Patent ID: 8020533

Claim:
A fuel injection device for controlling a fuel injection valve including a solenoid and a magnetostrictive element that elongates when a magnetic field is applied thereto to generate a drive force for driving the fuel injection valve, the fuel injection device comprising: a solenoid driving power source for supplying current to the solenoid, wherein the solenoid includes a holding coil for providing electromagnetic attraction force; a solenoid drive circuit adapted to control the current passing through the solenoid, the current being supplied by the solenoid driving power source; a plurality of magnetostrictive element driving power sources for supplying current to a magnetostrictive coil of the magnetostrictive element, wherein the plurality of magnetostrictive element driving power sources includes at least a first magnetostrictive element driving power source and a second magnetostrictive element driving power source, wherein a boosting power source of the second magnetostrictive element driving power source is set higher than a boosting power source of the first magnetostrictive element driving power source; and a magnetostrictive element drive circuit adapted to control the current passing through the magnetostrictive coil of the magnetostrictive element, the current being supplied by either one of the magnetostrictive element driving power sources; wherein, in a valve-open mode, the holding coil is electrified by the solenoid driving power source and the magnetostrictive coil is electrified by the first magnetostrictive element driving power source; wherein, in a valve-closed mode, the magnetostrictive coil is electrified by the second magnetostrictive element driving power source.