PIPE MANUFACTURING METHOD

To suppress occurrence of wrinkles and cracks near a border between a pipe body and a taper part.SOLUTION: A pipe manufacturing method comprises: a process in which a plate-like member is press-molded into a U shape; and a process in which the plate-like member, which has been molded into the U shape, is press-molded into an O shape. A pipe to be manufactured has a pipe body, and a taper part which inclines inward in a radial direction from one end of the pipe body and projects. Before the process for press-molding into the U shape, a boundary between a portion of the plate-like member corresponding to the pipe body and a portion thereof corresponding to the taper part is pressed from a side of a surface corresponding to an inner peripheral surface of the pipe to bend the taper part inward in the radial direction.SELECTED DRAWING: Figure 4 【課題】パイプ本体とテーパ部との境界付近における皺や割れの発生の抑制。【解決手段】板状部材をＵ字状にプレス成形する工程と、Ｕ字状に成形された板状部材をＯ字状にプレス成形する工程と、を備えたパイプの製造方法である。製造されるパイプは、パイプ本体と、当該パイプ本体の一端から半径方向内側に傾いて突出したテーパ部と、を有しており、Ｕ字状にプレス成形する工程の前に、板状部材におけるパイプ本体に対応する部位とテーパ部に対応する部位との境界部を、パイプの内周面に対応する面側から押圧し、テーパ部を半径方向内側に折り曲げておく。【選択図】図４