Fluid extraction arrangement for engine air induction system

Abstract

An engine includes an air induction system for providing air to a plurality of cylinders, an exhaust system for conveying exhaust gas from the cylinders, and a secondary air injection (SAI) system for extracting air from the induction system and injecting the air into the exhaust system to promote exhaust gas oxidation and to heat a catalytic converter. The SAI system extracts air from the induction system through a plurality of holes to evenly distribute the effects of the extraction, thereby reducing velocity gradients and turbulence levels around the mass air flow sensor inside the induction system.

1 . An internal combustion engine comprising: 
 an air induction system including an intake manifold and a conduit defining an air passageway in fluid communication with the intake manifold, said conduit defining a plurality of holes;    an exhaust system including an exhaust manifold configured to convey exhaust gas; and    a secondary air injection system being configured to convey air from said conduit through said plurality of holes to said exhaust system.    
     
     
         2 . The internal combustion engine of  claim 1 , wherein said plurality of holes are evenly spaced from one another along the periphery of said conduit.  
     
     
         3 . The internal combustion engine of  claim 1 , further comprising a coupling concentrically surrounding said conduit and cooperating with said conduit to define a chamber in fluid communication with said secondary air injection system and in fluid communication with said passageway via said plurality of holes.  
     
     
         4 . The internal combustion engine of  claim 3 , wherein said conduit is generally circular in cross section; and wherein said chamber is generally annularly shaped.  
     
     
         5 . The internal combustion engine of  claim 4 , wherein said plurality of holes includes at least four holes.  
     
     
         6 . An internal combustion engine comprising: 
 an air induction system including an intake manifold and a conduit; said conduit having an inner surface and an outer surface, said inner surface defining an air passageway in fluid communication with the manifold; said conduit defining a plurality of holes extending from the passageway to the outer surface;    an exhaust system including an exhaust manifold configured to convey exhaust gas; and    a secondary air injection system being configured to convey air from said conduit to said exhaust system; said secondary air injection system including a coupling surrounding a portion of said conduit and cooperating with said outer surface of said conduit to define a chamber in fluid communication with said holes; said chamber being in fluid communication with said secondary air injection system.    
     
     
         7 . The internal combustion engine of  claim 6 , wherein said conduit has a circular cross section and wherein said chamber is generally annular.  
     
     
         8 . The internal combustion engine of  claim 6 , wherein said plurality of holes are evenly spaced circumferentially.  
     
     
         9 . An air intake system for an internal combustion engine with a secondary air injection system, the air intake system comprising: 
 an air filter;    an intake manifold;    a conduit defining a passageway that provides fluid communication between the air filter and the intake manifold, said conduit defining a plurality of holes being evenly spaced along the circumference of the conduit; and    a coupling operatively connectable to the secondary air injection system and cooperating with the conduit to define a chamber in fluid communication with the passageway via the plurality of holes.