Exhaust system and a method of producing the same

Abstract

An exhaust system for use in combination with a combustion engine. The exhaust system includes a silencer having an outer casing that defines an interior and an internal construction within the interior and co-extruded with the outer casing so that the outer casing and the internal construction constitute a one-piece extrusion. The outer casing has a length in a longitudinal direction and a substantially uniform cross-section in a transverse direction. The internal construction has at least one wall that extends the length of the outer casing to define with the outer casing at least two longitudinal chambers within the interior of the outer casing. The wall has a deformed portion and passages through the deformed portion so that the silencer has a path through which gas flows from a first of the two longitudinal chambers and through the passages into the second longitudinal chamber, resulting in noise reduction for the combustion engine.

1 . Exhaust system to be used in combination with a combustion engine, the exhaust system comprising a silencer comprising an outer casing defining an interior and an internal construction within the interior and co-extruded with the outer casing so that the outer casing and the internal construction constitute a one-piece extrusion, the outer casing having a length in a longitudinal direction and a substantially uniform cross-section in a transverse direction, the internal construction comprising at least one wall that extends the length of the outer casing to define with the outer casing at least two longitudinal chambers within the interior of the outer casing the at least one wall having a deformed portion and passages through the deformed portion so that the silencer comprises a path through which gas flows from a first of the at least two longitudinal chambers and through the passages into a second of the at least two longitudinal chambers resulting in noise reduction for the combustion engine.  
   
   
       2 . Exhaust system according to  claim 1 , further comprising at least one baffle separating one of the at least two longitudinal chambers into two longitudinally-aligned chambers.  
   
   
       3 . Exhaust system according to  claim 1 , wherein the outer casing is a multiport extruded tube-element.  
   
   
       4 . Exhaust system according to  claim 1 , wherein the deformed portion is transverse to the longitudinal direction and contacts the outer casing.  
   
   
       5 . Exhaust system according to  claim 1 , wherein the outer casing and the internal construction consist essentially of aluminium or an aluminium alloy.  
   
   
       6 . Exhaust system according to  claim 1 , wherein the outer casing and the at least one wall have complementary deformed end portions that together define an opening into the silencer.  
   
   
       7 . A method of producing an exhaust system, the method comprising: 
 co-extruding an outer casing and an internal construction within an interior of the outer casing so that the outer casing and the internal construction constitute a one-piece extrusion, the outer casing being extruded to have a length in a longitudinal direction and a substantially uniform cross-section in a transverse direction, the internal construction being extruded to comprise at least one wall that extends the length of the outer casing to define with the outer casing at least two longitudinal chambers within the interior of the outer casing; and then    deforming the at least one wall to define a deformed portion and forming passages through the deformed portion so that the silencer comprises a path through which gas flows from a first of the at least two longitudinal chambers and through the passages into a second of the at least two longitudinal chambers, resulting in noise reduction for the combustion engine.    
   
   
       8 . A method according to  claim 7 , further comprising the step of installing at least one baffle to separate one of the at least two longitudinal chambers into two longitudinally-aligned chambers.  
   
   
       9 . A method according to  claim 7 , further comprising the step of shaping the outer casing to fit beneath an undercarriage of an automobile.  
   
   
       10 . A method according to  claim 7 , wherein the deformed portion is deformed so as to be oriented transverse to the longitudinal direction.  
   
   
       11 . A method according to  claim 7 , wherein the deformed portion is deformed so as to contact the outer casing.  
   
   
       12 . A method according to  claim 7 , wherein the outer casing and the internal construction consist essentially of aluminium or an aluminium alloy.  
   
   
       13 . A method according to  claim 7 , further comprising the step of deforming the outer casing and the at least one wall to have complementary deformed end portions that together define an opening into the silencer.  
   
   
       14 . A method according to  claim 7 , wherein the deformed portion is deformed so as to separate one of the at least two longitudinal chambers into two longitudinally-aligned chambers.  
   
   
       15 . Exhaust system according to  claim 1 , wherein the deformed portion separates one of the at least two longitudinal chambers into two longitudinally-aligned chambers.  
   
   
       16 . Exhaust system to be used in combination with a combustion engine, the exhaust system comprising a silencer comprising an outer casing defining an interior and an internal construction within the interior and co-extruded with the outer casing so that the outer casing and the internal construction constitute a one-piece extrusion, the outer casing having a length in a longitudinal direction and a substantially uniform cross-section in a transverse direction, the internal construction comprising at least one wall defining a semicircular opening, the silencer further comprising at least one baffle separating the interior into at least two longitudinally-aligned chambers and a tubular member received in the semicircular opening and interconnecting the two longitudinally-aligned chambers so that the silencer comprises a path through which gas flows from a first of the two longitudinally-aligned chambers and through the tubular member into a second of the two longitudinally-aligned chambers, resulting in noise reduction for the combustion engine.  
   
   
       17 . Exhaust system according to  claim 16 , wherein the outer casing and the internal construction consist essentially of aluminium or an aluminium alloy.