Burring processed member
AssigneeNippon Steel Corporation
InventorsKohei NAKADA, Ryo TABATA, Takeshi KAWACHI, Takeshi TOYODA
Life of this patent
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Abstract
As a burring processed member able to suppress the formation of fatigue cracks in a burring part, one having a structure satisfying the following relations (1) to (3) is disclosed: 3≤Ra≤100 . . . (1), 3.0<h . . . (2), 24+r−[TS/(40+0.28×Ra)]<h . . . (3), where, “Ra” is an arithmetic mean roughness (μm) of the burring end face, “h” is a height (mm) from the first surface to the burring end face, “r” is a radius of curvature (mm) of the curved wall part, and “TS” is the tensile strength (MPa) of the sheet-shaped part.
Claims5
A burring processed member comprising a sheet-shaped part and a burring processed part, wherein
- the sheet-shaped part has a first surface at one side and a second surface at an opposite side to the first surface,
- the burring processed part a burring wall part,
- the burring wall part sticks out to one side from the first surface,
- the burring wall part has a vertical wall part and a curved wall part,
- the vertical wall part has a burring end face at one side and is connected to the curved wall part at an opposite side to the one side,
- the curved wall part is connected to the vertical wall part at one side and is connected to the sheet-shaped part at an opposite side to the one side, and
- the burring processed part has a structure satisfying the following relations (1) to (3):
- 3≤Ra≤100 (1)
- 3.0<h (2)
- 24+r−[TS/(40+0.28×Ra)]<h (3)
- where,
- “Ra” is an arithmetic mean roughness (μm) of the burring end face,
- “h” is a height (mm) from the first surface to the burring end face,
- “r” is a radius of curvature (mm) of the curved wall part, and
- “TS” is the tensile strength (MPa) of the sheet-shaped part.
Dependencies are inferred from the claim text.