Variable radii sheet metal roll forming tool and methods and systems for forming variable radii sheet metal parts with the same

Abstract

Curved sheet metal parts having variable (multiple) radii may be formed using an adjunct roll forming tool in cooperation with a conventional sheet metal rolling machine without the need to adjust spacing between the forming rolls of the machine during conveyance of the sheet metal blank. The roll forming tool preferably is formed as a one piece solid body having leading and trailing edges and defining an upwardly inclined upper surface in a direction between the leading and trailing edges for supporting a sheet metal blank thereon. The upwardly inclined upper surface forms the curved sheet metal part with variable radii when conveyed through forming rolls of the sheet metal roll forming machine without the need to continually adjust the dimensional spacing between the forming rolls during conveyance therethrough.

What is claimed is: 
     
         1 . An adjunct roll forming tool for forming a variable radii curved sheet metal part in a sheet metal roll forming machine, wherein the tool comprises:
 a one piece solid body having leading and trailing edges and defining an upwardly inclined upper surface in a direction between the leading and trailing edges for supporting a sheet metal blank thereon, wherein   the upwardly inclined upper surface forms the curved sheet metal part with variable radii when fed through forming rolls of the sheet metal roll forming machine.   
     
     
         2 . The adjunct roll forming tool according to  claim 1 , wherein the one piece solid body defines a lower planar surface. 
     
     
         3 . The adjunct roll forming tool according to  claim 1 , wherein the upwardly inclined upper surface of the one piece solid body has a upward slope from the leading edge toward the trailing edge thereof. 
     
     
         4 . The adjunct roll forming tool according to  claim 1 , wherein the one piece solid body is comprised of a pliable thermoplastic or thermoset material. 
     
     
         5 . The adjunct roll forming tool according to  claim 4 , wherein the thermoplastic or thermoset material has a Shore A Hardness of between about 80 to about 100. 
     
     
         6 . The adjunct roll forming tool according to  claim 5 , wherein the thermoplastic or thermoset material has a Shore A Hardness of between about 85 to about 95. 
     
     
         7 . The adjunct roll forming tool according to  claim 4 , wherein the thermoplastic material is a thermoplastic polyurethane (TPU). 
     
     
         8 . The adjunct roll forming tool according to  claim 7 , wherein the TPU has a Shore A Hardness of between about 80 to about 100. 
     
     
         9 . The adjunct roll forming tool according to  claim 4 , wherein the one piece body is additively manufactured from the thermoplastic material. 
     
     
         10 . A method of forming a variable radii curved sheet metal part comprising the steps of:
 (a) providing a sheet metal roll forming machine having upper and lower forming rolls defining a fixed dimension roll forming gap therebetween;   (b) providing the adjunct roll forming tool according to  claim 1 ;   (c) positioning a sheet metal blank onto the upwardly inclined upper surface of the adjunct roll forming tool; and   (d) conveying the adjunct roll forming tool and the sheet metal blank positioned on the upwardly inclined upper surface thereof into and through the roll forming gap of the sheet metal roll forming machine while maintaining the fixed dimension of the roll forming gap during conveyance thereof to cause the upper and lower forming rolls to form the variable radii curved sheet metal part from the sheet metal blank.   
     
     
         11 . The method according to  claim 10 , wherein step (d) is practiced by conveying the adjunct roll forming tool in a leading edge-first manner into and through the roll forming gap. 
     
     
         12 . The method according to  claim 11 , which further comprises before step (d) a step of placing the adjunct roll forming tool and the sheet metal blank positioned on the upper surface thereof within a pouch. 
     
     
         13 . The method according to  claim 10 , wherein the one piece solid body of the adjunct roll forming tool defines a lower planar surface. 
     
     
         14 . The method according to  claim 10 , wherein the upwardly inclined upper surface of the one piece solid body has a uniform upward slope from the leading edge toward the trailing edge thereof. 
     
     
         15 . The method according to  claim 10 , wherein the one piece solid body is comprised of a pliable thermoplastic material. 
     
     
         16 . The method according to  claim 15 , wherein the thermoplastic material has a Shore A Hardness of between about 80 to about 100. 
     
     
         17 . The method according to  claim 16 , wherein the thermoplastic material has a Shore A Hardness of between about 85 to about 95. 
     
     
         18 . The method according to  claim 15 , wherein the thermoplastic material is a thermoplastic polyurethane (TPU). 
     
     
         19 . The method according to  claim 18 , wherein the TPU has a Shore A Hardness of between about 85 to about 95. 
     
     
         20 . A sheet metal roll forming system for forming a variable radii curved sheet metal part comprising:
 a sheet metal roll forming machine having upper and lower forming rolls defining a fixed dimension roll forming gap therebetween; and   the adjunct roll forming tool according to  claim 1 .