An investigation of material flow analysis in fineblanking process

As is well known, fineblanking is an effective and economical metal cutting process which offers the ability to produce clean-cut parts with close tolerances by eliminating rough cracks in the shearing zone. These advantages over the conventional blanking are possible due to the following three special tool designs: a small clearance, a high pressure on the blank holder and a high pressure on the counterpunch. These special tool designs affect the material flow characteristics. Therefore, in this study, the material flow was investigated with respect to the various blank holder forces and counterpunch forces by the finite element method (FEM). Moreover, the simulation results agreed well with the experimental results. The results indicated that applying high blank holder force and high counterpunch force significantly suppresses the formation of rotating flow in the blanked material during fineblanking. On the basis of the results, we clarified the reason why the clean-cut surface increases with increasing blank holder force and counterpunch force. Furthermore, this study also verified that the FEM simulation results could be useful for predicting the cut surface features for fineblanking products.