Patent ID: 6959541

Claim:
A fuel injection control system of an internal combustion engine having a particulate filter disposed in an exhaust passage for collecting particulate matters included in exhaust gas, wherein the engine performs a post-injection in an expansion stroke or an exhaust stroke after a main injection and heats the particulate filter with reaction heat generated when fuel injected in the post-injection is combusted by an oxidization catalyst in order to eliminate the collected exhaust particulate matters by combustion and to regenerate ability of the particulate filter to collect the exhaust particulate matters, the system comprising: temperature measuring means for measuring temperature of the exhaust gas at the inlet portion of the particulate filter, the temperature measuring means being disposed upstream of the oxidization catalyst and the particulate filter; and injection quantity setting means for setting a post-injection quantity for the post-injection so that the post-injection quantity increases in accordance with an increase in the temperature of the exhaust gas measured by the temperature measuring means in an early stage of the regeneration of the particulate filter; wherein the injection quantity setting means sets the post-injection quantity for a first post-injection to be smaller than a predetermined injection quantity corresponding to a heating value at which the collected exhaust particulate matters can be eliminated when the measured temperature is lower than a white smoke inhibition temperature.