陈浩  黄栋  郭伟科  石卫卫  陈敏 

（广东省科学院智能制造研究所/广东省现代控制技术重点实验室，广东 广州 510075）

摘要：以一种门式精密数控机床的主体结构为研究对象。首先，采用有限元分析法对该机床结构的前四阶模态固有频率和振型进行计算模态分析，得到其前四阶模态固有频率分别为186.04、241.18、321.51、382.51 Hz，并分析了其模态振型变形趋势；然后，通过模态分析试验系统对机床进行试验模态分析，得到机床的前四阶模态固有频率和振型，以及第一阶模态固有频率相对较低，振型为机床前后俯仰运动等结果，与计算模态分析结果一致；最后，计算模态分析与试验模态分析的结果对比表明，横梁与滑枕的配重过大、立柱和主轴箱的结构抗弯能力不足是机床结构的薄弱环节，并针对薄弱环节提出了相应的优化方案，为门式精密数控机床的优化设计及动态特性提升提供了理论参考依据。

关键词：数控机床；计算模态分析；试验模态分析；固有频率；振型

中图分类号：TG659               文献标志码：A           文章编号：1674-2605(2024)06-0012-07

DOI：10.3969/j.issn.1674-2605.2024.06.012                     开放获取

Research on Modal Analysis and Optimize of Portal Precision CNC     Machine Tool Structure

CHEN Hao  HUANG Dong  GUO Weike  SHI Weiwei  CHEN Min

(Institute of Intelligent Manufacturing, Guangdong Academy of Sciences/

Guangdong Key Laboratory of Modern Control Technology, Guangzhou 510070, China)

Abstract: The main structure of a gantry precision CNC machine tool is taken as the research object. Firstly, the finite element analysis method was used to calculate the natural frequencies and modes of the first four modes of the machine tool structure. The natural frequencies of the first four modes were found to be 186.04, 241.18, 321.51, and 382.51 Hz, respectively, and the deformation trend of the modal modes was analyzed; Then, through the modal analysis test system, the machine tool was subjected to experimental modal analysis to obtain the natural frequencies and vibration modes of the first four modes of the machine tool, as well as the relatively low natural frequency and vibration mode of the first mode, which is the forward and backward pitch motion of the machine tool, consistent with the results of the calculated modal analysis; Finally, the comparison between the results of computational modal analysis and experimental modal analysis shows that the excessive weight distribution between the crossbeam and the slider, as well as the insufficient bending resistance of the column and spindle box structure, are the weak links in the machine tool structure. Corresponding optimization schemes have been proposed for these weak links, providing theoretical reference for the optimization design and dynamic characteristic improvement of gantry precision numerical control machine tools.

Keywords: numerical control machine; computational modal analysis; experimental modal analysis; natural frequency; vibration mode