What Are The Components Of The Engine Fuel Supply System?

The engine fuel supply system is mainly composed of the following parts:
Fuel tank (oil storage) - fuel pump (refueling) - fuel filter) pressure regulation (excess oil returns to the tank) - refueling rail - fuel nozzle (injection)
1. Fuel supply system (oil circuit).
The function of the fuel supply system is to supply gasoline for combustion in the cylinder.
The fuel supply system includes fuel tank, fuel pump, fuel buffer, fuel pressure regulator, fuel filter, injector, thermostat timing switch, cold start valve (cold start injector) and other components.
2. Fuel tank (gasoline tank) - used for fuel storage.
Fuel pump (electric gasoline pump) - It is used to pump fuel from the fuel tank into the fuel pipeline, keep the fuel at a certain pressure, and deliver it to the fuel injector and cold start valve through the filter.
The fuel pump can be divided into two types of external pump and interior pump according to its installation position, namely, the pump is installed on the pipeline outside the fuel tank, and the interior pump is installed in the fuel tank. Compared with the externally mounted pump, it is less prone to air resistance and fuel leakage, and has low noise. At present, most EFIs use built-in pumps.
3. Fuel buffer
Also called pulsation damper. Its function is to make the hydraulic pressure of the fuel pump smooth, reduce the fluctuation of the pump and reduce the noise.
4. Fuel pressure regulator
A pressure regulator is installed in the oil circuit to keep the fuel pressure constant relative to the air pressure or negative pressure of the intake pipe. In other words, the difference between the injection pressure and the injection ambient pressure is kept constant. This pressure difference is usually maintained at 250kPa. When the oil supply pressure exceeds the specified value, the pressure reducing valve in the pressure regulator opens, and the gasoline returns to the oil tank through the oil return pipe, and the oil pipe hydraulic pressure remains constant.
5. Fuel filter
It is put into the oil circuit between the fuel injector and the fuel injector to remove water, impurities and other contaminants in the fuel and not block the instrument valve of the fuel injector.
6. Ejector
The injector is set at the air inlet of the throttle body (SPI system) or the intake manifold is set near the intake valve of each cylinder (MPI system), which is controlled by the injection signal of the electronic controller. The injection amount is determined by the length of the power on time of the injector
The injection principle of the injector is to send the injection current signal from the controller. The current flows through the electromagnetic coil to generate electromagnetic attraction, which attracts the iron core. The needle valve is integrated with the iron core. At this time, the instrument valve is opened and fuel is ejected from the injector.
7. Thermostatic timing switch and cold start valve (cold start injector).
The thermostat switch is used to monitor the temperature of the cooling water, start the engine, close the switch contact when the temperature of the cooling water is 114 (c) low, and inject oil into the cold start valve.
The cold start valve is used to inject extra fuel into the intake manifold when the engine is cold started, so as to improve the cold start performance. Some cars have cancelled the temperature control timing switch, and the cold start injector is completely controlled by the ECU, so the control accuracy is higher.