马鞍形板材件多点“三明治”成形实验研究

Experimental research on the saddle workpiece by multi-point sandwich forming

多点“三明治”成形是一种针对小批量多曲率板材工件制造而提出的新成形方法。用该方法成形时,上模采用聚氨酯模具,下模为型面可调节的多点模具。为了使多点模具型面连续化和消除工件表面的压痕,在成形过程中使用了金属护板和弹性垫板。由于工件板材两侧都和聚氨酯相接触,因此成形后工件的表面质量好。为了研究采用多点“三明治”成形复杂三维曲面工件的成形过程以及成形可能会出现的表面缺陷,文章选用马鞍面作为目标形面进行了实验研究,提出了用于提高工件的贴模程度,通过改变上模形状的分步成形方法,并得到了Q235B板材厚度和可成形马鞍形工件深度之间的关系曲线。

In this paper, multi-point sandwich forming （MPSF） process, a new sheet metal forming process, is put forward for manufacture of workpieces with different radius of curvature in small batch quantities. Polyurethane and multi-point die is used as the upper and lower die, respectively in this process. The steel die sheet is used to provide a continuous die surface and an interpolator to depress the dimples on the workpiece. Both surfaces of workpiece contact with polyurethane during deformation,therefore the workpiece can be manufactured with well surface quality. In order to investigate the forming process of workpiece with complex shape and the defect maybe occur on the surface of formed workpiece, the saddle shape workpiece s chosen as the target shape in experiment. And multi-step method is introduced in order to improve the fitness of workpiece in the multi-point die. Finally, the relationship between the thickness of Q235B blank and the maximum depth of saddle workpiece is obtained.