【作者】 陈生华；

【导师】 黄筱调；

【作者基本信息】 南京工业大学 ， 化工过程机械， 2005， 硕士

【摘要】 在机床结构设计中,以现代有限元方法和模态分析理论为支撑的现代设计方法,已经成为现代机床设计发展的必然趋势。本文所研究的高速铣齿机床具有较高的切削速度和较大的切削用量,这就要求设计出的机床具有合理的结构配置和优良的动静态性能。此外,该机床属于单件生产,在图纸设计阶段就必须保证机床的工作性能满足以上的要求。机床在设计初期运用模态分析理论和有限元理论,建立了机床结构的有限元模型。在对有限元模型进行计算的基础上,通过对机床结构的改进使设计出的机床零件及整机具有较高的静刚度和动态特性。这些新技术的研究和应用,对新机床工作性能的改善、加工精度的提高、开发周期的缩短和开发成本的降低无疑是十分重要的。 本文主要工作如下: (1)将基于Pro/E建立机床零件的实体模型导入有限元分析软件ANSYS中。建立了零件的有限元模型,并对其进行了静力计算和模态分析。通过计算,得出初步设计出的机床结构具有较高的静刚度和动态性能。在立柱模态计算中,单元数目的适当增加能够提高固有频率的计算精度。 (2)通过改变立柱内部筋板的布局和厚度来研究其对立柱动态性能的影响。比较ANSYS的计算结果,得出立柱内部筋板的布局和厚度对立柱动态性能有着显著的影响。 (3)完成了机床整机的有限元模型的建立。通过静力计算,得出机床整机的应力和应变云图。与立柱在独立计算时的结果相差4.5%,比较得出整机计算施加的外部载荷简单而且较准确,从而提高计算精度。 (4)建立了机床部分经典结合部的等效动力学模型,并确定了其中的动力学参数。在此基础上,建立了机床整机的有限元动力学模型。通过对机床整机有限元模型的模态分析,得出机床整机的薄弱环节在结合面处,提高结合部的刚度能够有效地提高整机的动态性能。 (5)将有限元分析方法和最优化理论相结合,对机床传动轴进行了优化设计。对于一些结构简单的机床零件,采用该方法能够找到机床零件的最佳结构。更多还原

【Abstract】 The finite element method (FEM) and modal analysis theory are becoming more and more popular in the design of modern machine tools. Because the high-speed gear milling machine discussed here has a high cutting speed and big cutting output, a reasonable machine structure which has better dynamic and static performance should be guaranteed. Furthermore, this machine is a single-piece production, it should have the capability to meet the hereinbefore requirement in the initial design stage. Based on the FEM and modal analysis theory, the paper builds the finite element model of the high-speed gear milling machine. By FEM calculation, the static and dynamic characteristics of the parts and whole machine tool are highly improved. The application of these new methods not only improve the working capability and machining precision of the new machine tool, but also reduce the developing costs of new production and development circle. The main works are as follow:(1) After importing the Pro/E-based entity models to ANSYS, the finite element models are built for static and modal analyses. The calculation results indicate that the more element number applied, the more accurate natural frequency value can be obtained in the modal analysis of upright column.(2) By altering the layout and thickness of the inner ribs, the dynamic characteristics of the upright column are calculated. The calculation results indicate that the two parameters play a significant role on the dynamic performance of the upright column.(3) The finite element model of whole machine tool is built up. By FEM calculation, the results such as the stress and deformation distribution are displayed by ANSYS. The result is 4.5% smaller than that of the single calculation of upright column. By comparing, the calculation of whole machine tool has simple and accurate loads relatively and a more precise calculation result.(4) Some classical dynamic models as well as the characteristic parameters of joining surface are completed. After carrying out the finite element analysis on the dynamic model of the whole machine tool, the calculation results show that the weaknesses of structure are the joining surface. The dynamic performance can be improved obviously by enhancing the rigidity of the joining surface.(5) The structure of drive shaft is optimized by applying FEA and optimization theory. The optimum design of simple parts can be attained in this way.更多还原