基于机床几何误差模型的数控加工形位误差预测
2019-06-19
作者：李海1，李迎光1，程英豪1，丁岩2
单位：1南京航空航天大学；2齐齐哈尔二机床(集团)有限责任公司
摘要：影响加工形位误差的因素众多，机床几何误差是其中最关键的因素。其影响零件的功能要求、配合性质和自由装配性，是评估机床加工精度的重要指标。本文通过构建机床几何误差和零件形位误差之间的映射关系对加工形位误差预测方法进行研究，建立了基于机床几何误差模型的三轴机床刀具位姿误差模型，并以刀具位姿误差为中间量建立了平面度误差和圆柱度误差预测模型。使用TH6920型镗铣床进行试验验证，与零件形位误差检测值对比，圆柱度预测误差为9.3%，平面度预测误差为4.8%，预测效果较好，验证了预测方法的有效性。
关键词：几何误差；形位误差；刀具位姿误差；加工精度预测
中图分类号：TG806；TH741文献标志码：ADOI：10.3969/j.issn.1000-7008.2019.06.018
Shape and Position Error Prediction for CNC Machining Based on
Geometric Error Model of Machine Tool
Li Hai，Li Yingguang，Cheng Yinghao，Ding Yan
Abstract:The shape and position error as a key index for the machining accuracy evaluation of machine tools，affects the function requirement，fitting property and free assembly of the part.There are many factors that affect the shape and position error of machining，among which the geometric error of machine tools is the most important one.In this paper，a method of shape and position error prediction for CNC machining is studied by building the mapping relation between the geometric error of machine tools and that of parts.The tool pose error model of 3axis machine tools is built based on the geometric error model，and the prediction model of flatness and cylindricity errors is established with the tool pose error as the intermediate variable. The method is verified on a TH6920 boringmilling machine tool.Compared with the measurement value of part shape and position errors，the prediction error of cylinder is 9.3%，and the prediction error of flatness is 48%，which show the effectiveness of the prediction method.
Keywords:geometric error；shape and position error；tool pose error；machining accuracy prediction