Research On Control Characteristics Of High Pressure Fuel Injector And Design Of Driving Circuit

With the development of Automobile industry, direct injection technology is more and more used in automobile fuel injection system, and the high-pressure fuel injector is the core component of direct injection technology. It has a flexible and precise control method, as well as great advantages in environmental protection and fuel economy. Both of them favored by people. The working conditions of high-pressure fuel injector directly affects the overall performance of automobile engine, utilization ratio of fuel oil and emission of vehicle exhaust pollutants.This paper firstly introduces the structure and working principle of high-pressure fuel injector, analyzing the characteristics of high-pressure fuel injector control signal, which is composed of main pulse and PWM wave. Then combined with the characteristics of its internal structure and working principle, the mathematical model of high-pressure fuel injector is established. The relationship between the time and voltage in the process of the injector opening is derived. Then using AMESim hydraulic simulation software designed high-pressure injectors simulation model, combining the characteristics of internal coil varying current in the open process. The paper analyses the influence of different turn-on voltage to the high-pressure fuel injector’s opening speed and power consumption in detail.Secondly, this paper also designed high-pressure fuel injector drive system. According to the system design requirements and programs, turn-on voltage and pulse width adjustable drive circuit design is accomplished. The test results of this drive circuit meet the initial requirements of the system design, which can control the high-pressure fuel injector to inject sequentially. In line with the actual working condition of the automobile engine, it provides a test platform for the actual function of the high-pressure injectors.Finally, the research does the control experiments of the high-pressure fuel injectors in the laboratory, and records a large number of experimental data and test waveform. Based on the measured data and waveform analysis, it proves the correctness of the theory simulation and the reliability of the high-pressure injector drive system.