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:
Apr. 24, 2018
Filed:
Oct. 10, 2013
Jfe Steel Corporation, Tokyo, JP;
Osamu Sonobe, Tokyo, JP;
Akinobu Ishiwatari, Tokyo, JP;
Masaki Urabe, Tokyo, JP;
Hirotaka Kano, Tokyo, JP;
Jiro Hiramoto, Tokyo, JP;
JFE STEEL CORPORATION, Tokyo, JP;
Abstract
A method for manufacturing a press formed part, the method including specifying stretch flange limit strain in a metal sheet by using strain gradient in a radial direction and strain gradient in a sheet thickness direction. The strain gradient in the radial direction being directed from an end portion of the metal sheet at a time a press load is applied. The strain gradient in the sheet thickness direction being a direction of the metal sheet that intersects a loading direction. Additionally, the stretch flange limit strain satisfies the formula ϵ=A[a·Δϵ/Δr+b·Δϵ/Δt]+c, where ϵrepresents the stretch flange limit strain in a tangential direction of the sheet edge, Δϵ/Δr represents the strain gradient in the radial direction, Δϵ/Δt represents the strain gradient in the sheet thickness direction, A, a, and b represent influence coefficients, and c represents the limit strain at a time the strain gradient is zero.