TURBINE HOUSINGS AND TURBINE HOUSING MANIFOLDS HAVING INTEGRATED BYPASS VALVES FOR DEDICATED EXHAUST GAS RECIRCULATION ENGINES

Provided herein are turbocharger manifolds, and turbocharger and exhaust gas recirculation (EGR) systems incorporating the same. The manifold comprises a body, at least one non-dedicated EGR vein, a dedicated EGR vein, and an EGR bypass valve in fluid communication with the dedicated EGR vein, wherein the dedicated EGR vein converges with the at least one non-dedicated EGR veins downstream from the EGR bypass valve. The dedicated EGR vein is in fluid communication with an EGR conduit. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position. The manifold can comprise a one-piece construction with a turbocharger turbine housing.

BACKGROUND

During a combustion cycle of an internal combustion engine (ICE), air/fuel mixtures are provided to cylinders of the ICE. The air/fuel mixtures are compressed and/or ignited and combusted to provide output torque. Many diesel and gasoline ICEs employ a supercharging device, such as an exhaust gas turbine driven turbocharger, to compress the airflow before it enters the intake manifold of the engine in order to increase power and efficiency. Specifically, a turbocharger uses a centrifugal gas compressor that forces more air (i.e., oxygen) into the combustion chambers of the ICE than is otherwise achievable with ambient atmospheric pressure. The additional mass of oxygen-containing air that is forced into the ICE improves the engine's volumetric efficiency, allowing it to burn more fuel in a given cycle, and thereby produce more power.

SUMMARY

According to an aspect of an exemplary embodiment, a turbocharger turbine housing manifold is provided. The manifold can comprise a body, at least one non-dedicated exhaust gas recirculation (EGR) vein, a dedicated EGR vein, and an EGR bypass valve in fluid communication with the dedicated EGR vein. The dedicated EGR vein can converge with the at least one non-dedicated EGR veins downstream from the EGR bypass valve. The dedicated EGR vein can be in fluid communication with an EGR conduit. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position, wherein when the gate is in the first position the dedicated EGR vein is in fluid communication with the at least one non-dedicated EGR veins, and when the gate is in the second position the dedicated EGR vein is in fluid communication with the EGR conduit. The manifold can further comprise a wastegate valve disposed downstream from the EGR bypass valve.

According to another aspect of an exemplary embodiment, a turbocharger can include a compressor disposed within a compressor housing, a turbine mechanically coupled to the compressor and disposed within a turbine housing. The turbine housing can include a manifold having a plurality of veins which converge therein and establish fluid communication with the turbine, and at least one of the veins can be a dedicated EGR vein having an EGR bypass valve. The at least one dedicated vein can converge with at least one of the remaining veins downstream from the EGR bypass valve. The manifold and turbine housing can be a one-piece construction. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the turbine. The one or more of the at least one dedicated EGR veins can be in fluid communication with an EGR conduit. The EGR bypass valve can selectively allow or prevent fluid communication between the one or more dedicated EGR veins and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position, wherein when the gate is in the first position the dedicated EGR vein is in fluid communication with the at least one non-dedicated EGR veins, and when the gate is in the second position the dedicated EGR vein is in fluid communication with the EGR conduit. The turbocharger can further comprise a wastegate valve disposed downstream from the EGR bypass valve.

According to an aspect of an exemplary embodiment, an EGR system can comprise an internal combustion engine having an air intake manifold configured for delivering air to a plurality of cylinders, wherein one of the plurality of cylinders is a dedicated EGR cylinder, an EGR conduit in fluid communication with the air intake manifold, and a turbocharger having a turbine disposed within a turbine housing and in fluid communication with the plurality of cylinders via a turbine manifold. The turbine manifold can include a body, at least one non-dedicated EGR vein disposed within the body, a dedicated EGR vein disposed within the body in fluid communication with the dedicated EGR cylinder and the EGR conduit, and an EGR bypass valve in fluid communication with the dedicated EGR vein. The dedicated EGR vein can converge with the at least one non-dedicated EGR veins downstream from the EGR bypass valve. The EGR bypass valve can selectively allow or prevent fluid communication between the dedicated EGR vein and the EGR conduit. The EGR bypass valve can comprise a two-way valve having a gate movable from a first position to a second position, wherein when the gate is in the first position the dedicated EGR vein is in fluid communication with the at least one non-dedicated EGR veins, and when the gate is in the second position the dedicated EGR vein is in fluid communication with the EGR conduit. The manifold and turbine housing can be a one-piece construction. The system can further include a conduit in fluid communication with at least one of the one or more non-dedicated EGR cylinders and at least one of the non-dedicated EGR veins. The system can further include a conduit in fluid communication with the dedicated EGR cylinder and the dedicated EGR vein.

Other objects, advantages and novel features of the exemplary embodiments will become more apparent from the following detailed description of exemplary embodiments and the accompanying drawings.

DETAILED DESCRIPTION

Provided herein are turbocharger turbine housing manifolds, and turbochargers and exhaust gas recirculation (EGR) systems incorporating the same. The manifolds each comprise one or more EGR bypass valves which increase the efficiency of turbochargers by reducing pressure and thermal losses of exhaust gasses passing therethrough. Increases in efficiency are gained by virtue of the construction and position of the EGR bypass valves within a turbocharger manifold or turbine housing.

Referring to the drawings, wherein like reference numerals are used to identify like or identical components in the various views,FIG. 1schematically illustrates an engine assembly10including an internal combustion engine12, an air intake system14, and an exhaust system16. The air intake system14and the exhaust system16may each respectively be in fluid communication with the internal combustion engine (ICE)12, and may be in mechanical communication with each other through a turbocharger18.

ICE12includes a cylinder block11which defines a plurality of cylinders20(referenced as cylinders1-4). ICE12can be of a spark ignition or a compression ignition design. ICE12is illustrated as an inline four cylinder arrangement for simplicity. However, it is understood that the present teachings apply to any number of piston-cylinder arrangements and a variety of reciprocating engine configurations including, but not limited to, V-engines, inline engines, and horizontally opposed engines, as well as both overhead cam and cam-in-block configurations. In some specific embodiments, ICE12can comprise an inline three or six cylinder engine. In other specific embodiments, ICE12can comprise V-6, V-8, V-10, and V-12 configuration engines, among others. Each of the cylinders20can include a piston (not shown) configured to reciprocate therein, wherein a cylinder20and its respective piston can define a combustion chamber. Each of the respective cylinders20may include one or more fuel injectors29that may selectively introduce liquid fuel (as an aerosol) into each cylinder for combustion. Each of the cylinders20may be in selective fluid communication with the air intake system14to receive fresh/oxygenated air, and the cylinders20can be in selective fluid communication with the exhaust system16to expel the byproducts of combustion. Each of cylinders1,2,3, and4expel exhaust gas40away from ICE12via dedicated conduits21,22,23, and24, respectively. The exhaust gasses40can subsequently pass through one or more aftertreatment devices, such as device42, to catalyze and/or remove certain byproducts prior to exiting the exhaust system16via a tailpipe44.

The air intake system14may generally include a fresh-air inlet15, an EGR mixer26, a charge air cooler28, a throttle30, and an intake manifold32. As may be appreciated during operation of ICE12fresh air34may be ingested by the air intake system14from the atmosphere or from an associated air-cleaner assembly via the fresh-air inlet15. The throttle30may include a controllable baffle configured to selectively regulate the total flow of air through the intake system14, and ultimately into the cylinders20via the intake manifold32. The charge air cooler28is shown receiving a combination of EGR gas54and fresh air34as provided by the EGR mixer26. In some embodiments, the air intake system14can additionally or alternatively include one or more of a dedicated EGR cooler (not shown) in fluid communication with EGR conduit52and configured to cool EGR gas54prior to the EGR mixer26, and an intercooler (not shown) in fluid communication with conduit66and configured to cool compressed fresh air34prior to the EGR mixer26. In a specific embodiment (not shown), the charge air cooler28is positioned upstream from the EGR mixer26.

As mentioned above, the air intake system14and the exhaust system16may be in mechanical communication through a turbocharger18. As shown inFIG. 2, the turbocharger18includes a turbine60in fluid communication with the exhaust system16and a compressor62in fluid communication with the intake system14. The turbine60and the compressor62can be mechanically coupled via a common rotatable shaft64which extends through a bearing housing67. The turbine60can be disposed within a turbine housing61, and similarly the compressor62can be disposed within a compressor housing63. In operation, the turbine60receives exhaust gas40via manifold70. Specifically, manifold70communicates exhaust gas40from at least one of cylinders1-4to the circumferential volute, or scroll,68. Manifold70can be integrated with turbine housing61in some embodiments, for example as a one-piece construction. In some embodiments, integrating manifold70with turbine housing61provides the greatest reduction in thermal and pressure losses. In some other embodiments, manifold70is a single-piece construction separate from turbine housing61. The turbine60captures kinetic energy from the exhaust gases40, and spins the compressor62via the common shaft64. Volumetric restrictions of the exhaust gas40within the turbine housing61convert thermal energy into additional kinetic energy which is similarly captured by the turbine60. For example, volute68can be particularly optimized to effect the conversion of thermal energy to kinetic energy.

The rotation of the compressor62via the common shaft64then draws in fresh air34from the inlet15and compress it into the remainder of the intake system14. For example, the compressor62can communicate compressed air to the intake system14via conduit66. The variable flow and force of exhaust gases40can influence the amount of boost pressure that can be imparted to fresh air34by the compressor62, and subsequently the amount of oxygen capable of being delivered to cylinders20. In many instances, maximum translation of energy from exhaust gas40to compressor62is desired. In some instances, boost pressure exerted by the compressor62can be limited by an optional wastegate valve55. The wastegate valve55can divert exhaust gas40away from the turbocharger turbine60towards the tailpipe44, for example via a wastegate conduit56, thereby limiting boost pressure. Wastegate valve55can be actuated via actuator57, for example.

The engine assembly10includes a dedicated EGR system50that may directly route (e.g., via an EGR conduit52) the EGR gas54from one or more dedicated cylinders of ICE12back into the intake system14. This recirculated EGR gas54may mix with the fresh air34at the EGR mixer26, for example, and may correspondingly dilute the oxygen content of the mixture. The use of EGR can increase the efficiency in spark ignition engines. EGR can also reduce the combustion temperature and NOx production from ICE12. Routing the entire exhaust of one cylinder20, or the entire exhaust gas of less than all of cylinders20back to the intake assembly14is referred to herein as “dedicated EGR.” Dedicated EGR can include embodiments where substantially all of the exhaust gas of one cylinder20, or less than all cylinders20is routed back to the intake assembly14.

In general, manifold70comprises a body having a plurality of veins which converge therein, wherein at least one of the plurality of veins is in exclusive fluid communication with a dedicated EGR cylinder, or a plurality or dedicated EGR cylinders. Each vein within the manifold70can communicate exclusively with a dedicated conduit, such as dedicated conduits21-24, or can communicate with a plurality of dedicated conduits, such as conduits22and23. Dedicated conduits21-24are optional, and serve only to effect fluid communication between the manifold veins and the cylinders of an ICE, such as cylinders1-4or ICE12. As shown inFIG. 1as a non-limiting example, veins21′,22′,23′, and24′ fluidly communicate with dedicated conduits21,22,23, and24, respectively, the latter of which communicate with respective ICE12cylinders. In some embodiments, one or more optional dedicated conduits can converge before fluidly communicating with a manifold vein. In other embodiments, manifold70can directly communicate with ICE12cylinders. For example, manifold70can be directly affixed to cylinder block11. The manifold body can be metal, carbon fiber, or other like materials which exhibit high thermal stability.

A conduit within manifold70which is in exclusive fluid communication with a dedicated EGR cylinder or a plurality of dedicated EGR cylinders can be referred to as a dedicated EGR vein. Accordingly, as shown, vein24′ comprises a dedicated EGR vein. In some embodiments, manifold70comprises at least three veins which converge therein, wherein at least two, but less than all, of the at least three veins are dedicated EGR veins. An EGR bypass valve, such as EGR bypass valve71, is provided within the one or more dedicated EGR veins of manifold70for bypassing exhaust gas from one or more dedicated EGR cylinders to conduit52. The one or more EGR bypass valves are disposed such that exhaust gas within the dedicated EGR vein can be bypassed to EGR conduit52before contacting one or more of exhaust gas from non-dedicated EGR veins, and the turbocharger turbine, such as turbine60. For the purpose of illustration, EGR bypass valve71is shown within vein24′ in fluid communication with dedicated cylinder4(via optional dedicated conduit24), and veins21′,22′, and23′. Vein24′ converges with veins21′,22′, and23′ on the downstream side71′ of EGR bypass valve71, whereafter all veins collectively fluidly communicate with turbine60. The manifolds disclosed herein, such as manifold70, which include an integrated EGR bypass valve increase the efficiency of turbochargers, such as turbocharger18, by reducing pressure drop and thermal loss of exhaust gas, such as exhaust gas40, between one or more dedicated cylinders, such as cylinder4, and the turbocharger turbine, such as turbine60. The EGR bypass valve71configurations provided herein minimize the cylinder-to-turbine path geometric and volumetric variations between dedicated and non-dedicated cylinders.

As illustrated inFIG. 1, optional dedicated conduits21,22,23, and24are in fluid communication with corresponding veins21′,22′,23′ and24′, respectively, which converge within manifold70in order to deliver exhaust gas40to turbine60. Veins22′ and23′ are shown converging prior to converging with veins21′ and24′, however such an orientation is optional, and any permutation of non-dedicated EGR vein convergence is to be considered within the scope of this disclosure. Cylinder4is shown as a dedicated EGR cylinder by virtue of its association with an EGR bypass valve71, the latter disposed in fluid communication with vein24′, EGR conduit52, and turbine60. As desired, exhaust gas40expelled from cylinder4can be communicated to turbine60or diverted to EGR conduit52via EGR bypass valve71. In either instance of operation, the exhaust gas40of the remaining cylinders20(i.e., cylinders1-3) is communicated to the exhaust assembly16, for example via conduits56and65. In other embodiments, a plurality of cylinders, but less than all cylinders can supply 100% of their EGR gas54back to the intake assembly14. For example, cylinder1and4can supply 100% of their EGR gas54back to the intake assembly14, and the exhaust gas40of cylinder2and3can be expelled from ICE12via the exhaust assembly16. In such an embodiment, manifold70can comprise a single EGR bypass valve, such as EGR bypass valve71, disposed in fluid communication with dedicated EGR veins21′ and24′, or can alternatively comprise two individual EGR bypass valves each disposed in fluid communication with dedicated EGR veins21′ and24′, respectively. In some embodiments, conduit56and conduit65can converge within manifold70.

FIG. 3Aillustrates a perspective view of manifold70incorporated into turbine housing61.FIG. 3Bfurther illustrates a cutaway view of manifold70. Manifold70comprises a two-way EGR valve71which includes a gate72movable between a first position73and a second position74. Gate72is configured to manage fluid communication between vein24′ (the dedicated EGR vein) and one or more of vein21′, vein22′, vein23′, turbine60, and EGR conduit52. Managing fluid communication can include one or more of selectively allowing, obstructing, or preventing fluid communication. Gate72can be controlled by an EGR valve actuator75, for example, which can actuate gate72between first position73and second position74. When gate72is in first position73, EGR vein24′ is in fluid communication with one or more of vein21′, vein22′, vein23′, and turbine60, and exhaust gas within EGR vein24′ can be communicated to turbine60. When gate72is in second position74, vein24′ is in fluid communication with EGR conduit52, and exhaust gas within EGR vein24′ is communicated to EGR conduit52. Veins22′ and23′, and veins21′ and24′ are shown as converging, respectively, before being introduced to turbine60. One of skill in the art will recognize that such a configuration is optional, and the convergence of any or all veins downstream of EGR valve71within manifold70is within the scope of this disclosure.

In some embodiments, two-way EGR valve71can be replaced with two one-way valves which are one-way relative to the dedicated EGR vein24′ and prevent fluid flow from the turbine60, one or more non-dedicated EGR veins21′-23′, or EGR conduit52in an upstream direction towards dedicated vein24′ or cylinder4. A single one-way valve can occupy each of first position73and second position74, for example. Each of the one-way valves can be actuated by the same or separate actuators.