Method of incremental cold forming an angled corner in a continuous sheet of advanced high strength metal

Abstract

An outer bend radius is cold formed in an outer position within a final arc of the angled corner with an outer bend radius male die member. A central bend radius is cold formed in a central position spaced from the outer position and within the final arc of the angled corner with a central bend radius male die member. An inner bend radius is cold formed in an inner position that is spaced from the outer and central positions and the inner position is within a final arc of the angled corner with an inner bend radius male die member. The angled corner is transferred between each of the bend radii male die members using a continuous advanced high strength metal sheet in which the angled corner is formed.

1 . A method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet, the method comprising:
 cold forming an outer bend radius in an outer position within a final arc of the angled corner of the continuous advanced high strength metal sheet with an outer bend radius male die member;   cold forming a central bend radius in a central position spaced from the outer position and within the final arc of the angled corner of the continuous advanced high strength metal sheet with a central bend radius male die member;   cold forming an inner bend radius in an inner position spaced from the outer position and the central position and within a final arc of the angled corner of the continuous advanced high strength metal sheet with an inner bend radius male die member;   utilizing a progressive die forming apparatus to perform each of the cold forming and transferring operations; and   transferring the angled corner between each of the bend radius male die members by manipulating the continuous advanced high strength metal sheet;   wherein the cold forming the outer bend radius occurs before the cold forming the central bend radius, which cold forming the central bend radius occurs before the cold forming the inner bend radius.   
     
     
         2 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , further comprising cold forming at least one additional central bend radius within the final arc of the angled corner, each additional bend radius being located in a corresponding additional central bend radius position that is spaced from all other bend radii positions. 
     
     
         3 . (canceled) 
     
     
         4 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , further comprising cold forming at least one additional central bend radius within the final arc of the angled corner, each additional bend radius being located in a corresponding additional central bend radius position that is spaced from all other bend radii positions, wherein the cold forming the outer bend radius occurs before the cold forming the central bend radius, which cold forming the central bend radius occurs before the cold forming the additional central bend radius, which cold forming the additional central bend radius occurs before the cold forming the inner bend radius. 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , wherein none of the outer, central or inner bend radii cold forming operations result in forming an initial arched surface extending from the angled corner that is subsequently flattened. 
     
     
         8 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , wherein none of the outer, central or inner bend radii are subsequently flattened to account for springback. 
     
     
         9 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , wherein the angled corner defines an angle that is at least 60 degrees. 
     
     
         10 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , wherein the metal sheet is an ultra-high strength steel. 
     
     
         11 . The method of incremental cold forming an angled corner in a continuous advanced high strength metal sheet of  claim 1 , wherein the metal sheet is one of a 7000 series aluminum alloy and a magnesium alloy.