PURPOSE: To improve bending accuracy by pulling, after bending one end of a pipe, the other end of the pipe with one end held and thereby reducing the quantity of spring back at the bent part of the pipe.
CONSTITUTION: After the lower right end part of the pipe 11 is clamped by a clamp part 15, a tightening die 16 is moved downward by a cylinder 18 and the upper right end part of the pipe 11 is clamped. Then, a roll 14 is rotated clockwise through a rotary shaft 13, and the right end of the pipe 11 is bent. After the bending, with the right end of the pipe 11 held by the clamp 15 and the tightening die 16, a slide mechanism 27 is moved to the left by a cylinder 29 to pull the left end of the pipe 11. Thus, a tensile stress is applied on the outer side of the bent part 11a of the pipe 11 ; and as the tensile stress becomes larger, the spring back quantity at the bent part 11a of the pipe 11 is gradually reduced.
| JPS5439361 | PIPE BENDER |
| JP2724545 | BENDING MACHINE FOR PIPE |
HORINO KATSUYOSHI
YOKOI MICHIHARU
| JPS5540005A | 1980-03-21 |