| 摘要 |
PURPOSE:To manufacture a tough angle bar having an acute outer angle and a round inner agnle, by pressing a plate by using an upper die having a projecting round edge and a lower die havng bent recessed part, and forming the angle bar by cutting off the projecting round edge formed on the outside of it. CONSTITUTION:The edge of an upper die 4 is formed into a round, projecting shape bar having roundness 6 smaller than the thickness of a plate 1 in size, and the corner of bent part of a lower die 9 is formed into a recessed round groove 8 along the die 4, and the plate 1 is pressed by the upper and lower dies 4 and 9. The plate 1 is smoothly pressed into the groove 8, and is bent into an angle bar-shape without causing any troubles and producing cleavages, etc.. The formed plate 1 is taken out, and by cutting off 13 a part 11 projecting from the plate surface; an angle bar, of which an inner angle has a recessed roundness 2 and an outer angle has an acute angle 3 and a formed edge-thickness 5 is equal to the thickness of plate 1 is obtained. |
