Study On A New Fuel Injection Technology-FAI

The essential part of fuel injection system is the injector. The study is based on the theory of FAI(Finely Atomized Injection) and develops a fuel injection technology that can be fit for PI system and DISI system at the same time. Further studies are carried out on the industrialization of the FAI technology for small gasoline engine and a new fuel injection system is established.Firstly, the fundamental working principle of MFUD0007 (which is one type of the FAI injectors) is presented as an example. The performance test method of FAI injectors is developed and the FAI injection characteristic is studied by the method of experiments for the first time.The mechanisms of Dissipation of Production (DOP) are studied and the concept DOP of is presented during the study on the consistency of FAI injectors. Then, the fuel flux measured method and non-linear error control method are presented to ensure the consistency of the fuel injection unit. The statistical analysis results on DOP show that the deviation of the fuel flux brought out by DOP may be up to 10% and the control method to DOP is effective. A systemicly study on the reliability of the FAI fuel unit and ECU is carried out for the first time. After analyzing possible reasons for failure in the FAI fuel unit and ECU, the technology with the piston separated from armature is introduced, and the mechanical analysis of the piston shows that the force and torque of the piston acting on the pressure cavity are almost decreased by one half. An experiment is planned to test the reliability of the FAI fuel unit and ECU. Some facilities, such as fuel test complex, fuel unit grinding equipment and injection rule test apparatus, are developed. The test on the technology with the piston separated from armature show that it can be up to more stable. One conclusion is discovered; the lengthening of the axis of the pressure cavity can prolong the life of the FAI fuel unit.The FAI Development system was developed for the developing and application of the FAI technology. During software programming, the object-oriented method and 32-bit technique of WINODWS are used. The hardware consists of HIL hardware (hardware in the loop) and the High-Speed-Acquisition Card.The SFP0002 system of FAI is given as an example. SFP0002 is designed for two wheelers under 150cc and a control strategy is designed for it. The CG125 engine equipped with SFP0002 is tested on a strength condition. The test results show that it can easily pass emission limits, and it can also match the requirements of a 10000km road test.