Method for producing damper pulley

A method for producing a damper pulley having a boss portion constructed and arranged to be press-fitted onto a rotary shaft, an annular main portion extending from said boss portion, a flange portion formed along an outer periphery of said main portion, a ring-shaped damper-mass member located about said flange portion, and a rubber body interposed between said flange portion and said damper-mass member, the method comprising the sequential steps of:

• forming said boss portion, said main portion and said flange portion integrally from a metallic plate such that at least one part of said main portion has a curved section and a radial length of said main portion is greater than a straight line distance between said boss portion and said flange portion;
• placing said rubber body between said flange portion and said damper-mass member;
• and
• enlarging a diameter of said flange portion to elongate said at least one part of said main portion having the curved section, thereby substantially straightening said curved section and pressing said rubber body by the enlarged flange portion.