FUEL INJECTION CONTROLLER OF INTERNAL COMBUSTION ENGINE

A systematic fuel injection control technique for compression self-igniting internal combustion engines capable of executing an auxiliary injection prior to a primary injection is provided, with which it is possible to optimize an injection mode for the primary injection and the auxiliary injection. In a common rail diesel engine 1 capable of executing at least a main injection and a pre-injection as an operation of fuel injection from an injector 23, the pre-injection is executed by being split into a first pre-injection and a second pre-injection. The injection timing and the injection amount of each fuel injection is controlled such that some of the fuel injected in the first pre-injection combusts by self-ignition, and the remainder of the fuel does not combust until fuel is injected in the main injection, but combusts together with the fuel injected in the main injection. Also, the injection timing of each fuel injection is controlled such that the fuel injected in the first pre-injection and flowing along a swirl flow in the cylinder overlaps the fuel injected in the subsequent main injection.