并联机床的动力学特性对加工精度影响的分析

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振动与冲击 ›› 2013, Vol. 32 ›› Issue (16) : 198-204.

论文

并联机床的动力学特性对加工精度影响的分析

许兆棠1, 2，刘远伟1，汪通悦1，吴海兵1

作者信息 +

Effect analysis of dynamic characteristics of a parallel machine tool on machining accuracy

XU Zhao-tang1, 2, LIU Yuan-wei1, WANG Tong-yue1, WU Hai-bing1

Author information +

文章历史 +

摘要

为了提高并联机床的加工精度，分析了并联机床的动力学特性对加工精度的影响。根据牛顿—欧拉方程，得到并联机床的动力学方程，解得连杆的驱动力；根据杆件轴向伸长量与受力之间的关系，得到连杆的长度误差；以无长度误差的连杆长度为优化目标，用优化的方法，得到动平台的位姿，并与连杆有长度误差时动平台的位姿比较，得动平台的位姿误差；根据刀具在动平台坐标系中位置，得刀具加工位置误差及对被加工零件精度的影响。结果表明：并联机床连杆的长度误差，引起刀具加工位置误差，使被加工零件产生形位误差和尺寸误差；并联机床电主轴偏心引起连杆的长度误差的扰动，产生刀具加工位置的扰动误差，影响被加工零件的表面粗糙度。

Abstract

In order to improve machining accuracy of a parallel machine tool, effect of dynamic characteristics of a parallel machine tool on machining accuracy is analysed. Dynamic equation of a parallel machine tool can be obtained by Newton-Euler approach. Drive force of a leg is solved from the dynamic equation. According to relation between axial extension length and drive force of a leg, length error of a leg is calculated. With a leg length of length error-free used as optimization objective, position and pose of a moving platform are got by optimization method. Position error and pose error of a moving platform is obtained by a comparison between the position and pose with length error of a leg and the one without length error of a leg. According to position of a tool in a coordinate system of a moving platform, error of machining position is calculated, effect on accuracy of machined parts is obtained. The result shows that error of machining position of a tool is caused by length error of a leg in a parallel machine tool, which produces form and position and dimension error in a machined part. Disturbed error of machining position of a tool is caused by disturbance of length error of a leg from rotor eccentricity of a parallel machine tool, which effects surface roughness of a machined part.

导出引用

许兆棠;;刘远伟;汪通悦;吴海兵. 并联机床的动力学特性对加工精度影响的分析[J]. 振动与冲击, 2013, 32(16): 198-204

XU Zhao-tang;;LIU Yuan-wei;WANG Tong-yue;WU Hai-bing. Effect analysis of dynamic characteristics of a parallel machine tool on machining accuracy[J]. Journal of Vibration and Shock, 2013, 32(16): 198-204