CLAMP HEAD OF INTERNAL CLAMPING DEVICE AND INTERNAL CLAMPING DEVICE EQUIPPED WITH THIS CLAMP HEAD

摘要

PROBLEM TO BE SOLVED: To obtain a clamp head of an internal clamping device which surely forms a beautiful reverse side bead in which the height of the clamp head side coincides with the height of a backing material side.;SOLUTION: The clamp head 1 of the internal clamping device is arranged inside a pipe of piping to be welded, clamping the piping from the inner face by expanding the clamp head 1 externally in the radial direction of the pipe. The clamp head 1 includes a head body 5 formed with a holding groove 11 for holding the backing material 3, the backing material 3 which is held in the holding groove 11 of the head body 5 and is formed with a reverse side bead forming groove 23, and an energizing means 7 which can energize, externally in the radial direction of the pipe, the backing material 3 held in the holding groove 11. With the backing material 3 held in the holding groove 11, the upper end face of the groove wall 25 of the reverse side bead forming groove 23 projects from the upper end face of the groove wall 17 of the holding groove 11. By pressurizing the backing material 3 against the energizing force of the energizing means 7, the upper end face of the groove wall 25 of the reverse side bead forming groove 23 is caused to sink below the upper end face of the groove wall 17 of the holding groove 11.;COPYRIGHT: (C)2009,JPO&INPIT