CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine that enables suppression of outflow of NOx.SOLUTION: A control device for an internal combustion engine performs normal operation control including lean control for making an air-fuel ratio of exhaust gas flowing in to an exhaust purification catalyst lean and rich control for making the air-fuel ratio of the exhaust gas flowing in to the exhaust purification catalyst rich. The control device detects an air-fuel ratio of exhaust gas flowing out from the exhaust purification catalyst for an execution period of the normal operation control, and performs control for making the air-fuel ratio of the exhaust gas flowing in to the exhaust purification catalyst become an auxiliary rich setting air-fuel ratio that is richer than a theoretical air-fuel ratio even if amount of oxygen stored in the exhaust purification catalyst does not reach determination reference storage amount when the air-fuel ratio of the exhaust gas flowing out from the exhaust purification catalyst reaches a lean determination air-fuel ratio or larger.