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General information about the injection system ?�Common Rail?�
Location injection system ?�Common Rail?� diesel 4-cylinder engine The main element of the fuel injection system is a fuel pump, which is installed on all diesel engines. The injection pressure up to 1350 bar is necessary to increase the power up to 160 kW per cylinder. In recent years, many developed diesel fuel injection systems, in particular, direct injection (Dl). This was done not only the task of increasing engine power, but also reducing fuel consumption and reducing noise and emissions. Compared with the previously used systems, fuel injection system Bosch ?�Common Rail?� (common rail system) for direct fuel injection (Dl) provides greater flexibility in adapting to the power supply system of the diesel engine, for example: - An extensive range of applications (for cars and commercial vehicles with a power output of 30 kW per cylinder, as well as for heavy-duty trucks, locomotives and ships with a power output of 200 kW per cylinder;
- High fuel injection pressure up to 1400 bar;
- Change in the injection when the engine is started;
- The ability to control, master and late injection;
- Ensures that the injection pressure of the operating mode of the engine.
The functioning of the injection system The distinctive characteristic of the system with a total pipeline ?�Common Rail?� (common rail system) is to divide the unit, creating pressure, and the fuel injection unit. The system is based tank (battery). The injection pressure is independent of the fuel injection quantity and the engine speed of the engine. Margin pressure fuel stored in the high pressure accumulator ?�Common Rail?� and ready for injection. The amount of fuel injected is determined by the demand of the driver, and the injection pressure is calculated by the control unit (ECU) based on information from various sensors. The ECU precisely specified time passes the drive signal to the solenoid injectors, which means the beginning of the fuel supply. The amount of fuel injected is determined by the period of the opening of the spray gun and system pressure. ECU and sensors of the fuel injection system include: - ECU;
- Speed sensor crankshaft;
- The camshaft position sensor;
- Accelerator pedal position sensor;
- A pressure sensor in the system with a common conduit;
- Coolant temperature sensor;
- The air flow meter.
Based on information from the above sensors and requirements of the driver (accelerator pedal position) ECU determines the instantaneous operating characteristics of the engine and the vehicle as a whole. Unit processes signals generated by the sensors and transmitted on the communication lines, and based on this information, controls the fuel injection system in an open or closed circuit. The frequency of rotation of the crankshaft of the engine measured by the sensor speed of the crankshaft and the camshaft position sensor determines the sequence of fuel injection (phase length). The electrical signal from the accelerator pedal position potentiometer ECU transmits a signal about the degree of the driver pressing the accelerator pedal. Airflow Meter ECU sends a signal to the data with respect to the instant flow of air, which allows the process to calculate the complete combustion with a minimum content of harmful substances in exhaust gases. Because the engine is equipped with a turbocharger and variable boost pressure increase, additional sensor also measures the pressure. At low outside temperatures and a cold engine ECU determines the injection timing and other parameters corresponding to the particular operating conditions. Depending on the vehicle and increasing requirements for safety and comfort for the information transmission ECU additional sensors may be used. The figure shows an example of a diesel 4-cylinder engine with the fuel injection system ?�Common Rail?�.  | Shows the location of the elements does not correspond to their actual location. |
Main functions The main functions of the system are to ensure the required amount of fuel injection in a strictly defined time and at the required pressure. It provides not only a smooth operation of the diesel engine, but also low fuel consumption. Additional functions Additional functions in the operation in a closed circuit and control functions without feedback are used to reduce emissions and fuel consumption, and used to improve the safety, comfort and convenience. For example, exhaust gas recirculation (EGR), charge air pressure adjustment, shifting, electronic immobilizer, etc. CAN system allows communication with other vehicle systems. If the diagnostic check of the car can be extracted data in the reserve system data.
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