Movable membrane-shaped metamaterial acoustic barrier and method of installation

Abstract

The application discloses a movable membrane-shaped metamaterial sound barrier, which comprises a thin film noise reduction unit and a structure fixing unit for arranging and fixing the thin film noise reduction unit, wherein the thin film noise reduction unit comprises a microporous membrane, a first cavity, a first sound insulation layer, a second cavity and a second sound insulation layer arranged along the sound wave propagation direction, and the microporous membrane is provided with a plurality of micropores for absorbing sound waves; when sound waves enter the first cavity through the microporous membrane, the micropores and the first cavity are used for preliminary noise reduction to reduce reflected sound generated by the sound waves; the sound energy of the transmitted sound waves is reduced through the first sound insulation layer and the second sound insulation layer; and the sound energy of the transmitted sound waves is further reduced through the second cavity. The application further provides an installation method. The sound barrier provided by the application is convenient to disassemble and assemble and has the effects of sound insulation and sound absorption, so that the noise pollution of construction equipment in a construction site can be effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of noise control technology, and in particular relates to a movable membrane metamaterial sound barrier and its installation method. Background Technology

[0002] Construction sites are characterized by complex noise sources, high sound levels, and high mobility. Existing noise control measures for construction sites mainly employ barrier measures such as retaining walls and construction fences, which play a certain role in controlling noise at construction sites. However, these barriers are heavy, inconvenient to move, and the disassembly, assembly, and transportation processes are quite cumbersome. Furthermore, the barriers themselves have poor sound insulation performance and no sound absorption function.

[0003] Patent document CN218292362U discloses a sliding rail movable sound barrier that uses low-density aluminum foam to achieve sound absorption and noise reduction. The bottom of the sound barrier is equipped with omnidirectional ball bearings for easy movement. However, this patented sound barrier has the following drawbacks: First, while the omnidirectional ball bearings at the bottom enable movement, they also create a gap between the bottom of the sound barrier and the ground, resulting in significant sound leakage and poor overall sound insulation performance. Second, the sound barrier has a complex structure, making it inconvenient to install and disassemble, and its mobility is poor on construction sites with uneven terrain.

[0004] Patent document CN114046085 A discloses a movable inflatable sound barrier that uses PVC mesh and Oxford cloth inflatable bladders to isolate noise sources, reducing the propagation distance and intensity of noise. However, this device only isolates the noise source and has no sound absorption function. Furthermore, the presence of rollers at the bottom of the device indicates the existence of gaps, which could lead to sound leakage. Summary of the Invention

[0005] The purpose of this invention is to provide a movable membrane metamaterial sound barrier and its installation method. This sound barrier is easy to assemble and disassemble and has both sound insulation and sound absorption functions, thereby effectively reducing noise pollution from construction equipment at building construction sites.

[0006] To achieve the first objective of this invention, a movable membrane metamaterial sound barrier is provided, comprising a thin-film noise reduction unit and a structural fixing unit for arranging and fixing the thin-film noise reduction unit. The thin-film noise reduction unit includes a microporous membrane arranged along the sound wave transmission direction, a first cavity, a first sound insulation layer, a second cavity, and a second sound insulation layer. The surface of the microporous membrane is provided with a plurality of micropores for absorbing sound waves.

[0007] When sound waves enter the first cavity through the microporous membrane, the micropores and the first cavity are used for preliminary noise reduction to reduce the reflected sound generated by the sound waves. The sound energy of the transmitted sound waves is reduced by the first sound insulation layer and the second sound insulation layer. At the same time, the sound energy of the transmitted sound waves is further reduced by the second cavity.

[0008] Specifically, the first sound insulation layer is equipped with a valve for inflating or deflating the second cavity.

[0009] Specifically, the structural fixing unit includes fixing buckles for fixing the microporous membrane to the first sound insulation layer and fixing ropes for fixing the bottom and top of the film noise reduction unit.

[0010] Specifically, the fixing buckle is located on the surface of the first sound insulation layer, and the microporous membrane is covered on the outside of the first sound insulation layer by the fixing buckle.

[0011] Specifically, the top of the thin-film noise reduction unit is provided with a ribbon for reducing diffraction sound energy and a hanging ring for moving the thin-film noise reduction unit.

[0012] Specifically, the surfaces of the microporous membrane, the first sound insulation layer, and the second sound insulation layer are all provided with mass blocks.

[0013] Preferably, the mass block is a magnetic mass block, and the adjacent magnetic poles of two directly opposite magnetic mass blocks have the same polarity, thereby forming a negative mass density and negative stiffness to improve the sound absorption performance.

[0014] Specifically, a gas injection process is performed in the second cavity, and the injected gas is one or more of helium, nitrogen, or other stable gases.

[0015] Specifically, the first and second sound insulation layers are made of gradient acoustic metamaterials or membrane-shaped sound insulation materials.

[0016] To achieve the second objective of this invention, an installation method is also provided for arranging the aforementioned movable membrane metamaterial sound barrier, comprising the following steps:

[0017] The installation steps are as follows: First, lay the first and second sound insulation layers flat and inflate them. Then, fix the microporous membrane and the first sound insulation layer with the fixing buckles to assemble the thin film noise reduction unit. Finally, fix the bottom and top of the thin film noise reduction unit.

[0018] The dismantling steps are as follows: first, remove the fixing devices at the bottom and top of the film noise reduction unit, then lay the film noise reduction unit flat, remove the microporous membrane, and finally release the gas.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] This invention, while ensuring light weight, easy assembly and disassembly, and easy relocation, combines lightweight, flexible acoustic metamaterials with various auxiliary components to achieve efficient sound insulation and sound absorption of the sound barrier. The designed lightweight sound barrier has excellent sound insulation and sound absorption performance. Attached Figure Description

[0021] Figure 1 This is a longitudinal cross-sectional schematic diagram of the movable membrane metamaterial sound barrier provided in this embodiment;

[0022] Figure 2 This is a schematic longitudinal cross-sectional view of the microporous membrane provided in this embodiment;

[0023] Figure 3 This is a longitudinal cross-sectional schematic diagram of the first and second sound insulation layers provided in this embodiment;

[0024] Figure 4 This is a longitudinal cross-sectional view of the mass block provided in this embodiment when it is disposed on the surface of the microporous membrane and the first sound insulation layer;

[0025] Figure 5 This is a longitudinal cross-sectional view of the mass block provided in this embodiment when it is disposed on the surfaces of the first and second sound insulation layers.

[0026] Figure 6 This is a longitudinal cross-sectional view of the movable membrane metamaterial sound barrier provided in this embodiment when it is arranged on the water injection tank.

[0027] Figure 7 This is a longitudinal cross-sectional schematic diagram of the second type of movable membrane metamaterial sound barrier provided in this embodiment;

[0028] In the diagram, 1. Hanging ring; 2. Ribbon; 3. Fixing rope; 4. Mass block; 5. Microporous membrane; 6. First cavity; 7. Fixing buckle; 8. First sound insulation layer; 9. Second cavity; 10. Second sound insulation layer; 11. Valve; 12. Water injection chamber. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] like Figures 1 to 3 As shown, a movable membrane metamaterial sound barrier includes a thin film noise reduction unit and a structural fixing unit.

[0031] The thin-film noise reduction unit includes a microporous membrane 5, a first cavity 6, a first sound insulation layer 8, a second cavity 9, and a second sound insulation layer 10; the structural fixing unit includes a fixing buckle 7 and a fixing rope 3. The first sound insulation layer 8 is provided with a valve 11 for inflating or deflating the second cavity 9. The thin-film noise reduction unit is fixed by the fixing rope 3. The fixing buckle 7 is located on the surface of the first sound insulation layer 8, and the microporous membrane 5 covers the outside of the first sound insulation layer 8 through the fixing buckle 7.

[0032] When sound waves enter the first cavity 6 through the microporous membrane 5, the micropores and the first cavity 6 are used for preliminary noise reduction to reduce the reflected sound generated by the sound waves. The sound energy of the transmitted sound waves is reduced by the first sound insulation layer 8 and the second sound insulation layer 10. At the same time, the sound energy of the transmitted sound waves is further reduced by the second cavity 9.

[0033] This embodiment also provides an installation method, including installation and removal.

[0034] The installation steps are as follows: First, lay the first sound insulation layer 8 and the second sound insulation layer 10 flat and inflate them with the valve 11. Then, fix the microporous membrane 5 and the first sound insulation layer 8 with the fixing buckle 7 to assemble the thin film noise reduction unit. Then, fix the bottom and top of the thin film noise reduction unit with the fixing rope 3.

[0035] The dismantling steps are as follows: First, remove the fixing ropes 3 at the bottom and top of the film noise reduction unit, then lay the film noise reduction unit flat, remove the microporous membrane 5, and finally open the valve 11 to release the air and retract the sound barrier.

[0036] More specifically, the materials used in this movable membrane metamaterial sound barrier are all lightweight and flexible, with low surface density, foldable, movable, easy to assemble and disassemble, and reusable.

[0037] The first cavity 6 has a depth of 5cm or other reasonable depth; the second cavity 9 has a depth of 10cm or other reasonable depth.

[0038] The microporous membrane 5, the first cavity 6, and the first sound insulation layer 8 form a micro-perforated sound-absorbing structure. When sound waves are incident on the microporous membrane 5 of the thin-film noise reduction unit, they cause the air in the micropores and the first cavity 6 to vibrate. The sound wave energy is converted into heat energy through thermal adhesion and friction, effectively absorbing the incident sound energy and reducing the reflected sound.

[0039] The first sound insulation layer 8, the air layer, and the second sound insulation layer 10 form an airbag structure, which is erected in the air using air buoyancy and rope tension, forming a sound barrier. The first sound insulation layer 8 and the second sound insulation layer 10 are preferably made of acoustically gradient materials, meaning the selected materials have a density gradient along the thickness direction, resulting in a continuous change in acoustic impedance along the thickness direction. Since sound waves are reflected when they propagate to materials with different acoustic impedances, the sound energy transmitted through the sound insulation layers is significantly reduced through continuous reflection, giving the thin sound insulation layer excellent sound insulation performance. When sound waves are incident on the first and second sound insulation layers, the two sound insulation layers effectively reduce the transmitted sound energy, giving the barrier excellent sound insulation performance. Simultaneously, the air layer between the first sound insulation layer 8 and the second sound insulation layer 10 can further increase the sound insulation.

[0040] Furthermore, mass blocks 4 can be disposed on the surfaces of the microporous membrane 5, the first sound insulation layer 8, and the second sound insulation layer 10 to effectively improve the sound absorption of the thin-film noise reduction unit. The size, quantity, and other parameters of the mass blocks 4 are adjustable. The mass blocks 4 are preferably magnetic mass blocks, and the adjacent magnetic poles of two directly opposite magnetic mass blocks have the same polarity, forming a negative mass density and negative stiffness. Through the repulsive force of the like magnetic poles, the membrane vibration is suppressed, improving the low-frequency sound absorption performance of the thin-film noise reduction unit, and breaking through the limitations of traditional mass laws in sound insulation performance.

[0041] like Figure 4 As shown, based on the movable membrane metamaterial sound barrier provided in this embodiment, only the hanging ring 1, the ribbon 2 and the mass block 4 are added. The mass block 4 is disposed on the surface of the microporous membrane 5 and the first sound insulation layer 8.

[0042] In this embodiment, mass block 4 is a magnetic mass block, and the adjacent magnetic poles of the two opposing magnetic mass blocks have the same polarity, forming a negative mass density and negative stiffness. The repulsive force of the like magnetic poles of the magnets suppresses the vibration of the thin film, improves the low-frequency sound absorption performance of the thin film noise reduction unit, and ensures that there is sufficient spacing (i.e., cavity depth) between the microporous membrane 5 and the first sound insulation layer 8.

[0043] Meanwhile, the top of the sound barrier is equipped with a hanging ring 1, which allows the sound barrier to be moved quickly by drones.

[0044] Setting a ribbon 2 at the top of the sound barrier can effectively reduce the diffracted sound energy of the sound barrier.

[0045] like Figure 5 As shown, based on the movable membrane metamaterial sound barrier provided in this embodiment, only the setting position of the mass block 4 is adjusted, that is, the mass block 4 is set on the surface of the first sound insulation layer 8 and the second sound insulation layer 10.

[0046] like Figure 6 As shown, in Figure 4 Based on the movable membrane metamaterial sound barrier shown, the bottom fixing method of the membrane noise reduction unit is adjusted. That is, the bottom of the membrane noise reduction unit is fixed to the ground by a water injection chamber 12 with a valve. The bottom of the sound barrier is in close contact with the ground, which can effectively prevent sound leakage.

[0047] like Figure 7 As shown, in Figure 1 Based on the movable membrane metamaterial sound barrier shown, only the top shape of the thin-film noise reduction unit is adjusted. That is, bending the top of the thin-film noise reduction unit towards the noise source side can effectively reduce diffracted sound energy.

[0048] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A movable membrane metamaterial sound barrier, characterized in that, The device includes a thin-film noise reduction unit and a structural fixing unit for arranging and fixing the thin-film noise reduction unit. The thin-film noise reduction unit includes a microporous membrane arranged along the sound wave transmission direction, a first cavity, a first sound insulation layer, a second cavity, and a second sound insulation layer. The surface of the microporous membrane is provided with a plurality of micropores for absorbing sound waves. The structural fixing unit includes fixing buckles for fixing the microporous membrane to the first sound insulation layer and fixing ropes for fixing the bottom and top of the film noise reduction unit; The fixing buckle is located on the surface of the first sound insulation layer, and the microporous membrane is covered on the outside of the first sound insulation layer by the fixing buckle; When sound waves enter the first cavity through the microporous membrane, the micropores and the first cavity are used for preliminary noise reduction to reduce the reflected sound generated by the sound waves. The sound energy of the transmitted sound waves is reduced by the first sound insulation layer and the second sound insulation layer. At the same time, the sound energy of the transmitted sound waves is further reduced by the second cavity. The first sound insulation layer is provided with a valve for inflating or deflating the second cavity. The surfaces of the microporous membrane, the first sound insulation layer, and the second sound insulation layer are all provided with mass blocks, which are magnetic mass blocks.

2. The movable membrane metamaterial sound barrier according to claim 1, characterized in that, The top of the thin-film noise reduction unit is equipped with a ribbon for reducing diffraction sound energy and a lifting ring for moving the thin-film noise reduction unit.

3. The movable membrane metamaterial sound barrier according to claim 1, characterized in that, The second cavity is subjected to gas injection, and the injected gas is one or more of helium, nitrogen, or other stable gases.

4. The movable membrane metamaterial sound barrier according to claim 1, characterized in that, The first and second sound insulation layers are made of gradient acoustic metamaterials or membrane sound insulation materials.

5. An installation method, characterized in that, The deployment of the movable membrane metamaterial sound barrier as described in any one of claims 1 to 4 includes the following steps: The installation steps are as follows: First, lay the first and second sound insulation layers flat and inflate them. Then, fix the microporous membrane and the first sound insulation layer with the fixing buckles to assemble the thin film noise reduction unit. Finally, fix the bottom and top of the thin film noise reduction unit. The dismantling steps are as follows: first, remove the structural fixing units at the bottom and top of the thin film noise reduction unit; then, lay the thin film noise reduction unit flat, remove the microporous membrane, and finally release the gas.

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