| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a metallic smooth tube in which the tube is not broken even when the working ratio is large, and the wall thickness can be easily changed and finely adjusted. SOLUTION: The smooth tube manufacturing method includes a material-reducing step in which a smoothing plug 23 is inserted in a metal tube 10, and the metal tube is pressed by a pressing means to reduce the wall thickness of the metal tube from the outside of the metal tube at the position where the smoothing plug is inserted while drawing the metal tube, and a contraction step in which the metal tube material-reduced in the material-reducing step is drawn by at least one drawing die 42, and the outside diameter of the metal tube is contracted to the predetermined outside diameter dimension. The pressing means has a rolling member 31 turnably installed around the axis at the distance of the required wall thickness from the smoothing plug in the radial direction from the axis with the smoothing plug 23 being inserted in the metal tube 10 with respect to the smoothing plug. The material-reducing step is constituted of the form rolling by the smoothing plug and the rolling member. COPYRIGHT: (C)2011,JPO&INPIT
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