Overall Design Of High Precision Micro Turn-milling Machine Tool

As micro-miniaturized parts are widely used in the fields of aerospace, nuclear,national defense, automotive and medical instrument industry, there are increasingrequirements for micro manufacturing technology. Micro turn-milling technologydominates in manufacturing field of micro-miniaturized of complex structural parts for theadvantages, as high speed, precision, micro-cutting-force, wide range of machining etc.however, at present, turn-milling machine tools’ motion accuracy is generally low thatcannot meet the processing needs of micro-miniaturized parts.This article focuses on applying macro/micro dual-drive technology to the turn-millingmachine, which can achieve high precision micro-machining. Main researches are asfollows:(1) Overall design of the high precision turn-milling machine toolKinematic models for three different configurations of turn-milling machine tool areestablished based on the theory of kinematics for multi-body system. And the configurationwith the highest precision is chosen. Furthermore, some main function units are chosen,including the high speed precision electric spindle, the B axis turn table, micro stage andthe isolation pillar. The control system and the error compensation method are alsodiscussed.(2) Optimal design of the Y-axisA method of multi-objective optimization driven by the static deformation and mass isproposed. Response surface models, which reflect the relationship between designparameters and structural response outputs, that are static deformation and mass, areconstructed. The goal of getting smaller static deformation and lighter weight is reachedand the Pareto optimal solution set is obtained by the multi-objective genetic algorithm.(3) Error compensation based on the macro/micro dual-drive technologyThe positioning accuracy and the responding characteristic of the micro stage, which isderived by PZT, are measured. A single-axis macro/micro dual-drive system is built.Positioning error compensation using macro/micro dual-drive technology is validated bycomparison between tests with micro stage and experimentations without micro stage. (4) Studies of a submicron tool setting method for micro tool based on the principle ofelectric breakdown in micro gapA tool setting method in machine tool based on the principle of electric breakdown inmicro gap is presented and it’s verified by experiments. Breakdown current-voltage cure ismeasured on the micro double-edged milling cutter. The impacts of the tool diameter andthe tool wear on this tool setting method are analyzed. The results show that this method isstable and the accuracy is submicron. This method also has the advantage of non-contact,simple structure and low cost and is suitable for micro tool setting.