High Quality Auto Parts Diesel Fuel Injector 095000-8011 Fuel Injector Engine Parts

The working principle of the fuel injector is mainly based on electromagnetic control or piezoelectric effect to achieve fuel injection. The working principles of electromagnetic fuel injectors and piezoelectric fuel injectors are introduced below:

Working principle of electromagnetic fuel injector
Structural basis: The electromagnetic fuel injector is mainly composed of fuel injector nozzle, electromagnetic coil, armature, spring and other components. The fuel injector nozzle is the outlet of fuel injection, and there is a needle valve inside it. The opening and closing of the needle valve controls the injection of fuel. The electromagnetic coil surrounds the armature. When the electromagnetic coil is energized, a magnetic field is generated. The spring acts on the needle valve to keep it closed when it is not energized, preventing the fuel from flowing out.

Working process
Power on: When the engine control unit sends a fuel injection signal, current passes through the electromagnetic coil to generate a magnetic field. The magnetic field attracts the armature, overcomes the elastic force of the spring, and causes the armature to drive the needle valve downward to open the fuel injector. At this time, the fuel is sprayed out through the spray hole of the fuel injector under the action of the fuel system pressure to form a mist. The amount of fuel injection depends on the length of time the injector nozzle is open, that is, the duration of the electromagnetic coil being energized. The longer the energization time, the greater the amount of fuel injection.

Power-off shutdown: When the injection signal ends, the current in the electromagnetic coil is cut off and the magnetic field disappears. The elastic force of the spring returns the armature and the needle valve to the initial position, the injector nozzle is closed, and the fuel stops injecting.

Working principle of piezoelectric injector
Structural basis: The piezoelectric injector utilizes the piezoelectric effect of piezoelectric materials. The main components include piezoelectric elements, injectors, push rods, etc. Piezoelectric elements are usually composed of multilayer piezoelectric ceramic sheets. When voltage is applied to the piezoelectric element, the piezoelectric ceramic sheet will undergo slight deformation. The push rod connects the piezoelectric element and the needle valve of the injector nozzle, transmits the deformation of the piezoelectric element to the needle valve, and controls its opening and closing.
Working process

Electric deformation: When the engine control unit issues an injection command, a certain voltage is applied to the piezoelectric element. Under the action of voltage, the piezoelectric element will quickly produce a slight expansion deformation. This deformation is transmitted to the needle valve of the fuel injector through the push rod, overcoming the elastic force of the needle valve spring, causing the needle valve to open, and fuel is ejected from the fuel injector under the action of the fuel system pressure.

Power-off reset: When the voltage is removed, the piezoelectric element returns to its original shape, the push rod also returns to its original position, and the needle valve closes the fuel injector under the action of the spring, stopping fuel injection. Compared with electromagnetic fuel injectors, piezoelectric fuel injectors have faster response speeds and can more accurately control the injection timing and amount, especially when the engine is running at high speed or the injection amount needs to be adjusted frequently, and have better performance.