DE102015100020A1 - Arrangement for reducing sound - Google Patents

Abstract

The invention relates to an arrangement for reducing the sound caused by a sound source (6) with respect to sound acting in an outdoor area to the sound source (6) by means of a counter sound generated by a counter sound source (4, 5), the sound source (6) having walls has, let the sound through or radiate. In order to achieve an effective reduction of sound by counter-sound in the outer region of an object, which object itself is a sound source or has in its interior a sound source, which deliver sound via walls of the object to the outside, it is proposed that a plurality of channel sections are provided associated with one of these channel sections a plurality of counter-sound sources (4, 5) are arranged, which are adjustable so that the sound waves of these counter-sound sources (4, 5) to the sound source (6) out by superimposing essentially extinguish.

Description

The invention relates to an arrangement for reducing the sound caused by a sound source with respect to acting in an outdoor area to the sound source sound, generated by means of a counter-sound source counter sound, wherein the sound source has walls that transmit or emit sound.

The suppression of sound by counter-sound is already widely known. It is for example on the WO 2013/160113 A2 directed.

However, when sound is generated from a sound source and the sound source is arranged in a room, the generation of back noise for suppressing the sound outside the sound source often involves a problem that the back sound itself enters the room or has an essential directed into the room component and in the interior of the room through the walls and thus possibly triggered reflections even an amplification of sound may occur. It is then rather not to a weakening of the ultimately measurable outdoor sound.

Proceeding from this, the invention is concerned with the task of achieving an effective reduction of sound by counter-sound in the outer region of an object, which object itself is a sound source or has in its interior a sound source, which emit sound via walls of the object to the outside.

This object is achieved initially and essentially in an arrangement in which a plurality of channel sections are provided, wherein associated with one of these channel sections a plurality of counter-sound sources are arranged so that the sound waves of these counter-sound sources to the sound source out by overlay anyway in the Essentially extinguish.

It can also come to an intrusion of the counter-noise into the interior of the sound source and then a further extinction of the, if applicable, generated in the interior of the sound source sound can be achieved.

With regard to the sound source may be very different designs. In particular, a space bounded by outer walls. It may be in this respect a room with wood or metal or concrete walls or walls made of other material, possibly also of plastic. The passage area for the sound from an interior to the outside or with respect to the counter sound also from outside to inside, can be given by a wall itself. It can also be given in the form of a free opening, for example corresponding to a window opening. There does not have to be an actual window. There may also be an unoccupied passage opening. But it can also be given a window or a membrane, so that no direct exchange of air or other media exchange is made possible by such a passage area. The plurality of channel sections may be associated with one passage area or one passage area each. However, they can also be associated with a wall which is otherwise continuous.

With regard to a medium in the room in which optionally only the actual sound source is arranged, it may initially and above all be air, such as in a conventional living room, utility room or the like. But it may also be a medium, such as a fluid, which is liquid, such as water. It may also be a special gas such as nitrogen, a noble gas such as argon, helium, neon or the like.

Due to the fact that in any case two counter-sound sources are always assigned to one of the channel sections, they can be arranged in the direction of enforcement of the channel section, for example, one behind the other or next to one another. In a manner known per se, they can be matched to one another in terms of sound generation so that one of the counter-sound sources is designed to extinguish the sound radiated by the sound source - in the interior of the room - or the sound further emitted thereby by a wall. However, the further sound source can then be turned off from the actual counter-sound, which in terms of frequency and timing can be somewhat different from the sound from the sound source in the interior of the room. Thus, the sound radiated from the further counter-sound source is capable of eliminating it in exact adaptation to the sound radiated from the first counter-sound source with respect to its sound ultimately radiated into the interior of the room.

Reflections or even multiple reflections of the counter-sound with respect to the wall, the sound radiates or with respect to the room in which the actual sound source is effectively prevented by interconnecting several counter-sound sources to a quasi-then then acting counter-sound source (per channel section). A directional characteristic of the thus resulting, interconnected from two or more individual counter-sound sources total counter-sound source is adjustable. It can be adjusted so that the sound waves, the otherwise repeated disturbing reflections, especially in the mentioned space, are attenuated in the appropriate direction so strong that results in a loop gain of less than 1 and thus can not be coupled.

By such an arrangement of counter-sound sources, the reflection factor at the point of superimposition of sound and counter sound is brought close to zero, so that hardly more reflections and the reflected by the antinoise sources sound sources no longer the control behavior of the - actually tuned to the sound source - counter-sound source can disturb.

In a preferred embodiment, it is based on that the different channel sections associated counter-sound sources are uncrosslinked with each other. They are therefore not coordinated or tunable. Rather, the counter-sound sources assigned to a channel section preferably operate independently.

It is also preferred that the channel section is oriented so that one end points to an interior of the sound source and the other to its outside. In particular, a longitudinal axis of a channel portion may be aligned perpendicularly with respect to an outer surface or a portion of the outer surface to which the channel portion is assigned. The end facing the interior may be seated directly on the outer surface or spaced therefrom.

It is also preferred that a channel section has a constant diameter over its length. Furthermore, a channel section may be designed in dependence on the sound to be damped, which is caused by the sound source, such that substantially only one plane wave is set in the channel.

In any case, one or more of the antinoise sources may also be arranged in the channel itself. Two or more of the several counter-sound sources can be combined into one module.

It is also preferred that a plurality of channel sections are provided, which plurality are assigned in total to said sound source or said object. Each individual channel section of this plurality may be aligned or arranged as described above and below with respect to a channel section.

In particular, the channel sections assigned to a wall or a wall section of the article can be arranged rectified.

It is also preferable for the counter-sound sources assigned to a channel section to be assigned a microphone which is used to determine the counter-sound to be generated.

In any case, with regard to two counter-sound sources assigned to one channel section, the microphone can be arranged on the side of these counter-sound sources assigned to the outside area

Advantageously, the two or more counter-sound sources, which are assigned to a same channel section in the direction of propagation of the sound in the channel section one behind the other, further advantageous such that the counter sound source on the sound from the sound source, optionally in the room, outside matched with respect to the other counter-sound source, which Suppression of the radiated from the first sound source antinoise task is arranged.

With regard to the dimensions of a channel section as such, the characteristic of the sound produced by the sound source, possibly the sound source inside the object, is important. The channel section is in terms of its (largest) width, which may be provided in a particular case, a cylindrical channel section, which it is evident then only arrives at the diameter, dimensioned depending on the wavelength. Thus, a largest dimension transverse to the propagation direction of the sound wave in the channel section or transversely to a longitudinal extension of the channel section may preferably correspond to approximately half the wavelength. For example, a bandwidth of 0.3 times to 0.7 times the wavelength may still provide sufficient results. In further detail, in the case of a rectangular channel section, the largest transverse dimension may be equal to or less than half the speed of sound in the respective medium divided by the frequency. Downwards, this largest dimension is u. a. also limited by the fact that in any case one of the counter-noise sources should be arranged in the channel section and this counter-sound source has a corresponding physical size. Thus, a realistic lower limit of about 2 to 4 cm for this largest dimension can be selected transversely to the direction of extension of the sound or to the passage direction of the channel section. The smallest dimension, with a rectangular channel cross-section the dimension of a narrow side, can amount to 10 to 99 percent of the largest dimension.

A channel wall is preferably made of a reverberant material. It may be - starting from wood or plastic - also for example, metal. In further detail, the material may be MDF For example, plates, sheet steel or KS-Stein. Such a channel section is also preferably formed closed with respect to its entire length with respect to the wall.

The length of a channel section preferably corresponds to the largest dimension in the width direction or a multiple thereof, wherein a non-integer multiple is also included here. Approximately up to 5 or 10 times the mentioned largest width dimension.

With regard to the longitudinal extent of the channel section is to ensure a sufficient length. In absolute terms, lengths of 30 cm or more, up to, for example, 60 or 80 cm, with a preferred length in the range of 50 cm, are preferred. In this way, sound waves passing therethrough up to an upper limit frequency whose half wavelength corresponds to the largest transverse dimension of the single volume formed by such a channel section can be attenuated locally in this single volume (channel section) by a single counter-sounding source.

In further detail, it is also preferred that two or more counter-sound sources, which are each assigned to a channel section (if a plurality of channel sections are provided), are combined to form a module. This means that the counter-sound sources can be arranged in a common housing or a common support structure. You can thereby be handled together.

Such a module also has independent significance in the context of the application.

The module may contain "intelligence" in further detail, which is required to control the antinoise sources. This can be a processor with a suitable algorithm, which then calculates in each case depending on the sound signals received by a microphone, the respective counter sound and controls the generation of this antinoise by a counter sound source.

Furthermore, one or more microphones are preferably assigned to each of these multiple counter-sound sources assigned to one channel section. The microphones or the microphones are further preferably at least arranged with respect to two counter-sound sources assigned to one channel section on the side of these counter-sound sources assigned to the outside area. The microphone is preferably also accommodated in the module.

With regard to the object under consideration, as already mentioned, a plurality of channel sections can be provided. For example, as far as provided, a plurality of such channel sections can also be assigned to a single passage area. For example, two or more channel sections, up to 20, 30 or more, may be provided, which may be combined to one or more through openings assigned.

It is essential that a self-sufficient, self-sufficient antinoise system is provided in each channel section. The counter-sound sources assigned to one channel section operate independently of the further channel sections or otherwise provided counter-sound sources.

In each case, a local attenuation of the given in the channel section or adjusting even sound pressure wave is achieved. The individual muting systems acting independently of one another thus provide an effective reduction of the total sound emitted by the sound source. Any influence on the antinoise sources of neighboring systems, d. H. However, this adjacent channel sections on the respective microphones can practically not affect the stability of the damping effect. Optionally, a dynamic limitation of the sensor inputs may be provided, so that a still occurring, smaller disturbance in the case of attenuation may affect the subsequent signal processing even less. The individual counter sound systems preferably use the known feed forward strategy, in which a signal for driving a counter sound source is obtained from a reference signal, which does not originate from a control microphone. Thereby, a further improvement of the stability can be achieved. Further stabilization can also be achieved by using a so-called leaky LMS algorithm. However, an achievable attenuation can be reduced thereby.

An exemplary application of this arrangement relates to a transformer housing. An electrical transformer may be comprised of a separate housing, a transformer housing. Accordingly, this transformer housing encloses a room inside, in which then the transformer is located as a sound source. In particular, the transformer housing can have rib structures on the outside, in particular ribs which extend vertically in the installation state. A space between two such ribs can already form a boundary of a channel section, in which case a boundary is additionally drawn in vertically upwards and downwards by a further wall. Preferably, however, one or more complete channels are arranged between such rib structures as described.

In the following, the invention will be explained further with reference to the attached drawing, which, however, represents only exemplary embodiments. Hereby shows:

1 a schematic external view of a transformer;

2 a schematic drawing of a wall portion of the transformer with antinoise sources;

3 a representation according to 2 with inserted channel section; and

4 a representation of a module with antinoise sources.

Shown and described is first with reference to 1 a standard transformer 1 , The transformer 1 has a transformer housing with an outer wall 3 and outside ribs 2 on, which are known to be advantageous primarily for heat dissipation.

Such a transformer 1 can be set up outdoors. But it can also be placed in a transformer room.

Such a transformer 1 causes noise in normal operation, which over the ribs 2 and the outer wall 3 generally leak into the environment.

As can be seen from the schematic representation according to 2 results, it is now provided that the outside of the transformer 1 , preferably between two more preferably in the vertical direction extending ribs 2 several counter-sound sources 4 . 5 are arranged to this as a reduced sound source 6 characterized by emitting sound across the wall of the transformer.

The counter-sound sources 4 . 5 are, as is clear from the further concretization according to 3 results in a channel section 7 arranged. And more preferably within a module 8th which is in the canal section 7 is arranged. But you can also directly in the channel section 7 be attached immediately.

In addition, which is not shown in detail, is the outer surface of the transformer 1 with a variety of such counter-sound sources 4 . 5 or preferably channel sections 7 with further preferred arranged therein modules 8th Mistake.

The area may be covered by 10 to 90 percent or more of such counter sound source arrangements, including microphone, or corresponding channel sections.

The variety of different channel sections 7 are with regard to the counter sound sources 4 . 5 preferably not crosslinked with each other. Rather, the counter sound sources are preferred 4 . 5 a channel section 7 just matched.

A channel section 7 more preferably has an inlet cross-section 9 and an outlet cross section 10 on. The channel section 7 is as regards the inlet and outlet cross-sections 9 . 10 open channel section preferably formed. In addition, the arrangement of a channel section 7 apparently chosen so that the inlet cross section 9 the wall of the object to be damped, here the transformer 1 is assigned, the outlet cross-section 10 but facing out into the open.

A channel section 7 can over its length l a constant diameter, namely in particular free diameter.

It is the two counter-sound sources that are preferred (only) in one channel section 7 are provided, in the direction of the length l of the channel section 7 preferably arranged one behind the other. There may also be several counter sound sources 4 . 5 in a canal section 7 be arranged.

Next is in a channel section 7 , specifically and preferably also in a related module 8th , please refer 4 , next to the counter-noise sources 4 . 5 also a microphone 11 intended. In addition, a sound generator 12 be provided in the module. In addition, an electronic control is provided here by a microchip 13 is marked or symbolized.

All said aggregates may preferably be in said module 8th be provided summarized. You can also each individually in a channel section 7 be installed.

Such a channel section may have a rectangular free cross-section. It can have a width b and a height h. It can also have a round inner free cross section. For a rectangular free cross-section, the ratio of b to h can be 1.1 to 4 or more.

The further design of a channel section 7 With respect to its free inner cross section and thus free interior is preferably provided so that, depending on the sound to be attenuated substantially in the channel section 7 only sets a plane wave in terms of sound.

The above explanations serve to explain the inventions as a whole covered by the application, which independently further develop the state of the art, at least by the following combinations of features, namely:
An arrangement characterized in that a plurality of channel sections 7 are provided that assigned to one of these channel sections 7 several counter-sound sources 4 . 5 are arranged, which are adjustable so that the sound waves of these counter-sound sources 4 . 5 to the sound source 6 In any case, they are essentially canceled out by superposition.

An arrangement characterized in that the different channel sections 7 associated counter-noise sources 4 . 5 are uncrosslinked with each other.

An arrangement characterized in that the channel section 7 Aligned so that an end to an interior of the sound source 6 and the other to the outside area.

An arrangement characterized in that a channel section 7 has a constant diameter over its length.

An arrangement characterized in that a channel section 7 depending on the sound source to be damped 6 caused sound is formed so that essentially only a plane wave in the channel section 7 established.

An arrangement which is characterized in that in any case one of the several counter-sound sources 4 . 5 is arranged in the channel.

An arrangement characterized in that two or more of the plurality of counter sound sources 4 . 5 to a module 8th are summarized.

An arrangement characterized in that a plurality of channel sections 7 are provided.

An arrangement characterized in that the channel sections associated with a wall or a wall section 7 are arranged rectified.

An arrangement characterized in that the one channel section 7 associated counter-noise sources 4 . 5 a microphone for determining the counter sound to be generated 11 assigned.

An arrangement characterized in that the microphone 11 at least with respect to two of a channel section 7 associated counter-noise sources 4 . 5 on the outside of this associated counter-sound sources 4 . 5 is arranged.

LIST OF REFERENCE NUMBERS

1

transformer

2

ribs

3

outer wall

4

Against sound source

5

Against sound source

6

sound source

7

channel section

8th

module

9

Inlet cross-section

10

Outlet cross section

11

microphone

12

sound generator

13

microchip

b

 width

H

 height

l

 length

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2013/160113 A2 [0002]

Claims (12)

Arrangement for reducing the sound source ( 6 ) caused sound in relation to in an outdoor area to the sound source ( 6 ) acting sound, by means of a counter sound source ( 4 . 5 ) generated counter sound, wherein the sound source ( 6 ) Has walls that transmit or radiate sound, characterized in that a plurality of channel sections ( 7 ) that are assigned to one of these channel sections ( 7 ) several counter-sound sources ( 4 . 5 ) are arranged, which are adjustable so that the sound waves of these antinoise sources ( 4 . 5 ) to the sound source ( 6 In any case, they are essentially canceled out by superposition. Arrangement according to claim 1, characterized in that the different channel sections ( 7 ) associated counter-sound sources ( 4 . 5 ) are uncrosslinked with each other. Arrangement according to claim 1 or 2, characterized in that the channel section ( 7 ) is aligned so that an end to an interior of the sound source ( 6 ) and the other to the outside area. Arrangement according to one of the preceding claims, characterized in that a channel section ( 7 ) has a constant diameter over its length. Arrangement according to one of the preceding claims, characterized in that a channel section ( 7 ) depending on the sound source to be damped ( 6 ) is formed so that essentially only a plane wave in the channel section ( 7 ). Arrangement according to one of the preceding claims, characterized in that in any case one of the several counter-sound sources ( 4 . 5 ) is disposed in the channel. Arrangement according to one of the preceding claims, characterized in that two or more of the several counter-sound sources ( 4 . 5 ) to a module ( 8th ) are summarized. Arrangement according to one of the preceding claims, characterized in that a plurality of channel sections ( 7 ) are provided. Arrangement according to one of the preceding claims, characterized in that the wall sections or a wall portion associated with ( 7 ) are arranged rectified. Arrangement according to one of the preceding claims, characterized in that the one channel section ( 7 ) associated counter-sound sources ( 4 . 5 ) a microphone for determining the counter sound to be generated ( 11 ) assigned. Arrangement according to one of the preceding claims, characterized in that the microphone ( 11 ) in any case with respect to two of the one channel section ( 7 ) associated counter-sound sources ( 4 . 5 ) on the outside of this associated counter-sound sources ( 4 . 5 ) is arranged. Arrangement, characterized by one or more of the characterizing features of one of the preceding claims.

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