Exhaust gas purification device for an internal combustion engine

An exhaust gas purification device for a compression-firing internal combustion engine having a direct cylinder fuel injection valve which injects fuel directly into a combustion chamber, said exhaust gas purification device comprising:

• a NO.sub.x absorbent which is disposed in an exhaust gas passage of an engine, and which absorbs NO.sub.x in an inflowing exhaust gas when the air-fuel ratio of the exhaust gas flowing into the NO.sub.x absorbent is lean and releases absorbed NO.sub.x when the oxygen concentration of the inflowing exhaust gas is lowered;
• excess air ratio reducing means for reducing the excess air ratio of the engine when the NO.sub.x absorbent is to release the absorbed NO.sub.x, thereby reducing the oxygen concentration of the exhaust gas flowing into the NO.sub.x absorbent;
• and
• combustion control means for controlling combustion of the engine, when the excess air ratio reducing means reduces the excess air ratio of the engine, in such a manner that the amount of the fuel injected from the direct cylinder fuel injection valve which contributes to pre-mixture fuel combustion in the combustion chamber is increased with respect to the amount of the fuel injected from the fuel injection valve which contributes to diffusive combustion in the combustion chamber.