Method of manufacturing a vehicle body component

Abstract

A method of manufacturing a vehicle body component as a flange-integrated tube may include step (a) of forming a pipe material having a closed cross-section with a preset shape, step (b) of cold-forming at least one flange on the pipe material forming a flange formed material, and step (c) of performing hydroforming on the flange formed material having the at least one flange by using liquid pressure.

What is claimed is: 
     
         1 . A method of manufacturing a vehicle body component of a flange-integrated tube, the method comprising:
 step (a) of forming a pipe material having a closed cross-section with a preset shape;   step (b) of cold-forming at least one flange on the pipe material to form a flange formed material; and   step (c) of performing hydroforming on the flange formed material having the at least one flange by using liquid pressure to form a molded product.   
     
     
         2 . The method of  claim 1 , further comprising:
 step (d) of heating the molded product, on which the hydroforming is performed, to a preset temperature in a heating furnace; and   step (e) of rapidly cooling the heated molded product in a water tub.   
     
     
         3 . The method of  claim 2 , wherein trimming and piercing are performed on the molded product. 
     
     
         4 . The method of  claim 2 , wherein a strength of the molded product, which has been subjected to steps (a)-(c), is 60 K or less. 
     
     
         5 . The method of  claim 4 , wherein a strength of the molded product, which has been subjected to steps (a)-(e), is 100 to 150 K. 
     
     
         6 . The method of  claim 1 , wherein, in step (a), pultrusion is performed on a pipe source material subjected to pipe-making forming to have a circular closed cross-section to form the pipe material having a non-circular closed cross-section. 
     
     
         7 . The method of  claim 6 , wherein, in step (a), the pipe material is bent at a preset curvature. 
     
     
         8 . The method of  claim 1 , wherein, in step (a), the pipe material having a non-circular closed cross-section is formed by bending a blank material using a press forming process. 
     
     
         9 . The method of  claim 8 , wherein, in step (a), the pipe material is bent at a preset curvature. 
     
     
         10 . The method of  claim 1 , wherein, in step (b), the pipe material having a non-circular closed cross-section is seated on a press mold and wherein the pipe material is cold-formed by the press mold. 
     
     
         11 . The method of  claim 1 , wherein, in step (c), the flange formed material is expanded and formed by preset hydraulic pressure in a hydroforming mold. 
     
     
         12 . The method of  claim 1 , wherein, trimming and piercing are performed on the molded product.