作者：王斌

作者单位：核工业理化工程研究院, 天津 300180

关键词：三坐标测量机;薄壁件;温度补偿;测量变形;测量精度

摘要：

为提高三坐标测量机在测量一种U型截面薄壁件时的测量精度，分别从温度和测量力两方面研究精度优化方法。基于物体热膨胀效应的原子热振动原理分析铝合金材料的热膨胀影响因素，将温度影响引入测量能力评估算法，得到可实施温度补偿的边界条件，利用Minitab对变温测量实验数据进行分析并拟合出该薄壁件在径向方向上的热膨胀函数，实现在温度边界范围内对测量结果进行精度优化；针对RDS XXT测头系统的内部构造，通过对测头结构进行力学分析并建立采点触发力学模型，确定该测头系统的采点触发模式为力矩触发，利用材料力学理论分析力矩触发模式下的被测件形变机理。测力及测量截面位置交叉测量实验结果表明：测杆长度越长，测力越小，且越靠近工件底部，测量误差越小，测量精度越高。

Measurement accuracy optimization method study of the thin wall piece with U shape section
WANG Bin
Research Institute of Physical and Chemical Engineering of Nuclear Industry, Tianjin 300180, China
Abstract: In order to improve the measurement accuracy of thin wall piece with U shape section by CMM, the precision optimization method is studied from two aspects of temperature and measuring force respectively. Based on the principle of atomic thermal vibration, the influence factors of thermal expansion of aluminum alloy materials are analyzed, the temperature influence is introduced into the measurement capability evaluation algorithm, the boundary conditions of temperature compensation can be implemented, the experimental data of variable temperature measurement are analyzed by Minitab, and the thermal expansion function of the thin-walled parts in radial direction is fitted. The temperature compensation of the measurement results can be realized within the temperature boundary range. Aiming at the internal structure of the RDS XXT probe system, through the mechanical analysis of the probe structure and the establishment of the mining point trigger mechanical model, it is determined that the picking point trigger mode of the probe system is torque trigger. Based on the theory of material mechanics, the deformation mechanism of the measured parts under the torque trigger mode is analyzed, and the experimental results show that the measurement accuracy can be improved effectively by selecting the length of the measuring rod and measuring the height of the cross section reasonably.
Keywords: CMM;thin wall piece;temperature compensation;measuring deformation;measurement accuracy
2019, 45(9):21-26  收稿日期: 2019-03-11;收到修改稿日期: 2019-05-08
基金项目:
作者简介: 王斌(1982-),男,天津市人,高级工程师,硕士,研究方向为精密测试技术
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