大径厚比带轮筒壁铲旋成形缺陷形成机理

Study on forming mechanism of defects in boss forming of belt pulley cylinder with large diameter-thickness radio

采用有限元模拟方法分析大径厚比带轮筒壁铲旋成形过程,对成形过程中变形区域材料流动距离长、变形程度剧烈、易出现带轮筒壁欠肉及筒壁表面隆起等缺陷的形成机理进行研究。结果表明,带轮直筒壁上端部欠肉,是由于材料变形处于自由变形状态所致;筒壁内壁表面欠肉和外壁表面隆起,则是旋轮圆角半径、进给速度、摩擦条件等多种因素共同作用的结果。提出了相应的解决措施,并在CDC-400旋压机上进行试验,验证了数值模拟结果和解决措施的有效性。

In boss forming of belt pulley cylinder with large diameter-thickness radio ,the flow distance of metal materials in de-formation area is long and the deformation is severe .The defects such as shrinkage of metal and surface uplift at the cylinder are prone to occur .In this study ,the forming mechanisms of these defects were investigated by finite element simulation .Free de-formation of metal at the top cylinder of belt pulley caused the shrinkage .The shrinkage of metal at the inner wall and the surface uplift were the result of joint influence of the roller roundness radii ,the roller feed velocity and the friction conditions .Some measures were proposed to avoid these flaws .A corresponding experiment was done with the CDC-400 spinning machine to vali-date the numerical simulation and those measures .