Title:
METHOD FOR DESIGNING DIE FOR PRESS FORMING, AND DIE FOR PRESS FORMING
Document Type and Number:
WIPO Patent Application WO/2013/094177
Kind Code:
A1
Abstract:
The strain on a metal sheet surface when a predominantly ductile crack occurs is calculated from the minimum radius of curvature R0 of a die for press forming and the limit strain εf of the plane strain region in a forming limit diagram. By this means, a prediction expression "R0/t ≧ (2R/t+(2R/t+1)εf) / 2(1-(1+2R/t)εf)" is derived by which it can be determined that predominantly bending cracks will not form if the calculated strain is less than or equal to the limit surface strain εcritical. Also, in order to prevent the occurrence of predominantly bending cracks, the minimum radius of curvature R0 required in the die is predicted, and a die can be designed having a radius of curvature greater than or equal to the minimum radius of curvature R0.
Inventors:
FUJII YUSUKE (JP)
SHINMIYA TOYOHISA (JP)
YAMASAKI YUJI (JP)
HIGAI KAZUHIKO (JP)
SHINMIYA TOYOHISA (JP)
YAMASAKI YUJI (JP)
HIGAI KAZUHIKO (JP)
Application Number:
PCT/JP2012/008062
Publication Date:
June 27, 2013
Filing Date:
December 18, 2012
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
B21D22/00
Foreign References:
| JP2009255126A | 2009-11-05 | |||
| JP2001079617A | 2001-03-27 | |||
| JP2007152407A | 2007-06-21 | |||
| JP2010069533A | 2010-04-02 | |||
| JP2007152407A | 2007-06-21 |
Other References:
LIWEI GU ET AL.: "Tetsu-to-Hagane", vol. 88, 2002, THE IRON AND STEEL INSTITUTE OF JAPAN, article "Prediction of Forming Limit Diagram (FLD) and Effect of Work Hardening Property on FLD of Sheet Metals", pages: 88 - 94
See also references of EP 2796220A4
See also references of EP 2796220A4
Attorney, Agent or Firm:
KUMASAKA, Akira et al. (JP)
Akira Kumasaka (JP)
Akira Kumasaka (JP)
Download PDF:
Claims: