PIEZO-ACTUATOR CONTROL DEVICE, PIEZO-ACTUATOR CONTROL METHOD AND FUEL INJECTION CONTROL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a piezo-actuator control device and a piezo-actuator control method in which an energy of piezo-stack is retained at constant even in the case where the piezo-stack is switched to charging during discharging. SOLUTION: A voltage of the piezo-stack 51 is compared with a voltage memorized in a sample hold circuit 75 by a comparison circuit and when the voltage of the piezo-stack 51 arrives at the voltage memorized in the sample hold circuit 75, a control circuit 70 finishes a charge stage of the piezo-stack 51. Thereby, an energy charged in the piezo-stack 51 can be equalized to the energy charged before discharging. When the charge stage of the piezo-stack 51 is finished by the control circuit 70, the voltage of the piezo-stack 51 is controlled to approximately the same as that at the time of former injection. If an electrostatic capacity of the piezo-stack 51 is equal, an electric energy charged in the piezo-stack 51 can be also equalized. COPYRIGHT: (C)2003,JPO