US 5,471,835 AGranted

Exhaust system for internal combustion engines

OwnerHarold E. Friedmaninventor

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Abstract

An exhaust control system having a plurality of exhaust manifolds is configured and arranged such that combustion of exhaust gases flowing therethrough is unhibited to the extent that the concentration of major pollutants (CO, HC, NO.sub.x) exiting from the tail pipe and into the environment is substantially reduced. The exhaust system utilizes pairs of primary pipes defining an upstream portion of an exhaust manifold which are coupled to exhaust ports whose respective valves provide fluid flow communication to only one of the primary pipes at any moment in time. A secondary pipe defining an downstream portion of the exhaust manifold is coupled to the outlet of the primary pipes through a connector. One-way valves permit atmospheric air surrounding the exhaust manifold to be drawn into each primary pipe proximate its inlet, and into the secondary pipe proximate the connector.

Claims25

Dependent claims

An exhaust system for an internal combustion engine having a plurality of cylinders, an exhaust port associated with each cylinder, and an exhaust valve associated with each exhaust port, the exhaust system comprising:

a plurality of primary pipes attached to a head for the internal combustion engine and defining an upstream portion of an exhaust manifold, each primary pipe having an inlet and an outlet, wherein the inlets are coupled to the exhaust ports associated with a plurality of cylinders whose respective valves provide fluid flow communication to only one of the primary pipes at any moment in time, and wherein each primary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
a secondary pipe defining a downstream portion of the exhaust manifold and having an inlet coupled to the outlets of the primary pipes through a connector, wherein the secondary pipe inlet has a transverse sectional area at least equivalent to the sum of the transverse sectional areas of the primary pipe outlets, and wherein the secondary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
a fresh air passageway through each primary pipe adjacent to the primary pipe inlet;
and
one-way valve means for permitting atmospheric air surrounding the exhaust manifold to be drawn into each primary pipe through the fresh air passageways.

2 more elements

An exhaust system for an internal combustion engine having a plurality of cylinders and an exhaust port associated with each cylinder, the exhaust system comprising:

a pair of primary pipes defining an upstream portion of an exhaust manifold, each primary pipe having an inlet and an outlet, wherein the inlets are coupled to the exhaust ports associated with two cylinders that are in line and farthest apart from each other in firing order with respect to the cylinders in that line, the transverse sectional area of each primary pipe inlet being greater than the transverse sectional area of the respective exhaust port to which the primary pipe is coupled, and wherein each primary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
a fresh air passageway through each primary pipe adjacent to the primary pipe inlet;
one-way valve means for permitting atmospheric air surrounding the exhaust manifold to be drawn into each primary pipe through the fresh air passageways, the one-way valve means including a conduit connecting the fresh air passageways for the primary pipe pair;
and
a secondary pipe defining a downstream portion of the exhaust manifold and having an inlet coupled to the outlets of the primary pipes through a connector, wherein the secondary pipe inlet has a transverse sectional area at least equivalent to the sum of the transverse sectional areas of the primary pipe outlets, and wherein the secondary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof.

2 more elements

An exhaust system for an internal combustion engine having a plurality of cylinders and an exhaust port associated with each cylinder, the exhaust system comprising:

a pair of primary pipes defining an upstream portion of an exhaust manifold, each primary pipe having an inlet and an outlet, wherein the inlets are coupled to the exhaust ports associated with two cylinders that are in line and farthest apart from each other in firing order with respect to the cylinders in that line, the transverse sectional area of each primary pipe inlet being greater than the transverse sectional area of the respective exhaust port to which the primary pipe is coupled, and wherein each primary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
a secondary pipe defining a downstream portion of the exhaust manifold and having an inlet coupled to the outlets of the primary pipes through a connector, wherein the secondary pipe inlet has a transverse sectional area at least equivalent to the sum of the transverse sectional areas of the primary pipe outlets, and wherein the secondary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
and
means for introducing air through the secondary pipe and into the downstream portion of the exhaust manifold.

1 more element

a plurality of primary pipes attached to a head for the internal combustion engine and defining an upstream portion of an exhaust manifold, each primary pipe having an inlet and an outlet, wherein the inlets are coupled to the exhaust ports associated with a plurality of cylinders whose respective valves provide fluid flow communication to only one of the primary pipes at any moment in time, wherein each primary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
a secondary pipe defining a downstream portion of the exhaust manifold and having an inlet coupled to the outlets of the primary pipes through a connector, wherein the secondary pipe inlet has a transverse sectional area at least equivalent to the sum of the transverse sectional areas of the primary pipe outlets, and wherein the secondary pipe is configured such that any transverse sectional area along the length thereof is at least equivalent to or greater than an upstream transverse sectional area thereof;
and
a reflecting wall extending radially inwardly relative to the inlet of each primary pipe.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 08/259,909Filed 15 Jun 1994 · continuation
Priority: 12 Apr 1991
Granted: 5 Dec 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

F02B 75/22
Multi-cylinder engines: with cylinders in V, fan, or star arrangement
F01N 3/34
Arrangements for supply of additional air: using air conduits or jet air pumps, e.g. near the engine exhaust port
F01N 13/011
Exhaust or silencing apparatus characterised by constructional features: having two or more purifying devices arranged in parallel
F02B 27/04
Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or…:…