Method and apparatus for manufacturing a muffler for automotive exhaust systems

Abstract

A method of manufacturing a muffler for an automotive vehicle includes providing an interior subassembly including spaced apart end plates and flow tubes extending generally perpendicular to the end plates. A leading edge of a metal sheet is clamped against the interior subassembly and the sheet is welded proximal the leading edge, to the interior subassembly. The interior subassembly is rotated while maintaining tension on the sheet, thereby causing the sheet to wrap around the interior subassembly as the interior subassembly rotates and the sheet is welded at an intermediate location to the interior subassembly. The rotating of the interior subassembly is repeated and the sheet is welded proximal a trailing edge thereof to one of the interior subassembly and an underlayer of the sheet. The subassembly is then rotated and the sheet is continuous seem welded to the end plates.

1 . A method of manufacturing a muffler for an automotive exhaust, comprising:
 providing an interior subassembly comprising spaced apart end plates, and flow tubes extending generally perpendicularly to the end plates;   clamping a leading edge of a sheet against the interior subassembly;   welding said sheet proximal said leading edge, to said interior subassembly;   rotating the interior subassembly while maintaining tension on the sheet, thereby causing the sheet to wrap around the interior subassembly as the interior subassembly rotates;   welding the sheet at an intermediate location to said interior subassembly;   repeating said rotating the interior subassembly;   welding said sheet proximal a trailing edge thereof to an underlayer of said sheet.   
   
   
       2 . The method according to  claim 1 , comprising repeating said rotating the interior subassembly and welding the sheet at said intermediate location at least once. 
   
   
       3 . The method according to  claim 1 , wherein clamping said leading edge comprises pinching a portion of said sheet proximal said leading edge between a clamp bar and said interior subassembly. 
   
   
       4 . The method according to  claim 1 , comprising forcing a trailing portion of said sheet against said interior subassembly, prior to welding said sheet proximal said leading edge. 
   
   
       5 . The method according to  claim 3 , comprising applying said force against said sheet, on a trailing side of said clamp bar by pinching a trailing portion of said sheet between a roller clamp and said interior subassembly, prior to welding said sheet proximal said leading edge. 
   
   
       6 . The method according to  claim 5 , wherein said welding said sheet proximal said leading edge comprises laser spot welding said sheet to said end plates and to baffles located between said end plates, between said clamp bar and said roller clamp. 
   
   
       7 . The method according to  claim 1 , wherein rotating the interior subassembly includes laterally translating said interior subassembly. 
   
   
       8 . The method according to  claim 1 , comprising continuous seam welding said sheet to each of said end plates. 
   
   
       9 . The method according to  claim 1 , wherein welding said sheet proximal a trailing edge thereof comprises continuous seam welding said sheet proximal said trailing edge. 
   
   
       10 . The method according to  claim 1 , comprising continually applying a force against a trailing portion of said sheet to pinch said trailing portion against said interior subassembly during welding said sheet proximal said leading edge, rotating the interior subassembly, and welding said sheet at said intermediate location. 
   
   
       11 . An apparatus for manufacturing a muffler for an automotive exhaust:
 a housing   a turning device coupled to said housing for holding an interior subassembly of said muffler and for rotating said interior subassembly;   a sheet feeder connected to said housing for feeding a sheet of metal in alignment with and adjacent said interior subassembly;   a clamping apparatus cooperating with said sheet feeder for clamping a leading edge of a sheet against the interior subassembly when said sheet is fed to said subassembly;   a welding apparatus for welding said sheet to said interior subassembly; and   control equipment for controlling rotation of the interior subassembly while the sheet feeder maintains tension on the sheet, thereby causing the sheet to wrap around the interior subassembly as the interior subassembly rotates, and for controlling welding of the sheet.   
   
   
       12 . The apparatus according to  claim 11 , wherein said clamping apparatus comprises a clamp bar for clamping said leading edge of said sheet against said interior subassembly. 
   
   
       13 . The apparatus according to  claim 11 , comprising a second clamping apparatus for forcing a trailing portion of said sheet against the interior subassembly. 
   
   
       14 . The apparatus according to  claim 13 , wherein said second clamping apparatus comprises a roller clamp. 
   
   
       15 . The apparatus according to  claim 11 , wherein said welding apparatus comprises a laser welding apparatus. 
   
   
       16 . The apparatus according to  claim 13 , wherein said welding apparatus comprises a laser welding apparatus and said laser welding apparatus is located for directing a laser weld beam between said clamping apparatus and said second clamping apparatus. 
   
   
       17 . The apparatus according to  claim 11 , wherein said rotation device includes a pair of chucks for clamping said interior subassembly. 
   
   
       18 . The apparatus according to  claim 17 , wherein said mounting mechanism includes a lateral translation mechanism for laterally translating the chucks during rotation thereof, thereby laterally translating the interior subassembly during rotation. 
   
   
       19 . The apparatus according to  claim 11 , comprising a feeder mechanism for feeding said interior subassembly into said mounting mechanism.