| 摘要 |
PROBLEM TO BE SOLVED: To provide a simple and small-size fuel injection valve capable of setting the initial fuel injection rate low in a case of being used for a common rail type fuel injection device. SOLUTION: The fuel injection valve is provided with a control chamber 109 for retaining the hydraulic pressure energizing a needle in the valve opening direction, in the top of its needle 105. The control chamber communicates with a leak chamber 130 via hydraulic pressure return channels 201 and 203, and the leak chamber is connected to a low-pressure leak channel 107 via a control valve 300. The control valve 300 can take either of a first position cutting off the leak chamber from the leak channels, a second position closing the hydraulic return channel 203 and communicating only the hydraulic return channel 201 to the leak channel via the leak chamber, or a third position communicating the both hydraulic return channels to the leak channel via the leak chamber. The changeover between the second position and the third position can change the hydraulic pressure reducing speed of the control chamber so as to change the lifting speed of the needle.
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