Manufacturing method and device for C-shaped inner opening thin-wall metal annular piece

The invention provides a manufacturing method and device for a C-shaped inner opening thin-wall metal annular piece. The manufacturing method for the C-shaped inner opening thin-wall metal annular piece comprises the steps that A, pipe coiling is conducted during blanking, specifically, a plate cut according to the size is coiled into a cylinder; B, welding is conducted, specifically, the circular plate is welded into a straight seam circular pipe through a laser welding machine; C, segmented cutting is conducted, specifically, the cylinder is segmented and cut into a planar annular piece according to the size of the unfolded section of the C-shaped inner opening annular piece; and D, the planar annular piece is rolled and formed through a symmetrical three-roller rolling machine, and the C-shaped inner opening thin-wall metal annular piece is obtained. The manufacturing device for the C-shaped inner opening thin-wall metal annular piece comprises the symmetrical three-roller rolling machine, and the symmetri