| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for shaping groove parts of a pipe material, allowing deeper formation of the groove parts than before, even if using the thin pipe material. <P>SOLUTION: The depths of a recessed part 72 and wide recessed parts 71 are set such that the inner circumferential face of the crushed pipe material 60 for a headrest stay does not come in contact with the bottom faces 71c, 72c of the recessed part 72 and the wide recessed parts 71 when having crushed the outer circumferential face of the pipe material 60 for the headrest stay into the recessed part 72 and the wide recessed parts 71, the left and right side faces 52a, 52b of a rectangular blade 52 are positioned on the left and right inner sides of the left and right inner walls 72a, 72b of the recessed part 72, the right side face 51b of each inclination blade 51 is positioned on the left inner side of the right inner wall 71b of each wide recessed part 71, thereafter the pipe material 60 is pressed with the rectangular blade 52 and the inclination blade 51 such that the lower end of the rectangular blade 52 enters the recessed part 72 and such that the lower ends of the inclination blades 51 enter the wide recessed parts 71, and the groove parts 61, 62 having groove depths larger than the wall thickness of the pipe material 60 are formed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
