Sound insulation structure

Abstract

This invention relates to a sound insulation structure, comprising at least one sound insulation unit. Each sound insulation unit includes multiple layers of plates connected sequentially along a first direction. In any two adjacent layers, one is a porous material plate, and the other is a perforated plate. The perforated plate has at least one first through-hole for sound waves to pass through. This invention can effectively improve the sound insulation effect of the sound insulation structure against low-frequency noise, facilitating its promotion and application.

Description

Technical Field

[0001] This invention relates to the field of sound insulation technology, and in particular to a sound insulation structure. Background Technology

[0002] Low-frequency noise is a common form of noise in daily life, such as noise from substations, pump rooms, air-conditioned vehicles, and impact drills. Low-frequency noise is characterized by its strong penetrating power and long propagation distance, making it difficult to effectively control. Taking a single-layer wall as an example, a thin wall often results in insufficient sound insulation. To improve this, a common practice is to build a framework on the wall surface, forming a cavity of a certain thickness, and then sealing the framework with gypsum board to increase sound insulation. To further ensure sound insulation, sound-absorbing material can be filled into the cavity of the framework. This type of wall follows the mass law, which states that the greater the mass (or surface density) of a material, the greater its sound insulation and the better its sound insulation effect. Furthermore, the higher the sound frequency, the greater the sound insulation. However, when the sound frequency is very low, the sound insulation approaches zero. In other words, this type of wall has poor sound insulation performance for low-frequency sound waves and cannot meet the sound insulation requirements for low-frequency noise. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to improve the sound insulation effect of walls against low-frequency noise.

[0004] To solve the above-mentioned technical problems, the present invention provides a sound insulation structure, including at least one sound insulation unit. Each sound insulation unit includes multiple layers of plates connected sequentially along a first direction. In any two adjacent layers, one is a porous material plate and the other is a perforated plate. The perforated plate is provided with at least one first through hole for sound waves to pass through.

[0005] In one embodiment of the present invention, the ratio of the total area of ​​all first through holes in the perforated plate to the area of ​​the perforated plate is the perforation rate, and the perforation rate is denoted as S, then 0.001≤S≤0.5.

[0006] In one embodiment of the present invention, the perforation rate is denoted as S, and then 0.001≤S≤0.36.

[0007] In one embodiment of the present invention, the porosity of the porous material plate is 0.6 to 0.99.

[0008] In one embodiment of the present invention, the area of ​​each of the first through holes is not less than π / 4 mm².

[0009] In one embodiment of the invention, the acoustic impedance of the perforated plate is greater than that of air.

[0010] In one embodiment of the invention, each sound insulation unit includes multiple perforated panels, and all the perforated panels in each sound insulation unit have the same perforation rate; or, at least two of the perforated panels in each sound insulation unit have different perforation rates.

[0011] In one embodiment of the present invention, each sound insulation unit includes multiple layers of porous material plates, wherein all the porous material plates in each sound insulation unit have the same porosity; or, at least two of the porous material plates in each sound insulation unit have different porosities.

[0012] In one embodiment of the present invention, the sound insulation structure is placed in a corresponding environmental medium, the maximum frequency of the sound wave blocked by the sound insulation structure is a first frequency fm, the transmission wavelength of the sound wave at the first frequency in the environmental medium is a first wavelength λm, and the maximum size of the sound insulation unit is Lm, then Lm≤0.5λm;

[0013] In the sound insulation unit, the sum of the thicknesses of a porous material plate and a perforated plate is L1. The sound insulation unit is rectangular, and the length of its diagonal is L2. If L1 ≥ L2, then Lm = L1; if L2 > L1, then Lm = L2.

[0014] In one embodiment of the present invention, the thickness of the perforated plate is 1 to 20 mm, and the thickness of the porous material plate is 1 to 50 mm.

[0015] In one embodiment of the present invention, the first through hole is filled with a first filler, which is a porous material.

[0016] In one embodiment of the present invention, the perforated plate is made of any one of rubber, stone, plastic, wood, metal plate, fiberglass or carbon fiber; the porous material plate is made of any one of polyester fiber, rock wool, glass fiber, basalt fiber or foam material.

[0017] In one embodiment of the present invention, the sound insulation unit has a sound wave energy transmittance. Satisfy the following formula:

[0018]

[0019] in, The wavenumber of the sound waves in the sound insulation unit. The angular frequency of the sound wave. The velocity of sound in the sound insulation unit. This represents the sound loss of the sound insulation unit during sound wave propagation. This represents the thickness of the sound insulation unit; , , For the density of the environmental medium, The speed of sound in the ambient medium. This is the equivalent acoustic density of the sound insulation unit.

[0020] In one embodiment of the present invention, a plurality of sound insulation units are included, all of which are laid out in a flat manner, with no gap between adjacent sound insulation units.

[0021] The technical solution of the present invention has the following advantages compared with the prior art:

[0022] The sound insulation structure described in this invention can effectively improve the sound insulation effect of the sound barrier against low-frequency noise. It has a simple structure, is easy to process, and is convenient for promotion and application. Attached Figure Description

[0023] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the sound insulation structure of the present invention;

[0025] Figure 2 yes Figure 1 A schematic diagram of the sound insulation unit in the sound insulation structure shown.

[0026] Figure 3 This is an exploded view of the sound insulation unit in this invention;

[0027] Figure 4 This is a comparison chart of the sound insulation properties of porous material boards with different board densities;

[0028] Figure 5 This is a comparison chart of the sound insulation performance of porous material boards of different thicknesses;

[0029] Figure 6 This is a comparison chart of the sound insulation properties of different sound insulation structures;

[0030] Figure 7 This is a comparison chart of the sound insulation properties of different sound insulation structures over a wide frequency range;

[0031] Figure 8 This is a comparison diagram showing the sound insulation of the sound insulation unit of the present invention when using perforated plates with different perforation rates.

[0032] Figure 9 This is a comparison diagram of the sound insulation performance of sound insulation units of different thicknesses in this invention;

[0033] Figure 10 This is a comparison diagram of the sound insulation amount of each perforated plate in the sound insulation unit of the present invention when they have different perforation rates, and other cases.

[0034] Figure 11 This is a comparison diagram of the sound insulation of each porous material plate in the sound insulation unit of the present invention when different porosities are used, and other cases.

[0035] Figure 12 This is a comparison diagram of the sound insulation amount when the first through hole in the perforated plate of the sound insulation unit of the present invention is filled with porous material and other cases.

[0036] Explanation of reference numerals on the accompanying drawings:

[0037] 10. Sound insulation unit;

[0038] 101. Porous material plate;

[0039] 102. Perforated plate; 1021. First through hole. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present disclosure or its application or use.

[0041] In the description of this invention, it should be understood that the terms "vertical," "upper," "lower," "top," "side," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] Example 1

[0044] See Figures 1-3 This embodiment discloses a sound insulation structure, including at least one sound insulation unit 10, each sound insulation unit 10 including multiple layers of boards connected sequentially along a first direction;

[0045] In this structure, one of any two adjacent panels is a porous material panel 101 and the other is a perforated panel 102. The perforated panel 102 is provided with at least one first through hole 1021 for sound waves to pass through. That is, the porous material panel 101 and the perforated panel 102 in the sound insulation unit 10 are arranged alternately. This structure can effectively improve the low-frequency sound insulation effect of the sound insulation structure.

[0046] The first direction mentioned above refers to the thickness direction of the plate. In practical applications, it can also be the direction of sound wave propagation.

[0047] For example, the sound insulation unit 10 may have only two layers: a porous material board 101 and a perforated board 102, i.e., a two-layer structure of "porous material board 101 + perforated board 102"; or, the sound insulation unit 10 may have three layers, with the porous material board 101 and perforated board 102 arranged alternately, which can be "porous material board 101 + perforated board 102 + porous material board 101" or "perforated board 102 + porous material board 101 + perforated board 102"; or, the sound insulation unit 10 may have more layers, such as four, five or more layers, for example, a five-layer structure of "porous material board 101 + perforated board 102 + porous material board 101 + perforated board 102 + porous material board 101", as long as the porous material board 101 and perforated board 102 are arranged alternately.

[0048] The layers of the sound insulation unit 10 can be fixed together by adhesive bonding or by other methods.

[0049] In traditional sound insulation structures, a solid back panel (without perforations) is usually installed on the outer layer as a sound insulation board. For example, traditional wall structures use this form. The sound insulation of this traditional sound insulation structure follows the mass law, and the formula for the sound insulation mass law is as follows:

[0050] (1)

[0051] in For sound insulation, The angular frequency of the sound wave. For the quality of the sound insulation structure, For the density of the environmental medium, The speed of sound in the ambient medium;

[0052] Understandably, the "environmental medium" mentioned above refers to the environment in which the sound insulation structure is situated. For example, if the sound insulation structure is a typical building with walls, which is placed in the air medium, then the "environmental medium" refers to "air." Therefore, in the above formula... This refers to the mass of the wall. air density, Speed ​​of sound in air;

[0053] As can be seen from the above mass law formula, the sound insulation of traditional sound insulation structures mainly depends on the mass of the structure. The greater the mass (or the greater the surface density), the greater the sound insulation and the better the sound insulation effect. The higher the sound wave frequency, the greater the sound insulation. However, when the sound wave frequency is very low, the sound insulation approaches zero. Therefore, although traditional sound insulation structures have a certain sound insulation effect, their sound insulation effect is mainly reflected in the sound insulation of high-frequency sound waves, while the sound insulation effect for low-frequency sound waves is poor, and they cannot play a good role in low-frequency sound insulation. The sound insulation structure of this embodiment changes the structure of the sound insulation unit by using a method of alternating arrangement of porous material plates and perforated plates, so that each plate is a sound-permeable plate. This changes the traditional sound insulation concept and achieves a better low-frequency sound insulation effect on this basis. Moreover, it can have a good sound insulation effect in a wide frequency range, ensuring effective sound insulation in the low-frequency broadband range.

[0054] The principle by which the sound insulation structure in this embodiment achieves sound insulation is as follows:

[0055] In this embodiment, the sound insulation unit's energy transmittance to sound waves is... Satisfy the following formula:

[0056] (2)

[0057] in, The wavenumber of the sound waves in the sound insulation unit. The angular frequency of the sound wave. The velocity of sound in the sound insulation unit. This represents the sound loss of the sound insulation unit during sound wave propagation. This represents the thickness of the sound insulation unit; , , For the density of the environmental medium, The speed of sound in the ambient medium. This is the equivalent acoustic density of the sound insulation unit.

[0058] Understandably, the "environmental medium" mentioned above refers to the environment in which the sound insulation structure is situated. For example, if the sound insulation structure is a wall, which is placed in the air medium, then the "environmental medium" refers to "air." Therefore, in the above formula... air density, The speed of sound in air.

[0059] The term "energy transmittance" refers to the ratio of transmitted sound energy to incident sound energy when a sound wave passes through a sound insulation unit (such as a wall). The lower the energy transmittance, the better the sound insulation performance of the sound insulation unit; conversely, the higher the energy transmittance, the worse the sound insulation performance. If the energy transmittance is 1, the surface provides no sound insulation at all.

[0060] From the above formula, it can be seen that when the frequency of the sound wave is very low, it makes... When the term is extremely small and approaches 0, the above energy transmittance Then the following formula is satisfied:

[0061] (3)

[0062] In the sound insulation unit structure of this embodiment, due to the presence of loss terms... ,and , Therefore, energy transmittance This also shows that the sound insulation unit structure of this embodiment has a sound insulation amount that is not zero even for low-frequency or ultra-low-frequency sound waves, that is, its sound insulation curve will not start from 0, and it has excellent sound insulation performance for low-frequency sound waves.

[0063] and It is an indicator for evaluating the degree of impedance mismatch in sound insulation unit materials. If the material impedance is matched, then... The greater the degree of impedance mismatch in the materials, the... and The larger it is, as can be seen from the formula above. The larger the value, the greater the impedance difference, and the better the sound insulation effect.

[0064] In this embodiment, the sound insulation unit 10 adopts a structure in which porous material plates 101 and perforated plates 102 are arranged alternately. The perforated plate 102 has a first through-hole 1021, forming a structure with abrupt changes in area. When sound waves are transmitted to the perforated plate, they do not pass through the surrounding solid parts, but rather pass primarily through the first through-hole 1021. Compared to a solid plate without through-holes, the sound wave transmission area abruptly changes from the entire solid plate to a small hole – the first through-hole. This abrupt change in transmission area leads to a change in impedance. Due to the sudden reduction in transmission area, the impedance increases significantly, thereby affecting the overall impedance. The value can be increased, the energy transmittance is reduced, and thus the sound insulation performance of the sound insulation unit is better improved.

[0065] Furthermore, the porous material plate 101, being a plate with numerous micropores, can also increase impedance and reduce energy transmittance. Moreover, by adjusting the porosity of the porous material plate 101, the impedance of the plate can be adjusted. "Porosity" refers to the proportion of the volume of all pores in the porous material plate to the total volume of the plate; the smaller the porosity, the greater the flow resistance, and thus the greater the impedance. Figure 4 As shown, Figure 4 The image shows the sound insulation properties of porous material boards with different board densities. The horizontal axis represents the sound wave frequency, and the vertical axis represents the sound insulation. The higher the board density, the lower the porosity. Figure 4 It can be seen that a standard 9mm thick board, compared to a board of the same thickness but with double the density, has significantly reduced sound insulation. The standard board's sound insulation is approximately 5dB, while by increasing the board density, due to the significant increase in impedance, its sound insulation can reach approximately 11.5dB. Meanwhile, from... Figure 4 As can be seen from this, even in very low frequency ranges (below 50 Hz), the sound insulation of the porous material board is not zero, and it can achieve low frequency sound insulation. At the same time, due to the small thickness of 9mm, the sound insulation curves of the two boards are relatively flat and less affected by frequency changes.

[0066] In addition, such as Figure 5 As shown, Figure 5 The sound insulation performance of porous material panels of different thicknesses is shown. Figure 5 It is known that increasing the thickness of the porous material board can also increase the sound insulation. In the low-frequency range, when the thickness of the porous material board increases from 9mm to 45mm (a 5-fold increase), the sound insulation increases from 5dB to 15dB. Figure 5 It can be seen that the greater the thickness, the less flat the sound insulation curve becomes as the frequency increases.

[0067] In the sound insulation unit 10 of this embodiment, one of any two adjacent plates is a porous material plate 101 and the other is a perforated plate 102, which ensures that the porous material plate 101 and the perforated plate 102 are arranged alternately. This structure combining the porous material plate 101 and the perforated plate 102 can greatly improve the low-frequency sound insulation effect compared to setting only a porous material plate.

[0068] For example, the porous material plate 101 is made of polyester fiber, specifically PET (Polyethylene terephthalate) plate, such as... Figure 6 As shown, Figure 6The diagram shows the sound insulation curves of a traditional partition wall structure following the law of mass (without perforated panels), a partition wall structure using only PET panels (a porous material panel) (the curve representing the "PET panel" in the diagram), and the sound insulation unit in this embodiment (the curve representing the "PET panel + perforated panel" in the diagram). Figure 6 The horizontal axis represents the sound wave frequency, and the vertical axis represents the sound insulation. The thickness of the partition wall structure using only PET board (porous material board) is 20mm. In this embodiment, the perforation rate of the perforated board in the sound insulation unit (the curve where "PET board + perforated board" is located in the figure) is 9%. The material of the perforated board is copper. It adopts a 5-layer sandwich form of PET board-perforated board-PET board-perforated board-PET board. The thickness of each layer is 4mm. The length and width of the sound insulation unit are 100mm*100mm.

[0069] Depend on Figure 6 It can be seen that the sound insulation curve of the partition wall structure using only PET board (porous material board) is relatively stable, almost a straight line. However, in this embodiment, the sound insulation curve of the sound insulation unit—"PET board + perforated board"—increases rapidly after the addition of the perforated board, reaching a stable state at around 20Hz, with a sound insulation of 20dB. In contrast, the traditional partition wall structure that satisfies the mass law has a sound insulation of 0dB, and its sound insulation effect is not as good as that of the PET board alone in the low frequency range below 5 Hz, and not as good as that of the "PET board + perforated board" in the low frequency range below 15Hz.

[0070] In summary, the sound insulation unit structure in this embodiment can greatly improve the low-frequency sound insulation effect compared to simply setting a porous material board and a traditional partition wall structure.

[0071] In addition, such as Figure 7 As shown, if the frequency band is widened to 250Hz, it can be seen that around 230Hz, the traditional partition wall structure, which follows the mass law, will produce resonance. Due to the existence of this resonance, its overall sound insulation is greatly reduced. However, by using "PET board" or the "PET board + perforated board" structure in the sound insulation unit of this embodiment, this problem can be avoided, and a good sound insulation effect can be maintained over a very wide frequency band. In particular, the structure of the sound insulation unit in this embodiment has a large sound insulation, effectively ensuring low-frequency broadband sound insulation, and can also maintain a good sound insulation effect even for mid-to-high frequency sound waves.

[0072] In some embodiments, each sound insulation unit 10 may have only one first through hole 1021 in the perforated plate 102, or it may have multiple first through holes 1021.

[0073] In some schemes, the ratio of the total area of ​​all first through holes 1021 in the perforated plate 102 to the area of ​​the perforated plate 102 is the perforation rate, which is denoted as S.

[0074] For example, the perforated plate 102 is a rectangular plate with a length and width of 50mm each, and its area is 50*50=2500. The perforated plate 102 has only one circular first through hole 1021 with a radius of 2mm and an area of ​​4π. Then, the perforation rate S of the perforated plate is: S=4π / 2500.

[0075] In some implementations, the perforation rate S of the perforated plate 102 satisfies: 0.001≤S≤0.5, so as to ensure that the sound insulation unit has a good low-frequency sound insulation effect;

[0076] Furthermore, the perforation rate S satisfies: 0.001≤S≤0.36, to ensure that the sound insulation unit has a good low-frequency sound insulation effect.

[0077] The perforation rate of the perforated panel 102 has a significant impact on the sound insulation effect of the sound insulation unit. If the perforation rate S is less than 0.001, the perforated panel will be close to the properties of a solid panel, which will reduce the low-frequency sound insulation effect. It should not be too large either, with 0.5 being the best choice and preferably not exceeding 0.36.

[0078] Generally speaking, the impedance of a perforated plate is inversely proportional to its perforation rate; the smaller the perforation rate, the greater the impedance, and the two are essentially linearly related. Therefore, within a certain range, a smaller perforation rate is better. However, if the perforation rate is too small, it will hinder the propagation of sound waves too much, causing the result to tend towards the mass law and failing to achieve a good low-frequency sound insulation effect. The perforation rate selection range mentioned above can better meet the requirements.

[0079] For example, PET polyester fiber board (density 200kg / m³) is selected. 3 Porosity 0.97, flow resistance 74000 Pa·s / m², thermal characteristic length m, viscous characteristic length The perforated plate is made of copper (density 8900 kg / m³), with each layer 2mm thick and measuring 50mm x 50mm. 3 The sound insulation unit in this example uses a multi-layer structure of alternating polyester fiberboard and perforated panels, with a Young's modulus of 110 GPa and a Poisson's ratio of 0.35. Each layer is 2 mm thick and measures 50 mm x 50 mm. The sound insulation performance varies depending on the perforation rate of the perforated panels used. (The text also mentions a perforated panel with a perforation rate of 110 GPa and a Poisson's ratio of 0.35, but this is not directly related to the sound insulation unit description.) Figure 8 In the figure, the horizontal axis represents the sound wave frequency, and the vertical axis represents the sound insulation. Figure 8 The curve containing "polyester fiber board + perforated board" corresponds to a sound insulation unit composed of alternating arrangement of polyester fiber board and perforated board, while the curve containing "polyester fiber board" refers to a sound insulation structure composed of only polyester fiber board.

[0080] Depend on Figure 8 It can be seen that the sound insulation of the sound insulation unit using perforated panels with different perforation rates is as follows: the smaller the perforation rate, the greater the sound insulation, and the sound insulation curve is also very stable. The sound insulation does not start from 0 dB, and it also has a good sound insulation effect in the low frequency range.

[0081] in addition, Figure 9 This describes the sound insulation performance when perforated panels with the same perforation rate are used, but the total thickness of the sound insulation units differs; among them, Figure 9 The perforation rate of the perforated panels in the different sound insulation units is 9%, and the total thickness of the different sound insulation units is 20mm, 40mm, and 60mm, respectively. Figure 9 It can be seen that the greater the thickness of the sound insulation unit, the greater the sound insulation amount, and the better the sound insulation effect.

[0082] In some embodiments, the porosity of the porous material plate 101 is 0.6 to 0.99 to improve the sound insulation effect.

[0083] By adjusting the porosity of the porous material plate 101, the impedance of the plate can be adjusted. The smaller the porosity, the greater the flow resistance, which in turn increases the impedance, thus affecting the overall impedance. The value of porosity can be increased, reducing energy transmittance and thus improving the sound insulation performance of the sound insulation unit. However, the porosity should not be too small. On the one hand, it is more difficult to prepare porous material boards with too small a porosity. On the other hand, the properties of porous material boards with too small a porosity are close to those of solid boards, causing the results to tend to follow the mass law and thus failing to achieve a good low-frequency sound insulation effect. The porosity selection range mentioned above can better meet the requirements.

[0084] In the specific preparation process, the following methods can be used to prepare porous material plates 101 with low porosity: one is to make the material as dense and compact as possible to reduce the porosity and increase the flow resistance. For example, porous material plates can be prepared by hot pressing PET material to squeeze more fibers into the same space, thereby increasing the impedance of the porous material; the other is to select finer fiber raw materials so that more fibers can be added to the space.

[0085] In some implementations, the area of ​​each first through hole 1021 is not less than π / 4 mm², that is, if the first through hole 1021 is a circular hole, its diameter is not less than 1 mm. If the area of ​​the first through hole 1021 is too small, it will hinder the propagation of sound waves too much and reduce the low-frequency sound insulation effect.

[0086] It is understood that the first through hole 1021 in this embodiment can be a round hole, or it can be a hole, slit, etc. of other shapes.

[0087] In some embodiments, the acoustic impedance of the perforated plate 102 is greater than that of air, allowing for the selection of a more rigid plate material to facilitate the shaping and installation of the overall structure. Furthermore, using a rigid plate material can increase the resonant frequency, thereby maintaining good sound insulation at low frequencies.

[0088] For example, the perforated plate 102 may be made of any one of rubber, stone, plastic, wood, metal plate, fiberglass or carbon fiber.

[0089] In some embodiments, each sound insulation unit 10 includes multiple perforated panels 102, and all the perforated panels in each sound insulation unit 10 have the same perforation rate.

[0090] Alternatively, at least two perforated plates in each sound insulation unit 10 may have different perforation rates. For example, the sound insulation unit 10 may have perforated plates with different perforation rates; or the perforation rate of each perforated plate in the sound insulation unit 10 may increase or decrease along the first direction to form a gradient perforation structure.

[0091] See Figure 10 , Figure 10 The results show the sound insulation performance when the perforation rate of each perforated panel in the sound insulation unit is the same (9% or 16%), and when the perforation rate is different (gradual perforation). Figure 10 The curve representing "polyester fiberboard + perforated board" corresponds to a sound insulation unit constructed by alternating layers of polyester fiberboard (perforated material board) and perforated boards. This sound insulation unit employs a 5-layer sandwich structure of "polyester fiberboard-perforated board-polyester fiberboard-perforated board-polyester fiberboard" (see reference). Figure 3 The curves showing "9% perforation rate" indicate that the two perforated panels in the sound insulation unit have the same perforation rate of 9%, "16% perforation rate" indicate that the two perforated panels in the sound insulation unit have the same perforation rate of 16%, and "gradual perforation" indicate that the two perforated panels in the sound insulation unit have different perforation rates of 9% and 16%, respectively.

[0092] The "gradually perforated" sound insulation unit has different perforation rates on its inner and outer layers, resulting in different flow resistances and thus a structure with gradually varying impedance. Figure 10 It can be seen that the "gradient perforation" sound insulation structure also has good low-frequency sound insulation effect, and also has a good sound insulation effect in higher frequency bands. Its sound insulation curve is located between the curves with "9% perforation rate" and "16% perforation rate", and the trend of the curves is basically consistent with both. Therefore, the sound insulation unit using "gradient perforation" can also achieve a good sound insulation effect.

[0093] In some embodiments, each sound insulation unit 10 includes multiple layers of porous material plates 101, and all porous material plates in each sound insulation unit 10 have the same porosity.

[0094] Alternatively, at least two of the porous material panels in each sound insulation unit 10 may have different porosities. For example, the porosity of each porous material panel may increase or decrease along a first direction, or the porous material panels may have different porosities.

[0095] See Figure 11 , Figure 11 The display shows the sound insulation performance when the porosity of each porous material plate in the sound insulation unit is the same (all low flow resistance or all high flow resistance), and when the porosity is different (low flow resistance + high flow resistance). Figure 11 The sound insulation units corresponding to each curve in the figure are all composed of alternating layers of PET boards (porous material boards) and perforated boards. These sound insulation units use a 5-layer sandwich structure of "PET board-perforated board-PET board-perforated board-PET board". The perforation rate of the perforated boards is 9%. In the figure, the three PET boards in the sound insulation unit corresponding to "Scheme 1" are all low-flow-resistance PET boards with the same and relatively high porosity. In the sound insulation unit corresponding to "Scheme 2", the first and third PET boards are low-flow-resistance PET boards, and the fifth PET board is a high-flow-resistance PET board with a lower porosity than the low-flow-resistance PET board. In the sound insulation unit corresponding to "Scheme 3", the first PET board is a low-flow-resistance PET board, and the third and fifth PET boards are high-flow-resistance PET boards. In the sound insulation unit corresponding to "Scheme 4", the three PET boards are all high-flow-resistance PET boards with the same and relatively low porosity.

[0096] Depend on Figure 11 It can be seen that the sound insulation units in Schemes 2 and 3 both use PET boards (porous material boards) with different porosities. This structural form can also achieve good low-frequency sound insulation and has good sound insulation performance in higher frequency bands. The sound insulation effect of this sound insulation structure is worse than that of Scheme 1, which uses a structure with low flow resistance (high porosity) throughout, but not as good as that of Scheme 4, which uses a structure with high flow resistance (low porosity) throughout. Therefore, from Figure 11 It can also be seen that the more high flow resistance plates there are in each PET board (porous material board) in the sound insulation unit, the greater the sound insulation and the better the sound insulation effect.

[0097] In some implementations, the sound insulation structure is placed in the corresponding environmental medium. The maximum frequency of the sound wave blocked by the sound insulation structure is a first frequency fm. The transmission wavelength of the sound wave in the environmental medium at the first frequency is a first wavelength λm. The maximum size of the sound insulation unit is Lm, so Lm≤0.5λm, to ensure that there is a good sound insulation effect below the first frequency.

[0098] In the sound insulation unit 10, the sum of the thicknesses of a porous material plate 101 and a perforated plate 102 is L1. The sound insulation unit 10 is rectangular, and the length of its diagonal is L2. If L1 ≥ L2, then Lm = L1; if L2 > L1, then Lm = L2. That is, the larger of the "diagonal length L2 of the sound insulation unit" and the "sum of the thicknesses of a porous material plate and a perforated plate L1" is taken as the "maximum size Lm of the sound insulation unit".

[0099] For example, the sound insulation structure described above is used as a partition wall and is placed in the air. In this case, the "environmental medium" is air. The first wavelength λm corresponds to the wavelength of the sound wave in the air. If a good sound insulation effect is desired within the 1000Hz frequency band, then Lm≤0.5λm must be satisfied. Since the speed of sound in the air is 340 m / s, then λm=340 / 1000. Therefore, Lm≤0.5*(340 / 1000)=0.17m.

[0100] In some embodiments, the thickness of the perforated plate 102 is 1–20 mm, and the thickness of the porous material plate 101 is 1–50 mm. The thickness of each plate affects the sound insulation effect; the greater the thickness, the better the sound insulation effect. However, if the thickness is too great, the overall weight of the partition wall or the space occupied will also increase accordingly, which is not conducive to installation and use.

[0101] The perforated plate 102 in this example can be made of any one of rubber, stone, plastic, wood, metal plate, fiberglass or carbon fiber;

[0102] The porous material board 101 can be made of any one of polyester fiber, rock wool, glass fiber, basalt fiber, or foam material, or it can be made of porous material made of melamine, or porous material made of animal or plant fibers such as wool.

[0103] The sound insulation structure in this embodiment may have only one sound insulation unit 10 or multiple sound insulation units 10.

[0104] like Figure 1 As shown, when the sound insulation structure has multiple sound insulation units 10, all the sound insulation units 10 are laid out flat, and there is no gap between two adjacent sound insulation units 10. Gaps will cause serious sound leakage and reduce the sound insulation.

[0105] The specifications of each sound insulation unit 10 in the sound insulation structure can be the same or different. The sound insulation unit 10 can be rectangular, triangular, hexagonal or other shapes, which can be selected according to actual needs.

[0106] Furthermore, the porous material panels located on the same layer in the sound insulation structure are integrally formed.

[0107] The above-mentioned sound insulation structure can be manufactured using the following methods:

[0108] For example, first select a substrate and a solid plate. The substrate is made of a porous material. Divide the substrate into multiple sound insulation unit areas. Connect a solid plate to the substrate and open multiple first through holes on the solid plate to form an integral perforated plate. The projection of these first through holes on the substrate is located in the corresponding sound insulation unit area. Each sound insulation unit area may have one or more first through holes. The porous material area and the perforated plate area in each sound insulation unit area constitute a sound insulation unit. It can be understood that the sound insulation structure formed by the above method is a two-layer structure. If more layers are required, simply continue to stack the substrate and solid plate and open the first through holes on the solid plate. When stacking, it is necessary to ensure that the substrate and solid plate are arranged alternately.

[0109] Compared to the above preparation methods, in some other preparation methods, after selecting a substrate, multiple horizontal and vertical strips can be connected on the substrate to form a grid structure layer. The grid holes inside each grid structure serve as the first through holes. This grid structure layer is equivalent to an integral perforated plate. Dividing the grid structure layer into unit areas constitutes the perforated plate area within multiple sound insulation units.

[0110] In some other preparation methods, multiple sound insulation units can be spliced ​​together to form a sound insulation structure.

[0111] The sound insulation structure in this embodiment can be used directly as a wall, or it can replace the plasterboard in an existing wall, or it can be placed at a certain distance from the existing wall to work in conjunction with it. All of these applications can improve the sound insulation effect of the corresponding space, especially for low-frequency noise, where the sound insulation effect is significant. The sound insulation structure in this embodiment can also be used as a sound barrier in other scenarios.

[0112] Example 2

[0113] This embodiment discloses a sound insulation structure, which includes at least one sound insulation unit 10. The main difference between this embodiment and Embodiment 1 is that a first filler is filled in the first through hole 1021 of the perforated plate 102, and the first filler is a porous material.

[0114] In this embodiment, each sound insulation unit includes multiple layers of plates connected sequentially along a first direction. In any two adjacent layers, one is a porous material plate 101 and the other is a perforated plate 102. The perforated plate 102 is provided with at least one first through hole 1021 for sound waves to pass through. That is, the porous material plate 101 and the perforated plate 102 in the sound insulation unit are arranged alternately.

[0115] After setting the first through hole 1021 on the perforated plate 102, it is necessary to fill the first through hole 1021 with porous material. This method can further enhance the sound insulation effect of the sound insulation unit 10.

[0116] See Figure 12 , Figure 12 This shows a comparison of the sound insulation performance of a sound insulation unit filled with porous polyester fiber in the first through-hole of a perforated panel with other sound insulation structures. Figure 12 The sound insulation units corresponding to the curves for "polyester fiber board + perforated board" are all sound insulation units composed of alternating arrangements of polyester fiber board (porous material board) and perforated board. The perforation rate of the perforated board is 9%. One solution is to fill the first through hole of the perforated board with polyester fiber, while the other solution does not require filling the first through hole with material. Figure 12 The sound insulation structure corresponding to the curve of "polyester fiber board" does not have perforated panels;

[0117] Depend on Figure 12 It can be seen that if porous material - polyester fiber - is filled into the perforated plate of the sound insulation unit, its impedance will be further increased and the sound insulation will be significantly increased compared with the structure without filling, which can effectively improve the sound insulation effect; in addition, compared with the sound insulation structure that does not have a perforated plate and only uses polyester fiber board, its sound insulation is also greatly improved.

[0118] The sound insulation unit of this embodiment can provide good sound insulation for low-frequency sound waves within 500Hz (including extremely low-frequency bands below 20Hz), as well as mid-to-high frequency bands from 500Hz to 3kHz, and even higher frequency bands.

[0119] All the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of the present invention. That is, any number of embodiments can be combined to meet the needs of different application scenarios. All of these are within the protection scope of this application and will not be described in detail here.

[0120] It should be noted that the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A sound insulation structure, characterized in that: It includes at least one sound insulation unit, each of the sound insulation units including multiple layers of plates connected sequentially along a first direction, wherein one of any two adjacent layers of plates is a porous material plate and the other is a perforated plate, and the perforated plate is provided with at least one first through hole for sound waves to pass through. All the sound insulation units are laid out in a flat manner, with no gaps between adjacent sound insulation units; The sound insulation structure is placed in a corresponding environmental medium. The maximum frequency of the sound wave blocked by the sound insulation structure is a first frequency fm. The transmission wavelength of the sound wave at the first frequency in the environmental medium is a first wavelength λm. The maximum size of the sound insulation unit is Lm, then Lm≤0.5λm; In the sound insulation unit, the sum of the thicknesses of a porous material plate and a perforated plate is L1. The sound insulation unit is rectangular, and the length of its diagonal is L2. If L1 ≥ L2, then Lm = L1; if L2 > L1, then Lm = L2.

2. The sound insulation structure according to claim 1, characterized in that: The ratio of the total area of ​​all first through holes in the perforated plate to the area of ​​the perforated plate is called the perforation rate, which is denoted as S. Then, 0.001≤S≤0.

5.

3. The sound insulation structure according to claim 2, characterized in that: The perforation rate is denoted as S, and then 0.09≤S≤0.

36.

4. The sound insulation structure according to claim 1, characterized in that: The porosity of the porous material plate is 0.6 to 0.

99.

5. The sound insulation structure according to claim 1, characterized in that: The area of ​​each of the first through holes is not less than π / 4 mm².

6. The sound insulation structure according to claim 1, characterized in that: The acoustic impedance of the perforated plate is greater than that of air.

7. The sound insulation structure according to claim 1, characterized in that: Each sound insulation unit comprises multiple layers of perforated panels, wherein all the perforated panels in each sound insulation unit have the same perforation rate; or, at least two of the perforated panels in each sound insulation unit have different perforation rates.

8. The sound insulation structure according to claim 1, characterized in that: Each sound insulation unit comprises multiple layers of porous material panels, wherein all the porous material panels in each sound insulation unit have the same porosity; or, at least two of the porous material panels in each sound insulation unit have different porosities.

9. The sound insulation structure according to claim 1, characterized in that: The thickness of the perforated plate is 1-20 mm, and the thickness of the porous material plate is 1-50 mm.

10. The sound insulation structure according to claim 1, characterized in that: The first through hole is filled with a first filler, which is a porous material.

11. The sound insulation structure according to claim 1, characterized in that: The perforated plate is made of any one of rubber, stone, plastic, wood, metal plate, fiberglass or carbon fiber; the porous material plate is made of any one of polyester fiber, rock wool, glass fiber, basalt fiber or foam material.

12. The sound insulation structure according to claim 1, characterized in that: The sound insulation unit has a high energy transmittance of sound waves. Satisfy the following formula: ； in, The wavenumber of the sound waves in the sound insulation unit. The angular frequency of the sound wave. The velocity of sound in the sound insulation unit. This represents the sound loss of the sound insulation unit during sound wave propagation. This represents the thickness of the sound insulation unit; , , For the density of the environmental medium, The speed of sound in the ambient medium. This is the equivalent acoustic density of the sound insulation unit.

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