Control system for internal combustion engine

Abstract

The present invention pertains to a control system for an internal combustion engine equipped with an exhaust gas purification apparatus including an NOcatalyst having an ability of reducing NOand a particulate filter, and its object is to prevent deterioration in the acceleration performance while preventing an increase in exhaust emissions when the temperature of the NOcatalyst is low. The control system for an internal combustion engine according to the present invention includes an exhaust gas purification apparatus provided in an exhaust passage of the internal combustion engine and including an NOcatalyst having an ability of reducing NOand a particulate filter, intake air quantity restriction means for restricting the intake air quantity in relation to the temperature of the NOcatalyst, fuel restriction means for restricting the fuel injection quantity in relation to the intake air quantity of the internal combustion engine, and trapped PM amount obtaining means for obtaining the amount of PM trapped in the particulate filter. When the amount of PM trapped in the particulate filter is not larger than a predetermined amount and the internal combustion engine is in an accelerating operation state, the control system corrects a restriction value of the fuel injection quantity in relation to the intake air quantity of the internal combustion engine and the temperature of the NOcatalyst.