Acoustic metamaterial composite sound absorption structure

Abstract

The invention relates to the technical field of noise control, in particular to an acoustic metamaterial composite sound absorption structure which comprises a sound absorption box, a separation frame and a mass block, an opening is formed in the top of the sound absorption box, the separation frame is fixed in the sound absorption box, a sound absorption film is arranged between the exterior of the upper portion of the separation frame and the upper portion of the side wall of the sound absorption box, and the sound absorption film is arranged in the upper portion of the separation frame. The multiple mass blocks are fixed to the upper surface of the sound absorption film, and multiple rows of first sound absorption holes are formed in the bottom wall of the sound absorption box. The problem that a traditional perforated plate resonance absorption structure is poor in sound absorption effect is solved.

Description

Technical Field

[0001] This invention relates to the field of noise control technology, specifically to an acoustic metamaterial composite sound-absorbing structure. Background Technology

[0002] Acoustic metamaterials are artificial composite structures or composite materials with extraordinary physical properties. By making special designs on key physical scales, they can obtain unusual acoustic properties not found in natural materials, such as sound wave reflection, absorption, filtering, wave guiding, focusing, superlensing, and stealth, giving them broad research and application prospects in fields such as sound absorption and noise reduction.

[0003] Traditional perforated plate resonant absorption structures have a closed cavity behind each hole in the perforated plate. When the frequency of the incident wave matches the resonant frequency of the system, resonance occurs. At this point, the air in the holes of the perforated plate vibrates back and forth, reaching its maximum amplitude, and friction and damping are also at their maximum. Sound energy is converted into heat energy due to viscous loss, meaning sound energy dissipation reaches its maximum. This is the advantage of perforated plate resonant absorption structures. However, this structure also has its inherent disadvantages. Its main disadvantage is its strong frequency selectivity, meaning its sound absorption bandwidth is narrow. It only has good sound absorption performance near the resonant frequency, and its sound absorption effect deteriorates significantly when it deviates from the resonant frequency. Summary of the Invention

[0004] This invention proposes an acoustic metamaterial composite sound-absorbing structure, which solves the problem of poor sound absorption effect of traditional perforated plate resonant absorption structures.

[0005] To achieve the above objectives, this invention proposes an acoustic metamaterial composite sound-absorbing structure, comprising a sound-absorbing box, a partition frame, and a mass block; The sound-absorbing box has an opening at the top, the partition frame is fixed inside the sound-absorbing box, a sound-absorbing membrane is provided between the upper outer part of the partition frame and the upper part of the side wall of the sound-absorbing box, and a sound-absorbing membrane is provided inside the upper part of the partition frame. The mass blocks are provided in multiple quantities, and the multiple mass blocks are fixed to the upper surface of the sound-absorbing film; The bottom wall of the sound-absorbing box has multiple rows of sound-absorbing holes.

[0006] Preferably, the row spacing D1 of the multiple rows of sound-absorbing holes near the side wall of the sound-absorbing box is greater than the row spacing D2 of the multiple rows of air inlets located in the central region of the sound-absorbing box, and the partition frame is located above the multiple rows of air inlets in the central region of the sound-absorbing box.

[0007] Preferably, the sound-absorbing box is provided with a partition, and the partition has a plurality of sound-absorbing holes, the axes of which coincide.

[0008] Preferably, the diameter of the first sound-absorbing hole is larger than the diameter of the second sound-absorbing hole.

[0009] Preferably, a plurality of vertical sound-passing tubes are fixed between the partition and the bottom wall of the sound-absorbing box, and the axis of the sound-passing tubes coincides with the axis of the first sound-absorbing hole and the second sound-absorbing hole.

[0010] Preferably, the sound-passing tube is a tapered tube with the small end facing upwards.

[0011] Preferably, the sound-absorbing box has an annular sound-passing plate inside its side wall, and a gap is left between the inner edge of the sound-passing plate and the side wall of the partition frame. The outer side wall of the partition frame is provided with an annular sound-passing plate II, and a gap is left between the outer edge of the sound-passing plate II and the side wall of the sound-absorbing box. Both the first sound-passing plate and the second sound-passing plate are located between the partition and the sound-absorbing film.

[0012] Preferably, the partition frame is provided with two sound-passing plates, which are arranged vertically and fixed to the left and right side walls of the partition frame respectively.

[0013] The present invention has the following beneficial effects: 1. The sound-passing plate one and the sound-passing plate two separate the space between the partition and the sound-absorbing film, forming a sound-passing channel. This not only extends the propagation path of the sound wave, but also increases the number of sound wave reflections, allowing more sound waves to cancel each other out, thereby greatly improving the noise reduction efficiency. 2. The two sound-passing panels also divide the space within the partition frame, forming a sound-passing channel, which also improves the noise reduction efficiency; 3. Since the row spacing D1 of the multiple rows of sound-absorbing holes near the side wall of the sound-absorbing box is greater than the row spacing D2 of the multiple rows of air inlets located in the central area of ​​the sound-absorbing box, and multiple different row spacings of sound-absorbing holes can be set, the sound-absorbing box can absorb noise of different frequency bands, which greatly improves the noise reduction efficiency.

[0014] 4. The mass block forms a local resonant unit through coupling with an elastic matrix such as a sound-absorbing film. Under dynamic load, the detuning of the motion between the mass block and the matrix can absorb sound wave energy, generate a low-frequency bandgap, and achieve sound wave attenuation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the acoustic metamaterial composite sound-absorbing structure described in this invention; Figure 2 This is a schematic diagram of the bottom structure of the sound-absorbing box in the acoustic metamaterial composite sound-absorbing structure described in this invention; Figure 3This is a schematic diagram of the internal structure of the sound-absorbing box in the acoustic metamaterial composite sound-absorbing structure described in this invention; Figure 4 This is a front cross-sectional view of the sound-absorbing box in the acoustic metamaterial composite sound-absorbing structure described in this invention; Figure 5 This is a schematic diagram showing the distribution of the second sound-absorbing hole in the acoustic metamaterial composite sound-absorbing structure described in this invention.

[0016] In the diagram: 1. Sound-absorbing box; 11. Sound-absorbing hole one; 12. Partition; 121. Sound-absorbing hole two; 13. Sound-passing pipe; 14. Sound-passing plate one; 15. Sound-passing plate two; 2. Sound-absorbing membrane; 3. Separator frame; 31. Sound-passing plate three; 4. Mass block. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0018] This invention proposes an acoustic metamaterial composite sound-absorbing structure, such as... Figure 1 and Figure 2 As shown, the device includes a sound-absorbing box 1, a partition frame 3, and mass blocks 4. The top of the sound-absorbing box 1 is open. The partition frame 3 is fixed inside the sound-absorbing box 1. A sound-absorbing membrane 2 is provided between the upper outer part of the partition frame 3 and the upper part of the side wall of the sound-absorbing box 1. A sound-absorbing membrane 2 is provided inside the upper part of the partition frame 3. Multiple mass blocks 4 are provided and multiple mass blocks 4 are fixed on the upper surface of the sound-absorbing membrane 2. Multiple rows of sound-absorbing holes 11 are opened on the bottom wall of the sound-absorbing box 1.

[0019] The sound-absorbing membrane 2 is made of materials such as polyurethane, silicate fiber, and polyester fiber.

[0020] Mass block 4 forms a local resonant unit through coupling with elastic substrates such as sound-absorbing film 2. Under dynamic load, the motion detuning between mass block 4 and the substrate (such as the reverse vibration of lead block and epoxy resin substrate) can absorb sound wave energy, generate a low-frequency bandgap, and achieve sound wave attenuation.

[0021] like Figure 4 and Figure 5 As shown, the row spacing D1 of the multiple rows of sound-absorbing holes 11 near the side wall of the sound-absorbing box 1 is greater than the row spacing D2 of the multiple rows of air inlets located in the central area of ​​the sound-absorbing box 1, and the partition frame 3 is located above the multiple rows of air inlets in the central area of ​​the sound-absorbing box 1.

[0022] like Figure 3 and Figure 4 As shown, the sound-absorbing box 1 is provided with a partition 12, and multiple sound-absorbing holes 121 are provided on the partition 12. The axes of the sound-absorbing holes 11 and 121 coincide.

[0023] like Figure 4 and Figure 5As shown, the aperture of sound-absorbing hole 11 is larger than the aperture of sound-absorbing hole 121.

[0024] like Figure 3 As shown, multiple vertical sound-passing pipes 13 are fixed between the partition 12 and the bottom wall of the sound-absorbing box 1. The axis of the sound-passing pipe 13 coincides with the axis of the first sound-absorbing hole 11 and the second sound-absorbing hole 121.

[0025] like Figure 3 and Figure 4 As shown, the sound tube 13 is a tapered tube.

[0026] like Figure 3 and Figure 4 As shown, the small end of the sound tube 13 is facing upwards.

[0027] like Figure 4 and Figure 5 As shown, since the row spacing D1 of the multiple rows of sound-absorbing holes 11 near the side wall of the sound-absorbing box 1 is greater than the row spacing D2 of the multiple rows of air inlets 1 located in the central area of ​​the sound-absorbing box 1, and multiple different row spacings of sound-absorbing holes 11 and sound-absorbing holes 121 can be set, the sound-absorbing box 1 can absorb noise of different frequency bands, which greatly improves the noise reduction efficiency.

[0028] An expansion chamber is formed between the partition 12 and the sound-absorbing film 2. After the sound waves enter the chamber, they are reflected. Since the reflected sound waves change their propagation direction, some of the sound waves will cancel each other out, thus achieving a noise reduction effect.

[0029] The sound-passing tube 13 is a tapered tube with the small end facing upward and the large end facing downward. In this way, sound waves can more easily enter the sound-absorbing box 1 from the sound-absorbing hole 11 and enter the space between the partition 12 and the sound-absorbing film 2 through the sound-passing tube 13.

[0030] like Figure 3 As shown, an annular sound-passing plate 14 is provided inside the side wall of the sound-absorbing box 1, and a gap is left between the inner edge of the sound-passing plate 14 and the side wall of the partition frame 3. An annular sound-passing plate 15 is provided on the outside of the side wall of the partition frame 3, and a gap is left between the outer edge of the sound-passing plate 15 and the side wall of the sound-absorbing box 1. Both the first sound-passing plate 14 and the second sound-passing plate 15 are located between the partition plate 12 and the sound-absorbing film 2.

[0031] like Figure 3 As shown, the partition frame 3 is provided with two sound-passing plates 31, which are arranged vertically and fixed to the left and right side walls of the partition frame 3 respectively.

[0032] The sound-passing plate 14 and the sound-passing plate 2 separate the space between the partition 12 and the sound-absorbing film 2, forming a sound-passing channel. This not only extends the propagation path of the sound wave, but also increases the number of sound wave reflections, allowing more sound waves to cancel each other out, thereby greatly improving the noise reduction efficiency. The two sound-passing plates 31 also divide the space within the partition frame 3, forming a sound-passing channel, which also improves the noise reduction efficiency.

[0033] Using this invention, sound waves enter the expansion cavity formed by the partition 12 and the sound-absorbing film 2 through the sound-absorbing hole 11, the sound-passing pipe 13 and the sound-absorbing hole 121. After being reflected by the sound-passing plate 14, the sound-passing plate 15 and the side wall of the sound-absorbing box 1, as well as by the two sound-passing plates 31 and the side wall of the partition frame 3, the sound waves are weakened. Combined with the interaction between the sound-absorbing film 2 and the mass block 4, the noise reduction efficiency is improved.

[0034] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An acoustic metamaterial composite sound-absorbing structure, characterized in that, It includes a sound-absorbing box (1), a partition frame (3), and a mass block (4); The top opening of the sound-absorbing box (1) is provided, the partition frame (3) is fixed inside the sound-absorbing box (1), and a sound-absorbing film (2) is provided between the upper outer part of the partition frame (3) and the upper part of the side wall of the sound-absorbing box (1). A sound-absorbing film (2) is provided inside the upper part of the partition frame (3). Multiple mass blocks (4) are provided, and multiple mass blocks (4) are fixed on the upper surface of the sound-absorbing film (2); The bottom wall of the sound-absorbing box (1) has multiple rows of sound-absorbing holes (11).

2. The acoustic metamaterial composite sound-absorbing structure according to claim 1, characterized in that, The row spacing D1 of the multiple rows of sound-absorbing holes (11) near the side wall of the sound-absorbing box (1) is greater than the row spacing D2 of the multiple rows of air inlets located in the central area of ​​the sound-absorbing box (1). The partition frame (3) is located above the multiple rows of air inlets in the central area of ​​the sound-absorbing box (1).

3. The acoustic metamaterial composite sound-absorbing structure according to claim 1, characterized in that, The sound-absorbing box (1) is provided with a partition (12), and a plurality of sound-absorbing holes (121) are provided on the partition (12). The axes of the sound-absorbing holes (11) and the sound-absorbing holes (121) coincide.

4. The acoustic metamaterial composite sound-absorbing structure according to claim 3, characterized in that, The diameter of the first sound-absorbing hole (11) is larger than the diameter of the second sound-absorbing hole (121).

5. The acoustic metamaterial composite sound-absorbing structure according to claim 4, characterized in that, Multiple vertical sound-passing pipes (13) are fixed between the partition (12) and the bottom wall of the sound-absorbing box (1), and the axis of the sound-passing pipe (13) coincides with the axis of the first sound-absorbing hole (11) and the second sound-absorbing hole (121).

6. The acoustic metamaterial composite sound-absorbing structure according to claim 5, characterized in that, The sound-passing tube (13) is a tapered tube with its small end facing upwards.

7. The acoustic metamaterial composite sound-absorbing structure according to claim 3, characterized in that, The sound-absorbing box (1) has an annular sound-passing plate (14) inside its side wall, and there is a gap between the inner edge of the sound-passing plate (14) and the side wall of the partition frame (3). The side wall of the partition frame (3) is provided with an annular sound-passing plate two (15), and there is a gap between the outer edge of the sound-passing plate two (15) and the side wall of the sound-absorbing box (1). Both the first sound-passing plate (14) and the second sound-passing plate (15) are located between the partition plate (12) and the sound-absorbing film (2).

8. The acoustic metamaterial composite sound-absorbing structure according to claim 3, characterized in that, The partition frame (3) is provided with two sound-passing plates (31), which are arranged vertically and are respectively fixed to the left and right side walls of the partition frame (3).

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