Composition of electronically controlled Common rail system
Mainly composed of two parts: fuel supply and electronic control system.
〔1〕 Fuel supply system
1. Composition of fuel supply system
Mainly composed of fuel supply pump, common rail, fuel injector, etc.
〔1〕 Fuel supply pump [high-pressure fuel pump] - generates high pressure of fuel and supplies it to the common rail.
〔2〕 Common rail - actually a fuel distribution pipe, where the fuel stored in the common rail is fed into 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 an injection valve controlled by a solenoid valve, and the ECU controls the opening and closing of the solenoid valve, thereby controlling the injection time and quantity of the fuel injector.
2. The Working Process of the Electronic Controlled Common Rail Fuel Injection System
〔2〕 Electronic control system
The electronic control system consists of three parts: sensors, ECU, and actuators.
1. Sensor - collects the actual operating status information parameters of the engine and transmits them to the ECU.
The main sensors are:
〔1〕 Engine speed sensor [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 accelerator pedal position signal [driver torque requirements].
〔3〕 Air flow sensor [intake pressure sensor]
Detect the engine air flow signal.
〔4〕 Boost pressure sensor
Check the boost pressure of the turbocharger.
〔5〕 Coolant temperature sensor, intake air temperature sensor
The ECU matches the injection rate and other parameters at the starting point of the fuel injection according to the values of the temperature sensor.
〔6〕 Common rail pressure sensor
Collect common rail fuel pressure, progress 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, calculates, analyzes, and issues control commands to control the progress of fuel injection time, fuel injection quantity, fuel injection rate, and fuel injection pressure. It has both fault self-diagnosis and fault emergency functions.
3. Actuator - solenoid valve.
The ECU controls the opening and closing times of various solenoid valves, controlling the injection pressure of the common rail, the injection time, injection quantity, and injection rate of the fuel injectors.
