电火花线切割加工中电极丝空间温度分布建模  

The Spatial Temperature Distribution of Wire Electrode in Precise WEDM

作　　者：陆程[1] 沈娣丽[1] 陈志[2] 明五一[2] 

机构地区：[1]中州大学工程技术学院,河南郑州450015 [2]华中科技大学机械科学与工程学院,湖北武汉430074

出　　处：《机械设计与制造》2015年第4期120-122,125,共4页Machinery Design & Manufacture

基　　金：国家自然科学基金资助项目(51175207)

摘　　要：在电火花线切割加工中,由于剧烈的放电过程,放电通道内的电极丝温度会迅速升高,且非常不均衡。电极丝温度不均衡将增加电极丝内部的热应力,改变其物理化学性能,空间温度分布会直接影响电极丝的断丝和运动特性等。从机理出发,根据傅里叶热传导定律,对放电通道内的电极丝进行微元(dz)热平衡分析,建立导轮间电极丝的空间温度分布的微分模型,并求出放电通道内和放电通道外电极丝温度升高的理论解。进一步结合实际加工情况,计算出电极丝温度升高的数值,最后总结了走丝速度、放电电流和放电频率对电极丝空间温度升高的影响规律,为以后研究由温度升高引起的电极丝断丝机理和运动特性(挠曲变形和振动)提供理论基础。In the Wire Electrical Discharge Machining（WEDM）, the temperature of wire electrode in the discharge channel rises rapidly due to violent electrical discharge, and it is very unbalance. The wire temperature increment will lead to the increase of thermal stress of wire electrode, and the spatial temperature distribution directly impacts the characteristic of wire rupture and movement. First of all, the thermal equilibrium analysis of wire infinitesimal was carried out based on Fourier heat equation. Secondly, a model of spatial temperature distribution of wire electrode in discharge channel was built, and the temperature increment＇s theory resolution of wire electrode in both inside and outside of discharge channel was derived out. Furthermore, the value of wire temperature increment was calculated out by combining the actual process, Eventually, the influence rules of wire speed, discharge current and discharge frequency on wire spatial temperature was summarized, and they can provide theoretical basis for studving the wire rupture and movement characteristic due to temperature increment.

关 键 词：电火花线切割 电极丝 温度分布 热应力 傅里叶热传导定律 

分 类 号：TH16[机械工程—机械制造及自动化] TG661[金属学及工艺—金属切削加工及机床]