Patent Document ID: 9903297
Application ID: 15110597
Patent Flag: 1

Claim One:
1. A control system of an internal combustion engine comprising an exhaust purification catalyst arranged in an exhaust passage of the internal combustion engine and able to store oxygen, and a downstream side air-fuel ratio sensor arranged at a downstream side of the exhaust purification catalyst in a direction of exhaust flow and detecting an air-fuel ratio of exhaust gas flowing out from the exhaust purification catalyst, wherein the control system performs feedback control of an amount of fuel fed to a combustion chamber of the internal combustion engine so that an air-fuel ratio of exhaust gas flowing into the exhaust purification catalyst becomes a target air-fuel ratio and performs learning control to correct a parameter relating to the feedback control based on an air-fuel ratio of exhaust gas detected by the downstream side air-fuel ratio sensor, the target air-fuel ratio is alternately switched between a rich set air-fuel ratio richer than a stoichiometric air-fuel ratio and a lean set air-fuel ratio leaner than the stoichiometric air-fuel ratio, and when a condition for learning acceleration, which is satisfied when it is necessary to accelerate correction of the parameter by the learning control, is satisfied, a rich degree of the rich set air-fuel ratio is increased.