基于圆弧刀补偿加工的平面调制切削技术研究

Study on surface perturbation cutting technology based on arc tool with radius offset

针对尖刀加工的平面调制微结构表面质量差以及尖刀顶部尖角易磨损的现象,本文系统分析了尖刀在加工平面调制结构时轮廓误差的形成机理,发现了尖刀加工调制表面的轮廓误差大且存在难以补偿的特性,调制结构的轮廓误差与刀尖宽度成正比,与调制的周幅比值(λ/a)成反比.为此,本文提出了采用圆弧刀具结合刀具半径补偿方法以降低平面调制样品轮廓误差的技术方案.实验结果表明,采用圆弧刀结合刀具补偿方法对平面调制结构的轮廓精度提升具有显著作用,相比于尖刀切削,圆弧刀补偿加工的一维调制样品获得了更高的表面质量和轮廓精度.针对幅值a=4μm,周期λ=60μm的平面调制样品,采用圆弧刀补偿加工方案,调制样品的表面粗糙度Ra值由59.66 nm降至21 nm,轮廓误差精度提高了约20%.

Two issues occur in the machining of planar perturbation structures with a sharp tool,one is that the surface quality is bad,the other is that the sharp angle on the top of the tool is easy to wear.The formation mechanism of profile error and the characteristic of difficult compensation in cutting surface perturbation structure by sharp tool are systematically analyzed.It reveals that the profile error of the structure is directly proportional to the width of the tool tip and the ratio of the perturbation structure.This resulted error is difficult to improve by compensate processing.Therefore,a method is proposed to reduce the cutting profile error of the perturbation structure by using the arc tool combined with the tool radius compensation.The experiment results show that the arc tool combined with the radius compensation method has a significant effect on improving the contour accuracy of the perturbation structure.The surface quality and contour precision of the surface obtained are better than those of cutting by sharp tool.For the sample with the amplitude and period of perturbation patterns being respectively 4μm and 60μm,the Ra value of the surface roughness is reduced from 59.66 nm(using sharp cutting tool)to 21 nm(using arc cutting tool),and the value of the profile error is decreased by 20%.