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Method of Controlling Common Rail Fuel Injection Device

Electronically controlled injector

7/15/2017 8:52 AM
Electronically controlled injector is the most critical and complex component of the common rail fuel system. Its role is based on the control signal from the ECU. By controlling the opening and closing of the solenoid valve, the fuel in the high pressure oil rail is optimized with the best Fuel injection timing, fuel injection and fuel injection rate into the combustion chamber of the diesel engine. In order to achieve a predetermined fuel injection shape, the need for a reasonable optimization of the injector design. The size Common Rail of the control room determines the size of the needle when the sensitivity of the opening, the control room is too large, the needle valve at the end of the injection can not achieve rapid oil off, so that the late fuel atomization; control room volume is too small, Can not give the needle to provide sufficient effective travel, so that the jet process flow resistance increases, so the volume of the control room should also be based on the model of the largest injection of a reasonable choice.

  In addition, the minimum fuel injection pressure of the nozzle depends on the flow rate of the oil return hole and the oil inlet hole and controls the piston face area. In this way, after determining the size of the oil inlet hole, the oil return hole and the control chamber, the stable and shortest fuel injection process of the injector needle valve is fully opened, and the stability Common Rail Injector Valve of the injector is determined. Oil volume. The reduction in the volume of the control chamber can make the response speed of the needle valve faster, so that the fuel temperature on the nozzle fuel injection less impact.

  But the volume of the control room can not be reduced indefinitely, it should be able to ensure that the nozzle needle lift to make the needle fully open. The two control holes determine the dynamic pressure in the control room, thus determining the movement of the needle valve, by carefully adjusting the flow rate of the two holes, can produce the ideal fuel injection law.

  Since the injection pressure of the high pressure common rail injection system is very high, the nozzle hole area of ​​the injector is small. For example, the nozzle diameter of the BOSCH injector is 0.169 mm x 6, and in such a small nozzle diameter and At such a high injection pressure, the fuel flow is in an extremely unstable state, the spray tip angle of the oil bundle becomes larger, the fuel atomization is better, but the penetration distance becomes smaller, so the eddy current intensity of the original diesel engine intake should be changed, Shape to ensure the best combustion process.

  For the injector solenoid valve, the response time of the control solenoid valve should be shortened due to the fact that the common rail system requires a sufficient opening speed, considering that the pre-injection is an important injection mode for improving the performance of the diesel engine. It is 8% higher than the traditional turbocharged diesel engine, 10% lower carbon dioxide emissions, 15% lower noise, completely changed the diesel engine in people's minds, 'noise, black smoke' image. It is 8% higher than the traditional turbocharged diesel engine, 10% lower carbon dioxide emissions, 15% lower noise, completely changed the diesel engine in people's minds, 'noise, black smoke' image. 'Electronic control' refers to the fuel injection system controlled Common Rail Injector by the computer, ECU (commonly known as computer) for each fuel injection nozzle, fuel injection time for precise control, can make the diesel fuel economy and power to achieve the best Balance, while the traditional diesel engine is controlled by the machine, control accuracy can not be guaranteed.

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