基于半约束的开口槽类件的数控渐进成形

CNC incremental forming for open slot part based on half-constraint

针对成形角较大的开口槽类件在渐进成形中厚度减薄严重且难于成形的问题,提出一种基于半约束固定方式的开口槽类件的数控渐进成形方法。该方法采用部分约束方式,仅固定板材的一侧,使非固定侧板料在成形力的作用下向成形区移动,进而增大变形区域和参与变形的板料金属量,以减小板材厚度的减薄幅度。给出了基于半约束固定的开口槽类件的数控渐进成形工艺和成形轨迹规划策略,并以包含有90°成形角的开口槽类件为实验件,进行了全约束与半约束数控渐进成形的对比实验。实验结果表明:在两道次成形策略下,全约束固定方式无法成形出该板材,而半约束固定方式成功成形。其中,成功成形出的零件平均厚度为0.65 mm,最小厚度为0.505 mm,轮廓横向偏差最大为0.62 mm,这说明半约束成形能大大降低板材厚度的减薄率、提高板材的成形性能。

Aiming at the problem that the thickness of open slot parts with large forming angle was severely reduced and it was difficult to form during the incremental forming,a CNC incremental forming method for the open slot part based on the half-constraint fixing method was proposed.In the method,a partial-constraint method was adopted to fix only one side of sheet,so that the sheet material at non-fixed side moved to the forming region under the forming force,thereby the deformation region and the sheet material amount participating in the deformation were increased to reduce the thickness reduction of sheet.The CNC incremental forming process and forming trajectory planning strategy for half-constraint fixed open slot part were given.The comparative experiment of full-constraint CNC incremental forming and half-constraint CNC incremental forming was carried out with the open slot parts containing 90°forming angle as the experimental part.The experimental results show that under the two-pass forming strategy,the full-constraint fixing method cannot form the sheet,while the half-constraint fixing method can form snccessfully.The average thickness of successfully formed part is 0.65 mm,the minimum thickness is 0.505 mm,and the lateral deviation of contour is 0.62 mm,which indicates that the half-constraint forming can greatly reduce the thickness reduction of sheet and improve the sheet formability.