Electromagnetic forming method

Pipe outer peripheral members are disposed at a plurality of locations of the pipe material. A coil unit having a conductor winding portion is disposed on one axial end side of a pipe, and a support member is disposed on the other axial end side of the pipe. The coil unit and the support member are moved relative to each other in the axial direction to coaxially hold the coil unit at the tip of the support member, and the conductor winding portion of the coil unit is disposed inside the pipe material at a position overlapping the pipe outer peripheral member. The pipe material is expanded by an electromagnetic force generated by energizing the coil unit, and the pipe outer peripheral member is fixedly connected to the pipe material. 在管材的多个部位配置管外周部件。将具有导体卷绕部的线圈单元配置在管材的轴向一端侧，将支承部件配置在管材的轴向另一端侧。使线圈单元和支承部件在轴向上相对移动而使支承部件的前端部同轴地保持线圈单元，并且将线圈单元的导体卷绕部配置在管材的内部且与管外周部件重叠的位置。借助向线圈单元通电而产生的电磁力，使管材扩管，使管外周部件固接于管材。