Draw-form for exhaust components and method of manufacture

Abstract

Exhaust tubes comprise tubular structures having draw-forms formed therein so as to provide a flat portion where a HEGO boss (Heated Exhaust Gas Oxygen) can be welded for placement of the HEGO sensor. In such circumstances, it is, therefore, useful that such draw-forms have substantially flat portions. The present invention provides a tubular member having an outer wall, and a draw-form formed in the outer wall. The draw-form comprises a substantially flat bottom portion, a plurality of walls extending upwardly from the bottom portion and attached to the outer wall, and wherein the walls are configured in a polygonal orientation.

1 . A tubular member comprising: 
 an outer wall; and    a draw-form formed in said outer wall, said draw-form comprising: 
 a substantially flat bottom portion;  
 a plurality of walls extending upwardly from said bottom portion and attached to said outer wall; and  
   wherein said walls are configured in a polygonal orientation.    
   
   
       2 . The tubular member of  claim 1 , wherein said draw-form further includes an aperture extending through said bottom portion.  
   
   
       3 . The tubular member of  claim 2 , wherein said walls have substantially rounded corners.  
   
   
       4 . The tubular member of  claim 3 , wherein said walls are integrally formed with said bottom potion.  
   
   
       5 . The tubular member of  claim 4 , wherein said polygonal configuration is a rectangular configuration.  
   
   
       6 . The tubular member of  claim 4 , wherein said polygonal configuration is a square configuration.  
   
   
       7 . The tubular member of  claim 3 , wherein polygonal configuration of said walls substantially prevent deformation of said draw-form during subsequent forming operations.  
   
   
       8 . The tubular member of  claim 7 , wherein said bottom portion remains substantially free from deformation during subsequent forming operations.  
   
   
       9 . The tubular member of  claim 7 , wherein said subsequent forming operations includes swaging said tubular member.  
   
   
       10 . The tubular member of  claim 1 , wherein said walls are substantially perpendicular to said bottom portion.  
   
   
       11 . An exhaust tube comprising: 
 a tube having an outer wall defining an interior exhaust passage;    a draw-form formed in said outer wall, said draw-form comprising: 
 a substantially flat bottom portion;  
 a plurality of walls extending upwardly from said bottom portion and integrally attached to said outer wall; and  
 wherein said walls are configured in a polygonal orientation to substantially prevent deformation of said draw-form during subsequent forming operations.  
   
   
   
       12 . The exhaust tube of  claim 11 , further including an aperture extending through said bottom portion.  
   
   
       13 . The exhaust tube of  claim 12 , wherein said walls have substantially rounded corners.  
   
   
       14 . The exhaust tube of  claim 13 , wherein said polygonal configuration is a rectangular configuration.  
   
   
       15 . The exhaust tube of  claim 13 , wherein said polygonal configuration is a square configuration.  
   
   
       16 . The exhaust tube of  claim 13 , wherein said rounded corners act as strengthening ridges.  
   
   
       17 . The exhaust tube of  claim 16 , wherein said bottom portion remains substantially free from deformation during subsequent forming operations.  
   
   
       18 . The exhaust tube of  claim 17 , further comprising a heated exhaust gas oxygen boss inserted into said draw-form, wherein said heated exhaust gas oxygen boss includes projections for assisting in attaching said heated exhaust gas oxygen boss to said draw-form.  
   
   
       19 . The exhaust tube of  claim 18 , further comprising a heated exhaust gas oxygen sensor inserted into said heated exhaust gas oxygen boss.  
   
   
       20 . The exhaust tube of  claim 19 , wherein said subsequent forming operations includes swaging said tubular member.  
   
   
       21 . A method of manufacturing a draw-form, said method comprising: 
 placing a tubular member having an outer wall in a fixture;    forming a substantially flat bottom portion in said outer wall of said tube;    forming a plurality of walls extending upwardly from said bottom portion and attached to said outer wall, wherein said walls are configured in a polygonal orientation to maintain said bottom portion substantially free from deformation during subsequent forming operations.    
   
   
       22 . The method of  claim 21 , further comprising swaging said tube wherein deformation of said draw-form is substantially prevented.  
   
   
       23 . The method of  claim 22 , wherein said walls have rounded corners that act as strengthening ridges.  
   
   
       24 . The method of  claim 23 , wherein said polygonal configuration comprises a rectangular configuration.  
   
   
       25 . The method of  claim 23 , wherein said polygonal configuration comprises a square configuration.  
   
   
       26 . The method of  claim 25 , wherein forming said substantially flat bottom portion is formed by a stamp.  
   
   
       27 . The method of  claim 26 , wherein said substantially flat bottom portion, said walls, and said aperture are formed by a single operation.