| 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: When a piezo actuator 14 extends, a cylinder 22 is driven toward the nozzle body 10 side, the volume of a first oil-tight chamber 26 is reduced, and the pressure in the first oil-tight chamber 26 rises. A raising member 23 drives a nozzle needle 13 in the valve opening direction due to a rise in the pressure in the first oil-tight chamber 26. Since the volume of the second oil-tight chamber 28 is increased and the pressure in the second oil-tight chamber 28 lowers according to the movement of the cylinder 22, a nozzle needle 13 is driven in the valve opening direction continuously due to a reduction in the pressure in the second oil-tight chamber 28. The displacement magnification is set so that the movement amount of the nozzle needle 13 is larger than that of the raising member 23. COPYRIGHT: (C)2011,JPO&INPIT
|
