COLD FORMING METHOD OF RIM IN ALLOY WHEEL FOR VEHICLE

摘要

PURPOSE: A cold forming method of a rim in an alloy wheel is provided to reduce a number of processes, to simplify a producing tool and to improve the productivity and the yield rate. CONSTITUTION: A seamless tube is obtained by forming a cup shaped preform. A unit tube is obtained by cutting the seamless tube. A preform unit tube is formed by primally roll-forming the unit tube with a primary roller(48) in a roll forming machine(40). A rim portion is formed by secondarily roll-forming the preform unit tube with a secondary roller(50). Thereby, a size change is prevented and the welding intensity is increased.