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.

Date of Patent:
Sep. 09, 2025

Filed:

Jun. 09, 2021
Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventor:

Yasuhiro Kishigami, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21D 53/88 (2006.01); B21D 22/26 (2006.01); B21D 24/04 (2006.01); B21D 37/10 (2006.01);
U.S. Cl.
CPC ...
B21D 53/88 (2013.01); B21D 22/26 (2013.01); B21D 24/04 (2013.01); B21D 37/10 (2013.01);
Abstract

A press forming method includes: moving a die toward a punch; bringing a punch side and a die side elastic bodies into contact with a metal sheet; and press forming the metal sheet, wherein an amount of protrusion of the punch side elastic body is set so that the punch side elastic body: comes into contact with the metal sheet before the punch; and becomes flush at a bottom dead center, and an amount of protrusion of the die side elastic body is set so that: the die side elastic body comes into contact with the metal sheet before the punch; and a product of: a load of the die side elastic body; and a friction coefficient between the die side elastic body and the metal sheet, becomes equal to or larger than an absolute value of a difference between tensions acting on the portions sandwiching a character-line equivalent portion.


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