电火花微孔加工中工具电极振动研究

发布时间：2018-03-15 06:19

本文选题：微细加工　切入点：电火花　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：电火花加工可加工任意导电材料,并且在加工过程中工件与工具电极不接触,为非接触加工。微细电火花可加工微型孔及其他形状的微型腔,且加工能力与工件材料的硬度、强度无关。微细电火花加工技术广泛应用在喷油嘴及航空发动机涡轮叶片的微细孔加工和微模具制造上。电火花加工中,工件与工具电极在工作液中达到一定间隙,形成脉冲火花放电,使得工件部分材料熔融、气化,加工过程中工件与工具电极间不存在机械接触力。但是静电吸引力、电磁力、工作液流动冲刷力、放电爆炸力和气泡的膨胀与坍塌带来的反应力等非接触力存在于加工区域中。电火花线切割加工中前述力引起电极丝的振动,影响加工精度。电火花微孔加工中存在同样的问题,但目前很少有文献涉及电火花微孔加工中工具电极的振动问题。本文在现有的卧式微细电火花加工机床的基础上,编制了一套机床数控程序,主要包括坐标显示及原点设定、快速定位、单步进给、工具电极加工、微孔加工、主轴旋转控制、位置探测、停止加工、加工过程信号显示模块,为完成本论文的实验研究奠定了基础。本文基于弹性力学,建立了工具电极振动理论模型,并设计实验验证了模型准确性及实际应用的可行性。实验验证的结果表明,在同一实验条件下,加工15组微孔,有14组微孔的孔径理论计算值和实际测量值差值绝对值在0.25umm到2.56um之间,其相对误差在3%以下；在9组微孔的模型应用性验证实验中,有8组微孔的孔径理论计算值与实际测量值差值绝对值介于O.1lum到2.04um,其相对误差在3%以下；在6组不同实验条件应用性验证实验中,6组微孔的孔径理论计算值与实际测量值差值绝对值介于0.13umm到2.84um,其相对误差均在3%以下。证明了电极振动理论模型的有效性。本文对实验结果对比中的误差原因进行了分析,并探索了不同实验条件下理论模型的可用性。本文亦探索了不同电压、电容等电参数条件对微孔加工中工具电极振动的影响,研究发现工具电极变形幅值随电压增大而增大,随电容增大先变小后变大。
[Abstract]:EDM can process any conductive material and the workpiece during the machining process and tool electrode contact, non-contact processing. Micro cavity micro EDM processing micro hole and other shapes, and the processing ability and the hardness of the workpiece material strength. Micro EDM technology is widely used in the manufacture of micro hole machining the nozzle and gas turbine engine and micro mold. In the process of EDM, workpiece and tool electrode reaches a certain gap in the working liquid, the formation of pulsed spark discharge, the workpiece material gasification melting, workpiece machining process and tool electrode has no mechanical contact force. But the electrostatic attraction, electromagnetic force. The working fluid flow scouring force, expansion force and bubble discharge explosion and collapse as a result of the reaction force of non contact force exists in the processing area. WEDM in the leading force From the vibration of wire electrode, affect the machining accuracy. The same problem exists electric spark micro machining, but there are few literatures involving electrode vibration problems of micro hole machining tool spark electricity. Based on the existing horizontal micro EDM machine tool, developed a NC program, including coordinate and display set origin, rapid positioning, single feed, tool electrode processing, micro machining, spindle rotation control, position detection, processing, signal processing module, which laid the foundation for the experimental research on the completion of this paper. This paper based on elastic mechanics, a tool electrode vibration theory model, and design experiment to verify the feasibility and practical the application of model accuracy. Experimental results show that under the same experimental conditions, processing 15 groups of micropores, there are 14 groups of micropores pore theoretical calculation and actual measurement value The difference in the absolute value of 0.25umm to 2.56um, the relative error is below 3%; in the application of model validation in experiment group 9 in the 8 group of microporous, microporous pore theoretical calculation value of absolute value of difference between O.1lum and 2.04um with the actual measured value, the relative error is below 3%; in the 6 group of different experimental conditions of application to verify the experiment, 6 groups of micropores aperture theoretical calculation value of absolute value of difference between 0.13umm and 2.84um with the measured value, the relative error is below 3%. Demonstrate the effectiveness of the electrode vibration theory model. The cause of error in comparison of the test results were analyzed, and to explore the availability of different theoretical models under the experimental conditions. This paper also explores the influence of different electrical parameters such as voltage, capacitance conditions on tool micro hole machining electrode vibration. The study found that the tool electrode deformation amplitude increases with the voltage increases with increasing capacitance When you get smaller, you get bigger.

【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG661

【共引文献】