Title:
PRECISE 2-DIMENSIONAL PLASTIC WORKING DIE FOR RECTANGULAR CROSS-SECTION MATERIAL
Document Type and Number:
Japanese Patent JP3519452
Kind Code:
B2
Abstract:
PURPOSE: To surely keep the accurate bending dimension by compressing an increased mass of the thickness of a material to be worked generating in a bending time with a low pressure.
CONSTITUTION: After a metal blank to be worked is inserted between grooves formed at outer circumferential ends of upper and lower dies 1, 2 for forming, the bending of a 1st step is executed by acting a 1st step lateral pressing die 3 with a lateral pressing die hydraulic jack 6 and pressurizing from the outer circumference of the forming dies 1, 2. In order to flatten an increased mass of the material to be worked of a rectangular cross section, a flatness correcting die 7 is lowered by operating a flatness correcting hollow jack 8, made in contact with the upper surface part of the forming upper die 1, the upper die 1 is pressed toward the lower side and the increased mass of the metal blank to be formed set between the grooves 15 is made flat. After finishing the operation, the lateral pressing die 6 and the flatness correcting hollow jack 8 are returned to the original position. Next, the same like pressing and bending are again executed with a 2nd step lateral pressing die 4. Finally, the blank is bent into the deeper bending angle (large radius of curvature) R with a 3rd step lateral pressing die 5.
Inventors:
Yamazaki, Masato
Ota, Takashi
Ota, Takashi
Application Number:
JP13673794A
Publication Date:
April 12, 2004
Filing Date:
May 27, 1994
Export Citation:
Assignee:
MITSUBISHI HEAVY IND LTD
International Classes:
B21D11/20; B21D5/01; B21D37/01; (IPC1-7): B21D11/20
Attorney, Agent or Firm:
鈴江 武彦 （外５名）