EP2801708B1 - Sound Generator for an Anti-noise System for influencing exhaust Noises and/or intake Noises of a Motor Vehicle - Google Patents

Description

The invention relates to a sound generator for an anti-sound system for influencing sound waves conducted in exhaust systems of vehicles powered by internal combustion engines (exhaust noise) and / or for influencing sound waves conducted in intake systems of internal combustion engines (intake noise).

Regardless of the design of an internal combustion engine (for example reciprocating engine, rotary piston engine or free-piston engine) noises are generated as a result of the successive operating cycles (in particular suction and compression of a fuel-air mixture, working and expelling the combusted fuel-air mixture). These go through as a structure-borne noise the internal combustion engine and are radiated outside the internal combustion engine as airborne sound. On the other hand, the noise as airborne sound, together with the combusted fuel-air mixture, pass through an exhaust system in fluid communication with the internal combustion engine.

These sounds are often perceived as detrimental. On the one hand, there are legal requirements for noise protection that manufacturers of combustion engine-powered vehicles must comply with. These legal requirements usually specify a maximum permissible sound pressure during operation of the vehicle. On the other hand, manufacturers are trying to impose a characteristic noise development on the combustion engine-driven vehicles they produce, which matches the image of the respective manufacturer and should appeal to the customers. This characteristic noise development is often no longer natural in modern engines with low displacement to ensure.

The noise that passes through the internal combustion engine as structure-borne sound can be well insulated and therefore generally poses no problem with regard to noise protection.

The an exhaust system of the internal combustion engine together with the combusted fuel-air mixture as airborne noise passing through are arranged in front of the mouth of the exhaust system arranged muffler, which are possibly downstream of existing catalysts. Such silencers can work, for example, according to the absorption and / or reflection principle. Both modes of operation have the disadvantage that they require a comparatively large volume and set a relatively high resistance to the burned fuel-air mixture, whereby the overall efficiency of the vehicle decreases and fuel consumption increases.

As an alternative or supplement to silencers so-called anti-noise systems have been developed for some time, which superimpose an electro-acoustically generated anti-sound generated by the internal combustion engine and conducted in the exhaust system airborne sound. Such systems are for example from the documents US 4,177,874 . US 5,229,556 . US 5,233,137 . US 5,343,533 . US 5,336,856 . US 5,432,857 . US 5,600,106 . US 5,619,020 . EP 0 373 188 . EP 0 674 097 . EP 0 755 045 . EP 0 916 817 . EP 1 055 804 . EP 1 627 996 . DE 197 51 596 . DE 10 2006 042 224 . DE 10 2008 018 085 and DE 10 2009 031 848 known.

Such antisound systems usually use a so-called filtered-mean-time squares (FxLMS) algorithm, which attempts the airborne sound carried in the exhaust system by outputting sound via at least one loudspeaker in fluid communication with the exhaust system Zero (in the case of sound cancellation) or a predetermined threshold (in the case of sound interference) to regulate. To achieve complete destructive interference of the sound waves of the airborne sound carried in the exhaust system and the anti-sounding generated by the loudspeaker, the sound waves originating from the loudspeaker must correspond in amplitude and frequency to the sound waves carried in the exhaust system, but have a phase shift of 180 degrees relative thereto , Although the sound waves of the airborne sound carried in the exhaust system and the sound waves of the anti-sounding generated by the loudspeaker are in frequency, and they have a phase shift of 180 degrees relative to one another, the sound waves do not correspond in amplitude but only to a weakening of the guided in the exhaust system sound waves of airborne sound. For each frequency band of the airborne sound carried in the exhaust pipe, the anti-noise is calculated separately by means of the FxLMS algorithm by determining an appropriate frequency and phase of two mutually shifted by 90 degrees sine waves, and the required amplitudes for these sine waves are calculated. The aim of anti-sound systems is that the sound cancellation or sound influencing at least outside, but possibly also within the exhaust system is audible and measurable. The term anti-noise is used in this document to distinguish the airborne sound carried in the exhaust system. By itself, Anti-Schall is ordinary airborne sound. It is emphasized that the present invention is not limited to the use of a FxLMS algorithm.

Also in the intake of internal combustion engines sound waves occur that can be distracting. These sound waves are caused by both turbulence in the air flow and by the internal combustion engine itself. The intake system, also called the intake system is referred to, includes all combustion air leading components of an internal combustion engine, which are located in front of the combustion chamber or the combustion chamber.

An antisound system for influencing sound waves guided in an exhaust system of a vehicle operated by an internal combustion engine is disclosed in the document EP 2 108 791 A1 previously known and will be described below with reference to Figures 1 and 2 described.

This in FIG. 1 shown in a schematic perspective view of the anti-sound system has a sound generator 3 in the form of a solid housing containing an electrodynamic speaker 2 and is connected via a Y-piece 1 to an exhaust system 4. The Y-piece 1 has at the foot of the "Y" on an orifice 5 to emit exhaust gas guided in the exhaust system 4 to the outside. Through the connection via the Y-piece, the thermal load of the recorded in the sound generator 3 speaker 2 is kept low by the guided in the exhaust system 4 exhaust gas. This is necessary because conventional speakers can only work in a range of up to 200 ° C, the temperature of the exhaust gas guided in the exhaust system 4 but can be up to between 400 ° C and 700 ° C.

In FIG. 2 schematically is a sectional view through the sound generator 3 using the example of a voice coil loudspeaker shown. As can be seen, the loudspeaker 2 has a permanent magnet 21 and a funnel-shaped membrane 22, which are jointly carried by a loudspeaker basket 23. In this case, the membrane 22 is radially outwardly connected via an elastic bead (not shown) to the loudspeaker frame 23 and has radially inside a voice coil (not shown), which is guided in bores in the permanent magnet 21. By applying an alternating current to the voice coil is via the voice coil due to the Lorentz force exerted a force on the diaphragm 22, which causes them to vibrate. The loudspeaker basket 23 is supported radially on the outside by a horn 42, which is connected to the Y-piece 1 via a connecting tube 41. The use of the bell mouth 42 is required because the area of the diaphragm 22 of the loudspeaker 2 is greater than the cross-sectional area of the exhaust system 4 in the region of the coupling of the sound. This is necessary to achieve the required sound fluxes.

In the structure described above, it is disadvantageous that the sound generator has a considerable volume of construction. Such is due to numerous restrictive space conditions in the underbody of a vehicle or in the intake system receiving engine compartment of a vehicle only limited available. Since significant noise flows are required in anti-noise systems for vehicles powered by internal combustion engines, it is also not possible to simply reduce the diameter of the loudspeaker. Rather, it is necessary that the area of the diaphragm of the loudspeaker is greater than or equal to the cross-sectional area of the exhaust system or the intake system in the coupling of the sound. This in turn requires the use of a bell tower as a transition between the diaphragm of the speaker and the connector to the exhaust system or intake.

Sound generators having the features of the preamble of independent claim 1 are known from the documents US 2005/152576 A1 . US 2005/152569 A1 and US 2010/322461 A1 known.

It is an object of the present invention to provide a sound generator for an anti-noise system for influencing exhaust noise or intake noise of internal combustion engine powered vehicles, which has a compact volume and yet provides a high flow of sound.

The above object is achieved by the combination of the features of independent claim 1. Preferred developments can be found in the subclaims.

Embodiments of a sound generator for an anti-noise system for influencing sound waves guided in exhaust systems or intake systems of vehicles powered by internal combustion engines have a housing with a connection opening for the fluid connection of an exhaust system, a loudspeaker frame supported by the housing, a membrane supported by the loudspeaker basket, a permanent magnet supported by the speaker basket, and a voice coil carried by a voice coil bobbin. The voice coil is arranged in a magnetic field generated by the permanent magnet and connected to the membrane. The membrane is arranged between the connection opening of the housing and the permanent magnet. The membrane is funnel-shaped and in particular non-developable funnel-shaped (NAWI membrane) or spherical cap, wherein the tip or top surface of the funnel-shaped membrane or the geometric center of the spherical cap membrane facing away from the permanent magnet. The base of the funnel-shaped or kugelkalottenförmigen membrane is thus facing the permanent magnet. Thus, a distance of the tip or top surface of the funnel-shaped membrane or the geometric center of the spherical cap membrane from the permanent magnet is further spaced than the respective base surface of the membrane. Non-developable funnel-shaped or spherical cap-shaped membranes are particularly stiff and thus allow a full-surface and uniform movement of the membrane. Alternatively, however, a cone-shaped membrane is possible.

Due to this configuration and arrangement of the membrane, a particularly large amount of space is provided for accommodating the permanent magnet, the voice coil, the voice coil support and possibly a stop damper, which are arranged wholly or partially inside the volume spanned by the diaphragm and the loudspeaker basket. According to one embodiment, the air volume between the membrane and the connection opening can thereby be reduced by between 4% and 6% of the total housing volume in favor of the volume of air located between membrane and housing on the other side of the membrane compared with a conventional construction of a sound generator for an anti-noise system , At the same volume of air between the membrane and housing on the side of the membrane, which faces away from the connection opening, the overall volume of the speaker compared to a conventional structure can therefore be reduced by between 4% and 6%, in particular, the depth of the speaker can be reduced , Thus, it is possible to reduce the volume of the sound generator with the same sound flow.

According to the invention, a horn provided by the housing at the connection opening is furthermore provided, which can be connected via the connection opening to the intake system or exhaust system of a vehicle operated by internal combustion engine. The loudspeaker basket is supported by the housing via the bell. The tip or top surface of the funnel-shaped membrane or the geometric center of the spherical cap-shaped membrane is arranged in the horn.

Optionally, the horn then support the loudspeaker basket radially outward.

Further, then the horn optionally has the shape of an oblique circular cone whose tip is capped, wherein the top or top surface of the funnel-shaped membrane or the geometric center of the spherical cap membrane a base of the horn penetrates the circular cone described and opens the circular cone at its capped tip into the connection opening of the housing.

According to one embodiment, the tip or top surface of the funnel-shaped membrane is arranged in or passes through a horn and / or the connection opening of the housing.

According to one embodiment, the connection of the loudspeaker basket with the membrane attached to it on the housing is airtight. According to one embodiment, this connection with the housing takes place indirectly via a bell-mouth attached airtight to the housing. Furthermore, the membrane divides an inner volume of the housing into a part separated from the exhaust system or intake system and a part in fluid communication with the exhaust system or intake system via the connection opening.

Since only the membrane and possibly an edge of the speaker basket are located in the part of the housing, which part is in fluid communication with the exhaust system or intake system via the connection opening, only these elements are the hot and loaded with corrosive chemicals exhaust gas or possibly exposed to moist and / or polluted with polluted air sucked. Thus, in addition to the inner wall of the housing, only these elements must be formed of a material which can withstand the exhaust gas and a possibly resulting condensate or the moisture and pollutants of the intake air. The other elements of the sound generator and in particular the sensitive voice coil, which is exposed due to ohmic losses anyway a certain temperature load, however, are shielded by the membrane and the inner wall of the housing of the exhaust gas or the sucked air. As a result, the risk of a short circuit of Reduced voice coil due to condensate of the exhaust gas or humidity of the intake air.

According to one embodiment, the membrane is airtight. Furthermore, with the exception of the connection opening, the housing is airtight. Thus, the two parts of the inner volume of the housing through the membrane (including an existing bead) and the inner wall of the housing and possibly an edge of the speaker basket are hermetically separated from each other.

The airtightly separated from the connection opening part of the inner volume of the housing thus forms an air cushion acting on the membrane. Thus, the membrane operates on the back side to a closed volume and on the front side via the connection opening on the exhaust system or intake system. This rear closed volume is larger with the same size of the housing compared to conventional sound generators, when the permanent magnet and the voice coil as proposed are arranged inside the volume spanned by the membrane and the loudspeaker frame, so that a ratio of rear volume to front volume increases , As a result, the acoustic performance increases with the same volume of construction as with conventional sound generators, so that, conversely, the same acoustic performance as with conventional sound generators can be achieved with a smaller overall volume.

According to one embodiment, the loudspeaker basket further carries a stop damper made of elastic material, which is arranged between the membrane or a centrally carried by the membrane, the voice coil covering cap and the permanent magnet in particular centrally in the interior of the voice coil bobbin and fixed to the permanent magnet. This damper is dimensioned so that it at deflections of the voice coil and thus the Membrane, which exceed a threshold value, against the membrane and / or centrally disposed in the membrane cap acts. By providing the stop damper hard abutment of the membrane and / or the voice coil and / or the voice coil carrier on the permanent magnet is avoided in excessive deflection, or at least damped stop. This avoids damage to the sound generator in the event of overloading.

According to one embodiment, the stop damper also carries a centering device, which is connected to the voice coil bobbin or in the region of the voice coil bobbin with the membrane. The centering device ensures the return of the membrane to the rest position and the centering of the voice coil relative to the permanent magnet.

According to one embodiment, the loudspeaker basket further carries a centering device, which is connected to the voice coil former or in the region of the voice coil carrier with the membrane, thus ensuring the return of the diaphragm to the rest position and the centering of the voice coil with respect to the permanent magnet.

It is emphasized that the provision of a centering device can be dispensed with if a largely smooth guidance of the voice coil in the permanent magnet takes place.

According to one embodiment, the permanent magnet is arranged between the loudspeaker frame and the membrane.

Thus, in this sound generator, the permanent magnet and the voice coil are arranged inside a volume spanned by the diaphragm and the loudspeaker frame. As a result, the depth of the speaker is reduced. This allows the construction volume of the sound generator at the same To reduce sound flow.

According to one embodiment, the membrane is connected to the loudspeaker frame via an airtight bead. This makes it possible to adjust the vibration behavior of the membrane by appropriate choice of material and dimensioning of the bead. Further, bead and membrane are made according to an embodiment of different materials.

According to one embodiment, the loudspeaker basket is made of metal or plastic.

According to one embodiment, the housing of the sound generator is formed of metal or plastic.

According to one embodiment, the housing of the sound generator is formed from two cup-shaped shells, which are soldered, welded, crimped, riveted, glued or screwed together airtight.

According to one embodiment, the membrane is made of metal and in particular of aluminum or titanium or of plastic and in particular of aromatic polyamides.

According to one embodiment, the permanent magnet has rare earths and in particular neodymium and is in particular formed from a neodymium-iron-boron alloy.

Embodiments of an anti-noise system for exhaust systems and / or intake systems of an internal combustion engine-operated vehicle have an anti-noise control and at least one sound generator as described above. In this case, the voice coil of the at least one sound generator is electrically connected to the anti-ballast control. The antisound controller is designed to generate a control signal and to the voice coil of the to spend at least one sound generator. The control signal is suitable for extinguishing sound inside the exhaust system or intake system at least partially and preferably completely in magnitude and phase when the voice coil is operated with this control signal.

Embodiments of a motor vehicle include an internal combustion engine with an engine controller, an intake system and an exhaust system in fluid communication with the internal combustion engine, and the antisound system described above. In this case, the at least one sound generator of the anti-ballast system is in fluid communication with the intake system and / or exhaust system. Further, the antisound control of the antisound system is connected to the engine control of the internal combustion engine of the vehicle.

It should also be understood that the terms used in this specification and the claims for listing features include "comprise," "comprise," "include," "contain," and "with," as well as their grammatical modifications, generally as a non-exhaustive list of features , such as Process steps, facilities, areas, sizes and the like, and in no way preclude the presence of other or additional features or groupings of other or additional features.

Figur 1

schematisch eine perspektivische Ansicht eines Antischall-Systems nach dem Stand der Technik zeigt;

Figur 2

schematisch einen Querschnitt durch einen Schallerzeuger eines Antischall-Systems nach dem Stand der Technik zeigt;

Figur 3

schematisch einen Querschnitt durch einen Schallerzeuger eines Antischall-Systems gemäß einer ersten Ausführungsform der Erfindung zeigt;

Figur 4

schematisch einen Querschnitt durch einen Schallerzeugers eines Antischall-Systems gemäß einer zweiten Ausführungsform der Erfindung zeigt;

Figur 5

schematisch ein Blockdiagramm einer Antischall-Steuerung eines Antischall-Systems gemäß einer Ausführungsform der Erfindung zeigt; und

Figur 6

schematisch ein Kraftfahrzeug zeigt, in welches das erfindungsgemäße Antischall-System integriert ist.

Further features of the invention will become apparent from the following description of exemplary embodiments in conjunction with the claims and the figures. In the figures, the same or similar elements are denoted by the same or similar reference numerals. It should be noted that the invention is not limited to the embodiments of the described embodiments, but by the scope of the accompanying Claims is determined. In particular, the individual features in embodiments according to the invention can be realized in a different number and combination than in the examples given below. In the following explanation of some embodiments of the invention reference is made to the accompanying figures, of which

FIG. 1

schematically shows a perspective view of a prior art antisound system;

FIG. 2

schematically shows a cross section through a sound generator of a prior art antisound system;

FIG. 3

schematically shows a cross section through a sound generator of an anti-sound system according to a first embodiment of the invention;

FIG. 4

schematically shows a cross section through a sound generator of an anti-sound system according to a second embodiment of the invention;

FIG. 5

schematically shows a block diagram of an antisound controller of an antisound system according to an embodiment of the invention; and

FIG. 6

schematically shows a motor vehicle, in which the anti-sound system according to the invention is integrated.

In FIG. 3 schematically is a sectional view through the sound generator 103 according to a first embodiment of the invention shown.

The sound generator 103 has a housing 131, which in its interior receives a modified voice coil speaker 102. The loudspeaker 102 comprises a permanent magnet 121 made of neodymium-iron-boron alloy and a cone-shaped membrane 122 made of plastic, which are jointly carried by a loudspeaker basket 123 made of sheet steel. In this case, the conical membrane 122 is connected at its base radially outward via an elastic bead 127 made of plastic with the loudspeaker frame 123. The top surface of the cone-shaped membrane 122 is closed at the center by a cap 124. In the region of the cover cap 124, a voice coil bobbin 125, which carries a voice coil 126, is attached to the diaphragm 122. The voice coil 126 is disposed in a DC magnetic field generated by the permanent magnet 121. For this purpose, the permanent magnet has a corresponding recess. By applying an alternating current to the voice coil 126, a force is exerted on the diaphragm 122 via the voice coil 126 due to the Lorentz force, causing it to vibrate.

In this case, the permanent magnet 121 and the voice coil bobbin 125 are arranged with the voice coil 126 within the spanned by the loudspeaker frame 123 and the membrane 122 volume, so that the permanent magnet 121 is partially disposed within the cone 122 defined by the cone ', whereby a compact volume of the Speaker 102 is reached. Accordingly, the sound generator 103 can be made compact. The top surface of the cone-shaped membrane 122 with the cap 124 is thus facing away from the loudspeaker basket 123 and also the permanent magnet 121, the base surface of the cone-shaped membrane 122 faces the loudspeaker basket 123 and also the permanent magnet 121.

Next is between the diaphragm 122 and the permanent magnet 121 a stop damper 128 disposed of foam rubber, which is attached to the permanent magnet 121 and in the rest position of the diaphragm 122 is spaced from the cap 124. With excessive deflection of the diaphragm 122, the cap 124 comes into abutment against the stop damper 128, so that a vibration of the diaphragm 122 is damped.

The loudspeaker basket 123 is radially outwardly connected to an inner wall of the housing 131 of the sound generator 103, and is airtight connected to a horn 142, in which the tip of the membrane 122 projects. The bell mouth 142 is connectable via a connection opening 132 of the sound generator 103 and a connecting pipe 141 with the intake system and / or exhaust system of a vehicle operated by internal combustion engine. Since the connection of the cap 124 to the membrane 122 and the connection of the membrane 122 on the bead 127 on the speaker basket 123 airtight, the speaker 102 so together with the horn 142 divides the internal volume of the sound generator 103 into two hermetically separate parts.

Thus, the diaphragm 122 of the speaker 102 is disposed in the installed state of the speaker 102 between the connection opening 132 of the sound generator 103 and the permanent magnet 121, and the permanent magnet 121 between the diaphragm 122 and the loudspeaker frame 123 is arranged.

Thus, the voice coil bobbin 125 with the voice coil 126 and the permanent magnet 121 are hermetically separated from the corrosive exhaust gas by the diaphragm 122.

In FIG. 4 schematically is a sectional view through the sound generator 103 according to a second embodiment of the invention shown. Since this second embodiment of the above in connection with FIG. 3 is very similar to the embodiment described below, only on Differences received and otherwise referred to the above statements.

The second embodiment differs from the first embodiment described above in that the stopper damper 128 further carries a centering device 129 in the form of radially oriented plastic rods, which is connected to the voice coil bobbin 125. Another centering device 143 in the form of a spider is spanned between the loudspeaker frame 123 and the voice coil bobbin 125. The centering devices 129, 143 ensure the return of the diaphragm 122 to the rest position and the centering of the voice coil 126 relative to the permanent magnet 121. It is emphasized that one or both centering devices 129, 143 can be dispensed with.

In FIG. 5 There is shown schematically an antisound system 7 which uses the sound generator 103 described above.

A first sound generator 103 is connected in the region of an orifice 5 via a Y-piece 1 and a connecting pipe 141 to an exhaust system 4 of a vehicle. About the mouth 5 guided exhaust gas is discharged to the outside in the exhaust system 4.

At the Y-piece 1, a first error microphone 9 is provided in the form of a pressure sensor. The error microphone 9 measures pressure fluctuations and thus sound inside the Y-piece 1 in a section downstream of a region in which the fluid connection between the exhaust system 9 and the sound generator 103 takes place. It is emphasized, however, that the error microphone 9 is only optional.

A second sound generator 103 'with a second Speaker 102 'is connected to an intake system 10 of the vehicle. Upstream of a region in which the fluid connection between the intake system 10 and the sound generator 103 'takes place, a second error microphone 9' is arranged in the intake system 10. Again, it is emphasized that the error microphone 9 'is only optional.

The flow direction of the guided in the intake system 10 and the air guided in the exhaust system 4 exhaust gas is shown by arrows.

The loudspeakers 102, 102 'of the sound generators 103, 103' and the error microphones 9, 9 'are electrically connected to an anti-noise controller 8. Further, the anti-noise controller 8 is connected via a CAN bus to a motor controller 61 of an internal combustion engine 6. It is emphasized that the present invention is not limited to a CAN bus.

The exhaust system 4 may further comprise at least one arranged between the engine 6 and the Y-piece 1 catalyst (not shown) for cleaning the emitted from the engine 6 and guided in the exhaust system 4 exhaust gas.

• Anhand von durch die Fehlermikrofone 9, 9' gemessenem Schall und/oder von über den CAN-Bus empfangenen Betriebsparametern des Verbrennungsmotors 6 berechnet die Antischall-Steuerung 8 unter Verwendung eines Filtered-x Least mean squares (FxLMS) Algorithmus zwei digitale Steuersignale, welche jeweils eine weitgehende Auslöschung des im Inneren der Ansauganlage 10 bzw. der Abgasanlage 4 geführten Schalls durch Beaufschlagung mit Anti-Schall erlauben, und gibt diese an den jeweiligen Lautsprecher 102 bzw. 102' des Schallerzeugers 103 bzw. 103' aus.

The general operation of the foregoing antisound system 7 is as follows:

• On the basis of sound measured by the error microphones 9, 9 'and / or operating parameters of the internal combustion engine 6 received via the CAN bus, the anti-noise controller 8 calculates two digital control signals, each using a Filtered-x Least Mean Square (FxLMS) algorithm allow extensive extinction of the guided inside the intake system 10 and the exhaust system 4 sound by applying anti-sound, and gives them to the respective Loudspeaker 102 or 102 'of the sound generator 103 or 103' off.

In the FIG. 6 schematically a motor vehicle with an internal combustion engine 6, an exhaust system 4 and the above-described anti-noise system 7 is shown. The sound generators and the speakers of the anti-noise system are in FIG. 6 not shown separately.

Although a cone-shaped diaphragm has been used for the speaker as above, the present invention is not limited thereto. For example, alternatively, a NAWI membrane can be used. In this case, a NAWI membrane is understood to mean a membrane whose shape can not be developed into a flat surface.

In the figures, only those elements, components and functions are shown in the interest of clarity, which are conducive to an understanding of the present invention. However, embodiments of the invention are not limited to the illustrated elements, components, and functions, but include other elements, components, and functions as required for their use or functionality.

Claims (12)

1. A sound generator (103) for an anti-noise system for influencing sound waves propagating in exhaust systems or intake systems of vehicles driven by an internal combustion engine, comprising:

   a loudspeaker basket (123);

   a membrane (122) supported by the loudspeaker basket (123);

   a permanent magnet (121) supported by the loudspeaker basket (123); and

   a voice coil (126) supported by a voice coil carrier (125), the voice coil (126) being disposed in a constant magnetic field generated by the permanent magnet (121) and connected to the membrane (122);

   wherein the membrane (122) is funnel-like or dome-like, with the top or top face of the funnel-like membrane (122) or the geometric centre of the dome-like membrane (122) facing away from the permanent magnet (121);

   characterized by

   an enclosure (131) having a port opening (132) for a fluid communication with an exhaust system or intake system, wherein the enclosure (131) supports the loudspeaker basket (123) and wherein the membrane (122) is located between the port opening (132) of the enclosure (131) and the permanent magnet (121); and

   a bell mouth (142) mounted to the enclosure (131) at the position of the port opening (132), wherein the bell mouth (142) can be connected via the port opening (132) to the exhaust system or intake system;

   wherein the loudspeaker basket (123) is supported by the enclosure (131) via the bell mouth (142); and wherein the top or top face of the funnel-like membrane (122) or the geometric centre of the dome-like membrane (122) is located within the bell mouth (142).
2. The sound generator (103) of claim 1, wherein the bell mouth (142) supports the loudspeaker basket (123) at its radially outer side.
3. The sound generator (103) of claim 1 or 2, wherein the bell mouth has the shape of an oblique circular cone, the top of which is removed;
   wherein the top or top face of the funnel-like membrane (122) or the geometric centre of the dome-like membrane (122) penetrates the base of the circular cone defined by the bell mouth (142); and
   wherein the removed top of the circular cone merges into the port opening (132) of the enclosure (131).
4. The sound generator (103) according to one of claims 1 to 3,
   wherein the connection between the loudspeaker basket (123) having the membrane (122) fixed thereon and the enclosure (131) is implemented in an air-tight manner; and
   wherein the membrane (122) divides an internal volume of the enclosure (131) into a portion separated from the exhaust system or intake system, respectively, and a portion being in fluid communication with the exhaust system or intake system through the port opening (132).
5. The sound generator (103) according to claim 4,
   wherein the membrane (122) is air-tight; and
   wherein the enclosure (131) is, with the exception of the port opening (132), air-tight;
   so that both portions of the internal volume of the enclosure (131) are separated from each other in an air-tight manner.
6. The sound generator (103) according to one of claims 1 to 5,
   wherein the loudspeaker basket (123) further supports a stop damper (128) made of an elastic material, being disposed inside the voice coil carrier (125) between the membrane (122) and the permanent magnet (121) or between a cover cap (124) covering the voice coil (126) and the permanent magnet (121), and being connected to the permanent magnet (121).
7. The sound generator (103) according to claim 6,
   wherein the stop damper (128) further supports a centering device (129) being connected to the voice coil carrier (125) or to the membrane (122) in the region of the voice coil carrier (125).
8. The sound generator (103) according to one of claims 1 to 7, wherein the loudspeaker basket (123) further supports a centering device (143) connected to the voice coil carrier (125) or to the membrane (122) in the region of the voice coil carrier (125).
9. The sound generator (103) according to one of the claims 1 to 8, wherein the permanent magnet (121) is disposed between the loudspeaker basket (123) and the membrane (122).
10. The sound generator (103) according to one of the claims 1 to 9, wherein the membrane (122) is connected to the loudspeaker basket (123) by an air-tight surround (127).
11. An anti-noise system (7) for an intake system (10) and/or an exhaust-gas system (4) of a vehicle driven by an internal combustion engine, comprising:

    an anti-noise controller (8); and

    at least one sound generator (103) according to one of the claims 1 to 10, with the at least one voice coil (126) of the at least one sound generator (103) being connected to the anti-noise controller (8);

    wherein the anti-noise controller (8) is configured for generating at least one control signal and outputting the least on control signal to the at least one voice coil (126), with the control signal being adapted to cancel noise inside the intake system and/or the exhaust system (4) at least partially, and in particular completely, when the at least one voice coil (126) is operated with the control signal.
12. A motor vehicle, comprising:

    an internal combustion engine (6) with an engine control unit (61);

    an intake system (10) and an exhaust system (4), both being in fluid communication with the internal combustion engine (6); and

    an anti-noise system (7) according to claim 11,

    wherein the at least one sound generator (103) of the anti-noise system (7) is in fluid communication with the intake system (10) and/or the exhaust system (4); and

    wherein the anti-noise controller (8) of the anti-noise system (7) is connected to the engine control unit (61) of the internal combustion engine (6) of the vehicle.

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