Research on Time Element-Period Threshold Algorithm for High Pressure Common Rail Fuel System

High pressure common rail fuel injection system(HPCRFIS) is widely used in diesel engines. How to control the pressure stability of the injection system and improve the fuel injection accuracy is a research hotspot. In this paper, a control algorithm considering the opening time of high pressure common rail fuel inlet valve and the opening cycle of injection system needle valve is proposed (time microelement -- period threshold algorithm). The cam lift model of high-pressure fuel inlet system, the oil pressure model of plunger chamber, the needle valve movement model of injection system and the physical model of high-pressure fuel pipe are established respectively. The opening time of the injection valve considering the opening cycle of the injection system needle valve was calculated by using C language programming and dichotomy. Through the coordinated control of the inlet valve of the high pressure pipeline and the needle valve of the injection system, the pressure of the high pressure pipeline injection system is stabilized within the precise pressure range required by the diesel engine oil supply system. Finally, MATLAB simulation software is used to verify the accuracy of the time microelement - period threshold algorithm.