| 摘要 |
PURPOSE:To change the angle of spray properly in accordance with an engine speed and a load by forming an auxiliary injection nozzle inside a pin protruded from the tip end of a needle valve and forming particular conical surfaces and enlarged portions on the side of the pin. CONSTITUTION:A needle valve 2 opens and closes an injection nozzle 8 continuing with a conical valve seat 7 formed on a nozzle body 1, and has a pin 9 formed on the tip end of the needle valve 2 and fitted into the injection nozzle 8. In this case, a conical surface 10 narrowing toward the injecting direction and a conical surface 11 enlarging toward the injecting direction are continuously provided on the side of the pin 9 in the way of the axial direction, and a base enlarged portion 12 and a tip end enlarged portion 13 are continuously formed with both the conical surfaces 10 and 11 on both sides in the axial direction. Also, an auxiliary injection nozzle 14 is provided inside the pin 9, and constituted of a lateral hole 15 and a vertical hole 16 which are opened on both the enlarged portions 12 and 13. At this time, each portion is set in size of: (D>d1, d2), (d1 d2), (L1 L2) respectively.
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