DEVICE FOR CHARGING/DISCHARGING PIEZOELECTRIC ELEMENT, METHOD FOR CHARGING PIEZOELECTRIC ELEMENT IN SYSTEM AND APPLICATION PARTICULARLY ADAPTABLE FOR USE IN FUEL INJECTION SYSTEM

摘要

PROBLEM TO BE SOLVED: To lower an average current in periods for charging and discharging an piezoelectric element for use in a fuel injection system.;SOLUTION: This device for charging/discharging the piezoelectric element controls a current flowing in the system, as a function for time characteristics and event characteristics. One terminal of the piezoelectric element 1 is constantly connected to an earth, namely, connected to a first pole of a voltage source. The other terminal of the piezoelectric element is connected to a second pole of the voltage source via a coil 2 and a parallel circuit consisting of a charging switch 3 and a diode 5 and connected to the first pole of the voltage source via the coil 2 and a parallel circuit consisting of a discharging switch 5 and a diode 6. The voltage source has a battery 7 (for example, an on-vehicle battery), a DC circular pressure converter 8 downstream therefrom and a capacitor 9 serving as a buffer capacitor.;COPYRIGHT: (C)2002,JPO