To provide a method of forming the flange part of a hub hole of an automotive wheel, in which the occurrence of cracks or the like is suppressed when forming the flange part of the hub hole.
By pressing the peripheral part 23 of a prepared hole 22 with a preworking punch 44 and a supporting die 43 after boring the prepared hole 22 for setting to a planar base material 21, surplus materials pressed with the preworking punch 44 is set into a setting space 46 which is provided on the prepared hole and at least one of the preworking punch 44 and the supporting die 43, next, the rough round hole 28 is formed with a punching punch 50 and, after that, the flange part 6 of the hub hole is formed by performing hole expanding work for erecting the peripheral part 29 of the rough round hole 28 toward the front side of the wheel. Because work hardening generated in the peripheral part 29 of the rough round hole 28 is suppressed by this method, the occurrence of the cracks is suppressed when performing the hole expansion for forming the flange part 6 of the hub hole.
KATO KOZO
YOGO TOKIYASU
| JP2001269723A | 2001-10-02 |
Yasutoshi Iwata
Yu Yamamoto