Fuel injection control system for a diesel engine

Abstract

In a direct injection diesel engine in which fuel to be sprayed during a primary injection is split and sprayed at a plurality of timings at a point of time near top dead center of a compression stroke of a cylinder, a judger judges that a completion timing of the primary injection is later than a point of time corresponding to 35° after top dead center of a compression stroke when the primary injection is split while an engine is operated. Upon such a judgment, a split number of the primary injection and an injection intermission interval are reduced by a corrector to advance the injection completion timing. Further, an amount of fuel to be sprayed during the primary injection is reduced for correction, and a part of the fuel is preliminarily sprayed during the second half of the compression stroke of the cylinder by an auxiliary injection controller so as to respond to such a correction. Even in such an operating condition to require a larger amount of fuel to be sprayed, deterioration of fuel consumption and an increase of emissions can be prevented by hindering retardation of the injection completion timing later than the point of time corresponding to 35° after top dead center of the compression stroke.

Dependencies are inferred from the claim text.