EP0589516A2 - Dispositif silencieux pour des moteurs à combustion - Google Patents

Dispositif silencieux pour des moteurs à combustion Download PDF

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Publication number
EP0589516A2
EP0589516A2 EP93202669A EP93202669A EP0589516A2 EP 0589516 A2 EP0589516 A2 EP 0589516A2 EP 93202669 A EP93202669 A EP 93202669A EP 93202669 A EP93202669 A EP 93202669A EP 0589516 A2 EP0589516 A2 EP 0589516A2
Authority
EP
European Patent Office
Prior art keywords
tube
loudspeaker enclosure
helmholtz resonator
subvolumes
exhaust pipe
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP93202669A
Other languages
German (de)
English (en)
Other versions
EP0589516A3 (en
Inventor
Joris Adelbert Maria Nieuwendijk
Johannes Wilhelmus Theodorus Bax
André Jozef de Wachter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Koninklijke Philips Electronics NV
Philips Electronics NV
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 Koninklijke Philips Electronics NV, Philips Electronics NV filed Critical Koninklijke Philips Electronics NV
Priority to EP93202669A priority Critical patent/EP0589516A3/en
Publication of EP0589516A2 publication Critical patent/EP0589516A2/fr
Publication of EP0589516A3 publication Critical patent/EP0589516A3/en
Withdrawn legal-status Critical Current

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Classifications

    • 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
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/172—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using resonance effects
    • 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

Definitions

  • the invention relates to a silencer arrangement for combustion engines whose exhaust gases are discharged via an exhaust pipe, which silencer arrangement comprises a loudspeaker enclosure, in which a partition and a loudspeaker device secured to the partition are arranged, the partition dividing a volume bounded by the loudspeaker enclosure into two subvolumes, an acoustic tube secured to the loudspeaker enclosure and acoustically coupled to one of the subvolumes, one end of the acoustic tube being situated near one end of the exhaust pipe, a Helmholtz resonator, and a control unit which drives the loudspeaker device in response to measurement signals.
  • a silencer of the type defined in the opening paragraph is known from EP 0,481,450 A1.
  • the control unit By means of the control unit the sound at the end of the exhaust pipe is analyzed, amplified and phase-shifted.
  • the control unit subsequently drives a loudspeaker, which emits sound via the acoustic tube, which sound interferes with the sound produced by the exhaust gas and thus reduces the noise.
  • the Helmholtz resonator is formed by the loudspeaker enclosure. If the acoustic tube is long (approximately 20 cm or longer) the air in the tube no longer behaves as a acoustic mass and the tube functions as an acoustic transmission channel.
  • the silencer arrangement in accordance with the invention is characterised in that the Helmholtz resonator is acoustically coupled to the tube via an opening in a side wall of the tube, the Helmholtz resonator containing an acoustic damping material and the quality factor Q Helmh. of the Helmholtz resonator being greater than 1 and smaller than 3, and the two subvolumes communicate acoustically with one another via a port in the partition.
  • the coupling of the Helmholtz resonator to the acoustic tube via an opening in the side wall of the tube reduces undesired distortions and phase errors in the acoustic output signal. As a result of this, the acoustic resonance peaks outside the operating range are reduced, which improves the performance of the silencer arrangement. Since the two subvolumes communicate via a port larger loudspeakers can be used with the same enclosure volume, so that the acoustic power increases or the same acoustic power can be produced with less electric power.
  • a port is to be understood to mean a tube or an opening.
  • a Helmholtz resonator which is acoustically coupled to a long tube via an opening in a side wall of the tube is known per se from EP 0,429,121 A1.
  • a loudspeaker enclosure having two subvolumes communicating via an opening in a partition is known per se from US-A-5,025,885.
  • the use of such a loudspeaker enclosure en Helmholtz resonator in a silencer arrangement for combustion engines is new and combines the advantages, yielding a very advantageous novel silencer arrangement for use with combustion engines.
  • An embodiment of the silencer arrangement in accordance with the invention is characterised in that a further acoustic tube is secured to the loudspeaker enclosure and is acoustically coupled to one of the subvolumes, one end of the further acoustic tube being situated near one end of the exhaust pipe, and the Helmholtz resonator being acoustically coupled to the further tube via an opening in a side wall of the further tube.
  • the Helmholtz resonator can be mechanically connected to both tubes, resulting in a rugged construction of the acoustic tubes with the Helmholtz resonator.
  • a further embodiment is characterized in that the loudspeaker enclosure is mainly made of a non-metallic material such as wood or a synthetic material.
  • the loudspeaker enclosure can be manufactured by means of a method known from the production of loudspeaker enclosures for audio purposes. Both the loudspeaker and the enclosure should be protected from excessive heating by arranging them at adequate distances from hot parts and, if required, by the use of thermally insulating materials and tubes.
  • the invention also relates to a vehicle comprising a silencer arrangement as characterized above, which vehicle is characterized in that the loudspeaker enclosure is disposed in a inner space of the vehicle, which space is isolated from the exhaust pipe by at least one wall.
  • Figure 1 shows diagrammatically a combustion engine 1 having a exhaust pipe 3.
  • a passive acoustic silencer 5 is arranged to suppress the high-frequency noise produced by the exhaust gases.
  • a microphone 9 is arranged to measure the sound.
  • the measurement signal from the microphone 9 and from a tachometer 11 for the engine speed are applied to a control unit 13.
  • the control unit processes the measurement signals and drives a loudspeaker device comprising loudspeakers 15, 17 accommodated in a loudspeaker enclosure 19.
  • the measurement signals vary as a function of the changing operating conditions of the combustion engine. For this reason the control unit 13 also regularly adapts the drive to the loudspeakers 15, 17.
  • the loudspeaker enclosure 19 has a partition 21 dividing the volume of the loudspeaker enclosure into a first subvolume 23 of 5 litres and a second subvolume 25 of 3.5 litres.
  • the subvolumes 23, 25 communicate with one another via a pipe 27 arranged in a opening 29 in the partition 21.
  • the pipe 27 has a diameter of 47 mm and a length of approximately 14 cm.
  • the two loudspeakers 15, 17 are secured to the partition 21 at the location of two further openings in the partition.
  • the loudspeakers 15, 17 have a diaphragm of 7 inch diameter, a moving mass of approximately 10 grammes and a resonant frequency of 58 Hz, their Q T (overall quality factor with open resonant frequency) being approximately 0.15.
  • An opening 31 in the loudspeaker enclosure 19 provides the acoustic coupling between the subvolume 25 and an acoustic tube 33.
  • the acoustic tube 33 has a diameter of 100 mm and a pathlength of approximately 22 cm.
  • the acoustic tube 33 has one end secured to the loudspeaker enclosure 19 and its other end is situated near the end 7 of the exhaust pipe 3.
  • An opening 37 is formed in a wall of the tube 33. At the location of this opening 37 a short pipe 39 is secured to the tube 33 in order to provide an acoustic coupling between a Helmholtz resonator 41 and the tube 33.
  • the short pipe 39 has a diameter of 66 mm ad a length of approximately 30 mm.
  • the central axis of the pipe 39 is situated at a distance of approximately 9 cm from the end 35 of the tube 33.
  • the Helmholtz resonator 41 has a volume of approximately 0.5 to 1 litre.
  • the Helmholtz resonator 41 contains such a amount of a acoustic damping material 43 in the form of glass wool or rock wool that the quality factor Q Helmh. of the Helmholtz resonator lies between the values 1 ad 3 and is, for example, 2.
  • the loudspeaker enclosure 19 is made of a non-metallic material such as wood or a synthetic material, for example polycarbonate, polypropylene etc.
  • the material of the Helmholtz resonator 41 and the tube 33 is preferably a metal, because these parts are situated comparatively close to the exhaust pipe 3.
  • two tubes 45, 47 are secured to the loudspeaker enclosure 19 and the ends 49, 51 of the tubes are situated at opposite sides of the end 35 of the exhaust pipe.
  • the tubes 45, 47 have a diameter of 70 mm and a pathlength of approximately 22 cm.
  • Both tubes 45, 47 are acoustically coupled to a common Helmholtz resonator 61 via openings 53, 55 in the walls of the tube and via short pipes 57, 59.
  • the short pipes 57, 59 have a diameter of 47 mm and a length of approximately 35 mm.
  • the central axes of the pipes 57, 59 are situated at a distance of approximately 9 cm from the ends 49, 51 of the tubes 45, 47.
  • the volume of the Helmholtz resonator 61 is again 0.5 to 1 litre.
  • the loudspeaker enclosure 19 has been arranged in the trunk 71 of the car.
  • the loudspeaker enclosure is isolated from the exhaust pipe 7 by the bottom plate 73.
  • the loudspeaker enclosure 19 may be isolated from parts of the car by elastic and/or damping means to reduce the transmission of structural-borne sounds.
  • the tubes 47 and 49 may be detachably connected to the loudspeaker enclosure in order to simplify mounting.
  • the tubes 47 and 49 may be passed through the bottom plate 73 of the car via resilient and/or damping and/or thermally insulating feed-through means.
  • the Helmholtz resonator 41 may be constructed so as to form part of the feed-through means.
  • the present embodiments of the silencer arrangement for combustion engines can be used, for example, for actively silencing the exhaust gas noise of a car.
  • the loudspeaker enclosure containing the loudspeakers can be accommodated, for example, in the trunk of a car, the tubes extending to the exhaust pipe through the trunk bottom.
  • the loudspeaker enclosure is then mechanically isolated completely from the exhaust pipe, which enables the loudspeaker enclosure to be made of a cheap synthetic material having suitable acoustic properties.
  • the loudspeakers remote from the exhaust pipe the loudspeakers need not comply with stringent requirements as regards the resistance to high temperatures ad the moisture resistance.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Exhaust Silencers (AREA)
EP93202669A 1992-09-23 1993-09-15 Silencer arrangement for combustion engines Withdrawn EP0589516A3 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP93202669A EP0589516A3 (en) 1992-09-23 1993-09-15 Silencer arrangement for combustion engines

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP92202914 1992-09-23
EP92202914 1992-09-23
EP93202669A EP0589516A3 (en) 1992-09-23 1993-09-15 Silencer arrangement for combustion engines

Publications (2)

Publication Number Publication Date
EP0589516A2 true EP0589516A2 (fr) 1994-03-30
EP0589516A3 EP0589516A3 (en) 1995-09-20

Family

ID=26131704

Family Applications (1)

Application Number Title Priority Date Filing Date
EP93202669A Withdrawn EP0589516A3 (en) 1992-09-23 1993-09-15 Silencer arrangement for combustion engines

Country Status (1)

Country Link
EP (1) EP0589516A3 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0855846A2 (fr) * 1997-01-23 1998-07-29 Bose Corporation Dispositif d'atténuation de bruit
US6449934B1 (en) * 1995-11-13 2002-09-17 Ransomes America Corporation Electric riding mower with motor generator set and noise abatement
US7281605B2 (en) * 2003-05-02 2007-10-16 Owens-Corning Fiberglas Technology Ii, Llc Mufflers with enhanced acoustic performance at low and moderate frequencies

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0429121A1 (fr) * 1989-11-16 1991-05-29 Koninklijke Philips Electronics N.V. Système de haut-parleurs comportant un résonateur de Helmholtz couplé à un tube acoustique
US5025885A (en) * 1989-07-14 1991-06-25 Bose Corporation Multiple chamber loudspeaker system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5025885A (en) * 1989-07-14 1991-06-25 Bose Corporation Multiple chamber loudspeaker system
EP0429121A1 (fr) * 1989-11-16 1991-05-29 Koninklijke Philips Electronics N.V. Système de haut-parleurs comportant un résonateur de Helmholtz couplé à un tube acoustique

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
L.E. KINSLER & A.R. FREY 'Fundamentals of Acoustics' 1962 , WILEY & SONS , NEW YORK, USA * page 186 - page 213 * *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6449934B1 (en) * 1995-11-13 2002-09-17 Ransomes America Corporation Electric riding mower with motor generator set and noise abatement
US6644004B2 (en) 1995-11-13 2003-11-11 Textron Inc. Electric riding mower with motor generator set and noise abatement
EP0855846A2 (fr) * 1997-01-23 1998-07-29 Bose Corporation Dispositif d'atténuation de bruit
EP0855846A3 (fr) * 1997-01-23 1999-06-16 Bose Corporation Dispositif d'atténuation de bruit
US7281605B2 (en) * 2003-05-02 2007-10-16 Owens-Corning Fiberglas Technology Ii, Llc Mufflers with enhanced acoustic performance at low and moderate frequencies

Also Published As

Publication number Publication date
EP0589516A3 (en) 1995-09-20

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