| 摘要 |
PURPOSE:To eliminate a particular high voltage generating circuit, and thereby contrive the miniaturization of a device as well as an reduction in cost by constituting a piezo-actuator to be charged by surge voltage generated at the time of interrupting electrical continuity to an electromagnetic actuator mounted on a fuel injection pump. CONSTITUTION:One end of, for example, a timing control solenoid valve 36 acting as an electromagnetic actuator mounted on a fuel injection pump, is connected with a power transistor 67 forming a switching means driven by signals S1 from a CPU 65 in an ECU 60. And a signal line connecting the power transistor 67 with the solenoid valve 36 is connected with a piezo-actuator 55 via a diode 70 within a piezo-driving circuit 66. Furthermore, a discharge transistor 71 and a protective resistor 72 are connected with the piezo-actuator 55. And a piezo-actuator 55 is thereby charged by surge voltage generated at the time of interrupting electrical continuity to the solenoid valve 36 so as to let it be discharged at a specified intervals for letting pilot injection be processed.
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