method of construction of a pulley for use with a motor vehicle and similar cultural's throats peripheral v

摘要

A method for producing a pulley (1) for motor vehicle applications and the like provided with a plurality of V-shaped peripheral races (7) is described; the method is carried out from a flat disc (11) and comprises the steps of: a) performing a drawing operation on the disc (11) to obtain a first cup-shaped semifinished product (12) having a flat base wall (13) and a side wall (14) joined to the base wall (13); b) obtaining a through-bore (16) through the base wall (13) of the first semifinished product (12); c) plastically deforming the first semifinished product (12) so as to fold an end portion, opposite to the bore (16), of the side wall (14) towards the axis (A) of the first semifinished product (12) obtaining a second semifinished product (17); d) plastically deforming the second semifinished product (17) radially compressing it so as to reduce the differences in diameter between the axial sections thereof; and e) roll forming the races (7) on the outer surface of the body obtained thereby.