MANUFACTURING DEVICE OF ROUND STEEL PIPE AND ROUND STEEL PIPE MANUFACTURING FACILITY

摘要

To provide a manufacturing device which can manufacture a round steel pipe from a steel plate by a simplified facility constitution and a simple manufacturing process, and a round steel pipe manufacturing facility.SOLUTION: In a method for manufacturing a round steel pipe 99 from a steel plate 90, a one-side first face 90a out of faces which are formed by partitioning a face for forming an inner wall of the round steel pipe 99 at the steel plate 90 into three zones is bent by press-molding, the other side second face 90b out of faces which are formed by partitioning the face for forming the inner wall of the round steel pipe 99 at the steel plate 90 into three zones is bent by press-molding, a third face 90c out of faces which are formed by partitioning the face for forming the inner wall of the round steel pipe 99 at the steel plate 90 into three zones is bent by press-molding, a semi-molded round steel pipe 96 is manufactured by welding a side edge of the steel plate 90 at the first face 90a side, and a side edge of the steel plate 90 at the second face 90b side while being abutted on each other, and the semi-molded round steel pipe 96 is molded to the round steel pipe 99 by pressurizing an inner wall of the manufactured semi-molded round steel pipe 96. There is also provided a round steel pipe manufacturing facility 10 for the method.SELECTED DRAWING: Figure 1