工艺参数对楔横轧螺旋齿轴成形的影响

根据楔横轧轧制过程金属体积不变原则,设计固定螺旋升角和变螺旋升角的实验模具,分别用圆坯料和内凹锥坯料在H630楔横轧机上进行梯形螺旋齿轴的轧制实验。研究结果表明:采用圆坯料进行轧制时,易产生轧件齿高不均、螺距不均等缺陷,而内凹圆坯料可以解决齿高不均的问题,最终获得轧制合格齿形的坯料直径经验公式。模具螺旋升角是影响轧件齿形质量的重要参数,模具螺旋升角采用轧件螺旋升角时,轧件齿形端部螺距变大,且出现螺旋痕缺陷。模具螺旋升角选用轧件瞬时直径对应的螺旋升角时,轧件螺距均匀、无螺旋痕缺陷。因此进行楔横轧梯形螺旋齿轴轧制时,选择合适直径的内凹圆锥坯料,采用瞬时变化螺旋升角值,能得到齿形较好的轧件。

Effects of process parameters on forming helical tooth shaft in cross wedge rolling

According to the principle of constant volume in rolling process of cross wedge rolling,the dies characterized by fixed and variable helix angles were designed and made,the experiments of rolling trapezoidal helical teeth shafts with round blank and concave round blank were conducted respectively in H630 cross wedge rolling mill.The results show that rolling in round blank is apt to produce workpieces with defects such as uneven height of teeth and uneven pitch,while rolling in concave round blank can solve the problem of uneven height of teeth.The empirical formula of the ideal diameter for blank rolling is obtained.The helix angle of die is an important parameter influencing tooth quality.The pitches of tooth ends enlarge and the helical mark defects occur when the constant helix angle of the die is equal to that of the workpiece is adopted.When the helix angle is equal to the corresponding angle of instantaneous rolling diameter,the pitch of the workpiece is even and the helical mark defect is improved.Therefore,when rolling helical shafts are in cross wedge rolling,the workpiece with better tooth profile can be obtained with chosen concave cone blank of appropriate diameter and instantaneous helix angle of the die.