Press forming method and shape evaluation method for press formed part

Patent metadata

Field	Value
Publication number	US-2024207917-A1
Application number	US-202218288708-A
Country	US
Kind code	A1
Filing date	Feb 14, 2022
Priority date	May 6, 2021
Publication date	Jun 27, 2024
Grant date	—

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.

First claim

1 - 7 . (canceled)

8 . A press forming method for reducing 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, the method comprising:
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.

9 . The press forming method according to claim 8 , wherein the first temperature is 130° C. to 150° C., and the predetermined time period is one minute or more and three minutes or less.

10 . A press forming method for reducing 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, the method comprising:
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 whole or part of the press formed part released from the die, to a jig configured to hold the press formed part in a predetermined shape, including another die having a same shape as that of the die, and securing the whole or part of the press formed part in conformity with the predetermined shape, or predicting a shape of the press formed part after occurrence of springback due to die release, by measurement or calculation, fitting whole or part of the press formed part released from the die, to a jig configured to hold the press formed part in a same shape as the shape after springback due to die release, and securing the whole or part of the press formed part in conformity with the shape after springback; heating the press formed part fitted to the jig 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.

11 . The press forming method according to claim 10 , wherein the first temperature is 130° C. to 150° C., and the predetermined time period is one minute or more and three minutes or less.

12 . A press forming method for reducing 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, the method comprising:
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; heating the press formed part released from 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.

13 . The press forming method according to claim 12 , wherein the first temperature is 130° C. to 150° C., and the predetermined time period is one minute or more and three minutes or less.

14 . The press forming method according to claim 12 , further comprising evaluating a shape of the press formed part to be fabricated with other parts after the cooling, wherein the evaluating includes:
measuring a shape of the press formed part after the cooling; and determining to subject the press formed part to a fabricating process, when the measured shape of the press formed part is within a preset predetermined range.

15 . The s press forming method according to claim 14 , wherein the first temperature is 130° C. to 150° C., and the predetermined time period is one minute or more and three minutes or less.

Assignees

• Jfe Steel Corp

Inventors

• Nakamoto Taira
• Ishiwatari Akinobu

Classifications

• B21D37/08

  Dies with different parts for several steps in a process · CPC title

• B21D22/208

  by heating the blank or deep-drawing associated with heat treatment (C21D takes precedence) · CPC title

• C21D9/0062

  Heat-treating apparatus with a cooling or quenching zone · CPC title

• B21D5/01

  between rams and anvils or abutments · CPC title

• B21D37/16

  Heating or cooling · CPC title