Research On The Hybrid Segmental Blank Holder Method Of Deep Drawing Technique For Rectangular Box Part

Wrinkling and fracture are the most common flaw in the process of deep drawing.Blank holder force(BHF) plays an important role for the smoothness of forming parts. In the sheet forming filed, it has been the research focus and technology nodus.The hybrid-segmental-blank holder method is proposed for the rectangle box parts,which means that the straight edge area and fillet area of flange are pressed along the circumferential direction respectively. What’s more, the fillet area adopt the radicalsegmental blank holder technique. Investigations are made focus on the influence law of the items including dividing method, dividing position, the ratio of holding force in each area. on the deep drawing process and the application of the technique.Firstly, analysis was carried out to clarify the influence of the dividing position, and the ratio of holding force on the deep drawing process for rectangle box parts using FEM. The flange is divided into 16 sections, which include 4 sections in the straight edge area and12 sections in the fillet sections. The geometrical parameters are determined according to the grand thickness rules. The best ratio of the straight edge and the fillet edge area is 0.9:1, the best holding force ratio of the inner, middle, outer section is 1:1.69: 0.46.Furtherly, the deep drawing in the process of the whole blank holder technology, the hybrid-segmental blank holder and circumferential-segmental blank holder are analyzed using FEM. It indicate that hybrid radical-segmental blank holder with variable force technology is better than the other methods, and the results of the integrate blank holder is the worst by comparing the highest forming height, thickness distribution, forming limit in the same process,. And finally, further researches on the hybrid-segmental blank holder varified the effect of inhabiting wrinkling and improving forming limit and the results proved the effectiveness of the new technique.Finally, the forming plant of rectangle box parts including the experiment mould and the varying holding force system. the holders in the module was designed to be double-deck,in which the top deck was divided in the flange area to press different section of the blank respectively while the bottom deck plays the role of supporting, in addition, the straight edge area and the fillet area was controlled with two independent hydraulic systemrespectively. the results demonstrates that the experiment system can well realize the hybrid-segmental blank holder technique and finish the deep drawing process.