Injector type and structure
a. According to the fuel injection structure can be divided into: shaft pin type, hole type.
b. According to the coil resistance value: high resistance (13 ~ 16Ω), low resistance (2 ~ 3Ω).
c. According to the purpose: MPI, SPI.
d. According to fuel position: upper oil supply, side oil supply
a. The injector is equivalent to a solenoid valve.
b. When the power is energized, the electromagnetic coil generates electromagnetic force, the armature and the needle valve are sucked up, the injector is opened, and the gasoline is injected into the intake port or the intake pipe through the injection hole.
c. When the power is off, the electromagnetic force disappears. The armature and the needle valve close the nozzle under the action of the return spring, and the injector stops the injection.
d. The power-on and power-off of the injector are controlled by the electric control unit with electric pulse.
e. The amount of fuel injected is determined by the width of the electrical pulse. Pulse width = injection duration = fuel injection.
f. The general needle valve lift is about 0.1mm, and the fuel injection duration is in the range of 2~10ms.