WO2010052195A1

WO2010052195A1 - Device for absorbing structure-borne sound

Info

Publication number: WO2010052195A1
Application number: PCT/EP2009/064479
Authority: WO
Inventors: Hans A. HÄRLE; Waldemar Kiener
Original assignee: Poroson Gmbh
Priority date: 2008-11-05
Filing date: 2009-11-03
Publication date: 2010-05-14
Also published as: EP2352933A1; DE102008056031A1

Abstract

A device for absorbing structure-borne, hydraulic and/or airborne sound comprises a body (1) capable of being set into oscillatory motion through sound waves, and a fabric (7) comprising warp threads and weft threads and pores formed between the warp threads and the weft threads and comprising friction points formed at the points of contact of the warp threads with the weft threads. The fabric (7) is attached to the body (1) in such a way that when sound impinges on the body (1), friction takes place between the fabric and the body.

Description

Device for absorbing structure-borne noise

The invention relates to a device for absorbing body, hydro and / or airborne sound on a vibratable body.

A major problem in the design of machine housings, and the like serving for the storage of rotating components casing which are exposed to a high temperature, in particular of more than 5O ⁰ C, is the damping of structure-borne noise, that of which a force and velocity excitation via structural members goes out, transmits to the housing and leads to a strong sound radiation in both air and in liquids. Since the transmitted, for example, by a wave on the storage of the housing structure-borne noise with conventional measures hardly get to grips with, very complex structures for absorption or for the insulation of sound development are often used.

Also by liquid or gas streams, it can come to the walls of containers, machines or the like to generate loud noises, which are often very difficult to insulate or absorb.

It is therefore an object of the present invention to provide a device for absorbing body, hydro and airborne sound, which allows the simplest possible means effective absorption of structure-borne noise. According to the invention, this object is achieved by the features mentioned in claim 1.

By a sound or a force or speed excitation of a body arise bending waves, which deform the body, albeit only to a very small extent, and thus lead to the sound radiation through the body. The fabric according to the invention with the warp wires and the weft wires and the pores formed therebetween, and in particular the friction points at which friction occurs within the fabric, together with the friction between the fabric and the fabric resulting from the attachment of the fabric to the body Body, a high attenuation of this structure-borne sound. Furthermore, a so-called acoustic short circuit results on the surface of the fabric provided according to the invention, in which the pressure waves excited by the vibrations are compensated within and on the surface of the fabric.

The dissipation factor in the fabric, which is partly responsible for the damping, is caused by friction at the contact points of the wires. Bending of the fabric results in shear and expansion forces. Vibrations in the tissue are converted into heat by friction.

Further advantages of the device according to the invention are its small thickness, high specific mass and high temperature resistance.

In a very advantageous development of the invention can be provided that the tissue is attached by means of an adhesive layer on the body. Through such an adhesion layer is a high loss factor for the by the vibrations of the Body produced body sound, which leads to a further damping.

A very good sound-insulating effect is achieved if, in an advantageous development of the invention, the adhesion layer is an adhesive. Such an adhesive may, in particular, be in liquid or pasty form and be applied very simply to the surface of the wall of the body or else to the tissue, so that the tissue can be attached to the body in a very simple manner.

Alternatively, it can also be provided that the adhesion layer is provided with an adhesive layer plastic film. This represents a further simplification with regard to the attachment of the fabric to the body, in particular for very smooth and flat surfaces.

Furthermore, it can be provided that the adhesion layer is made of silicone. It has been found that such silicone-based adhesive layers produce a particularly high loss factor.

As an alternative to the connection of the tissue to the body by means of the adhesion layer, the tissue can be attached to the body by means of welding, screwing, riveting or pressing.

An additional stiffening and a higher loss factor is obtained if on the side facing away from the body of the fabric, a smooth surface having sheet metal is attached. -A -

It can be provided that the sheet having a smooth surface is attached to the fabric by means of an adhesion layer. Such an adhesion layer increases the loss factor generated by the device according to the invention.

In order to achieve a lower sound emission or structure-borne sound attenuation in another way or in addition to the aforementioned further developments, it can further be provided that a plurality of layers of the fabric are provided.

In order to achieve an even higher loss factor within the device, it is furthermore advantageous if the individual layers of the fabric are connected to one another by means of respective adhesion layers.

In a further advantageous embodiment of the invention, a plurality of material layers may be provided, wherein the modulus of elasticity of the material layers increases, the farther the material layer is removed from the wall of the body. Such an increase in the modulus of elasticity of the material layers further away from the body results in further improved damping.

A particularly advantageous application of the device according to the invention results when the body is designed as a housing, in particular as a housing in which a shaft is rotatably mounted.

Alternatively, an application is conceivable in which the body is designed as a structure arranged in a liquid or in a gas stream, in particular as a plate, since the above-described effect with respect to the absorption of structure-borne noise also takes place in liquids or gases. Further advantageous embodiments and modifications of the invention will become apparent from the remaining dependent claims. Embodiments of the invention are shown in principle with reference to the drawings.

It shows:

1 shows a first embodiment of the device according to the invention for absorbing structure-borne noise on a housing.

Fig. 2 is a plan view of the fabric of the device according to the invention;

Fig. 3 is a section along the line III-III of Fig. 2;

Fig. 4 is a section along the line IV-IV of Fig. 2;

5 shows a second embodiment of the device according to the invention;

6 shows a third embodiment of the device according to the invention;

7 shows a fourth embodiment of the device according to the invention;

8 shows a section through the tissue of the device according to the invention;

9 is an enlarged view to illustrate the running in the tissue acoustic short circuit process. 10 is a further enlarged view to illustrate the running in the tissue friction process.

FIG. 11 shows a further enlarged representation to clarify the acoustic short circuit process taking place in the fabric; FIG.

12 shows a further embodiment of the device according to the invention for absorbing structure-borne noise with a plate arranged in a liquid; and

13 shows a further embodiment of the device according to the invention for absorbing structure-borne noise with a plate arranged in a gas flow.

Fig. 1 shows in a very schematic manner a part of a body 1 forming a housing 1, in which a shaft 2 is rotatably mounted. For supporting the shaft 2 are respective bearings 3, which may be formed in a conventional manner and housed in the present case in respective outer walls 4 of the housing 1. The two outer walls 4, in which the bearings 3 are connected to another outer wall 5 with each other. The illustrated construction of the housing 1, however, is to be regarded as purely exemplary and it would of course also be possible to mount the bearings 3 in the housing 1 in a different manner. The housing 1 is preferably a cast housing, in particular a gear housing. However, the housing 1 may also be a welded, bolted, or otherwise connected construction. By vibrations of the shaft 2, which are transmitted via the bearings 3 on the walls 4 and 5 of the housing 1, formed on the housing 1 structure-borne sound in the form of bending waves, which radiates strong airborne sound depending on the frequency and amplitude of the vibration. For the absorption of structure-borne noise is a device 6, which has in its simplest, shown in Fig. 1 embodiment, a fabric 7, which is attached by means of an adhesive layer 8 in the present case to the wall 5 of the housing 1.

The adhesion layer 8 may be an adhesive, that is to say in particular a liquid or viscous adhesive or else an adhesive film, ie a plastic film provided with an adhesive layer, or a special damping film with an adhesive coating and is preferably produced on the basis of silicone.

Alternatively to the use of the adhesion layer 8, the fabric 7 can also be attached to the housing 1 by means of welding (in particular spot welding), screwing, riveting or pressing.

In any case, the fabric 7 is attached to the housing 1 in such a way that, when the housing 1 is acted upon by the sound, friction takes place within the fabric 7 and between the fabric 7 and the housing 1.

In Fig. 2 is a plan view of an embodiment of the fabric 7 is shown. This has warp wires 9 and substantially perpendicular to the warp wires 9 extending weft wires 10. Furthermore, the fabric 7 has a plurality of pores IIa, which are located between the warp wires 9 and the weft wires 10, and friction surfaces or friction points IIb, which adjoin the Touch points of the warp wires 9 with the weft wires 10 result. The pores IIa and the friction points IIb can be seen better in the illustration according to FIG. Due to the friction at the friction points IIb between the warp wires 9 and the weft wires 10 results in a damping of the sound causing friction.

Compared to the use of a steel plate as a sound damping element, the fabric 7 or the entire device 6 has a loss factor of up to more than 100 times, depending on the design of the same, wherein a higher loss factor leads to a lower sound level.

The fabric 7 is preferably made by a per se known weaving method by weaving the warp wires 9 and the weft wires 10 together. For this purpose, a variety of weaving methods can be used. Optionally, it is also possible to treat the fabric 7 galvanic.

The fabric 7 shown in Figures 2, 3 and 4 was rolled after weaving, resulting in a substantial reduction in the thickness thereof. As an alternative to rolling, it is also possible to reduce the thickness of the fabric 7 in a die by applying a pressing force. As can be seen in Fig. 3, the pores IIa between the warp wires 9 and the weft wires 10 are of very small cross-section, in the present case, a porosity of the fabric of 5 - 25% is achieved. With the porosity of the fabric 7, the damping factor of the device 6 can be adjusted to a certain extent.

In Fig. 4 it can be seen that the weft wires 10 penetrate into the warp wires 9 by rolling, resulting in a deformation of the warp wires 9 and the weft wires 10 results. On the other hand, this also leads to a significantly increased friction of Warp wires 9 with the weft wires 10 and to an increased rigidity of the fabric. 7

FIG. 5 shows a second embodiment of the device 6 for absorbing structure-borne noise on the housing 1. Again, the fabric 7 is attached to the wall 5 of the housing 1 by means of an adhesion layer 8. In addition, on the side facing away from the housing 1 side of the fabric 7, a substantially smooth surface exhibiting plate 12 is attached, which contributes to a stiffening of the device 6 and to an improved absorption of structure-borne noise. The existing example of steel, stainless steel, aluminum, lead, plastic or ceramic sheet 12 is connected by means of a further adhesion layer 13 with the fabric 7 or mechanically connected to a sandwich with one of the outer walls 4, 5 of the housing 1.

In the illustrated in Fig. 6, the third embodiment of the device 6 is also connected to the adhesion layer 13 with the fabric 7 plate 12 is provided. In addition, on the side of the sheet 12 facing away from the fabric 7 there is another fabric 14, which is structured, e.g. is corrugated, and attached by means of a further adhesion layer 15 to the sheet 12 or mechanically joined.

Furthermore, as an alternative or in addition to the sheet 12, a plurality of other or additional material layers may be provided, wherein preferably the modulus of elasticity of the material layers increases, the farther the individual material layer is removed from the wall 4 or 5 of the housing 1. Preferably, the housing 1 is made of aluminum and the fabric 7 is made of steel. On the side facing away from the housing 1 of the fabric 7, a ceramic plate may be arranged to a corresponding -lo¬

chende, away from the housing 1 rising, E-module having arrangement to achieve.

Fig. 7 shows a further embodiment of the device 6, in which a plurality of layers of the fabric 7 are provided, which are interconnected by means of respective adhesion layers 8. As in the previously described embodiments, the fabric 5 closest to the wall 5 of the housing 1 is likewise attached to the housing 1 by means of the adhesion layer 8. By such a number of layers of the fabric 7, the above-described effect of the damping of the device 6 is improved. Depending on the available space can be provided in principle any number of layers of material. Thus, considerably more layers of the fabric 7 can be provided than shown in the figures.

In addition, in the embodiment of the device 6 shown in FIG. 7, the outermost, ie the furthest spaced from the housing 1 fabric 16 with a plurality, at least approximately perpendicular to the surface thereof directed studs 17 is provided. Instead of the knobs 17 waves can be provided. The fabric 16 is connected by means of a further adhesion layer 18 to the underlying fabric 7 or attached thereto. Here, as an alternative, the possibilities described above of mechanically joining the fabric 7 with the remaining fabrics 14 and / or 16 such as welding, screwing, riveting, etc. are also conceivable.

In one embodiment, not shown, one or more of the fabrics 7, 14 and / or 16 could also be perforated, perforated and / or profiled. The fabrics 7, 14 and / or 16 may be made of steel, stainless steel, aluminum, plastic, ceramic or a copper alloy, wherein the term plastic all non-naturally occurring materials should be included. In principle, the use of cotton, silk, linen or other natural fibers for the fabric 7, 14 and / or 16 is possible. In one embodiment, not shown, the warp wires 9 and / or the weft wires 10 may also have a plurality of individual wires in order to achieve a higher friction.

FIGS. 8 and 9 show a section through the fabric 7, in which only the weft wires 10 are shown. In particular, in Fig. 9 it can be seen that both of the weft wires 10 of the lower and the upper row of respective overpressure waves emanates, which picks up with the vacuum waves of the row of underlying weft wires 10, whereby an acoustic short circuit in the fabric 7 is formed. The positive and negative pressure waves caused by the oscillation of the wires 9 and 10, caused by the bending vibrations of the housing.

In Fig. 10, which shows the wall 5 of the housing 1 in a greatly enlarged scale with a correspondingly large increase in the vibrations of the wall 5, it can be seen that of the wall 5, a negative pressure wave and an overpressure wave emanates.

11 shows a further illustration to clarify the processes taking place in the tissue during the absorption of structure-borne noise. It can also be seen that between the individual weft wires 10 extending pressure waves compensate each other.

FIG. 12 shows a further embodiment of the device 6 for absorbing hydro-sound and structure-borne noise. Here, an oil pump 19 is provided, which is representative of hydraulically operating components and in which a liquid flow, in particular an oil stream is promoted. With the pump 19, an oil pan 20 is connected, in which there is a part of the funded by the pump 19 oil. In the present case, the pump 19 is connected by means of a line 21 to the oil pan.

Since the pressure fluctuations generated by pump wheels 22, the oil in the oil pan 20 is excited to vibrate, which can be transferred to the oil pan 20 or the housing of the pump 19, located within the oil pan 20, the device 6, which is the body. 1 a formed in the present case as a plate 23 structure on which the fabric 7 is attached.

The operation of the device 6 is the following: The pressure fluctuations prevailing in the oil cause the plate 23 to vibrate and in a similar or identical manner as described above by the friction taking place between the fabric 7 and the plate 23 and by dampens the internal friction of the fabric 7, so that there is a significant absorption of the otherwise radiated by the oil pan 20 and / or the pump 19 sound.

The device 6 can thus be used very advantageously also in liquid and air streams. All of the above-described embodiments of the device 6 can also be used in the embodiment of the device 6 shown in FIG. 12, unless obvious reasons contradict this.

FIG. 13 shows a further embodiment of the device 6. Here, a line 24 is provided, in which a sound-emitting source 25 is arranged. In the line 24, a gas stream, such. As an air stream, or it may also be just a container in which a Gas is housed. The line 24 is thus representative of pneumatically operating components.

In the conduit 24 there is a device 6 which, in a manner similar to the device 6 described with reference to Fig. 12, comprises the plate 23 and the tissue 7 attached to the plate 23. Again, there is an attenuation of the incident on the device 6 sound, so that a significant reduction in the emitted from the line 24 structure-borne sound is to be expected. Also in this embodiment, all the above-described developments of the device 6 are conceivable, if they are not excluded for obvious reasons.

Claims

Patent claims

1. A device for absorbing body, hydro and / or airborne sound, with a sound wave oscillating body (1,23) and with a fabric (7), which warp wires (9) and weft wires (10) and between the Knittdrähte (9) and the weft wires (10) formed pores (IIa) and at the contact points of the warp wires (9) with the weft wires (10) formed friction points (IIb), wherein the tissue (7) on the body (1, 23) is mounted so that when a sound of the body (1.23) friction between the tissue (7) and the body (1.23) takes place.

2. Device according to claim 1, characterized in that the tissue (7) by means of an adhesion layer (8) on the

Body (1.23) is attached.

3. A device according to claim 2, wherein: said adhesion layer (8) is an adhesive.

4. The device according to claim 2, characterized in that the adhesion layer (8) is a plastic film provided with an adhesive layer.

5. Device according to claim 2, 3 or 4, characterized in that the adhesion layer (8) is made of silicone.

6. Device according to claim 1, characterized in that the fabric (7) is attached to the body (1,23) by means of welding, screwing, riveting or pressing.

7. A device according to any one of claims 1 to 6, wherein a side facing away from the body (1,23) side of the fabric (7) has a smooth surface having sheet (12) is attached.

8. Device according to claim 7, characterized in that the sheet (12) having a smooth surface is attached to the fabric (7) by means of an adhesion layer (13).

9. The device according to claim 1, wherein a plurality of layers of the fabric are provided.

10. Device according to claim 9, characterized in that the individual layers of the fabric (7, 14) are replaced by respective ones

Adhesion layers (15) are interconnected.

11. The device according to claim 1, wherein the modulus of increase of the material layers increases, the farther the material layer is removed from the wall (4, 5) of the housing (1).

12. Device according to claim 11, characterized in that the body (1, 23) is made of aluminum and the fabric (7, 14, 16) is made of

Steel exists.

13. Device according to claim 11 or 12, characterized in that a plate made of ceramic is arranged on the side of the fabric (7) facing away from the body (1, 23).

14. Device according to one of claims 1 to 12, characterized in that the fabric (7, 14, 16) is rolled.

15. The device according to claim 1, wherein the porosity of the fabric (7, 14, 16) is about 5 to 25%, according to one of claims 1 to 14, characterized in that the porosity of the fabric (7, 14, 16) is.

16. The device according to claim 1, wherein the fabric is provided with knobs directed at least approximately perpendicular to the surface of the fabric.

17. Device according to one of claims 1 to 16, characterized in that the fabric (7, 14, 16) is corrugated.

18. Device according to one of claims 1 to 17, a d u c h e c e n e c e s that the fabric (7, 14, 16) consists of steel, stainless steel, aluminum, plastic, ceramic, a copper alloy or a natural fiber.

19. Device according to one of claims 1 to 18, characterized in that the body (1,23) is formed as a housing (1), in particular as a housing (1) in which a shaft (2) is rotatably mounted.

20. Device according to one of claims 1 to 18, a d u c h e c e n e c e s in that the body (1, 23) is designed as a structure arranged in a liquid or in a gas stream, in particular as a plate (23).

21. The device according to claim 1, wherein the warp wires and / or the weft wires have a plurality of individual wires.