| 摘要 |
PROBLEM TO BE SOLVED: To avoid thermal degradation of a catalyst due to an excessively high temperature while attaining early activation of the catalyst and HC reduction by after-burning with a considerable delay of ignition timing. SOLUTION: At the cold start of an internal combustion engine which requires the early temperature rise of a catalytic converter, the ignition timing is set after the compression top dead center, and super retard combustion of injecting fuel before the ignition timing and after the compression top dead center is performed. Turbulence in a cylinder is improved by high pressure fuel injection immediately before the ignition timing, and flame propagation is accelerated to achieve stable combustion. In this super retard combustion, an exhaust temperature becomes very high, and if it continues to the complete active temperature of the catalyst, there is a problem of thermal degradation. A top dead center injection operation mode is thereby released in a predetermined stage before complete activity. COPYRIGHT: (C)2007,JPO&INPIT |
