Made in China Good Quality 1817394C91 Diesel Fuel Injector Common Rail Injector Engine Parts

Structure
Fuel injector: It is the key component of the fuel injector, usually composed of a needle valve, a needle valve body, etc. The needle valve moves up and down in the needle valve body, and the fuel injection is controlled by controlling the opening and closing of the needle valve. The structural forms of the fuel injector are various, and the common ones are hole-type fuel injectors and pintle-type fuel injectors. The hole-type fuel injector is suitable for direct injection combustion chambers, with many spray holes and small apertures, which can make the fuel spray into a finer oil mist and mix evenly with the air; the pintle-type fuel injector is suitable for separated combustion chambers, with a pintle at the lower end of the needle valve, and the spray hole is annular. The fuel is sprayed from the gap between the pintle and the spray hole to form a hollow conical oil mist.
Fuel injector body: It is the main part of the fuel injector, used to install and fix the fuel injector, pressure regulating spring and other components, and provide a channel for the fuel. The injector body usually has an oil inlet, an oil return port, etc. The oil inlet is connected to the high-pressure oil pipe to receive high-pressure fuel from the injection pump; the oil return port is used to return the excess fuel in the injector to the fuel tank.
Pressure regulating device: generally composed of a pressure regulating spring, a pressure regulating screw, etc. The pressure regulating spring applies a certain preload through the pressure regulating screw. When the fuel pressure reaches the set value, the spring force is overcome to open the needle valve to achieve fuel injection. By adjusting the pressure regulating screw, the spring preload can be changed to adjust the injection pressure.

Working principle
When the injection pump delivers high-pressure fuel to the injector, the fuel enters the fuel inlet chamber of the injector body. As the fuel pressure continues to increase, when the pressure is greater than the preload of the pressure regulating spring, the needle valve is lifted and the fuel is sprayed into the combustion chamber through the spray hole of the injector nozzle. During the injection process, the injection pressure, injection time and injection amount of the fuel are precisely controlled by the engine control unit (ECU) according to the engine working conditions (such as speed, load, etc.). When the fuel pressure drops below the spring preload, the needle valve closes under the action of the spring force and fuel injection stops.