EP3020038B1 - Sonic transducer assembly - Google Patents

Description

State of the art

The invention relates to a sound transducer arrangement with a housing in which a plurality of transducer elements are arranged. The invention also relates to a vehicle equipped with such a transducer assembly.

Ultrasonic transducers are used in vehicles within the framework of driver assistance systems in order to monitor the environment of the vehicle during parking, for example. For example, 4 to 6 ultrasonic transducers are integrated in the rear and / or front bumper of the vehicle. In order to improve the spatial resolution of such systems, ultrasound transducer arrays with a plurality of individual transducers are used in addition to individually implemented ultrasonic transducers.

Such ultrasonic transducers are exposed to high levels of environmental impact, such as rockfall, temperature changes or weather conditions, which compromise functionality and, at worst, can lead to irreparable damage. Therefore, the transducer elements of the ultrasonic transducers are usually arranged with a separate seal in a housing. In order not to influence the vibration characteristics, decoupling elements are additionally provided. In addition to the functional aspects, the seal should not adversely affect the optical properties of the surface of such ultrasonic transducers. For ultrasonic transducers with a single transducer element different solutions for sealing are known.

Out WO 2008 025 608 A2 a housing for receiving a diaphragm pot is known, which provides a filling material for a vibration-damped and tight positive connection of the diaphragm pot and the decoupling component with the housing. In this case, the decoupling component fills the gap between an edge of an opening of the housing and the diaphragm cup sealingly.

DE 10 2009 022 187 A1 describes an ultrasonic transducer in a closed housing with a piezoceramic for generating ultrasonic vibrations in a diaphragm pot. The entire housing is filled with the membrane pot with a granulate and sealed with a lid.

The DE 101 25 272 A1 describes an ultrasonic sensor with a diaphragm, which is arranged in a housing. Between diaphragm and housing, a sealing decoupling ring is still provided.

The WO 2011/051040 A1 describes an ultrasonic transducer in which a gap between the transducer housing and the transducer element is filled with a silicone elastomer. The plastic is in this case introduced into the intermediate space such that a web forms, which terminates flush with the sound-sensitive side of the transducer element.

The document US 2008/0238259 A1 describes an ultrasonic array in which the gap between successive transducer elements is filled with one.

In ultrasonic transducer arrays, which represent a composite of individual transducers, there are further difficulties in sealing, since not all individual transducers are enclosed by a housing or other components. Furthermore, sealing concepts for ultrasonic arrays should fulfill the above-mentioned functional and optical requirements. Therefore, there is a continuing interest in providing sealing concepts for single transducer and ultrasonic transducer arrays that have high density while meeting functional and optical requirements.

Due to the high dispersion of parameters in mass production, conventional ultrasonic sensors often exhibit high amplitude scattering as well as high scattering in the resonance frequency. In order to compensate for these effects, such ultrasonic sensors can be selectively damped in terms of vibration mechanics. This attenuation has an effect on the Nahmessfähigkeit the operating in the transmit-receive mode ultrasonic sensors, since the minimum measuring distance of an ultrasonic sensor is known to be directly related to the decay of an excited diaphragm of the sensor, which in turn is determined by the mechanical damping. In Conventional systems, the vibration damping mechanical, for example, with a foamed 2-component elastomer (eg Fermasil, Fa. Sonderhoff) performed, which is introduced into the interior of the diaphragm pot. This process is usually insufficiently controllable, since the attenuation achieved is determined mainly by the formation of micro-mechanical air bubbles during curing (foaming) of the 2-component elastomer. Furthermore, the known ultrasound sensors manufactured in this way have insufficient long-term stability. Under temperature load (Operation in the vehicle) irreversible amplitude changes are observed, which significantly reduces the measurement range.

Disclosure of the invention Advantages of the invention

The invention is disclosed in claim 1. Further embodiments are disclosed in the dependent claims.

According to the invention, a sound transducer arrangement is proposed with a housing in which a plurality of transducer elements are arranged, wherein a gap between the housing and the transducer element or in the case of several transducer elements, a gap between successive transducer elements is filled with a plastic having a modulus of elasticity <10 N / mm ² ,

By using a plastic with a low modulus of elasticity <10 N / mm ² , a sealing of the transducer assembly is made possible, which acts on the one hand sealing and on the other hand, the vibration characteristics of the system minimally affected. Thus, the coupling between the individual elements, so the transducer elements and the housing, low. In addition, such a plastic leads to a low attenuation. This results in low sensitivity changes, which directly affect the achievable range. The sound transducer arrangement according to the invention thus enables a robust and stable sealing of the sound transducer arrangement without additional decoupling elements. Furthermore, such a transducer assembly is simple and inexpensive to manufacture. This results in further advantages, such as mass production suitability and high process reliability. The robust, stable damping of the entire transducer assembly can be adjusted specifically via the elastic modulus of the elastomer between the individual transducer elements. This can be done alone or in combination with further damping measures. As a result, it is possible to dispense with additional damping via a foamed elastomer material.

A sound transducer assembly in the present context refers to an arrangement that receives and / or transmits sound waves. For this purpose, the sound transducer arrangement comprises at least two transducer elements which can be designed, for example, as flexural vibrators or thickness oscillators. The transducer element is preferably suitable for receiving and / or transmitting ultrasonic waves having a frequency in the range from 16 kHz to 1 MHz, particularly preferably in the range 30-150 kHz, approximately 50 kHz.

If the sound transducer arrangement comprises several transducer elements, this is also referred to as a sound transducer array. Several transducer elements are arranged in a housing, wherein the sound-sensitive side of the transducer elements is aligned with the environment and thus forms the sound-sensitive side of the transducer array. Furthermore, the individual transducer elements can be configured as bending vibrators or as thickness vibrators. Also, bending vibrators and thickness vibrators can be combined in a transducer array.

Flexural vibrators comprise, for example, a diaphragm to which a piezo element adjoins in order to convert vibrations of the diaphragm into mechanical signals of the piezoelectric element, such as a voltage, and vice versa electrical signals, such as a voltage, via mechanical deformation of the piezoelectric element in vibrations of the membrane. In addition or as an alternative to the membrane, the bending oscillator may comprise a bending transducer element. In this case, the bending transducer element can be U-shaped with a sound-effective side and on both sides adjoining fastening sides. On one of the sides of the bending transducer element, preferably on the inner, not the sound field side facing, the piezoelectric element may further be arranged to convert vibrations of the diaphragm and / or the bending transducer element via mechanical deformation of the piezoelectric element into electrical signals, such as a voltage, and vice versa , Thick vibrators include, for example, a front body and a rear body, between which a piezoelectric element is arranged to transmit vibrations via the front body in the form of mechanical deformations on the piezoelectric element and into electrical signals, such as a voltage to convert, and vice versa.

According to the invention, a plurality of transducer elements are arranged in the housing to form a transducer array. In this case, the gap between successive transducer elements and the gap between the housing and the subsequent transducer element is filled with a plastic having a modulus of elasticity <10 N / mm ² . In such an arrangement, the transducer elements are preferably completely enclosed by the plastic in order to decouple the individual components of the transducer array from each other.

According to the invention, the intermediate space is filled with a plastic which has a modulus of elasticity <10 N / mm ² , preferably <5 N / mm ^2, and particularly preferably between 0.25 and 2.5 N / mm ² . By filling the spaces between the housing and individual transducer elements with such a plastic, webs between the individual components, so the housing and / or the transducer elements that do not affect the functionality and at the same time provide the necessary tightness. As the plastic, for example, a polymer such as epoxy resin, polyester or an elastomer such as natural rubber, silicone-based elastomers or silicone rubber and mixtures thereof can be used.

In order to increase the adhesion between the plastic and the sealing surfaces of the transducer elements and / or the housing, the surface of the housing and / or the surface of the transducer element may be at least partially surface-treated, in particular roughened or activated. Preferably, at least the sealing surfaces of the housing and / or the transducer element are roughened. This can be done for example by plasma treatment, pickling or sandblasting.

In a further embodiment, the plastic is introduced in the intermediate space in such a way that a web forms which terminates flush with the sound-sensitive side of the transducer element. As a result, the surface ripple is reduced to improve the optical properties of the transducer assembly.

In a further embodiment, the plastic is introduced in the intermediate space in such a way that a web is formed which forms a projection on the sound-sensitive side of the transducer element. Thus, the web covers with the projection part of the sound-sensitive surface of the transducer element. In order to avoid functional impairments, the projection of the web preferably occupies an area not more than 1/6, particularly preferably not more than 1/10 of the sound-sensitive surface of the transducer element.

Furthermore, the web may be larger in the longitudinal direction than the thickness of a component of the transducer element in order to facilitate the adjustment of the transducer element. For example, the length of the web in a bending oscillator be greater than the thickness of the membrane, so that the adjoining the diaphragm piezoelectric element is easily adjustable.

According to the invention, the housing and the web between the housing and the subsequent transducer element are designed in one piece. As an example not part of the present invention, the Housing form a separate part, wherein the gap between the housing and subsequent transducer element is filled with the plastic. So the plastic can be injected or poured into the gap. In this example, an elastomer is particularly suitable as a plastic. According to the invention, the housing and the web for sealing from a plastic, in particular an epoxy resin, are integrally formed.

Here, the web and the housing can be formed by injection molding. This design makes it possible to manufacture the housing and the webs in one step. In addition, the number of sealing surfaces in this embodiment is reduced.

In a further embodiment, a film is arranged on the sound-sensitive side of the sound transducer arrangement. In this case, the film can cover the sound-sensitive side of the sound transducer arrangement in whole or in part. The film may have a thickness of 10 to 500 .mu.m, preferably from 20 to 250 .mu.m and particularly preferably from 25 to 150 .mu.m. Preferably, the film is impermeable to moisture, such as water, and thus also acts sealingly. These are, for example, films made of metal or plastic, such as polyethylene imine (PEI), polyetheretherketone (PEEK) or polyimide (PI). A composite with several film layers is conceivable. The film improves both the sealing effect and the chemical resistance to aggressive media such as oils, fuels, acids, alkalis, brake fluid, salt water, cola or cold cleaners. Also, the application of paint is simplified because the optical properties of the paint are not degraded by differences in material in the ground.

The film can also be glued to the sound-sensitive side of the transducer assembly, welded or sealed. Preferably, the film is adhered to compensate for surface ripples of the sound-sensitive side with the aid of the adhesive and at the same time produce a tight connection. As an adhesive is particularly suitable an epoxy resin. The adhesive may for example be sprayed on, laminated or applied by screen printing. In addition, the adhesive may also contain fillers of a defined size to set a desired adhesive thickness and damping. Particularly preferred is the use of a film on which the adhesive has been applied in advance.

The robust, stable damping of the transducer assembly can be targeted on the thickness of the film and / or the thickness of the adhesive, the modulus of elasticity of the selected adhesive, as well the elastic modulus of the elastomer can be adjusted between the transducer elements. This can be done alone or in combination. This eliminates additional damping via a foamed elastomeric material (such as Fermasil), associated with the disadvantages described.

In a further embodiment, the web can have a curvature on the sound-sensitive side of the sound transducer arrangement. Such a design is particularly advantageous if no film is applied to the sound-sensitive side of the transducer assembly. Because of the deliberately emphasized curvature, the visible surface flow is interrupted and the surface waviness does not appear visible.

In a preferred embodiment of the invention, the transducer elements have piezoelectric elements, wherein the piezoelectric elements are electrically contacted by means of a flexible, electrically conductive foil, a so-called flex foil. Particularly preferably, below the means of the flexible, electrically conductive foil contacted piezoelectric elements, in particular a foamed, elastomeric mat is inserted. Alternatively, a damping material with or without gas inclusions is introduced below the piezoelectric elements contacted by means of the flexible, electrically conductive film.

According to the invention, a vehicle is also proposed which is equipped with the above-described sound transducer arrangement.

1. a) Bereitstellen von Komponenten für ein oder mehrere Wandlerelement(e);
2. b) Anordnen mindestens einer Komponente des Wandlerelements; und
3. c) Ausbilden der Schallwandleranordnung, wobei Zwischenräume zwischen Komponenten oder zwischen einer Komponente und einem Gehäuse mit einem Kunststoff gefüllt werden, der einen Elastizitätsmodul < 10 N/mm² aufweist.

Furthermore, not according to the invention, a method for producing the sound transducer arrangement is proposed, which comprises the following steps:

1. a) providing components for one or more transducer element (s);
2. b) arranging at least one component of the transducer element; and
3. c) forming the sound transducer assembly, wherein gaps between components or between a component and a housing are filled with a plastic having a modulus of elasticity <10 N / mm ² .

The method preferably serves for producing the above-described sound transducer arrangement. Accordingly, features which are described in connection with the sound transducer arrangement, also apply to the method and vice versa.

A component refers to components that serve to form the transducer element. Components of a bending transducer are, for example, the membrane, the piezoelectric element or the bending transducer element. Components of a thickness vibrator are, for example, the front body, the rear body or the piezoelectric element.

Thus, individual components, such as the membrane of a bending oscillator or the front body of a thickness vibrator, can be arranged in an array, and then filled the interstices. In this case, the transducer element is completed after filling the gaps. Alternatively, finished transducer elements can be arranged in an array and then the gaps are filled. The arrangement of the components or the transducer elements can be done on a reference plate on which the gaps are filled and thus the sound transducer assembly is formed.

According to an example not part of the invention, components for a plurality of transducer elements and a prefabricated housing are arranged. Subsequently, the interspaces between the arranged components and between the housing and the subsequent components are filled with a plastic having a modulus of elasticity <10 N / mm ² , preferably <5 N / mm ² and particularly preferably 2 N / mm ² . In another example, not part of the invention components are arranged for a plurality of transducer elements and then formed in one step, the housing and the spaces between the components filled. For this purpose, a plastic with a modulus of elasticity <10 N / mm ² , preferably <5 N / mm ² , for example epoxy resin or silicone rubber is used

According to an example not part of the invention, the filling of the interstices takes place by spraying, transfer molding or casting of the plastic. By filling the gaps, webs are formed which terminate flush with the component on the sound-sensitive side or which form a projection which at least partially covers the component on the sound-sensitive side. In the longitudinal direction, the webs may be formed such that their length is greater than the thickness of the components, such as the membrane. In a further embodiment, a film is applied, preferably glued, to the sound-sensitive side of the sound transducer arrangement. For forming the sound transducer arrangement, for example, a thermo-compression method for Use, wherein the webs and the adhesive for the film with the remaining composite are cured under pressure and temperature.

Brief description of the drawings

Figur 1

ein Beispiel nicht Teil der Erfindung eines Schallwandlerarrays mit mehreren Biegeschwingern als Wandlerelemente, das gegenüber Umwelteinflüssen abgedichtet ist,

Figur 2

eine Ausführungsform eines Schallwandlerarrays mit mehreren Biegeschwingern als Wandlerelemente, das gegenüber Umwelteinflüssen abgedichtet ist.

Further aspects and advantages of the invention will now be described in more detail with reference to the accompanying figures. Hereby show:

FIG. 1

an example not part of the invention of a transducer array with multiple bending vibrators as transducer elements, which is sealed against environmental influences,

FIG. 2

an embodiment of a transducer array with multiple bending vibrators as transducer elements, which is sealed against environmental influences.

Embodiments of the invention

FIG. 1 shows an example of an example not part of the invention of a transducer array 10 with multiple bending vibrators 12 as transducer elements, wherein the transducer array 10 is sealed against environmental influences.

The transducer array 10 includes, for example, three bending vibrators 12 which are arranged in a housing 14. The housing 14 may be, for example, a plastic housing. In particular, the housing may be molded on the basis of a polymer, such as polyethylene (PE), polypropylene (PP), polyurethane (PU), polyvinyl chloride (PVC) or polycarbonate (PC) polystyrene (PS) or glass fiber reinforced plastics. The flexural vibrators 12 comprise a bending transducer element 16, which is designed as an example U-shaped. In this case, the bending transducer element 16 has a sound-effective surface 22 and two side walls 24. The bending transducer element 16 may be made of a metal, a plastic or a ceramic, for example. Above the sound-sensitive surface 22 of the bending transducer element 16, a piezoelectric element 18 is arranged. The piezoelectric element 18 may be glued or welded. Above the piezoelectric element 18, a membrane 20 is further arranged.

FIG. 1 shows a section of a transducer array 10, in which the bending vibrators 12 are arranged in a row next to each other, that the sound-sensitive surfaces of the bending vibrator 12 are outwardly, ie, aligned to the environment 26, out. These surfaces form the sound-sensitive surface 32 of the transducer array 10. When using the transducer array 10 in the vehicle, the sound-sensitive surface 32 is the visible surface. For clarification of the arrangement, the detail 28 shows a top view of the transducer array 10 with the bending vibrators 12 exemplified.

Between the bending vibrators 12 and between the bending vibrators 12 and the housing 14, a gap 6 is arranged in each case. These interspaces 6 are filled with an elastomer such as a thermosetting elastomer such as polyurthane elastomer, natural rubber, silicone-based elastomers or silicone rubber, or mixtures thereof. Thus, elastomeric webs 17, which seal off the transducer array 10, are formed between the bending vibrators 12 and between the housing 14 and the subsequent bending vibrator 12. For a stable and robust seal is realized, which protects the transducer array 10 in particular from environmental influences, such as the ingress of liquid and damage by rockfall, shaking loads or temperature changes. In addition, the functionality and in particular the vibration properties of the transducer array 10 are minimally influenced by this type of sealing.

The elastomeric webs 17 are, in the in FIG. 1 shown, longer than the thickness of the membrane 20. This results below the membrane 20 or on the side of the membrane 20, which points away from the sound-sensitive side 32 of the transducer array 10, a space in each of which the piezo elements 18 for the individual Bending vibrator 12 can be introduced. This facilitates the subsequent introduction of the piezoelectric elements 18, their longitudinal adjustment, since tilting or offset relative to the membrane 20 can be avoided.

The elastomer is preferably chosen so that the modulus of elasticity is <10 N / mm ² , preferably <5 N / mm ² and particularly preferably <2.5 N / mm ² . As a result, the coupling between the bending vibrators 12 and the vibration damping of the transducer array 10 is minimized. In particular, the low attenuation has a direct effect on the achievable range of the transducer array 10 and leads to an increase in the range. In addition, by the elastomer with low Elastic modulus ensures the adhesion to the bending vibrator 12 and the housing 14, even under thermal shock conditions. This ensures that the stresses on the sealing surfaces 30 are below the adhesion values of the elastomer and that tearing off of the sealing surfaces 30 can be avoided.

The interstices 6 can be filled with the elastomer in different ways. For example, injection molding (injection molding) methods or casting methods in which an elastomer-based casting resin is poured into the interspaces 6 are suitable. As the elastomer, a natural rubber, a polyurethane elastomer, a silicone-based elastomer such as silicone rubber or a mixture thereof can be used. In addition to the elastomers mentioned, it is also possible to use other elastomers known to the person skilled in the art which have a modulus of elasticity of <10 N / mm ² .

To further increase the adhesive strength, the flexural transducer elements 16 and the housing 14 may continue to be surface treated. For example, the surfaces may be roughened or activated by a plasma treatment or pickling to allow better adhesion of the components to be joined.

On the sound-sensitive side 32 of the transducer array 10 - ie the side of the transducer array 10, which is aligned to the environment 26 - a film 34 is further arranged. The film 34 is adhered with an adhesive 36, such as an epoxy resin. Furthermore, the film 34 may have a thickness of 10 to 500 μm, and preferably of 20 to 250 μm. Preferably, the film 34 is also tight against moisture, such as water. For example, films of polyethyleneimine (PEI), polyetheretherketone (PEEK) or polyimide are suitable for this purpose. Polyimide films are available, for example, under the name Kapton®. By choosing the thickness of the film 34, the mechanical damping of the transducer array 10 can advantageously be adjusted. Also, the thickness and Young's modulus of the adhesive 36, as well as the modulus of elasticity of the elastomer in the interstices 6, may alternatively or additionally be varied to achieve a desired damping.

The electrical contacting of the piezoelectric elements 18 can be done for example by means of a flexible, electrically conductive film (not shown for reasons of clarity). To set the mechanical damping of the transducer array 10 may alternatively or in addition to the measures already described, a thin Elastomer mat below the contacted by means of the flexible, electrically conductive film piezo elements 18 are inserted. Such an elastomer mat can also be foamed and formed from a material such as Armaflex. The mat can be coated with a self-adhesive and thus fully automatically pressed in the manufacture of the transducer array 10 on the flexible, electrically conductive film. As an alternative to an elastomer mat, it is possible, as in conventional ultrasonic sensors, to carry out a vibration-mechanical damping, for example by means of a foamed elastomer (eg Fermasil) or other damping materials with or without gas inclusions, which is filled under the piezoelements 18 contacted by means of the flexible, electrically conductive foil.

FIG. 2 shows an example of an embodiment of a transducer array 10 with a plurality of bending vibrator 12 as transducer elements, wherein the transducer array 10 is sealed against environmental influences.

The structure of the transducer array 10 according to FIG. 2 is essentially the same as the FIG. 1 , In contrast to FIG. 1 However, the seal between the individual bending vibrators 12 and between the bending vibrators 12 and the housing 14 by webs 38 is formed with a projection 40. Thus, the webs 38 are not flush with the membrane 20 of the flexural vibrator 12, but at the sealing surfaces 30 between the webs 38 and the membranes 20 each have a projection 40. The projection 40 extends above the membrane 20 over a surface < 1/6, preferably <1/10 of the surface of the membrane 20 can take. In order to reduce the visibility of the surface waviness, the webs 38 on the sound-sensitive side 32, which is visible in the installed state in the vehicle, a curvature 39 on.

Furthermore, in this embodiment, as in FIG FIG. 2 shown, the housing 14 and the webs 38 may be made of the same material. For example, the housing 14 and the web 38 can be formed for subsequent bending vibrator by injection molding. Thus, a sealing surface 30 between the housing 14 and the subsequent bending oscillator 12 can be avoided. As the material for the housing 14 and the webs 38 is for example epoxy resin or elastomers such as natural rubber, polyurethane elastomer, silicone-based elastomer or silicone rubber. Also in this case it is advantageous to choose a material which has a low modulus of elasticity <10 N / mm ² , preferably <5 N / mm ² .

The invention is not limited to the examples described herein or the aspects highlighted therein. Rather, within the range specified by the claims a variety of other variations are conceivable, which are within the scope of expert action. In particular, it is conceivable that in the Figures 1 and 2 to combine shown embodiments. Thus, the sound transducer array 10 according to FIG. 2 are also provided with a film 34 which is mounted on the sound-sensitive side 32 of the transducer array 10, wherein by selecting the thickness of the film 34, the attenuation of the transducer array 10 can be adjusted. Also, the thickness and elastic modulus of the adhesive film adhesive 34 and the modulus of elasticity of the material of the webs 38 may alternatively or additionally be varied to achieve a desired damping.

Furthermore, it is possible to use the concepts shown for sealing and damping in individual transducers. An insert with thickness vibrators instead of bending vibrators 12 as transducer elements is possible.

Claims (13)

1. Sonic transducer assembly (10) having a housing (14) and having a plurality of transducer elements (12) which are arranged in the housing (12),
   wherein an interspace (6) between the housing (14) and the transducer elements (12) and an interspace (6) between successive transducer elements (12) are filled with a plastic which has a modulus of elasticity < 10 N/mm²,
   wherein the plastic in the interspace (6) is introduced in such a way that a web (17, 38) is formed, which ends flush with the sound-sensitive side (32) of the transducer element (12) or which forms a projection (40) on the sound-sensitive side (32) of the transducer element (12),
   wherein the housing (14) and the web (17) between the housing (14) and the following transducer element (12) are configured in one piece, and
   wherein the transducer elements (12) are configured as flexural resonators or as thickness-mode resonators.
2. Sonic transducer assembly according to Claim 1, characterized in that the plastic contains an epoxy resin, an elastomer or a combination thereof.
3. Sonic transducer assembly according to Claim 1 or 2, characterized in that the surface of the housing (14) and/or the surface of the transducer element (12) is at least partly surface treated, in particular roughened.
4. Sonic transducer assembly according to one of Claims 1 to 3, characterized in that the web (17, 38) is larger in the longitudinal direction than the thickness of a component (20) of the transducer element (12).
5. Sonic transducer assembly according to one of Claims 1 to 4, characterized in that a film (34) is arranged on the sound-sensitive side (32) of the sonic transducer assembly (10).
6. Sonic transducer assembly according to Claim 5, characterized in that the film (34) is adhesively bonded, welded, laminated or sealed onto the sound-sensitive side (32) of the sonic transducer assembly (10).
7. Sonic transducer assembly according to Claim 5, characterized in that the film (34) is bonded onto the sound-sensitive side (32) of the sonic transducer assembly (10) by means of an adhesive (36), and the adhesive (36) contains additional fillers of defined size.
8. Sonic transducer assembly according to one of Claims 5 to 7, characterized in that the damping of the sonic transducer is adjusted by the thickness of the film (34) and/or the thickness of the adhesive (36) and/or the modulus of elasticity of the adhesive (36) and/or the modulus of elasticity of the plastic in the interspaces (6).
9. Sonic transducer assembly according to one of Claims 1 to 8, characterized in that the web (17, 38) on the sound-sensitive side (32) of the sonic transducer assembly (10) has a curvature (39).
10. Sonic transducer assembly according to one of Claims 1 to 9, characterized in that the transducer elements (12) have piezoelectric elements (18), wherein electrical contact is made with the piezoelectric elements (18) by means of a flexible, electrically conductive film.
11. Sonic transducer assembly according to Claim 10, characterized in that an in particular foamed elastomer mat is inserted underneath the piezoelectric elements (18) with which contact is made by means of the flexible, electrically conductive film.
12. Sonic transducer assembly according to Claim 10, characterized in that a damping material with or without gas inclusions is introduced underneath the piezoelectric elements (18) with which contact is made by means of the flexible, electrically conductive film.
13. Vehicle equipped with a sonic transducer assembly (10) according to one of Claims 1 to 12.

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