直线导轨矫直与磨削残余应力场的耦合演化机理及协调控制研究

Linear motion guide, as a general function component, is widely used in the CNC and manufacturing equipment. With the rapid development of modern machine tool equipment manufacturing industry in our country, there are higher requirements on the performance and machining precision of the linear guide. Precision straightening with the adjacent precision grinding in the finishing process of linear guide will result in the equalization of residual stress field, leading to size and surface precision of the finished product and a significant reduction in the fatigue performance. Therefore, this project focus on the linear guide in the process of finishing, and study in follows issues: Frist of all, the precise straightening of residual stress field distribution have been obtained after the researches on the evolution mechanism of stress and strain for linear guide under the linear guide rail straightening discrete load point. Secondly, the dynamic characteristic of the linear guide rail grinding system have been analyzed on the residual stress field of straightening as prestressed, and the linear guide coupled nonlinear residual stress field in the finishing process have been discussed . The third, the research aimed at balancing residual stress field of straightening stroke and coordinate matching criterion of grinding allowance. Finally, a consistency model of residual stress field in nonlinear coupling dynamic system of linear guide during the process of processing has been established. The coordinate matching algorithm in finishing process of linear guide is proposed to control effectively the residual stress and lay the theoretical foundation for the machining precision and efficiency of linear guide rail.

滚动直线导轨副是制造装备的核心部件，随着我国机床装备制造业的高速发展，对直线导轨的性能与加工精度提出了更高的要求。在直线导轨的精整过程中，相邻的精密矫直和精密磨削工序会形成非均衡化的残余应力场，导致直线导轨成品的尺寸及表面精度和疲劳性能显著下降。为此，本项目以处于精整过程的直线导轨为研究对象，通过对离散矫直加载点作用下的直线导轨应力应变演化机理的研究，获取直线导轨在精密矫直完成后的残余应力场分布规律，在此基础上，分析将矫直残余应力场作为预应力的直线导轨磨削加工系统的动态特性，讨论直线导轨在精整过程中残余应力场耦合的非线性，研究以有效控制残余应力场为目标的矫直行程与磨削加工余量的协调匹配准则，旨在建立非线性耦合下直线导轨精整过程动态系统的残余应力场一致性模型，提出直线导轨精整过程加工变量的协调匹配算法，为实现直线导轨精整过程的残余应力场均衡化、提高直线导轨的加工精度和效率奠定理论和技术基础。

滚动直线导轨副是制造装备的核心部件，随着我国机床装备制造业的高速发展，对直线导轨的性能与加工精度提出了更高的要求。在直线导轨的精整过程中，相邻的精密矫直和精密磨削工序会形成非均衡化的残余应力场，导致直线导轨成品的尺寸及表面精度和疲劳性能显著下降。为此，本项目以处于精整加工过程中的直线导轨为研究对象，具体研究工作有：（1）研究离散矫直加载点作用下的直线导轨应力应变演化机理，获取直线导轨在精密矫直完成后的残余应力场分布规律。研究表明，矫直应力场沿着工件弹塑性形变法线方向分布，与矫直点的位置、相邻步数的矫直加载相关，表面残余应力分布与矫直行程相关，引入时序因子，描述了直线导轨在精密矫直残余应力场分布规律。（2）研究具有矫直历史的磨削温度场分布状态，分析了将矫直残余应力场作为预应力的直线导轨磨削加工系统的动态特性，用耦合系数来描述直线导轨在精整过程中的矫直与磨削的残余应力场耦合状态。研究表明，矫直残余应力与磨削残余应力的分布状态形式不同，而且数量级也存在一定的不一致性，磨削过程的热-力耦合过程将使矫直残余应力重新分布。初步使用了耦合系数的线性相关性来阐述矫直与磨削残余应力场耦合关系，探索残余应力分布相关性分析。（3）研究以有效控制残余应力场为目标的矫直行程与磨削加工余量的协调匹配准则，建立了非线性耦合下直线导轨精整过程动态系统的残余应力场一致性模型，提出了直线导轨精整过程加工变量及参数的协调匹配算法。研究表明，由于多重矫直加载和磨削热力耦合特性，直线导轨表面残余应力中的拉压应力分布在矫直点两侧，而磨削残余应力分布主要以压应力为主，故在直线导轨精整过程加工变量及参数将以分析矫直拉应力的状态为主，协调匹配参数使磨削表面残余应力保持为压应力。本项目揭示了直线导轨的矫直残余应力场对精密磨削过程的影响，为实现直线导轨精整过程的残余应力场均衡化、提高直线导轨的加工精度和效率奠定理论和技术基础。