摘要
导轨装配的质量直接影响数控机床的直线轴几何精度,为了提升导轨螺栓装配残余预紧力的均匀性,在虑及螺栓交互刚度的基础上,提出了一种残余预紧力变化分析模型及装配工艺优化方法。首先,基于导轨压应力锥形分布假设,构建了不同间距下的导轨螺栓交互刚度函数模型。建立螺栓连接结构的刚度模型,推导出螺栓预紧力变化量与交互刚度值间的映射关系,理论分析得到已预紧螺栓的预紧力变化量与后续螺栓装配间距呈负相关关系。其次,建立某立式加工中心横梁的有限元模型,通过多载荷步仿真分析验证了理论分析结果。最后,对横梁导轨螺栓的装配工艺进行了优化,采用标准偏差与均值的综合评价方法,新工艺下的螺栓残余预紧力离散性降低,一致性提高。
The quality of the guide rail assembly directly affects the geometric accuracy of the linear axis of the CNC machine tool.To enhance the uniformity of the residual preload of the guide rail bolt assembly,an analysis model of the residual preload change and an assembly process optimization method were proposed based on the consideration of bolt interactive stiffness.First,based on the assumption of the conical distribution of the compressive stress of the guide rail,the interactive stiffness function model of the guide rail bolts with different spacing was constructed.The stiffness model of bolted connection structure was established,and the mapping relationship between the change of bolt preload and the interactive stiffness value was derived.The theoretical analysis shows that the change of preload of preload bolts is negatively correlated with the subsequent bolt assembly spacing.Second,the finite element model of a vertical machining center beam was established,and the theoretical analysis results were verified by multi-load step simulation.Finally,the assembly process of beam guide bolts was optimized.The standard deviation and mean value were used to evaluate the residual preload.The dispersion of residual preload was reduced and the consistency was enhanced.
作者
程强
蔡少鹏
张涛
杨聪彬
刘志峰
CHENG Qiang;CAI Shaopeng;ZHANG Tao;YANG Congbin;LIU Zhifeng(Institute of Advanced Manufacturing and Intelligent Technology,Beijing University of Technology,Beijing 100124,China;Beijing Key Laboratory of Advanced Manufacturing Technology,Beijing University of Technology,Beijing 100124,China;Machinery Industry Key Laboratory of Heavy Machine Tool Digital Design and Testing Technology,Beijing University of Technology,Beijing 100124,China)
出处
《北京工业大学学报》
北大核心
2025年第10期1129-1136,共8页
Journal of Beijing University of Technology
关键词
机床
交互刚度
残余预紧力
导轨
螺栓
预紧力
machine tool
interaction stiffness
residual preload
rail
bolt
preload
作者简介
程强(1979-),男,教授,主要从事机床精度保持性与可靠性设计方面的研究,E-mail:chengqiang@bjut.edu.cn。
