INTERNAL SIDE WELDING EQUIPMENT OF TUBULAR BODY JOINING PART

PROBLEM TO BE SOLVED: To remarkably improve the workability of welding the internal surface of a joining part, and to improve the working environment by mounting an expansion beam entering a tubular body on a traveling truck, and mounting a welding machine on a tip part of the expansion beam. SOLUTION: In an internal surface welding equipment 1, two tubular bodies 2, 3 are respectively loaded on turning rolls 4, 4 and arranged in a series, tubular end parts 2a, 3a which are opposite to each other with the prescribed root gap are butted to each other, and the internal surface at a groove joining part is performed. A traveling truck 5 is installed, and an expansion beam 6 entering the tubular bodies 2, 3 are mounted thereon. A welding machine 7 is mounted on a tip part of the expansion beam 6. The expansion beam 6 is formed so that a parent beam 6a and a child beam 6b are advanced/retracted by e.g. the hydraulic drive. A welding truck 8 moving in the tubes 2, 3 is fitted to the tip part of the expansion beam 6, and the welding machine 7 is mounted thereon. The working environment can be remarkably improved thereby.