| 摘要 |
PROBLEM TO BE SOLVED: To highly accurately inject a very small quantity by an injector 1, even if injection pressure is high. SOLUTION: In this injector 1, when a needle 33 lifts, pressure of a back pressure relieving chamber 46 is reduced since fuel flows out of the back pressure relieving chamber 46. In this injector 1, fuel flow passages 41 and 48 are set so that a pressure reducing speed of the pressure of the back pressure relieving chamber 46 becomes larger than a pressure reducing speed of pressure of a back pressure chamber 38. Thus, when the needle 33 lifts, since the pressure of the back pressure relieving chamber 46 is early reduced more than the pressure of the back pressure chamber 38, energizing force acting in the valve opening direction on the needle 33, early becomes weaker than energizing force acting in the valve closing direction on the needle 33. Thus, a lift speed of the needle 33 reduces. As a result, even if the injection pressure is the high pressure, the very small quantity can be highly accurately injected. COPYRIGHT: (C)2007,JPO&INPIT
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