Patent ID: 7827957

Claim:
A diesel engine control device for controlling the injection quantity and injection timing of fuel injected into a cylinder of a diesel engine comprising a reentrant-type cavity provided in a top portion of a piston, wherein are provided two control modes of: a normal injection mode in which the injection quantity and injection timing are controlled so that the injected fuel ignites near compression top dead center during an injection period, and in which a pilot injection and a main injection are carried out; and a premixed injection mode in which the injection quantity and injection timing are controlled so that fuel injection is completed before compression top dead center and the injected fuel ignites near compression top dead center after a premixing period, and in which only a main injection is carried out; wherein an injection angle and the injection timing are set so that the injected fuel enters the cavity and burns in the cavity in both control modes; wherein target values of control parameters are set in advance separately for each control mode, wherein the diesel engine control device comprises change means for gradually changing the target values of one control mode into the target values of the other control mode when switching from one control mode to the other control mode, and wherein the injection timing of the main injection in the normal injection mode is fixed when switching from one control mode to the other control mode.