| 摘要 |
PURPOSE:To better contact of a core pipe and a formed body and to ensure soldering by making the inner end imaginary diameter at the time of forming of a formed body smaller than the outer diameter of the core pipe when winding the formed body from a tapelike material by a forming device around the core pipe. CONSTITUTION:A tapelike material 1 is wound around a pin 26 of a die rotating body 12 and its tip is clamped to a core pipe P. Pressing dies 20a, 20b are lowered successively to bend the tapelike material 1. The axis O1 of the core pipe P is slightly displaced from the axis O of a hollow shaft unified with the die rotating body 12 in the direction of thrusting of the pressing dies 20a, 20b. The amount of extrusion is so made that it comes nearly into contact with the displaced core pipe P. Consequently, the inner end of the formed body is on the inner end imaginary diameter (d) that makes a line O-P' connecting the hollow axis O and formed inner end P' a semicircle. This inner end imaginary diameter (d) is smaller than the outer diameter D of the core pipe P, and when the formed body is wound around the core pipe P, it is expanded by (D-d)/2, and contact with the core pipe P is improved. |
