# US 8,770,166 B2 · Multi-mode air induction tuning duct > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,166 B2 - Document ID: US8770166B2 - Status: Granted - Kind: B2 - Application number: 13/440,263 - Filed: 2012-04-05 - Published: 2013-10-10 - Granted: 2014-07-08 - Earliest claimed: 2012-04-05 - Assignees: GM Global Technology Operations LLC - Applicants: Eric R. Tucker - Inventors: Eric R. Tucker - Web page: https://patentgrep.com/patent/US8770166B2 ## CPC - F02M 35/108: with primary and secondary intake passages - F02M 35/10013: {Means upstream of the air filter; Connection to the ambient air} - F02M 35/1216: {by using a plurality of holes, slits, protrusions, perforations, ribs or the like; Surface structures; Turbulence generators} - F02M 35/1222: {by using adjustable or movable elements, e.g. valves, membranes, bellows, expanding or shrinking elements} - F02M 35/1261: {Helmholtz resonators} - F02M 35/1266: {comprising multiple chambers or compartments} - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF ## Abstract Methods and apparatuses are provided for an air inlet duct of an internal combustion engine. The air inlet duct includes a tubular housing. An inner wall has a plurality of perforations. The inner wall is disposed within the tubular housing such that the tubular housing includes at least two flow passages. A valve set is associated with a first flow passage of the at least two flow passages. The valve set selectively controls airflow through the first flow passage such that the first flow passage functions in a least one of a pass-through mode and a tuning mode. ## Claims ### Claim 1 An air inlet duct of an internal combustion engine, the air inlet duct comprising: a tubular housing; an inner wall having a plurality of perforations, wherein the inner wall is disposed within the tubular housing such that the tubular housing includes at least two flow passages; and a valve set associated with a first flow passage of the at least two flow passages, wherein the valve set selectively controls airflow through the first flow passage such that the first flow passage functions in a least one of a flow-through mode and a tuning mode. ### Claim 2 (depends on 1) The air inlet duct of claim 1 wherein the valve set comprises a first valve disposed substantially near an inlet of the first flow passage, and a second valve disposed substantially near an outlet of the first flow passage. ### Claim 3 (depends on 1) The air inlet duct of claim 1 wherein the inner wall is a planar wall that divides the tubular housing into a first side flow passage and a second side flow passage, and wherein the valve set is associated with the first side flow passage. ### Claim 4 (depends on 1) The air inlet duct of claim 1 wherein when a first valve of the valve set is in an open position, the first flow passage is configured to function in the flow-through mode. ### Claim 5 (depends on 4) The air inlet duct of claim 4 wherein when the first valve of the valve set is in a closed position, the first flow passage is configured to function in the tuning mode. ### Claim 6 (depends on 1) The air inlet duct of claim 1 wherein the inner wall is a tubular wall that, when disposed within the tubular housing, divides the tubular housing into a first outer side flow passage and a second inner flow passage. ### Claim 7 (depends on 6) The air inlet duct of claim 6 wherein when a first valve of the valve set is in an open position, the first flow passage is functioning in the flow-through mode. ### Claim 8 (depends on 7) The air inlet duct of claim 7 when the first valve of the valve set is in a closed position, the first flow passage is functioning in the tuning mode. ### Claim 9 (depends on 1) The air inlet duct of claim 1 wherein the plurality of perforations are at least one of Hemholtz resonators and Quarter Wave resonators. ### Claim 10 An air induction system for an internal combustion engine, comprising: an air cleaner; and an air inlet duct coupled to the air cleaner, the air inlet duct comprising: a tubular housing; an inner wall having a plurality of perforations, wherein the inner wall is disposed within the tubular housing such that the tubular housing includes at least two flow passages; and a valve set associated with a first flow passage of the at least two flow passages, wherein the valve set selectively controls airflow through the first flow passage such that the first flow passage functions in a least one of a pass-through mode and a tuning mode. ### Claim 11 (depends on 10) The air induction system of claim 10 wherein the valve set comprises a first valve disposed substantially near an inlet of the first flow passage, and a second valve disposed substantially near an outlet of the first flow passage. ### Claim 12 (depends on 10) The air induction system of claim 10 wherein the inner wall is a planar wall that divides the tubular housing into a first side flow passage and a second side flow passage, and wherein the valve set is associated with the first side flow passage. ### Claim 13 (depends on 10) The air induction system of claim 10 wherein when a first valve of the valve set is in an open position, the first flow passage is functioning in the flow-through mode. ### Claim 14 (depends on 13) The air induction system of claim 13 wherein when the first valve of the valve set is in a closed position, the first flow passage is functioning in the tuning mode. ### Claim 15 (depends on 10) The air induction system of claim 10 wherein the inner wall is a tubular wall that, when disposed within the tubular housing, divides the tubular housing into a first outer flow passage and a second inner flow passage. ### Claim 16 (depends on 15) The air induction system of claim 15 wherein when a first valve of the valve set is in an open position, the first flow passage is configured to function in the flow-through mode. ### Claim 17 (depends on 16) The air induction system of claim 16 when the first valve of the valve set is in a closed position, the first flow passage is configured to function in the tuning mode. ### Claim 18 (depends on 10) The air induction system of claim 10 wherein the plurality of perforations are at least one of Hemholtz resonators and Quarter Wave resonators. ### Claim 19 A vehicle, comprising: an engine system; and an air inlet duct coupled to the engine system, the air inlet duct comprising: a tubular housing; an inner wall having a plurality of perforations, wherein the inner wall is disposed within the tubular housing such that the tubular housing includes at least two flow passages; and a valve set associated with a first flow passage of the at least two flow passages, wherein the valve set selectively controls airflow through the first flow passage such that the first flow passage functions in a least one of a pass-through mode and a tuning mode.