| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for forming a spot facing in a thick sheet metal and a pressing apparatus that suppress an increase of motive energy required for pressing and enable a high dimensional accuracy. SOLUTION: A method for forming a piercing aperture 6 in the thick sheet metal 1 to form the spot facing on the surface of the end section side of the aperture and using No.1 punch having the same external diameter as the internal diameter of the piercing aperture, No.2 punch having a larger external diameter than the internal diameter of the spot facing to be formed, and No.3 punch 5 having approximately the same external diameter as the internal diameter of the spot facing to be formed, the piercing aperture is formed through No.1 punch on the thick sheet metal and the thick sheet metal is plastic deformed to a predetermined depth through No.2 punch, resulting in constituting a No.1 recessed section 7, and then, by plastic deforming the bottom surface of the No.1 recessed section to a predetermined depth through No.3 punch, No.2 recessed section 8 is formed, resulting in shaping the spot facing characteristically.
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