• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2018, Vol. 54 ›› Issue (11): 39-48.doi: 10.3901/JME.2018.11.039

• 产品装配技术专栏 • 上一篇    下一篇

基于载荷作用的柔性体三维公差建模及精度影响分析

穆晓凯, 孙清超, 孙克鹏, 孙伟   

  1. 大连理工大学机械工程学院 大连 116024
  • 收稿日期:2017-08-24 修回日期:2017-12-26 出版日期:2018-06-05 发布日期:2018-06-05
  • 通讯作者: 孙伟(通信作者),男,1967年出生,博士,教授,博士研究生导师。主要研究方向为复杂机械装备设计及优化、基于知识的产品数字化设计。E-mail:sunwei@dlut.edu.cn
  • 作者简介:穆晓凯,男,1986年出生,博士研究生。主要研究方向为高端紧固与精密装配技术。E-mail:mxk332@mail.dlut.edu.cn
  • 基金资助:
    国家自然科学基金(51475077)、辽宁省科技重大专项(2015106016)和大连理工大学基本科研业务费(DUT17GF205)资助项目。

Three-dimensional Tolerance Modeling and Precision Analysis of Flexible Body Based on the Assembly Load

MU Xiaokai, SUN Qingchao, SUN Kepeng, SUN Wei   

  1. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024
  • Received:2017-08-24 Revised:2017-12-26 Online:2018-06-05 Published:2018-06-05

摘要: 传统精度设计仅考虑零部件几何公差的影响,未涉及装配载荷作用下零部件变形的影响。为了保证机械系统在工作过程中的可靠性与稳定性,不仅要求在产品设计与制造环节中要严格保证零部件具有良好的设计性能与制造质量,更重要的是保证装配过程中各零部件间的配合性能。以具体的卧式加工中心为例,通过有限元法获取零部件载荷效应下的变形数据信息,结合小位移旋量理论、齐次坐标变换理论及表面认证思想,建立零件载荷变形偏差的综合三维数学模型。分析结果表明:装配载荷作用下的零件变形偏差总体上呈现出传递和累积的趋势,系统末端变形偏差累积量达到-0.024 9 mm。因此,零件载荷变形偏差对机械系统精度的影响不容忽视,设计阶段的三维公差分析应该综合考虑尺寸、形位公差及载荷作用下的变形偏差对机械系统装配精度的影响,才能形成一种面向整机精度的协调与保障机制,为提高复杂精密机械系统的整机性能提供理论与技术支撑。

关键词: 变形偏差, 精密机械系统, 三维公差分析, 装配载荷

Abstract: The traditional precision design only considers the influence of geometric tolerances while not involving the parts deformation of under assembly load. In order to ensure the reliability and stability of mechanical system in the work process, not only to ensure that the parts have a good design performance and manufacturing quality in the process of product design and manufacturing, more important is to ensure the matching performance of the components in the assembly process. It takes a horizontal machining center as an example, the deformation data information of the parts under load effect is obtained by the finite element method. A comprehensive three-dimensional mathematical model for load deformation deviation of the parts is established based on the small displacement torsos theory, the homogeneous coordinate transformation theory and the surface authentication idea. The analysis results show that the deformation deviation of the parts under assembly load displays the trend of transfer and accumulation, and the cumulative deformation deviation at the end of the system reaches -0.024 9 mm. Therefore, the influence of the load deformation deviation on the precision of the mechanical system cannot be neglected. In the design stage of 3D tolerance analysis, the dimension tolerance, the geometric tolerance and the load deformation deviation on the assembly precision of the mechanical system should be considered comprehensively, which will form a mechanism of coordination and protection for the precision of the whole machine, and then to provide theoretical and technical support for improving the overall performance of complex precision mechanical systems.

Key words: 3D tolerance analysis, assembly load, deformation deviation, precise mechanic system

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