用楔横轧机轧制齿轮轴上的齿形时,对影响齿形成形的各种因素进行分析是提高齿形成形质量的关键。基于图像测量原理对齿形进行特征提取,获得齿形离散数据,然后运用数值计算方法最小二乘法把齿形离散数据拟合成齿形曲线,求解出基圆圆心,绘制出齿形。通过数学建模和实验,分析了模具齿形、齿坯相对模具的位置、坯料的初始形状以及轧制温度对成形齿形的影响。结果表明:模具齿形决定轧制成形的齿形,它们的齿廓是一对共轭曲线的关系;坯料相对模具的位置决定齿形的正负变位状态;通过改变坯料的初始形状可以补偿端面附近齿形下凹的成形缺陷;降低轧制温度可以减弱齿顶"拉尖"现象。
As for the teeth on shaft formed by wedge cross rolling,analyzing factors which affect teeth forming is the key to improve the forming quality.Based on the image measurement principle,the teeth characteristics were extracted and data of teeth was obtained.Then a curve was fitted with the teeth data by the method of least square,the workpiece centre can be calculated and teeth contour can be drawn.By analyzing mathematical model and experiments,the conclusions are that the relationship between die tooth profile and workpiece profile is conjugate curve,the position of workpiece makes teeth positive correction or negative,changing workpiece shape can compensate the defect of concave nearly at end area,and decreasing temperature can reduce defect of tooth end tip.