EP1553284B1 - Air intake silencing device especially for turbocharged engines or air conditioner and intake circuit with such a device - Google Patents

Abstract

The device has a pipe section (1) formed by two semi-shells (3, 4) partitioned with longitudinal partition walls extending from a bottom wall to a sealing surface of the respective semi-shells. The partition walls contact at their free edges (12). Each edge has notches (14) constituting, in the assembled state of the semi-shells, an opening for communication between a resonance chamber and a main pipe section (5). An independent claim is also included for an air inlet circuit of an internal combustion engine or an air conditioning device equipped with a noise reduction device.

Description

The present invention relates to a device for attenuating noise on an air intake circuit for an internal combustion engine, preferably supercharged, or apparatus for air conditioning, and an air intake circuit for an engine, preferably supercharged, or air conditioning apparatus, equipped with such a device for attenuation of noise.

It relates more particularly to a noise attenuation device in the form of a pipe section integrable by each of its ends respectively constituting an inlet and an air outlet to the air intake circuit, this section of pipe , formed by the assembly of two half-shells, being partitioned longitudinally to delimit, along an axial air passage connecting the air inlet and the air outlet and called the main duct section, at least a blind volume consisting of a resonance chamber communicating via at least one opening with said main duct section to establish an air communication between the resonance chamber and the main duct section. such a device is described in the document JP-2002-138915 .

Such a noise attenuation device is more particularly intended to be positioned on the supercharged portion of an air intake circuit for an internal combustion engine. Indeed, to increase the power of the engines, we use today a turbocharger. This increases the air supply pressure but also the temperature. It is therefore necessary, as illustrated by figure 1 relating to the state of the art, that the air passes through a cooler A fixed on the vehicle before reaching the engine. In many cases, the line connecting the turbocharger B and the air cooler A is composed of two parts, namely a flexible portion C rubber or silicone adapted to absorb the movements of the engine / body and a rigid portion D plastic or metal to minimize the cost and mass of all.

A second problem, related to the hissing of the turbocharger A, intervenes on this conduct. Indeed, the turbocharger A generates a whistling whose frequency is proportional to the speed of rotation of the turbine. This acoustic wave will propagate in the pipe and radiate through the flexible part C. In order to mitigate these noises, the solution adopted so far is to implement a damper E as close as possible to the turbocharger B as shown in FIG. figure 1 . This constitutes an additional piece, therefore a cost as well as an additional connection. We are therefore looking today for a noise attenuation device having a size and rigidity characteristics for its integration, especially in this part of the air intake circuit.

A large number of noise attenuation devices are known through the state of the art. Thus, an example of a noise attenuation device is described in particular in the JP-2002 Patent 138915 . This noise attenuation device is formed of two elements which, in the assembled state, form a double-walled cylinder. The two parts of this cylinder are obtained by cutting the cylinder along its median diametral plane. Each half-cylinder consists of two walls connected to each other by their edge to define a closed volume. This volume closed by an opening in each inner wall communicates with the axial pipe section formed in the assembled state of the two cylinder parts. The resonance chambers thus obtained are annular chambers. Because of the design of the attenuation device, these annular chambers are at most two in number. As a result, the system obtained is an extremely rigid system where it becomes very difficult to vary the frequency setting of the resonance chambers obtained and the general shape of the conduit.

We also know, through the patent JP-2004 011604 , an air cleaning device intended more particularly to be positioned between the mouth or external air intake of the air intake circuit and the filter box on the part of the air intake circuit in which the air flowing is an air generally charged with impurities. This device is not intended to reduce noise. It is simply not to increase the sound level. This device is again constituted by the assembly of two half-shells. Each half-shell is provided with partitions which define an axial duct connecting an inlet and an air outlet, these partitions being interrupted over their entire height to define a single opening of communication between the impurity recovery chambers and the axial duct, these chambers being made asymmetrical. In view of the purpose of this device, this device must be considered as belonging to the technical background. In addition, because the opening is obtained by an interruption of the partition, this opening can vary in size only in its width. As a result, the possibilities of modifications of the opening are limited. Moreover, this design is such that it is possible to integrate, in such a device, only two asymmetrical chambers.

An object of the present invention is therefore to provide a noise attenuation device on an air intake circuit whose design allows attenuation of noise in a wide frequency band while having a small footprint.

Another object of the present invention is to propose a device for attenuating noise on an air intake circuit whose design makes it possible to have an acoustic attenuator incorporated in a rigid part of pipe in order to minimize the number of components.

Another object of the present invention is to provide a noise attenuation device on an air intake circuit whose design makes it possible to adapt to complex driving profiles.

Another object of the present invention is to provide a noise attenuation device on an air intake circuit whose design allows to make easily varying the openings for communicating the resonance chambers with the main pipe section by varying the height, width, shape and position of the openings on said conduit so as to vary will frequency setting resonators thus formed.

For this purpose, the subject of the invention is a device for attenuating noise on an air intake circuit for an internal combustion engine, preferably supercharged, or an apparatus for air conditioning, these noises being in particular derived from the turbocharger and / or the engine and / or the vehicle air conditioning unit, this noise attenuation device being in the form of a section of pipe integrable by each of its ends respectively constituting an inlet and an air outlet to the circuit air intake, this section of pipe, resulting from the assembly of two half-shells, being partitioned longitudinally to delimit, along an axial air passage connecting the air inlet and the outlet of and called main conduit section, at least one blind volume consisting of a resonance chamber communicating via at least one opening with said main duct section to establish a communication of a ir between the resonance chamber and the main duct section, characterized in that each half-shell of the duct section is partitioned by means of at least one longitudinal partition originating on the bottom wall of the half-shell. shell and extending with its free edge into the joint plane of the half-shells, said partitions coming into point contact point by their free edge in the assembled state of the half-shells, each partition being provided on its edge free of notches constituting, in the assembled state of the half-shells, the communication opening between the resonance chamber and the main duct section.

Thanks to the design of the attenuation device, it is possible to integrate such a device on any type of circuit, including circuits with a complex profile. In addition, such a noise attenuation device makes it possible to simultaneously perform the rigid duct air circulation and acoustic attenuation function by means of a single element whose profile can be any. This objective could not be fulfilled with conventional noise attenuation devices with annular chambers.

Finally, the design of such a device makes it possible to adapt to any type of request in terms of acoustic attenuation, the modification of the resonance chambers and their opening of communication with the main duct section being easy to realize to enable the adjustment at will of the frequencies of the resonators thus formed.

The subject of the invention is also an air intake circuit for an engine, preferably a supercharged engine, or an air conditioning apparatus, of the type equipped with a device for attenuation of the noises, these noises being in particular stemming from the operation of the turbocompressor and or the engine and / or the vehicle air conditioning unit, this noise attenuation device being in the form of a section of pipe integrable by each of its ends constituting an inlet and an air outlet to the circuit air intake, this section of pipe, resulting from the assembly of two half-shells, being partitioned longitudinally to delimit, along an axial air passage connecting the air inlet and the outlet of and called a main duct section, at least one blind volume consisting of a resonance chamber communicating via at least one opening with said main duct section for establishing an air communication between the resonance chamber and the main duct section, characterized in that the noise attenuation device of the air intake circuit is of the aforementioned type.

• la figure 1 représente l'état de la technique ;
• la figure 2 représente une vue schématique de la portion du circuit d'admission d'air entre un turbocompresseur et un refroidisseur sur lequel est intégré un dispositif d'atténuation des bruits conforme à l'invention ;
• la figure 3 représente une vue en perspective des deux demi-coquilles constitutives du dispositif d'atténuation des bruits à l'état non assemblé des deux demi-coquilles ;
• la figure 4 représente une vue en coupe du dispositif d'atténuation des bruits à l'état assemblé des demi-coquilles et
• la figure 5 représente une vue en perspective d'une seule demi-coquille.

The invention will be better understood on reading the following description of exemplary embodiments, with reference to the appended drawings in which:

• the figure 1 represents the state of the art;
• the figure 2 represents a schematic view of the portion of the air intake circuit between a turbocharger and a cooler on which is integrated a noise attenuation device according to the invention;
• the figure 3 represents a perspective view of the two half-shells constituting the unassembled noise attenuation device of the two half-shells;
• the figure 4 represents a sectional view of the noise attenuation device in the assembled state of the half-shells and
• the figure 5 represents a perspective view of a single half-shell.

As mentioned above, the noise attenuation device, object of the invention, is intended to be installed on an air intake circuit for an internal combustion engine, preferably supercharged, or on a circuit of air intake for an air conditioning unit. Indeed, the noises to be attenuated are in particular those from the turbocharger 2 and / or the engine and / or the air conditioning device of the vehicle. In the examples shown, the noise attenuation device is disposed in the area of the air intake circuit extending between the turbocharger 2 and a cooler 3 adapted to cool the air from the turbocharger 2. This preferred arrangement allows to combine in a single element noise attenuation functions and rigid air circulation pipe which, until now, were made in the form of two differentiated elements.

This noise attenuation device is in the form of a section 1 of pipe integrable by each of its ends to the air intake circuit. One end of the pipe section 1 is an air inlet 2A while the other end is an air outlet 2B. In the examples shown, the pipe section 1 has at each of its ends a section of reduced size to form a connection end solidarisable to the rest of the air intake circuit, preferably by sealing. Thus, the connection ends, formed in one piece with the section 1 of pipe, extend at each end of the section 1 of driving beyond the shoulder formed by the narrowing of the section. This pipe section 1 is formed by the assembly of two half-shells shown at 3 and 4 in the figures. This pipe section 1 is partitioned longitudinally to define, along an axial air passage connecting the air inlet 2A and the outlet 2B of the pipe section 1, at least one blind volume consisting of a chamber 6 of resonance. This axial air passage is called the main duct section. This axial passageway can thus communicate, via at least one opening 7, with the blind volume constituting the resonance chamber 6 to establish an air communication between the resonance chamber 6 and the main duct section 5. . Characteristically to the invention, each half-shell 3, 4 of the pipe section 1 is partitioned using at least one longitudinal partition 8, 9. This partition, shown at 8 for the half-shell 3 and 9 for the half-shell 4, came from molding with the half-shell. It originates on the bottom wall of the half-shell and extends with its free edge 12 at least as far as the joint plane 13 of the half-shells 3, 4. The partitions 8 or 9 thus come into contact with each other. point support by their free edge 12 in the assembled state of the half-shells 3, 4. Each partition 8, 9 is provided on its free edge with notches 14 constituting, in the assembled state of the half-shells 3 and 4, the communication opening 7 between resonance chamber 6 and main section 5 of conduit. The bottom of the half-shell can affect a lot of shapes. In the examples shown, the bottom of the half-shell consists, seen in cross-section, of a concave portion corresponding to the zone serving to delimit the portion of the main section of conduit adjoined on each side by two bulges constituting the bottom portion of the chamber 6 delimited by means of said half-shell. Of course, other room profiles could have been adopted including a more regular scalloped profile. The realization of the bottom wall of each half-shell in the form of a multi-lobed wall makes it possible to increase the volume of the resonance chambers.

To allow attenuation of the noises produced in a broad band of frequencies, the resonance volume delimited by the partitions 8, 9 longitudinals opposite the half-shells 3, 4 is compartmentalized through transverse walls 10, 11 integrally molded with each half-shell 3, 4. These transverse walls, shown at 10 for the half-shell 3 and 11 for the half-shell 4, extend, with their free edge 15, at least as far as in the joint plane of the half-shells. These transverse walls thus come by their free edge in bearing contact in the assembled state of the half-shells 3, 4 so as to delimit along the main section 5 of conduct a plurality of chambers 6 aligned Helmholtz resonator type allowing broadband attenuation of noise.

In the examples shown, each half-shell 3, or respectively 4, has two parallel longitudinal walls 8 or 9 arranged on either side of the main driving section so as to present two series of chambers 6 of FIG. resonance with the same or different acoustic characteristics. These resonance chambers 6 can thus have an increasing volume from the air inlet 2A towards the air outlet 2B of said pipe section 1. The spacing between the transverse walls 10 or respectively 11, on the one hand, the shape and the dimensions of the notches 14 of the longitudinal wall 8 or respectively 9 are chosen according to the frequency range of the noise to be attenuated . In the examples shown, the transverse partition walls 10 and 11 of the half-shells 3, 4 are respectively connected to the longitudinal wall 8, 9 of said half-shell 3, 4, in the zone of said longitudinal wall 8, 9 extending between two notches 14, so as to form as many chambers 6 as notches 14. Thus, in the example shown, the noise attenuation device comprises, on either side of the main section 5 of conduct, each time a series of five chambers, a total of ten sounding chambers. Each chamber of a series of chambers is dimensioned differently, the chambers being identical from one series to another because the half-shells are, for reasons of simplification of manufacture, made identical. The two series of chambers are made symmetrical with respect to the median longitudinal plane of the driving section.

The assembly of the half-shells between them is obtained thanks to the fact that each half-shell has along its longitudinal edges a flange whose outer face is intended to come into bearing contact with the outer face of the rim of the corresponding half-shell to form a joint plane 13 of the half-shells in the assembled state. During this assembly of the half-shells between them, the edges 12, 15 free in bearing contact of the longitudinal walls 8, 9 and transverse 10, 11 are joined to each other sealingly, preferably welded . Thus, the delimited chambers 6 do not communicate with each other. It could also have been provided in a similar manner to make notches in the transverse walls 10, 11 so as to ensure communication between the resonance chambers 6.

It is noted that, in the examples shown, the section reduction at each of the ends of the pipe section 1 to delimit connection ends securable to the rest of the air intake circuit allows to delimit a shoulder zone. The longitudinal walls 8, 9 for partitioning extend in the widened section portion of the pipe section 1 to the right of said shoulder.

Claims (11)

1. A device for attenuating noises on an air admission circuit for an internal combustion preferably turbocharged engine, or an air-conditioning apparatus, these noises notably stemming from the turbocompressor (2) and/or from the engine and/or from the air-conditioning apparatus of the vehicle, this device for attenuating noises appearing as a conduit section (1) integrable by each of its ends, respectively forming an inlet (2A) and an outlet (2B) for the air admission circuit, this conduit section(1) stemming from the assembly of two half-shells (3,4), being partitioned longitudinally in order to delimit along an axial air passage connecting the air inlet (2A) and the air outlet (2B) and called a main conduit section (5), at least one blind volume consisting of a resonance chamber (6) communicating via at least one aperture (7) with said main conduit section (5) in order to establish air communication between the resonance chamber (6) and the main conduit section (5),
   characterized in that each half-shell (3,4) of the conduit section(1) is partitioned with at least one longitudinal partition (8,9) originating on the bottom wall of the half-shells (3, 4) and extending with its free edge (12) right into the gasket plane (13) of the half-shells (3, 4), said partition (8, 9) coming into point-like supporting contact by their free edge (12) in the assembled condition of the half-shells (3,4), each partition (8,9) being provided on its free end with notches (14) forming, in the assembled condition of the half-shells (3,4), the communication aperture (7) between the resonance chamber (6) and the main conduit section (5).
2. The device for attenuating noises according to claim 1,
   characterized in that the resonance volume delimited by the longitudinal partitions (8, 9) facing the half-shells (3; 4) is divided into compartments via transverse walls (10, 11) made with each half-shell (8, 9) by molding, these transverse rows (10, 11) which extend, with their free edge, at least right into the gasket plane of the half-shells coming into supporting contact with their free edge in the assembled condition of the half-shells (3, 4) so as to delimit along the main conduit section (5) a plurality of aligned chambers (6) of the Helmholtz resonator type allowing wide band attenuation of the noises.
3. The device for attenuating noises according to claim 2,
   characterized in that the transverse partitioning walls (10, 11) of each half-shell (3, 4) are connected to the longitudinal wall (8, 9), of said half-shell (3, 4), in the area of said longitudinal wall (8, 9) extending between two notches (14), so as to form as many chambers (6) as there are notches (14).
4. The device for attenuating noises according to claim 2,
   characterized in that the free edges (12, 15) in contact and bearing upon the longitudinal (8, 9) and transverse (10, 11) walls are sealably assembled with each other, preferably welded during the assembling of the half-shells (3, 4) together.
5. The device for attenuating noises according to claims 2 to 4,
   characterized in that the resonance chambers (6) have a volume which increases from the air inlet (2A) to the air outlet (2B) of said conduit section (1).
6. The device for attenuating noises according to claims 2 to 5,
   characterized in that the gap between the transverse walls (10, 11) on the one hand, the shape and dimensions of the notches (14) of the longitudinal walls (8, 9) on the other hand are selected depending on the frequency range of the noise to be attenuated.
7. The device for attenuating noises according to claims 1 to 6, characterized in that the half-shells (3, 4) are identical.
8. The device for attenuating noises according to claims 1 to 7,
   characterized in that each half-shell (3, 4) includes two parallel longitudinal walls (8, 9) positioned on either side of the main conduit section (5) so as to have two resonance chamber (6) series with identical or different acoustic characteristics.
9. The device for attenuating noises according to claims 1 to 8,
   characterized in that the conduit section (1) has at each of its ends a section of reduced size in order to form a connecting endpiece which may be firmly attached to the remainder of the air admission circuit, preferably by leak-proof welding.
10. An air admission circuit for a preferably overcharged engine or an air-conditioning apparatus, of the type equipped with a device for attenuating noises, these noises notably stemming from the operation of the turbocompressor (2) and/or of the engine and/or air-conditioning apparatus of the vehicle, this device for attenuating noises appearing as a conduit section (1) integrable by each of its ends forming an air inlet (2A) and an air outlet (2B) for the air admission circuit, this conduit section (1) stemming from the assembly of both half-shells (3, 4), being partitioned longitudinally in order to delimit a long and axial air passage connecting the air inlet (2A) and the air outlet (2B) and called the main conduit section (5), at least one blind volume consisting of a resonance chamber (6) communicating via at least one aperture (7) with said main conduit section in order to establish air communication between the resonance chamber (6) and the main conduit section (5), characterized in that the device for attenuating noises of the air admission circuit is in accordance with any of claims 1 to 9.
11. The air admission circuit according to claim 10,
    characterized in that the device for attenuating the noises is positioned in the area of the air admission circuit between the turbo-compressor (2) and a cooler (3) capable of cooling the air from the turbocompressor (2).

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