Nut integrated with bracket and method of manufacturing the same

A method of manufacturing a nut integrated with a bracket, the method comprising:

• forming a reference aperture and a processing cross section in a plate material supplied between a punch and a die during a pre-drawing operation;
• forming a beading portion in the processing cross section, and piercing a center of the beading portion during the pre-drawing operation;
• forming a pipe portion having a tube shape by gradually widening an aperture formed by piercing the center of the beading portion and decreasing a diameter of the pipe portion from the processing cross section to a tip of the beading portion during a forging operation;
• adjusting dimensions of the diameter of the pipe portion formed in the tube shape during a precision forging operation;
• forming a protruding end that extends on a tip surface of the pipe portion, subsequent to the forging operation;
• cutting the processing cross section to a final product shape, forming bent ends, which are supported on the protruding end, at both end portions of the cut processing cross section during a post processing operation;
• and
• forming a threaded tap on an inner circumferential surface of the pipe portion, subsequent to the precision forging operation,
• wherein the precision forging operation includes:
• adjusting the dimensions of the pipe portion during an upsetting operation by compressing the pipe portion, formed in the tube shape, in a longitudinal direction subsequent to the forging step;
• and
• removing residual burrs on a surface of the pipe portion during a cam rest burring operation by compressing interior and exterior circumferential surfaces and a tip portion of the pipe portion with the protruding end subsequent to the cam upsetting operation, wherein the cam rest burring operation is performed by left and right cam dies, and an upper punch configured to move in an upward direction and a downward direction,
• wherein the post-processing operation includes:
• cutting the processing cross section along an effective shape during a blanking operation, subsequent to the cam rest burring operation;
• forming the bracket during a flanging operation in which the bent ends are formed by bending the end portions of the processing cross section, and tips of the bent ends are supported on the protruding end, subsequent to the blanking operation;
• and
• forming the nut by processing the threaded tap on an interior circumferential surface of the pipe portion during a tapping operation, subsequent to the flanging operation, and
• wherein in the flanging operation, the end portions of the bracket are bent to surround both sides of the pipe portion, respectively.