数控机床床身热变形临界点确定方法及应用  

Determination method of thermal deformation critical point of CNC machine tool bed and its application

作　　者：杨洪涛[1] 陈邦晟 李莉 庞勇军 张铈岱 YANG Hongtao;CHEN Bangsheng;LI Li;PANG Yongjun;ZHANG Shidai(School of Mechanical Engineering,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学机械工程学院,安徽淮南232001

出　　处：《合肥工业大学学报（自然科学版）》2018年第10期1331-1335,共5页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(51675004)

摘　　要：文章分析了机床床身热变形与光栅测量误差之间的相关性,提出了机床床身光栅安装线上单向热变形临界点概念和利用热变形临界点安装光栅的方法,研究了基于有限元分析的热变形临界点理论确定方法,用于确定床身单向热变形临界点位置,进而建立高精度的光栅测量系统误差补偿模型;为了验证该模型的有效性,搭建了实验装置进行机床热变形临界点的实测实验。实验结果分析表明,利用该确定方法确定的热变形临界点位置与实验确定的位置相差2.5mm,对光栅零位误差预测值影响仅0.1μm,对光栅示值误差预测值影响仅0.2μm。因此该确定方法可以确定实际机床的床身热变形临界点,并为后续不同结构的数控机床床身单向热变形临界点的确定、床身热变形误差附加影响的消除提供了一定的参考。This paper analyzed the correlation between the thermal deformation of machine tool bed and the measurement error of the grating.The concept of unidirectional thermal deformation critical point on grating mounting line of machine tool bed and a new grating installing method by using thermal deformation critical point were studied.A theoretical determination method of the thermal deformation critical point based on finite element analysis was proposed,which was applied to determining the position of the thermal deformation critical point of the bed miniature.Then a high precision error compensation model of grating measurement system was established.In order to verify the effectiveness of the determination method,a practical experiment device was built to measure the actual position of thermal deformation critical point.The analysis of the experimental results shows that the difference between the thermal deformation critical point positions obtained by the theoretical determination method and determined by the experimental method is 2.5 mm,which can only generate 0.1μm predictive value of grating zero error and 0.2μm predictive value of grating indication error.So the studied theoretical determination method can be used to determine the thermal deformation critical point of actual machine tool bed,which provides reference for the determination of unidirectional thermal deformation critical point of the CNC machine tool bed with different structures as well as the elimination of additional effect of thermal deformation error on the grating measurement system.

关 键 词：数控机床 光栅测量系统 热变形临界点 确定方法 误差建模 

分 类 号：TG659[金属学及工艺—金属切削加工及机床]