| 摘要 |
<P>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 thermal damage of a catalyst converter due to a rapid temperature rise. <P>SOLUTION: At cold start of an internal combustion engine requiring early temperature rise of a catalytic convertor, ignition timing is set after a compression top dead center, and super retard combustion for injecting fuel before the ignition timing and after the compression top dead center is performed. Since turbulence inside a cylinder is improved due to high-pressure fuel injection immediately before the ignition timing and flame spread is promoted, stable combustion can be realized. In super retard combustion, a high exhaust temperature can be obtained, and when the exhaust temperature is raised immediately after cold start, thermal distortion of the catalyst converter is increased. Therefore, until the catalyst temperature reaches the activation start temperature, the top dead center injection operation mode is prohibited. <P>COPYRIGHT: (C)2007,JPO&INPIT |
