花键冷滚打成形表层残余应力分布规律研究

为提高冷滚打成形花键的表层性能，以渐开线花键为研究对象，采用轮廓法进行冷滚打花键残余应力空间分布测量。对实验结果进行分析，研究冷滚打成形参数对花键齿廓齿根、分度圆和齿顶处残余应力分布规律以及残余压应力层深度分布规律的影响。结果表明：冷滚打花键的齿廓表层是残余压应力，分度圆处表层深度为0.35～0.45 mm的残余压应力较大；齿根处形成的残余压应力高于分度圆处和齿顶处的残余压应力，齿顶处形成的残余压应力值最小；冷滚打转速增大引起冷滚打花键齿廓表层残余压应力峰值的增加和残余压应力层深的下降，花键进给量增加使得花键齿廓表层残余压应力峰值和残余压应力层深增加；分度圆处残余压应力层深度达到0.68～ 0.98 mm，残 余压应力峰值达到67.4～80.8 MPa.

Research on Distribution Law of Residual Stress in Surface Layer of Cold Roll-beating Spline

The involute spline is studied to improve the surface quality of a spline.The contour method is used to determine the spatial distribution of residual stress during cold roll-beating,and the experimental results are analyzed.The effects of cold roll-beating forming parameters on the distribution of residual stresses and the depth distribution of residual compressive stress at the dedendum,the reference circle and the addendum of spline tooth profile formed by cold roll-beating are studied.The result shows that the surface layer of tooth profile during cold roll-beating has residual compressive stress on it,which is the highest when the depth of spline tooth profile at reference circle reaches at 0.35-0.45 mm.The residual compressive stress at the dedendum is higher than those at reference circle and addendum,and the residual compressive stress at the addendum is the smallest.The increase in the rotational speed can lead to the increase in the peak value of residual compressive stress and the reduction in the depth of residual compressive stress layer of tooth profile of cold roll-beating spline shaft.The increase in the feed rate can lead to the increase in the peak value of residual compressive stress and the layer depth of a tooth profile of cold roll-beating spline.At reference circle the layer depth of residual compressive stress is 0.68 ～0.98 mm,and the stress peak value is 67.4 ～ 80.8 MPa.