Research On Turn-milling Technology For Precision Complex Micro Components

With the rapid development of science and technology,micro systems with high precision have been widely used in more and more fields such as aerospace,energy,weapon and medical devices.Many systems,such as precise micro inertial units,micro motors,and precise micro medical devices,are used in these fields.Precision manufacturing technology is getting more precise,micro and lightening.However,one of the major bottlenecks of the development comes from the processing equipment and technology.Taking considerations of micro components' features,this paper focuses on turn-milling processing technology of precise and micro components,and lays a good foundation for researches on processing micro components with high precision and efficiency.According to micro-cutting requirements of complicated-structured micro components,the overall design scheme of an local-scale reconfigurable turn-milling machine tool on account of the integration of Y axis and B axis is put forward.With the concept of local-scale reconfigurable machine tools,the precise micro turning-milling machine tools are modularized,and the main functional modules,such as milling assembly,numerical control rotary table with two stations,and Y(B)-axis components,are designed and manufactured.The five-axis turning-milling machine tool is manufactured and tested.To verify the capacity of the precise micro turning-milling machine tool,the experimental research with the typical complicated-structured components is carried on.The kinematic model of the micro turning-milling machine tool with modified D–H notation is established,and the form-shaping function matrixes are derived by kinematic and inverse kinematic analysis.The changes of relative location of cutting tools and workpiece are studied and the the motion distribution of the axes is obtained,the kinematic characteristics analysis are also studied.Path planning of cutting tools on precise micro machine tools is studied with Iso-Scallop method.Through the geometric analysis of end mills and the processing surface,the effective cutting radius is obtained,the relationship between effective cutting radius and surface parameters is gained by curvature matching,and the step length is derived though chord deviations,which can largely enhance the processing precision and efficiency,at the same time,lower the cost.A strategy based on decomposing and composing method to recognize and match the processing features of micro components is put forward,which lays a foundation for subsequent processing planning technology.The method to identify the axis with the lowest processing costs is studied with the micro component processing planning strategy based on the cost of processing axis.The processing of non-axisymmetric crankshafts is planned taking the stiffness characteristics into consideration.The topological sort is used in processing planning for micro components,the directed graph based processing scheduling methods is analyzed and the processing procedure of seating micro components is optimized.The flexible lapping of small diameter dead thread is studied.Flexible auto lapping methods are raised,finite element analysis and simulation is also studied.The surface quality of drilling,boring,milling and polishing is analyzed through the experimental research.The regression model of surface quality based on response surface methodology is established,and the best flexible lapping parameters of small diameter dead thread are obtained.