Title:
スチールホイールにおけるボルト穴の成形方法
Document Type and Number:
Japanese Patent JP4435376
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To produce the cost of a machine and equipment, to improve the working efficiency, and to reduce the product cost by forming a prepared hole and tapered surfaces on the obverse and reverse by sides series of pressing operations. SOLUTION: This forming method comprises a first step of blanking the prepared hole 9 in a stock material 1a by a punch and a die, and a second step of arranging an upper die coining punch 10 having a tapered portion 10b with a contracted tip on a face side of the punched prepared hole, arranging a lower die coining punch 11 having a tapered portion 11b with a contracted tip on a back side of the prepared hole 9, and forming the tapered surfaces on the face and back sides of the prepared hole 9 by the coining punches 10 and 11. The diameter of the prepared hole 9 blanked in the first step is set to be larger for the small fluctuation of the hole diameter in the second step.
Inventors:
Noriyuki Fukaya
Application Number:
JP2000147225A
Publication Date:
March 17, 2010
Filing Date:
May 19, 2000
Export Citation:
Assignee:
Chuo Seiki Co., Ltd.
International Classes:
B21D22/02; B21D53/26; B21D19/00; B21D28/24; B21D53/86
Domestic Patent References:
| JP10513414A | ||||
| JP60151630U | ||||
| JP10296691A |
Attorney, Agent or Firm:
Hasegawa Yoshimichi