PURPOSE: To enable more precise pilot injection control by setting the time of transferring an electric charge to a piezo actuator for determining the initiation and completion of pilot fuel injection, the time of discharging thus transferred electric charge and a charged electric charge amount in accordance with the operating condition.
CONSTITUTION: During operation of a diesel-engine, a calculating means M3 calculates and electric charge charged to a piezo actuator M1 in accordance with an output from an operating condition detecting means M2, and a charging means M5 charges a capacitor M4 in accordance with the result of the calculation. Further, the charged electric charge is transferred to the piezo actuator M1 by a transfer means 6 so that the actuator M1 is extended to pressurize fuel in a high pressure chamber in an injection pump for initiating fuel injection. Further, when the electric charge transferred to the piezo actuator M1 is discharged through a discharge means 7, the fuel injection is terminated. These transfer time and discharge time are controlled by a control means M8 at predetermined times during fuel pressurization stroke of the fuel injection pump.
TAKEDA KEIZO
NAKAJIMA TATSUSHI
