ねじりが棒線材のせん断加工のだれ高さに与える影響

— 棒線材のねじり付加せん断加工　第1報 —

抄録

Shearing is a commonly used method of cutting materials for former from bars or wires. However, the cut face shape of a material after shearing is worse than that obtained with machine, saw, or laser cutting because droop and burr are formed at the edge of the cut face. It is necessary to alter the cut face shape after shearing for use in former. The cut face of a ductile material fractured by torsion is perpendicular to the longitudinal direction of bars or wires without droop or burr. In this research, we developed a new shearing method in which shearing is combined with twisting to achieve a short cutting time with a length high accuracy and a cut surface without droop or burr. A prototype machine for shearing a material with torsion was developed. Low-carbon steel bars (diameter: 1.96 mm) were used for the experiment. The specimens were annealed at 1123 K for 2 h. The specimens were sheared after being twisted at several torsion angles. As a result, the height of droop and burr decreased in the case of shearing with torsion, as compared with that in the case of only shearing.