The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 2013
Filed:
Jan. 22, 2007
Applicants:
Yoshikiyo Tamai, Tokyo, JP;
Yuji Yamasaki, Tokyo, JP;
Akihide Yoshitake, Tokyo, JP;
Inventors:
Assignee:
JFE Steel Corporation, , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B21D 22/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A press forming method for a metal sheet uses dies, a surface roughness of which is an arithmetical mean roughness Ra of 7.5 μm or smaller, which are used as a punch, an upper die, and a blank holder. Fluid with a kinematic viscosity of 500 mm/s or lower is supplied to a space between a metal sheet and the blank holder, a space between the metal sheet and the punch, and a space between the metal sheet and the upper die. A die is detached from a workpiece in the middle of forming, and resuming the forming.