【作者】 王玉宝；

【导师】 张大卫；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 结构动态特性是影响数控机床加工效率、精度等性能指标的重要因素,有关数控机床结构动态特性建模、优化和试验技术一直是机床动力学领域的研究热点问题,具有重要学术价值和工程意义。本文针对某型号五轴联动加工中心存在的结构动态特性问题,较深入地开展了机床关键部件滑动结合面动力学参数识别、整机和关键部件有限元建模与仿真、以及结构试验模态分析和结构薄弱环节修改等方面的研究工作。具体工作如下:1)基于立式加工中心工作台,构建了滑动导轨结合面动力学参数实验平台,并通过大量实验,给出了滑动导轨结合面等效参数随润滑、正压力、镶条预紧力等参数变化的基本规律;2)建立了五轴联动加工中心整机和关键部件结构的有限元仿真模型,给出了相应的结构模态振型与参数,以及机床AB双摆头和立柱的基本变形规律;3)借助于LMS Test Lab模态分析系统,进行了机床结构试验模态分析和抗振性切削实验、以及机床立柱进给运动特性分析,提出了机床结构动态特性薄弱环节;4)针对上述机床结构动态特性薄弱环节,提出了相应的结构改进方案,并借助于有限元仿真,验证了结构改进方案的有效性。本文工作是国家科技重大专项“用于钛合金航空结构件加工的五轴联动加工中心”课题的一部分,所提出的机床改进措施已被企业所采用,为提高该机床的结构动态特性奠定了理论与实验基础。更多还原

【Abstract】 As it is of great importance to the machining efficiency and precision of NC machine tools, the study concerning the modeling, optimization and test technique of the structural dynamic characteristic takes an academic value as well as engineering significance. Aiming at the problems about the dynamic characteristic of a certain 5-axis machining center, this paper focuses on the parameter identification of a slide ways contact surface, Ansys modeling and simulation of the machining center and its key component, modal analysis based on experiments together with the structural modification to the weakness. The details of this paper are as follows:1) Based on the table of a vertical machining center, the experiment platform of parameter identification is set up. After plenty of experiments, the law of the equivalent parameters of the guide ways contact surface is obtained when the press, lubrication and the preload of inlaid strips change respectively.2) The finite element model of the 5-axis linkage machining center is built and its modal vibration and parameter are obtained through simulation. Meantime, the law of the upright post and AB axis deformation is acquired.3) By means of LMS Test.Lab, experimental modal analysis, anti-vibration cutting experiment together with motion characteristic analysis of the upright post are conducted to the machining center and the weakness of the structure is found.4) Several structural modification solutions to the weakness of the machining center have been proposed and validated through finite element analysis.The modification proposals have been used by the cooperative enterprise. The work of this paper is part of the subject“5-axis machining center to the machining of the titanium alloy aviation structural products”which belongs to the state project“Major Projects for Science and Technology Development”. It lays the foundation of the theoretical and experimental basis for the dynamic characteristic of the machining center.更多还原