Acoustic superstructure cells, acoustic superstructure gradient aperture cells and sound absorbing structures

Abstract

The present invention discloses an acoustic superstructure cell, an acoustic superstructure gradient aperture cell and a sound absorbing structure. The acoustic superstructure cell comprises a micro-perforated plate and a polygonal labyrinth cavity arranged with a plurality of partitions. The top of the polygonal labyrinth cavity is fixedly connected to the lower surface of the micro-perforated plate, and the bottom of the polygonal labyrinth cavity is a solid. The sound wave enters the structure from the first hole on the micro-perforated plate, and forms a resonance cavity with the first hole and the first layer of the labyrinth cavity, and forms a sound absorbing cavity with the second hole and the labyrinth cavity thereafter. The broadband and thin sound absorbing structure is composed of a plurality of acoustic superstructure gradient aperture cells closely laid. The acoustic superstructure gradient aperture cell is composed of a plurality of acoustic superstructure cells closely arranged in the same row without spacing. The broadband and thin sound absorbing structure can not only realize continuous broadband sound absorption, but also reduce the thickness of the structure without changing the sound absorption effect, thereby overcoming the shortcomings of the prior art sound absorbing structure, which has a narrow sound absorption band, a large structure thickness and poor engineering applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical noise control, in particular to an acoustic superstructure cell, an acoustic superstructure gradient aperture cell and a sound absorbing structure. Background Art

[0002] In the industrial field, the noise generated by mechanical equipment not only increases the power consumption of equipment and accelerates the aging of equipment, but also causes sound pollution to the environment, seriously affecting people's daily production and life. Therefore, it is necessary to control noise. The control of noise is mainly studied from three aspects: noise source, noise propagation path and noise receiver. Among them, controlling noise in the propagation path is currently the most powerful means. Moreover, the sound-absorbing structure that can effectively hinder the propagation of noise has always been a research hotspot for noise control in recent years. According to the law of mass density and the law of stiffness, low-frequency noise requires a large structural thickness to achieve the purpose of sound absorption, which is difficult to achieve in practical engineering applications. However, the emergence of acoustic superstructures has solved this problem well. Acoustic superstructures can control large-wavelength, low-frequency elastic waves with small-sized structures, break the law of mass density, and realize the function of low-frequency sound wave control. Therefore, acoustic superstructures with extraordinary physical properties are an ideal solution to the problem of noise pollution. However, the mutual restriction between the wide-band sound absorption and thin structural thickness of acoustic superstructures is the key factor restricting its development.

[0003] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0004] In view of the shortcomings of the existing acoustic superstructures, such as the narrow sound absorption frequency band and the excessive structural thickness, the present invention proposes an acoustic superstructure cell, an acoustic superstructure gradient aperture cell and a sound absorption structure, which can not only achieve continuous broadband sound absorption, but also reduce the structural thickness without changing the sound absorption effect.

[0005] The objective of the present invention is achieved through the following technical solution: an acoustic superstructure cell comprises:

[0006] A micro-perforated plate having an upper surface and a lower surface, wherein the micro-perforated plate has first holes extending through the upper surface and the lower surface;

[0007] A polygonal labyrinth cavity is fixed to the lower surface, wherein the polygonal labyrinth cavity is a hollow cavity, and the hollow cavity comprises a polygonal bottom relative to the lower surface and a side wall extending vertically from the bottom to the lower surface;

[0008] A plurality of partitions are arranged on the hollow cavity to divide the cavity into a plurality of chambers. The partitions are provided with a second hole. Sound waves enter the hollow cavity from the first hole and form a resonance cavity with the first layer of the cavity of the hollow cavity. The sound waves and the second hole and the hollow cavity behind it form a sound absorption cavity.

[0009] In the acoustic superstructure cell, the propagation mode of the sound wave in the maze cavity is umbrella-shaped opening and closing propagation, stacked bending propagation or spiral winding propagation.

[0010] In the acoustic superstructure cell, the cross-section of the polygonal maze cavity is in the shape of one or more combinations of triangles, quadrilaterals, hexagons and octagons that can be densely tiled into a plane.

[0011] In the acoustic superstructure cell, the first hole is relatively located on the left side, the center or the right side of the cross section of the polygonal maze cavity.

[0012] In the acoustic superstructure cell, a plurality of partitions are arranged at equal intervals or variable intervals in the polygonal maze cavity, and the plurality of partitions are arranged at alternating intervals to divide the hollow cavity into spatial curled maze cavities.

[0013] In the acoustic superstructure cell, the partitions in the polygonal maze cavity are in the shape of a hexagon, a heptagon, a circle, a spiral, or a combination thereof.

[0014] In the acoustic superstructure cell, the aperture of the second hole opened on the partition or the size of the second hole remaining in the labyrinth cavity after the partition is inserted matches the aperture of the first hole opened on the corresponding micro-perforated plate.

[0015] An acoustic superstructure gradient aperture cell comprises n acoustic superstructure cells arranged adjacent to each other in the same row, the polygonal maze cavity of the i-th acoustic superstructure cell is closely connected with the polygonal maze cavity of the i+1-th acoustic superstructure cell, i=1, 2, ..., n-1, and n is a positive integer greater than or equal to 2.

[0016] In the acoustic superstructure gradient aperture cell, n acoustic superstructure cells share the same micro-perforated plate, and the aperture of the first hole increases or decreases sequentially.

[0017] In the acoustic superstructure gradient aperture cell, the side lengths of the polygonal cavity sections of n acoustic superstructure cells are the same, or the side lengths of the polygonal cavity sections of the first acoustic superstructure cell to the nth acoustic superstructure cell arranged in sequence increase, decrease or change randomly.

[0018] In the acoustic superstructure gradient aperture cell, the labyrinth cavity depths of n acoustic superstructure cells are the same; or, the labyrinth cavity depths of the first acoustic superstructure cell to the nth acoustic superstructure cell arranged in sequence increase, decrease or change irregularly and randomly.

[0019] In the acoustic superstructure gradient aperture cell, the labyrinth cavities of the n acoustic superstructure cells are not connected to each other.

[0020] A sound absorbing structure comprises m closely packed acoustic superstructure gradient aperture cells, the polygonal labyrinth cavity of the jth acoustic superstructure cell is closely connected with the labyrinth cavity of the j+1th acoustic superstructure cell, j=1, 2, ..., m-1, m is a positive integer greater than or equal to 2.

[0021] In the sound absorbing structure, the first holes share the same micro-perforated plate, and the apertures of the first holes increase or decrease sequentially.

[0022] In the sound absorbing structure, the side lengths of the polygonal cavity sections of the m acoustic superstructure gradient aperture cells are the same;

[0023] Alternatively, the side lengths of the polygonal cavity cross sections of the first acoustic superstructure gradient aperture cell to the mth acoustic superstructure gradient aperture cell that are densely laid in sequence increase, decrease, or change randomly without rules.

[0024] In the sound absorbing structure, the labyrinth cavity depths of m acoustic superstructure gradient aperture cells are the same; or, the labyrinth cavity depths of the first acoustic superstructure gradient aperture cell to the mth acoustic superstructure gradient aperture cell, which are densely laid in sequence, increase, decrease, or change randomly without rules.

[0025] In the sound absorbing structure, the labyrinth cavities of the m acoustic superstructure gradient aperture cells are not connected to each other.

[0026] Compared with the prior art, the present invention has the following advantages: the acoustic superstructure cell provided by the present invention has excellent sound absorption performance at low frequency and lightness. An acoustic superstructure gradient aperture cell can be formed by arranging multiple acoustic superstructure cells in the same row without spacing. A plurality of acoustic superstructure gradient aperture cells are densely laid together to form a broadband and thin sound absorption structure. The sound absorption structure can not only improve the disadvantage of narrow low-frequency sound absorption bandwidth and achieve continuous broadband sound absorption by sequentially increasing or decreasing the aperture of the first hole on the micro-perforated plate so that different sound absorption peaks are arranged and coupled in sequence, but also further utilize the band gap characteristics of the densely laid structure to further broaden the sound absorption frequency band. The honeycomb maze cavity of the sound absorption structure adopts umbrella-shaped opening and closing, layered bending, or spiral winding and other sound wave propagation methods to extend the propagation path of the sound wave in the cavity, thereby reducing the thickness of the structure without changing the sound absorption effect. The sound-absorbing structure can achieve the purpose of sound absorption in different frequency bands by adjusting the internal structural parameters of the cells and the arrangement of the cells without changing the external structure of the cells and making full use of the sound-absorbing space. It overcomes many shortcomings of traditional sound-absorbing structures, such as narrow sound absorption frequency band, large structural thickness, and poor engineering applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] By reading the detailed description of the preferred specific embodiments below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of illustrating the preferred embodiments and are not considered to be limitations of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0028] In the attached picture:

[0029] FIG1(a) is a schematic diagram of the structure of an acoustic superstructure cell; FIG1(b) is a schematic diagram of the structure of a honeycomb maze cavity in an acoustic superstructure cell;

[0030] FIG2(a) is a schematic diagram of the structure of an acoustic superstructure cell; FIG2(b) is a schematic diagram of the structure of a honeycomb maze cavity in an acoustic superstructure cell;

[0031] FIG3(a) is a schematic diagram of the structure of an acoustic superstructure cell; FIG3(b) is a schematic diagram of the structure of a honeycomb maze cavity in an acoustic superstructure cell;

[0032] Figure 4(a) to Figure 4(d) Schematic diagrams of different cavity cross-sectional shapes, where FIG4(a) is a triangular honeycomb, FIG4(b) is a quadrilateral honeycomb, FIG4(c) is a hexagonal honeycomb, and FIG4(d) is a combined honeycomb of an octagon and a square;

[0033] Figure 5(a) to Figure 5(e) Schematic diagrams of different baffle shapes, wherein FIG5(a) and FIG5(b) are baffles used in a broadband light and thin sound absorbing structure that propagates sound waves in an umbrella-like manner, FIG5(c) is a baffle used in a broadband light and thin sound absorbing structure that propagates sound waves in a stacked and curved manner, and FIG5(d) and FIG5(e) are baffles used in a broadband light and thin sound absorbing structure that propagates sound waves in a spirally coiled manner;

[0034] FIG6(a) is a cross-sectional view of an acoustic superstructure cell in which baffles are arranged at equal intervals; FIG6(b) is a cross-sectional view of an acoustic superstructure cell in which baffles are arranged at variable intervals;

[0035] Figure 7 Schematic diagram of the structure of the acoustic superstructure gradient aperture cell;

[0036] Figure 8 It is a cross-sectional view of the acoustic superstructure gradient aperture cell;

[0037] Fig. 9 It is a cross-sectional view of the acoustic superstructure gradient aperture cell;

[0038] Fig.10 It is a cross-sectional view of the acoustic superstructure gradient aperture cell;

[0039] Fig.11 It is a schematic diagram of the structure of a broadband and thin sound absorbing structure;

[0040] Fig.12 It is a schematic diagram of the structure of a broadband and thin sound-absorbing structure;

[0041] Fig.13 It is a schematic diagram of the structure of a broadband and thin sound-absorbing structure;

[0042] In the figure: 1 micro-perforated plate; 2 labyrinth cavity; 3 the first hole on the micro-perforated plate; 4 partition plate; 5 the second hole at the partition plate.

[0043] The present invention is further explained below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0044] The following will refer to the attached Figure 1(a) to Figure 13 Specific embodiments of the present invention are described in more detail. Although specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0045] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0046] To facilitate understanding of the embodiments of the present invention, further explanation will be given below by taking specific embodiments as examples in conjunction with the accompanying drawings, and each of the accompanying drawings does not constitute a limitation on the embodiments of the present invention.

[0047] like Figure 1(a) to Figure 13 As shown, in order to better understand the present invention, it is specifically described through embodiments.

[0048] Example 1: Broadband, lightweight sound-absorbing structure that spreads sound waves in an umbrella-like manner

[0049] like Figure 1(a) to Figure 1(b) As shown, this embodiment provides an acoustic superstructure cell, which includes: a micro-perforated plate 1 and a polygonal maze cavity 2 arranged with a plurality of partitions 4, the top of the polygonal maze cavity 2 is fixedly connected to the lower surface of the micro-perforated plate 1, the bottom of the polygonal honeycomb maze cavity is a solid, and a plurality of partitions 4 divide the honeycomb maze cavity into a plurality of small chambers.

[0050] The sound wave enters the structure from the first hole 3 on the micro-perforated plate 1, and forms a resonance cavity with the first hole 3 and the first layer of the polygonal labyrinth cavity 2, and forms a sound absorption cavity with the second hole 5 and the polygonal labyrinth cavity 2 behind it. Figure 1(a) to Figure 1(b) In the illustrated embodiment, the sound waves entering the first layer of small chambers of the polygonal maze cavity 2 diffuse to the two small holes on the outside of the first layer of partition 4 and propagate to the two sides of the second layer of small chambers, then converge to the small holes on the inside of the second layer of partition 4 and propagate to the third layer of small chambers, then diffuse to the two small holes on the outside of the third layer of partition 4 and propagate to the two sides of the fourth layer of small chambers, and so on, circulate and propagate to the last layer of small chambers.

[0051] In the present invention, the first hole 3 on the micro-perforated plate 1 is relatively located on the left side, the center or the right side of the cross section of the polygonal labyrinth cavity 2. Figure 1(a) to Figure 1(b) In the illustrated embodiment, the first hole 3 on the micro-perforated plate 1 is relatively located at the center of the cross section of the polygonal labyrinth cavity 2 .

[0052] The cross-sectional shape of the polygonal labyrinth cavity 2 in the present invention can be a triangle, a quadrilateral, a hexagon, an octagon, or one or more combinations thereof that can be closely laid out into a plane, so as to make full use of the sound absorption space, such as Figure 4(a) to Figure 4(d) As shown. Figure 1(a) to Figure 1(b) In the illustrated embodiment, the cross-sectional shape of the polygonal labyrinth cavity 2 is a hexagonal honeycomb, as shown in FIG. 4( c ).

[0053] The shape of the partition 4 in the polygonal labyrinth cavity 2 of the present invention can be a combination of a hexagon or a heptagon and a circle or a spiral, such as Figure 5(a) to Figure 5(e) The polygonal labyrinth cavity 2 is provided with a plurality of partitions 4 at equal intervals or variable intervals, and the plurality of partitions 4 are arranged at alternate intervals to divide the polygonal labyrinth cavity 2 into space curled labyrinth cavities, such as Figure 6(a) to Figure 6(b) As shown. Figure 1(a) to Figure 1(b) In the illustrated embodiment, the shape of the partition 4 is a combination of a hexagon and a circle, and as shown in FIG. 5( a ) and FIG. 5( b ), nine partitions 4 are arranged at intervals in the polygonal maze cavity 2 and divide the polygonal maze cavity 2 into 10 small chambers.

[0054] In the present invention, the aperture of the second hole 5 opened on the partition 4 or the size of the second hole 5 remaining in the polygonal labyrinth cavity 2 after the partition 4 is inserted matches the aperture of the first hole 3 opened on the corresponding micro-perforated plate 1. The aperture range of the first hole is between 0.2 and 1 mm, and the aperture range of the second hole is between 0.2 and 2 mm. Apertures less than or equal to 1 mm are considered micro-perforations. The resonance cavity is related to the aperture, and the interaction between the two jointly affects the sound absorption frequency and peak value, and thus affects the sound absorption bandwidth. The small holes on the micro-perforated plate and the first layer of the polygonal labyrinth cavity below form a resonance cavity, and continuous broadband sound absorption can be achieved by changing the aperture. The small holes at the partition and the cavity behind it form a sound absorption cavity. When the sound wave frequency is close to the natural frequency at the small hole, the fluid at the small hole can achieve resonant sound absorption. In the present invention, the propagation mode of sound waves in the honeycomb polygonal labyrinth cavity 2 can be umbrella-shaped opening and closing propagation, stacked bending propagation, or spiral winding propagation. Figure 1(a) to Figure 1(b) In the illustrated embodiment, the propagation mode of the sound wave in the honeycomb polygonal labyrinth cavity 2 is umbrella-like opening and closing propagation.

[0055] Reference Figure 7 and Figure 8 The present invention provides an acoustic superstructure gradient aperture cell, comprising n acoustic superstructure cells mentioned above arranged closely in the same row, the polygonal maze cavity 2 of the i-th acoustic superstructure cell is closely connected with the polygonal maze cavity 2 of the i+1-th acoustic superstructure cell, i=1, 2,..., n-1, n is a positive integer greater than or equal to 2, the polygonal maze cavities 2 of the n acoustic superstructure cells are not connected to each other, the n first holes 3 on the micro-perforated plate 1 share the same micro-perforated plate 1, and the apertures of the first holes 3 increase or decrease sequentially. Figure 7 and Figure 8 In this example, n is 10.

[0056] In the acoustic superstructure gradient aperture cell of the present invention, the cross-sectional side length and depth of the polygonal maze cavity 2 of the n acoustic superstructure cells may be the same or different, for example, increasing, decreasing or changing randomly without rules. In this embodiment, the cross-sectional side length and depth of the polygonal maze cavity 2 of the n acoustic superstructure cells are the same.

[0057] Reference Fig.11 The present invention provides a broadband and thin sound absorbing structure, comprising m closely-packed acoustic superstructure gradient aperture cells, the honeycomb cavity of the jth acoustic superstructure cell is closely connected with the honeycomb cavity of the j+1th acoustic superstructure cell, j=1, 2, ..., m-1, m is a positive integer greater than or equal to 2, the polygonal maze cavities 2 of the m acoustic superstructure gradient aperture cells are not connected to each other, and the apertures of all the first holes 3 sharing the same micro-perforated plate 1 increase or decrease in sequence.

[0058] In the broadband and thin sound absorbing structure of the present invention, the cross-sectional side length and depth of the polygonal labyrinth cavity 2 of the m acoustic superstructure gradient aperture cells may be the same or different, for example, increasing, decreasing or changing randomly without rules. In this embodiment, the cross-sectional side length and depth of the polygonal labyrinth cavity 2 of the m acoustic superstructure gradient aperture cells are the same.

[0059] In the present invention, the sound wave forms an acoustic resonance effect in the first hole 3 on the micro-perforated plate 1 and the first layer of the polygonal labyrinth cavity 2, generating a sound absorption peak, and the refractive index is increased by propagating the sound wave in the polygonal labyrinth cavity 2 in an umbrella-like opening and closing manner, and the sound energy is converted into heat energy dissipation through the viscous resistance inside the fluid or the friction resistance generated by the interaction between the fluid and the solid, thereby further absorbing the sound energy and forming an acoustic absorption effect. By sequentially increasing or decreasing the aperture of the first hole 3 on the micro-perforated plate 1, different sound absorption peaks are sequentially arranged and coupled, so that continuous broadband sound absorption can be achieved, and the band gap characteristics of the densely packed structure can be further utilized to further broaden the sound absorption frequency band.

[0060] Example 2: Wide-bandwidth, lightweight sound-absorbing structure for stacked, curved sound wave propagation

[0061] This embodiment is basically the same as embodiment 1, except that: (1) the structural schematic diagram of the acoustic superstructure cell is shown in FIG2(a), the structural schematic diagram of the honeycomb maze cavity in the acoustic superstructure cell is shown in FIG2(b), and the first hole 3 on the microperforated plate 1 is relatively located on the right side of the cross section of the polygonal maze cavity 2; (2) the sound wave from the first hole 3 on the microperforated plate 1 enters the rightmost space of the first layer of small chambers of the honeycomb polygonal maze cavity 2 and propagates, then propagates to the left to the leftmost space and enters the leftmost space of the second layer of small chambers from the small hole at the partition 4 and propagates, then propagates to the right to the rightmost space and enters the rightmost space of the third layer of small chambers from the small hole at the partition 4 and propagates, and so on, the stacked bending cycle propagates from top to bottom to the last layer of small chambers; (3) the cross-sectional view of the acoustic superstructure gradient aperture cell is shown in FIG2(a). Fig. 9 As shown, the schematic diagram of the structure of the broadband thin sound absorption structure is as follows Fig.12 As shown, nine heptagonal partitions 4 are arranged at equal intervals in the polygonal labyrinth cavity 2, and the shape of the partition 4 is shown in FIG. 5( c ).

[0062] Example 3: Wide-bandwidth, lightweight sound-absorbing structure for spirally winding and propagating sound waves

[0063] This embodiment is basically the same as the embodiment 1, except that: (1) the schematic diagram of the structure of the acoustic superstructure cell is shown in FIG3(a), the schematic diagram of the structure of the honeycomb maze cavity in the acoustic superstructure cell is shown in FIG3(b), and the shape of the partition 4 in the polygonal maze cavity 2 is a combination of hexagonal, circular and spiral shapes, as shown in FIG5(d) and FIG5(e); (2) the sound wave from the first hole 3 on the micro-perforated plate 1 enters the innermost space of the first layer of small chambers of the honeycomb polygonal maze cavity 2 and propagates, then spirals from the inside to the outside to propagate to the outermost space and enters the outermost space of the second layer of small chambers from the small holes on the partition 4 and propagates, then spirals from the outside to the inside to propagate to the innermost space and enters the innermost space of the next layer of small chambers from the small holes on the partition 4 and propagates in this way to the last layer of small chambers; (3) the cross-sectional view of the acoustic superstructure gradient aperture cell is shown in FIG. Fig.10 As shown, the schematic diagram of the structure of the broadband thin sound absorption structure is as follows Fig.13 As shown, nine partitions 4 are arranged at variable intervals in the polygonal labyrinth cavity 2 .

[0064] The sound absorbing structure of the present invention can not only realize continuous broadband sound absorption, but also reduce the structure thickness without changing the sound absorption effect, thus overcoming many shortcomings of traditional sound absorbing structures such as narrow sound absorption frequency band, large structure thickness, poor engineering applicability, etc.

[0065] All features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any way. Any feature disclosed in this specification (including any additional claims, abstracts and drawings), unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes. That is, unless otherwise stated, each feature is just an example of a series of equivalent or similar features. For example, the cross-sectional shape of the labyrinth cavity in the embodiment of the present invention is a hexagon, which can obviously be replaced by one or more combinations of squares, rhombuses, triangles, pentagons, octagons, etc. that can be densely laid into a plane.

[0066] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields, and the above specific embodiments are only illustrative and instructive, rather than restrictive. A person of ordinary skill in the art can also make many forms under the guidance of this specification and without departing from the scope of protection of the claims of the present invention, all of which belong to the protection of the present invention.

Claims

1. An acoustic superstructure cell, characterized in that: These include, A micro-perforated plate having an upper surface and a lower surface, wherein the micro-perforated plate has first holes extending through the upper surface and the lower surface; A polygonal labyrinth cavity is fixed to the lower surface, wherein the polygonal labyrinth cavity is a hollow cavity, and the hollow cavity comprises a polygonal bottom relative to the lower surface and a side wall extending vertically from the bottom to the lower surface; A plurality of partitions are arranged on the hollow cavity to divide it into a plurality of chambers, the partition is provided with a second hole, the sound wave enters the hollow cavity from the first hole and forms a resonance cavity with the first layer of the cavity of the hollow cavity, the sound wave and the second hole and the hollow cavity thereafter form a sound absorption cavity, when the sound wave frequency is close to the natural frequency at the small hole, the fluid at the small hole can achieve resonance sound absorption, the aperture of the second hole opened on the partition or the size of the second hole remaining after the partition is inserted into the polygonal maze cavity matches the aperture of the first hole opened on the corresponding micro-perforated plate, continuous broadband sound absorption can be achieved by changing the aperture, and the band gap characteristics of the densely laid structure are used to further widen the sound absorption frequency band, the aperture range of the first hole is between 0.2 and 1 mm, and the aperture range of the second hole is between 0.2 and 2 mm, a plurality of partitions are arranged in the polygonal maze cavity at equal intervals or variable intervals, and the plurality of partitions are arranged at alternating intervals to separate the hollow cavity into spatial curled maze cavities.

2. The acoustic superstructure cell according to claim 1, characterized in that: The propagation mode of the sound wave in the labyrinth cavity is umbrella-shaped opening and closing propagation, stacked bending propagation or spiral winding propagation.

3. The acoustic superstructure cell according to claim 1, characterized in that: The cross-section of the polygonal labyrinth cavity is in the shape of one or more combinations of triangles, quadrilaterals, hexagons and octagons that are closely laid out into a plane.

4. The acoustic superstructure cell according to claim 3, characterized in that: The first hole is relatively located on the left side, the center or the right side of the cross section of the polygonal labyrinth cavity.

5. The acoustic superstructure cell according to claim 1, characterized in that: The partitions in the polygonal labyrinth cavity are in the shape of hexagons, heptagons, circles, spirals and combinations thereof.

6. An acoustic superstructure gradient aperture cell, characterized in that: It comprises n acoustic superstructure cells according to any one of claims 1 to 5 arranged adjacent to each other in the same row, the polygonal maze cavity of the i-th acoustic superstructure cell is closely connected with the polygonal maze cavity of the i+1-th acoustic superstructure cell, i=1, 2,…, n-1, and n is a positive integer greater than or equal to 2.

7. The acoustic superstructure gradient aperture cell according to claim 6, wherein: The n acoustic superstructure cells share the same micro-perforated plate, and the apertures of the first holes increase or decrease sequentially.

8. A sound absorbing structure, characterized in that: It comprises m closely packed acoustic superstructure gradient aperture cells as described in any one of claims 6 to 7, the polygonal maze cavity of the jth acoustic superstructure cell is closely connected with the maze cavity of the j+1th acoustic superstructure cell, j=1, 2,…, m-1, m is a positive integer greater than or equal to 2.

Images