Burr-free cutting edges by notch-shear cutting

Abstract

Shear cutting is used to separate a sheet metal into two parts. During the cutting process, the material is deformed by two moving parts until its formability is exhausted. When a material is sheared, a burr deformation can often be observed on the cutting edge. Due to different disturbing effects, the burr must often be deburred before the next process of machining. The objective of the paper is the production of sheets without a burr under industrial boundary conditions. Therefore a progressive die is built in order to perform the necessary experiments. In addition to the experiments the simulation tool Abaqus is used to reduce the number of experiments to a suitable minimum. Adjusting a notching with a cutting process a burr-free cutting edge should occur. The notching results in a local change of formability on the blank sheet. Subsequently, the sheet metal is cutted in a normal shear process at the same position of the sheet metal where the notch at first was pressed into the bottom of the sheet. Due to the lowered deformability at this part of the sheet, the cutting edges of the sheet metal cannot build up any burr. Therefore, the impact of different parameters on the cutting edge is analyzed to create a notch geometry as well as shear cutting parameters without burr deformation, furthermore continuous strokes are performed to show the impact of this new cutting process for industrial applications on the tool material. Additionally to the burr free cutting edge, the new method shows less wear than the normal shear cutting.