WO1993005282A1 - Pot d'echappement - Google Patents

Pot d'echappement Download PDF

Info

Publication number
WO1993005282A1
WO1993005282A1 PCT/GB1992/001594 GB9201594W WO9305282A1 WO 1993005282 A1 WO1993005282 A1 WO 1993005282A1 GB 9201594 W GB9201594 W GB 9201594W WO 9305282 A1 WO9305282 A1 WO 9305282A1
Authority
WO
WIPO (PCT)
Prior art keywords
chamber
noise
muffler according
conduit
muffler
Prior art date
Application number
PCT/GB1992/001594
Other languages
English (en)
Inventor
Owen Jones
Michael Charles John Trinder
Original Assignee
Active Noise And Vibration Technologies Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Active Noise And Vibration Technologies Inc. filed Critical Active Noise And Vibration Technologies Inc.
Priority to AU24891/92A priority Critical patent/AU668100B2/en
Priority to KR1019940700569A priority patent/KR100272313B1/ko
Priority to JP5505036A priority patent/JPH07500646A/ja
Priority to EP92918267A priority patent/EP0602091A1/fr
Publication of WO1993005282A1 publication Critical patent/WO1993005282A1/fr
Priority to US08/599,642 priority patent/US5619020A/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/06—Silencing apparatus characterised by method of silencing by using interference effect
    • F01N1/065—Silencing apparatus characterised by method of silencing by using interference effect by using an active noise source, e.g. speakers
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/10—Applications
    • G10K2210/128—Vehicles
    • G10K2210/1282—Automobiles
    • G10K2210/12822—Exhaust pipes or mufflers
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/301—Computational
    • G10K2210/3011—Single acoustic input
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3217—Collocated sensor and cancelling actuator, e.g. "virtual earth" designs
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3219—Geometry of the configuration
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/30—Means
    • G10K2210/321—Physical
    • G10K2210/3228—Shunts
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
    • G10K2210/50—Miscellaneous
    • G10K2210/502—Ageing, e.g. of the control system

Definitions

  • the present invention relates to a muffler for muffling noise in a fluid flow, for example the exhaust flow from of an internal combustion engine.
  • the exhaust pipe is caused to pass through a chamber, in which a loudspeaker is mounted.
  • the loudspeaker is used to produce anti-noise in the chamber, for cancelling the exhaust noise.
  • the portion of the exhaust pipe passing through the chamber should be perforated.
  • exhaust gases pass out through the perforations located towards the chamber inlet. This escape of exhaust gases results in a pressure differential along the length of the perforated portion of the pipe.
  • an inflow pipe passes completely through the chamber and terminates within an outflow pipe.
  • a muffler for muffling noise in a fluid flow comprising a chamber, means for injecting anti-noise into the chamber, a conduit for conveying a fluid stream, means for receiving fluid flowing from the conduit, and coupling means including a radial aperture between the conduit and the receiving means, for acoustically coupling the chamber to the fluid stream, wherein the coupling means is arranged such that the chamber becomes pressurised in use, such as to restrict flow of fluid from the fluid stream through the chamber.
  • the muffler is arranged to act as an acoustical filter.
  • the conduit passes through the chamber, teiminating just short of an opening in a wall of the chamber, in which case the conduit te ⁇ nination and the aperture can be coaxially aligned and the acoustic coupling means comprises the gap between the conduit termination and the opening.
  • the conduit may run along the side of a chamber, the acoustic coupling means comprising a slot coupling the interior of the chamber with the gas flow in the conduit.
  • the coupling means may also include bridging members for physically coupling the conduit to the receiving means.
  • the internal diameter of the conduit is less than the internal diameter of the receiving means.
  • the muffler will include a microphone.
  • the means for injecting anti-noise into the chamber comprises a loudspeaker.
  • a plurality of loudspeakers may be employed.
  • the passive frequency response of the muffler may be tailored by resistively or capacitively loading the loudspeaker.
  • the drive circuit for the loudspeaker may include an amplifier circuit with a gain/frequency response configured to drive the loudspeaker so that its frequency response is modified to have a desired characteristic over a given frequency range.
  • the muffler may be employed in an active noise cancellation system, for example in the exhaust system of an internal combustion engine.
  • Figure 1 is a side view of a muffler according to the present invention.
  • Figure 2 is a diagramatic representation of a muffler according to the present invention, employed in an active noise cancellation system.
  • a muffler 1 comprises a rectangular box 2 formed from sheet metal.
  • An outflow pipe 3 extends outwardly from a circular opening 4 located in a wall 2a of the box 2.
  • An inflow pipe 5 extends through a wall 2b of the box 2, opposite the opening 4, to a point just short of and in axial alignment with the opening 4.
  • the inflow pipe 5 terminates 25 mm short of the aperture 4.
  • the space between the end of the inflow pipe and the opening 4 defines a radial aperture 13 which in use produces an acoustical coupling between a chamber 10 and gas flowing from the inflow pipe 5 to the outflow pipe 3, as will be explained in more detail hereinafter.
  • a pair of partitions 8 and 9 run parallel to the inflow pipe 5 and divide the box into three chambers.
  • a central chamber 10 is defined between the partitions 8 and 9.
  • Two moving coil loudspeakers 6 and 7 are mounted in the partitions 8 and 9 respectively, such that they are directed towards the inflow pipe 5.
  • a microphone 11 is mounted on the outflow pipe 3, adjacent to where it joins the box 2.
  • An electronic processing unit 12, such as disclosed in our copending UK Patent Application No. 9116433.5 has an input which is electrically coupled to the microphone 11 and outputs which are coupled to respective speakers 6 and 7.
  • Sound emerging from the muffler and propagating along the outflow pipe 3 is sensed by the microphone 11 which sends an electrical signal representative of this sound to the input of the processing unit 12.
  • the processing unit 12 outputs electrical cancelling signals which drive the speakers 6 and 7 to produce anti-noise.
  • the anti-noise mixes with the engine noise in the central chamber 10, which results in the sound propagating along the outflow pipe 3 having a much smaller amplitude than that propagating along the inflow pipe 5.
  • the passive performance of the muffler in this region can be modified by reducing the electrical damping of the loudspeaker. This may be achieved by either connecting a low value resistor, for example 5 ohms, or a capacitance, for example 1000 microfarrads, in parallel with each loudspeaker 6 and 7.
  • a low value resistor for example 5 ohms
  • a capacitance for example 1000 microfarrads
  • the loudspeaker may be driven by circuits (within element 12) including amplifiers with frequency/gain characteristics selected to modify the natural characteristics of the loudspeakers.
  • the loudspeakers 6 and 7 may be made to appear acoustically as simple masses over a given frequency range. This is achieved by arranging for the circuits driving the loudspeakers 6 and 7, to have output impedances which are the complex conjugates of the loudspeaker impedances over the given frequency range;
  • moving coil loudspeakers have been employed, other forms of transducer may usefully be employed such as piezo electric devices.
  • inflow pipe 5 has been shown entering the chamber 1 through a wall opposite the aperture 4, alternative arrangements may be employed so long as the inflow pipe 5 terminates in alignment with an adjacent to the opening 4 so as to define a radial aperture such as the aperture 13.
  • the position of the microphone 11 is not critical. Consequently, the microphone 11 may be placed in any convenient position e.g. within the central chamber 10 or at the discharge end of the outflow pipe 3.
  • the passive attenuation of higher frequency noise means that the processing unit 12 may be of a simple design since it need only function over a restricted frequency range.
  • the muffler includes a compliant membrane (not shown) to isolate the region of the chamber 10 containing the loudspeakers 6 and 7 from the pipe 5, the membrane being substantially acoustically transparent for transmission of the anti-noise, but mechanically isolating gas from the exhaust from reaching the loudspeakers.
  • the in low pipe 5 may be connected to the outflow pipe 3 on its lower side, thereby extending across the lower side of the aperture 13 in order to provide a flow path for liquid condensate in the pipe 5 to the outflow pipe 3. In this way an accumulation of liquid condensates in the chamber 10 is avoided.
  • the term anti-noise is used to mean acoustic signals controlled in phase and amplitude so as to tend to cancel an unwanted noise.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Silencers (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

Pot d'échappement destiné à amortir le bruit produit par la ciruclation d'un fluide, tel que les gaz d'échappement dans un moteur à combustion interne comprenant une chambre (10), des haut-parleurs (7) destinés à injecter des signaux anti-bruit dans ladite chambre sous le contrôle de circuits de traitement (42) en fonction du bruit résiduel détecté à l'aide d'un microphone (11). Les gaz circulent d'un conduit d'admission (5) vers un conduit de sortie (3) en passant par une ouverture radiale (13) reliant accoustiquement la chambre (10) et la circulation de gaz, de façon à permettre le mélange des signaux anti-bruit avec le bruit présent dans la circulation de gaz et à produire ainsi l'annulation du bruit. Le couplage est réalisé de telle sorte que lors de l'utilisation, la chambre (10) est mise sous pression par la circulation des gaz de façon à limiter la circulation de gaz chauds à travers la chambre et à constituer ainsi un environnement sans effets néfastes pour les haut-parleurs.
PCT/GB1992/001594 1991-08-29 1992-08-28 Pot d'echappement WO1993005282A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
AU24891/92A AU668100B2 (en) 1991-08-29 1992-08-28 Muffler
KR1019940700569A KR100272313B1 (ko) 1991-08-29 1992-08-28 머플러
JP5505036A JPH07500646A (ja) 1991-08-29 1992-08-28 消音器
EP92918267A EP0602091A1 (fr) 1991-08-29 1992-08-28 Pot d'echappement
US08/599,642 US5619020A (en) 1991-08-29 1996-02-09 Muffler

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB919118779A GB9118779D0 (en) 1991-08-29 1991-08-29 Muffler
GB9118779.9 1991-08-29

Publications (1)

Publication Number Publication Date
WO1993005282A1 true WO1993005282A1 (fr) 1993-03-18

Family

ID=10700805

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1992/001594 WO1993005282A1 (fr) 1991-08-29 1992-08-28 Pot d'echappement

Country Status (7)

Country Link
EP (1) EP0602091A1 (fr)
JP (1) JPH07500646A (fr)
KR (1) KR100272313B1 (fr)
AU (1) AU668100B2 (fr)
CA (1) CA2116695A1 (fr)
GB (1) GB9118779D0 (fr)
WO (1) WO1993005282A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993025998A1 (fr) * 1992-06-08 1993-12-23 Ford Motor Company Limited Silencieux a suppression de bruit active pour un vehicule automobile
DE4342133A1 (de) * 1993-12-10 1995-06-14 Nokia Deutschland Gmbh Anordnung zur aktiven Schalldämpfung
EP0674097A1 (fr) * 1994-02-22 1995-09-27 ELECTRONIC SOUND ATTENUATION S.p.A. Silencieux actif de gaz d'échappement
EP0916817A2 (fr) 1997-11-18 1999-05-19 LEISTRITZ AG & CO. Abgastechnik Silencieux actif
FR2843999A1 (fr) * 2002-09-03 2004-03-05 Comptoir De La Technologie Dispositif actif d'attenuation du bruit de bouche au niveau d'un conduit d'echappement ou d'admission
EP2105587B1 (fr) * 2008-03-27 2012-07-04 J. Eberspächer GmbH & Co. KG Installation de gaz d'échappement

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989007701A1 (fr) * 1988-02-19 1989-08-24 Noise Cancellation Technologies, Inc. Systeme actif d'attenuation sonore pour systemes d'echappement d e moteur et analogue
US5088575A (en) * 1990-09-13 1992-02-18 Nelson Industries, Inc. Acoustic system with transducer and venturi

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5097923A (en) * 1988-02-19 1992-03-24 Noise Cancellation Technologies, Inc. Active sound attenation system for engine exhaust systems and the like
JP2882491B2 (ja) * 1989-11-24 1999-04-12 株式会社日本自動車部品総合研究所 吸気音制御装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1989007701A1 (fr) * 1988-02-19 1989-08-24 Noise Cancellation Technologies, Inc. Systeme actif d'attenuation sonore pour systemes d'echappement d e moteur et analogue
US5088575A (en) * 1990-09-13 1992-02-18 Nelson Industries, Inc. Acoustic system with transducer and venturi

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 015, no. 505 (M-1194)1 October 1991 & JP,A,32 22 854 ( NIPPON SOKEN INC ) 1 October 1991 *
PATENT ABSTRACTS OF JAPAN vol. 016, no. 226 (M-1254)26 May 1992 & JP,A,40 43 806 ( NISSAN MOTOR CO LTD ) *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1993025998A1 (fr) * 1992-06-08 1993-12-23 Ford Motor Company Limited Silencieux a suppression de bruit active pour un vehicule automobile
DE4342133A1 (de) * 1993-12-10 1995-06-14 Nokia Deutschland Gmbh Anordnung zur aktiven Schalldämpfung
EP0657630A1 (fr) * 1993-12-10 1995-06-14 NOKIA TECHNOLOGY GmbH Arrangement d'atténuation active de son
US5466899A (en) * 1993-12-10 1995-11-14 Nokia Technology Arrangement for active sound damping
EP0674097A1 (fr) * 1994-02-22 1995-09-27 ELECTRONIC SOUND ATTENUATION S.p.A. Silencieux actif de gaz d'échappement
EP0916817A2 (fr) 1997-11-18 1999-05-19 LEISTRITZ AG & CO. Abgastechnik Silencieux actif
EP0916817A3 (fr) * 1997-11-18 2002-10-30 Faurecia Abgastechnik GmbH Silencieux actif
FR2843999A1 (fr) * 2002-09-03 2004-03-05 Comptoir De La Technologie Dispositif actif d'attenuation du bruit de bouche au niveau d'un conduit d'echappement ou d'admission
WO2004022931A1 (fr) * 2002-09-03 2004-03-18 Comptoir De La Technologie Dispositif actif d'attenuation du bruit de bouche au niveau d'un conduit d'echappement ou d'admission
EP2105587B1 (fr) * 2008-03-27 2012-07-04 J. Eberspächer GmbH & Co. KG Installation de gaz d'échappement

Also Published As

Publication number Publication date
AU2489192A (en) 1993-04-05
JPH07500646A (ja) 1995-01-19
KR100272313B1 (ko) 2000-11-15
CA2116695A1 (fr) 1993-03-18
EP0602091A1 (fr) 1994-06-22
AU668100B2 (en) 1996-04-26
GB9118779D0 (en) 1991-10-16

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