Kraftstoffeinspritzventil

PROBLEM TO BE SOLVED: To enhance the reliability of a piezo actuator while improving energy efficiency in a direct-acting fuel injection valve having a variable displacement magnification which is opened when the piezo actuator extends, i.e., the piezo actuator is charged. SOLUTION: A nozzle needle 13 is pressed in the valve opening direction when the pressure in an oil-tight chamber 25 lowers due to the movement of a cylinder 22 when a piezo actuator 14 extends, and the nozzle needle 13 is pressed in the valve opening direction through a lever 24. At the beginning of the extension of the piezo actuator 14, the nozzle needle 13 is driven in the valve opening direction by a drive force transmitted thereto mainly through the lever 24. When a nozzle is lifted after valve opening (i.e., after the extension of the piezo actuator 14), the nozzle needle 13 is driven to the full open position by the drive force due to a reduction in the pressure in the oil-tight chamber 25. COPYRIGHT: (C)2011,JPO&INPIT