公开(公告)号：US20250050403A1

公开(公告)日：2025-02-13

申请号：US18720757

申请日：2022-12-13

Applicant: JFE STEEL CORPORATION

Inventor： Masaki URABE ,  Akinobu ISHIWATARI

IPC: B21D22/02

Abstract: A method of evaluating a peripheral shape of a press formed part includes: acquiring, as a peripheral shape of an actual press formed part, a peripheral shape of a press formed part workpiece bottom dead center shape model acquired by mechanical analysis in a process of sandwiching the actual press formed part that is actually press-formed and is spring-backed up to a forming bottom dead center, obtaining a press formed part analysis model by elastoplastic mechanical analysis in a process of press forming the actual press formed part, acquiring a peripheral shape at the forming bottom dead center of the press formed part analysis model, and comparing the peripheral shapes of the actual press formed part and the press formed part analysis model and evaluating each of the peripheral shapes.

公开(公告)号：US20250025926A1

公开(公告)日：2025-01-23

申请号：US18715257

申请日：2022-12-13

Applicant: JFE STEEL CORPORATION

Inventor： Masaki URABE

IPC: B21D22/02

Abstract: A method of evaluating a springback amount of a press formed part according to the present invention, the method includes: obtaining a springback amount of an actual press formed part 11 (S3) by giving a predetermined constraint condition to a press formed part workpiece shape model 17 (S1) acquired by elastic mechanical analysis including a process of sandwiching the actual press formed part 11 obtained by performing actual press forming and springback up to the forming bottom dead center and performing spring-back analysis; calculating a springback amount (S7) by giving the same constraint condition to a press formed part analysis model 21 (S5) acquired by elasto-plastic mechanical analysis including a process of press forming the actual press formed part 11 and performing the spring-back analysis; and comparing and evaluating these springback amounts (S9).

公开(公告)号：US20230415215A1

公开(公告)日：2023-12-28

申请号：US18036298

申请日：2021-07-02

Applicant: JFE STEEL CORPORATION

Inventor： Yusuke FUJII ,  Masaki URABE

IPC: B21D22/26

CPC classification number: B21D22/26

Abstract: A press forming part includes: a top portion; a side wall portion continuous from the top portion via a punch shoulder; and a flange portion continuous from the side wall portion via a die shoulder, the press forming part having a curved portion curved in a recessed manner in a top view, wherein a bending radius of the die shoulder in the curved portion is increased from an end side toward a middle portion of the curve.

公开(公告)号：US20230398593A1

公开(公告)日：2023-12-14

申请号：US18033704

申请日：2021-06-30

Applicant: JFE STEEL CORPORATION

Inventor： Yusuke FUJII ,  Masaki URABE

IPC: B21D22/26

CPC classification number: B21D22/26

Abstract: A press forming method of press forming a press forming part that includes a top portion, a side wall portion continuous from the top portion via a punch shoulder, and a flange portion continuous from the side wall portion via a die shoulder, the press forming part having a curved portion curved in a recessed manner in a top view, the press forming method includes: making a bending radius of the die shoulder in the curved portion increased from an end side toward a middle portion of the curve.

公开(公告)号：US20230152195A1

公开(公告)日：2023-05-18

申请号：US17916698

申请日：2020-12-01

Applicant: JFE STEEL CORPORATION

Inventor： Fumiaki TAMASHIRO ,  Satoshi SUMIKAWA ,  Masaki URABE

IPC: G01N3/08 ,  B21C51/00

CPC classification number: G01N3/08 ,  B21C51/00

Abstract: A method for identifying a necking limit strain of a metal sheet includes a step of measuring the distribution of strain in a tensile orthogonal direction in a tensile deformation process of a notch root for two or more types of sheet specimens having a notch geometry in a portion of a sheet edge; a step of obtaining a strain increment ratio of the notch root in the tensile deformation process and a strain gradient in the tensile orthogonal direction; a step of obtaining necking limit strain at which necking occurs in the notch root based on the strain increment ratio in the tensile deformation process; and a step of identifying the necking limit strain as a function of the strain gradient from the relation between the necking limit strain obtained for the two or more types of sheet specimens and the strain gradient at that time.

公开(公告)号：US20230087377A1

公开(公告)日：2023-03-23

申请号：US17798771

申请日：2020-10-02

Applicant: JFE STEEL CORPORATION

Inventor： Yusuke FUJII ,  Masaki URABE ,  Shunsuke TOBITA

IPC: G06F30/23 ,  B21D22/24 ,  B21D22/26 ,  B21D22/30

Abstract: A shape change prediction method for a press formed part for predicting a shape change of the press formed part with a lapse of time units after springback at a moment of a release from a die includes: a shape/residual stress immediately after springback acquisition step of acquiring a shape and a residual stress of the press formed part immediately after the springback by a springback analysis of the press formed part; a residual stress relaxation/reduction setting step of setting a value of a residual stress relaxed and reduced from the acquired residual stress to the press formed part immediately after the springback; and a shape analysis step of determining a shape, in which moments of force are balanced, for the press formed part to which the value of the relaxed and reduced residual stress is set.

公开(公告)号：US20150294043A1

公开(公告)日：2015-10-15

申请号：US14436236

申请日：2013-10-10

Applicant: JFE STEEL CORPORATION

Inventor： Osamu SONOBE ,  Akinobu ISHIWATARI ,  Masaki URABE ,  Hirotaka KANO ,  Jiro HIRAMOTO

IPC: G06F17/50 ,  G06F17/10 ,  G01L5/00

CPC classification number: G06F17/5009 ,  B21D19/00 ,  B21D22/02 ,  B21D53/88 ,  G01L5/00 ,  G01M99/007 ,  G01N3/28 ,  G01N2203/0075 ,  G01N2203/0254 ,  G01N2203/027 ,  G06F17/10

Abstract: A method for specifying stretch flange limit strain includes specifying stretch flange limit strain so as to satisfy a relation in the following formula by using: strain gradient in an inward direction directed from an end portion of a metal sheet at a time a press load is applied; and strain gradient in a sheet thickness direction of the metal sheet intersecting the loading direction: εθlim=A[a·Δεθ/Δr+b·Δεθ/Δt]+c where εθlim represents the stretch flange limit strain (tangential direction of the sheet edge), Δεθ/Δr represents the strain gradient in the inward direction, Δεθ/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.

Abstract translation: 用于规定拉伸凸缘极限应变的方法包括：通过使用：在施加压力载荷时从金属板的端部指向的向内方向上的应变梯度来指定拉伸凸缘极限应变以满足下式的关系： ; 和与加载方向相交的金属板的板厚度方向的应变梯度：＆amp;＆amp;＆nbsp;＆nbsp;＆nbsp;＆nbsp;＆Dgr;＆rdquo;＆Dgr;＆ ] + c其中＆egr;＆thetas; lim表示拉伸法兰极限应变（片材边缘的切线方向），＆Dgr;＆Egr＆amp;＆Thetas; /＆Dgr; r表示向内方向的应变梯度，＆Dgr; ＆Dgr; t表示板厚方向的应变梯度，A，a和b表示影响系数，c表示应变梯度为零时的极限应变。