Compression ignition type engine

摘要

A compression ignition type engine comprising an NOx absorbent arranged in its exhaust passage. This NOx absorbent absorbs NOx when the air-fuel ratio of the inflowing exhaust gas is lean and releases the absorbed NOx when the air-fuel ratio of the exhaust gas is rich. When NOx should be released from the NOx absorbent, the mean value of the air-fuel ratio in the combustion chamber is changed from lean to rich. At least at this time, use is made of fuel containing oxygen as the injected fuel.