| 摘要 |
PURPOSE:To obtain a correct bending angle and bending radius by giving a pipe the initial bending moment in the same direction as the bending moment at bending time prior to the bending. CONSTITUTION:Both ends of a pipe 1 is held by a fixing device 2 and revolving arm 4 and the pipe 1 is heated by a heater 6, but in this case the temp. rises slightly lower than the temp. necessary for bending. An axis 3 is moved from the position O to O' with the action of the bending moment in the same direction as the bending moment at the bending time via the revolving arm 4 on the pipe 1 when the load in the right direction is acted on the revolving axis 3 by a driving mechanism 5 in parallel to the preheating of the pipe 1 or prior to the preheating. In this case the bend is not caused due to the pipe 1 being not heated upto the bending temp. The pipe 1 is raised to the bending temp. after making it in the state of causing a cold deflection and the load given to the axis 3 is made the load necessary for causing the generation of the bending moment necessary for the bending. When the heater 6 is moved to the right direction simultaneously, a continuous bending is performed on the pipe 1.
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