What Does High Pressure Common Rail Mean?

The common rail technology refers to a kind of oil supply method in which the injection pressure is generated and the injection process is completely separated from each other in a closed loop system composed of a high pressure oil pump, a pressure sensor and an ECU, and the high pressure fuel pump delivers the high pressure fuel to the common fuel supply pipe through the high pressure oil pump. The oil pressure in the common fuel supply pipe is precisely controlled, so that the pressure of the high pressure fuel pipe is independent of the engine speed, and the diesel fuel supply pressure can be greatly reduced as the engine speed changes, thereby reducing the defects of the conventional diesel engine. The ECU controls the fuel injection amount of the injector, and the amount of fuel injection depends on the length of the fuel rail (common supply pipe) and the opening time of the solenoid valve.

Refers to a type of diesel fuel injection

The common rail system separates the fuel pressure generation from the fuel injection. If the single pump diesel injection technology is compared to the diesel technology revolution, the common rail can be called a rebellion because it deviates from the traditional diesel system and approximates For sequential gasoline injection systems. Common rail system opens up new ways to reduce diesel engine emissions and noise

Europe can be said to be a paradise for diesel cars, with diesel cars accounting for 39% in Germany. Diesel cars have a history of nearly 70 years, and in the last 10 years it can be said that diesel engines have developed by leaps and bounds. In 1997, Bosch and Mercedes-Benz jointly developed the Common Rail System. Today in Europe, many brands of cars are equipped with common rail diesel engines. For example, Peugeot has HDI common rail diesel engines, Fiat’s JTD engines, and Delphi has developed the Multec DCR diesel common rail system.

Common Rail System Unlike the diesel injection system previously driven by a camshaft, the common rail diesel injection system completely separates the injection pressure generation and injection processes from each other. The solenoid-controlled injector replaces the traditional mechanical injector. The fuel pressure in the fuel rail is generated by a radial piston high-pressure pump. The pressure is independent of the engine speed and can be set freely within a certain range. . The fuel pressure in the common rail is controlled by an electromagnetic pressure regulating valve, which performs continuous pressure regulation according to the working needs of the engine. The electronic control unit acts on the pulse signal of the injector solenoid valve to control the injection process of the fuel. The amount of fuel injected depends on the oil pressure in the fuel rail and the length of time the solenoid valve is open, and the liquid flow characteristics of the injector.

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