基于有限元法的微径铣刀变形分析

Analysis of Micro Diameter Milling Cutters Deflection Based on FEM

文章基于有限元法建立了微径铣刀的欧拉悬臂梁结构动力学模型,求解了不同刀头直径,不同刀头长度和不同刀柄组合的微径铣刀的固有频率,可知随着悬伸长度的减小,固有频率表现出明显的尺度效应。通过计算微径铣刀的振型及变形得知,当悬伸长度相同时,在静态作用力下,随着刀头直径的减小,刀具变形增大;在动态作用力下,刀具变形对微径铣刀的铣削频率和固有频率的平方较敏感,铣削频率离微径铣刀的固有频率越近,刀具变形越大。微径铣刀的动力学变形分析有助于研究微细铣削力、合理选择微细铣削参数、提高铣削过程稳定性,从而获得良好的加工质量。

A structure dynamics finite element model of micro diameter cutter is established based on the Euler cantilever beam in the article.Nature frequencies of different diameters of cutting part with different length of cutter and shank are calculated.Frequencies increases with the overhang length of micro-milling cutter,which shows a size effect phenomenon.Modes and deflection are calculated.The static deflection increases when the cutter diameter decreases with the same overhang length;the amplitude is sensitive to frequencies＇ square items of micro milling cutter in the dynamic condition.The deflection with dynamic force becomes bigger when the milling frequency is close to the nature frequency.This analysis of dynamical deflection of micro-milling cutter provides a basis for studying the micromilling force,selecting the cutting parameters of micro-milling,and improving the stability of milling process,obtaining better surface quality.