CH713133B1 - Sound absorbing element. - Google Patents

Abstract

A sound-absorbing element (1 ') is shown, comprising a carrier plate (12') with a sound-facing and a sound-facing surface, and a stabilization layer (11 ') arranged on the sound-facing surface of the carrier plate (12') with holes (microperforation) 111 '), wherein the carrier plate (12') has sound-facing openings (121 ') on the sound-facing surface and sound-facing openings (122') on the sound-facing surface, the sound-facing and sound-facing openings (121 '; 122') communicating via channels (123 ') are connected, the majority of the areas of the sound-facing openings (121') being larger than the areas of the sound-facing openings (122 '), and a proportion of the holes (111') forming the microperforation having a plurality of the openings (121 ') facing sound for the acoustically active effect, in particular for the formation of Helmholtz resonators and microabsorbers, k is communicatively connected.

Description

FIELD OF THE INVENTION

The present invention relates to a sound absorbing element and a method for producing a sound absorbing element.

BACKGROUND OF THE INVENTION

When furnishing publicly accessible rooms, especially in public buildings, but also in residential and furniture construction, the acoustics often play an important role. In the field of room acoustics, suitable sound-absorbing elements for cladding walls are to be provided, which are intended to ensure the acoustic properties of the room corresponding to the intended purpose. A number of requirements are typically imposed on the sound-absorbing elements, which e.g. good absorption values, low costs, sufficient mechanical stability, good aesthetic impression, simple installation, adequate fire protection properties, etc.

Sound-absorbing elements are known, which comprise a carrier plate with through holes, a perforated cover layer on the front of the carrier plate and a porous absorption layer, such as fleece, on the back of the carrier plate. The carrier plate and the top layer with the holes serve as sound-permeable layers for privacy and contact protection, the sound absorption being achieved by the absorption layer on the back of the carrier plate.

Another type of sound-absorbing elements are elements with Helmholtz resonators, in which the air mass in the holes reacts with the sound field and the incident sound energy is converted into kinetic energy of the air mass. Helmholtz resonators may not require a separate porous absorption layer, but can also be combined with one.

For aesthetic purposes, a better appearance of the sound-absorbing element can be achieved by a micro-perforated cover layer. Such is e.g. in EP 1876308, which shows a sound absorbing device having a plate-shaped core and first and second surfaces. A first coating and a second coating cover the first and second surfaces of the core, respectively. The first and the second coating are provided with holes arranged in a grid. The core is provided with a number of substantially parallel grooves which penetrate the two surfaces of the core. The coatings are glued to the surfaces by gluing, with some of the holes in the coatings opening into the grooves in the core. For improved static behavior, the core is designed to be groove-free along a frame-like edge region. A further improvement in the torsional rigidity is achieved in that the core has a number of struts which are also groove-free, so that the core is divided into several regions with grooves by the number of struts. In particular, the cover layers arranged on both sides also stabilize the core against bending and twisting.

WO2013 / 159240 shows a resonator with a cover layer with a microperforation; a carrier layer with a plurality of through openings, such as in particular bores or slots; and an intermediate layer which holds the cover layer at a distance from the carrier layer, the intermediate layer being designed to create a communicating connection to improve the sound-absorbing effect between the microperforation of the cover layer and openings of the carrier layer. The cover layer is in particular held at a stable distance from the support layer via the intermediate layer, a material connection such as an adhesive bond being provided between the cover layer and the intermediate layer and between the intermediate layer and the support layer. The intermediate layer is in particular made permeable to sound, so that there is an acoustically effective, communicating connection between the microperforation of the cover layer and the openings of the support layer and the sound-absorbing effect of the microperforation of the cover layer and the openings of the support layer is created.

PRESENTATION OF THE INVENTION

The various requirements for sound absorbing elements, such as e.g. good absorption values, low costs, sufficient mechanical stability, in particular torsional rigidity, good aesthetic impression, simple assembly, etc. are often difficult to achieve at the same time. E.g. For increased torsional rigidity, a frame without holes can be provided in the edge region of the support plate, but this reduces the absorption effect of the sound-absorbing element. In addition, such carrier plates are not suitable as modular standard elements which can be cut, since the frame can be cut or cut through when cutting, so that such carrier plates have to be produced as expensive one-off products for the respective application. Conversely, as large as possible or as large as possible openings in the carrier plate are generally desired, since through this the sound can be picked up, which is advantageous for the absorption effect, but has a disadvantageous effect on the mechanical stability. A reduction in the size of the openings in the carrier plate is disadvantageous for sound absorption, since that part of the incident sound that does not hit an opening is reflected again. In the case of a sound-absorbing element with microperforation, for example, the holes in the cover layer, which do not open into an opening in the carrier plate, do not contribute to sound absorption, since the sound passing through the holes is reflected again by the carrier plate. Adequate torsional rigidity without reducing the holes in the carrier plate or omitting some of the holes can e.g. As already mentioned above, this is achieved by applying a second cover layer with the same physical properties as the first cover layer to the front of the support plate on the back of the support plate. However, the second cover layer increases the costs due to the additional material and the additional manufacturing steps.

It is an object of the present invention to improve the prior art of sound absorbing elements.

[0009] This object is achieved by a sound-absorbing element and a method for producing a sound-absorbing element according to the independent claims. Exemplary and / or preferred embodiments are given in the dependent claims and in the present disclosure.

A sound-absorbing element according to the invention comprises a carrier plate with a sound-facing and a sound-facing surface, and a stabilization layer arranged on the sound-facing surface of the carrier plate with holes which form microperforations. The carrier plate has sound-facing openings on the sound-facing surface and sound-facing openings on the sound-facing surface, the sound-facing and sound-facing openings communicating via channels and the majority of the areas of the sound-facing openings being larger than the areas of the sound-facing openings. A portion of the holes forming the microperforation is communicatively connected to a plurality of the openings facing the sound for the acoustically active effect, in particular for the formation of Helmholtz resonators and microabsorbers.

The sound absorbing element is usually attached to the walls of the inside of a room so that the sound-facing surface of the support plate towards the wall and the sound-facing surface of the support plate are oriented towards the room. However, the sound absorbing element can e.g. also hanging on the ceiling of a room or free-standing, e.g. as a partition. The stabilization layer arranged on the surface of the carrier plate facing the sound, which is visible from a person who is in the room, serves both for stabilization and for the optical covering of the carrier plate.

The microperforation advantageously ensures both the permeability of the impinging sound and a good optical appearance, since the holes of the microperforation are only a short distance from the naked eye, e.g. below 50-60 cm are visible. In addition, the microperforation has the advantage that an optically disruptive moire effect can be avoided.

The sound-facing and sound-facing openings and the channels of the carrier plate are preferably generated in one step from the sound-facing surface of the carrier plate.

Preferably, the sound-facing and / or sound-facing surface of the carrier plate is planar in such a way that the channels each communicate with each other independently sound-facing openings with each other independently communicating sound-facing openings. This has an advantageous effect on the mechanical stability of the carrier plate.

The channels that connect the sound-facing and the sound-facing openings communicating generally have a varying profile in cross section perpendicular to the support plate and open on the sound-facing and the sound-facing surface in the respective sound-facing and sound-facing openings. This configuration of the channels and the sound-facing and sound-facing openings, wherein a majority of the areas of the sound-facing openings are larger than the areas of the sound-facing openings, has the advantage that the carrier plate meets both requirements for optimal sound absorption by providing sufficient open area as well as the sufficient mechanical stability, especially torsional stiffness, can meet. On the surface of the support surface facing the sound, the openings can be larger than in the case of openings of conventional support plates, in which the channels perpendicular to the support plate have a constant profile in cross section, without the mechanical stability of the support plate being reduced, since the loss of mechanical stability due to the smaller area of the openings on the surface of the carrier plate facing away from the sound is compensated. Conversely, the openings on the surface of the support surface facing away from the sound can be smaller than in the case of conventional openings without impairing the sound absorption of the sound-absorbing element, since the smaller openings facing away from the sound are compensated for by the larger surface area of the openings on the surface facing the sound. There is therefore the advantage that the area of the openings on the surface of the support plate facing the sound can be optimized for good sound absorption and the area of the openings on the surface facing away from the sound for sufficient mechanical stability.

In particular, the configuration of the channels and the sound-facing and sound-facing openings can ensure sufficient mechanical stability in such a way that an additional stabilizing edge without openings can be dispensed with and the openings can thus be arranged evenly distributed over the entire carrier plate. This is advantageous in that cutting the carrier plate when using the sound absorbing element does not generally lead to a reduction in the mechanical stability or a reduction in the absorption properties due to cuts which would cut away an edge or cut around an edge.

The configuration of the channels and the sound-facing and sound-facing openings also offers the advantage that a stabilizing layer on the sound-facing surface of the carrier plate is sufficient to provide sufficient mechanical stability, in particular torsional rigidity, of the sound-absorbing element. In the case of the conventional sound-absorbing elements, two stabilization layers are typically required for comparable areas of openings on the sound-facing surface of the carrier plate in order to ensure comparable mechanical stability. The reduction to a stabilization layer is advantageous for reducing the manufacturing costs. Since the microperforation-forming holes in the stabilization layer are generally formed by suitable perforation methods, such as e.g. Punching or e.g. with a suitable laser, the reduction to a stabilization layer can further reduce the manufacturing costs, which is a further advantage.

Due to the larger areas of the openings on the surface of the support plate facing the sound, the number of holes in the microperforation of the stabilization layer, which are communicating with openings on the surface facing the sound and can interact acoustically, can be increased without the mechanical stability of the To strongly affect the support plate, which has an optimal effect on sound absorption. This is advantageous in comparison to conventional sound-absorbing elements, in which an increase in the number of holes in the microperforation communicating with openings in the carrier plate while the microperforation remains the same is generally accompanied by an enlargement of the openings and thus a reduction in the mechanical stability.

Preferably, the channels form with the help of the wall of the room or a cover on the soundproof surface of the carrier plate and the holes of the microperforation of the stabilization layer Helmholtz resonators and microabsorbers with optimal sound absorption properties.

The mutual compensatory effect of the optimal sound absorption by the larger area of the sound-facing openings and the sufficient mechanical stability by the smaller area of the sound-facing openings enables the production of sound-absorbing elements, which in comparison to conventional sound-absorbing elements with comparable sound absorption and mechanical stability have a smaller thickness, which has a favorable effect on the production costs.

The channels can be axially symmetrical, preferably frustoconical, perpendicular to the carrier plate.

In the context of the present invention, axially symmetrical is to be understood to mean rotational symmetry with respect to an axis, the rotational symmetry also being able to include discrete rotations.

In one embodiment, the channels have circular cross sections with a tapering diameter along the channels.

The diameter of the channels advantageously decreases from the sound-facing surface of the carrier plate to the sound-facing surface of the carrier plate, which increases the mechanical stability without reducing the sound-facing open area. The diameter of the channels can taper continuously and / or in stages.

In embodiments with circular cross sections of the channels, the openings facing away from the sound preferably have diameters between 4 mm and 9 mm, more preferably between 5 mm and 8 mm, particularly preferably 6 mm.

In embodiments with circular cross sections of the channels, the openings facing the sound preferably have diameters between 6 mm and 10 mm, more preferably between 7 mm and 9 mm, particularly preferably 8 mm.

In one embodiment, the channels have countersinks, preferably cone countersinks, more preferably plane countersinks.

As an alternative or in addition, the channels are designed as stepped bores.

The depressions offer the advantage that the area of the openings facing the sound can be increased without severely impairing the mechanical stability of the carrier plate. The sound absorption properties of the sound absorbing element can be optimized in a flexible manner by a suitable choice of the dimensions of the countersinks and / or the stepped bores.

[0030] In certain embodiments, the countersinks have a depth of at least 2 mm. In further embodiments, the depressions have a depth between 2 mm and 6 mm. The depressions preferably have a depth of at least 1 2.5% of the thickness of the carrier plate, more preferably of at least 16.5% of the thickness of the carrier plate.

In a variant, the channels can be plane symmetrical, preferably truncated pyramid-shaped.

In one embodiment, the sound-facing and sound-facing openings are slit-shaped and the channels perpendicular to the support plate are plane-symmetrical, preferably in the form of a segment of a circle. This shape of the channels has the advantage that it can be produced in a simple and inexpensive manner by a milling machine, as will be explained below. The radius of the partial circle segment is preferably selected such that the Helmholtz resonator and microabsorber formed by the channel and the holes in the microperforation can provide sufficient sound absorption. In connection with the present invention, the section of a circle is understood to be the intersection between a circle segment and a rectangle lying on the base line of the circle segment. The channels in the form of a segment of a circle are understood to be three-dimensional bodies which have a thickness of the slot-shaped openings and a projection of a segment of the circle.

In certain embodiments, a number of channels with a circular cross section and a number of channels are plane symmetrical, preferably telecircle segment-shaped. Accordingly, a number of openings facing sound can be circular and a number of openings facing sound can be slit-shaped.

The channels are preferably arranged offset from one another. The offset arrangement of the channels in the carrier plate has the advantage that localized weak points in the carrier plate can be avoided and the general mechanical stability of the carrier plate can be increased. Since the impinging sound can generally be assumed to be uniform over a sound-absorbing element, the staggered arrangement of the channels has no negative effect on the sound-absorbing properties of the element.

[0035] In one embodiment, a nonwoven layer and / or a mineral fiber wool layer is arranged on the surface of the carrier plate facing away from the sound. This embodiment offers the advantage that the carrier plate and the stabilization layer, which, in particular due to the formation of the Helmholtz resonators and microabsorbers, are preferably reactive absorbers, can be combined with passive absorbers such as a fleece layer and / or a mineral fiber wool layer, and the sound absorption properties can be further optimized can.

In certain embodiments, the openings facing away from the sound have a length between 40 mm and 70 mm, more preferably 60 mm or preferably 50 mm, and have a width between 2 mm and 4.5 mm, more preferably between 2.5 mm and 4.5 mm preferably 3 mm or preferably 4 mm.

The microperforation-forming holes preferably occupy between 2.1% and 6.6%, further preferably 2.5%, particularly preferably 6%, further preferably 3% or 4.5%, of the area of the stabilization layer.

In certain embodiments, the openings facing away from the sound occupy between 10% and 20%, more preferably between 10% and 15%, further preferably 12% or more preferably 14%, of the area of the carrier plate.

In certain embodiments, the sound-facing openings occupy between 20% and 30%, more preferably 25% or more preferably 28.5%, of the area of the carrier plate.

In further embodiments, in particular in embodiments with channels with circular cross sections, the openings facing away from the sound take up between 20% and 50%, preferably between 23% and 47%, further preferably between 26% and 32%, of the area of the carrier plate.

In further embodiments, in particular in embodiments with channels with circular cross sections, the sound-facing openings take up between 30% and 60%, preferably between 40% and 55%, further preferably between 46% and 53%, of the area of the carrier plate.

The lengths and / or widths and / or diameters of the openings facing away from the sound and / or the openings facing the sound can be varied. Likewise, the distances between the openings facing away from the sound and / or the openings facing the sound can be varied along axes of the carrier plate. Varying the lengths and / or widths and / or diameters of the openings facing away from and / or the openings facing away from the sound and / or the distances between the openings facing away from the sound and / or the openings facing away from the sound enables different open areas of the sound-absorbing element to be produced. It is also possible, by varying the lengths and / or the widths and / or the diameters of the openings facing away from and / or facing the sound and / or the distances between the openings facing away from the sound and / or the openings facing away from the sound and / or the openings. or to vary the openings facing the sound on the surface of the carrier plate. The proportions of these parts can also be varied. However, it is also possible to vary the proportions so that the proportions of the proportions remain the same.

For example, a carrier plate can be equipped with sound-facing and sound-facing openings as follows: the width of the sound-facing openings is 4 mm, the length is 60 mm. The distance between the openings facing away from the sound along a transverse axis of the carrier plate is in each case 12 mm. With an expansion of the carrier plate along the transverse axis of 1000 mm, the number of rows along the transverse axis is 1000 mm / (12 mm + 4 mm) = 62.5. Along a longitudinal axis of the carrier plate, which is perpendicular to the transverse axis, the longitudinal and transverse axes of the carrier plate being parallel to the surface of the carrier plate facing away from and facing the sound, the openings facing away from the sound are each spaced apart by 120 mm. With an expansion of the carrier plate along the longitudinal axis of 1000 mm, the number of rows along the longitudinal axis is 1000 mm / 120 mm = 8.33. Along the longitudinal axis, the openings facing away from the sound have an overall dimension of 8.33 * 60 mm = 500 mm. The proportion of the area of the openings facing away from the sound on the area of the carrier plate is 12.5%. The proportion of the surface of the openings facing the sound on the surface of the carrier plate is 25%. The ratio of the proportions of the areas of the sound-facing to the sound-facing areas is 1: 2.

In a further example, a carrier plate can be equipped with sound-facing and sound-facing openings as follows: the width of the sound-facing openings is 3.50 mm, the length is 60 mm. The distance between the openings facing away from the sound along a transverse axis of the carrier plate is 10 mm in each case. If the carrier plate extends along the transverse axis by 1000 mm, the number of rows along the transverse axis is 1000 mm / (10 mm + 3.50 mm) = 74.07. Along a longitudinal axis of the carrier plate, which is perpendicular to the transverse axis, the longitudinal and transverse axes of the carrier plate being parallel to the surface of the carrier plate facing away from and facing the sound, the openings facing away from the sound are each spaced apart by 120 mm. With an expansion of the carrier plate along the longitudinal axis of 1000 mm, the number of rows along the longitudinal axis is 1000 mm / 120 mm = 8.33. Along the longitudinal axis, the openings facing away from the sound have an overall dimension of 8.33 * 60 mm = 500 mm. The proportion of the surface of the openings facing away from the sound on the surface of the carrier plate is 12.96%. The proportion of the area of the openings facing the sound on the area of the carrier plate is 25.93%. The ratio of the proportions of the areas of the sound-facing to the sound-facing areas is 1: 2.

In a further example, a carrier plate can be equipped with openings facing away from and facing away from the sound as follows: the width of the openings facing away from the sound is 3 mm, the length is 70 mm. The distance between the openings facing away from the sound along a transverse axis of the carrier plate is 10 mm in each case. With an expansion of the carrier plate along the transverse axis of 1000 mm, the number of rows along the transverse axis is 1000 mm / (10 mm + 3 mm) = 76.92. Along a longitudinal axis of the carrier plate which is perpendicular to the transverse axis, the longitudinal and transverse axes of the carrier plate being parallel to the surface of the carrier plate facing away from and facing the sound, the openings facing away from the sound are each spaced apart by 100 mm. With an expansion of the carrier plate along the longitudinal axis of 1000 mm, the number of rows along the longitudinal axis is 1000 mm / 100 mm = 10. Along the longitudinal axis, the openings facing away from the sound have an overall dimension of 10 * 70 mm = 700 mm. The proportion of the area of the openings facing away from the sound on the area of the carrier plate is 16.15%. The proportion of the surface of the openings facing the sound on the surface of the carrier plate is 23.08%. The ratio of the proportions of the areas of the sound-facing to the sound-facing areas is 1: 1.43.

In a further example, a carrier plate with channels with circular cross sections can be equipped with sound-facing and sound-facing openings as follows: The diameter of the sound-facing openings is 6 mm. The distance between the openings facing away from the sound along a transverse axis of the carrier plate is in each case 7 mm, successive openings facing away from the sound along the longitudinal axis of the carrier plate being offset by 7 mm in each case. Apertures that face one another and are offset from one another along the transverse axis thus have a distance of 14 mm. The diameter of the openings facing the sound is 8 mm. The proportion of the area of the openings facing away from the sound on the area of the carrier plate is 28.84%. The proportion of the openings facing the sound on the surface of the carrier plate is 51.26%. The ratio of the proportions of the areas of the sound-facing to the sound-facing areas is 1: 1.77. With an area of the carrier plate of 1 m 2, the number of holes is 10,204.

Preferably, the ratio of the sum of the areas of the sound-facing openings and the sum of the areas of the sound-facing openings of the carrier plate is x: 1, where x is preferably between 1.1 and 2.5, more preferably between 1.4 and 2.2, more preferably 1.77 or more preferably 2 is.

In one embodiment, at least one edge of the sound-absorbing element has a first connection element and at least one further edge of the element has a second connection element, so that the element can be connected to a further element via the first and the second connection element. The first connection element can be a comb and the second connection element can be a groove, so that the element can be connected to a further element by a comb-groove connection. Optionally, the connection elements can be designed as click-lock elements, so that the sound-absorbing elements can be connected to one another by a click-lock mechanism. This has the advantage that the sound-absorbing element can be a modular element which, depending on requirements, e.g. can be assembled into a wall cladding without having to cut the elements large. The comb-groove connection or the click lock mechanism also offer the advantage that the sound-absorbing elements can be installed in a simple and quick manner. The connection elements are preferably designed such that the joints between the sound-absorbing elements are at a sufficient distance, e.g. larger than 2 m, are unrecognizable to the eye. This has the advantage that from a sufficient distance, a cladding with the sound-absorbing elements can appear optically seamless.

[0049] In one embodiment, the stabilization layer comprises a veneer.

[0050] Alternatively or in addition, the stabilization layer comprises a synthetic resin.

As an alternative or in addition, the stabilization layer comprises a lacquer.

As an alternative or in addition, the stabilization layer comprises a laminate. The laminate can be a Continuous Pressure Laminate (CPL).

Such materials offer the advantage that the stabilization layer can be designed to be optically appealing.

The microperforation-forming holes preferably have a diameter between 250 μm and 550 μm, more preferably 300 μm or preferably 500 μm. This dimensioning offers the advantage that the holes forming the microperforation are both acoustically active and small enough that they are at a sufficient distance, e.g. larger than 50-60 cm, are unrecognizable to the eye and can therefore form a visually appealing surface.

In one embodiment, the carrier plate consists of pressboard.

In one embodiment, the carrier plate consists of gypsum fiber.

[0057] These materials have the advantage that they are easy to work with and inexpensive.

In one embodiment, the carrier plate consists of wood fibers. For example, the carrier plate can be designed as a medium-density fiberboard (MDF) or as a high-density fiberboard (HDF).

The invention further relates to a method for producing a sound-absorbing element according to the present disclosure, characterized in that the sound-facing and sound-facing openings and the channels are each generated in one step from the sound-facing surface of the carrier plate.

This offers the advantage that the manufacturing process can be simplified and the manufacturing costs can be reduced.

In one embodiment of the method, the sound-facing and sound-facing openings and the channels are milled into the carrier plate by a milling machine, the internal milling shape of the channels at least partially corresponding to the milling blade and the openings and channels by a consecutive up / down and / or longitudinal movement of the milling blade and / or the sound absorbing element can be milled.

An exemplary method with a milling machine for producing a sound-absorbing element is shown as follows: milling blades are each arranged on a shaft or a plurality of mutually spaced shafts of a milling machine. The carrier plate to be machined is guided in the feed direction, past the shaft or the shafts that are perpendicular to the feed direction and are aligned parallel to the surface of the carrier plate. The carrier plate is brought into the area of the shaft (s) or the milling blades by means of a feed device (not shown). These are in a parked position. These can then be delivered, whereby the openings of the carrier plate are milled out. Then they are brought back into the parked position and the carrier plate is advanced by one step. By repeating this process, the entire carrier plate can be provided with openings.

Optionally, the milling blades can be arranged in a method with a milling machine with a shaft at twice the distance between the slot-shaped openings of the carrier plate. The openings can then be milled with the milling blades of this one shaft offset from one another.

In embodiments with channels with circular cross sections, the sound-facing and sound-facing openings and the channels are preferably drilled. The depressions are preferably generated in the same step as the channels.

LIST OF FIGURES

Embodiments of the invention are explained in more detail with reference to the following figures and the associated descriptions. Show it: <tb> Fig. 1 <SEP> is a perspective view of an embodiment of a sound absorbing element from the side facing the sound; <tb> Fig. 2 <SEP> is a perspective view of the sound absorbing element from FIG. 1 from the side facing away from the sound; <tb> Fig. 3 <SEP> is a sectional view of the sound absorbing element along the section line A-A in Fig. 1; <tb> Fig. 4 <SEP> is a sectional view of the sound absorbing element along the section line B-B in Fig. 1; <tb> Fig. 5 <SEP> is a perspective view of a further embodiment of a sound absorbing element from the side facing the sound; <tb> Fig. 6 <SEP> a representation of an arrangement of sound-facing and sound-facing openings of a further embodiment of the carrier plate from the sound-facing side; <tb> Fig. 7 <SEP> is a perspective view of a further embodiment of a sound-absorbing element from the side facing the sound.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In order to illustrate the invention, preferred embodiments are described in more detail with reference to the figures.

Figure 1 shows a perspective view of an embodiment of a sound-absorbing element 1 from the sound-facing side with a view of the sound-facing surface of the carrier plate 12. The sound-absorbing element comprises a stabilizing layer 11 and a carrier plate 12. Around the sound-facing surface of the carrier plate 12 and To show the openings 121 facing the sound, part of the stabilization layer 11 is shown schematically cut out in the figure. The stabilizing layer 11 is on the surface of the carrier plate 12 facing the sound, e.g. by sticking. The rear surface facing away from the sound is not visible in the figure. The carrier plate 12 has sound-facing openings 121 on the sound-facing surface and sound-facing openings 122 on the sound-facing surface, which are communicatively connected by channels 123. The area of the openings 121 facing the sound is larger than the area of the openings 122 facing away from the sound, so that in the perspective view shown, the side walls 1231 of the channels 123 are visible from the side facing the sound. The stabilization layer 11 has holes 111 which form microperforations. A portion of the holes 111 is communicatively connected to the openings 121 facing the sound. The sound absorbing element 1 shown is designed to be open on the surface facing away from the sound, i.e. no additional layer is applied to the surface of the carrier plate 12 facing away from the sound. When a wall is clad with the sound-absorbing element 1 shown, the wall closes the opening 122 facing away from the sound, so that Helmholtz resonators and microabsorbers are formed by the wall, the opening 122 facing away from the sound, the channel 123, the opening 121 facing the sound and the holes 111. The openings 121 facing the sound are arranged offset from one another, which has a favorable effect on the mechanical stability of the carrier plate 12. The stabilization layer 11 is e.g. made of plywood. The carrier plate 12 is e.g. a plasterboard. The sound-facing and sound-facing openings 121, 122 and the channels 123 are milled into the carrier plate 12 with the aid of a milling machine.

FIG. 2 shows a perspective view of the sound-absorbing element 1 from FIG. 1 from the side facing away from the sound, with a view of the surface of the carrier plate 12 facing away from the sound. In this view, the openings 122 facing away from the sound are clearly visible. The openings 121 facing the sound are covered by the stabilization layer 11, the holes forming the microperforation not being shown in this figure. A longitudinal edge of the sound-absorbing element 1 is shown cut in such a way that the channels 123 in the form of a segment of a circle are visible. The sound-facing openings 121 are communicatively connected to the sound-facing openings 122 through the channels 123, the partial circle shape of the channels 123 ensuring that the area of the sound-facing openings 121 is larger than the area of the sound-facing openings 122.

Figure 3 shows a sectional view of the sound absorbing element 1 along the section line AA in Fig. 1. In the direction shown, the sides of the channels 123 are perpendicular to the support plate 12 and communicatively connect the sound-facing openings 121 with the sound-facing openings 122. The stabilization layer 11 is not shown in the figure for the sake of simplicity. Because of the channels 123 in the form of a segment of a circle, which are arranged offset, every second channel 123 through the carrier plate 12 is shown continuously in this sectional illustration.

FIG. 4 shows a sectional illustration of the sound-absorbing element 1 along the section line B-B in FIG. 1. In the direction shown, it can be seen that the channels 123 are designed in the shape of a segment of a circle. The pitch circle segments correspond to the shapes of the milling blades of the milling machine, which immerse in the carrier plate 12 during milling such that the channels 123 shown are milled out of the carrier plate 12 with the sound-facing and sound-facing openings 121, 122. Furthermore, it can be seen that the shape of the channels 123 shown, which communicatively connect the sound-facing and sound-facing openings 121, 122, enables the configuration in which the area of the sound-facing openings 121 is larger than the area of the sound-facing openings 122.

FIG. 5 shows a perspective view of a further embodiment of a sound-absorbing element 1 'from the side facing the sound. The sound-absorbing element 1 'comprises a stabilization layer 11' and a carrier plate 12 '. In order to show the surface of the support plate 12 'facing the sound and the openings 121' facing the sound, part of the stabilization layer 11 'is shown schematically cut out in the figure. The stabilization layer 11 'is on the sound-facing surface of the carrier plate 12', e.g. by sticking. The carrier plate 12 'has sound-facing openings 121' on the sound-facing surface and sound-facing openings 122 'on the sound-facing surface, which are communicatively connected by channels 123'. The channels 123 'are designed as bores with circular cross sections and a tapering diameter along the channels 123'. The tapering diameters along the channels 123 'are achieved by depressions 124', which emanate from the openings 121 'facing the sound and open into cylindrical sections of the channels 123'. In order to better illustrate the channels 123 'and the openings 122' facing away from the sound, the carrier plate 12 'is shown cut at a corner, so that two channels 123' are shown cut in the direction along the channels 123 '. In the embodiment shown, the countersinks 124 'are designed as cone countersinks. In order to better show the depressions 124 'in the figure, the carrier plate 12' is shown cut out partially in stages at the height of the depressions 124 '. The depressions 124 'result in the areas of the openings 121' facing the sound being larger than the areas of the openings 122 'facing away from the sound. The stabilization layer 11' has holes 111 'which form microperforations. A portion of the holes 111 'is communicatively connected to the openings 121' facing the sound. The sound absorbing element 1 'shown is shown open on the surface facing away from the sound, i.e. no additional layer is applied to the surface of the carrier plate 12 'facing away from the sound. When a wall is clad with the sound-absorbing element 1 'shown, the wall closes the openings 122' facing away from the sound, so that through the wall, the opening 122 'facing away from the sound, the channel 123', the opening 121 'facing the sound and the holes 111' Helmholtz- Resonators and microabsorbers are formed. The sound-facing openings 121 ', the channels 123' and the sound-facing openings 122 'are arranged across the carrier plate 12' in a regular, non-offset grid, i.e. Successive openings 121 'facing sound or openings 122' facing away from sound lie in each case on the same transverse axis or longitudinal axis of the carrier plate 12 '.

6 shows a representation of an arrangement of sound-facing openings 121 "and sound-facing openings 122" and channels 123 "of a further embodiment of the carrier plate from the sound-facing side. The sound-facing openings 121" and the sound-facing openings 122 "are through channels 123 "communicatively connected. Countersinks 124 "emanate from the sound-facing openings 121", each of which opens into cylindrical sections of the channels 123 ". The sound-facing openings 121" are circular with a diameter d. The openings 122 "facing away from the sound and the channels 123" are circular in shape with a diameter d '. Due to the depressions 124 "it is achieved that d> d 'and therefore the areas of the sound-facing openings 121" are each larger than the areas of the sound-facing openings 122 ". The sound-facing openings 121" and with them the channels 123 "and the sound-facing Openings 122 "are arranged offset from one another in a grid. Along the transverse direction x of the carrier plate, a series of sound-facing openings 121 "are arranged at intervals a to one another, with a further sound-sensitive opening 121" by a. Between two sound-facing openings 121 ", which are arranged at a distance a from each other in the x-direction '/ 2 is arranged offset in the longitudinal direction y of the carrier plate. Along the longitudinal direction y, the openings 121 "facing the sound are arranged at a distance a' from one another. In the embodiment shown, a = a '.

FIG. 7 shows a perspective view of a further embodiment of a sound-absorbing element 1 "'from the side facing the sound. The sound-absorbing element 1'" comprises a stabilizing layer 11 '"and a carrier plate 12"'. In order to show the surface of the support plate 12 "'facing the sound and the openings 121'" facing the sound, part of the stabilization layer 11 '"is shown schematically cut out in the figure. The stabilization layer 11"' is on the surface of the support plate 12 "'facing the sound, The carrier plate 12 '"has sound-facing openings 121"' on the sound-facing surface and sound-facing openings 122 '"on the sound-facing surface, which are communicatively connected by channels 123'". The channels 123 "'are as Stepped bores 124 '"with circular cross sections and a tapering diameter along the channels 123'" are formed. The tapering diameters along the channels 123 "'are achieved through the stepped bores 124" ", which each divide the channels into two cylindrical sections with different diameters, the cylindrical section which opens into the sound-facing openings 121" "having a larger diameter has as the cylindrical section, which opens into the sound-facing openings 122 ". In order to better illustrate the channels 123 '"and the openings facing away from the sound 122"', the support plate 12 "'is shown cut at a corner, so that two channels 123"' are shown cut in the direction along the channels 123 '" In order to better illustrate the stepped bore 124 '", the support plate 12"' is shown cut out partially in a stepped manner. The stepped holes 124 '"result in the areas of the sound-facing openings 121'" each being larger than the areas of the sound-facing openings 122 '", The stabilization layer 11 "'has holes 111"' which form microperforations. A portion of the holes 111 '"is communicatively connected to the openings 121'" facing the sound.

Claims (21)

1. Sound absorbing element (1, 1 ', 1' ''), comprising a carrier plate (12, 12 ', 12 "') with a sound-facing and a sound-facing surface, and one on the sound-facing surface of the carrier plate (12, 12 ' , 12 "') arranged stabilization layer (11, 11', 11" ') with holes (111, 111', 111 '' ') which form a microperforation, the support plate (12, 12', 12 "') having openings facing the sound ( 121, 121 ', 121 ", 121'") on the surface facing the sound and openings (122, 122 ', 122 ", 122"') facing away from the sound, the openings facing away from the sound (121, 121 ', 121 ", 121 '"; 122, 122', 122 ", 122" ') communicating via channels (123, 123', 123 ", 123 '"), the majority of the surfaces of the sound-facing openings (121, 121 ', 121 ", 121'") is larger than the areas of the openings (122, 122 ', 122 ", 122"') facing away from the sound, and a portion of the holes forming the microperforation it (111, 111 ', 111 "') is communicatively connected to a plurality of the openings (121, 121 ', 121", 121' "facing the sound for the acoustically active effect, in particular for the formation of Helmholtz resonators and microabsorbers. 2. Sound-absorbing element (1, 1 ', 1' ") according to claim 1, characterized in that the channels (123, 123 ', 123", 123 "') perpendicular to the support plate (12, 12 ', 12"') axially symmetrical, preferably frustoconical, or plane symmetrical, preferably truncated pyramid. 3. Sound absorbing element (1 ', 1 "') according to claim 1 or 2, characterized in that the channels (123 '. 123", 123' ") circular cross-sections with a along the channels (123 ', 123", 123 "') have a tapering diameter (d, d'). 4. Sound absorbing element (1 ', 1 "') according to claim 3, characterized in that the sound-facing openings (121 ', 121", 121' ") diameter between 6 mm and 10 mm, preferably between 7 mm and 9 mm, particularly preferably have of 8 mm. 5. Sound-absorbing element (1) according to claim 1, characterized in that the sound-facing and sound-facing openings (121; 122) are slit-shaped and the channels (123) perpendicular to the carrier plate (12) are plane symmetrical, preferably part-circle segment-shaped. 6. Sound-absorbing element (1) according to claim 1 or 5, characterized in that the sound-facing openings (122) have a length between 40 mm and 70 mm, preferably 60 mm, more preferably 50 mm, and a width between 2 mm and 4.5 mm , preferably between 2.5 mm and 4.5 mm, more preferably 3 mm, more preferably 4 mm. 7. Sound-absorbing element (1 ', 1' '') according to one of the preceding claims, characterized in that the channels (123 ', 123 ", 123"') countersinks (124, 124 "), preferably conical countersinks, more preferably counterbores , have or are designed as stepped bores (124 "'). 8. Sound-absorbing element (1) according to one of the preceding claims, characterized in that the channels (123, 123 ") are arranged offset to one another 9. Sound-absorbing element according to one of the preceding claims, characterized in that a fleece layer and / or a mineral fiber wool layer is arranged on the surface of the carrier plate facing away from the sound. 10. Sound-absorbing element (1, 1 ', 1 "') according to one of the preceding claims, characterized in that the microperforation holes (111, 111 ', 111"') between 2.1% and 6.6%, preferably 2.5%, 3rd %, 4.5% or 6% of the area of the stabilization layer (11, 11 ', 11 "'). 11. Sound-absorbing element (1, 1 ', 1 "') according to one of the preceding claims, characterized in that the openings (122, 122 ', 122", 122 "') facing away from the sound are between 10% and 20%, preferably between 10 % and 15%, more preferably 12% or 14%, of the area of the carrier plate (12, 12 ', 12 "'). 12. Sound-absorbing element (1, 1 ', 1 "') according to one of the preceding claims, characterized in that the sound-facing openings (121, 121 ', 121", 121 "') between 20% and 30%, preferably 25% or 28.5% of the area of the carrier plate (12, 12 ', 12 "'). 13. Sound absorbing element (1, 1 ', 1 "') according to one of the claims 1 to 10, characterized in that the sound-facing openings (122, 122 '. 122", 122' ") between 20% and 50%, preferably between 23% and 47%, more preferably between 26% and 32% of the area of the carrier plate (12, 12 ', 12' ''). 14. Sound-absorbing element (1, 1 ', 1 "') according to one of the claims 1 to 10 or 13, characterized in that the sound-facing openings (121, 121 ', 121", 121' ") between 30% and 60% , preferably between 40% and 55%, more preferably between 46% and 53% of the area of the carrier plate (12, 12 ', 12 "'). 15. Sound-absorbing element (1, 1 ', 1 "') according to any one of the preceding claims, characterized in that the ratio of the sum of the areas of the sound-facing openings (121, 121 ', 121", 121 "') and the sum of Areas of the openings (122, 122 ', 122 ", 122"') of the carrier plate (12, 12 ', 12 "') facing away from the sound is x: 1, where x is between 1.1 and 2.5, preferably between 1.4 and 2.2, more preferably 1.77 or more preferably 2. 16. Sound-absorbing element according to one of the preceding claims, characterized in that at least one edge of the sound-absorbing element has a first connection element and at least one further edge of the element has a second connection element, so that the element with a further element via the first and the second connection element is connectable. 17. Sound-absorbing element (1, 1 ', 1 "') according to one of the preceding claims, characterized in that the stabilization layer (11, 11 ', 11"') is a veneer wood and / or synthetic resin and / or lacquer and / or a Laminate, preferably a Continuous Pressure Laminate, i.e. H. CPL. 18. Sound-absorbing element (1, 1 ', 1 "') according to one of the preceding claims, characterized in that the microperforation holes (111, 11 1 ', 111'") have a diameter between 250 microns and 550 microns, preferably 300 µm, more preferably 500 µm. 19. Sound-absorbing element (1, 1 ', 1' ") according to one of the preceding claims, characterized in that the carrier plate (12, 12 ', 12' '') made of pressboard or gypsum fiber or wood fibers, preferably a medium density fiberboard, ie MDF, or forming a high density fiberboard, ie HDF. 20. A method for producing a sound-absorbing element (1, 1 ', 1 "') according to one of the preceding claims, characterized in that the sound-facing and sound-facing openings (121, 121 ', 121", 121 "'; 122, 122 ' , 122 ", 122 '") and the channels (123, 123', 123 ", 123 '") are each generated in one step from the surface of the carrier plate (12, 12', 12 '' ') facing the sound. 21. The method according to claim 20, characterized in that the sound-facing and sound-facing openings (121, 122) and the channels (123) are milled into the carrier plate by a milling machine, the internal milling shape of the channels (123) at least partially corresponding to the milling blade and the openings (121, 122) and channels (123) are milled by a consecutive up / down and / or longitudinal movement of the milling blade and / or the sound-absorbing element (1).