Positioning Errors Measurement of CNC Machine Tools Based on J-DBB Method

Applied Sciences

Tao Sun¹  Keqing Lu¹  Haimei Wu¹  Yewen Zhu¹  He Yang¹  Zhanfeng Chen¹  Wen Wang¹  Zhiqian Sang¹  Kaifei Xu¹ 

[1] School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China;

关键词: positioning errors;    full-scale measurement;    machine tool;    double ball bar with a spherical joint;    double ball bar;   

DOI  :  10.3390/app112411770

来源: DOAJ

【 摘 要 】

Due to the errors of the servo system and the errors of the ball screw drive system, the positioning errors inevitably occur in the process of CNC machine tools. The measurement of traditional equipment is limited by a fixed measurement radius and a single degree of freedom, which can only be measured within a fixed plane. In this paper, four different positioning errors of CNC machine tools are first measured at full scale by using J-DBB (a modified double ball bar with one spherical joint connecting two bars) method. The J-DBB device uses a three-degree-of-freedom spherical joint as a connecting part, which realizes that the measurement radius can be continuously changed, and the measurement space is a spatial sphere. First, the principle of the J-DBB method is briefly introduced. Next, four typical positioning errors of CNC machine tools are analyzed and examined, which contain the uniform contraction error of ball screw and linear grating, periodic error of the ball screw and linear grating, interference of measurement devices error, and opposite clearance error. In the end, the trajectories of the CNC machine tool spindle with a single positioning error are simulated by using the J-DBB method. The results reveal that this method can be used for the positioning error of machine tools, which helps to better understand the spatial distribution of CNC machine tool errors and provides guidance for the reasonable selection of working areas to improve the machining accuracy of parts.

【 授权许可】

Unknown