The Design Of Micro-milling Machine And Simulation Analysis Of Key Unit

With the development of science and technology, the rising demand of kinds of small-sized optic-mechanical components gradually becomes a trend, they are used more widely in the high technology field of defence and military, life science, aerospace and microelectronics. These demands require small-sized optic-mechanical components not only have small size, high-precision surface, but more specific shape characteristic. Under this kind of trend, microfabrication technology is gradually concerned by academia and project circle. In comparison with other microfabrication methods,micro milling has the high processing efficiency, can realize 3d and no environmental pollution processing, thus becomes an important processing mean. Precision milling machine is the premise and basis of micro milling, this paper is going to research the design and analysis of a micro milling machine.The paper firstly analyzes the development and present situation of the microfabrication technology at home and abroad. On this basis, according to the corresponding parameter's demands, carry out the overall scheme design of the micro milling machine. As the core control unit, PMAC control servo motor to drive ball screw vice to realize precision linear motion, then realize the XOY workbench precision linear movement. The Z axis linear motion is realized by a single moving workbench, and the control principle is in the same way with the XOY's, and finally achieve the three axis linkage. The rotation movement of spindle is also provided by PMAC. Linear motion can realize accurate position through the grating measuring system which supplies position feedback.This paper mainly to design and analysis the micro milling machine, mainly contain the design of spindle system and gantry frame, and the choose of their material. On the basis, the paper analysis and research the spindle unit structure, bearing assembly mode, check the strength and stiffness of the spindle and get that the design meets the design requirements. By using Catia software this paper mold the spindle and gantry, then mesh it with Hypermesh. On the Base, apply boundary conditons and load ,then carry on the static analysis the spindle and gantry frame, get the stress and strain of them, and we conclude that the biggest stress which is smaller than the allowable stress, so the designed structure meet the design requirements. Through the dynamic analysis, this paper research the mode shape of the spindle unit and frame, get their main mode shape and frequency, which provide the basis for the assessment and prediction of static and dynamic characteristics of the micro milling machine.Based on the analysisi above, this paper makes a virtual assembly of the micro milling machine designed and a kinematics analysis according to the actual working conditions. This paper takes the friction calculated between the relevant motion units as the main resistance, then takes this resistance and milling force as the constraint conditions of actual working condition of simulation analysis, by changing the motor speed analyzes and studies the torque and power of the motor. Through contrasting the maximum torque and power with the rated torque and power we can judge whether the selection motor meet the design requirements. Then the paper extracts the rules of motor torque and power along the motor speed and analyzes them. These data provide a theoretical guarantee for the normal operation and a theoretical basis for the choosing of some parts.