The composition of the electronically controlled high-pressure common rail system

[1] Fuel supply system

1. Components of the fuel supply system

It is mainly composed of a fuel supply pump, common rail, fuel injector, etc.

[1] Fuel supply pump (high-pressure fuel pump) - Generates high pressure from fuel and supplies it to the common rail.

[2] Common rail - in fact, it is a fuel distribution pipe. The fuel stored in the common rail is sent to the fuel injector through the high-pressure fuel pipe at the appropriate time and injected into the engine cylinder.

[3] Fuel Injector - The fuel injector is a fuel injection valve controlled by an electromagnetic valve. The ECU controls the opening and closing of the electromagnetic valve, thereby controlling the fuel injection time and fuel injection volume of the fuel injector.

2. The working process of the electronically controlled common rail fuel injection system The working process of the electronically controlled common rail system

[II] Electronic Control System

The electronic control system consists of three parts: sensors, ECUs and actuators.

1. Transmitter - Collects the actual operating status information parameters of the engine and transmits them to the ECU.

The main sensors are:

[1] Engine speed sensors (crankshaft speed sensor, camshaft speed sensor)

The crankshaft speed sensor detects the engine speed signal, and the camshaft speed transmitter determines the working sequence.

[2] Accelerator pedal position sensor

Detect the position signal of the accelerator pedal (the driver's torque requirement).

[3] Air flow sensor (intake pressure sensor)

Detect the engine air flow signal.

[4] Booster pressure sensor

Test the boost pressure of the turbocharger.

[5] Coolant temperature sensor, intake air temperature sensor

The ECU makes the most accurate matching of the fuel injection rate at the fuel injection starting point and other parameters based on the values of the temperature sensor.

[6] Common rail pressure sensor

Collect the fuel pressure of the common rail, progress the reaction, and control the fuel pressure of the common rail.

2. ECU - Based on the actual operating status information of the engine transmitted by various sensors, it calculates, analyzes, and issues control instructions to control the fuel injection time, fuel injection volume, fuel injection rate, and fuel injection pressure. It has both self-diagnosis and emergency response functions for faults.

3. Actuator - Solenoid valve.

The opening and closing times of various solenoid valves are controlled by the ECU, and the fuel injection pressure of the common rail, the fuel injection time, fuel injection volume and fuel injection rate of the fuel injectors are also controlled.