Drive circuit for an electrostrictive actuator in a fuel injection valve

摘要

In a drive circuit for electrostrictive actuators provided to fuel injection valves in an internal combustion engine, the drive circuit is constituted by a capacitor connected to a direct current voltage source; a switching element connected to the capacitor and used for charging; a first inductor connected to the switching element and used for charging; a plurality of piezoelectric elements used as the electrostrictive actuator; a plurality of other switching elements each connected to each of the piezoelectric elements and used for discharging; a plurality of diodes each connected to each of the piezoelectric elements and used for clamping; and a second inductor connected to each of the piezoelectric elements through each of the switching elements and used for discharging; wherein, at the time of charging, all of the piezoelectric elements are simultaneously charged by turning ON the switching element for charging, and at the time of discharging, predetermined piezoelectric elements are sequentially discharged in correspondence with a fuel injection timing.