Southwest Research Institute

Raphael Gukelberger

Jess Witman Gingrich

Garrett L Anderson

Steven Almaraz

Bradley Denton

Terrence F Alger, Iii

Christopher James Chadwell

Gordon J J Bartley

Forest C Gibson

Jacob R Zuehl

A method of improving fuel delivery in an engine having one or more cylinders that are over-fueled related to other cylinders, such as a D-EGR engine. The fueling system uses a mechanical fuel pump, which is cam-driven. The cam has lobes corresponding to the desired displacement for each cylinder. The lobe corresponding to the over-fueled cylinder is shaped differently, such that the filling stroke of the pump is increased.

Internal combustion engine having dedicated EGR cylinder(s) and improved fuel pump system

An engine and a method of operating the engine wherein fuel, intake air, and recirculated exhaust gas provides a first mixture, which is inducted into a first combustion cylinder. The first mixture is combusted in the combustion cylinder to generate a first exhaust gas that applies pressure to a piston within the combustion cylinder, reciprocating the piston and rotating a primary crankshaft coupled to the piston. Fuel and intake air, which provides a second mixture, are inducted into a rotary combustion chamber. The second mixture is combusted in the rotary combustion chamber, wherein the combustion generates a recirculated exhaust gas that applies pressure to the rotor and rotates the rotor and a secondary crankshaft coupled to the rotor. The secondary crankshaft is coupled to the primary crankshaft by a gear mechanism. The recirculated exhaust gas is exhausted into an exhaust gas recirculation loop and recirculated.

Internal combustion, dedicated exhaust gas recirculation engine

A method of implementing start-stop in an internal combustion engine, the engine having exhaust gas recirculation (EGR) from at least one dedicated EGR (D-EGR) cylinder. For stopping the engine, the camshaft is locked, and a hydraulic cam phaser is used to cushion the engine inertia. The engine is stopped such that one of the D-EGR cylinders is in top-dead center position. For starting the engine, that D-EGR cylinder is fuel-injected, and exhaust bleed-off performed if necessary.

Internal combustion engine having dedicated EGR cylinder(s) and start-stop operation

A method of operating a split intake D-EGR (dedicated exhaust gas recirculation) engine having at least one D-EGR cylinder and a number of non-EGR cylinders. If the engine is in a low load operating condition, either of two cylinder deactivation modes may be performed. In first cylinder deactivation mode, the D-EGR cylinder(s) are deactivated by disabling fuel delivery to the D-EGR cylinder(s), closing a D-EGR throttle, closing a D-EGR valve, and operating a three-way valve on the main exhaust line such that no exhaust from the D-EGR cylinder(s) is exhausted. In a second cylinder deactivation mode, the non-EGR cylinders are deactivated by disabling fuel delivery to the non-EGR cylinders, opening the D-EGR throttle, closing the D-EGR valve, and operating the three-way valve such that no exhaust from the main cylinders is exhausted.

Internal combustion engine having dedicated EGR cylinder(s) with split intake and cylinder deactivation at low loads

A dedicated exhaust gas recirculation configuration that provides reduced exhaust gas recirculation (EGR) backflow and reduced fresh air backflow. One-way valves are positioned in the EGR loop to reduce or avoid fresh-air backflow into the dedicated exhaust gas recirculating cylinder and/or positioned in the engine intake passage to reduce or avoid dedicated cylinder exhaust gas backflow into the intake passage.

Dedicated exhaust gas recirculation configuration for reduced EGR and fresh air backflow

A method of controlling fuel injection to the cylinders of an internal combustion engine, the engine having exhaust gas recirculation (EGR) from at least one dedicated EGR (D-EGR) cylinder, with the other cylinders being main cylinders. The D-EGR cylinder(s) are run at a richer equivalence ratio than the main cylinders, with the goal of providing increased H2 and CO in the recirculated exhaust. The start of fuel injection to the D-EGR cylinder(s) is delayed as compared to the start of fuel injection to the main cylinders.

Internal combustion engine having dedicated EGR cylinder(s) with delayed fuel injection

A four stroke internal combustion engine with dedicated exhaust gas recirculation and method of operating such engine, wherein the engine comprises a plurality of combustion cylinders including main cylinders and a dedicated exhaust gas recirculation cylinder, wherein each cylinder includes a piston; a crankshaft, which is rotatable in a direction, and defines a main crankshaft axis, and includes a plurality of crankpins. Each of the crankpins is coupled to at least one of the pistons. The crankpins affixed to the pistons of the main cylinders are spaced at an interval around the main crankshaft axis. The crankpin affixed to the piston of the dedicated exhaust gas recirculation cylinder is spaced at an offset of 5 to 50 degrees from the interval in either direction relative to the direction of crankshaft rotation.

Crank pin offset in dedicated exhaust gas engines

A method of operating an dedicated exhaust gas recirculation engine including a water gas shift catalyst by supplying ambient air and fuel to a dedicated cylinder at a first fuel to air equivalence ratio in the range of greater than 1.0 to 1.6 for a first number of engine cycles and, for a second number of engine cycles, supplying ambient air and fuel to the dedicated cylinder at a second fuel to air equivalence ratio in the range of 0.7 to less than 1.0. During the second number of cycles, spark timing of the dedicated cylinder is adjusted and a time delay when exhaust recirculated from the dedicated cylinder will be inducted into the cylinders is determined. At the end of the time delay, a second spark timing of the main cylinder is adjusted and the amount of fuel supplied to the main cylinders is increased.

Dedicated exhaust gas recirculation engine fueling control

A method of controlling fuel injection to the cylinders of an internal combustion engine, the engine having exhaust gas recirculation (EGR) from at least one dedicated EGR (D-EGR) cylinder, with the other cylinders being main cylinders. The D-EGR cylinder is run at a richer equivalence ratio than the main cylinders, with the goal of providing increased H2 and CO in the recirculated exhaust. The rich limit of the D-EGR cylinder is maximized by dividing the fuel injection into multiple fuel injection events, with each fuel injection event occurring during the intake valve lift period of the engine cycle.

Internal combustion engine having dedicated EGR cylinder(s) with split fuel injection timing

A method of using exhaust gas recirculation (EGR) in an internal combustion engine. At least two of the cylinders are 'dual exhaust-ported cylinders' having two exhaust ports. For each of these cylinders, one of the exhaust ports is connected to the EGR loop and the other of the exhaust ports is connected to the main exhaust line. These cylinders are controlled such that one exhaust port is open and the other exhaust port is closed during each engine cycle, and are operated, on a cycle-by-cycle basis so that all of the exhaust produced by a cylinder may be delivered to the EGR loop at any cycle. The number of cylinders operating as EGR cylinders per engine cycle is in response to a desired EGR rate.

EGR rate control for internal combustion engine with dual exhaust-ported cylinders

A method of controlling the amount of fuel delivered to an engine having at least one dedicated EGR cylinder. The method is typically performed on an engine cycle-by-cycle basis. A fueling control unit receives, from the engine's main control unit, fueling requirement data representing a current fueling requirement suitable for the main cylinders. The fueling control unit then calculates a current amount of fuel to be delivered to the dedicated EGR cylinder as a function of the number of dedicated EGR cylinders, the number of main cylinders, the current equivalence ratio for the dedicated EGR cylinder, and the fueling requirement data. With the amounts of fuel for both the dedicated EGR cylinder and the main cylinders now having been determined, the fueling control unit generates appropriate control signals to the cylinder fuel delivery mechanisms.

Engine fuel control for internal combustion engine having dedicated EGR

A dual EGR loop exhaust gas recirculation (EGR) system for an internal combustion engine. The engine has both a dedicated EGR loop and a low pressure EGR loop. This means that one or more engine cylinders is operable as a dedicated EGR cylinder, such that all of its exhaust is recirculated via the dedicated EGR loop. The other cylinders are operable as main cylinders having two intake ports, such that each main cylinder may receive a mixture of fresh air and dedicated EGR through one intake port and a mixture of fresh air and low pressure EGR through the other intake port. A control unit controls this dual loop EGR system to either provide EGR only from the dedicated EGR loop or to also provide additional EGR from the low pressure EGR loop.

Internal combustion engine having dual EGR loops (dedicated EGR loop and low pressure EGR loop) and dual cylinder intake ports

A method using exhaust gas recirculation (EGR) in an internal combustion engine. The engine has at least one 'dedicated EGR cylinder', whose entire exhaust is recirculated back to all the engine cylinders. The dedicated EGR cylinder is operated at a rich air-fuel ratio, and the other cylinders are operated stoichiometrically so that a conventional three way catalyst may be used to treat the exhaust. A fuel injector is used to inject fuel into the combustion chamber of the dedicated EGR cylinder after initiation of the main combustion event. This post injection method overcomes flammability limits of a dedicated EGR cylinder, and increases the hydrogen (H2) and carbon monoxide (CO) in its exhaust.

Growing community of inventors

San Antonio, TX, United States of America

Raphael Gukelberger