Research On Abrasive Flow Machining Of Precision Oil-passage Of An Electronic Unit Pump

Electric fuel injection(EFI) technology is an effective way to improve the burning performance of diesel engine, and thus enhancing its power performance, reducing the pollution emission and fuel consumption. At present, great progresses of researches on fuel pressure control, fuel injection characteristics, injection timing have been made. However, manufacturing and processing technology of EFI System critical parts still faces with great technical challenges. There are deep holes, micro-holes, and features formed by holes in the EFI System. It’s difficult for traditional manufacturing technologies to polishing this kind of structures. Abrasive Flow Machining(AFM) technology provides a valid method for this challenge.AFM is an efficient precision polishing technique which is used as the last procedure in manufacture processes to achieve a bright and clean surface, and thus improve the characteristics of the parts. There are enormous advantages for AFM comparing with traditional precision machining. However, as a result of particularity of the machining tool, that is the flowable medium, irregularity of the grains, randomness of the grains’ movement, the AFM machining mechanism research process and prediction of AFM machining results are full of challenges and difficulties.In the second place, problems as technological parameter optimization and machining process control have led to unsatisfied surface quality. And the research means of AFM is mainly experiments, which makes the whole work heavy. Under this condition, numerical simulation method of AFM highlights its advantages of economic, efficient and necessity. The numerical method can help to short the research cycle of AFM and predict the machining results.In view of this, the article takes the oil passage of an electronic unit pump as object to carry on the AFM technology research. The results lay a foundation for AFM technology and for critical parts of the EFI System machining technology. So, it’s of theoretical value and practical significance of this task.The main contents of this paper are as follows:Firstly, made clear the knowledge about the characteristics of AFM and its material removal mechanism; Force analysis of the grain have been carried on; corresponding models have been established.Secondly, analyzed the numerical analysis theory of the AFM process; Numerical simulations under all conditions have been carried including different extrusion pressures, velocities, grain sizes, viscosities of the medium and so on.Thirdly, analyzed the influence technological parameters imposed on processing quality and efficient as parameters of abrasive medium, extrusion pressure and processing time and so on. Summarized the corresponding influencing rule. Finally, based on the analysis, found out the optimization scope of the technological parameters. And then, designed a orthogonal table and arranged the numerical simulation based on the theory of orthogonal test. Finally, accomplished the corresponding simulation work and optimized process parameters.