A composite sound-absorbing structure

A technology of sound absorption and panel, applied in the direction of sound-generating equipment, instruments, etc., can solve the problems of poor sound absorption, poor sound absorption effect, low frequency sound absorption effect, etc., and achieve the effect of wide sound absorption frequency band and sound absorption performance improvement.

Inactive Publication Date: 2011-12-28
周国柱
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This sound-absorbing structure also has some significant disadvantages: strong frequency selectivity, good sound-absorbing performance only in certain specific frequency bands, and the sound-absorbing effect is significantly worse when it deviates from these frequency bands
However, since the sound-absorbing frequency band of the added porous material is mainly concentrated in the high frequency, the resonant sound-absorbing structure after adding the porous material is still not ideal for absorbing the middle and low frequency sound, and the frequency band with relatively poor sound absorption is prone to appear.
Increasing the thickness of the porous material or reducing the porosity of the material can improve the sound absorption effect of the structure on the middle and low frequency sound, and also lead to a decrease in the absorption effect of the high frequency sound

Method used

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  • A composite sound-absorbing structure
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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] refer to figure 1 . The composite sound-absorbing structure is composed of glass wool encapsulated by an upper panel 2 , a lower panel 3 and a side panel 4 . The space enclosed by the upper panel 2, the lower panel 3 and the side panel 4 is filled with glass wool; from the upper panel 2 to the lower panel 3, the porosity of the filled glass wool gradually changes from small to large or from large to small . The upper panel 2 is made of an iron plate with a perforation rate of 10%, a thickness of 1.2 mm, and a perforation diameter of 1.2 mm; the lower panel 3 and the side panels 4 are all non-porous iron plates with a thickness of 1.2 mm. The shape of the composite sound-absorbing structure is a cuboid, and the distance from the upper panel 2 to the lower panel 3 is equal to 6 cm.

[0028] The composite sound-absorbing structure proposed in this example can be installed on the surface of the wall to reduce the sound level in the room; it can also be used as the side w...

Embodiment 2

[0030] refer to figure 1 . The composite sound-absorbing structure is composed of a porous material 1 encapsulated by an upper panel 2 , a lower panel 3 and a side panel 4 . The space enclosed by the upper panel 2 , the lower panel 3 and the side panel 4 is filled with the porous material 1 ; the porosity of the porous material 1 decreases uniformly from 99% to 90% from the upper panel 2 to the lower panel 3 . The porous material 1 is made of one of polyurethane foam or urea foam. The upper panel 2 is made of an iron plate with a perforation rate of 5%, a thickness of 1.2 mm, and a perforation diameter of 1.5 mm; the lower panel 3 and the side panels 4 are all non-porous iron plates with a thickness of 1.2 mm. The shape of the composite sound-absorbing structure is a cuboid, and the distance from the upper panel 2 to the lower panel 3 is equal to 6 cm.

[0031] The composite sound-absorbing structure proposed in this example can be installed on the surface of the wall to re...

Embodiment 3

[0033] refer to figure 1 . The composite sound-absorbing structure is composed of glass wool encapsulated by an upper panel 2 , a lower panel 3 and a side panel 4 . The space enclosed by the upper panel 2, the lower panel 3 and the side panel 4 is filled with glass wool; the bulk density of the filled glass wool is from 48Kg / m in the direction from the upper panel 2 to the middle position of the upper and lower panels 3 Gradually increase to 128Kg / m 3 ; Between the lower panel 3 and the middle position of the upper and lower panels, the bulk density of the filled glass wool is from 48Kg / m in the direction from the lower panel 3 to the middle position of the upper and lower panels 3 Gradually increase to 128Kg / m 3. Both the upper panel 2 and the lower panel 3 are made of an iron plate with a perforation rate of 6.5%, a thickness of 1 mm, and a perforation diameter of 1.2 mm; the side panel 4 is made of a non-porous iron plate with a thickness of 1.2 mm. The shape of the co...

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Abstract

The invention relates to a composite sound-absorbing structure made of porous material and resonance structure. The composite sound-absorbing structure is composed of porous materials encapsulated by upper panels, lower panels and side panels. From the upper panel to the lower panel, the void size or porosity of the porous material gradually changes in order from small to large or from large to small; the space enclosed by the upper panel, the lower panel and the side panel is filled with porous material 1; the upper panel It is a perforated plate, and the lower panel is a perforated plate or a non-porous baffle. The composite sound-absorbing structure proposed by the present invention has a wider sound-absorbing frequency band than the porous material with uniform pore size and porosity, which can improve the sound-absorbing performance in the middle and low frequency bands while maintaining the sound absorption in the high-frequency band. Sound absorption performance.

Description

technical field [0001] The invention relates to a sound-absorbing structure, in particular to a composite sound-absorbing structure made of a porous material and a resonant structure. Background technique [0002] Sound absorption technology is widely used in noise control. Resonant sound-absorbing structures and porous materials are currently commonly used sound-absorbing structures. [0003] Commonly used resonant sound-absorbing structures include single resonator, sheet resonant sound-absorbing structure, film resonant sound-absorbing structure, slit resonant sound-absorbing structure, perforated plate and micro-perforated plate resonant sound-absorbing structure, etc. These resonant sound-absorbing structures work similarly to "Helmholtz" resonators. When the frequency of the incident sound wave is close to the resonant frequency of the system, the reciprocating vibration of the air will be subject to greater friction and damping, so that the sound energy will be conv...

Claims

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Application Information

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IPC IPC(8): G10K11/172G10K11/16
Inventor 周国柱
Owner 周国柱
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