【作者】 李俊烨；

【导师】 刘薇娜；

【作者基本信息】 长春理工大学 ， 机械制造及其自动化， 2011， 博士

【摘要】 随着航空航天器件的微型化,国防高技术武器的轻型化,微机电系统元件及民用各类型智能探测器的应用,微小孔零件在制造业中应用越来越广泛,加工精度及表面性能要求越来越高,对微小孔超精密加工的需求越来越迫切。磨粒流加工这一新的抛光加工工艺具有良好的表面精加工能力,特别适合于各类复杂异型孔零件、微小孔、复杂内部型腔结构的超精密加工。本文首先在理论上对磨粒流抛光机理进行了探讨,对微小孔磨粒流加工特性及磨粒的运动方式进行了分析,并对磨粒流在圆柱形流道内抛光的力学特性和运动特性进行了分析。然后根据试验零件的结构特征,应用GAMBIT软件完成了微小孔磨粒流抛光模型的创建和网格划分工作,利用流体力学软件FLUENT针对不同微小孔流道形状进行二维及三维数值模拟来分析研磨介质的流动状况。通过数值分析,可模拟研磨介质的静态压强、动态压强、速度、湍流动能、湍流强度、有效粘度和湍流粘度等参数,为磨粒流加工工艺研究提供理论依据。在此基础上设计了微小孔磨粒流抛光装置并对装置的液压缸、磨料缸及其支座进行了有限元分析,进而完成了微小孔磨粒流抛光装置及其夹具的研制以及数控微小孔磨粒流抛光机床的总体设计工作。通过抛光实验证实,该装置设计合理,可满足微小孔磨粒流加工的需要。以自行研制的磨粒流抛光液对磨粒流加工微小孔流道表面的精加工能力进行研究,探讨了磨粒粒度、磨料浓度、挤压压力及加工时间等加工工艺参数对微小孔表面精度的影响规律。通过对磨粒流加工前后微小孔流道表面精度和表面形貌的检测,可以确信磨粒流抛光技术确实可以显著改善微小孔流道的表面精度和表面形貌,获得理想的表面精修效果。在本文所选定的实验条件下,得到了最佳表面质量的磨粒流加工工艺参数。最后,为了获得磨粒流加工微小孔流道表面最佳工艺参数组合,将田口实验设计法引入微小孔磨粒流抛光工艺实验。用田口实验规划L9正交表为实验平台,以表面粗糙度为望小型期望目标确定了磨粒流抛光微小孔最佳工艺参数组合。通过对信噪比的分析,获得了各加工参数对微小孔流道表面精度的影响次序。最终获得的达到预期抛光效果的最佳工艺参数,可用于指导后续零件的批量生产,为数控磨粒流抛光机床的研发和磨粒流抛光技术的应用提供了技术支持。更多还原

【Abstract】 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.更多还原