Apparatus and method for controlling EGR in an engine

摘要

An engine including a recirculation passage, which connects an exhaust passage to an intake passage, and an EGR valve arranged in the recirculation passage. An electronic control unit (ECU) obtains a target opening degree of the EGR valve in accordance with an operating state of the engine and controls the EGR valve so that the opening degree of the EGR valve becomes equal to the obtained target opening degree. When opening the EGR valve from a fully closed state, the ECU restricts the opening degree of the EGR valve to a restricted opening degree that is smaller than the target opening degree during a predetermined delay time before actuating the EGR valve to the target opening degree. This prevent exhaust gas from being excessively recirculated to the intake passage even if the difference between the exhaust pressure and the intake pressure is too large when starting EGR.