| 摘要 |
PROBLEM TO BE SOLVED: To reduce a capacity of a suction chamber without lowering an injection rate at the initial stage of injection, in a fuel injection nozzle for injecting fuel to an internal combustion engine.SOLUTION: A nozzle 1 includes a hollow 12 disposed at a tip side in the axial direction with respect to a seat portion 13, on a surface of a needle 2. By the existence of the hollow 12, a fuel passage in the initial stage of injection immediately after separation of the seat portion 13 from a seat position 10 can be enlarged, and the lowering of the injection rate at the initial stage of injection can be suppressed even when a tip portion 2b is largely projected to a suction chamber 18. Further by adjusting a volume of the hollow 12, increase of the capacity of the suction chamber 18 in accompany with formation of the hollow 12 can be minimized. Accordingly, the capacity of the suction chamber 18 can be reduced without lowering the injection rate at the initial injection in the nozzle 1. |
