Square type local resonance broadband sound absorption panel, design method and noise reduction shell

Abstract

The invention discloses a square local resonance broadband sound absorption panel, a design method and a noise reduction shell, and relates to the technical field of noise reduction structures. According to the design method, a sound absorption panel comprises a plurality of sound absorption units, each sound absorption unit is of a frame structure provided with a plurality of square resonant cavities arranged in an array mode and a plurality of throat pipes, and the throat pipes are installed on the end walls of the first ends of the square resonant cavities and communicate with the external environment of the sound absorption units and the corresponding square resonant cavities; the design method comprises the following steps: S1, acquiring sound wave angular frequency, sound velocity and acoustic impedance, and acquiring two of the pipeline sectional area of the throat pipe, the volume of the square resonant cavity and the equivalent length of the throat pipe; s2, according to the parameters obtained in the step S1, the remaining one of the pipeline sectional area of the throat pipe, the volume of the square resonant cavity and the equivalent length of the throat pipe is obtained; the square-format local resonance broadband sound absorption panel manufactured by adopting the design method can absorb low and medium frequency noise.

Description

Technical Field

[0001] The present invention relates to the technical field of noise reduction structures, and more specifically, to a design method for a grid-shaped, locally resonant, broadband sound-absorbing panel. Furthermore, the present invention relates to a grid-shaped, locally resonant, broadband sound-absorbing panel manufactured using the aforementioned design method. Furthermore, the present invention relates to a noise reduction housing incorporating the aforementioned grid-shaped, locally resonant, broadband sound-absorbing panel. Background Art

[0002] Noise pollution seriously affects all aspects of people's work, life, and transportation. For example, the noise in people's environment seriously affects their rest and sleep quality, as well as their work efficiency. The noise generated by the operation of transportation equipment such as rail vehicles and airplanes may cause auditory fatigue to passengers, making it difficult for them to hear conversations for a short period of time after getting off the vehicle. Noise can even cause people to suffer from physical or psychological diseases. Reducing equipment noise has gradually become an important part of product design and development.

[0003] Traditional sound-absorbing structures are generally based on porous materials. The main function of this type of material is to absorb medium and high-frequency noise, but it is difficult to reduce the medium and low-frequency noise of the product.

[0004] In summary, how to reduce the mid- and low-frequency noise of a product is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a square local resonance broadband sound absorption panel. Through this design method, a square local resonance broadband sound absorption panel capable of absorbing medium and low frequency noise can be manufactured.

[0006] Another object of the present invention is to provide a square local resonance broadband sound absorbing panel manufactured using the above-mentioned design method of the square local resonance broadband sound absorbing panel.

[0007] Another object of the present invention is to provide a noise reduction shell comprising the above-mentioned square-shaped local resonance broadband sound absorption panel.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A design method for a square-shaped local resonance broadband sound absorption panel, the square-shaped local resonance broadband sound absorption panel comprising a plurality of sound absorption units, each of which is a frame structure having a plurality of square resonance cavities arranged in an array and a plurality of throats, the throats being mounted on end walls at first ends of the square resonance cavities and connecting the external environment of the sound absorption unit with the corresponding square resonance cavities;

[0010] The design method includes:

[0011] S1: Get the angular frequency of the sound wave , speed of sound , acoustic impedance , and obtain the pipe cross-sectional area of ​​the throat , the volume of the square resonant cavity Equivalent length of throat Both of them;

[0012] S2: According to the sound wave angular frequency , the speed of sound , the acoustic impedance and the pipe cross-sectional area of ​​the throat , the volume of the square resonant cavity and the equivalent length of the throat To obtain the pipe cross-sectional area of ​​the throat , the volume of the square resonant cavity and the equivalent length of the throat The remaining one in .

[0013] Preferably, the S2 includes:

[0014] according to , get the pipe cross-sectional area of ​​the throat , the volume of the square resonant cavity and the equivalent length of the throat The remaining one of

[0015] Where: is the target acoustic impedance; j is the imaginary unit; is the angular frequency of the sound wave of the noise in the target frequency band; is the speed of sound when noise propagates in air;

[0016] is the equivalent length of the throat, and , L is the length of the throat pipe section inserted into the square resonance cavity, is the path length of the noise propagating into the pipe section of the throat located in the square resonance cavity, and r is the pipe radius of the throat; is the cross-sectional area of ​​the throat, and ;

[0017] is the volume of the square resonant cavity, , H is the depth of the square resonance cavity; b is the side length of the square resonance cavity.

[0018] Preferably, the S2 includes:

[0019] S21: Set the pipe radius r of the throat according to requirements, and set the volume of the square resonance cavity according to requirements , and then according to the Determine the equivalent length of the throat ;

[0020] Or, S211: Set the pipe radius r of the throat according to the requirements, and set the equivalent length of the throat according to the requirements , and then according to the Determine the volume of the square resonant cavity .

[0021] Preferably, the S21 and S211 include:

[0022] The pipe radius r of some of the throats is greater than or equal to 0.5 mm.

[0023] Preferably, the S21 includes:

[0024] The sizes of the plurality of square resonance cavities are the same.

[0025] Preferably, the S21 and S211 include:

[0026] S2111: According to , get the cross-sectional area of ​​the throat pipe , the volume of the square resonant cavity Equivalent length of throat The remaining one in .

[0027] A square local resonance broadband sound absorbing panel is manufactured using any of the above-mentioned design methods for a square local resonance broadband sound absorbing panel, comprising a plurality of sound absorbing units;

[0028] The sound absorbing unit includes a sound absorbing plate, a plurality of throats, and a sound absorbing body having a plurality of square resonance cavities arranged in an array;

[0029] The sound absorbing plate is covered on one end of the sound absorbing body to close the corresponding end opening of the square resonance cavity;

[0030] The sound absorbing plate body has a sound absorbing hole, the sound absorbing hole is connected to the corresponding square resonance cavity, the throat is installed on the sound absorbing plate body, and the throat is connected to the corresponding square resonance cavity and the external environment of the sound absorbing unit through the corresponding sound absorbing hole, and the inner diameter of the sound absorbing hole is equal to the pipe radius of the corresponding throat;

[0031] The dimensions of the interconnected sound absorbing holes, the throat and the square resonance cavity meet the requirements. .

[0032] Preferably, the wall thickness of the structure between adjacent square resonance cavities in the sound absorbing body is 0.5 mm, the length of the throat extending into the square resonance cavity is 37.5 mm, the side length of the square resonance cavity is 9 mm, and the depth of the square resonance cavity is 49.5 mm. The sound absorbing plate body is a flat plate, and the thickness of the sound absorbing plate body is 0.5 mm.

[0033] The number of the square resonant cavities is 25, and some of the square resonant cavities are The square resonance cavities are arranged in an array, and the square resonance cavities in the first row, the second row, the third row, the fourth row, and the fifth row are arranged in sequence along the width direction of the sound absorbing body, and several of the square resonance cavities in each row are arranged along the length direction of the sound absorbing body;

[0034] In the square resonant cavity of the first column, the radius r of the pipe corresponding to the throat pipe is 0.47 mm, 0.48 mm, 0.49 mm, 0.53 mm, and 0.535 mm respectively;

[0035] In the square resonant cavity of the second column, the radius r of the pipe corresponding to the throat pipe is 0.545 mm, 0.555 mm, 0.585 mm, 0.625 mm, and 0.675 mm respectively;

[0036] In the square resonant cavity of the third column, the radius r of the pipe corresponding to the throat pipe is 0.725 mm, 0.78 mm, 0.84 mm, 0.9 mm, and 0.95 mm respectively;

[0037] In the square resonant cavity of the fourth column, the radius r of the pipe corresponding to the throat pipe is 0.99 mm, 1.08 mm, 1.15 mm, 1.21 mm, and 1.25 mm respectively;

[0038] In the square resonance cavity of the fifth column, the radius r of the pipe corresponding to the throat is 1.35 mm, 1.52 mm, 1.67 mm, 1.86 mm, and 1.9 mm respectively.

[0039] Preferably, the corners of the square resonant cavities are rounded, and in two adjacent rows of the square resonant cavities, the rounded corners of the square resonant cavities in one row are located in the middle of the side surfaces of the corresponding square resonant cavities in the other row.

[0040] Preferably, the sound absorbing unit is an aramid frame structure formed by roller rubber stretching.

[0041] A noise reduction shell comprises a shell body and the square local resonance broadband sound absorption panel described in any one of the above items, wherein the square local resonance broadband sound absorption panel is arranged on the reflection surface of the shell body on the side of the sound source.

[0042] The present invention provides a design method for a square-shaped local resonance broadband sound-absorbing panel. The designed sound-absorbing unit has a hollow structure, and the interior of the sound-absorbing unit has a barrier structure, so that the inner cavity of the sound-absorbing unit is divided into a plurality of independent square resonance cavities, and the plurality of square resonance cavities are arranged in an array. Furthermore, the first end of the sound-absorbing unit has an end wall to close the corresponding end openings of the plurality of square resonance cavities, and a through-hole is provided in the middle position of the end wall of the first end of the sound-absorbing unit to insert a throat or conduct the inner cavity connected to the throat. That is, the throat is supported and installed in the sound-absorbing unit through the end wall of the first end, and noise in the external environment of the sound-absorbing unit can be transmitted into the corresponding square resonance cavity through the throat, so as to absorb the noise through the resonance principle. Furthermore, in step S1, the angular frequency of the sound wave is first determined according to the frequency band of noise absorption required by the product design. , determine the acoustic impedance based on the sound absorption coefficient given by the product design requirements , and determine the speed of sound that noise propagates in air , and then preset the pipe cross-sectional area of ​​the throat , the volume of the square resonant cavity Equivalent length of throat To obtain the cross-sectional area of ​​the throat pipe , the volume of the square resonant cavity Equivalent length of throat The remaining one of them can be used to manufacture a square-shaped local resonance broadband sound-absorbing panel with the required size.

[0043] The design method of the square local resonant broadband sound-absorbing panel provided in this application can manufacture a square local resonant broadband sound-absorbing panel that can absorb medium and low frequency noise, and the square local resonant broadband sound-absorbing panel manufactured by this design method has a small volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0045] Figure 1 This is a flow chart of the design method of the grid-type local resonance broadband sound-absorbing panel provided by the present invention;

[0046] Figure 2 This is a schematic structural diagram of the sound absorbing unit of the first specific embodiment of the square local resonance broadband sound absorbing panel provided by the present invention;

[0047] Figure 3 This is a schematic structural diagram from another angle of the sound absorbing unit of the specific embodiment 1 of the square local resonance broadband sound absorbing panel provided by the present invention;

[0048] Figure 4 This is a frequency-sound absorption coefficient curve of the specific embodiment 1 of the square local resonance broadband sound absorption panel provided by the present invention;

[0049] Figure 5 This is a schematic structural diagram of the sound absorbing unit of the second specific embodiment of the square local resonance broadband sound absorbing panel provided by the present invention;

[0050] Figure 6 This is a frequency-sound absorption coefficient curve of the specific embodiment 2 of the square local resonance broadband sound absorption panel provided by the present invention;

[0051] Figure 7 A schematic diagram of a specific embodiment of a square local resonance broadband sound absorbing panel provided by the present invention;

[0052] Figure 8 Another schematic diagram of a specific embodiment of the square local resonance broadband sound absorbing panel provided by the present invention;

[0053] Figure 9 This is another schematic diagram of a specific embodiment of the square local resonance broadband sound absorbing panel provided by the present invention.

[0054] Reference numerals:

[0055] 1-sound absorbing unit; 11-sound absorbing plate; 12-throat; 13-sound absorbing body; 131-square resonance cavity. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0057] The core of this invention is a design method for a grid-shaped local resonant broadband sound-absorbing panel. This design method enables the production of a grid-shaped local resonant broadband sound-absorbing panel capable of absorbing mid- and low-frequency noise. Another core of this invention is a grid-shaped local resonant broadband sound-absorbing panel manufactured using the aforementioned design method. Yet another core of this invention is a noise-reducing enclosure comprising the aforementioned grid-shaped local resonant broadband sound-absorbing panel.

[0058] Please refer to Figure 1The present invention provides a design method for a square local resonance broadband sound absorption panel. The square local resonance broadband sound absorption panel includes a plurality of sound absorption units 1. The sound absorption unit 1 is a frame structure having a plurality of square resonance cavities 131 arranged in an array and a plurality of throats 12. The throats 12 are installed on the end wall of the first end of the square resonance cavity 131 and connect the external environment of the sound absorption unit 1 with the corresponding square resonance cavity 131.

[0059] Specifically, such as Figure 3 As shown, the pre-designed sound absorbing unit 1 is a hollow structure, and the interior of the hollow structure has a barrier structure, so that the inner cavity of the hollow structure is divided into a plurality of independent square resonance cavities 131, and the plurality of square resonance cavities 131 can be formed in the form of or or Other types of array arrangements; furthermore, Figure 2 As shown, the right end of the sound absorbing unit 1 has a blocking structure to close the right end openings of the plurality of square resonance cavities 131. A through-hole is provided in the middle of the blocking structure to insert the throat 12 or to connect the inner cavity of the throat 12. That is, the throat 12 is supported and mounted by the blocking structure, and noise in the external environment of the sound absorbing unit 1 can be transmitted into the square resonance cavity 131 through the throat 12, thereby absorbing the noise through the principle of resonance.

[0060] The design method includes the following steps:

[0061] Step S1: Obtain the sound wave angular frequency , speed of sound , acoustic impedance , and obtain the pipe cross-sectional area of ​​the throat 12 、Square resonant cavity 131 volume Equivalent length to throat 12 In step S1, the angular frequency of the sound wave is determined according to the frequency band of the noise absorbed by the product design requirements. , determine the acoustic impedance based on the sound absorption coefficient given by the product design requirements , and determine the speed of sound that noise propagates in air .

[0062] Step S2: According to the angular frequency of the sound wave , speed of sound , acoustic impedance and the cross-sectional area of ​​the throat 12 、Square resonant cavity 131 volume Equivalent length to throat 12 To obtain the pipe cross-sectional area of ​​the throat 12 、Square resonant cavity 131 volume Equivalent length to throat 12 In step S2, according to the pipe cross-sectional area of ​​the throat obtained in the previous step , the volume of the square resonant cavity Equivalent length of throat To obtain the cross-sectional area of ​​the throat pipe , the volume of the square resonant cavity Equivalent length of throat The remaining one of them can be used to manufacture a square-shaped local resonance broadband sound-absorbing panel with the required size.

[0063] The design method of the square local resonant broadband sound-absorbing panel provided in this application can manufacture a square local resonant broadband sound-absorbing panel that can absorb medium and low frequency noise, and the square local resonant broadband sound-absorbing panel manufactured by this design method has a small volume.

[0064] Based on the above embodiment, step S2 includes: , get the pipe cross-sectional area of ​​the throat 12 、Square resonant cavity 131 volume Equivalent length to throat 12 The remaining one of

[0065] Where: is the target acoustic impedance; j is the imaginary unit; is the angular frequency of the sound wave of the noise in the target frequency band; is the speed of sound when noise propagates in air;

[0066] is the equivalent length of the throat 12, and , L is the length of the throat pipe 12 inserted into the square resonance cavity 131, is the path length of the noise propagating into the throat pipe 12 located in the square resonance cavity 131, and r is the pipe radius of the throat pipe 12; is the pipe cross-sectional area of ​​the throat 12, and ;

[0067] is the volume of the square resonant cavity 131, , H is the depth of the square resonance cavity 131 ; b is the side length of the square resonance cavity 131 .

[0068] Combined with the data obtained in step S1, the cross-sectional area of ​​the throat pipe 12 can be determined. 、Square resonant cavity 131 volume Equivalent length to throat 12 All three meet the Square local resonance broadband sound absorbing panel.

[0069] For example, in some specific embodiments, step S2 includes S21111: setting the volume of the square resonant cavity 131 as needed. , Equivalent length of throat 12 , you can pass The pipe radius r of the throat pipe 12 is determined.

[0070] It should be noted that L refers to the length of the pipe section of the throat pipe 12 extending in the square resonance cavity 131. is the path length of the section of the throat pipe 12 located in the square resonance cavity 131 for noise propagation. For example, in some specific embodiments, the structure of the sound absorbing unit 1 is as follows: a sealed cover at one end of the square resonance cavity 131 is provided with a sound absorbing plate 11, and one end of the throat pipe 12 is inserted into a corresponding sound absorbing hole opened on the sound absorbing plate 11, and the other end extends into the corresponding square resonance cavity 131. is the thickness of the sound absorbing plate 11; or, in other specific embodiments, the structure of the sound absorbing unit 1 is as follows: a sealed cover at one end of the square resonance cavity 131 is provided with the sound absorbing plate 11, and one end of the throat 12 abuts the sound absorbing plate 11, and the other end extends in the corresponding square resonance cavity 131, and the center line of the inner hole of the throat 12 is collinear with the center line of the corresponding sound absorbing hole on the sound absorbing plate 11, and the pipe radius r of the throat 12 is equal to the radius of the corresponding sound absorbing hole, then That is the length of the sound-absorbing hole.

[0071] For example, in some specific embodiments, Figure 5 As shown, in a sound absorbing unit 1, the depth of the square resonance cavity 131 is 198.5 mm, the cross-sectional width and length of the square resonance cavity 131 are both 11 mm, the wall thickness between adjacent square resonance cavities 131 is 1.5 mm, the wall thickness of the outermost wall of several square resonance cavities 131 is 0.75 mm, the thickness of the flat sound absorbing plate 11 is also 1.5 mm, the length of the throat 12 extending into the square resonance cavity 131 is 16.5 mm, and in some specific In the embodiment, the total length of the throat pipe 12 is 18 mm, and a 1.5 mm long section of the throat pipe 12 at one end is inserted on the sound-absorbing plate body 11. In other specific embodiments, the total length of the throat pipe 12 is 16.5 mm, and one end of the throat pipe 12 is located in the corresponding square resonance cavity 131, and the other end abuts and is sealedly connected to the sound-absorbing plate body 11. The centerline of the inner hole of the throat pipe 12 is collinear with the centerline of the corresponding sound-absorbing hole, and the pipe radius r of the throat pipe 12 is equal to the radius of the corresponding sound-absorbing hole.

[0072] Matching, such as Figure 2 As shown, the wall thickness of the plurality of throat pipes 12 is 1 mm, and the pipe radius r of the four throat pipes 12 in the first row from left to right, from top to bottom, is ; ; ; ; Among the four throat pipes 12 in the second row from left to right, the pipe radius r of each throat pipe 12 from top to bottom is ; ; ; ; Among the four throat pipes 12 in the third row from left to right, the pipe radius r of each throat pipe 12 from top to bottom is ; ; ; ; Among the four throat pipes 12 in the fourth row from left to right, the pipe radius r of each throat pipe 12 from top to bottom is ; ; ; .

[0073] When the square local resonance broadband sound absorbing panel is used, Figure 6 As shown, it can absorb The noise in the frequency band is especially The noise absorption effect in this frequency band is particularly excellent, and the inner holes of the throat 12 are all ordinary holes, which have strong durability in engineering applications, are easy to clean, have a long service life, and have low manufacturing difficulty and cost, which facilitates quantitative manufacturing.

[0074] Based on the above embodiment, step S2 includes:

[0075] S21: Set the pipe radius r of the throat 12 according to the requirements, and set the volume of the square resonance cavity 131 according to the requirements , and then according to Determine the equivalent length of the throat 12 ;

[0076] Or, S211: Set the pipe radius r of the throat pipe 12 according to the requirements, and set the equivalent length of the throat pipe 12 according to the requirements , and then according to Determine the volume of the square resonant cavity 131 .

[0077] In order to prevent blockage and / or reduce manufacturing difficulty, in this step, the pipe radius r of the throat 12 is first set, and then the volume of the square resonance cavity 131 is set under the premise of meeting the thickness requirements of the sound absorbing unit 1. and the equivalent length of the throat 12 One of them can be achieved through Determine the volume of the square resonant cavity 131 and the equivalent length of the throat 12 Another one of them is arranged in this way, which facilitates the manufacture of a square-shaped local resonance broadband sound absorption panel with a pipe radius of the throat pipe 12 that meets the requirements.

[0078] On the basis of the above embodiment, step S21 and step S211 include: the pipe radius r of the plurality of throat pipes 12 is greater than or equal to 0.5 mm.

[0079] After this step, in step S21 and step S211, when the pipe radius r of the throat 12 is set according to requirements, the pipe radius r of all or part of the throats 12 of the sound absorbing unit 1 is set to be greater than or equal to 1 mm. In this way, the square-shaped local resonance broadband sound absorbing panel manufactured is easy to clean, which is conducive to extending its service life.

[0080] On the basis of the above embodiment, step S21 includes: the size of the plurality of square resonant cavities 131 is the same. In step S21, the volume of the square resonant cavity 131 is set according to the requirements. When setting the depth, cross-sectional width and length of each square resonance cavity 131 in the sound absorbing unit 1 to be the same, such a design is conducive to manufacturing a regular square-shaped local resonance broadband sound absorbing panel, which is easy to use.

[0081] Based on the above embodiment, step S21 and step S211 include:

[0082] Step S2111: According to , get the pipe cross-sectional area of ​​the throat 12 、Square resonant cavity 131 volume Equivalent length to throat 12 The remaining one in .

[0083] Through step S2111, the preset frequency noise can be absorbed to the greatest extent, which is beneficial to improving the noise reduction effect of the square-shaped local resonance broadband sound absorption panel manufactured by the design method.

[0084] In addition to the above-mentioned design method of the square local resonance broadband sound absorption panel, the present invention also provides a square local resonance broadband sound absorption panel manufactured by the design method disclosed in the above-mentioned embodiment, the square local resonance broadband sound absorption panel includes a plurality of sound absorption units 1; the sound absorption unit 1 includes a sound absorption plate body 11, a plurality of throats 12, and a sound absorption body 13 having a plurality of square resonance cavities 131 arranged in an array; the sound absorption plate body 11 is covered at one end of the sound absorption body 13 to close the corresponding end opening of the square resonance cavity 131; the sound absorption plate body 11 has a sound absorption hole, the sound absorption hole is connected to the corresponding square resonance cavity 131, the throat 12 is installed on the sound absorption plate body 11, and the throat 12 is connected to the corresponding square resonance cavity 131 and the external environment of the sound absorption unit 1 through the corresponding sound absorption hole, the inner diameter of the sound absorption hole is equal to the pipe radius of the corresponding throat 12; the dimensions of the interconnected sound absorption hole, throat 12 and square resonance cavity 131 meet .

[0085] Regarding the sound absorbing unit 1, the sound absorbing body 13 is a grid-shaped frame structure, such as Figure 3 As shown, the frame structure has a plurality of square resonant cavities 131 arranged in an array; furthermore, as shown Figure 2 As shown, the sound absorbing plate body 11 is covered on the right end of the sound absorbing body 13 to close the right end opening of the grid-shaped sound absorbing body 13, and a through hole is opened on the sound absorbing plate body 11 along its thickness direction as a sound absorbing hole. The throat 12 is installed on the sound absorbing plate body 11, and the throat 12 can connect the corresponding square resonance cavity 131 in the sound absorbing unit 1 and the external environment of the sound absorbing unit 1 located on one side of the sound absorbing plate body 11, so that noise can be transmitted through the throat 12 into the square resonance cavity 131 to achieve the sound absorption function, and according to In the designed configuration of the sound absorbing unit 1 , the corresponding throat 12 cooperates with the square resonance cavity 131 to absorb noise of the corresponding frequency.

[0086] It should be noted that the specific type of the sound absorbing body 13 is not limited, as long as it can form the above-mentioned square resonance cavity 131. For example, in some specific embodiments, the sound absorbing body 13 can adopt a pultruded integrally formed structure, or in other specific embodiments, it can also adopt a structure in which several ribs are spliced ​​and bonded.

[0087] It should also be noted that the manner in which the throat tube 12 cooperates with the sound-absorbing body is not limited, as long as the above-mentioned functions can be achieved. For example, in some specific embodiments, the throat tube 12 is inserted into the sound-absorbing hole and sealed with the sound-absorbing hole by bonding or welding, and one end of the throat tube 12 extends into the corresponding square resonance cavity 131, and the other end is flush with the outer side surface of the sound-absorbing plate body 11. In this case, when the noise propagates, it will directly enter the inner cavity of the throat tube 12 and then propagate into the square resonance cavity 131; or, in other specific embodiments, one end of the throat tube 12 extends into the corresponding square resonance cavity 131, and the other end abuts against the sound-absorbing plate body 11 and seals with it by bonding or welding, and the throat tube 12 connects the corresponding square resonance cavity 131 and the corresponding sound-absorbing hole. In this case, when the noise propagates, it will first enter the sound-absorbing hole and then propagate into the corresponding square resonance cavity 131 through the corresponding throat tube 12.

[0088] It should also be noted that the shape of the sound-absorbing plate body 11 is not limited, as long as it can absorb noise in a preset frequency band. For example, in some specific embodiments, the sound-absorbing plate body 11 is a flat plate structure, or, in other specific embodiments, the sound-absorbing plate body 11 includes a flat plate portion and a tubular protrusion, and the flat plate portion is provided with a through hole connected to the protrusion. In this embodiment, the sound-absorbing hole is composed of the through hole on the flat plate portion and the central through hole of the protrusion; and the number and type of the sound-absorbing plate bodies 11 are not limited. For example, in some specific embodiments, the number of sound-absorbing plate bodies 11 is equal to the number of square resonance cavities 131, each sound-absorbing plate body 11 is provided with a sound-absorbing hole, and each sound-absorbing plate body 11 is covered at the end of the corresponding square resonance cavity 131, or, in other specific embodiments, such as Figure 2 and Figure 5 As shown, there is only one sound absorbing plate 11 , which covers the right end of the sound absorbing body 13 to close the right end openings of each square resonance cavity 131 of the sound absorbing body 13 .

[0089] The sound absorbing unit 1 is used to absorb noise in a preset frequency band, such as Figure 7 and Figure 8 As shown, a plurality of sound absorbing units 1 are arranged in an array when in use, so as to absorb noise of a preset frequency band that is propagated over a wide range.

[0090] It should be noted that the array arrangement of the sound absorbing units 1 is not limited, as long as the absorption of noise in the preset frequency band can be achieved, for example, Figure 7 As shown, in the adjacent upper and lower rows, the sides of the square resonance cavity 131 of the sound absorbing unit 1 are parallel, or, as shown in FIG. Figure 8 As shown, in two adjacent upper and lower rows, the top angles of the square resonance cavities 131 of adjacent sound absorbing units 1 are relatively equal.

[0091] Furthermore, in some specific embodiments, the grid-type local resonance broadband sound-absorbing panel further includes a back plate, a sealed cover of the sound-absorbing plate body 11 is provided on one end of the sound-absorbing main body 13, and a sealed cover of the back plate is provided on the other end of the sound-absorbing main body 13; furthermore, a plurality of sound-absorbing plate bodies 11 are provided on corresponding sound-absorbing main bodies 13, and a plurality of sound-absorbing units 1 are arranged in an array on the back plate. When in use, the back plate is bonded or riveted to the reflective surface of the device housing on the sound source side.

[0092] Of course, in other specific embodiments, in the grid-type local resonance broadband sound-absorbing panel, each of the plurality of sound-absorbing units 1 includes a corresponding sound-absorbing plate body 11 and a corresponding sound-absorbing body 13. The sound-absorbing plate body 11 covers one end of the corresponding sound-absorbing body 13, while the other end of the sound-absorbing body 13 is open. When in use, the plurality of sound-absorbing units 1 are arranged in an array in a device housing, and the open end of the sound-absorbing unit 1 is sealed with the device housing to achieve the sound absorption function.

[0093] Based on the above embodiment, the wall thickness of the structure between adjacent square resonance cavities 131 in the sound absorbing body 13 is 0.5 mm, the length of the throat 12 extending into the square resonance cavity 131 is 37.5 mm, the side length of the square resonance cavity 131 is 9 mm, and the depth of the square resonance cavity 131 is 49.5 mm. The sound absorbing plate 11 is a flat plate, and the thickness of the sound absorbing plate 11 is 0.5 mm. The number of square resonance cavities 131 is 25, and the square resonance cavities 131 are arranged in a 5×5 array, and the first row of square resonance cavities 131, the second row of square resonance cavities 131, the third row of square resonance cavities 131, the fourth row of square resonance cavities 131, and the fifth row of square resonance cavities 131 are arranged in sequence along the width direction of the sound absorbing body 13, and the square resonance cavities 131 in each row are arranged along the length direction of the sound absorbing body 13; the pipe radius r of the corresponding throat 12 inserted in the first row of square resonance cavities 131 is respectively 0.47mm, 0.48mm, 0.49mm, 0.53mm, 0.535mm; in the second row of square resonance cavities 131, the pipe radii r of the corresponding throats 12 are 0.545mm, 0.555mm, 0.585mm, 0.625mm, 0.675mm respectively; in the third row of square resonance cavities 131, the pipe radii r of the corresponding throats 12 are 0.725mm, 0.78mm respectively. , 0.84mm, 0.9mm, 0.95mm; in the fourth row of square resonance cavities 131, the pipe radii r of the corresponding throats 12 inserted are 0.99mm, 1.08mm, 1.15mm, 1.21mm, and 1.25mm respectively; in the fifth row of square resonance cavities 131, the pipe radii r of the corresponding throats 12 inserted are 1.35mm, 1.52mm, 1.67mm, 1.86mm, and 1.9mm respectively.

[0094] Specifically, such as Figure 2 and Figure 3 As shown, in one sound absorbing unit 1, the depth of the square resonance cavity 131 is 49.5 mm, the cross-sectional width and length of the square resonance cavity 131 are both 9 mm, the wall thickness of the layer between adjacent square resonance cavities 131 is 0.5 mm, the wall thickness of the outermost wall of several square resonance cavities 131 is 1.5 mm, the thickness of the flat sound absorbing plate body 11 is also 0.5 mm, and the length of the throat pipe 12 extending into the square resonance cavity 131 is 37.5 mm. In some specific embodiments, the total length of the throat pipe 12 is 38 mm, and a 0.5 mm long pipe section at one end of the throat pipe 12 is inserted into the sound absorbing plate body 11. In other specific embodiments, the total length of the throat pipe 12 is 37.5 mm, one end of the throat pipe 12 is located in the corresponding square resonance cavity 131, and the other end abuts and is sealed with the sound absorbing plate body 11, the centerline of the inner hole of the throat pipe 12 is collinear with the centerline of the corresponding sound absorbing hole, and the pipe radius r of the throat pipe 12 is equal to the radius of the corresponding sound absorbing hole.

[0095] Matching, such as Figure 2 As shown, among the five throats 12 in the first row from left to right, the pipe radii r of the throats 12 from top to bottom are r1=0.47mm; r2=0.48mm; r3=0.49mm; r4=0.53mm; r5=0.535mm; among the five throats 12 in the second row from left to right, the pipe radii r of the throats 12 from top to bottom are r6=0.545mm; r7=0.555mm; r8=0.585mm; r9=0.625mm; r10=0.0000mm; r11=0.0000mm; r12=0.0000mm; r13=0.0000mm; r14=0.0000mm; r15=0.0000mm; r16=0.0000mm; r17=0.0000mm; r18=0.0000mm; r19=0.0000mm; r20=0.0000mm; r21=0.0000mm; r22=0.0000mm; r33=0.0000mm; r44=0.0000mm; r55=0.0000mm; r6 10 =0.675mm; in the 5 throats 12 in the third row from left to right, the pipe radius r of each throat 12 from top to bottom is r 11 =0.725mm; r 12 =0.78mm; r 13 =0.84mm; r 14 =0.9mm; r 15 =0.95mm; in the 5 throats 12 in the fourth row from left to right, the pipe radius r of each throat 12 from top to bottom is r 16 =0.99mm; r 17 =1.08mm; r 18 =1.15mm; r 19 =1.21mm; r 20 =1.25mm; in the 5 throats 12 in the fifth row from left to right, the pipe radius r of each throat 12 from top to bottom is r 21 =1.35mm; r 22 =1.52mm; r 23 =1.67mm; r 24 =1.86mm; r 25 =1.9mm.

[0096] When the square local resonance broadband sound absorbing panel is used, Figure 4 As shown, it can efficiently absorb noise in the frequency band of 100Hz-500Hz, and the volume of the square local resonance broadband sound-absorbing panel is small, and most of the inner holes of the throat 12 are ordinary holes, which are easy to clean and have a long service life. In addition, the manufacturing difficulty and cost are low, and it is easy to mass-produce.

[0097] It should be noted that the type of the sound absorbing unit 1 is not limited, such as a metal part. Preferably, the sound absorbing unit 1 is an aramid part or a plastic part. Such a configuration is beneficial for reducing the weight of the square local resonance broadband sound absorbing panel while extending the service life of the square local resonance broadband sound absorbing panel.

[0098] Based on the above embodiment, the corners of the square resonant cavities 131 are rounded, and in two adjacent rows of square resonant cavities 131, the rounded corners of the square resonant cavities 131 in one row are located in the middle of the side surfaces of the corresponding square resonant cavities 131 in the other row.

[0099] like Figure 9 As shown, the corners of the square resonance cavities 131 are designed to be rounded, and the rounded corners of the upper row of square resonance cavities 131 are located in the middle of the lower row and the adjacent square resonance cavities 131. With this arrangement, the sound absorbing unit 1 can not only meet the noise reduction requirements, but also avoid the saddle effect, which is beneficial to extending the service life of the square local resonance broadband sound absorbing panel manufactured by this design method, and is beneficial to meeting the spatial curved surface modeling requirements of the sound absorbing panel.

[0100] Preferably, the side lengths of the square resonance cavities 131 of the sound absorbing unit 1 are equal, and the radius of the fillets at the corners of the square resonance cavities 131 are equal, which is conducive to controlling the volume of each square resonance cavity 131. , and is conducive to reducing the difficulty of manufacturing square-shaped local resonance broadband sound-absorbing panels.

[0101] On the basis of the above embodiment, the sound absorbing unit 1 is an aramid frame structure formed by roller rubber stretching. The roller rubber stretching forming process facilitates the manufacture of a sound absorbing unit 1 with a thinner wall thickness. The aramid frame structure is adopted, and the sound absorbing unit 1 is light in weight, which is conducive to the mass production of the sound absorbing unit 1 and has an excellent noise reduction effect.

[0102] In addition to the above-mentioned square-shaped local resonant broadband sound-absorbing panel and its design method, the present invention also provides a noise reduction shell including the square-shaped local resonant broadband sound-absorbing panel disclosed in the above embodiment. The noise reduction shell also includes a shell body. The above-mentioned square-shaped local resonant broadband sound-absorbing panel is arranged on the reflective surface of the shell body on the side of the sound source. Please refer to the existing technology for the structure of other parts of the noise reduction shell, which will not be repeated here.

[0103] Optionally, since noise during the operation of a large part of the equipment generally comes from the machinery running inside the equipment, a square-shaped local resonance broadband sound absorption panel can be set on the inner surface of the shell body.

[0104] For example, in some specific embodiments, the gear assembly inside the mechanical processing equipment will generate noise during operation, and the square local resonance broadband sound absorbing panel is provided on the inner surface of the shell body to absorb the medium and low frequency noise originating from the inside of the mechanical processing equipment, and the noise reduction shell in this embodiment may refer to the housing of the gear box in the mechanical processing equipment or the outer casing of the mechanical processing equipment, etc.; or, in other specific embodiments, the wheelset of the rail vehicle will generate noise during operation, and the square local resonance broadband sound absorbing panel is provided on the inner surface of the shell body to absorb the medium and low frequency noise generated by the wheelset, and the noise reduction shell in this embodiment may refer to the skirt panel.

[0105] Optionally, for some products that need to be protected from the influence of external noise, a square local resonance broadband sound-absorbing panel may be disposed on the outer surface of the shell body.

[0106] It should be noted that the noise reduction housing is not limited to being used in the above-mentioned example devices, as long as it can meet the noise reduction requirements of the devices.

[0107] It should also be noted that the connection method between the square local resonant broadband sound absorbing panel and the shell body is not limited, as long as the noise reduction requirements can be met. For example, in some specific embodiments, one end of the sound absorbing body of the square local resonant broadband sound absorbing panel is sealed with a sound absorbing plate body, and the other end is open. The open end of the sound absorbing body 13 is sealed and arranged on the shell body by bonding or welding. That is, in this embodiment, the square resonance cavity 131 is blocked by the shell body; or, in other specific embodiments, one end of the sound absorbing body 13 of the square local resonant broadband sound absorbing panel is sealed with a sound absorbing plate body, and the other end is sealed with a back plate. The back plate can be fixed to the shell body by screws or rivets.

[0108] It should be noted that the relational terms such as "first" and "second" mentioned above are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities; the "upper surface, lower surface, top, bottom" and the directional words "up, down, left, right" mentioned above are all defined based on the drawings in the specification.

[0109] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0110] The above describes in detail the grid-shaped local resonant broadband sound-absorbing panel and design method, as well as the noise-reducing housing, provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A design method for a square local resonance broadband sound absorption panel, characterized in that: The square local resonance broadband sound absorption panel comprises a plurality of sound absorption units (1), wherein the sound absorption unit (1) is a frame structure having a plurality of square resonance cavities (131) arranged in an array and a plurality of throats (12), wherein the throats (12) are mounted on the end wall of the first end of the square resonance cavity (131) and communicate with the external environment of the sound absorption unit (1) and the corresponding square resonance cavity (131); The design method includes: S1: Get the angular frequency of the sound wave , speed of sound , acoustic impedance , and obtain the pipe cross-sectional area of ​​the throat (12) 、Square resonant cavity (131) volume Equivalent length of throat (12) Both of them; S2: According to the sound wave angular frequency , the speed of sound , the acoustic impedance and the pipe cross-sectional area of ​​the throat (12) The volume of the square resonance cavity (131) is and the equivalent length of the throat (12) to obtain the pipe cross-sectional area of ​​the throat (12) The volume of the square resonance cavity (131) is and the equivalent length of the throat (12) The remaining one in .

2. The design method of the grid-type local resonance broadband sound-absorbing panel according to claim 1, characterized in that: The S2 includes: according to , the pipe cross-sectional area of ​​the throat (12) is obtained The volume of the square resonance cavity (131) is and the equivalent length of the throat (12) The remaining one of Where: is the target acoustic impedance; j is the imaginary unit; is the angular frequency of the sound wave of the noise in the target frequency band; is the speed of sound when noise propagates in air; is the equivalent length of the throat (12), and , L is the length of the throat pipe (12) inserted into the square resonance cavity (131), is the path length of the noise propagating into the pipe section of the throat pipe (12) located in the square resonance cavity (131), and r is the pipe radius of the throat pipe (12); is the pipe cross-sectional area of ​​the throat (12), and ; is the volume of the square resonance cavity (131), , H is the depth of the square resonance cavity (131); and b is the side length of the square resonance cavity (131).

3. The design method of the grid-type local resonance broadband sound-absorbing panel according to claim 1, characterized in that: The S2 includes: S21: Setting the pipe radius r of the throat (12) according to requirements, and setting the volume of the square resonance cavity (131) according to requirements , and then according to the Determine the equivalent length of the throat (12) ; Or, S211: setting the pipe radius r of the throat pipe (12) according to the requirements, and setting the equivalent length of the throat pipe (12) according to the requirements , and then according to the Determine the volume of the square resonant cavity (131) .

4. The design method of the grid-type local resonance broadband sound-absorbing panel according to claim 3, characterized in that: The S21 and S211 include: The pipe radius r of some of the throats (12) is greater than or equal to 0.5 mm.

5. The design method of the grid-type local resonance broadband sound-absorbing panel according to claim 3, characterized in that: The S21 includes: The dimensions of the plurality of square resonance cavities (131) are the same.

6. The design method of the grid-type local resonance broadband sound-absorbing panel according to claim 3, characterized in that: The S21 and S211 include: S2111: According to , get the pipe cross-sectional area of ​​the throat (12) 、Square resonant cavity (131) volume Equivalent length of throat (12) The remaining one in .

7. A square local resonance broadband sound absorbing panel, characterized in that: The square-shaped local resonance broadband sound-absorbing panel is manufactured by the design method of any one of claims 1 to 6, comprising a plurality of sound-absorbing units (1); The sound absorbing unit (1) comprises a sound absorbing plate (11), a plurality of throats (12), and a sound absorbing body (13) having a plurality of square resonance cavities (131) arranged in an array. The sound absorbing plate (11) is covered on one end of the sound absorbing body (13) to close the corresponding end opening of the square resonance cavity (131); The sound absorbing plate body (11) has a sound absorbing hole, the sound absorbing hole is connected to the corresponding square resonance cavity (131), the throat pipe (12) is installed on the sound absorbing plate body (11), and the throat pipe (12) is connected to the corresponding square resonance cavity (131) and the external environment of the sound absorbing unit (1) through the corresponding sound absorbing hole, and the inner diameter of the sound absorbing hole is equal to the pipe radius of the corresponding throat pipe (12); The sizes of the mutually connected sound absorbing holes, the throat (12) and the square resonance cavity (131) meet the requirements of .

8. The square local resonance broadband sound absorbing panel according to claim 7, characterized in that: The wall thickness of the structure between adjacent square resonance cavities (131) in the sound absorbing body (13) is 0.5 mm, the length of the throat (12) extending into the square resonance cavity (131) is 37.5 mm, the side length of the square resonance cavity (131) is 9 mm, and the depth of the square resonance cavity (131) is 49.5 mm, the sound absorbing plate body (11) is a flat plate, and the thickness of the sound absorbing plate body (11) is 0.5 mm; The number of the square resonance cavities (131) is 25, and a plurality of the square resonance cavities (131) are arranged in a 5×5 array, and the square resonance cavities (131) in the first row, the square resonance cavities (131) in the second row, the square resonance cavities (131) in the third row, the square resonance cavities (131) in the fourth row, and the square resonance cavities (131) in the fifth row are arranged in sequence along the width direction of the sound absorbing body (13), and a plurality of the square resonance cavities (131) in each row are arranged along the length direction of the sound absorbing body (13); In the first row of the square resonance cavities (131), the pipe radii r corresponding to the throat pipes (12) are inserted in order of 0.47 mm, 0.48 mm, 0.49 mm, 0.53 mm, and 0.535 mm; In the second row of the square resonance cavity (131), the pipe radii r corresponding to the throat pipe (12) are inserted in order of 0.545 mm, 0.555 mm, 0.585 mm, 0.625 mm, and 0.675 mm; In the third row of the square resonance cavity (131), the pipe radii r corresponding to the throat pipe (12) are inserted in order of 0.725 mm, 0.78 mm, 0.84 mm, 0.9 mm, and 0.95 mm; In the fourth column of the square resonance cavity (131), the pipe radii r corresponding to the throat pipe (12) are inserted in order of 0.99 mm, 1.08 mm, 1.15 mm, 1.21 mm, and 1.25 mm; In the square resonance cavity (131) of the fifth column, the pipe radii r of the corresponding throat pipes (12) are 1.35 mm, 1.52 mm, 1.67 mm, 1.86 mm, and 1.9 mm, respectively.

9. The square local resonance broadband sound absorbing panel according to claim 7, characterized in that: The corners of the square resonance cavities (131) are rounded, and in two adjacent rows of the square resonance cavities (131), the rounded corners of the square resonance cavities (131) in one row are located in the middle of the side surfaces of the corresponding square resonance cavities (131) in the other row.

10. The grid-type local resonance broadband sound-absorbing panel according to claim 7, characterized in that: The sound absorbing unit (1) is an aramid frame structure formed by roller rubber stretching.

11. A noise reduction housing, comprising a housing body, characterized in that: It also includes the square local resonance broadband sound absorbing panel according to any one of claims 7 to 10, wherein the square local resonance broadband sound absorbing panel is arranged on the reflecting surface of the shell body on the side of the sound source.

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