Impedance compound muffler

Abstract

Impedance composite muffler, including shell, both ends of the shell are provided with butt joint, the butt joint is provided with first perforated cylinder, the outer side of the first perforated cylinder is covered with first sound-absorbing layer, the outer side of the first sound-absorbing layer is covered with second perforated cylinder, the second perforated cylinder is separated from the shell by cavity, both ends of the first perforated cylinder are provided with auxiliary sound-absorbing structure. Adopt the above structure, wide frequency high efficiency noise reduction, through the aperture change reflects high frequency sound wave, realizes wide frequency coverage, forms three-dimensional sound-absorbing network simultaneously, further disperses sound wave path and enhances attenuation, ensures that sound wave must go around multilayer sound-absorbing layer, improves unit volume noise reduction efficiency, avoids that sound wave directly penetrates gap, enhances airtightness, the whole structure of device is simple, multilayer damping is set to optimize attenuation for different frequency sound waves, forces sound wave to reflect and diffract multiple times, significantly improves sound-absorbing quality.

Description

Technical Field

[0001] This utility model relates to the field of silencer technology, and in particular to impedance composite silencers. Background Technology

[0002] In industrial ventilation, air conditioning systems, and internal combustion engine exhaust treatment, mufflers are key equipment for reducing airflow noise. Existing mufflers mostly employ a single resistive or reactive structure, such as pure sound-absorbing cotton or a resonant cavity design, which generally suffers from the following shortcomings: a single resistive or reactive structure is insufficient for attenuating low-frequency noise (<500Hz), making it difficult to meet the requirements of high-noise environments; the internal airflow channel design of the muffler structure is unreasonable, easily generating secondary noise; and traditional reactive mufflers require multi-stage expansion chambers or perforated plates to achieve sound wave reflection, resulting in complex structures and large space requirements; traditional perforated plates or baffles cannot achieve multi-angle sound wave scattering, limiting the silencing frequency band.

[0003] Therefore, there is an urgent need for an impedance composite silencer that combines wideband noise reduction capability, compact structure, and the ability to suppress airflow noise. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide an impedance composite silencer that achieves wide-band and high-efficiency noise reduction. It reflects high-frequency sound waves through aperture changes to achieve wide-band coverage, while forming a three-dimensional sound-absorbing network to further disperse the sound wave path and enhance attenuation. It ensures that the sound wave must bypass multiple sound-absorbing layers, improving the noise reduction efficiency per unit volume, and avoids the sound wave from directly penetrating the gap, thus enhancing the airtightness. The overall structure of the device is simple, and the multi-layer damping setting optimizes the attenuation of sound waves of different frequencies, forcing the sound wave to reflect and diffract multiple times, significantly improving the sound absorption quality.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: an impedance composite silencer, including a shell, with interfaces at both ends of the shell, a first perforated cylinder inside the interfaces, a first sound-absorbing layer covering the outside of the first perforated cylinder, a second perforated cylinder covering the outside of the first sound-absorbing layer, a cavity between the second perforated cylinder and the shell, and auxiliary sound-absorbing structures at both ends of the first perforated cylinder.

[0006] In a preferred embodiment, the auxiliary noise reduction structure includes an interval noise reduction structure and a rotating noise reduction structure.

[0007] In a preferred embodiment, the spaced noise reduction structure includes multiple semi-circular perforated covers arranged at intervals, with a second noise reduction layer inside each semi-circular perforated cover.

[0008] In a preferred embodiment, the height of the semi-circular perforated cover exceeds the radius of the first perforated cylinder.

[0009] In a preferred embodiment, the rotating noise-absorbing structure includes multiple fan-shaped perforated covers arranged around the center of the first perforated cylinder and spaced apart, with a third noise-absorbing layer inside the fan-shaped perforated covers.

[0010] In a preferred embodiment, the height of the fan-shaped perforated cover exceeds the radius of the first perforated cylinder.

[0011] In the preferred embodiment, the rotating silencing structure completely blocks the line of sight when viewed from one side of the first perforated cylinder, making it impossible to see the other side of the first perforated cylinder directly.

[0012] The impedance composite silencer provided by this utility model, by adopting the above-described structure, has the following beneficial effects:

[0013] (1) Wideband high-efficiency noise reduction: High-frequency sound waves are reflected by aperture change to achieve wideband coverage, while forming a three-dimensional sound-absorbing network to further disperse the sound wave path and enhance attenuation;

[0014] (2) Ensure that sound waves must pass through multiple sound-absorbing layers to improve noise reduction efficiency per unit volume, prevent sound waves from directly penetrating the gap, and enhance airtightness;

[0015] (3) The device has a simple overall structure and multi-layer damping is optimized for attenuation of sound waves of different frequencies, forcing sound waves to reflect and diffract multiple times, which significantly improves the sound absorption quality. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the overall structure of this utility model.

[0019] Figure 3 This is a side view of the overall structure of the spaced noise reduction structure of this utility model.

[0020] Figure 4 This is a cross-sectional view of the overall structure of the spaced noise reduction structure of this utility model.

[0021] Figure 5 This is a side view of the overall structure of the rotating noise reduction structure of this utility model.

[0022] Figure 6 This is a cross-sectional view of the overall structure of the rotating noise reduction structure of this utility model.

[0023] In the figure: 1. Outer shell; 2. Interface; 3. First perforated cylinder; 4. First sound-absorbing layer; 5. Second perforated cylinder; 6. Cavity; 7. Interval sound-absorbing structure; 8. Rotary sound-absorbing structure; 9. Semi-circular perforated cover; 10. Second sound-absorbing layer; 11. Fan-shaped perforated cover; 12. Third sound-absorbing layer. Detailed Implementation

[0024] Example 1:

[0025] like Figure 1-6 In the middle, the impedance composite silencer includes a shell 1, the two ends of the shell 1 are provided with interface 2, the interface 2 is provided with a first perforated cylinder 3, the outside of the first perforated cylinder 3 is covered with a first sound-absorbing layer 4, the outside of the first sound-absorbing layer 4 is covered with a second perforated cylinder 5, the second perforated cylinder 5 is separated from the shell 1 by a cavity 6, and both ends of the first perforated cylinder 3 are provided with auxiliary sound-absorbing structures.

[0026] In a preferred embodiment, the auxiliary noise reduction structure includes an interval noise reduction structure 7 and a rotating noise reduction structure 8. Different structural configurations provide multiple diffraction paths for sound waves, adapting to multi-frequency noise reduction in conjunction.

[0027] In a preferred embodiment, the spaced noise reduction structure 7 includes a plurality of semi-circular perforated covers 9 arranged at intervals, and a second noise reduction layer 10 is provided inside the semi-circular perforated covers 9.

[0028] In a preferred embodiment, the height of the semi-circular perforated cover 9 exceeds the radius of the first perforated cylinder 3. This completely seals off the central cavity of the first perforated cylinder 3, ensuring sound wave diffraction.

[0029] In a preferred embodiment, the rotating noise-absorbing structure 8 includes a plurality of fan-shaped perforated covers 11 arranged around the center of the first perforated cylinder 3 and spaced apart, and a third noise-absorbing layer 12 is provided inside the fan-shaped perforated covers 11.

[0030] In a preferred embodiment, the height of the fan-shaped perforated cover 11 exceeds the radius of the first perforated cylinder 3. Completely sealing the central cavity of the first perforated cylinder 3 ensures sound wave diffraction.

[0031] In the preferred embodiment, the rotating silencing structure 8 completely blocks the line of sight from one side of the first perforated cylinder 3, making it impossible to directly see the other side of the first perforated cylinder 3. This completely seals off the central cavity of the first perforated cylinder 3, ensuring sound wave diffraction.

[0032] Example 2:

[0033] like Figure 2-4 In the middle, the height of the semi-circular hole cover 9 exceeds the radius of the first perforated cylinder 3. Three semi-circular hole covers 9 are set in each group, forming an upside-down interval arrangement. The sound cannot pass directly through the middle cavity of the first perforated cylinder 3 and needs to be diffracted through the interval silencing structure 7.

[0034] Example 3:

[0035] like Figure 5 and 6 In the middle, the height of the fan-shaped hole cover 11 also exceeds the radius of the first perforated cylinder 3. Each group of three fan-shaped hole covers 11 can be divided into sixty-degree fan shapes. The front and rear groups of six fan-shaped hole covers 11 completely block the middle cavity of the first perforated cylinder 3, which needs to be diffracted by the rotating silencer structure 8.

[0036] Each group of three fan-shaped perforated covers 11 can be evenly divided into 120-degree fan shapes. Three fan-shaped perforated covers 11 on one side can completely block the middle cavity of the first perforated cylinder 3, which needs to be diffracted by the rotating silencing structure 8.

[0037] The method of using this utility model is as follows: the sound wave enters the outer shell 1 through the interface 2, first passes through the perforation of the first perforated cylinder 3, and comes into contact with the first sound-absorbing layer 4. The low- and mid-frequency sound waves are absorbed by the sound-absorbing material; the high-frequency sound waves are reflected or attenuated by the resistance effect, the change in the aperture of the first and second perforated cylinders, and the cavity reflection.

[0038] Interval silencing structure 7: The second silencing layer 10 inside the semi-circular perforated cover 9 reflects the vertical sound waves twice, while the micro-perforated plate further absorbs the high-frequency components; Rotating silencing structure 8: The fan-shaped perforated cover 11 forces the sound waves to travel along a circular path, and the honeycomb structure and the third silencing layer 12 absorb the remaining sound energy through the porous medium; The airtightness of the rotating structure 8 ensures that the sound waves cannot pass through directly and must pass through all silencing layers to avoid high-frequency leakage.

[0039] The cavity 6, as a resistive cavity, forms a Helmholtz resonant cavity by matching the aperture of the second perforated cylinder 5, further attenuating sound waves of specific frequencies, while forming a composite noise reduction with the resistive material.

[0040] The beneficial effects of this invention are: wideband and high-efficiency noise reduction; high-frequency sound waves are reflected by aperture changes to achieve wideband coverage; at the same time, a three-dimensional sound-absorbing network is formed to further disperse the sound wave path and enhance attenuation; it ensures that the sound wave must bypass multiple sound-absorbing layers, improving the noise reduction efficiency per unit volume, and preventing the sound wave from directly penetrating the gap, thus enhancing the airtightness; the overall structure of the device is simple, and the multi-layer damping setting optimizes the attenuation of sound waves of different frequencies, forcing the sound wave to reflect and diffract multiple times, significantly improving the sound absorption quality.

Claims

1. An impedance composite silencer, comprising a housing (1), characterized in that: The outer shell (1) has a connection interface (2) at both ends. A first perforated cylinder (3) is provided inside the connection interface (2). A first sound-absorbing layer (4) is wrapped around the outside of the first perforated cylinder (3). A second perforated cylinder (5) is wrapped around the outside of the first sound-absorbing layer (4). A cavity (6) is separated between the second perforated cylinder (5) and the outer shell (1). Auxiliary sound-absorbing structures are provided at both ends of the first perforated cylinder (3).

2. The impedance composite silencer according to claim 1, characterized in that: The auxiliary noise reduction structure includes an interval noise reduction structure (7) and a rotating noise reduction structure (8).

3. The impedance composite silencer according to claim 2, characterized in that: The aforementioned spaced noise reduction structure (7) includes multiple semi-circular perforated covers (9) arranged vertically at intervals, and a second noise reduction layer (10) is provided inside the semi-circular perforated covers (9).

4. The impedance composite silencer according to claim 3, characterized in that: The height of the semi-circular perforated cover (9) exceeds the radius of the first perforated cylinder (3).

5. The impedance composite silencer according to claim 2, characterized in that: The rotating noise reduction structure (8) includes multiple fan-shaped perforated covers (11) arranged around the center of the first perforated cylinder (3) and spaced apart, with a third noise reduction layer (12) inside the fan-shaped perforated covers (11).

6. The impedance composite silencer according to claim 5, characterized in that: The height of the fan-shaped perforated cover (11) exceeds the radius of the first perforated cylinder (3).

7. The impedance composite silencer according to claim 2, characterized in that: The rotating silencing structure (8) completely blocks the line of sight when viewed from one side of the first perforated cylinder (3), making it impossible to see the other side of the first perforated cylinder (3).

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