| 摘要 |
A bending type butterfly nut manufacturing method which can mass-produce integrally formed butterfly nuts and can improve clamping force of the butterfly nut even without a washer, and a bending type butterfly nut manufactured by the same are provided. A bending type butterfly nut manufacturing method comprises: a steel plate feeding step(10) of feeding a steel plate having a pilot piercing formed at both sides thereof to a mold; a first drawing step(20) of forming an embossing on the center of the steel plate; a piercing step(30) of perforating the center of the embossing of the steel plate; a burring step(40) of forming a screw hole on the perforated hole of the steel plate; a bead forming step(50) of forming beads at an outer side of the screw hole of the steel plate; a slot cutting step(60) of forming a cutout groove at an inner side of the beads; a spring bending step(70) of bending cutout elements formed in the cutout grooves; a notching press step(80) of forming fixing holes between the beads of the steel plate; an outer wall notching step(90) of notching outer sides of the beads of the steel plate by a press; a first bending step(100) of primarily bending handle parts at right angles; a second bending step(110) of bending the handle parts toward the fixing holes at right angles to fix the handle parts into the fixing holes; a tap forming step(120) of forming a spiral on an inner diameter of the screw hole; and a plating step(130) of plating an external form of a butterfly nut.
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