| 摘要 |
PROBLEM TO BE SOLVED: To rapidly switch a combustion mode while preventing combustion stability from being lowered or emission properties from being deteriorated in a switching transient period of the combustion mode. SOLUTION: The controller for an engine comprises: a circulating gas concentration detecting means (air fuel ratio-in-EGR tube arithmetic means) 60s for obtaining a circulating gas concentration corresponding to an air fuel ratio in an EGR gas near an EGR valve, in a switching transient period of a lean state larger in the air fuel ratio in a combustion chamber than a theoretical air fuel ratio and a rich state smaller in the air fuel ration than a substantially theoretical air fuel ratio or a theoretical air fuel ratio; and an intake amount correcting means 56c for correcting the intake amount by comparing the circulated gas concentration with a target air fuel ratio in the combustion chamber in the switching transient period, driving the opening of the throttle valve in an increasing direction if the circulated gas concentration is more dense than the target air fuel ratio, and driving the opening of the throttle valve in the decreasing direction if the circulated gas concentration is thinner than the target air fuel ratio. COPYRIGHT: (C)2003,JPO
|
