Exhaust device comprising a cylinder head with a thermally decoupled integrated exhaust manifold

Abstract

An exhaust device for a motor vehicle multi-cylinder internal combustion engine including a cylinder head of the engine in which there are exhaust ducts, a first end of each of which is connected to a combustion chamber of the engine and a second end of which opens into a cavity or plenum of an exhausted manifold integrated into the cylinder head of which an outlet duct is externally connected to a device for removing contamination from the exhaust gases of an exhaust line of the vehicle. The cavity or plenum of the manifold is formed in an element attached inside the cylinder head, and the element is thermally decoupled from the cylinder head using a thermal decoupling mechanism.

1 - 7 . (canceled) 
   
   
       8 . An exhaust device for a multicylinder internal combustion engine of a motor vehicle comprising:
 a cylinder head of the engine in which are arranged exhaust ducts of which a first end of each is connected to a combustion chamber of the engine and a second end opens into a cavity or plenum of an exhaust manifold incorporated into the cylinder head of which an outlet duct is connected externally to a device for depolluting exhaust gases of an exhaust line of the vehicle, of a type in which a cavity or plenum of the manifold is formed in an element fitted to an inside of the cylinder head and the fitted element is thermally decoupled from the cylinder head by thermal decoupling means,   wherein the second ends of the exhaust ducts open into a receiving bore formed in the cylinder head that receives a tubular insert fitted to the inside of the cylinder head to form the fitted element, which comprises orifices for communication with the second ends of the exhaust ducts, and which comprises the outlet duct opening to the outside of the cylinder head.   
   
   
       9 . The exhaust device as claimed in  claim 8 , wherein the tubular insert is made of stainless steel. 
   
   
       10 . The exhaust device as claimed in  claim 8 , wherein the tubular insert is mounted without clearance in the receiving bore of the cylinder head. 
   
   
       11 . The exhaust device as claimed in  claim 10 , wherein the thermal decoupling means are arranged in the cylinder head around the tubular insert and at least between two consecutive exhaust ducts. 
   
   
       12 . The exhaust device as claimed in  claim 11 , wherein the thermal decoupling means comprises at least one cavity formed in the material of the cylinder head around the receiving bore and that opens into the bore. 
   
   
       13 . The exhaust device as claimed in  claim 12 , further comprising a cavity arranged around the receiving bore between each pair of consecutive exhaust ducts, and a cavity arranged around the receiving bore between an end exhaust duct and an end outer face of the cylinder head. 
   
   
       14 . The exhaust device as claimed in  claim 12 , wherein each cavity is produced when the cylinder head is molded. 
   
   
       15 . The exhaust device as claimed in  claim 9 , wherein the tubular insert is mounted without clearance in the receiving bore of the cylinder head. 
   
   
       16 . The exhaust device as claimed in  claim 15 , wherein the thermal decoupling means are arranged in the cylinder head around the tubular insert and at least between two consecutive exhaust ducts. 
   
   
       17 . The exhaust device as claimed in  claim 16 , wherein the thermal decoupling means comprises at least one cavity formed in the material of the cylinder head around the receiving bore and that opens into the bore. 
   
   
       18 . The exhaust device as claimed in  claim 17 , further comprising a cavity arranged around the receiving bore between each pair of consecutive exhaust ducts, and a cavity arranged around the receiving bore between an end exhaust duct and an end outer face of the cylinder head. 
   
   
       19 . The exhaust device as claimed in  claim 17 , wherein each cavity is produced when the cylinder head is molded.