Control device of internal combustion engine

A control device of an internal combustion engine, the internal combustion engine comprising a supercharger that supercharges intake air, and being capable of changing a valve overlap characteristic between an intake valve and an exhaust valve, wherein the control device comprises:

• an air-fuel ratio sensor provided upstream of a turbine of the supercharger in an exhaust passage, detecting an air-fuel ratio of a mixture burning in a combustion chamber;
• a feedback correction value calculation part, calculating a feedback correction value for correcting a fuel injection amount so that a detected air-fuel ratio detected by the air-fuel ratio sensor becomes a target air-fuel ratio, by using a feedback control containing a predetermined gain;
• a reference feedback correction value setting part, setting a reference feedback correction value based on the feedback correction value;
• a scavenging control part, executing a scavenging control that scavenges the combustion chamber by causing a portion of the intake air flowing into the combustion chamber via the intake valve to flow out via the exhaust valve, by changing the valve overlap characteristic into a predetermined characteristic for scavenging control, in a state in which the intake air is supercharged by the supercharger;
• and
• a gain reduction control part, executing a gain reduction control that reduces the gain of the feedback control to be lower than during a normal control when the feedback correction value is changing relative to the reference feedback correction value in a direction of further correcting the fuel injection amount to a rich side during execution of the scavenging control.