Anti-deformation top bending die for ultra-large circular tube

The utility model belongs to the technical field of ultra-large circular pipe machining, and particularly relates to an anti-deformation top bending die for an ultra-large circular pipe. The device comprises a stable bottom plate, a plurality of first fixing plates are vertically arranged on the side edge of the stable bottom plate, a plurality of second fixing plates are arranged on one side of each first fixing plate, the second fixing plates are connected with the side wall of the stable bottom plate, and rotary connecting plates are arranged between the first fixing plates and the second fixing plates. Through the arrangement of the structure that the circular tube upper fixing plate and the circular tube lower fixing plate are matched with each other, the torsion spring can provide elastic abutting force for the circular tube upper fixing plate, so that the circular tube upper fixing plate can be firmly matched with the circular tube lower fixing plate, and the area with the cross section larger than the