# US 8,539,768 B2 · Exhaust bypass system for turbocharged engine with dedicated exhaust gas recirculation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,539,768 B2 - Document ID: US8539768B2 - Status: Granted - Kind: B2 - Application number: 13/104,555 - Filed: 2011-05-10 - Published: 2012-11-15 - Granted: 2013-09-24 - Earliest claimed: 2011-05-10 - Assignees: GM Global Technology Operations LLC - Applicants: Alan W. Hayman; Rodney E. Baker - Inventors: Alan W. Hayman; Rodney E. Baker - Web page: https://patentgrep.com/patent/US8539768B2 ## CPC - F02B 37/183: {Arrangements of bypass valves or actuators therefor} - F01N 13/10: of exhaust manifolds {(with cooling jacket F01N3/046)} - F02M 26/09: Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine - F02M 26/04: with a single turbocharger - Y02T 10/12: Improving ICE efficiencies - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A turbocharger assembly for an internal combustion engine includes a bypass valve for controlling a flow of exhaust gas from a second group of exhaust ports of a cylinder head assembly. When disposed in an open position, the bypass valve allows exhaust gas from the second group of exhaust ports to combine with exhaust gas from a first group of exhaust ports to spin a turbine of the turbocharger assembly. When disposed in a closed position, the bypass valve forces the exhaust gas from the second group of exhaust ports through an Exhaust Gas Recirculation (EGR) passage to an intake manifold to establish a dedicated EGR system. ## Claims ### Claim 1 An exhaust gas recirculation system for an internal combustion engine, the exhaust gas recirculation system comprising: an exhaust manifold including: a first group of runners joining to define a first exit and configured for directing exhaust gas from a first group of exhaust ports to the first exit; a second group of runners joining to define a second exit and configured for directing exhaust gas from a second group of exhaust ports to the second exit; and an EGR bypass passage in fluid communication with the second group of runners and the second exit, and defining a bypass exit, wherein the EGR bypass passage is configured for directing exhaust gas from the second group of runners to the bypass exit; a turbocharger assembly attached to the exhaust manifold and including a housing supporting a turbine and defining a first inlet in fluid communication with the first exit, and a turbine passage interconnecting the first inlet and the turbine in fluid communication, wherein the turbine passage is configured for directing exhaust gas from the first inlet to the turbine; wherein the housing of the turbocharger assembly further defines a second inlet in fluid communication with the second exit, and a housing bypass passage interconnecting the second inlet and the turbine passage in fluid communication, wherein only the housing bypass passage connects the second inlet and the turbine passage in fluid communication, and wherein the housing bypass passage is configured for directing exhaust gas from the second inlet to the turbine; wherein the turbocharger assembly includes a bypass valve supported by the housing and disposed within the housing bypass passage, wherein the bypass valve is moveable between an open position and a closed position, wherein the bypass valve is configured for allowing a flow of exhaust gas through the housing bypass passage when in the open position, and wherein the bypass valve is configured to block the flow of exhaust gas through the housing bypass passage when in the closed position to block the flow of exhaust gas between the second group of exhaust ports and the turbine; an EGR passage attached to the exhaust manifold and in fluid communication with the bypass exit, wherein the EGR passage is configured for directing exhaust gas from the bypass exit to an intake manifold; and an EGR control valve disposed within the EGR passage and moveable between an open position and a closed position, wherein the EGR control valve is configured to allow a flow of exhaust gas through the EGR passage when in the open position, and wherein the EGR control valve is configured to block the flow of exhaust gas through the EGR passage when in the closed position. ### Claim 2 (depends on 1) The exhaust gas recirculation system as set forth in claim 1 wherein the EGR control valve is disposed in the open position when the bypass valve is disposed in the closed position, and wherein the EGR control valve is disposed in the closed position when the bypass valve is disposed in the open position. ### Claim 3 (depends on 1) The exhaust gas recirculation system as set forth in claim 1 wherein the first group of runners includes a pre-defined number of runners, and the second group of runners includes a pre-defined number of runners, with the pre-defined number of runners of the first group of runners equal to the pre-defined number of runners of the second group of runners. ### Claim 4 (depends on 3) The exhaust gas recirculation system as set forth in claim 3 wherein the pre-defined number of runners of the first group of runners is equal to two (2), and the pre-defined number of runners of the second group of runners is equal to two (2). ### Claim 5 (depends on 1) The exhaust gas recirculation system as set forth in claim 1 wherein the bypass valve includes a variable intermediate position disposed between the open position and the closed position of the bypass valve, wherein the variable intermediate position is adjustable to regulate a flow of exhaust gas between both the housing bypass passage and the EGR bypass passage. ### Claim 6 (depends on 1) The exhaust gas recirculation system as set forth in claim 1 wherein the bypass valve includes a flapper rotatably mounted to the housing and rotatable about a rotation axis between the open position and the closed position of the bypass valve. ### Claim 7 (depends on 6) The exhaust gas recirculation system as set forth in claim 6 wherein the turbocharger assembly includes a lever coupled to the flapper and configured for rotating the flapper about the rotation axis. ### Claim 8 (depends on 1) The exhaust gas recirculation system as set forth in claim 1 wherein the turbocharger assembly further includes a waste gate configured for controlling the flow of exhaust gas to the turbine. ### Claim 9 An internal combustion engine for a vehicle, the internal combustion engine comprising: a cylinder head assembly defining a first group of exhaust ports and a second group of exhaust ports; an exhaust manifold attached to the cylinder head assembly, the exhaust manifold including: a first group of runners in fluid communication with the first group of exhaust ports and defining a first exit, wherein the first group of runners is configured for directing exhaust gas from the first group of exhaust ports to the first exit; a second group of runners in fluid communication with the second group of exhaust ports and defining a second exit, wherein the second group of runners is configured for directing exhaust gas from the second group of exhaust ports to the second exit; and an EGR bypass passage in fluid communication with the second group of runners and the second exit, and defining a bypass exit, wherein the EGR bypass passage is configured for directing exhaust gas from the second group of runners to the bypass exit; a turbocharger assembly attached to the exhaust manifold and including a housing supporting a turbine and defining a first inlet in fluid communication with the first exit and a turbine passage interconnecting the first inlet and the turbine in fluid communication, wherein the turbine passage is configured for directing exhaust gas from the first inlet to the turbine; wherein the housing of the turbocharger assembly further defines a second inlet in fluid communication with the second exit, and a housing bypass passage interconnecting the second inlet and the turbine passage in fluid communication, wherein only the housing bypass passage connects the second inlet and the turbine passage in fluid communication, and wherein the housing bypass passage is configured for directing exhaust gas from the second inlet to the turbine; and wherein the turbocharger assembly includes a bypass valve supported by the housing and disposed within the housing bypass passage, wherein the bypass valve is moveable between an open position and a closed position, wherein the bypass valve is configured for allowing a flow of exhaust gas through the housing bypass passage when in the open position, and wherein the bypass valve is configured to block the flow of exhaust gas through the housing bypass passage when in the closed position to block the flow of exhaust gas between the second group of exhaust ports and the turbine. ### Claim 10 (depends on 9) The internal combustion engine as set forth in claim 9 wherein the first group of exhaust ports includes a pre-defined number of exhaust ports, and the second group of exhaust ports includes a pre-defined number of exhaust ports, with the pre-defined number of exhaust ports of the first group of exhaust ports is equal to the pre-defined number of exhaust ports of the second group of exhaust ports. ### Claim 11 (depends on 10) The internal combustion engine as set forth in claim 10 wherein the pre-defined number of exhaust ports of the first group of exhaust ports is equal to two (2), and the pre-defined number of exhaust ports of the second group of exhaust ports is equal to two (2). ### Claim 12 (depends on 9) The internal combustion engine as set forth in claim 9 further comprising an EGR passage attached to the exhaust manifold and in fluid communication with the bypass exit, wherein the EGR passage is configured for directing exhaust gas from the bypass exit to an intake manifold. ### Claim 13 (depends on 12) The internal combustion engine as set forth in claim 12 further comprising an EGR control valve disposed within the EGR passage and moveable between an open position and a closed position, wherein the EGR control valve is configured to allow a flow of exhaust gas through the EGR passage when in the open position, and wherein the EGR control valve is configured to block the flow of exhaust gas through the EGR passage when in the closed position. ### Claim 14 (depends on 13) The internal combustion engine as set forth in claim 13 wherein the EGR control valve is disposed in the open position when the bypass valve is disposed in the closed position, and wherein the EGR control valve is disposed in the closed position when the bypass valve is disposed in the open position. ### Claim 15 (depends on 9) The internal combustion engine as set forth in claim 9 wherein the bypass valve includes a variable intermediate position disposed between the open position and the closed position of the bypass valve, wherein the variable intermediate position is adjustable to regulate a flow of exhaust gas between both the housing bypass passage and the EGR bypass passage. ### Claim 16 (depends on 9) The internal combustion engine as set forth in claim 9 wherein the bypass valve includes a flapper rotatably mounted to the housing and rotatable about a rotation axis between the open position and the closed position of the bypass valve. ### Claim 17 (depends on 16) The internal combustion engine as set forth in claim 16 wherein the turbocharger assembly includes a lever coupled to the flapper and configured for rotating the flapper about the rotation axis. ### Claim 18 (depends on 17) The internal combustion engine as set forth in claim 17 further comprising an actuator coupled to the lever and configured for moving the lever to control the flapper. ### Claim 19 (depends on 9) The internal combustion engine as set forth in claim 9 wherein the turbocharger assembly further includes a waste gate configured for controlling the flow of exhaust gas to the turbine.