Method of spin forming a catalytic converter

Abstract

A method is provided of manufacturing a catalytic converter using a spin forming operation. At least one catalytic element is inserted in a tubular member. At least one spin forming wheel is provided for forming the tubular member. A force is applied to a first end section of the tubular member by the at least one spin forming wheel for forming a first conical-shaped end. A force is applied to a second end section of the tubular member by the at least one spin forming wheel for forming a second conical-shaped end. A force is applied by the at least one spin forming wheel to the outer surface of the tubular member between the first conical-shaped end and the second conical-shaped end for forming an indentation therebetween and preventing axial movement of the at least one catalytic element.

1 . A method of manufacturing a catalytic converter using a spin forming operation, said method comprising the steps of:
 providing a metallic tubular member having a substantially cylindrical outer surface and an inner surface;   inserting at least one catalytic element in said tubular member;   loading an end of said metallic tubular member into a spin forming machine;   providing at least one spin forming wheel for forming said tubular member;   applying a force to a first end region of said tubular member by said at least one spin forming wheel for forming a first conical-shaped end;   applying a force to a second end region of said tubular member by said at least one spin forming wheel for forming a second conical-shaped end; and   applying a force by said at least one spin forming wheel to said outer surface of said tubular member between said first conical-shaped end and said second conical-shaped end for forming an indentation therebetween and preventing axial movement of said at least one catalytic element.   
     
     
         2 . The method of  claim 1  further comprising the steps of:
 applying a force by said at least one spin forming wheel to said outer surface of said tubular member that is axially aligned with said first catalytic element for securing said at least one catalytic element.   
     
     
         3 . A method of manufacturing a catalytic converter using a spin forming operation, said method comprising the steps of:
 providing a metallic tubular member having a substantially cylindrical outer surface and an inner surface;   inserting at least one catalytic element in said tubular member;   loading an end of said metallic tubular member into a spin forming machine;   positioning at least two spin forming wheels equally spaced around the tubular member;   applying a force to said outer surface of said tubular member by said at least two spin forming wheels for securing said at least one catalytic element within said tubular member; and   applying a force by said at least two spin forming wheels to said outer surface of said tubular member at a first end region and at a second end region for forming a first conical-shaped end and a second conical-shaped end.   
     
     
         4 . The method of  claim 3  wherein said step of applying a force to said outer surface includes applying an equally distributed force by said at least two spin forming wheels to said outer surface that is axially aligned with said at least one catalytic element for securing said at least one catalytic element within said tubular member. 
     
     
         5 . The method of  claim 4  wherein said step of applying a force to said outer surface further includes applying an equally distributed force by said at least two spin forming wheels to said outer surface of said tubular member between said first conical-shaped end and said second conical-shaped end for forming an indentation therebetween and preventing axial movement of said at least one catalytic element. 
     
     
         6 . The method of  claim 5  wherein said first conical shaped-end, said second conical-shaped end, said midsection, and said outer surface co-axially aligned with said catalytic elements are formed by a continuous spin-forming operation. 
     
     
         7 . The method of  claim 6  wherein said first conical shaped-end, said second conical-shaped end, said midsection, and said outer surface co-axially aligned with said catalytic elements are formed by discrete spin forming operations. 
     
     
         8 . The method of  claim 3  wherein said force applied to said first end region and said second end region to form said first conical-shaped end and said second conical-shaped end is substantially equally distributed by said at least two spin forming wheels. 
     
     
         9 . The method of  claim 3  wherein only said tubular member is rotated during said spin forming operation. 
     
     
         10 . The method of  claim 3  wherein only said at least two forming wheels are rotated during said spin forming operation. 
     
     
         11 . The method of  claim 3  wherein said tubular member is rotated during said spin forming operation and said at least two forming wheels are rotated about said tubular member during said spin forming operation. 
     
     
         12 . A method of manufacturing a plurality of catalytic converters using a spin forming operation, said method comprising the steps of:
 (a) providing a metallic tubular member having a substantially cylindrical outer surface and an inner surface;   (b) separating said tubular member into individual tubular sections;   (c) inserting at least one catalytic element in a respective tubular section;   (d) mounting an end of said respective tubular section to a spin forming machine;   (e) positioning at least two spin forming wheels equally spaced around the respective tubular section;   (f) applying a force to said outer surface axially aligned with said at least one catalytic element by said at least two spin forming wheels for securing said first catalytic element and said second catalytic element within said respective tubular section;   (g) applying a force to said outer surface of a first end and said outer surface of said second end of said respective tubular section by said at least two spin forming wheels for forming a first conical-shaped end and a second conical-shaped end;   (h) applying a force to said outer surface region of said respective tubular section between said first conical-shaped end and said second conical-shaped end for forming an indentation therebetween; and   (i) repeating steps (c)-(h) for each respective tubular section.   
     
     
         13 . The method of  claim 12  wherein a respective internal cone is inserted in each end of said tubular section prior to step (d). 
     
     
         14 . The method of  claim 12  wherein during step (g) after said first conical-shaped end is formed, said respective tubular section is un-mounted from said spin forming machine and mounted at an opposite end of said respective tubular section for forming said second conical-shaped end. 
     
     
         15 . The method of  claim 12  wherein said first conical shaped-end, said second conical-shaped end, said indentation, and said respective tubular section axially aligned with said catalytic elements are formed by a continuous spin-forming operation. 
     
     
         16 . The method of  claim 12  wherein said first conical shaped-end, said second conical-shaped end, said indentation, and said respective tubular section axially aligned with said catalytic elements are formed by discrete spin forming operations. 
     
     
         17 . The method of  claim 12  further comprising the step of removing a desired length of material from at least one of said conical-shaped ends. 
     
     
         18 . The method of  claims 12  wherein said forces applied to said tubular section to form said first conical-shaped end, said second conical-shaped end, said indentation, and said respective tubular section axially aligned with said catalytic elements are equally distributed by said at least two spin forming wheels. 
     
     
         19 . The method of  claim 12  wherein said metallic tubular member is formed from wrapped sheet metal strip having a welded seam. 
     
     
         20 . The method of  claim 12  wherein said metallic tubular member is formed from an extrusion process. 
     
     
         21 . A method of manufacturing a plurality of catalytic converters using a spin forming operation, said method comprising the steps of:
 (a) inserting a plurality of catalytic elements in a metallic tubular member;   (b) forming a plurality of axially spaced neck portions by at least two spin forming wheels, said plurality of neck portions each having a diameter less than an initial diameter of said metallic tubular member; and   (c) cutting substantially a midpoint of said neck portions.   
     
     
         22 . The method of  claim 21  wherein during step (b) a force is applied by said at least two spin forming wheels to an outer surface region of said tubular member that is axially aligned with said plurality of catalytic elements for securing said plurality of catalytic elements within said tubular member. 
     
     
         23 . The method of  claim 22  wherein during step (b) a force is applied said at least two forming wheels to said outer surface of said respective tubular region between said plurality of axially spaced neck portions for forming respective indentations therebetween for preventing axial movement of said catalytic elements. 
     
     
         24 - 28 . (canceled)