Hot-stamping formed article, vehicle member, and manufacturing method of hot-stamping formed article
AssigneeNippon Steel Corporation
InventorKenichiro Otsuka
Life of this patent
Estimating the term…
Abstract
A hot-stamping formed article is formed of a single steel sheet, and includes: a top sheet portion; a pair of standing wall portions; and a protrusion portion which connects the top sheet portion to the standing wall portion and protrudes outward from the top sheet portion, in which the protrusion portion includes an inner wall portion which stands upright from the top sheet portion, and an outer wall portion which is folded outward from an end edge of the inner wall portion, and an angle between the top sheet portion and the protrusion portion is 80° to 90°.
Claims11
A hot-stamping formed article formed of a single high tensile strength steel sheet, comprising:
- a top sheet portion;
- a pair of standing wall portions;
- and a protrusion portion which connects the top sheet portion to one of the pair of standing wall portions and protrudes outward from the top sheet portion, wherein the protrusion portion includes an innerwall portion which stands upright from the top sheet portion, and an outer wall portion which is folded outward from an end edge of the innerwall portion and overlaps the innerwall portion, and an angle between the top sheet portion and the protrusion portion is 80° to 90°, and a martensite fraction of at least the protrusion portion is 90% or more, and wherein the innerwall portion and the outer wall portion of the protrusion portion abut each other.
A manufacturing method of the hot-stamping formed article formed of a single sheet comprising:
- a top sheet portion;
- a pair of standing wall portions;
- and
- a protrusion portion which connects the top sheet portion to one of the pair of standing wall portions and protrudes outward from the top sheet portion,
- wherein the protrusion portion includes
- an inner wall portion which stands upright from the top sheet portion, and
- an outer wall portion which is folded outward from an end edge of the inner wall portion, and
- an angle between the top sheet portion and the protrusion portion is 80° to 90°, the manufacturing method comprising:
- a preparation step of obtaining a preliminary formed article, in which a recessed part is formed, by pressing a base steel sheet;
- a heating step of heating the preliminary formed article;
- and
- a press-forming step of forming the preliminary formed article into the hot-stamping formed article by performing press working on the heated preliminary formed article,
- wherein, in the press-forming step, a pressing apparatus including a lower die having a protrusion, an upper die which has a punch portion that presses the preliminary formed article and is movable in a vertical direction toward the lower die, and a pair of slide dies which cause the protrusion of the lower die to be interposed between the slide dies and are movable in a horizontal direction toward side surfaces of the protrusion of the lower die is used,
- the preliminary formed article is placed in the pressing apparatus so as to cause the protrusion of the lower die to protrude in the recessed part of the preliminary formed article and the preliminary formed article is not to be brought into contact with the protrusion of the lower die, the punch portion, and the pair of slide dies, and
- the preliminary formed article is pressed by moving the punch portion and the pair of slide dies.
A manufacturing method of the hot-stamping formed article formed of a single steel sheet, comprising:
- a top sheet portion;
- a pair of standing wall portions;
- a protrusion portion which connects the top sheet portion to one of the pair of standing wall portions and protrudes outward from the top sheet portion;
- and
- a pair of flange portions which are connected to end portions of the pair of standing wall portions and extend so as to be separated from each other,
- wherein the protrusion portion includes
- an inner wall portion which stands upright from the top sheet portion, and
- an outer wall portion which is folded outward from an end edge of the inner wall portion, and
- an angle between the top sheet portion and the protrusion portion is 80° to 90°, the hot-stamping formed article being manufactured by using a pressing apparatus including a lower die having a protrusion and a pair of movable plates that cause the protrusion to be interposed between the movable plates and are movable in a vertical direction, a punch die which is movable in the vertical direction toward the protrusion, and a pair of movable dies which cause the punch die to be interposed between the movable dies and are movable toward the movable plates and the protrusion, the manufacturing method comprising:
- a step of heating a base steel sheet;
- a step of placing the heated base steel sheet on the pair of movable plates so as not to be brought into contact with the protrusion;
- a step of forming the base steel sheet into a deformed steel sheet having a recessed part by lowering the pair of movable dies while abutting the base steel sheet;
- a step of pressing the deformed steel sheet by moving the punch die toward the protrusion;
- and
- a step of pressing the deformed steel sheet by moving the pair of movable dies toward the punch die.
Dependencies are inferred from the claim text.