剪断加工工具の寿命試験(その二)

抄録

In this research the 12 × 7.2 mm and 8 × 5 mm rectangular blanking tools are used. With the former which is made from high carbon high chromium tool steel No.1, 400, 000 brass blanks of 0.6 mm thickness are cut out and with the latter made from special tool steel No.2, 40, 000 blanks of high class finished mild steel of which thickness is 0.5mm are cut out. The results obtained are as follows:
1. In the sectional shape of blanks, burrs, depth of distortion of blank surface, width of sheared surface and angle of fractured surface increase gradually in proportion to wear of cutting edge, while angle of sheared surface decreases. These phenomena can be seen in both brass and steel blanks.
2. In proportion to wear of cutting edges, the roughness on the side of die and punch edge, the upper surface of die edge and sheared surface of blanks increase gradually in both brass and steel blanks.
3. The outermost dimension of blanks, in proportion to wear of cutting edges, becoms gradually larger than the original one in both brass and steel blanks.
4. And others