摘要 |
The present invention relates to a fuel injection nozzle for a diesel engine. Disclosed is a fuel injection nozzle for a diesel engine, wherein the nozzle comprises: a main nozzle body on the bottom part of which is formed an injection port for injecting fuel into the combustion chamber of a diesel engine, and on one side of which is formed a fuel supply flow pathway; a hollow part which is formed inside the main nozzle body; a sac chamber which is formed at the bottom end of the hollow part and is connected to the injection port; a nozzle chamber which is formed between the hollow part and the sac chamber, and forms a space for the inflow of fuel via the fuel supply flow pathway; a needle which rises and falls along the hollow part and the nozzle chamber, and, while so doing, the bottom end part is made to open and close the sac chamber; a valve seating surface which is formed at an incline between the nozzle chamber and the sac chamber, and provides a surface for making hermetic contact against the bottom end of the needle; and an attenuating device which forms a hermetically sealed space between the bottom end part of the needle and the valve seating surface, and attenuates the speed of descent of the needle due to fuel remaining in the hermetically sealed space. Consequently, since the attenuating device for attenuating the speed of descent of the needle is provided between the bottom end part of the needle and the sac chamber, the impact loading which occurs when the needle descends and makes hermetic contact against the valve seating surface is attenuated and the durability of the needle and the valve seating surface is improved and, in addition, because the speed of descent of the needle valve is attenuated immediately before the bottom of the needle makes hermetic contact against the valve seating surface, it follows that there is hardly any effect on the fuel injection characteristics and there are no problems such as reduced fuel combustion efficiency in the engine due to the attenuating device. |