Exhaust system for a combustion engine

Abstract

An exhaust system for a combustion engine having a plurality of cylinders, a cylinder head and an engine block is provided. The exhaust system comprises an exhaust manifold, which is integrated in the cylinder head, flow channels, and an exhaust pipe, which is connected to a head flange of the cylinder head. The flow channels each extend from one of the cylinders to a head flange. At least two of the flow channels, which are connected to cylinders that are not ignited in succession, are united within the cylinder head and form a common flow channel. At least one further flow channel, which is connected with a cylinder ignited in succession, is routed separately as far as to the head flange. The common flow channel is united with the further flow channel only in the exhaust pipe.

What is claimed is: 
     
         1 . An exhaust system for a combustion engine having a plurality of cylinders, a cylinder head and an engine block, the exhaust system comprising:
 an exhaust manifold integrated in the cylinder head;   a plurality of first flow channels, which each extend from one of the cylinders to a head flange, at least two of the plurality of first flow channels are connected to cylinders which are not ignited in succession in a firing order, and are united within the cylinder head to form a common flow channel;   a second flow channel, which is connected to a cylinder that is ignited in succession in the firing order and is conducted separately as far as to the head flange; and   an exhaust pipe that is connected to the head flange,   wherein the common flow channel is united with the second flow channel only in the exhaust pipe.   
     
     
         2 . The exhaust system according to  claim 1 , wherein the second flow channel is connected to the common flow channel downstream of the head flange. 
     
     
         3 . The exhaust system according to  claim 1 , wherein a third flow channel of a cylinder, which follows one of the two cylinders in succession in the firing order is connected to the common flow channel downstream of the cylinder head. 
     
     
         4 . The exhaust system according to  claim 1 , wherein the exhaust pipe comprises at least two separate flow channels. 
     
     
         5 . The exhaust system according to  claim 1 , wherein the exhaust pipe comprises a separating wall at an inlet end, wherein two separate inlet flow channels are formed. 
     
     
         6 . The exhaust system according to  claim 5 , wherein the exhaust pipe comprises at least two inlet flow channels and a single common exhaust flow channel, which is connected to the inlet flow channels. 
     
     
         7 . The exhaust system according to  claim 6 , wherein the exhaust pipe comprises an inlet flange having at least two inlet openings, an exhaust flange with an exhaust opening, and inlet flow channels, wherein the inlet flange is connected to the head flange of the integrated exhaust manifold, and the inlet flow channels each extend from one of the inlet openings as far as to the exhaust opening, wherein the inlet flow channels from the inlet openings are separated from each other for a predetermined distance in the direction of the exhaust opening and after this distance are united and form a combined flow channel. 
     
     
         8 . The exhaust system according to  claim 7 , wherein one of the inlet openings is connected to the common flow channel and one of the inlet openings to the second flow channel. 
     
     
         9 . The exhaust system according to  claim 1 , wherein two of the plurality of first flow channels of two further cylinders, which do not follow in succession in the firing order, are united within the cylinder head and form a second common flow channel. 
     
     
         10 . The exhaust system according to  claim 9 , wherein the second common flow channel is connected to the first common flow channel after a predetermined distance downstream of the head flange within the exhaust pipe. 
     
     
         11 . A combustion engine having an engine block, the combustion engine comprising:
 a plurality of cylinders having a cylinder head; and   an exhaust system, including:
 an exhaust manifold integrated in the cylinder head; 
 a plurality of first flow channels, which each extend from one of the cylinders to a head flange, with two of the plurality of first flow channels connected to cylinders which are not ignited in succession in a firing order and are united within the cylinder head to form a first common flow channel, and two of the plurality of first flow channels of two further cylinders, which do not follow in succession in the firing order, are united within the cylinder head and form a second common flow channel; 
 a second flow channel, which is connected to a cylinder that is ignited in succession in the firing order and is conducted separately as far as to the head flange; and 
 an exhaust pipe that is connected to the head flange, 
 wherein the first common flow channel is united with the second flow channel only in the exhaust pipe. 
   
     
     
         12 . The combustion engine according to  claim 11 , wherein the second flow channel is connected to the first common flow channel downstream of the head flange. 
     
     
         13 . The combustion engine according to  claim 11 , wherein the exhaust pipe comprises at least two separate flow channels. 
     
     
         14 . The combustion engine according to  claim 11 , wherein the exhaust pipe comprises a separating wall at an inlet end, wherein two separate inlet flow channels are formed. 
     
     
         15 . The combustion engine according to  claim 14 , wherein the exhaust pipe comprises at least two inlet flow channels and a single common exhaust flow channel, which is connected to the inlet flow channels. 
     
     
         16 . The exhaust system according to  claim 15 , wherein the exhaust pipe comprises an inlet flange having at least two inlet openings, an exhaust flange with an exhaust opening, and inlet flow channels, wherein the inlet flange is connected to the head flange of the integrated exhaust manifold, and the inlet flow channels each extend from one of the inlet openings as far as to the exhaust opening, wherein the inlet flow channels from the inlet openings are separated from each other for a predetermined distance in the direction of the exhaust opening and after this distance are united and form a combined flow channel. 
     
     
         17 . The exhaust system according to  claim 16 , wherein one of the inlet openings is connected to the first common flow channel and one of the inlet openings to the second flow channel. 
     
     
         18 . A vehicle having a combustion engine, the vehicle comprising:
 a combustion engine including a plurality of cylinders each having a cylinder head; and   an exhaust system, including:
 an exhaust manifold integrated in the cylinder head; 
 a plurality of first flow channels, which each extend from one of the cylinders to a head flange, with two of the plurality of first flow channels connected to cylinders which are not ignited in succession in a firing order and are united within the cylinder head to form a first common flow channel, and two of the plurality of first flow channels of two further cylinders, which do not follow in succession in the firing order, are united within the cylinder head and form a second common flow channel; 
 a second flow channel, which is connected to a cylinder that is ignited in succession in the firing order and is conducted separately as far as to the head flange; and 
 an exhaust pipe that is connected to the head flange, 
 wherein the first common flow channel is united with the second flow channel only in the exhaust pipe, and the second flow channel is connected to the first common flow channel downstream of the head flange. 
   
     
     
         19 . The combustion engine according to  claim 18 , wherein the exhaust pipe comprises at least two separate flow channels.