| 摘要 |
PROBLEM TO BE SOLVED: To materialize an exhaust gas temperature rise and an HC exhaust amount reduction in a cold state by achieving both a large delay of ignition timing and combustion stability. SOLUTION: In a warm-up completed state where cooling water temperature exceeds 80°C, normal stratified combustion operation and homogeneous combustion operation are executed. In a cold state where cooling water temperature is 80°C or lower, top dead center injecting operation is executed to promote activation of catalyst converter. Under this constitution, injection start timing ITS is before the compression top dead center. Injection completion timing ITE is after the compression top dead center. The fuel injection is carried out over the compression top dead center TDC. The ignition timing is after the compression top dead center. In the top dead center, the swirl flow and tumble flow are broken to become a stable place and minute disturbance is actively generated to improve combustion stability. As a result, the large delay of the ignition timing is allowed. At high load, cylinder pressure rises more than that at low load. Therefore, the injection start timing ITS is advanced so as to materialize reliable spray forming. COPYRIGHT: (C)2006,JPO&NCIPI |
