基于残余应力分析的加工中心定位精度保持性研究

Research on Positioning Accuracy Retentivity of Machining Center Based on Residual Stress

基于残余应力分析对加工中心的定位精度保持性进行了研究,提出一种考虑残余应力影响的定位误差分析方法。首先分析了产生残余应力的主要制造工艺环节,采用有限元法对国内某机匣加工中心床身进行了残余应力分析,得出了该床身在铸造与机械加工环节后的残余应力大小及分布情况。在此基础上对残余应力释放后床身-导轨安装基面的变形进行了预测。通过与试验数据的对比,验证了有限元建模的可信性。最后对残余应力释放引起的导轨定位误差进行了计算。

The relationship between residual stress and the positioning accuracy retentivity of machining center was conducted.Then a new method for quantitative analysis of positioning errors caused by residual stress was proposed.Following the analyses of the processes which produced residual stress,residual stress analyses were carried out on a domestic cartridge receiver machining center bed by using finite element method.Thus the distribution of the residual stress of the bed after casting process and machining process was obtained.Then the deformation of the joint surface between the bed and guide was predicted,which was verified by being compared with the actual measurement.Finally,positioning errors caused by residual stress were calculated.