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High pressure common rail system for diesel engine

Author: Site Editor     Publish Time: 2020-10-28      Origin: Site

Advantages of diesel engine

Fuel consumption is lower than that of gasoline generators. The thermal efficiency of diesel generators can reach 30% to 45%, and that of gasoline engines is 25% to 30%.

Low emissions, the emissions of hydrocarbons, carbon monoxide and carbon dioxide are lower than gasoline vehicles.

High power, high torque, low failure rate and long life.

diesel car

High pressure common rail system for diesel engine

The fuel injection device can be regarded as the heart of the engine. It largely determines the injection time, injection volume, whether the fuel can be completely atomized, and whether it can be completely burned.

The high-pressure common rail system completely separates the generation of injection pressure and the injection process. The high-pressure fuel pump sends the pressurized fuel into the high-pressure fuel rail. The high-pressure fuel rail is connected to the injectors of each cylinder. The operation of the fuel injectors is electronically controlled(ECU) control.

diesel engine


Fuel rail

Store the pressurized fuel pressure delivered from the fuel transfer pump, and then distribute the fuel to the injectors of each cylinder.

Pressure limiter

If the pressure in the fuel rail is abnormal, open the fuel limit valve to release the pressure.

Fuel rail pressure sensor

Detect the fuel pressure in the fuel rail.


Flow buffer

Reduce the fuel pressure pulsation in the fuel rail. If the fuel flows out excessively, the flow buffer will close the fuel passage to prevent more fuel from flowing out.

Work process

The fuel is sucked out by the fuel pump from the fuel tank, and then delivered to the suction mechanism through the positive crankcase ventilation(PCV). The PCV adjusts the amount of fuel sucked by the suction mechanism to the necessary discharge amount, and then the fuel is pressured to the oil through the delivery valve rail. The fuel delivered from the fuel intake pump is sucked by the plunger. In order to adjust the fuel rail pressure, PCV controls the emissions. Because the pressure of the fuel pump is relatively high, a fuel pressure regulator is also needed to send excess fuel from the return pipe to the fuel tank.

The requirements of diesel engine for fuel injection system

Freely control injection pressure

In the electronically controlled fuel injection system, the fuel injection pressure can be controlled relatively freely. The degree of fuel atomization determines whether the fuel can be efficiently used and combusted. A good atomization effect depends on higher fuel injection pressure. 

Injection timing

When the diesel engine starts, runs at full load and at high speed, the timing of fuel injection into the cylinder is very important. Because when the diesel engine is started, it is best to inject fuel at or close to the top dead center. At this time, the air in the combustion chamber is the hottest and easy to catch fire. After the diesel engine is started, at high-speed operation, the fuel injection time must be advanced to compensate for injection lag, ignition lag, and other factors that affect combustion in the cylinder.

Measurement of fuel injection

The fuel injection system must accurately determine the amount of fuel supplied to the diesel engine. Since the fuel requirement of a diesel engine changes greatly from low speed to high speed, the fuel injection system should meet the fuel requirement of different working conditions.


Rapid control of start and end injection

Diesel fuel injection must start and end quickly. If the fuel injection starts to lag, it will change the timing of the fuel pump to the diesel engine, causing difficulty in starting and poor operation; if the injection is lagging, it will cause exhaust fumes and irregular exhaust noise.

The common rail system is one of the most sustainable fuel injection systems due to its unique advantages. The high-pressure common rail system realizes the separation of pressure build-up and injection process, so that the control process is more flexible, can more accurately realize the precise control of small oil volume, and better realize multiple injections.

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HENSHINE PRECISION Machinery Co.,Ltd.was established in 2012,and it is high-tech enterprise which is professional diesel engine Valve and industrial hydraulic valve research,development,
Manufacturing and sales.Themain research direction:Diesel common rail suction control valve(SCV),




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