Patent US5828759A successfully refreshed from Google Patents.
US5828759A
Expired / Lapsed
US
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System and method for reducing engine noise
Assignee: Siemens Canada Ltd
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Filing: 1995-11-30
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Granted: 1998-10-27
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Expires: 2015-11-30
Abstract
Abstract A system and method for reducing noise from an internal combustion engine using a duct housing receiving induction air flow to the engine. A space is defined within the duct housing surrounding a speaker enclosure associated with a speaker facing an open space upstream of the annular space. A sound transducer at the axial location where the annular space opens into the open space generates electrical signals corresponding to engine noise propagating through the air induction ducting. The signals are amplified and phase shifted driving the speaker to output cancelling noises or sounds so as to at least reduce engine noise from the annular space. The speaker enclosure length is set to enhance speaker performance in selected frequency bands of engine noise.
Inventors
- 👤 Gary Everingham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:36
CPC Classifications
F; F02; F02M; F02M35/00; F02M35/12; F02M35/1244; F02M35/125; G; G10; G10K; G10K11/00; G10K11/16; G10K11/175; G10K11/178; G10K11/1785; G10K11/17857; G10K11/17861; G10K11/1787; G10K11/17873; G10K2210/00; G10K2210/10; G10K2210/112; G10K2210/128; G10K2210/1282; G10K2210/12822; G10K2210/30; G10K2210/321; G10K2210/3214; G10K2210/3219; G10K2210/3227; G10K2210/32272; G10K2210/50; G10K2210/509
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
268 words
A system for reducing noise produced by an internal combustion engine having an air induction system for providing an air flow to supply said engine including: a main duct for receiving all of said air flow passing through said air induction system to said engine, said main duct including a curvilinear section gradually enlarging from a small diameter portion to a substantially larger diameter portion; said system also including a speaker enclosure positioned within said larger diameter portion of said main duct, said speaker enclosure also having a curvilinear form and said speaker enclosure coaxially positioned within said larger diameter portion of said main duct curvilinear section so as to provide an annular flow space within said main duct larger diameter portion surrounding a perimeter portion of said speaker enclosure, said air flow passing into said annular flow space; a speaker coaxially aligned within said enclosure, said speaker having a cone facing towards the air flow into said main duct larger diameter portion, said speaker enclosure allowing sound to be projected out from one end thereof from said speaker and away from said main duct larger diameter portion; a sound transducer assembly comprising a sound transducer positioned to generate electrical signals corresponding to engine noises propagated along said main duct; said sound transducer assembly further comprising an audio amplifier connected to receive and amplify said electrical signals, said audio amplifier having an output operably connected to said speaker to drive said speaker with said amplified signals phase shifted by 180°, to generate cancelling sound from said speaker broadcast out from said main duct curvilinear section larger diameter portion.
Claim 2
Independent Claim
268 words
A system for reducing noise produced by an internal combustion engine having an air induction system for providing an air flow to supply said engine including: a main duct for receiving all of said air flow passing through said air induction system to said engine, said main duct including a curvilinear section gradually enlarging from a small diameter portion to a substantially larger diameter portion; said system also including a speaker enclosure positioned within said larger diameter portion of said main duct, said speaker enclosure also having a curvilinear form and said speaker enclosure coaxially positioned within said larger diameter portion of said main duct curvilinear section so as to provide an annular flow space within said main duct larger diameter portion surrounding a perimeter portion of said speaker enclosure, said air flow passing into said annular flow space; a speaker coaxially aligned within said enclosure, said speaker having a cone facing towards the air flow into said main duct larger diameter portion, said speaker enclosure allowing sound to be projected out from one end thereof from said speaker and away from said main duct larger diameter portion; a sound transducer assembly comprising a sound transducer positioned to generate electrical signals corresponding to engine noises propagated along said main duct; said sound transducer assembly further comprising an audio amplifier connected to receive and amplify said electrical signals, said audio amplifier having an output operably connected to said speaker to drive said speaker with said amplified signals phase shifted by 180°, to generate cancelling sound from said speaker broadcast out from said main duct curvilinear section larger diameter portion.
Claim 3
Dependent Claim
63 words
The system according to claim 1 wherein said speaker enclosure is closed at one end and open at another end facing opposite the direction from which air flows into said main duct annual spacing, and said speaker is mounted within said enclosure facing out said open another end of said enclosure to be facing said air flow into said main duct annular space.
Claim 4
Dependent Claim
21 words
The system according to claim 2 wherein said annular flow space terminates at said open another end of said speaker enclosure.
Claim 5
Dependent Claim
47 words
The system according to claim 3 wherein said sound transducer is mounted at a point with respect to said main duct curvilinear section larger diameter portion where said annular flow space terminates, and approximately aligned with a plane at the open another end of said speaker enclosure.
Claim 6
Dependent Claim
21 words
The system according to claim 3 further including a sound absorbing material within the closed one end of said speaker enclosure.
Claim 7
Independent Claim
170 words
A method of reducing noise generated by an internal combustion engine having an air induction system having an air duct receiving the air flow into said engine, said method comprising the steps of; mounting a speaker coaxially within an enclosure and mounting said enclosure coaxially within a portion of said air induction system air duct defining a gradually increasing diameter curvilinear section having a small diameter portion and a large diameter portion so as to define an annular flow space within said air duct curvilinear section larger diameter portion receiving all air flow passing through said air duct and to position said speaker to project sound oppositely to the direction of air flow into said air duct annular flow space; generating electrical signals corresponding to said engine noise at an approximate point in said air induction system air duct whereat said speaker is located; amplifying said signals and driving said speaker with said amplified signals which are phase shifted so as to generate sound from said speaker cancelling engine noise.
Claim 8
Independent Claim
170 words
A method of reducing noise generated by an internal combustion engine having an air induction system having an air duct receiving the air flow into said engine, said method comprising the steps of; mounting a speaker coaxially within an enclosure and mounting said enclosure coaxially within a portion of said air induction system air duct defining a gradually increasing diameter curvilinear section having a small diameter portion and a large diameter portion so as to define an annular flow space within said air duct curvilinear section larger diameter portion receiving all air flow passing through said air duct and to position said speaker to project sound oppositely to the direction of air flow into said air duct annular flow space; generating electrical signals corresponding to said engine noise at an approximate point in said air induction system air duct whereat said speaker is located; amplifying said signals and driving said speaker with said amplified signals which are phase shifted so as to generate sound from said speaker cancelling engine noise.
Claim 9
Dependent Claim
38 words
The method according to claim 6 wherein said step of generating electrical signals corresponding to engine noise includes the step of positioning a microphone at the approximate location of said speaker in said air induction system air duct.
Claim 10
Dependent Claim
31 words
The method according to claim 6 further including the step of adjusting the axial length of said enclosure to enhance speaker performance in a dominant frequency band of said engine noise.
Claim 11
Dependent Claim
45 words
The method according to claim 8 wherein the length L of said speaker enclosure is set substantially according to the formula: L=(C/4fs)-1.9r, where C is the speed of sound in air, fs is the selected frequency, and r is the radius of the speaker enclosure.
References Cited (Backward Citations)
US3936606A
Cited
US4410065A
Cited
US4665549A
Cited
US4876722A
Cited
US5446790A
Cited
US5457749A
Cited
US5229556A
Cited
US5432857A
Cited
US5319165A
Cited
US5426703A
Cited
US5170019A
Cited
JPH0598928A
Cited
US5550334A
Cited
JPH05134684A
Cited
US5176114A
Cited
US5336856A
Cited
JPH06101444A
Cited
US5426705A
Cited
US5471537A
Cited
US5452577A
Cited
US5677958A
Cited
US5466899A
Cited
US5513266A
Cited
US5541373A
Cited
US5693918A
Cited
US5703337A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-26 | 2002-04-27 | 2002-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-26 | 2006-04-27 | 2006-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-26 | 2010-04-27 | 2010-10-27 | $7700.00 | Window Closed / Lapsed |