| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a device that can apply a press working to a recess portion with high precision on a headrest stay consising of a metallic pipe material and can reduce press-working cost. SOLUTION: A plurality of roll punches 36A-36D, 37A-37D, 38 different in diameter are successively pressurized to one place on the surface of a headrest stay 10 to press-form recessed portions 14, 15, 16 in steps, thereby suppressing generation of shear drops and flashes and increasing accuracy in the dimension and shape of the recessed portions 14, 15, 16. By making a plurality of sets with the line of roll punches 36A-36D, 37A-37D, 38 and by shifting the axial centers 34a, 35a of the shafts 34, 35 on which these roll punches 36A-36D, 37A-37D, 38 are assembled, only one roll punch 36A-36D, 37A-37D, 38 is constantly designed to be pressurized to the headrest stay 10. COPYRIGHT: (C)2005,JPO&NCIPI
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