Nut, female thread machining device and female thread machining method
AssigneeHonda Motor Co., Ltd.
InventorsYota Eguchi, Hiroki Fujiuchi, Naoki Takahashi, Toshihiro Murakawa
Life of this patent
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Abstract
There is provided a nut having a thread portion having a female thread, a metallic plate portion having a base segment, and a hardness gradient portion provided between the thread portion and the metallic plate portion. The thread portion, metallic plate portion and the hardness gradient portion are monolithic each other, a metallographic structure of the metallic plate portion differs from a metallographic structure of the thread portion and a hardness of the hardness gradient portion is lower than a hardness of the thread portion and lowers from the thread portion toward the metallic plate portion.
Claims19
A nut comprising:
- a thread portion having a female thread;
- a metallic plate portion having a base segment;
- and
- a hardness gradient portion provided between the thread portion and the metallic plate portion,
- wherein the thread portion, metallic plate portion and the hardness gradient portion are monolithic each other,
- a metallographic structure of the metallic plate portion differs from a metallographic structure of the thread portion and
- a hardness of the hardness gradient portion is lower than a hardness of the thread portion and lowers from the thread portion toward the metallic plate portion.
A nut comprising:
- a female thread provided on a penetrating hole of the nut;
- a base end portion which is provided at one axial end of the nut and has a seat surface adapted to be contact with a component to be fastened;
- a tip end portion provided on the other axial end of the nut;
- a diameter reducing side portion provided between the base end portion and the tip end portion and a diameter of which decreasing from the base end portion toward the tip end portion;
- and
- a concave segment provided on the seat surface of the base end portion so as to include an area where the penetrating hole is opened.
A female thread machining device comprising:
- a heating unit which heats a region where a female thread is to be formed in a metallic plate;
- a machining tool which forms the female thread in the metallic plate;
- a cooling unit which cools the machining tool;
- a rotation-driving unit which rotates the machining tool;
- and
- an advance/retract driving unit which advances or retracts the machining tool.
A female thread machining method comprising:
- a heating step of, by a heating unit, heating a region of a metal plate where a female thread is formed;
- a cooling step of cooling a machining tool, which is adapted to form the female thread in the metallic plate, by a cooling unit;
- and
- a machining step comprising:
- stopping heating the metal plate by the heating unit and continuing cooling the machining tool by the cooling unit;
- inserting the machining tool into the metallic plate while rotating the machining tool;
- and
- forming the female thread by the machining tool while cooling the metallic plate by the machining tool.
Dependencies are inferred from the claim text.