锥形件拉深成形中的弯曲与反弯曲变形分析及拉深力的计算

针对帽形弯曲成形，建立了弯曲与反弯曲的几何模型，分析了板坯多角弯曲时的弯曲和反弯曲现象，给出了产生反弯曲变形的判定条件。在此基础上，进一步研究了锥形件拉深成形中的弯曲与反弯曲问题，指出了在拉深初期并不产生反弯曲变形。计算拉深力时，应首先判断是否产生了反弯曲变形，然后再考虑反弯曲变形对成形过程的影响。

Analysis of Bending and Reverse Bending Deformation and Calculation of Deep Drawing Force for Conical Workpiece

The deformations of bending and reverse banding occur widely in many stamping processes such as bending, deep drawing, expanding, flanging and other sheet forming processes.The geometrical model of bending and reverse bending is established and the phenomena of bending and reverse bending are analyzed for sheet bending with multi-angular deformations. The decision condition is given as the reverse bending deformation occurs. Furthermore, the bending and reverse bending deformations are analyzed for conical workpiece in deep drawing by this method. It is pointed out that the reverse bending deformation does not occur in initial stages of deep drawing. Before calculating the deep drawing force, it should be estimated whether the reverse bending exists or not. Only after that the effect of reverse bending on the forming process is taken into account.