SPARK-IGNITION DIRECT-INJECTION ENGINE

摘要

PROBLEM TO BE SOLVED: To reduce smoke and NOx while ensuring output in a high load region in a stratified combustion region. SOLUTION: A first nozzle hole (a specific nozzle hole and its axis indicated by a sign L1) is directed to a lower part near an electrode E of an ignition plug 16 projected into a combustion chamber 6. For instance, the magnitude of an ion current changed according to a local air-fuel ratio around the electrode is detected to grasp a distance X (X1-X4) between the electrode E and the axis L1 of the specific nozzle hole for every cylinder. In the high load region in the stratified combustion region, fuel injection timing set to a compression stroke is advanced as to the cylinder shortest in the distance X and delayed as to the cylinder longest in the distance X. COPYRIGHT: (C)2007,JPO&INPIT