be controlled, such that the temperature of operating gases in the combustion chamber becomes equal to the target operating gas temperature in the compression ignition combustion mode; and combustion mode-switching means for switching the combustion mode to the spark ignition combustion mode depending on the target internal EGR amount.