US 12,070,787 B2
Press forming method and press apparatus
Minoru Sugawara, Tokyo (JP); Yasuharu Tanaka, Tokyo (JP); Takashi Miyagi, Tokyo (JP); Misao Ogawa, Tokyo (JP); and Junki Natori, Tokyo (JP)
Assigned to NIPPON STEEL CORPORATION, Tokyo (JP)
Appl. No. 17/425,614
Filed by NIPPON STEEL CORPORATION, Tokyo (JP)
PCT Filed Jan. 24, 2020, PCT No. PCT/JP2020/002618
§ 371(c)(1), (2) Date Jul. 23, 2021,
PCT Pub. No. WO2020/153500, PCT Pub. Date Jul. 30, 2020.
Claims priority of application No. 2019-011631 (JP), filed on Jan. 25, 2019.
Prior Publication US 2022/0097116 A1, Mar. 31, 2022
Int. Cl. B21D 22/22 (2006.01); B21D 19/08 (2006.01); B21D 24/04 (2006.01); B21D 53/88 (2006.01)
CPC B21D 22/22 (2013.01) [B21D 19/08 (2013.01); B21D 24/04 (2013.01); B21D 53/88 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A press forming method in which, assuming a thickness direction of a metal sheet to be a pressing direction, a die is arranged on one side of the metal sheet in the pressing direction, and a pad and a punch are arranged on another side of the metal sheet in the pressing direction, and press forming is performed on the metal sheet by means of the die, the pad and the punch, the method comprising:
a first step of pinching one part of the metal sheet by means of the die and the pad, and
a second step of, in a state in which the one part of the metal sheet is pinched by the die and the pad, moving the punch in a direction in which the punch approaches the die in the pressing direction relatively to perform press forming on the metal sheet, wherein:
the die has a first support surface which faces the pad in the pressing direction and which has an edge including a curved portion that curves so as to be recessed in an arc shape as viewed from the pressing direction, and a wall surface extending to the one side in the pressing direction from the edge of the first support surface;
the pad has a second support surface which faces the first support surface in the pressing direction;
the punch is provided on an opposite side to the first support surface with respect to the wall surface as viewed from the pressing direction;
the first support surface includes a first flat portion which extends in an orthogonal direction to the pressing direction, and a first deformation portion which protrudes or is recessed with respect to the first flat portion in the pressing direction;
the second support surface includes a second flat portion which faces the first flat portion in the pressing direction, and a second deformation portion which is recessed or protrudes with respect to the second flat portion so as to correspond to the first deformation portion;
the first deformation portion is provided on a normal line of the curved portion, as viewed from the pressing direction;
the first flat portion is provided continuously on both sides of the first deformation portion in a direction along the curved portion, as viewed from the pressing direction; and
when a space between the first deformation portion and the second deformation portion is assumed to be a deformation space,
in the second step, press forming is performed so that portions of the metal sheet which are on both sides of the deformation space in the direction along the curved portion as viewed from the pressing direction flow into the deformation space, and the metal sheet deforms along the first deformation portion and the second deformation portion in the deformation space.