Title:
【発明の名称】絞りプレス型
Document Type and Number:
Japanese Patent JP2560416
Kind Code:
B2
Abstract:
PURPOSE:To prevent wrinkle formation by arranging plural draw beads laid at each corner part of a blank holder plane nearly in parallel with the straight lines combining the central point of a curved line part at the corner part with the center of curvature of the curved line part or so that the straight lines are held. CONSTITUTION:Draw beads 8 are formed on a blank holder plane 3 of a lower die and a blank holder plane 5 of an upper die, the beads on the press surface 5 of the upper die protrude, the beads on the press surface 3 of the lower die take the shape of a groove and they face each other. The interval between these beads when they come most near and face each other is equal to the plate thickness. At each corner part 13 of the blank holder planes 3, 5, two draw beads 8 are arranged at an equal interval in parallel with and at both sides of the straight line combining the central point X of the curved line part 11 of a drawing profile 9 with the center O of curvature. The draw bead 8 is set from the straight line part 10 at a specified angle. Each point of the raw material W of the corner part 13 flows into a recessed part 2 nearly in parallel with the draw beads of arrow marks C. A member of a straight side part 12 performs a shrinkage flange forming converging into a certain point. In this way, wrinkles, cracks at corner parts are prevented from being formed.
Inventors:
HIRAMATSU TATSUO
Application Number:
JP12913588A
Publication Date:
December 04, 1996
Filing Date:
May 26, 1988
Export Citation:
Assignee:
TOYOTA MOTOR CO LTD
International Classes:
B21D22/26; B21D24/00; (IPC1-7): B21D22/26; B21D24/00
Domestic Patent References:
| JP60148628A |
Attorney, Agent or Firm:
Watanabe