MANUFACTURING DEVICE AND MANUFACTURING METHOD OF END PART DIAMETER REDUCTION PIPE

摘要

PROBLEM TO BE SOLVED: To properly and efficiently manufacture an end part diameter reduction pipe.SOLUTION: A manufacturing device comprises a columnar inner die 3 arranged in an end part of a spiral pipe 11 and an annular ring-shaped outer die 4 arranged on the outer periphery of the end part of the spiral pipe 11, and the inner die 3 comprises an inner die same diameter body 31 of the substantially same diameter as an inner diameter of the spiral pipe 11 and an inner die diameter reduction body 31 concentric with the inner die same diameter body 31, being a smaller diameter than the inner die same diameter body 31 and providing a concave formation groove 321 of extending in the axial direction on an outer peripheral surface. The outer die 4 is provided with a formation punch 411 freely advancing-retreating to an inner die diameter reduction body 31 and fitted to a formation groove 321 in a convex shape of extending in the axial direction on an inner peripheral surface, and the outer die 4 advances to the inner die diameter reduction body 31 side, and a diameter is reduced by sandwiching an end part of the spiral pipe 11 by the outer die 4 and the inner die diameter reduction body 31, and a groove-shaped recessed part 13 extending in the axial direction is formed.SELECTED DRAWING: Figure 10