Blank, formed article, die assembly, and method for producing blank
AssigneeNippon Steel & Sumitomo Metal Corporation
InventorsTakashi MATSUNO, Akira EGAMI
Life of this patent
Estimating the term…
Abstract
A sheet-shaped blank (10) for press forming is produced by shearing a metal sheet (30). The blank (10) includes a sheared edge (14), which includes a sheared surface (14b) and a fractured surface (14c) in the sheet thickness direction and has a loop shape in plan view. In plan view, an edge of the sheared edge (14) includes concavely curved portions (20). The average of lengths of the fractured surface (14c) in the sheet thickness direction in the curved portions (20) is greater than the average of lengths of the fractured surface (14c) in the sheet thickness direction over the entire perimeter of the sheared edge (14).
Claims19
A sheet-shaped blank for press forming produced by shearing a metal sheet, the blank comprising:
- a sheared edge comprising, in a sheet thickness direction, a sheared surface and a fractured surface, wherein
- the sheared edge has a loop shape in plan view,
- the sheared edge has an edge comprising, in plan view, a curved portion that is concavely curved, and
- an average of lengths of the fractured surface in the sheet thickness direction in the curved portion is greater than an average of lengths of the fractured surface in the sheet thickness direction over an entire perimeter of the sheared edge.
A die assembly comprising:
- a columnar punch;
- and
- a hollow die configured to receive the punch,
- the die assembly being configured to shear a metal sheet placed on the die by moving the punch in a predetermined direction,
- the punch comprising a bottom surface and an outer perimeter surface, the bottom surface comprising a cutting edge constituted by an outer perimeter edge of the bottom surface, the outer perimeter surface extending from the outer perimeter edge in a direction parallel to the predetermined direction,
- the outer perimeter edge comprising, in plan view, a curved portion that is convexly curved or concavely curved,
- the bottom surface comprising a planar portion and a cutout portion recessed with respect to the planar portion in the predetermined direction and configured to comprise the curved portion in plan view.
A die assembly comprising:
- a columnar punch;
- and
- a hollow die configured to receive the punch,
- the die assembly being configured to shear a metal sheet placed on the die by moving the punch in a predetermined direction,
- the die comprising a hollow support surface and an inner perimeter surface, the support surface being configured to support the metal sheet and comprising a cutting edge constituted by an inner perimeter edge of the die, the inner perimeter surface extending from the inner perimeter edge in a direction parallel to the predetermined direction,
- the inner perimeter edge comprising, in plan view, a curved portion that is convexly curved or concavely curved,
- the support surface comprising a planar portion and a cutout portion recessed with respect to the planar portion in the predetermined direction and configured to comprise the curved portion in plan view.
Dependencies are inferred from the claim text.