中文摘要：

龙门镗铣床的床身X轴与横梁Y轴垂直度误差是其坐标垂直度误差的主要方面。对其影响因素进行分析后发现横梁导轨的不均匀磨损会增大横梁导轨的直线度和上下导轨的平行度误差,从而严重影响镗铣床坐标垂直度误差。为防止此种情况产生,从横梁的结构和装配工艺两方面对其进行研究。发现横梁的不等高导轨结构可防止不均匀磨损使上下导轨受力均匀,通过有限元仿真分析得到了横梁导轨安装基面的最佳高度差。对实际装配工艺产生的垂直度误差进行计算,发现装配工艺可能导致机床坐标垂直度误差超差,降低导轨寿命。最后给出了改进建议。

英文摘要：

Perpendicularity error of gantry milling - boring machining center lathe bed X axis and vertical beams Y axis is the main aspect of perpendicularity error. To analyze the influence factors and find that uneven wear of beam guide increases straightness error and parallel degree error, thus affect the perpendicularity error of the machine. To prevent the situation, the paper does the research of two aspects of the struc- ture and assembly process of the beam. Unequal - high beam makes the upper and lower guide rail force uniformly, the best height difference of beam guide rail installation base surface is obtained by simula- tion analysis. The perpendicularity error caused by the actual assembly process is calculated, find that the assembly process leads to perpendicularity out - of - error of machine tool, the guide rail life is re- duced. Finally suggestions for improvement are given.