| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure of a fuel injection nozzle capable of preventing increase in size of a piezo actuator even when a fuel pressure of a fuel passage is increased.SOLUTION: In a fuel injection nozzle 1 including a piezo actuator generating force to drive a needle 4 in a valve opening direction to separate a seat portion 21 from a seat position 20, the fuel in the fuel passage applies a fuel pressure in the valve opening direction to the needle 4 at an outer peripheral side of the seat portion 21 in a valve close state where the seat portion 21 is positioned on the seat position 20, and a throttle 50 for narrowing a cross-sectional area of a flow channel of the fuel passage 6 is disposed at a downstream side of the fuel flow with respect to a position where the fuel is divided to flow to a back pressure chamber 13 of the fuel passage 6. Thus the valve can be surely closed even when biasing force of biasing means 15 is reduced in comparison with a case free from the throttle 50, and the increase in size of the piezo actuator can be suppressed. |
