METHOD FOR MANUFACTURING BODY MEMBER OF VEHICLES BY BENDING, RIGIDITY REINFORCEMENT AND DIMENSION AND SHAPE CORRECTION AFTER FORMING EXTRUDED ALUMINUM PIPE INTO WORKPIECE CONSIDERING FUNCTIONAL AND STRUCTURAL CHARACTERISTICS

摘要

PURPOSE: To provide a method for manufacturing a body member of vehicles that has superior forming accuracy and dimensional quality, maintains structural rigidity and contributes to lightening of the car body by performing processes of bending, rigidity reinforcement and dimension and shape correction after forming an extruded aluminum pipe into a workpiece considering functional and structural characteristics. CONSTITUTION: The method for manufacturing body member of vehicles comprises a product and workpiece design step simply designing products and workpieces using pipes by calculating an average value of overall cross-sectional variation of an existing car body member; an extrusion step of forming an extruded aluminum pipe by extruding an aluminum ingot by an extruder; a bending step of performing first bending forming on a principal bending portion of the extruded aluminum pipe formed in the extrusion step by a bending machine; a reinforcement heat treatment step of reinforcing rigidity of the extruded aluminum pipe by heat treating the extruded aluminum pipe obtained after performing the first bending forming on the principal bending portion of the extruded aluminum pipe in the bending step; a dimension and shape correction step of performing second bending forming on the extruded aluminum pipe obtained after reinforcing rigidity of the extruded aluminum pipe by a hydroforming equipment, and correcting dimensions and shape of the second bending formed extruded aluminum pipe by pipe expansion forming so that dimensions and shape of the extruded aluminum pipe correspond to design data of the products; and a finish forming step of cutting and grinding the formed extruded aluminum pipe according to predetermined specifications to produce a final product.