MANUFACTURING METHOD OF DOUBLE PULLEY

摘要

PURPOSE: A manufacturing method of the double pulley is provided to manufacture a double pulley around which two V-belts are wound by preparing a circular material, cutting out thickness of the material and forming both pipe parts of the thickness cut out material by cold forming method, thereby forming belt grooves on the pipe parts. CONSTITUTION: The method comprises first step of forming a pipe part at both sides of the thickness cut out pulley material by cutting out thickness of the pulley material in the state that the pulley material is rotated after preparing a pulley material(10) by cutting an iron plate in a circular shape and perforating shaft hole at the center of the circular iron plate; second step of forming a preliminary belt groove on the pipe part formed in the first step by a preliminary belt groove forming tool; third step of forming the preliminary belt groove in such a way that depth of the preliminary belt groove approaches standard dimensions by pressing side cross section of the preliminary belt groove formed in the second step by press(140); and fourth step of forming a belt groove(14) corresponding to standard dimensions by pressing a belt groove forming tool(130) on the preliminary belt groove formed in the third step, wherein the belt groove having uniform thickness and accurate size is formed by forming the preliminary belt groove in the state that the inner circumferential surface of the preliminary belt groove is supported by supporting guide(160) when pressing the belt groove forming tool on the outer circumferential surface of the preliminary belt groove formed in the fourth step.