Exhaust system structure of internal combustion engine

Abstract

An exhaust system structure of an internal combustion engine, includes an exhaust manifold which is configured to be connected to a cylinder of the internal combustion engine, an exhaust pipe which is provided on a downstream side of an exhaust flow from the exhaust manifold, a connection member including a flange portion which connects the exhaust pipe and the exhaust manifold to each other and a boss portion which is provided integrally with the flange portion and is fixed to a portion of an outer circumferential surface of the exhaust pipe, a sensor which is attached to the boss portion and is configured to detect components of the exhaust, and a purification device which is connected to a downstream end of the exhaust pipe and is disposed on a side opposite to the boss portion with respect to the exhaust pipe.

What is claimed is: 
     
         1 . An exhaust system structure of an internal combustion engine, comprising:
 an exhaust manifold which is configured to be connected to a cylinder of the internal combustion engine;   an exhaust pipe which is provided on a downstream side of an exhaust flow from the exhaust manifold;   a connection member including a flange portion which connects the exhaust pipe and the exhaust manifold to each other and a boss portion which is provided integrally with the flange portion and is fixed to a portion of an outer circumferential surface of the exhaust pipe;   a sensor which is attached to the boss portion and is configured to detect components of the exhaust; and   a purification device which is connected to a downstream end of the exhaust pipe and is disposed on a side opposite to the boss portion with respect to the exhaust pipe.   
     
     
         2 . The exhaust system structure of an internal combustion engine according to  claim 1 ,
 wherein the boss portion has a cylindrical shape which has an axis parallel to a direction in which a cylinder head and a cylinder block of the internal combustion engine are arranged in parallel, and   wherein the sensor is attached along the axis of the boss portion.   
     
     
         3 . The exhaust system structure of an internal combustion engine according to  claim 1 ,
 wherein the purification device has a case which extends in the same direction as the direction in which the cylinder head and the cylinder block of the internal combustion engine are arranged in parallel.   
     
     
         4 . The exhaust system structure of an internal combustion engine according to  claim 1 ,
 wherein the purification device is provided to be overhung toward a side of the internal combustion engine from the connection member.   
     
     
         5 . The exhaust system structure of an internal combustion engine according to  claim 1 ,
 wherein the exhaust manifold is built in the cylinder head of the internal combustion engine.   
     
     
         6 . The exhaust system structure of an internal combustion engine according to  claim 1 , further comprising:
 a sensor cover for surrounding the outer circumference of the sensor to block heat,   wherein a portion of the sensor cover is interposed between the sensor and the boss portion of the connection member.