What is the working principle of a fuel injector?

[SanBrooklyn]

The fuel injector is a simple solenoid valve. Below is an introduction to its working principle: 1. When the electromagnetic coil is energized, it generates a magnetic force that lifts the needle valve, opening the injection hole. Fuel is then sprayed at high speed through the annular gap between the needle valve head and the injection hole, forming a mist that facilitates complete combustion. 2. The fuel injector itself is a normally closed valve. A normally closed valve remains closed when there is no input control signal, whereas a normally open valve remains open without a control signal. The opening and closing of the valve are controlled by the up-and-down movement of a valve needle. 3. When the ECU issues a fuel injection command, its voltage signal causes current to flow through the coil inside the fuel injector, generating a magnetic field that lifts the valve needle, allowing the valve to open and enabling fuel to be sprayed out through the injection hole.