| 主权项 |
1. A fuel injector comprising:
a cylindrical nozzle body; a nozzle needle axially moving in the cylindrical nozzle body; a pressure chamber defined between the nozzle needle and the cylindrical nozzle body for receiving a fuel therein; and an injection passage defined in the nozzle body to fluidly connect the pressure chamber and a cylinder of an internal combustion engine, wherein the fuel in the pressure chamber is injected into the cylinder as a fuel spray, the injection passage has a first hole which is opened to the pressure chamber and a second hole which is opened to the cylinder, an inner diameter of the second hole is larger than an inner diameter of the first hole, an outer periphery line of the fuel spray agrees with an inner wall of the second hole at a contact point, a minimum vertical distance between an outer periphery of a first nozzle hole outlet and the contact point relative to an axial center line of the first hole is defined as a vertical distance R, a minimum axial distance between the first nozzle hole outlet and the contact point relative to an axial center line of the first hole is defined as an axial distance L, an angle between the axial center line of the first nozzle hole and the outer periphery line of the fuel spray is defined as an injection angle θ, and the vertical distance R, the axial distance L and the injection angle θ satisfy a formula: R/(L×tan θ)>6.0. |
