Patent ID: 6338197
Filing Date: 2002-01-15
Classification: B21D,B21H,Y10T

Abstract:
A method of manufacturing a multi-stage pulley (100) having a plurality of groove sections (103) integrally formed with each other and adapted for engagement with driving belts, the method comprising:a preliminary groove forming process in which, while a pushing roller (204) is pushed against a substantially cup-shaped work-piece (W2), a first space between portions of a circumferential outer wall section of the substantially cup-shaped work-piece (W2) corresponding to a first groove section (103a) of the plurality of groove sections (103) is pushed by a first preliminary groove-forming roller (206a) and a second space between portions of the circumferential outer wall section of the substantially cup-shaped work-piece (W2) corresponding to a second groove section (103b) of the plurality of groove sections (103) is pushed by a second preliminary groove forming roller (206b) and so as to preform both first and second groove sections (103a, 103b) of the plurality of groove sections (103); and a groove forming finishing process in which, while the pushing roller (204) is pushed against the substantially cup-shaped work-piece (W2), the first space between portions of the circumferential outer wall section of the substantially cup-shaped work-piece (W2) corresponding to the first groove section (103a) of the plurality of groove sections (103) is pushed by a first finishing-groove forming roller (207a) and the second space between portions of the circumferential outer wall section of the substantially cup-shaped work-piece (W2) corresponding to the second groove section (103b) of the plurality of grooves sections (103) is pushed by a second finishing groove-forming roller (207b) so as to finish both first and second groove sections (103a, 103b) of the plurality of groove sections (103); wherein, in the groove forming finishing process, the first and second finishing groove-forming rollers (207a, 207b) are arranged so that portions of the substantially cup-shaped work-piece (W2) corresponding to both first and second groove sections (103a, 103b) of the plurality of grooves sections (103) to be pushed in the case of forming and finishing the first groove section (103a) and the second groove section (103b) can be shifted from each other in the circumferential direction of the substantially cup-shaped work-piece (W2), and the first groove section (103a) and the second groove section (103b) are simultaneously formed and finished.