PURPOSE: To provide a piezo-actuator drive circuit which distributes an electric charge to a plurality of pieze elements without using a switch used in selecting the piezo-element.
CONSTITUTION: A piezo-actuator drive circuit is constituted of a high voltage generating part 1 and a high voltage switching part 2. A piezo element 101 of a fuel injection valve 100 is electrically connected to the high voltage switching part 2, to supply high voltage, generated in the high voltage generating part 1, to the piezo-element 101. Timing of generating high voltage in a flyback transformers 14, 15 is set to just after ending fuel injection of the fuel injection valve 100, on the other hand to combine the fellow fuel injection valves 100 of cylinders #1/#4 or the fellow fuel injection valves 100 of cylinders #2/#3 with the injection timing not approaching, and high voltage, generated in the single flyback transformer 14 or 15, is supplied to each piezo-element 101 provided in the respective fuel injection valves 100.
MORINO SEIJI
MITSUYASU MASAKI
SAWADA DAISAKU
