CONTROL APPARATUS FOR AN INTERNAL COMBUSTION ENGINE

摘要

A control apparatus for an internal combustion engine having an exhaust gas purification device which is arranged in an exhaust passage and includes a NO x storage reduction (NSR) catalyst. The control apparatus, when the air fuel ratio of the air-fuel mixture is shifted from a lean air fuel ratio to the stoichiometric air fuel ratio, determines a predetermined NO x amount so as to be larger when the temperature detected by the first detection unit is high in comparison with when the detected temperature is low, and when the storage amount of NO x in the NSR catalyst is larger than the predetermined NO x amount, performs the rich spike processing and then controls the air fuel ratio to the stoichiometric air fuel ratio, whereas when otherwise, controls the air fuel ratio to the stoichiometric air fuel ratio without performing the rich spike processing.