CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

A control device of an internal combustion engine which is provided with an exhaust purification catalyst 20 is provided with a downstream side air-fuel ratio sensor 41, a feed control means for controlling the fuel feed amount so that the air-fuel ratio of the exhaust gas becomes a target air-fuel ratio, and an excess/deficiency estimating means which estimates an oxygen excess/deficiency in the exhaust gas. The target air-fuel ratio is switched to a lean air-fuel ratio when the output air-fuel ratio of the downstream side air-fuel ratio sensor becomes a rich air-fuel ratio and is switched to the rich air-fuel ratio when the stored amount of oxygen of the exhaust purification catalyst after this becomes a switching reference amount or more. An absolute value of cumulative oxygen excess/deficiency at a time period during which the target air-fuel ratio is made the lean air-fuel ratio and an absolute value of cumulative oxygen excess/deficiency at a time period during which the target air-fuel ratio is made the rich air-fuel ratio are used as the basis to correct the target air-fuel ratio etc. so that the difference of these absolute values becomes small.