METHOD FOR FORMING DOUBLE-HEADED PULLEY FOR AUTOMOBILE BY USING SEMI-HERMETIC COLD FORGING AND THREE-DIMENSIONAL OPENING/CLOSING

摘要

PURPOSE: A method for manufacturing a belt hanging double-headed integral pulley that is an essential part out of components composing ADS (accessory drive system) for automobile by using cold forging method is provided. CONSTITUTION: In a method for manufacturing a pulley(10), the method for forming a double-headed pulley for automobile by using semi-hermetic cold forging and three-dimensional opening/closing comprises the steps of producing first molding(10') using semi-hermetic die sets; and producing second molding(10") using three-dimensional opening/closing type die sets, wherein size of the outer diameter and filling ratio of the inner diameter of the pulley(10) are appropriately controlled through tension adjustment of spring and height adjustment of limit block of the semi-hermetic die sets, and the three-dimensional opening/closing type die sets support forming of the pulley(10) and ejects the pulley(10) since the three-dimensional opening/closing type die sets are gathered during descent of the inserts while they are opened during ascent of the inserts as the split inserts are interlockingly being connected to a holder.