Investigation On Supply Characteristics Of High Pressure Supply Pump For Common Rail System

High pressure common rail system become the main resrarch direction of fuel injection system,because its significant contribution to improve power performance,economical efficience,reduce emission and noise of diesel.The high supply pump as the power element of high pressure common rail system connect high pressure oil and low pressure oil,its fuel supply characteristics impact the overall performance of common rail system and cylinder combustion.Load characteristics affect the accurate control of rail pressure;volume efficiency determine the maximum injection pressure of common rail system;the degree of cavitation affect the volume efficiency and service life of high pressure supply pump,feul delivery consistency affect the rail pressure stability.Researching these problems has great contribution to understand the supply characteristics of high pressure supply pump,design and optimize high pressure supply pump.The structure and principle of high pressure supply pump is analysed in-depth in this paper.Build test bench and calibrate numerical simulation model in AMESim environment.The result show that the simulation model is accurate enough to do simulation analysis and calculation of supply characteristics.Supply characteristics of high pressure supply pump were analysed in-depth with the numerical simulation model.Firstly,load charavteristcs was studied in the typical condition,and explore the influences of different valve parameters on Load characteristics.Secondly,study volume efficiency in whole working condition,and explore the influences of different cam and piston parameters on volume efficiency in the typical condition.Lastly,study the characteristics of the cavity what is measured by the relative density of fuel,study relative density in whole working condition,and explore the influences of different characteristic parameters on relative density of fuel in the typical condition.Feul delivery consistency of high pressure supply pump were analysed in-depth with the numerical simulation model.Firstly,the fuel supply fluctuation phenomenon was described in whole working condition.Secondly,the fuel supply fluctuation mechanism and the influences of different valve parameters on the fuel supply fluctuation were studied at zero capacity,Lastly,the fuel supply fluctuation mechanism and the influences of different structure and control parameters on the fuel supply fluctuation were studied at part capacity.The analyses above provide a theoretical basis to the design and optimization of electronic control injector.