TUBE EXPANSION FIXTURE, TUBE EXPANSION METHOD, CYLINDRICAL BODY AND COMPACTOR

摘要

PROBLEM TO BE SOLVED: To provide a tube expansion fixture or the like capable of manufacturing a cylindrical body having excellent inner diameter roundness by lowering the height of a salient generated by a clearance between split molds in tube expansion processing.SOLUTION: In a tube expansion fixture having a tube expansion mold 71 constituted in a cylindrical shape, for expanding a winding steel tube 8 from the inside by moving to the outside in the radial direction, a plurality of split molds 71a constituted by splitting the tube expansion mold 71 in the circumferential direction, each shape of facing surfaces of each split mold 71a adjacent mutually in the plurality of split molds 71a has a zigzag shape.