公开(公告)号：US20240378345A1

公开(公告)日：2024-11-14

申请号：US18691657

申请日：2022-09-27

Applicant: JFE STEEL CORPORATION

Inventor： Yusuke FUJII ,  Taira NAKAMOTO ,  Masaki URABE

IPC: G06F30/23 ,  G06F113/24 ,  G06F119/14

Abstract: A method of predicting a shape change of a press-formed product, includes: generating a blank model which is divided into a plurality of pieces in a sheet thickness direction such that the blank model can be analyzed; acquiring a shape and residual stress in the sheet thickness direction of the press-formed product immediately after the spring back by performing press forming analysis and spring back analysis using the blank model and a die model; setting a value of residual stress relaxed and reduced to an element or an integration point of a sheet thickness surface layer of the press-formed product immediately after spring back; and determining a shape in which moment of force is balanced in the press-formed product for which a value of residual stress of only the sheet thickness surface layer has been set to be relaxed and reduced.

公开(公告)号：US20240207917A1

公开(公告)日：2024-06-27

申请号：US18288708

申请日：2022-02-14

Applicant: JFE STEEL CORPORATION

Inventor： Taira NAKAMOTO ,  Akinobu ISHIWATARI

IPC: B21D22/02

CPC classification number: B21D22/02

Abstract: A press forming method reduces a time for chronological shape variation of a press formed part after occurrence of springback at a moment when the press formed part is released from a die, and includes: forming the press formed part by press forming with a metal sheet by using the die; releasing the press formed part formed by press forming, from the die; fitting the press formed part released from the die into the die and securing the press formed part in conformity with a shape at a bottom dead center of forming; heating the press formed part fitted into the die to a first temperature higher than room temperature and holding the press formed part at the first temperature for a predetermined time period of less than 30 minutes; and cooling the press formed part heated and held, to a second temperature lower than the first temperature.

公开(公告)号：US20240198405A1

公开(公告)日：2024-06-20

申请号：US18287714

申请日：2022-02-14

Applicant: JFE STEEL CORPORATION

Inventor： Taira NAKAMOTO

IPC: B21D17/02 ,  B21D5/01

CPC classification number: B21D17/02 ,  B21D5/01

Abstract: A press forming method for a press formed part includes: placing a pre-unbending press formed part on a punch including a top forming surface portion configured to form a top portion of the press formed part, and side-wall forming surface portions configured to form side wall portions, each of the side-wall forming surface portions including a punch side first sloped surface portion, and a punch side second sloped surface portion; relatively moving a die toward the punch, the die including flange unbending portions; and unbending flange portions by the flange unbending portions while punch side ridge line portions are brought into contact with inner surface sides of the side wall portions to form the side wall portions of the press formed part.