Drive circuit for an electrostrictive actuator in a fuel injection valve

A drive circuit for electrostrictive actuators provided to fuel injection valves in an internal combustion engine comprising:

• a capacitor connected to a direct current voltage source;
• a switching element connected to said capacitor and used for controlling the time of charging of piezoelectric elements;
• a first inductor connected to said switching element and used at the time of charging of the piezoelectric elements;
• a plurality of piezoelectric elements used as said electrostrictive actuator;
• a plurality of other switching elements each connected to each of said piezoelectric elements and used for controlling the time of discharging of the piezoelectric elements;
• a plurality of diodes each connected to each of said piezoelectric elements and used for clamping;
• and
• a second inductor connected to each of said piezoelectric elements through each of said switching elements and used at the time of discharging of the piezoelectric elements;
• wherein at the time of charging all of said piezoelectric elements are simultaneously charged by turning ON said switching element for controlling the time of charging, and at the time of discharging, predetermined piezoelectric elements are sequentially discharged in correspondence with a fuel injection timing.