Acoustically effective component for a motor vehicle, and method for manufacturing same

Abstract

The invention relates to an acoustically effective component (1) for a motor vehicle, the component comprising a mass layer (2) and an absorber layer (3) acting as a spring, wherein the absorber layer (3) has a first side (31) and a second side (32) opposite the first side, wherein the first side (31) is connected to the mass layer (2) and the second side (32) is designed for attachment to a vibrating surface, wherein the mass layer (2) is formed from a polyurethane foam. According to the invention, the PUR foam has a mixed-cell or closed-cell structure, and the absorber layer (3) is integrally formed with and made from the same material as the mass layer (2), and comprises a plurality of recesses (4) which extend between the first side (31) and the second side (32) of the absorber layer (3). The invention also relates to a method for manufacturing such an acoustically effective component.

Description

[0001] Acoustically effective component for a motor vehicle and a method for producing the same

[0002] The invention relates to an acoustically effective component for a motor vehicle, comprising a mass layer and an absorber layer acting as a spring, wherein the absorber layer has a first side and a second side opposite thereto, wherein the first side is connected to the mass layer and the second side is designed for connection to a vibrating surface, wherein the absorber layer is designed as a fleece and from a polyurethane.

[0003] Modern motor vehicles feature a multitude of acoustically effective components designed to minimize noise pollution for occupants in the passenger compartment. Examples include the paneling of the body bulkhead, also known as the firewall, or the body floor. Such components can also be used as door insulation or wheel house insulation. Particularly at high speeds, road noise and the air flowing past the vehicle generate considerable noise. Further noise emissions also come from the vehicle's engine.

[0004] In addition to the stringent requirements regarding the noise levels prevailing in vehicles while driving, modern motor vehicles must also be manufactured, operated, and recycled in a resource-efficient manner. Therefore, it is not only important to optimize the manufacturing process accordingly, but it is also crucial that the vehicle can be recycled as completely as possible after its service life has been reached, so that as much material as possible can be reused and returned to the cycle.

[0005] A wide variety of acoustically effective components for motor vehicles are known from the prior art. For example, DE 10 2022 121 174 B3 discloses such a component, which comprises an absorber layer and a mass layer, with the absorber layer being formed as a nonwoven and made of PET. The mass layer is made of a wide variety of different materials. The components previously known from DE 10 2022 121 174 B3 are therefore only recyclable to a very limited extent. Furthermore, such a component has a relatively high mass in order to meet the acoustic requirements.

[0006] Against the background described above, it is an object of the present invention to provide an acoustically effective component for a motor vehicle that can be recycled to a high degree and simultaneously exhibits very good acoustic properties. Furthermore, it is an object of the present invention to provide a method for producing such an acoustically effective component for a motor vehicle.

[0007] The problem is solved by an acoustically effective component having the features of patent claim 1, as well as a method for producing an acoustically effective component having the features of patent claim 21.

[0008] The subclaims each relate to preferred embodiments or further developments of the present invention, the respective features of which can be freely combined with one another within the scope of what is technically reasonable, even across the category boundaries of the various claims.

[0009] An acoustically effective component for a motor vehicle is proposed, comprising a mass layer and an absorber layer acting as a spring, wherein the absorber layer has a first side and a second side opposite thereto, wherein the first side is connected to the mass layer and the second side is designed for connection to a vibrating surface,

[0010] As is known from the prior art, the mass layer is formed from a PUR foam. According to the invention, the PUR foam is mixed-cell or closed-cell, and the absorber layer is formed integrally with the mass layer and from the same material. Furthermore, the absorber layer has a plurality of recesses extending between the first and second sides of the absorber layer.

[0011] By introducing recesses into the absorber layer, the mechanical and thus acoustic properties of the absorber layer can be specifically adjusted. This allows the compressibility of the absorber layer to be significantly reduced compared to that of the mass layer. The average density, or weight per unit area, of the absorber layer is also reduced by introducing recesses compared to the absorber layer. Both of these factors together result in a spring-mass system with the desired acoustic properties. The cells of the mixed-cell or closed-cell PUR foam are at least partially insulated from one another. This at least partially closed cell structure offers the advantage that the mass layer exhibits high dimensional stability and improved acoustic insulation properties.This results in the surprising combination of advantageous acoustic properties and, at the same time, high dimensional stability, provided by the inventive solution. In other words, the reduction in dimensional stability resulting from the recesses is essentially compensated for by the use of a mixed-cell or closed-cell PUR foam.

[0012] The mass layer can alternatively also be called the heavy layer.

[0013] The mechanical and acoustic properties of the absorber layer can be specifically adjusted by selecting, for example, hole geometry, hole dimensions, number of holes, hole arrangement and hole density.

[0014] Thanks to the solution according to the invention, an acoustically effective component can be provided which has very good acoustic properties that correspond to the properties of the components previously known from the prior art.

[0015] Furthermore, it can be manufactured in a single production step. This results in significant cost advantages over prior art components, which often require multiple manufacturing steps due to their multi-component design.

[0016] Furthermore, the acoustically effective component according to the invention is fully or almost fully recyclable, since both the absorber layer and the mass layer are made of polyurethane, also abbreviated to PUR for short. Thus, unlike the prior art, there is no composite material made of a wide variety of materials that are hardly or not at all recyclable because these individual, different materials are almost inseparably bonded to one another. According to the invention, the individual layers are made of a similar material, i.e., PUR. For the purposes of the invention, a polyurethane foam is understood to mean a foam made of polyurethane (PUR for short), and is accordingly referred to as PUR foam for short.

[0017] Both the absorber layer and the mass layer may contain a small proportion of substances other than PUR, but this does not affect the recyclability of the acoustically effective component. Typically, these are substances that are not particularly detrimental from a technical perspective and / or represent minimal impurities in the PUR material of the absorber layer or the PUR material of the mass layer. This proportion of other substances is less than 1.0 percent by weight.

[0018] Weight percent refers to the mass fraction. Weight percent (wt%) can also be referred to as mass percent.

[0019] The second side of the absorber layer is designed to be connected to a vibrating surface. It is therefore the absorber layer that is designed (suitable) to be connected to the vibrating surface. The term "connected" means that the second side of the absorber layer can interact with the vibrating surface. This can be achieved, for example, by touching, so that the vibrations of the vibrating surface can be transferred to the absorber layer.

[0020] Furthermore, it can be achieved, for example, by a material-to-material connection such as gluing and / or by a form-fitting connection such as coupling into an undercut or by attaching using separate clasps or clips.

[0021] The acoustically effective component represents a spring-mass system, in which the absorber layer is the spring and the mass layer forms the mass of the spring-mass system. The absorber layer serves to dampen sound, while the mass layer is intended for sound insulation.

[0022] Sound dampening reduces the volume or intensity of noise, while sound insulation aims to block or minimize the transmission of sound waves from one location to another. The mass layer thus preferably forms an acoustic barrier.

[0023] The sound emanating from the vibrating surface thus first enters the absorber layer and is dampened there. The remaining sound that has penetrated the absorber layer is stopped or almost stopped in its propagation by the mass layer, i.e., dampened.

[0024] According to the invention, the absorber layer and the mass layer are formed in one piece and from the same material, so that the PUR foam in the mass layer and in the absorber layer has substantially the same density.

[0025] However, it is also possible that the local density in the mass layer and the material of the absorber layer differ from each other, which can be due to the manufacturing of the component in a mold and the locally different geometry. However, the density variation can also be negligibly small.

[0026] Motor vehicles, as defined by the inventions, are understood to be land vehicles that are propelled by mechanical power without being tied to railway tracks. These include, in particular, passenger cars, trucks, and buses.

[0027] Preferably, the mass layer itself is dimensionally stable, i.e. it does not deform due to its own mass.

[0028] However, the dimensional stability of the component is further increased by the combination with the structured absorber layer made of the same material, so that at least the component as a whole is dimensionally stable.

[0029] In an advantageous embodiment, the absorber layer has a thickness between 5 and 30 mm. Studies have shown that an absorber layer in such a thickness range offers an optimum balance between acoustic absorption and mass. It has proven particularly advantageous if the thickness of the absorber layer is between 7.5 and 20 mm, and particularly preferably approximately 15 mm.

[0030] In an advantageous embodiment, the mass layer has a thickness between 1 and 20 mm. Studies have shown that a mass layer in such a thickness range offers an optimum balance between its acoustic insulation effect and its mass. It has proven particularly advantageous if the thickness of the mass layer is between 2 and 15 mm, and particularly preferably approximately 5 mm.

[0031] The optimal values ​​for the respective layer thicknesses of the mass and absorber layers also depend on the density of the PUR foam used. However, it has generally proven advantageous if, regardless of the absolute values ​​for the respective layer thicknesses, the thickness of the absorber layer is at least 30% greater than the thickness of the mass layer. It has proven particularly advantageous if the thickness of the absorber layer is at least 50% greater than the thickness of the mass layer. The component according to the invention exhibits particularly advantageous acoustic properties if the thickness of the absorber layer is at least 80% greater than the thickness of the mass layer.

[0032] In a further advantageous development, the absorber layer has a basis weight between 200 g / m 2 and 1,000 g / m 2Thanks to such a weight per unit area, the absorber layer can optimally fulfill its damping function. It has been shown that such an absorber layer, acting as a spring in a spring-mass system, achieves very good sound dampening properties. A weight per unit area of ​​between 400 g / m² has proven particularly advantageous. 2 and 800 kg / m 2 proven.

[0033] In an advantageous embodiment, the mass layer has a basis weight between 1,200 g / m 2 and 2,400 g / m 2 Thanks to such a density, the mass layer exhibits excellent sound barrier properties. It has been shown that such a mass layer, acting as the mass of the spring-mass system, achieves very good sound dampening properties for the component according to the invention. A surface weight of between 1,400 g / m² has proven particularly advantageous. 2 and 1,800 g / m 2In an advantageous further development, the acoustically effective component has at least one through-opening and / or a stiffening section.

[0034] Through-holes serve to route other components, such as cables, pipes or lines, Bowden cables, or the like. For example, if the acoustically effective component is located on the bulkhead of the motor vehicle, this can have a through-hole through which the intermediate steering shaft extends, connecting the motor vehicle's steering column to the steering gear.

[0035] Stiffening sections serve to increase the rigidity of the acoustically effective component. This can be achieved, for example, through ribs or beads. Thanks to these stiffening structures, the dimensional stability of the acoustically effective component can be further improved.

[0036] In an advantageous embodiment, the geometry or the dimensions of both the recess formed in the absorber layer of the component are matched to the wavelength(s) of the frequency range in which increased acoustic absorption of the component is to be achieved.

[0037] In a first embodiment, the recess has substantially identical dimensions.

[0038] In an advantageous further development, it can be provided that the dimensions of the recesses are selected such that the acoustic resonance frequencies of the recesses are in the range of the frequencies to be expected in the motor vehicle and / or the frequencies of the vibrating surface.

[0039] Particularly preferably, the recesses interact in such a way that they as a whole have an acoustic resonance frequency that lies in the range of the frequencies to be expected in the motor vehicle and / or the frequencies of the vibrating surface.

[0040] In a second embodiment, the recesses have essentially identical geometry. In a third embodiment, at least two groups of recesses are provided. Within a group, the recesses have essentially identical dimensions and / or an identical geometry. However, the groups differ from one another in the dimensions and / or the geometry of their respective recess. This embodiment results in particularly diverse possibilities for specifically adjusting the acoustic properties of the component. Furthermore, it is conceivable and possible to combine a large number of groups of recesses, wherein the groups differ from one another in the dimensions and / or the geometry of the recesses. The arrangement of the recesses can also differ from group to group. In other words, the arrangement grid of the recesses can differ from group to group.

[0041] In a further embodiment, the recesses formed in the absorber layer are separated from one another by webs. In an advantageous embodiment of the invention, these webs form a coherent network. This can increase the dimensional stability of the component according to the invention.

[0042] Preferably, the webs may intersect. This can preferably occur at an angle of 90° or less.

[0043] Particularly preferably, at least two webs can intersect at a junction (crossing section), with the webs being raised in the area of ​​the junction. Thus, the web height is increased where they intersect. Thanks to the elevation at the junction, a significant improvement in the acoustic properties of the absorber layer is provided, making it significantly more effective.

[0044] Preferably, the webs can be provided with a pointed cross-section, i.e., the webs taper at their tip. The pointed webs can be combined with the raised portion at the junction point. This also leads to an improvement in the acoustic properties.

[0045] In an advantageous further development, it can be provided that the absorber layer is connectable or connected to the oscillating surface only in the area of ​​the nodes. Thus, the absorber layer only touches the oscillating surface at discrete points or sections, namely in the area of ​​the nodes, or is connected or coupled to it there. This can be implemented particularly easily if the webs are raised in the area of ​​the nodes.

[0046] In one embodiment, the webs between adjacent recesses have a substantially constant web width.

[0047] In an alternative embodiment, at least two groups of webs are formed in the absorber layer, each of which differs in its width. This is particularly advantageous for components that differ significantly in their spatial extent in two mutually perpendicular spatial directions.

[0048] Another alternative embodiment is characterized in that at the junction point of the at least two webs, the distance between the first and second sides of the webs is locally increased, so that an increased web width is created locally.

[0049] In a further embodiment of the invention, at least a portion of the recess formed in the absorber layer is arranged regularly, e.g. on a rectangular grid or a hexagonal grid.

[0050] In one embodiment of the invention, at least a portion, but preferably all, of the recesses formed in the absorber layer are designed as polygons, in particular as triangles or octagons. Alternatively, it has also proven advantageous if at least a portion, but preferably all, of the recesses formed in the absorber layer are designed as hemispherical or semi-ellipsoidal recesses. Combinations of both embodiments are also possible and can have acoustically advantageous properties.

[0051] In an advantageous development, it can be provided that an oscillating mass or oscillating mass layer is further arranged on the side of the mass layer facing away from the absorber layer. This oscillating mass or oscillating mass layer is connected to the mass layer, in particular formed integrally with it or materially connected to it. The oscillating mass preferably acts like a damper. This results in a spring-mass-oscillating mass structure. If the webs are additionally raised at their nodes, this results in a so-called 4-layer structure, which is formed by the oscillating mass, the mass layer, the absorber layer with the discrete recesses formed there, and a cavity arranged between the absorber layer and the oscillating surface. The cavity is formed because only the nodes of the absorber layer are in contact with the oscillating surface.

[0052] In an advantageous development, the vibrating mass and / or the mass layer can be provided with a mechanical structure that improves their acoustic properties. This mechanical structure can bring about a local adjustment (strengthening or weakening) of the stiffness. Thus, their behavior can be optimally adapted to the requirements.

[0053] These measures offer the advantage that the acoustically effective component has a reduced mass compared to the state of the art and at the same time enables more targeted insulation.

[0054] In an advantageous embodiment, the mass layer can be formed from a thermoformed PUR flake material. This PUR molded foam material is particularly easy to thermoform. It can also be provided that a PUR film is additionally incorporated into the mass layer to increase the flow resistance.

[0055] In an advantageous further development, it can be provided that the acoustically effective component is thermoformed.

[0056] In an advantageous development, the acoustically effective component is designed as a firewall insulation component, trunk insulation component, wheel house insulation component, door insulation component, floor assembly insulation component, or roof skin insulation component for a motor vehicle. This allows the acoustic properties inside the passenger compartment to be improved and, at the same time, the costs for manufacturing the motor vehicle to be reduced compared to the prior art. Furthermore, full recyclability is ensured. Furthermore, the object is achieved by a method according to the invention according to claim 21.

[0057] A method for producing an acoustically effective component for a motor vehicle is proposed, which comprises the following method steps: a) providing a molded foam tool which, in the closed state, forms a cavity which represents a negative of the component to be produced, and b) introducing a reactive mixture of polyol and isocyanate into the cavity to form a component made of PUR foam.

[0058] By varying the parameters of the fill quantity, closing pressure, and mold temperature, the mechanical and acoustic properties of the component can be specifically influenced. For example, the density of the resulting component can be adjusted and the surface finish can be influenced.

[0059] In an advantageous development of the method, the absorber layer and the mass layer can be processed by means of a shaping separation operation. A separation operation refers to various manufacturing processes in which the local material cohesion is eliminated, i.e., reduced overall, by changing the shape of the acoustically effective component. In particular, the separation operation can be a punching operation.

[0060] Thanks to this separation process, an acoustically effective component according to the invention can be manufactured with high precision and in a resource-efficient manner. The removed elements that are no longer needed can be fully recycled thanks to the purity of the PUR material.

[0061] A method according to the invention described above and its advantageous developments are preferably used to produce an acoustically effective component according to the invention and its advantageous developments described above. A further aspect of the invention provides a motor vehicle comprising a body having at least one vibrating surface and an acoustically effective component connected to the vibrating surface. According to the invention, the acoustically effective component is designed as an acoustically effective component according to the invention and / or is manufactured according to the method according to the invention.

[0062] Preferably, the vibrating surface is formed by a bulkhead (bulkhead), a floor assembly, a wheel house, a roof skin, a door or a trunk recess.

[0063] In an advantageous further development, the acoustically effective component is arranged on the inside relative to a passenger compartment of the motor vehicle, i.e. in the interior of the passenger compartment.

[0064] It is pointed out that the features of the specified developments and advantageous embodiments can be freely combined with one another within the scope of what is technically possible, even if this is not explicitly stated in the text. This applies in particular beyond the boundaries of the claim categories of device and method.

[0065] Further advantages and features of the acoustically effective component according to the invention emerge from the following exemplary embodiments, which are explained in more detail with reference to the figures (Figure = Fig.).

[0066] In these show:

[0067] Fig. 1 : a perspective view of a first embodiment of an acoustically effective component according to the invention,

[0068] Fig. 2: a plan view of the first embodiment and a sectional view along the section line AA,

[0069] Fig. 3: a perspective view of a second embodiment of an acoustically effective component according to the invention, Fig. 4: a plan view of the second embodiment and a

[0070] Sectional view along section line BB,

[0071] Fig. 5: a perspective view of a third embodiment of an acoustically effective component according to the invention,

[0072] Fig. 6: a plan view of the third embodiment and a sectional view along the section line CC,

[0073] Fig. 7: a perspective view of a fourth embodiment of an acoustically effective component according to the invention,

[0074] Fig. 8: a plan view of the fourth embodiment and a sectional view along the section line DD,

[0075] Fig. 9: a perspective view of a fifth embodiment of an acoustically effective component according to the invention,

[0076] Fig. 10: a plan view of the first embodiment and a sectional view along the section line EE,

[0077] Fig. 11 : a perspective view of a sixth embodiment of an acoustically effective component according to the invention,

[0078] Fig. 12: a plan view of the sixth embodiment and a

[0079] Sectional view along section line FF,

[0080] Fig. 13: a perspective view of a seventh embodiment of an acoustically effective component according to the invention,

[0081] Fig. 14: a plan view of the seventh embodiment and a sectional view along the section line GG,

[0082] Fig. 15: a perspective view of an eighth embodiment of an acoustically effective component according to the invention, Fig. 16: a plan view of the eighth embodiment and a sectional view along the section line HH,

[0083] Fig. 17: a perspective view of a ninth embodiment of an acoustically effective component according to the invention,

[0084] Fig. 18: a plan view of the ninth embodiment and a

[0085] Sectional view along section line II,

[0086] Fig. 19: a perspective view of a tenth embodiment of an acoustically effective component according to the invention,

[0087] Fig. 20: a plan view of the tenth embodiment and a

[0088] Sectional view along section line JJ,

[0089] Fig. 21 : a perspective view of an eleventh embodiment of an acoustically effective component according to the invention,

[0090] Fig. 22: a plan view of the eleventh embodiment and a sectional view along the section line KK,

[0091] Fig. 23: a perspective view of a twelfth embodiment of an acoustically effective component according to the invention,

[0092] Fig. 24: a plan view of the twelfth embodiment and a

[0093] Sectional view along section line LL,

[0094] Fig. 25: a perspective view of a thirteenth embodiment of an acoustically effective component according to the invention,

[0095] Fig. 26: a plan view of the first embodiment and a sectional view along the section line MM,

[0096] Fig. 27: a perspective view of a fourteenth embodiment of an acoustically effective component according to the invention, and Fig. 28: a plan view of the fourteenth embodiment and a

[0097] Sectional view along the section line NN,

[0098] Fig. 29: a schematic sectional view of a fifteenth embodiment.

[0099] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0100] All components 1 according to the invention shown in the various figures have a fundamentally identical structure and differ only in the design of their respective absorber layer 3. It should be noted that the basic square shape of the acoustically effective components shown is purely exemplary. In practice, components according to the invention are adapted in their two-dimensional or, if necessary, three-dimensional shape to the local conditions in the motor vehicle.

[0101] All components 1 are molded foam parts made of mixed-cell or closed-cell PUR foam. All components have a mass layer 2 and an absorber layer 3, with the mass layer 2 and absorber layer 3 being integral and made of the same material. Despite their integral construction, the mass layer 2 and the absorber layer 3 are shown as separate layers in the figures. However, this representation only serves to illustrate the inventive concept; there is no physical separation between layers 2 and 3.

[0102] The entire component 1 is manufactured in a foam mold, into which a reactive mixture of polyol and isocyanate is introduced in the appropriate mixing ratio. In the closed foam mold, the mixture reacts to form a closed-cell PUR foam, the density of which is typically between 100 and 200 kg / m 3The density may vary locally due to the local geometry of the foam molding tool, but this does not have to happen.

[0103] The foam molding tool represents a negative mold of the component to be produced according to the invention. Mass layer 2 and absorber layer 3 of the embodiments shown are produced in a single work step.

[0104] In an alternative process, mass layer 2 and absorber layer 3 are produced in separate steps. In this alternative process, one layer 2, 3 is advantageously foamed onto the other layer 3, 2. Using this alternative process, the acoustically relevant properties of the PUR foam can be specifically adjusted for each layer 2, 3. Relevant parameters include density, cell structure (closed-cell / mixed-cell), and surface texture.

[0105] The thickness of the mass layer 2 is 8 mm in all embodiments shown, the thickness of the absorber layer 3 is 15 mm in each case.

[0106] The basis weight of the mass layer 2 is approximately 1,600 g / m in all embodiments 2 , the surface weight of the absorber layer 3 is approximately 400 - 800 g / m 2 .

[0107] In the first exemplary embodiment according to Figures 1 and 2, box-shaped recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. In the plane of the absorber layer 3, they are square with an edge length A; their depth perpendicular to the plane of the absorber layer 3 is smaller than the edge length A. The edge length A is selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies expected in the motor vehicle.

[0108] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network.

[0109] The webs 5 between adjacent recesses 4 have a substantially constant web width.

[0110] In the first exemplary embodiment according to Figures 1 and 2, identical box-shaped recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. In the plane of the absorber layer 3, they are square with an edge length A; their depth perpendicular to the plane of the absorber layer 3 is smaller than the edge length A. The edge length A is selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies expected in a motor vehicle. The recesses 4 are arranged on a square grid in the plane of the absorption layer 3.

[0111] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network.

[0112] The webs 5 between adjacent recesses 4 have a substantially constant web width.

[0113] In the second embodiment shown in Figures 3 and 4, identical recesses 4 with a hexagonal base area are formed in the absorber layer 3, extending through the entire absorber layer 3. The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies expected in a motor vehicle. The recesses 4 are arranged in the plane of the absorption layer 3 on a hexagonal grid.

[0114] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network.

[0115] The webs 5 between adjacent recesses 4 have a substantially constant web width.

[0116] In the third exemplary embodiment, according to Figures 5 and 6, identical hemispherical recesses 4 with a circular base are formed in the absorber layer 3, extending through the entire absorber layer 3. The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies expected in a motor vehicle. The recesses 4 are arranged in the plane of the absorption layer 3 on a hexagonal grid. The recesses 4 formed in the absorber layer 3 are separated from one another by webs 5, which form a coherent network.

[0117] The webs 5 between adjacent recesses 4 have a variable web width.

[0118] In the fourth embodiment according to Figures 7 and 8, two groups of hemispherical recesses 4 with a circular base are formed in the absorber layer 3. The recesses 4 of the first group extend through the entire absorber layer 3. The recesses 4 of the second group extend through only a portion of the absorber layer 3.

[0119] A third group of recesses 4 is not hemispherical, but rather these recesses only represent spherical sections, which also extend only through a part of the absorber layer 3.

[0120] The dimensions of all recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0121] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network.

[0122] The webs 5 between adjacent recesses 4 have a variable web width.

[0123] In the fifth embodiment according to Figures 9 and 10, two groups of recesses 4 with hexagonal base areas are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses of the various groups differ in the respective dimensions of their hexagonal base areas.

[0124] The dimensions of the recesses 4 are selected so that the acoustic resonance frequencies of the recesses 4 are within the range of frequencies expected in a motor vehicle. The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network.

[0125] The webs 5 between adjacent recesses 4 have a locally varying web width.

[0126] In the sixth embodiment according to Figures 11 and 12, two groups of recesses 4 with rectangular base areas are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a square base area, while the recesses 4 of the second group have a rectangular base area.

[0127] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0128] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network.

[0129] The webs 5 between adjacent recesses 4 have a substantially constant width.

[0130] In the seventh embodiment according to Figures 13 and 14, two groups of recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a hexagonal base area, while the recesses 4 of the second group are hemispherical.

[0131] The recesses 4 are arranged on a hexagonal grid.

[0132] The dimensions of the recesses 4 are selected so that the acoustic resonance frequencies of the recesses 4 are within the range of frequencies expected in a motor vehicle. The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network. The width of the webs 5 varies locally.

[0133] In the eighth embodiment according to Figures 15 and 16, two groups of recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a square base, while the recesses 4 of the second group are hemispherical.

[0134] The recesses 4 are arranged on a square grid.

[0135] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0136] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network. The width of the webs 5 varies locally.

[0137] In the ninth embodiment according to Figures 17 and 18, two groups of recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a hexagonal base area, while the recesses 4 of the second group are hemispherical.

[0138] The recesses 4 are arranged on a square grid.

[0139] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0140] The recesses 4 formed in the absorber layer 3 are separated from one another by webs 5, which form a coherent network. The width of the webs 5 varies locally. In the tenth exemplary embodiment according to Figures 19 and 20, six groups of recesses 4 are formed in the absorber layer 3, some of which extend through the entire absorber layer 3. The recesses 4 of three groups have a hexagonal base area, while the recesses 4 of another three groups are hemispherical.

[0141] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0142] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network. The width of the webs 5 varies locally.

[0143] In the eleventh embodiment according to Figures 21 and 22, two groups of recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a hexagonal base area, while the recesses 4 of the second group have a base area in the shape of an equilateral triangle.

[0144] The recesses 4 of the first group are arranged on a hexagonal grid.

[0145] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0146] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network and have the same width everywhere.

[0147] In the twelfth embodiment according to Figures 23 and 24, two groups of recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a square base, while the recesses 4 of the second group have a round base. The recesses 4 of the first group are arranged on a square grid.

[0148] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0149] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network. The width of the webs 5 varies locally.

[0150] In the thirteenth embodiment according to Figures 25 and 26, two groups of recesses 4 are formed in the absorber layer 3, extending through the entire absorber layer 3. The recesses 4 of the first group have a square base and are arranged in the center of the component. The recesses 4 of the first group are arranged on a square grid.

[0151] The recesses 4 of the second group have a hexagonal base. They are arranged in regions of the component 1 that surround the central region in which recesses 4 of the first group are arranged.

[0152] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0153] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network. The width of the webs 5 varies locally.

[0154] In the fourteenth exemplary embodiment according to Figures 27 and 28, two groups of recesses 4 are formed in the absorber layer 3, which extend through the entire absorber layer 3. The recesses 4 of the first group have a square base area and are arranged in the center of the component. The recesses 4 of the first group are arranged on a square grid. The recesses 4 of the second group also have a square base area, and the dimensions of the recesses of the second group correspond to those of the first group. They are arranged in regions of the component 1 that surround the central region in which recesses 4 of the first group are arranged. In contrast to the recesses 4 of the first group, however, the recesses 4 of the second group are not arranged on a square grid, but rather irregularly.The density of the recesses 4 of the second group decreases from the center of the component 1 towards the edge.

[0155] The dimensions of the recesses 4 are selected such that the acoustic resonance frequencies of the recesses 4 are in the range of the frequencies to be expected in the motor vehicle.

[0156] The recesses 4 formed in the absorber layer 3 are separated from each other by webs 5, which form a coherent network. The width of the webs 5 varies locally.

[0157] Fig. 29 shows a schematic sectional view of an acoustically effective component 1 in a fifteenth exemplary embodiment. This acoustically effective component 1 comprises a mass layer 2 and an absorber layer 3 with recesses 4. On the side of the mass layer 2 facing away from the absorber layer, an oscillating mass in the form of an oscillating mass layer 6 is arranged. This oscillating mass layer 6 is connected to the mass layer 2. This results in a spring-mass-oscillating mass structure.

[0158] Reference symbol

[0159] 1 Acoustically effective component

[0160] 2 Mass layer 3 Absorber layer

[0161] 31 first page

[0162] 32 second page

[0163] 4 recess

[0164] 5 bridge 6 oscillating mass

Claims

Patent claims 1. Acoustically effective component (1) for a motor vehicle, comprising a mass layer (2) and an absorber layer (3) acting as a spring, wherein the absorber layer (3) has a first side (31) and a second side (32) opposite thereto, wherein the first side (31) is connected to the mass layer (2) and the second side (32) is designed for connection to a vibrating surface, wherein the mass layer (2) is formed from a PUR foam, characterized in that the PUR foam is mixed or closed-cell and the absorber layer (3) a) is formed in one piece with the mass layer (2) and from the same material, and b) has a plurality of recesses (4) which extend between the first side (31) and the second side (32) of the absorber layer (3).

2. Acoustically effective component (1) according to claim 1, characterized in that the PUR foam in the mass layer (2) and in the absorber layer (3) has substantially the same density.

3. Acoustically effective component (1) according to one of the preceding claims, characterized in that the recesses (4) have substantially identical dimensions.

4. Acoustically effective component (1) according to one of the preceding claims, characterized in that a first group of recesses (4) has substantially identical first dimensions and / or an identical first geometry and a second group of recesses (4) has substantially identical second dimensions and / or an identical second geometry, wherein the second dimensions are different from the first dimensions and / or the second geometry is different from the first geometry.

5. Acoustically effective component (1) according to one of the preceding claims, characterized in that the dimensions of the recess (4) are matched to the wavelength(s) of the frequency range in which increased acoustic absorption of the component (1) is to be achieved.

6. Acoustically effective component (1) according to one of the preceding claims, characterized in that the absorber layer (3) has a thickness between 5 and 30 mm, preferably between 7.5 and 20 mm.

7. Acoustically effective component (1) according to one of the preceding claims, characterized in that the mass layer (2) has a thickness between 1 and 20 mm, preferably between 2 and 15 mm.

8. Acoustically effective component (1) according to one of the preceding claims, characterized in that the thickness of the absorber layer (3) is at least 30% greater than the thickness of the mass layer (2), preferably at least 50% and particularly preferably at least 80% greater.

9. Acoustically effective component (1) according to one of the preceding claims, characterized in that the absorber layer (3) has a surface weight between 200 g / m 2 and 1,000 g / m 2 preferably between 400 g / m 2 and 800 g / m 2 .

10. Acoustically effective component (1) according to one of the preceding claims, characterized in that the mass layer (2) has a surface weight between 1,200 g / m 2 and 2,400 g / m 2 preferably between 1,400 g / m 2 and 1,800 g / m 2 .

11. Acoustically effective component (1) according to one of the preceding claims, characterized in that the recesses (4) formed in the absorber layer (3) are separated from one another by webs (5) which form a coherent network.

12. Acoustically effective component (1) according to one of the preceding claims, characterized in that the webs (5) between adjacent recesses (4) have a substantially constant web width.

13. Acoustically effective component (1) according to the preceding claim, characterized in that at least two groups of webs (5) are formed in the absorber layer, which differ in their web width.

14. Acoustically effective component (1) according to one of claims 11 to 13, characterized in that at least two webs (5) intersect at a node, wherein the webs (5) are raised in the region of the node.

15. Acoustically effective component (1) according to one of the preceding claims, characterized in that at least a subset of the recesses (4) formed in the absorber layer (3) is regularly arranged.

16. Acoustically effective component (1) according to one of the preceding claims, characterized in that at least a subset of the recesses (4) formed in the absorber layer (3) has the same geometric shape.

17. Acoustically effective component (1) according to one of the preceding claims, characterized in that at least a subset of the recesses (4) formed in the absorber layer (3) is designed as a polygon, in particular as a triangle to octagon.

18. Acoustically effective component (1) according to one of the preceding claims, characterized in that at least a subset of the recesses formed in the absorber layer (3) is designed as a hemispherical or semi-ellipsoidal recess.

19. Acoustically effective component (1) according to one of the preceding claims, characterized in that the mass layer is formed from a thermoformed PUR flake material.

20. Acoustically effective component (1) according to one of the preceding claims, characterized in that it is designed as a bulkhead insulation component, trunk insulation component, wheel house insulation component, door insulation component, floor assembly insulation component or as a roof skin insulation component for a motor vehicle.

21. A method for producing an acoustically effective component (1) for a motor vehicle, comprising the following method steps: a) providing a foam molding tool which, in the closed state, forms a cavity which represents a negative of the component (1) to be produced, and b) introducing a reactive mixture of polyol and isocyanate into the cavity to form a component made of PUR foam.

22. Method according to claim 21, characterized in that the component (1) is processed by means of a shaping separation operation.

23. Method according to one of claims 21 or 22, characterized in that the acoustically effective component (1) is designed according to one of claims 1 to 19.

24. Motor vehicle, comprising a body which has at least one vibrating surface, and an acoustically effective component (1) which is connected to the vibrating surface, characterized in that the acoustically effective component (1) is designed according to one of claims 1 to 20 and / or is manufactured according to one of claims 21 to 23.

25. Motor vehicle according to claim 24, characterized in that the oscillating surface is formed by a bulkhead, a floor assembly, a wheel house, a roof skin, a door or a trunk recess.

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