COMPRESSION IGNITION INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To prevent the deterioration of activity of a catalyst. SOLUTION: First combustion which has an EGR gas amount is a combustion chamber 5 larger than an EGR (exhaust recirculation) gas amount at peak generation amount of soot and hardly generates soot, and second combustion which has the EGR gas amount in the combustion chamber 5 smaller than the EGR gas amount at peak generation amount of soot are selectively performed. The first and the second combustion are performed under lean air- fuel ratio. The air-fuel ratio is generated temporarily rich just before switching from the first combustion to the second combustion or just after switching from the second combustion to the first combustion.