| 摘要 |
A pulley making method and apparatus for forming a pulley having a pulley groove of given cross section defined by flange walls connected through the root of the groove, the groove having a given root diameter, from a pulley blank in the form of a sheet metal cup having an annular bulge in the cup wall and an adjacent flaring wall portion, with a valley defined between the bulge and adjacent flaring wall portion. A pulley is formed from the blank by engaging the flaring wall portion and the side of the bulge remote from the valley with axially movable dies and moving the dies together to crush the bulge and form it into a double wall. Groove-forming rolls are positioned within the valley so that they extend radially inwardly to an imaginary circle having a diameter equal to the root diameter prior to the attainment of a final forming position by the axially movable dies. Relative rotation is established between the pulley blank and the group of rolls and the rolls roll within the valley to receive the axial thrust of the bulge as its crushing is completed, and to keep the valley clear as its shape approaches and conforms to the desired pulley groove cross section. |
