Patent ID: 6381847
Filing Date: 2002-05-07
Classification: B21D,B21H,B21K,Y10T

Abstract:
A method of manufacturing a poly-V pulley including a small-diameter cylindrical portion, a supporting base portion, and a large-diameter cylindrical portion, the small-diameter cylindrical portion having a small-diameter poly-V groove on an outer surface thereof, the supporting base portion having a shaft insertion hole at the center thereof, and the large-diameter cylindrical portion having a large-diameter poly-V groove on the outer surface thereof, which is disposed consecutively and concentrically with the small-diameter cylindrical portion via a stepped portion on the other end in the axial direction of the small-diameter cylindrical portion, comprising the steps of:bending a circular flat-plate material provided with the shaft insertion hole at the center thereof, thereby forming a first forming body whose section is dish-shaped, including the supporting base portion and a conical peripheral wall which extends outwardly from an outer end of the supporting base portion, and widening in its outward extent, extending the conical peripheral wall in its widening outward extent, and decreasing the thickness thereof, thereby forming a second forming body whose section is deep dish-shaped, drawing the conical peripheral wall of the second forming body, whose thickness is decreased, thereby forming the small-diameter cylindrical portion and the large-diameter cylindrical portion, and roll-shaping respectively the small-diameter poly-V groove on the outer periphery of the supporting base portion and the outer surface of the small-diameter cylindrical portion, and the large-diameter poly-V groove on the outer surface of the large-diameter cylindrical portion.