| 摘要 |
PROBLEM TO BE SOLVED: To substantialize early activation of a catalyst and HC reduction due to after-burning by drastic delay of ignition timing, and to avoid deterioration of smoke at a stage when fuel pressure is low. SOLUTION: At cold start of an internal combustion engine requiring early temperature rise of a catalytic convertor, ignition timing ADV is set to be after a compression top dead center, and super retard combustion for injecting fuel before the ignition timing ADV and after the compression top center is performed (a). Since turbulence inside a cylinder is improved due to high-pressure fuel injection immediately before the ignition timing ADV and flame spread is promoted, stable combustion can be realized. In particular, at the start, since fuel pressure is insufficient and smoke and HC is deteriorated, as in (b), the injection ratio of a compression stroke injection I1 is increased, and expansion stroke injection I2 is decreased. At a stage where fuel pressure is further lower, as in (c), the entire injection amount is of the compression stroke injection I1. COPYRIGHT: (C)2007,JPO&INPIT |
