EP0243559B1 - Gas flow silencer - Google Patents

Gas flow silencer Download PDF

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Publication number
EP0243559B1
EP0243559B1 EP86401886A EP86401886A EP0243559B1 EP 0243559 B1 EP0243559 B1 EP 0243559B1 EP 86401886 A EP86401886 A EP 86401886A EP 86401886 A EP86401886 A EP 86401886A EP 0243559 B1 EP0243559 B1 EP 0243559B1
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EP
European Patent Office
Prior art keywords
envelope
sleeve
orifice
gas
chamber
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.)
Expired - Lifetime
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EP86401886A
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German (de)
French (fr)
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EP0243559A1 (en
Inventor
Jean-Paul Boet
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Sa Andre Boet SA
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Sa Andre Boet SA
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Priority to AT86401886T priority Critical patent/ATE54721T1/en
Publication of EP0243559A1 publication Critical patent/EP0243559A1/en
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    • 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
    • F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
    • F01N1/10—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling in combination with sound-absorbing materials
    • 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
    • F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
    • F01N1/084—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling the gases flowing through the silencer two or more times longitudinally in opposite directions, e.g. using parallel or concentric tubes
    • 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
    • F01N2470/00—Structure or shape of gas passages, pipes or tubes
    • F01N2470/24—Concentric tubes or tubes being concentric to housing, e.g. telescopically assembled

Definitions

  • the present invention relates to silencers for gas streams comprising means for attenuating the noises caused by the expansion of the gases.
  • the latter consists mainly of a manifold connected to the engine and a silencer connected on the one hand, to this manifold and on the other hand, to an exhaust manifold.
  • the muffler and especially the silencer prevent gases from being released into the atmosphere with such physical criteria.
  • the muffler is the predominant element in which the gases relax and cool during their journey inside while maintaining an acceptable external noise level, despite the relaxation of these gases.
  • the known silencers consist of an elongated casing provided with an inlet orifice and a gas outlet orifice, which are respectively provided at its ends and to which are connected on the one hand, the manifold and on the other hand, the exhaust manifold.
  • One or more tubes, most often pierced with radial orifices, are arranged in the envelope and can also be surrounded by a fibrous coating thus lowering the noise level.
  • the path of the exhaust gases is nevertheless, substantially direct between the two ends of the casing, which affects the noise attenuation efficiency since it is transferred directly from the inlet to the outlet of the muffler.
  • the use of such mufflers reduces the power of the engine.
  • the object of the present invention is to optimize the expansion of gases in such silencers by maximizing the volume into which said gases open.
  • the silencer of the type described above is characterized in that the end of the gas intake manifold opens into said elongated casing at the level of said inlet orifice formed in said casing.
  • the end of said ferrule located in the chamber facing the inlet orifice may have a conical shape or the like.
  • the end of said ferrule located in the chamber facing the outlet orifice may have a conical shape or the like.
  • the envelope, the ferrule and the tubing are of the shape of revolution and are coaxial with one another.
  • the transverse partition dividing the shell into two adjacent chambers, is arranged in a plane perpendicular to the axis of said shell.
  • the two rooms can have an identical volume.
  • the ferrule comprises, at least in the first chamber facing the gas inlet orifice, a plurality of radial perforations.
  • a fibrous coating can be arranged at least in the chamber of said shell facing the gas inlet orifice.
  • the ends of said ferrule may also have a conical or similar shape.
  • the axis of the ferrule can be offset from the axis of the envelope.
  • a heat engine 1 of the internal combustion type to which is connected an exhaust 2 consisting mainly of a manifold 3 connected to the exhaust ports of the engine, a silencer 4 and an exhaust manifold 5.
  • the passage of the gas stream from the engine 1 takes place through the various elements mentioned in the exhaust pipe 2.
  • the silencer 4 for the gas stream according to the invention comprises a casing 7, of substantially elongated shape, provided with an orifice 8 for the entry of gases at a end 9 of the casing and a gas outlet orifice 10 at the other end 11 of the casing.
  • the gas inlet port 8 receives one end 12 of the manifold manifold 3 and the gas outlet port 10 receives one end 15 of the exhaust manifold 5.
  • the gas stream flowing in the silencer 4 is shown symbolically by arrows 16.
  • these expansion means consist on the one hand, by a ferrule 18 held against the internal wall 19 of the casing 7 by means of fixing lugs 20 and on the other hand, by the end 15 of the exhaust manifold 5.
  • the ferrule 18 comprises a transverse partition 23 which divides the interior volume of this ferrule into two adjacent chambers 24 and 25.
  • the chamber 24 is a view of the gas inlet orifice 8 while the chamber 25 is opposite the gas outlet orifice 10.
  • a communication passage 27 is formed between the outer wall 28 of the shell 18 and the inner wall 19 of the casing 7 thus allowing the transfer and evacuation of the gases from the chamber 24 receiving the gases from the manifold, at the chamber 25 in communication with the gas outlet pipe.
  • the length L of the ferrule 18 extends over most of the length L1 of the casing 7.
  • the ferrule 18 and the casing 7 are of the shape of revolution and are coaxial around an axis 30. Similarly, the end 12 of the manifold and the end 15 of the tubing exhaust 5 are coaxial with this axis 30.
  • the ferrule 18 also comprises in the first chamber 24, radial perforations 31 which have the purpose of reducing natural frequencies due to the coupling of the two adjacent chambers.
  • the expansion means according to the invention also consist of the end 15 of the exhaust pipe 5 arranged projecting in the chamber 25 of the shell so that the face 34 of said end 15 is opposite the partition 23
  • the arrangement of the end 15 in the chamber 25 then has an additional impedance against the gases before their ejection into the atmosphere.
  • a small part of the gases also passes through the radial perforations 31 formed in the first chamber 24 of the shell.
  • the gases 16 then propagate towards the partition 23, then orient themselves towards the exhaust pipe 5, where they rush in until they are ejected into the atmosphere.
  • the acoustic level reached by the gases being further lowered by virtue of the end 15 protruding in the second chamber 25 since the end 15 increases the gas output impedance.
  • the noise level obtained at the outlet of the exhaust manifold then gives particularly satisfactory results.
  • the silencer of the invention based on the acoustic coupling between two chambers defined by the shell, makes it possible to obtain a significant acoustic attenuation of the noise.
  • this silencer can be summarized by the fact that its transfer function is that of a low-pass filter with two degrees of freedom, that is to say that all frequencies above its cutoff frequency are strongly attenuated and the frequencies below it are weakly attenuated.
  • FIG. 3 illustrates an alternative embodiment for which the ends 35 and 36 of the shell 18 have been modified. They are presented in a conical shape.
  • Figure 4 illustrates an alternative embodiment ature for which the chamber 24 facing the orifice 8 of the gas inlet is covered with a fibrous coating 40 such as a mineral wool mattress.
  • a metal casing 41 pierced with orifices 42, maintains the fibrous coating 40 against the shell 18 and the partition 23. This treatment promotes the damping of the natural frequencies.
  • FIG. 5 illustrates an alternative embodiment, which consists in off-centering the shell 18 of the envelope 7.
  • the shell is integral with the envelope by means, for example, of a weld.
  • the new geometric axis 45 of the shell 18 is offset with respect to the axis 30 of the envelope.

Abstract

1. Gaseous flow silencer of the type comprising : an elongated envelope (7) to the ends (9 and 11) of which are provided, respectively, an inlet orifice (8) which is connected to a gas inlet pipe (3), and, an outlet orifice (10) which is connected to a gas exhaust pipe (5) ; and means for expanding said gas, disposed inside said envelope (7) and constituted by a sleeve (18) comprising a transversal wall (23) separating it into two chambers (24, 25), the one (24) directed toward said inlet orifice (8) of said envelope and the other (25) directed toward said outlet orifice (10) of said envelope, said sleeve (18) providing a passage (27) with the inner surface (19) of said envelope (7) and extending on the greater part of the length of said envelope, characterized in that the end (12) of the gas inlet pipe (3) emerges in said elongated envelope (7) at the level of said inlet orifice (8) provided in said envelope.

Description

La présente invention concerne les silencieux pour courant gazeux comportant des moyens d'atténuation des bruits provoqués par la détente des gaz.The present invention relates to silencers for gas streams comprising means for attenuating the noises caused by the expansion of the gases.

Dans le cas des moteurs thermiques à combustion interne équipant les véhicules, les courants gazeux ou gaz d'échappement créés par la combustion d'un mélange air-carburant sont expulsés dans l'atmosphère à travers un pot d'échappement.In the case of internal combustion heat engines fitted to vehicles, the gas streams or exhaust gases created by the combustion of an air-fuel mixture are expelled into the atmosphere through an exhaust pipe.

Ce dernier est constitué principalement d'un collecteur raccordé au moteur et d'un silencieux relié d'un part, à ce collecteur et d'autre part, à une tubulure d'échappement. Ces gaz sont évidemment dangereux puisqu'ils arrivent dans le collecteur à des températures élevées et des pressions notamment acoustiques importantes.The latter consists mainly of a manifold connected to the engine and a silencer connected on the one hand, to this manifold and on the other hand, to an exhaust manifold. These gases are obviously dangerous since they arrive in the collector at high temperatures and in particular high acoustic pressures.

Le pot d'échappement et surtout le silencieux permettent d'éviter que les gaz soient rejetés dans l'atmosphère avec de tels critères physiques. Le silencieux constitue l'élément prépondérant dans lequel les gaz se détendent et se refroidissent durant leur parcours à l'intérieur en maintenant un niveau sonore extérieur acceptable, malgré la détente de ces gaz.The muffler and especially the silencer prevent gases from being released into the atmosphere with such physical criteria. The muffler is the predominant element in which the gases relax and cool during their journey inside while maintaining an acceptable external noise level, despite the relaxation of these gases.

Les silencieux connus sont constitués d'une enveloppe allongée pourvue d'un orifice d'entrée et d'un orifice de sortie des gaz, qui sont respectivement prévus à ses extrémités et sur lesquels se raccordent d'une part, le collecteur et d'autre part, la tubulure d'échappement. Un ou plusieurs tubes, le plus souvent percés d'orifices radiaux, sont disposés dans l'enveloppe et peuvent être entourés également d"un revêtement fibreux abaissant ainsi le niveau sonore. Le trajet des gaz d'échappement est malgré tout, sensiblement direct entre les deux extrémités de l'enveloppe, ce qui nuit à l'efficacité d'atténuation du bruit puisque celui-ci est transfére directment de l'entrée vers la sortie du silencieux. De plus, l'emploi de tels silencieux diminue la puissance du moteur.The known silencers consist of an elongated casing provided with an inlet orifice and a gas outlet orifice, which are respectively provided at its ends and to which are connected on the one hand, the manifold and on the other hand, the exhaust manifold. One or more tubes, most often pierced with radial orifices, are arranged in the envelope and can also be surrounded by a fibrous coating thus lowering the noise level. The path of the exhaust gases is nevertheless, substantially direct between the two ends of the casing, which affects the noise attenuation efficiency since it is transferred directly from the inlet to the outlet of the muffler. In addition, the use of such mufflers reduces the power of the engine.

Pour remédier à ces inconvénients, les brevets US-A-3 651 888 et FR-A-1 226 438 décrivent des silencieux pour courant gazeux du type comportant:

  • une enveloppe allongée aux extrémités de laquelle sont ménagés respectivement un orifice d'entrée auquel est raccordée une tubulure d'admission des gaz et, un orifice de sortie auquel est raccordée une tubulure d'échappement des gaz; et
  • des moyens de détente des gaz disposés à l'intérieur de ladite enveloppe et consititués par une virole comprenant une cloison transversale la partageant en deux chambres, l'une tournée vers l'orifice d'entrée de ladite enveloppe et l'autre tournée vers l'orifice de sortie de ladite enveloppe, ladite, virole ménageant un passage avec la paroi interne de ladite enveloppe et s'étendant sur la majeure partie de la longueur de ladite enveloppe.
To overcome these drawbacks, US-A-3 651 888 and FR-A-1 226 438 describe mufflers for gas streams of the type comprising:
  • an elongated casing at the ends of which are respectively provided an inlet orifice to which is connected a gas intake manifold and, an outlet orifice to which is connected a gas exhaust manifold; and
  • gas expansion means arranged inside said envelope and constituted by a ferrule comprising a transverse partition dividing it into two chambers, one facing the inlet orifice of said envelope and the other facing the 'outlet opening of said envelope, said ferrule providing a passage with the internal wall of said envelope and extending over most of the length of said envelope.

Ainsi, de tels moyens de détente évitent le transfert direct des gaz de l'entrée vers la sortie du silencieux et permettent d'atténuer fortement le bruit.Thus, such expansion means avoid the direct transfer of gases from the inlet to the outlet of the muffler and make it possible to greatly reduce the noise.

La présente invention a pour objet d'optimiser la détente de gaz dans de tels silencieux en augmentant au maximum le volume dans lequel débouchent lesdits gaz.The object of the present invention is to optimize the expansion of gases in such silencers by maximizing the volume into which said gases open.

A cette fin, selon l'invention, le silencieux du type décrit ci-dessus est caractérisé en ce que l'extrémité de la tubulure d'admission des gaz débouche dans ladite enveloppe allongée au niveau dudit orifice d'entrée ménagé dans ladite enveloppe.To this end, according to the invention, the silencer of the type described above is characterized in that the end of the gas intake manifold opens into said elongated casing at the level of said inlet orifice formed in said casing.

L'extrémité de ladite virole située dans la chambre tournée vers l'orifice d'entrée peut présenter une forme conique ou analogue. De même, l'extrémité de ladite virole située dans la chambre tournée vers l'orifice de sortie peut présenter un forme conique ou analogue.The end of said ferrule located in the chamber facing the inlet orifice may have a conical shape or the like. Similarly, the end of said ferrule located in the chamber facing the outlet orifice may have a conical shape or the like.

Selon un mode préféré de réalisation, l'enveloppe, la virole et la tubulure sont de forme de révolution et sont coaxiales entre elles.According to a preferred embodiment, the envelope, the ferrule and the tubing are of the shape of revolution and are coaxial with one another.

Avantageusement, la cloison transversale, séparant la virole en deux chambres adjacentes, est disposée dans un plan perpendiculaire à l'axe de ladite virole. Les deux chambres peuvent avoir un volume identique. Dans le but d'éliminer certaines fréquences, la virole comporte, au moins dans la première chambre tournée vers l'orifice d'entrée des gaz, une pluralité de perforations radiales.Advantageously, the transverse partition, dividing the shell into two adjacent chambers, is arranged in a plane perpendicular to the axis of said shell. The two rooms can have an identical volume. In order to eliminate certain frequencies, the ferrule comprises, at least in the first chamber facing the gas inlet orifice, a plurality of radial perforations.

Diverses variantes de réalisation présentent également des avantages au niveau de l'efficacité acoustique. Par exemple, un revêtement fibreux peut être agencé au moins dans la chambre de ladite virole tournée vers l'orifice d'entrée des gaz. Les extrémités de ladite virole peuvent également présenter une forme conique ou analogue. Aussi, l'axe de la virole peut être excentré par rapport à l'axe de l'enveloppe.Various variant embodiments also have advantages in terms of acoustic efficiency. For example, a fibrous coating can be arranged at least in the chamber of said shell facing the gas inlet orifice. The ends of said ferrule may also have a conical or similar shape. Also, the axis of the ferrule can be offset from the axis of the envelope.

Les figures du dessin annexé feront bien comprendre comment l'invention peut être réalisée. Des références identiques désignent des éléments semblables.

  • La figure 1 représente schématiquement un système d'échappement comportant le silencieux de l'invention adapté par exemple à un moteur thermique.
  • La figure 2 représente un coupe de silencieux selon un mode préféré de réalisation.
  • Les figures 3, 4 et 5 représentent, également en coupe, des variantes de réalisation dudit silencieux.
The figures of the appended drawing will make it clear how the invention can be implemented. Identical references designate similar elements.
  • FIG. 1 schematically represents an exhaust system comprising the silencer of the invention suitable for example for a heat engine.
  • FIG. 2 represents a section of muffler according to a preferred embodiment.
  • Figures 3, 4 and 5 show, also in section, alternative embodiments of said silencer.

On a représenté, sur la figure 1, un moteur thermique 1 du type à combustion interne, sur lequel est raccordé un pot d'échappement 2 constitué principalement d'un collecteur 3 raccordé sur les orifices d'échappement du moteur, d'un silencieux 4 et d'une tubulure d'échappement 5. Le passage du courant gazeux issu du moteur 1 s'effectue au travers des divers éléments mentionnés du pot d'échappement 2.There is shown in Figure 1, a heat engine 1 of the internal combustion type, to which is connected an exhaust 2 consisting mainly of a manifold 3 connected to the exhaust ports of the engine, a silencer 4 and an exhaust manifold 5. The passage of the gas stream from the engine 1 takes place through the various elements mentioned in the exhaust pipe 2.

En regard de la figure 2, le silencieux 4 pour courant gazeux selon l'invention, comprend une enveloppe 7, de forme sensiblement allongée, pourvue d'un orifice 8 d'entrée des gaz à une extrémité 9 de l'enveloppe et d'un orifice 10 de sortie des gaz à l'autre extrémité 11 de l'enveloppe.With reference to FIG. 2, the silencer 4 for the gas stream according to the invention comprises a casing 7, of substantially elongated shape, provided with an orifice 8 for the entry of gases at a end 9 of the casing and a gas outlet orifice 10 at the other end 11 of the casing.

L'orifice 8 d'entrée des gaz reçoit une extrémité 12 de la tubulure du collecteur 3 et l'orifice 10 de sortie des gaz reçoit une extrémité 15 de la tubulure d'échappement 5. Le courant gazeux circulant dans le silencieux 4 est représenté symboliquement par des flèches 16.The gas inlet port 8 receives one end 12 of the manifold manifold 3 and the gas outlet port 10 receives one end 15 of the exhaust manifold 5. The gas stream flowing in the silencer 4 is shown symbolically by arrows 16.

A l'intérieur de l'enveloppe 7 sont disposés les moyens de détente des gaz de l'invention.Inside the envelope 7 are arranged the means for expanding the gases of the invention.

Selon l'invention, ces moyens de détente sont constitués d'une part, par une virole 18 maintenue contre la paroi interne 19 de l'enveloppe 7 grâce à des pattes de fixation 20 et d'autre part, par l'extrémité 15 de la tubulure d'échappement 5.According to the invention, these expansion means consist on the one hand, by a ferrule 18 held against the internal wall 19 of the casing 7 by means of fixing lugs 20 and on the other hand, by the end 15 of the exhaust manifold 5.

Plus précisément, la virole 18 comprend une cloison transversale 23 qui partage le volume intérieur de cette virole en deux chambres 24 et 25 adjacentes.More specifically, the ferrule 18 comprises a transverse partition 23 which divides the interior volume of this ferrule into two adjacent chambers 24 and 25.

La chambre 24 est un regard de l'orifice 8 d'entrée des gaz tandis que la chambre 25 est en regard de l'orifice 10 de sortie des gaz. Un passage de communication 27 est ménagé entre la paroi extérieure 28 de la virole 18 et la paroi intérieure 19 de l'enveloppe 7 permettant ainsi le transfert et l'évacuation des gaz de la chambre 24 recevant les gaz en provenance du collecteur, à la chambre 25 en communication avec la tubulure de sortie des gaz.The chamber 24 is a view of the gas inlet orifice 8 while the chamber 25 is opposite the gas outlet orifice 10. A communication passage 27 is formed between the outer wall 28 of the shell 18 and the inner wall 19 of the casing 7 thus allowing the transfer and evacuation of the gases from the chamber 24 receiving the gases from the manifold, at the chamber 25 in communication with the gas outlet pipe.

Avantageusement, la longueur L de la virole 18 s'étend sur la majeure partie de la longueur L1 de l'enveloppe 7.Advantageously, the length L of the ferrule 18 extends over most of the length L1 of the casing 7.

Dans ce mode de réalisation de l'invention, la virole 18 et l'enveloppe 7 sont de forme de révolution et sont coaxiales autour d'un axe 30. De même, l'extrémité 12 du collecteur et l'extrémité 15 de la tubulure d'échappement 5 sont coaxiales à cet axe 30.In this embodiment of the invention, the ferrule 18 and the casing 7 are of the shape of revolution and are coaxial around an axis 30. Similarly, the end 12 of the manifold and the end 15 of the tubing exhaust 5 are coaxial with this axis 30.

Les deux chambres 24 et 25 de la virole 18, délimitées par la cloison transversale 23 agencée perpendiculairement par rapport à l'axe 30 commun à la virole et à l'enveloppe, ont un volume identique.The two chambers 24 and 25 of the shell 18, delimited by the transverse partition 23 arranged perpendicularly to the axis 30 common to the shell and to the envelope, have an identical volume.

La virole 18 comporte également dans la première chambre 24, des perforations radiales 31 qui ont pour but de réduire des fréquences propres dues au couplage des deux chambres adjacentes.The ferrule 18 also comprises in the first chamber 24, radial perforations 31 which have the purpose of reducing natural frequencies due to the coupling of the two adjacent chambers.

Les moyens de détente selon l'invention sont constitués également par l'extrémité 15 de la tubulure d'échappement 5 agencée en saillie dans la chambre 25 de la virole de façon que la face 34 de ladite extrémite 15 soit en regard de la cloison 23. L'agencement de l'extrémité 15 dans la chambre 25 présente alors une impédance supplémentaire à l'encontre des gaz avant leur éjection dans l'atmosphère.The expansion means according to the invention also consist of the end 15 of the exhaust pipe 5 arranged projecting in the chamber 25 of the shell so that the face 34 of said end 15 is opposite the partition 23 The arrangement of the end 15 in the chamber 25 then has an additional impedance against the gases before their ejection into the atmosphere.

Le fonctionnement du silencieux fera apparaître très nettement les avantages qu'il procure.The operation of the silencer will clearly show the advantages it provides.

Les gaz 16 issus du collecteur à une pression acoustique et température importants débouchent dans la chambre 24 où ils subissent une détente.The gases 16 coming from the manifold at a high acoustic pressure and temperature open into the chamber 24 where they undergo expansion.

Les gaz ressortent de la première chambre 24 de la virole 18 et se dirigent dans le passage annulaire 27 où ils circulent avec une vitesse élevée.The gases emerge from the first chamber 24 of the ferrule 18 and go into the annular passage 27 where they circulate with a high speed.

Une faible partie des gaz traverse également les perforations radiales 31 pratiquées dans la première chambre 24 de la virole.A small part of the gases also passes through the radial perforations 31 formed in the first chamber 24 of the shell.

Les pertes acoustiques sont d'autant plus importantes, pour une section de passage 27 donnée, que la longueur de ce passage 27 est importante.The acoustic losses are all the more important, for a given passage section 27, the greater the length of this passage 27.

Cet objectif est atteint par l'invention grâce à la longueur de la virole L qui est la plus proche possible de la longueur de l'enveloppe L1.This objective is achieved by the invention thanks to the length of the shell L which is as close as possible to the length of the envelope L1.

Les gaz 16 se propagent alors vers la cloison 23, puis s'orientent vers la tubulure d'échappement 5, où ils s'engouffrent jusqu'à leur éjection dans l'atmosphère. Le niveau acoustique atteint par les gaz étant encore abaissé grâce à l'extrémité 15 agencée en saillie dans la seconde chambre 25 puisque l'extrémité 15 augmente l'impédance de sortie des gaz.The gases 16 then propagate towards the partition 23, then orient themselves towards the exhaust pipe 5, where they rush in until they are ejected into the atmosphere. The acoustic level reached by the gases being further lowered by virtue of the end 15 protruding in the second chamber 25 since the end 15 increases the gas output impedance.

Le niveau sonore obtenu à la sortie de la tubulure d'échappement procure alors des résultats particulièrement satisfaisants. Le silencieux de l'invention basé sur le couplage acoustique entre deux chambres définies par la virole, permet d'obtenir une atténuation acoustique du bruit importante.The noise level obtained at the outlet of the exhaust manifold then gives particularly satisfactory results. The silencer of the invention based on the acoustic coupling between two chambers defined by the shell, makes it possible to obtain a significant acoustic attenuation of the noise.

Les diverses réalisations, ci-dessous décrites, présentent des améliorations au niveau de l'efficacité acoustique du silencieux.The various embodiments, described below, present improvements in the acoustic efficiency of the silencer.

L'explication de l'atténuation de ce silencieux peut être résumée par le fait que la fonction de transfert de celui-ci est celle d'un filtre passe-bas à deux degrés de liberté, c'est-à-dire que toutes les fréquences situées au-dessus de sa frequence de coupure sont fortement atténuées et que les fréquences situées au-dessous le sont faiblement.The explanation for the attenuation of this silencer can be summarized by the fact that its transfer function is that of a low-pass filter with two degrees of freedom, that is to say that all frequencies above its cutoff frequency are strongly attenuated and the frequencies below it are weakly attenuated.

Il est donc nécessaire de placer la plus basse fréquence à atténuer au-dessus de cette fréquence de coupure.It is therefore necessary to place the lowest frequency to be attenuated above this cutoff frequency.

La figure 3 illustre une variante de réalisation pour laquelle les extrémités 35 et 36 de la virole 18 ont été modifiées. Elles se perésentent sous une forme conique.FIG. 3 illustrates an alternative embodiment for which the ends 35 and 36 of the shell 18 have been modified. They are presented in a conical shape.

Grâce à ces extrémités coniques 35 et 36, les pertes de charge des gaz sont moins importantes et l'efficacité acoustique du silencieux est accrue.Thanks to these conical ends 35 and 36, the gas pressure drops are less and the acoustic efficiency of the silencer is increased.

La figure 4 illustre un ature variante de réalisation pour laquelle la chambre 24 tournée vers l'orifice 8 d'entrée du gaz est recouverte d'un revêtement fibreux 40 tel qu'un matelas de laine minérale. Un carter métallique 41, percé d'orifices 42, maintient le revêtement fibreux 40 contre la virole 18 et la cloison 23. Ce traitement favorise l'amortissement des fréquences propres.Figure 4 illustrates an alternative embodiment ature for which the chamber 24 facing the orifice 8 of the gas inlet is covered with a fibrous coating 40 such as a mineral wool mattress. A metal casing 41, pierced with orifices 42, maintains the fibrous coating 40 against the shell 18 and the partition 23. This treatment promotes the damping of the natural frequencies.

La figure 5 illustre une variante de réalisation, qui consiste à excentrer la virole 18 de l'enveloppe 7. La virole est solidaire de l'enveloppe au moyen, par exemple, d'une soudure. Ainsi, le nouvel axe géométrique 45 de la virole 18 est décalé par rapport à l'axe 30 de l'enveloppe.FIG. 5 illustrates an alternative embodiment, which consists in off-centering the shell 18 of the envelope 7. The shell is integral with the envelope by means, for example, of a weld. Thus, the new geometric axis 45 of the shell 18 is offset with respect to the axis 30 of the envelope.

Le fonctionnement du silencieux en regard de ces diverses variantes de réalisation est similaire à celui précédemment décrit en regard de la figure 2.The operation of the silencer with regard to these various embodiments is similar to that previously described with regard to FIG. 2.

Les applications d'un tel silencieux concernent les moteurs à combustion interne de tous types (essence, diesel, gaz), les turbines à gaz, les compresseurs, etc ...The applications of such a silencer relate to internal combustion engines of all types (petrol, diesel, gas), gas turbines, compressors, etc.

Claims (8)

1. Gaseous flow silencer of the type comprising:
an elongated envelope (7) to the ends (9 and 11) of which are provided, respectively, an inlet orifice (8) which is connected to a gas inlet pipe (3), and, an outlet orifice (10) which is connected to a gas exhaust pipe (5); and
means for expanding said gas, disposed inside said envelope (7) and constituted by a sleeve (18) comprising a transversal wall (23) separating it into two chambers (24, 25), the one (24) directed toward said inlet orifice (8) of said envelope and the other (25) directed toward said outlet orifice (10) of said envelope, said sleeve (18) providing a passage (27) with the inner surface (19) of said envelope (7) and extending on the greater part of the length of said envelope, characterized in that the end (12) of the gas inlet pipe (3) emerges in said elongated envelope (7) at the level of said inlet orifice (8) provided in said envelope.
2. Silencer according to claim 1, characterized in that the end (35) of the sleeve (18) located in the chamber (24) directed toward the inlet orifice (8) presents a conical shape or the like.
3. Silencer according to any one of claims 1 or 2, characterized in that the end (36) of the sleeve (18) located in the chamber (25) directed toward the outlet orifice (10) presents a conical shape or the like.
4. Silencer according to any one of claims 1 to 3, characterized in that said envelope (7) and said sleeve (18) and pipe (5) present a revolution shape and are coaxial to each other.
5. Silencer according to any one of claims 1 to 4, characterized in that said transversal wall (23) separating said sleeve into two adjacent chambers (24, 25) is disposed in a plane perpendicular to the axis (30) of said sleeve.
6. Silencer according to any one of claims 1 to 5, characterized in that said sleeve (18) comprises, at least in the first chamber (24) directed toward the inlet orifice, a plurality of radial perforations (31).
7. Silencer according to any one of claims 1 to 6, characterized in that a fibrous coating (40) is disposed at least in the chamber (24) of said sleeve.
8. Silencer according to any one of claims 1 to 7, characterized in that both chambers (24, 25) of said sleeve have the same volume.
EP86401886A 1986-04-30 1986-08-27 Gas flow silencer Expired - Lifetime EP0243559B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86401886T ATE54721T1 (en) 1986-04-30 1986-08-27 SILENCER FOR GAS FLOW.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8606304 1986-04-30
FR8606304A FR2598176B1 (en) 1986-04-30 1986-04-30 SILENCER FOR GAS CURRENT

Publications (2)

Publication Number Publication Date
EP0243559A1 EP0243559A1 (en) 1987-11-04
EP0243559B1 true EP0243559B1 (en) 1990-07-18

Family

ID=9334808

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86401886A Expired - Lifetime EP0243559B1 (en) 1986-04-30 1986-08-27 Gas flow silencer

Country Status (5)

Country Link
EP (1) EP0243559B1 (en)
AT (1) ATE54721T1 (en)
DE (1) DE3672829D1 (en)
ES (1) ES2002833A6 (en)
FR (1) FR2598176B1 (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CS271879B1 (en) * 1988-08-16 1990-12-13 Jaroslav Cervinka Exhaust silencer for internal combustion engines
DE3832030A1 (en) * 1988-09-21 1990-03-29 Wabco Westinghouse Fahrzeug SOUND ABSORBER
FR2713702B1 (en) * 1993-12-14 1996-03-01 Boet Sa Andre Muffler for gas flow.
FR2713701B1 (en) * 1993-12-14 1996-03-01 Boet Sa Andre Muffler for gas flow.
DE10303947A1 (en) * 2003-01-31 2004-08-19 J. Eberspächer GmbH & Co. KG Muffler for a heater, especially a vehicle heater
DE102010008403A1 (en) * 2010-02-18 2011-08-18 J. Eberspächer GmbH & Co. KG, 73730 silencer
GB2479787A (en) * 2010-04-23 2011-10-26 Exhausts Uk Ltd Exhaust silencer with acoustic reducer cup
DE102017107601B4 (en) 2017-04-10 2019-11-07 Gardner Denver Deutschland Gmbh Method for controlling a screw compressor
DE102017107599A1 (en) * 2017-04-10 2018-10-11 Gardner Denver Deutschland Gmbh Pulsation silencer for compressors
DE102017107602B3 (en) 2017-04-10 2018-09-20 Gardner Denver Deutschland Gmbh Compressor system with internal air-water cooling
CN108926266B (en) * 2017-05-27 2021-10-26 广东美的生活电器制造有限公司 Amortization lid, bowl cover subassembly and food processor
US11391195B2 (en) * 2019-06-19 2022-07-19 Tenneco Automotive Operating Company Inc. Exhaust system and muffler

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE513629A (en) *
DE918062C (en) * 1948-12-31 1954-09-16 Leistritz Maschfabrik Paul Silencer with successive chambers
FR1226438A (en) * 1958-10-09 1960-07-11 Silencer for the flow of fluids
US3651888A (en) * 1970-07-24 1972-03-28 Tenneco Inc Multi-pass muffler
US4220219A (en) * 1978-09-14 1980-09-02 Flugger Ray T Lightweight muffler and method for muffling noise

Also Published As

Publication number Publication date
FR2598176A1 (en) 1987-11-06
ES2002833A6 (en) 1988-10-01
DE3672829D1 (en) 1990-08-23
ATE54721T1 (en) 1990-08-15
EP0243559A1 (en) 1987-11-04
FR2598176B1 (en) 1990-01-19

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