The study on forming principle in the process of hydro-mechanical reverse deep drawing with axial pushing force for cylindrical cups

A novel device of hydro-mechanical reverse deep drawing with axial pushing effect for cylindrical cups is proposed. The axial pushing force is exerted on the brim of the blank by a special part of pushing ring. The fluid pressure supplied for die cavity and axial pushing force can be controlled separately. Considering the annealing treatment between first stage and second stage, the finite element simulation of the hydro-mechanical reverse deep drawing process are conducted by DYNAFORM-PC code together with modifying the keywords of *LOAD_MASK manually. The effects of different technology parameters on the forming of deep drawing process are investigated by the method of finite element simulation in conjunction with experiment verification and the optimal technology parameters are obtained. It was proven that the axial pushing force can improve the deformation extent of blanks considerably, and is one of the key factors for reverse deep drawing. Experiments with thickness 1 mm and material 08Al (a China drawing steel) were performed using the developed device of hydro-mechanical reverse deep drawing with axial pushing force on the universal hydraulic press, XP-S-500. The experimental results are in good agreement with the numerical simulation results.