Micro-hole Abrasive Flow Polishing Device Design And Technology Research

With the miniaturization of Aero-Space devices, the light trend of high-tech weapons for national defense, and the application of Micro Electro-Mechanical Systems (MEMS) components and different types of civil intelligent detectors, the application of micro-hole parts in manufacturing becomes increasingly widespread, the requirements for machining precision and surface property becomes higher and higher, and the demands for micro-hole ultra-precision machining become more and more urgent. The abrasive flow machining technology, which is a new polishing technology, possesses good surface machining ability, especially suits the ultra-sophisticated machining of various complicated parts of special shape hole, micro-hole and complex internal cavity structures.The thesis first explores abrasive flow polishing mechanism in theory, expounds the properties of micro-hole abrasive flow machining and the motion mode of abrasive grain, and analyzes the mechanical properties and motion properties while the abrasive flow polishing in the cylindrical runner.Then according to the structural features of tested parts, we use GAMBIT software to accomplish the creation of micro-hole abrasive flow polishing model and the partition of grid, and use hydrodynamics software FLUENT to perform 2-d and 3-d numerical simulation on different micro-hole runner shapes to analyze the flowing situation of grinding medium. Through the numerical analysis, we can simulate parameters, such as the static pressure, dynamic pressure, velocity, turbulence kinetic energy, turbulent intensity, effective viscosity, and turbulent viscosity, which provide the theoretical basis for the research into abrasive flow machining technology.On the basis of it, we design micro-hole abrasive flow polishing device, and perform the finite element analysis of hydraulic cylinder, abrasive cylinder and bearing of the device, and then accomplish the development of micro-hole abrasive flow polishing device and the clamp, finish the general design of micro-hole abrasive flow polishing the machine tool on the digit control. It is proved through the polishing experiment that, the design is reasonable and it can meet the needs of micro-hole abrasive flow machining.The experiment uses self-developed abrasive flow polishing liquid to study the finishing ability of abrasive flow machining micro-hole runner surface, explores influencing rules of machining technology parameters, such as the grain size, abrasive thickness, squeezing pressure, machining time, etc. on the micro-hole surface precision. Through testing micro-hole runner surface precision and surface condition before and after abrasive flow machining, it is sure that abrasive flow polishing technology can improve the micro-hole runner surface precision and surface condition to achieve the ideal surface finishing effect. Under the experiment condition chosen in this thesis, the abrasive flow machining parameters for the best surface quality can be achieved.Finally, in order to obtain the best technology parameters combination of abrasive flow machining micro-hole runner surface, we introduce Taguchi experiment design method into micro-hole abrasive flow polishing technology experiment. According to the Taguchi experiment, L9 orthogonal array is projected as experimental platform, and the best technology parameters combination of abrasive flow polishing micro-hole is set up based on the minimizing surface roughness. Through the analysis of signal-to-noise ratio, the influencing order of machining parameters on the micro-hole runner surface precision can be accomplished. The ultimately-obtained best technology parameters which have achieved expected polishing effect can be used to instruct the batch manufacturing of following parts, which provides technology support for the following development and application of digit control abrasive flow polishing machine tool.