HIGH FREQUENCY DIELESS BENDING METHOD FOR PIPE

摘要

PURPOSE:To increase the accuracy and efficiency in working by setting a high frequency heating coil at the position slightly before the axial line direction of a pipe than the bearing point of the base end of a movable arm. CONSTITUTION:The position A of the high frequency heating coil 8 which is outer-inserted into a pipe 1 is set at the position of the front part by the distance (d) on the axial line X-X more than the center O1 of the base end supporting pin 5a of a movable arm 5 in case of the high frequency direct bending of a pipe 1. The vicinity of the end part of the pipe 1 is heated by the high frequency heating coil 8 and the just before heating part is cooled by the water spray from a pipe cooling device 9 as well. The pipe 1 is advanced in the arrow mark direction in order by actuating a pipe feeding device 3 when the heating part of the pipe 1 reaches to the bending temp. The pipe end wrapped by the pipe end clamp 4 which is attached pivotally at the tip of the movable arm 5 receives the bending moment and is bent from the bending start point A of the part of which strength is reduced by heating.