Research on thermal deformation of ultra-precision machine tools with effect on motion accuracy
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摘要: 超大口径超精密机床研制是大口径光学元件加工的必要基础,超大口径超精密机床在大行程、长工作周期的加工过程中,由于导轨发热引起的机床热形变将严重影响运动部件的直线度与光学元件的加工精度。利用ANSYS Workbench软件进行热-结构耦合仿真,对所设计的龙门式大口径磨削机床、5轴柔性气囊抛光机床进行了热形变分析,得到了导轨生热对机床整体热形变的影响规律。针对现有的磨削、抛光机床进行温度-直线度监测实验,探究了热形变对磨削机床所用液体静压导轨与抛光机床所用直线导轨运动直线度的影响规律,实际测量结果表明机床液体静压导轨的油膜生热对导轨运动直线度有较大影响。Abstract: Large-diameter optical component processing is based on the development of super large-diameter ultra-precision machine tools. For super large diameter ultra-precision machine tools, in the process of large stroke and long working time, the machine’s thermal deformation caused by the guide rail's heat will seriously restrict the straightness of the moving parts and the processing accuracy of the optical components. In this paper, thermal-structural coupling simulation is performed by using ANSYS Workbench software to analyze the thermal deformation of the designed gantry-type grinding machine of large diameter and 5-axis flexible airbag polishing machine, the influence of the heat generated from the guide rail is obtained on the overall thermal deformation of the machine. Temperature-straightness monitoring experiments were conducted on existing grinding and polishing machines to investigate the effect of thermal deformation on the straightness of liquid hydrostatic guideways for grinding machines and linear guideways for polishing machines. In practice, the measurement results show a significant impact on the straightness of the rail movement generated by the oil film heat of the machine tool’s liquid hydrostatic guide.
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表 1 横梁静力学仿真结果
滑块编号 正压力/N 动摩擦系数 1 3677.7 0.005 2 1897.9 0.006 3 3847.7 0.005 4 4572.5 0.005 5 1868.9 0.006 6 4546.5 0.005 -
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