| 摘要 |
PROBLEM TO BE SOLVED: To reduce the opportunity of generating soot upon change-over be tween low temperature combustion and second combustion by enlarging an engine operating range in which the low temperature combustion can be carried out, while inhibiting emission of soot and NOx simultaneously. SOLUTION: If the changeover can be made between low temperature combustion feeding exhaust gas recirculation(EGR) gas into a combustion chamber 5 by a volume larger than the volume of EGR gas with which the quantity of generated soot becomes peak, so as to generate substantially no soot, and second combustion feeding EGR gas into the combustion 5 by a volume smaller than the volume of EGR gas with which the quantity of generated soot becomes peak, during low temperature combustion which can be carried out only under low or middle engine load, the speed shift point of an automatic transmission 60 is shifted from second combustion toward the high speed side and the low load side so as to select a low speed side gear in order to reduce the load while sustaining the same workload (load × rotational speed), thereby it is possible to substantially enlarge the engine operating range which can carry out the low temperature combustion. |
