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US 5,746,085 AGranted
Gear forming method
AssigneeHitachi, Ltd.
InventorsKoji Harada, Hisanobu Kanamaru
Life of this patent
Estimating the term…
Abstract
A method of forming a gear through cold plastic working comprises preparing a disc-like blank, and pressing conically a central portion of the blank with a uniform pressure from upper and lower sides to cause plastic deformation in the blank thereby to form a gear along a gear-shaped die arranged around the periphery of the blank. The blank material is restrained to flow radially at peripheral end faces of the blank during the forming of the gear.
Claims9
A method of forming a gear through cold plastic working, comprising the steps of:
- disposing a disc-like blank in a gear die having a gear-shaped inner periphery so that an outer side periphery of the blank is surrounded by the gear-shaped inner periphery of the gear die;
- holding peripheral portions of both upper and lower end faces of a blank using a pair of constraint members to constrain axial plastic flow of the material of the blank in the peripheral portions of the upper and lower end faces of the blank;
- and
- pressing concentrically on the upper and lower end faces of the blank with a pair of punches arranged and moved in opposite relation while restraining axial plastic flow in the peripheral portion of the blank and allowing radial plastic flow of the material into the gear die, thereby to form a gear, each of the punches having a diameter equal to or less than a small diameter of the gear die and having a tapered portion at a tip thereof.
1 more element
A method of forming a gear through cold plastic working, comprising the steps of:
- disposing a blank in a gear die;
- holding peripheral portions of both upper and lower end faces of a blank using a pair of constraint members to constrain axial plastic flow of the material of the blank in the peripheral portions of the upper and lower end faces of the blank;
- pressing concentrically on the upper and lower end faces of the blank with a pair of punches arranged in opposite relation while restraining axial plastic flow in the peripheral portions of the upper and lower end faces of the blank, each of the punches having a diameter equal to or less than a small diameter of the gear die arranged around a periphery thereof and a tapered portion at a tip thereof to cause radial plastic flow of the material into the gear die, thereby to form an intermediate gear;
- punching the intermediate gear;
- and then
- inserting the punched intermediate gear in a gear die to effect sizing formation by gear-shaped punches or a mandrel.
3 more elements
Dependencies are inferred from the claim text.