| 摘要 |
PROBLEM TO BE SOLVED: To ensure stable low temperature combustion by switching first combustion having rate of inert gas in a combustion chamber much more than a rate of inert gas where a soot generating rate becomes a peak level, and second combustion having few inert gas rate, and moving a first operating region to a high load side toward reducing an air-fuel ratio. SOLUTION: In a diesel engine 1 wherein EGR gas is re-circulated to an intake passage 17, a soot generating rate is gradually increased in the case where a rate of inert gas in a combustion chamber 5 is increased, a fuel and gas temperatures at the time of combustion are reduced lower than a soot generating temperature, and soot is hardly generated. First combustion wherein there is a rate of inert gas in the combustion chamber much more than a rate of inert gas where a soot generating rate becomes a peak level and the soot is hardly generated, and second combustion having few inert gas rate are freely switched. An operating region is divided into a first operating region of a low load side where first and second combustion are carried out, and a second operating region of a high load side, and the first operating region is moved to the high load side toward reducing an air-fuel ratio. |
