| 摘要 |
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., when charged). SOLUTION: At the beginning of valve opening, a cylinder 22 is driven in the direction in which a second guide hole 221 is apart from a piston part 210 when a piezo actuator 14 extends, and the pressure in a first oil-tight chamber 25 lowers. A raising member 23 drives a nozzle needle 13 in the valve opening direction due to a reduction in the pressure in the first oil-tight chamber 25. Since the pressure in a second oil-tight chamber 27 lowers according to the movement of the raising member 23, the raising member 23 does not a tendency to move. Therefore, when a nozzle is lifted after the valve opening, the nozzle needle 13 is separated from the raising member 23, and moved to a full open position due to a reduction in the pressure in the first oil-tight chamber 5. COPYRIGHT: (C)2011,JPO&INPIT
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