The function of the injector is to atomize the diesel oil into finer particles and distribute them into the combustion chamber. According to the requirements of the formation and combustion of the mixture, the injector should have a certain injection pressure and range, as well as a suitable injection cone. In addition, the fuel injector should be able to quickly cut off the fuel supply at the specified stop injection time without dripping. The injector assembly is composed of the injector body, the injector coupler, the tight cap, the ejector rod, the pressure regulating screw, etc. The working principle of the injector: When the axial force of the high-pressure fuel acting on the needle valve of the injector exceeds the preload of the pressure regulating spring, the needle valve is lifted (opened), and the fuel passes through the injection nozzle on the injector. The holes are sprayed into the combustion chamber. When the fuel supply is interrupted, under the action of the pressure regulating spring, the needle valve of the fuel injection nozzle is pressed against the sealing cone surface of the fuel injection nozzle body (closed), and the fuel injection stops.