| 摘要 |
PROBLEM TO BE SOLVED: To decrease a nozzle opening speed and increase a nozzle closing speed to control an injection amount with high accuracy and without leak, in an injector used for a common-rail fuel injection device or the like of a diesel engine. SOLUTION: A control valve part 102 of the injector 1 is three way valve structure. A space around a tip part 3a of a slide pin member 3 is provided with a restriction part 32 communicating with a low-pressure passage 13, and an approximately semispherical valve element 2 is driven. A diameter of a low-pressure side seat is less than or equal to a diameter of a high-pressure side seat. The pressure in a control chamber 4 communicating with a valve chest 21 is exerted as an assistance force, so that a high-pressure side seat closing load becomes less than or equal to a low-pressure side seat opening load. Since high-pressure side seat closing drive force is small, the nozzle closing speed can be increased, by increasing the diameter of the high-pressure side seat. COPYRIGHT: (C)2006,JPO&NCIPI
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