Internal combustion engine exhaust device

Abstract

An exhaust device for internal combustion engines, having a main catalyst, an auxiliary catalyst, and an exhaust manifold connecting the input of the main catalyst to the exhaust outlets of the internal combustion engine, so as to feed the exhaust gases from the exhaust outlets to the main catalyst; the exhaust manifold assuming a first operating configuration connecting the input of the main catalyst to the output of the auxiliary catalyst, and the input of the auxiliary catalyst to the internal combustion engine, and a second operating configuration connecting the input of the main catalyst directly to the internal combustion engine and excluding the auxiliary catalyst.

1 ) An exhaust device ( 1 ) for internal combustion engines ( 2 ), comprising a main catalyst ( 3 ), an auxiliary catalyst ( 4 ), and an exhaust manifold ( 5 ) connecting the input of the main catalyst ( 3 ) to the exhaust outlets of a generic internal combustion engine ( 2 ), so as to feed the exhaust gases from said exhaust outlets to the main catalyst ( 3 ); the exhaust device ( 1 ) being characterized in that said exhaust manifold ( 5 ) may selectively assume a first operating configuration connecting the input of the main catalyst ( 3 ) to the output of the auxiliary catalyst ( 4 ), and the input of the auxiliary catalyst ( 4 ) to said internal combustion engine ( 2 ), and a second operating configuration connecting the input of the main catalyst ( 3 ) directly to the internal combustion engine ( 2 ) and excluding the auxiliary catalyst ( 4 ).  
     
     
         2 ) An exhaust device as claimed in  claim 1 , wherein the exhaust manifold ( 5 ) comprises an initial portion ( 5   a ) connected directly to the exhaust outlets of the internal combustion engine ( 2 ); an end portion ( 5   b ) connected directly to the input of the main catalyst ( 3 ); and a first ( 5   c ) and a second ( 5   d ) intermediate portion, each for connecting the end portion ( 5   b ) to the initial portion ( 5   a ); the auxiliary catalyst ( 4 ) being located along said second intermediate portion ( 5   d ); and the exhaust device ( 1 ) also comprising selective connecting means ( 8 ) for connecting, on command, the initial portion ( 5   a ) of the exhaust manifold ( 5 ) directly to said first intermediate portion ( 5   c ) or said second intermediate portion ( 5   d ) respectively.  
     
     
         3 ) An exhaust device as claimed in  claim 2 , wherein said selective connecting means ( 8 ) comprise at least one three-way valve ( 8 ) located at the point at which the initial portion ( 5   a ) and the first ( 5   c ) and second ( 5   d ) intermediate portion of the exhaust manifold ( 5 ) join.  
     
     
         4 ) An exhaust device as claimed in  claim 3 , wherein said at least one three-way valve ( 8 ) has the inlet communicating with the initial portion ( 5   a ) of the exhaust manifold ( 5 ), and the two outlets communicating with the first intermediate portion ( 5   c ) and the second intermediate portion ( 5   d ) of the exhaust manifold ( 5 ) respectively.  
     
     
         5 ) An exhaust device as claimed in  claim 2 , wherein the initial portion ( 5   a ), the first intermediate portion ( 5   c ), and the end portion ( 5   b ) of the exhaust manifold ( 5 ) are defined by a single connecting pipe ( 6 ).  
     
     
         6 ) An exhaust device as claimed in  claim 5 , wherein, before reaching the exhaust outlets of said internal combustion engine ( 2 ), said single connecting pipe ( 6 ) is divided into four smaller-section pipes ( 6 ′), each connected directly to a respective exhaust outlet of the internal combustion engine ( 2 ).  
     
     
         7 ) An exhaust device as claimed in  claim 5 , wherein said connecting pipe ( 6 ) is of such a length, section and shape as to maximize efficiency and performance of the internal combustion engine ( 2 ).