立式回转电火花线切割加工电极磨损理论分析

线切割中电极丝的挠曲和断丝问题一直是影响加工精度和加工效率的主要问题,传统的线切割加工电极丝仅仅沿轴线方向快速或者慢速移动,这种磨损是一种不对称的单边磨损.而立式回转丝线切割加工技术,电极丝在轴向往复移动的同时,又在上、下导丝轮的同步带动下绕自身轴线旋转,电极丝整个圆周表面均会发生放电而均匀磨损.文中在理论上对比分析了圆周均匀磨损和单边磨损后电极丝的横截面抗弯惯性矩.结果表明,圆周均匀磨损后的截面抗弯惯性矩大于单边磨损后截面在磨损方向的抗弯惯性矩.因此,立式回转线切割可以提高电极丝的抗弯强度,降低电极丝振动,从而降低断丝现象的发生.

Theoretical Analysis of Wire Wear in Vertical WEDM with Rotation Wire

The flexure and filament breakage of wire electrode in wire electrical discharge machining(hereafter is in short form-WEDM) have always been influencing to the machining precision and machining efficiency. Traditional WEDM wire electrode moves quickly or slowly along the axis, so the wear caused by this movement is unsymmetrically unilateral. However, in Vertical WEDM with Rotation Wire, wire electrode moves forwards and backwards axially, meanwhile, it also rotates around its own axis driven by the upper and low godet wheels. This way the surface of the wire electrode's circle will discharge and the wear is symmetrical. This thesis analyzes theoretically the bending moment of inertia of wire electrode's cross section after comparing the circle's symmetrical wear and the unilateral wear. It turns out that after being worn symmetrically, the bending moment of inertia of the circle's cross section is bigger than that of the circle's cross section after being worn unilaterally in the wear direction. Therefore Vertical WEDM with Rotation Wire can enhance the bending strength of the wire electrode and reduce the vibration of wire electrode so as to prevent the happening of filament breakage.