Development Of Miniature Reciprocating Micro-wedm Equipment And Experimental Research

With the development and maturity of micro electro mechanical system,various fields moving to be precise, diversified and efficient, it has attracted extensive attention from domestic and international enterprise and research institution. For the complicated micro parts made by various materials which micro electro mechanical system needs(such as micro gears, micro steamers, micro motors, micro molds, micro milling cutters, micro sensors, etc.). With the high applicability, low processing cost, good surface quality and high manufacture precision, micro-WEDM is widely employed in this field. Currently, the successfully developed micro-WEDM equipment use uniform moving wire as electrode, cooperated with high-precision multi-axis CNC workbench, can easily machine completed micro parts. However, the famous foreign equipment manufacturers are forbidden to provide any related goods or technology for our nation, so it’s very necessary to develop the micro-WEDM equipment and study its technical rules.On the basis of researching micro-WEDM machining mechanisms, and at the same time, for the purpose of ameliorating the enormous structure, low universality, singleness machining construction of traditional WEDM equipment, an miniature reciprocating micro-WEDM equipment is developed in this thesis. And establishes a mechanical model for the key component wire transport system, this thesis analyzes the influences of wire property, wire bobbin dimension, wire length, etc. on the wire transport system’s stability. In response to that, optimizes and refines the design of wire transport system, and finally completes the manufacture and assembling of micro-WEDM equipment. It can constrain the 50μm micro wire operates steadily, and can adjusting the speed of wire running, also can guarantee it won’t cause excessive vibration and tension distribution, which ensures w ire steadily to reciprocate.Compared with the traditional WEDM, micro-WEDM is stricter in terms of machining precision and surface quality. For this reason, this thesis aims to improve performance of developed equipment. At first, build a mathematical mod el of the key part wire vibration, and by means of solving model solution, analyzes the influence factor of wire vibration, then improves the stability of equipment base on these; Secondly, the basic machining experiments are carried out by using the designed micro-WEDM equipment, The influences of open-circuit voltage, charging capacitor, pulse width on the width of the rotary grooves, the material removal rate and the surface roughness are studied by using single factor experiments, which provides important reference for improving the designed equipment machinability.Based on the fundamental studies above, this thesis designs an experiment of linear-array micro balls with the Central Composite Design(CCD) methods, build a model which considers open-circuit voltage, charging capacitor and the rotational speed of work piece as experiment parameters, and considers the material removal rate and the surface roughness as response values, getting a linear-array micro balls structure with diameter of 200μm, length of 4300μm, finally the technological optimal parameters of machining micro balls are obtained. Then, other complex parts such as 80μm of 4×4 micro array electrode and micro iron tower are machined to prove the further stability and flexibility of designed equipment.