| 摘要 |
PURPOSE:To manufacture a cross tube easily by converting a tube material from vertical direction to horizontal direction successively and performing bulge working. CONSTITUTION:Preliminary holes 11 are pierced upper and lower, right and left in a tube material 5 and the tube material 5 is placed on a holding face 6 of a lower die 23. Positions of lower hole 11 and a through hole for bulging 8 of the die 23 are squared, and a screwed part 9a at the tip of a pull-out rod 9 passed through the through hole 8 from below the die 23 is connected to a screw hole at the top of a piece 10 for forming a short tube. Two dies 22, 23 are fixed by covering another die 22, and a short tube part 12 is projected on a side of the tube material 5 by pressing both ends of an operating plate 25 and pulling out the piece 10. Then, it is inverted upside down with the tube material 5 and a short tube part 12 is formed by similar procedure on the die that becomes lower side. After forming vertical short tube parts 12, 12 as mentioned above, the upper die 23 is removed, and the tube material 5 is turned 90 deg. and formed short tube parts 12, 12 are positioned at an escape groove of the lower die 22 that constitutes an escape hole 24. Then, it is covered with the upper 22, and vertical short tube parts 12, 12 are formed by similar procedure. |
