Internal combustion engine

摘要

A cylinder direct injection spark-ignition internal combustion engine comprising an EGR system is provided to control an amount of EGR gas recirculated from an exhaust gas passage to an intake air passage in which a throttle valve is disposed. The EGR system includes an EGR passage connecting the exhaust gas passage and the intake air passage, and an EGR valve disposed in the EGR passage. A control system is provided to control the EGR valve and the throttle valve. The control system includes a section for calculating a fresh air amount conversion value of an amount of the EGR gas, the fresh air amount conversion value being an amount of fresh air to be introduced to the intake system through the EGR system in place of the amount of the EGR gas. The control system further includes a section for controlling respective opening degrees of the throttle valve and the EGR valve in accordance with the fresh air amount conversion value.