| 摘要 |
The present invention is carried out to supply a small sized and lightweight steel pipe bending apparatus so as to bring to construction sites, so as to keep thinning a thickness of the pipe at lower level and so as to obtain the pipe with a desired bending radius. The following apparatus realizes above-mentioned objectives of the present invention. A pipe bending apparatus comprises a heater (10, 11, 12) to heat a steel pipe (1) circularly around a center axis of the pipe, a tensile force applying mechanism (2, 3, 4, 5) to apply the tensile force on points of application which are located in the opposite directions from the circular heated portion, a variable controlling regulator (16, 19, 20) to control the tensile force variably, a transfer unit (7, 28, 31) to transfer the heated portion and the steel pipe relatively to the heater in the direction of the axis of the steel pipe and a controlling unit (14, 20) to control a velocity of the transfer. |
