Control device for internal combustion engine

Abstract

To enable a three-way catalyst to exert high exhaust emission control performance regardless of the degree of deterioration of the three-way catalyst.SOLUTION: A control device 80 can execute: processing of calculating a feedback value for matching the air-fuel ratio and the theoretical air-fuel ratio of exhaust gas on a downstream side of a first catalyst 32; processing of calculating a catalyst correction value such that a target air-fuel ratio in a cylinder 12 is corrected to the richer side as an intake air amount increases; processing of calculating the target air-fuel ratio based on the feedback value and the catalyst correction value; processing of controlling a fuel injection amount of an injector 22 so that the air-fuel ratio of exhaust gas on an upstream side of the first catalyst 32 matches with the target air-fuel ratio; and processing of calculating the degree of deterioration of the first catalyst 32. Assuming that the intake air amount is the same, in the processing of calculating the catalyst correction value, when the degree of deterioration of the first catalyst 32 is a first deterioration degree, the catalyst correction value is calculated so that the amount of correction to the richer side is greater than that when the first catalyst 32 is at a second deterioration degree that is lower than the first deterioration degree.SELECTED DRAWING: Figure 1

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