Press forming method, and method for manufacturing press-formed part

Patent metadata

Field	Value
Publication number	US-10220428-B2
Application number	US-201415106724-A
Country	US
Kind code	B2
Filing date	Oct 21, 2014
Priority date	Dec 20, 2013
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

A press forming method forms a metal plate into the part shape having at least a top surface portion and side wall portions continuous with both left and right sides of the top surface portion, the part shape having a U-shaped or hat-shaped cross section and having one or two or more bent portions bent in a longitudinal direction that is a direction intersecting the cross section. The press forming method includes: a first step of applying in-plane shear deformation to a plate portion on both sides or one side of the bent portions in the longitudinal direction of the metal plate, the in-plane shear deformation corresponding to a direction of bending the portion of the part shape; and a second step of implementing press forming for the metal plate into the part shape, the metal plate to which the in-plane shear deformation has been applied.

First claim

The invention claimed is:

1. A press forming method for forming a metal plate into a part shape, the part shape having:
at least a top surface portion and side wall portions that are continuous with the top surface portion,
a U-shaped or hat-shaped cross section, and
one or more bent portions that are bent in a longitudinal direction of the metal plate,
the press forming method comprising:
a first step of applying in-plane shear deformation to a metal plate portion on either (i) a first side of the metal plate or (ii) the first side and a second side of the metal plate, the in-plane shear deformation being applied in the longitudinal direction of the metal plate, and
a second step of applying press forming on the metal plate, after the first step, and forming the part shape, the press forming being applied on the first side and the second side of the metal plate,

wherein:
in the first step, the in-plane shear deformation is caused by applying tensile force between a first loaded portion and a second loaded portion and is caused by draw forming by a punch,
the first loaded portion corresponding to the top surface portion of the part shape, and
the second loaded portion being spaced apart from the first loaded portion in the longitudinal direction and corresponding to at least one of the side wall portions of the part shape or on a portion of the part shape that is outside of the side wall portions in a width direction of the part shape,

a profile of a shoulder portion of the punch for use in the draw forming, the profile going along a circumferential direction of the punch, has an outline shape in which a center side portion, which abuts against a center portion side position in the plate width direction of the metal plate, and an end edge portion, which abuts against an end portion in the plate width direction of the metal plate, are spaced apart from each other in the longitudinal direction such that a spacing between the center side portion and the end edge portion becomes larger when going from the center side portion toward the end edge portion, and
a profile of a shoulder portion of a die for use in the draw forming has an outline shape similar to the profile of the shoulder portion of the punch.

2. The press forming method according to claim 1 , wherein, in the second step:
the one or more bent portions are formed so that the top surface portion either protrudes or is recessed, and
the first side of the metal plate and the second side of the metal plate become the side wall portions.

3. The press forming method according to claim 1 , wherein:
the part shape has two or more bent portions that are spaced apart from each other in the longitudinal direction, and
the in-plane shear deformation of the first step is applied between first and second positions, the first and second positions corresponding to the one or more bent portions of the part shape.

4. The press forming method according to claim 1 , wherein 0.01<ΔD/ΔW<10 is satisfied in a case where the spacing between the center side portion and the end edge portion is defined as ΔD, and a distance in the plate width direction between the center side portion and the end edge portion is defined as ΔW.

5. The press forming method according to claim 1 , wherein a gap between the punch and a hole of the die, which are used in the first step, is set to 0.5 times or more to 1.5 times or less a plate thickness of the metal plate.

6. The press forming method according to claim 1 , wherein the profile of the shoulder portion of the punch includes a parallel portion on a center side in the plate width direction of the metal plate, the parallel portion being extended in the plate width direction of the metal plate, and the center side portion is located on an end portion of the parallel portion.

7. The press forming method according to claim 6 , wherein, in the profile of the shoulder portion of the punch, a profile between the center side portion and the end edge portion is formed linear or circular-arc.

8. The press forming method according to claim 6 , wherein the parallel portion abuts against a metal plate position that becomes the top surface portion.

9. The press forming method according to claim 1 ,
wherein, in the second step, the press forming includes using foam forming or draw forming to form the part shape.

10. The press forming method according to claim 9 , wherein, in the second step during the foam forming or the draw forming, a first position is restrained from moving and a second position is sandwiched by a pad and a punch, the first position and the second position both corresponding to the top surface portion of the part shape.

11. The press forming method according to claim 9 , wherein:
the one or more bent portions of the part shape include a first bent portion, in which the top surface portion protrudes, and a second bent portion, in which the top surface portion is recessed.

Assignees

• Jfe Steel Corp
• Jfc Steel Corp

Inventors

• Fujii Yusuke
• Shinmiya Toyohisa
• Iizuka Eiji
• Yamasaki Yuji

Classifications

• B21D53/88

  other parts for vehicles, e.g. cowlings, mudguards · CPC title

• B21D22/26 Primary

  for making peculiarly, e.g. irregularly, shaped articles · CPC title

• B21D22/201

  Work-pieces; preparation of the work-pieces, e.g. lubricating, coating · CPC title