PURPOSE: To prevent dislocation of upper flange of formed product by forming a formed product having shape analogous to a square steel pipe to take regular shape of square steel pipe by pressing it from inside and outside.
CONSTITUTION: Both side ends of a steel plate B pulled out from a material coil A by a pinch roll leveller 1 and straightened are cut by a trimmer 2, and both side ends are straightened to specified shape by an end face straightener 3. Then, it is cut to specified length by a cutter 4, and formed to take shape analogous to a square steel pipe. The formed products C of upper side and lower side formed by a press 5 are connected while moving by a travelling welding machine 6 and sent to a forming roll 7. There, it is formed to take regular shape, and at the same time, butted end parts of left and right flanges are welded by a welding machine 9, and excessive bead is removed by a bead removing device 10. Then, it is cooled by a cooling device 11, straightened by a straightening roll 12, and inspected by a supersonic flaw detector 13. Tack welded part is cut by a travelling separator 14, and a square steel pipe D is obtained.
SASAKI HARUO
IKENAGA TAKAYASU
TAKENAKA YUKITOSHI
| JPS48739A | ||||
| JPS55112128A | 1980-08-29 | |||
| JPS5481157A | 1979-06-28 |
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