Flux concentrating ring

The invention discloses a flux concentrating ring, which comprises a U-shaped flux concentrating tube, a coil and a flux concentrating plate. The coil is arranged in a U-shaped cavity of the U-shaped flux concentrating tube, the upper end face of the U-shaped flux concentrating tube is provided with bosses, a turnup ring is arranged in the middle of the flux concentrating plate, holes matched with the bosses are arranged on the periphery of the turnup ring on the flux concentrating plate, the flux concentrating plate covers the upper end face of the U-shaped flux concentrating tube, the turnup ring in the middle of the flux concentrating plate extends into an inner hole of the coil, and the bosses of the upper end face of the U-shaped flux concentrating tube extend into the hole on the flux concentrating plate and form boss turnups. The bosses of the upper end face of the U-shaped flux concentrating tube can extend into the holes on the flux concentrating plate and form the turnups by a pneumatic press and a tooling press head only without utilizing a laser welding machine, and equipment cost is greatly reduced, operation is simple and the defect of requirement for welding in existing structure is overcome.