Original New Solenoid Valve E1022035 Control Valve Injector Coil for DENSO

With the help of solenoid valves on the injectors, the high-pressure common rail system allows diesel fuel to be injected at the correct injection pressure at the correct injection point with the correct amount of fuel injected, ensuring the best combustion ratio, atomization and optimum ignition time of the diesel engine, as well as good economy and the least amount of pollutant emissions.

Fuel control principle

The fuel is stored at a certain pressure in a high-pressure accumulator (the so-called "common rail") and is always ready for injection. The fuel injection amount is determined by the driver, and the injection starting point, injection duration and injection pressure are calculated by the ECU (Electronic Control Unit). Then, the ECU triggers the solenoid valve to cause the injector (injection unit) of each cylinder to inject accordingly.

How does a fuel injector work?

1. Solenoid valve is powered off: ball valve is closed

Control chamber pressure + needle valve spring pressure > needle valve chamber pressure needle valve closed - no injection

2. (1) The solenoid valve is energized: the ball valve opens and the oil drain hole drains oil.

(2) Control chamber pressure + needle valve spring pressure < needle valve chamber pressure, needle valve lifts - injection

The needle valve lifting speed depends on the flow difference between the drain hole and the oil inlet hole; the needle valve closing speed depends on the oil inlet hole flow rate

Injection response = solenoid valve response + hydraulic system response

Generally it should be 0.1ms~0.3ms (requirements for fuel injection rate control)