楔横轧轧制成形过程中轧件的滚动半径是楔横轧模具设计和进行工艺分析的基本参数之一,它反映了轧辊与轧件的相对运动关系,对非圆截面轴类零件如发动机凸轮轴等模具辊形曲线设计具有重要影响。通过轧制试验,得到楔横轧轧制过程中轧件滚动半径的变化规律和各种工艺参数的影响规律。结果表明:楔入段轧件滚动半径要大于原始坯料尺寸且随着轧制进行逐渐减小;到展宽段保持稳定;进入轧齐后,随着模具楔面抬高,其值逐渐减小,精整段约等于轧件轧后尺寸。展宽角和成形角越大,轧件滚动半径越大;断面收缩率影响规律比较复杂,当断面收缩率小于一定值时,随断面收缩率增大而增大,当断面收缩率大于一定值时,随断面收缩率增大而减小;坯料直径表现为辊径比越大,轧件滚动半径越靠近原始坯料尺寸内侧;轧制温度对轧件滚动半径的影响较小,而模具楔面刻痕状态影响较大。
Rolling radius of formed part in the rolling procedure of cross wedge rolling is one of the basic parameters for die design and process analysis,which reflects the relationship of relative motion between roll and formed part,so it plays an important role in roller shape curve design of dies for shafts with noncircular cross-section such as the camshaft of engine.By rolling experiment,the variation law of rolling radius during the rolling process is obtained,and the influence rules of technical parameters are achieved.The results show that the rolling radius of formed part is larger than the size of original billet and gradually decreases with rolling process at the knifing stage,and keeps stable during the period of stretching.At the stage of shaping,the rolling radius decreases gradually as the elevation of the mould forming surface.And it basically equals to the final dimension of formed part in the finishing stage.The rolling radius of rolled piece increases with the increment of the tool stretching angle and forming angle.Influence of area reduction is relatively complicated.The rolling radius increases as the area reduction increased at first.When the area reduction raises certain value,it reduces with the rise of area reduction.The diameter of billet shows that the greater the diameter radio of roll to formed part is,the closer the rolling radius to the inner side of original billet size will be.It is found that the influence of rolling temperature on the rolling radius can be ignored,but the condition of notch on the mould has significant effect.