| 摘要 |
PURPOSE:To enable the titled method to reform a bend efficiently without affecting a quality of a pipe, by a method wherein strong bend reformation is performed, to begin with, and the weak bend reformation is performed in order by making use of a caliber roll through a bend reformation machine which is of a three-roll type arranged in a multi-stage state within a specific temperature range. CONSTITUTION:Rolls 61-67 of a bend reformation machine are arranged within a heat insulation tank 5 which is of a hot air circulation type so that their amplitude becomes small in order in a zigzag state in a vertical direction and repeating bending order in a zigzag state in a vertical direction and repeating bending wherein the same is strong at the begining and becomes weak in order is applied to the pipe. The front and rear rolls 61, 67 are of driving rolls for fixation of positions and the intermediate rolls 62-66, which are of idle rolls, provided in a controllable state of a position vertically and bending radii of them can be controlled. A water-cooled cooling tank 8 cooling the reformed pipe is provided with guide rolls 9 at the front and rear of the tank 8. With this construction, the bend of a long-sized thermoplastic pipe 2 wound up into a coiled state can be reformed within a temperature range from the glass transition temperature +20 deg.C up to the fusion point -20 deg.C or the temperature where disassembly is begun. |
