FUEL INJECTION VALVE AND COMMON RAIL INJECTION SYSTEM

PROBLEM TO BE SOLVED: To attain a fuel injection valve capable of performing a boot type injection.SOLUTION: A fuel injection valve 1 comprises a main body part 10 having a fuel injection hole 15 formed at one end and a fuel supply flow passage 30 for supplying fuel to the fuel injection hole 15; and a needle valve 61 movably stored in the main body part 10 and shutting off a communication between the fuel injection hole 15 and the fuel supply flow passage 30 under a state in which it is sat at a seat part 16. In addition, the main body part 10 has a throttle forming passage 33b between the fuel injection hole 15 and the fuel supply flow passage 30. Then, under a state in which a distance between the needle valve 61 and the seat part 16 is less than a specified distance, a throttle part 80 is formed between an inner peripheral surface 82 of the throttle forming passage 33b and an outer peripheral surface 81 of a lower end part 61a of the needle valve 61 and under a state in which a distance between the needle valve 61 and the seat part 16 is more than a specified distance, the lower end part 61a of the needle valve 61 can be pulled out of the throttle forming passage 33b.SELECTED DRAWING: Figure 2 【課題】ブーツ型噴射を行うことができる燃料噴射弁を得る。【解決手段】燃料噴射弁１は、一端に形成された燃料噴射孔１５、及び、該燃料噴射孔１５に燃料を供給する燃料供給流路３０を有する本体部１０と、本体部１０の内部に移動自在に収納され、シート部１６に着座している状態では燃料噴射孔１５と燃料供給流路３０との連通を遮断するニードル弁６１と、を備える。また、本体部１０は、燃料噴射孔１５と燃料供給流路３０との間に絞り形成路３３ｂを有する。そして、ニードル弁６１とシート部１６との距離が規定距離上未満の状態においては、絞り形成路３３ｂの内周面８２とニードル弁６１の下端部６１ａの外周面８１との間で絞り部８０を形成し、ニードル弁６１とシート部１６との距離が規定距離以上の状態においては、ニードル弁６１の下端部６１ａが絞り形成路３３ｂから抜ける。【選択図】図２