Jfe Steel Corporation

H-one Co., Ltd.

Nippon Steel Sumitomo Metal Corporation

Daisuke Toyoda

Toyohisa Shinmiya

Hiroto Miyake

Hiroyuki Takebe

Youichi Konkawa

Tohru Yoshida

A punch and a pad sandwiching a top sheet portion, bending blades for bend-forming the vertical wall portions, and stoppers facing the bending blades are provided. The punch is supported by a first cushion component. The bending blades each have an upper die component and a lower die component disposed facing each other in the press direction with an interval equal to a set compression amount in the range of 2% or more and 6% or less of the heights of the vertical wall portions and a second cushion component interposed between the upper die component and the lower die component, maintaining the interval, and contractible in the press direction. The cushion pressure of the second cushion component is lower than the cushion pressure of the first cushion component and has such cushion pressure that the second cushion component does not contract during the bend-forming of the vertical wall portions.

Press form device and method for producing press-formed articles

To reduce warping of vertical wall portions without causing buckling during pressing. Press-forming into a hat cross-sectional shape having one linear vertical wall portion and the other curved vertical wall portion and not having a flange portion is performed. A punch and a pad sandwiching a top sheet portion therebetween, bending blades, and stoppers are provided. The punch is supported by a first cushion component. The bending blades each have an upper die component and a lower die component disposed facing each other in the press direction with an interval (D) equal to a set compression amount in the range of 2% or more and 6% or less of the heights of the vertical wall portions and a second cushion component interposed between the upper die component and the lower die component, maintaining the interval (D), and contractible in the press direction. The cushion pressure of the second cushion component is lower than the cushion pressure of the first cushion component and has such cushion pressure that the second cushion component does not contract during the bend-forming of the vertical wall portions. The clearance between the side surface of the punch and the bending blades is 90% or more of the sheet thickness of a material to be processed and less than the sheet thickness.

A load-applying device of a press-forming die includes a rod which includes a first end, a second end, and a flange, a lamination coned disc spring in which a plurality of coned disc springs having a center hole, to which the first end of the rod is inserted, are laminated, a first plate which includes a first through hole to which the first end of the rod is inserted and abuts the lamination coned disc spring, a second plate which includes a second through hole to which the second end of the rod is inserted and abuts the flange; and a gap fixing member which is detachably provided between the first plate and the second plate and fixes a gap between the first plate and the second plate so as to maintain the gap by which the lamination coned disc spring biases the flange to the second plate. The second end and the first plate relatively move in a mutually approaching direction during press-forming, and the lamination coned disc spring is compressed.

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Tochigi, Japan

Daisuke Toyoda