Abstract An exhaust gas recycling system for reducing nitrogen oxides discharged into the atmosphere by internal combustion engines, comprises an exhaust manifold having a baffle therein and a bypass pipe leading from the exhaust manifold to the air intake of the carburetor for returning a portion of the exhaust gases to the inlet of the carburetor in direct dependence upon the vacuum in the inlet to the carburetor, thus automatically recycling a substantial portion of the exhaust gases during those periods of operation when such recycling is desired, i.e., during acceleration and normal operation, when the vacuum at the carburetor inlet is high, and recycling only a minimal quantity of exhaust gases during those periods of operation when such recycling is not desired, i.e., during cranking, idling, deceleration and high load operation, when vacuum in the carburetor air intake is low.
An exhaust gas recycling system, comprising in combination: an internal combustion engine having an exhaust manifold and an inlet manifold; a carburetor on the inlet manifold; an air cleaner housing on the carburetor and having a tubular air intake horn; a first one-piece bypass pipe connected to the exhaust manifold and having one end thereof terminating in the plane of an opening in the exhaust manifold and having a baffle thereon projecting through the opening into the manifold for directing exhaust gases into the bypass pipe; a silencer connected to the other end of the first bypass pipe; and a second one-piece bypass pipe joined at one end thereof to the silencer and extending at its other end into an opening in the side of the air cleaning housing horn, the longitudinal axis of the other end of the second bypass pipe being perpendicular to the longitudinal axis of the horn, whereby air flowing through the horn creates a low pressure in the bypass pipes and draws exhaust gas through the pipes into the carburetor in direct proportion to the amount of air flowing thereinto, said first and second bypass pipes, baffle and silencer comprising the only elements added to the existing manifolds and carburetor.
Claim 2
Dependent Claim
205 words
An exhaust gas recycling system, comprising in combination: an internal combustion engine having an exhaust manifold and an inlet manifold; a carburetor on the inlet manifold; an air cleaner housing on the carburetor and having a tubular air intake horn; a first one-piece bypass pipe connected to the exhaust manifold and having one end thereof terminating in the plane of an opening in the exhaust manifold and having a baffle thereon projecting through the opening into the manifold for directing exhaust gases into the bypass pipe; a silencer connected to the other end of the first bypass pipe; and a second one-piece bypass pipe joined at one end thereof to the silencer and extending at its other end into an opening in the side of the air cleaning housing horn, the longitudinal axis of the other end of the second bypass pipe being perpendicular to the longitudinal axis of the horn, whereby air flowing through the horn creates a low pressure in the bypass pipes and draws exhaust gas through the pipes into the carburetor in direct proportion to the amount of air flowing thereinto, said first and second bypass pipes, baffle and silencer comprising the only elements added to the existing manifolds and carburetor.