机床支承件螺栓连接布局设计方法研究

Bolted Connections Layout Design for Machine Tool Support Part

针对机床支承件螺栓连接布局设计缺乏相关技术理论支撑的问题,提出了考虑压力分布耦合作用的螺栓连接布局优化设计方法。该方法基于高斯函数,通过数据拟合方法对单螺栓连接结合面压力分布进行数学表征,引入单螺栓极限作用半径的概念,表征单螺栓连接结合面压力分布区域的大小,研究单螺栓极限作用半径的确定方法,并通过分析螺栓间压力分布的耦合作用对其进行修正,以修正后的极限作用半径为依据,建立机床支承件螺栓连接布局优化设计方法。构建机床典型支承件微缩模型,通过有限元分析和试验的方法验证模型的可行性,依据此模型在动刚度和静刚度两方面校验螺栓布局设计方法。研究结果表明,该设计方法使机床动刚度一阶固有频率最大提高了13.86%,静刚度最大提高了18.16%,有效改善了机床整体的动静特性,将为机床支承件螺栓连接布局设计提供基础理论与技术支持。

A novel optimization design method considering coupling of pressure distribution is proposed to provide theoretical support to the bolted connections layout design of machine tool support part.The data fitting method is used to characterize the pressure distribution on the interface of single bolt based on Gaussian function.The region of pressure distribution is represented by the ultimate impact radius of single bolt.The ultimate impact radius is corrected by the coupling of pressure distribution.The design schedule of bolted connections layout is established according to the corrected radius.This method is verified with a micro model of a real machine tool by analyzing the static and dynamic rigidity,and the feasibility of the micro model is confirmed by FEM and experiments.It is concluded that the maximum optimum reaches 13.86%in the first-order natural frequency of dynamic rigidity,and 18.16%in the static rigidity,and the static and dynamic performances of the machine tool can be effectively improved.