两种压边方式下板料拉深成形性能及载荷分析

Formability and Forming Load Analysis of Sheet Drawing under BHF and BHG

对具有双曲底面的盒形件在设定压边力(BHF)和设定压边间隙(BHG)两种压边方式下的拉深成形进行了数值模拟和试验研究,分析了BHF压边方式下压边力的变化以及BHG压边方式下压边间隙的变化对板料成形性能及设备成形载荷的影响.结果表明:BHF压边方式下,在一定范围内变动的压边力对成形性能及载荷影响不大;而在BHG压边方式下,压边间隙的变化对成形性能及压边载荷的影响显著,稍大或稍小的压边间隙都会使盒形件拉深深度明显降低,压边载荷显著增大.研究结果可为不同设备、不同成形方式下的拉深工艺和模具设计及试生产提供有益的指导.

Blank holding force （BHF） and blank holding gap （BHG） are two modes usually used in complex sheet forming process to control formability. The forming process of a hyperbolic bottomed box under BHF and BHG modes was simulated and then validated by experiments. The influence of variable BHF and variable BHG on the formability and forming load were analyzed. The results show that, in BHF mode, the influence of variable blank holder forces on the formability and forming load is very small, while in BHG mode, blank holding gap affects the formability and forming load significantly. Too large or too small blank holding gap will cause the formability deterioration and increase the blank holding force largely. The research can guide drawing process and drawing die design and troubleshooting under different equipments and forming modes.