| 摘要 |
A toothed wheel is cold formed from a circular piece or plate of sheet metal by cold-forming an annular outer section of the sheet metal into a preform, while the sheet metal is held in a rotary holding unit and rotated about its preform axis. While the sheet metal is rotating, a thickening roller works against the sheet metal's an outer annular section to thicken the same and form a wheel having a generally uniform cross-sectional outer annular section and an integral central wall that extends radially inwardly from the outer annular section. The outer annular section is formed by a multi-stage cold rolling process, utilizing different thickening rollers. Then, while the preform is rotating, a curling roller works on the outer annular section to form an axially extending flange, forming a cylindrical or C-shaped wheel to form a final preform. Then, while the final preform is rotating, a tooth forming roller is meshed against the outer periphery of the flange. At the same time, a back-up roller engages the flange at a different location to further shape the flange.
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