Composite sound-absorbing device with built in resonant cavity

a sound-absorbing device and cavity technology, applied in the field of composite sound-absorbing devices with built-in resonant cavities, can solve the problems of not being wide enough, unable to meet some practical needs of noise control engineering, and being almost impossible to realize in practice, so as to increase the acoustic impedance of the perforated board, and consume enough acoustic energy

Inactive Publication Date: 2012-10-04
INST OF ACOUSTICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This patented technology describes an improved loudspeaker design called a resonating chamber (RC). It uses tiny holes at certain positions along its walls instead of large ones like openings. These minute holes allow some sounds outside through them while others enter deeper spaces. They act together when sound waves hit these microscopic holes create interference between them causing further amplification of their own amplitude. Additionally, they have varying sizes and shapes of pore structures depending upon factors such as volume, pressure, temperature, etc., allowing for more effective sound reduction without compromising overall performance. Overall, this new design provides better sound reception than previous designs due to increased efficiency and decreased sensitivity compared to existing devices.

Problems solved by technology

The technical problem addressed in this patents relates to improving the efficiency at reducing noise levels from various sources such as engines due to lower frequencies caused by smaller sizes without compromising effective absorbency properties. Existing methods involve adding layers of foam padding or inserting wires into certain spaces between them, resulting in decreased volume capacity compared to other designs. Additionally, existing techniques require larger openings in order to achieve better sound quality, leading to reduced usable space requirements.

Method used

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  • Composite sound-absorbing device with built in resonant cavity
  • Composite sound-absorbing device with built in resonant cavity
  • Composite sound-absorbing device with built in resonant cavity

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Experimental program
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embodiment one

[0036]Referring to FIG. 1, the embodiment provides a composite sound-absorbing device with built-in resonant cavity. The device comprises a closed cavity formed by a perforated board 1, a back board 2 and side boards 3 all made up of stainless steel, wherein the depth D of the closed cavity is 40 mm. The perforated board 1 is a square board with the length of the side being 80 mm and the thickness being 5 mm. On the perforated board 1, first pores 6, with a diameter of 3 mm, are formed. The perforation rate σ of the first pores 6 is 28%. The first pores 6 are regularly arranged in the pattern of a square on the perforated board 1. In the closed cavity, four resonant cavities 5 are formed, with each resonant cavity 5 being made of aluminum and having a shape of sphere. The volume of the resonant cavity 5 is 1.4×104 mm3 and the thickness of the wall of the resonant cavity 5 is 5 mm. Moreover, on the wall of the resonant cavity 5, a second pore 6′, with a diameter of 2 mm, is formed. The

embodiment two

[0037]Referring to FIG. 2, the present embodiment provides a composite sound-absorbing device with built-in resonant cavity according to the present invention. The device comprises a closed cavity formed by a perforated board 1, a back board 2 and side boards 3 all made of stainless steel, wherein the depth D of the closed cavity is 50 mm. The perforated board 1 is a round board, with a diameter of 100 mm and a thickness of 0.7 mm. On the perforated board 1, first pores 6, with a diameter of 1.7 mm, are formed. The perforation rate σ of the first pores 6 is 4.6%. The first pores 6 are arranged regularly in the pattern of a square on the perforated board 1. In the closed cavity, four resonant cavities are formed, with each resonant cavity being made of plastic. The volume of the resonant cavity 5 is 3.35×104 mm3 and the thickness of the wall of the resonant cavity 5 is 0.4 mm. Furthermore, there are 26 second pores 6′ on the wall of the resonant cavity 5, evenly distributed on the circu

embodiment three

[0042]Referring to FIG. 2, the embodiment provides a composite sound-absorbing device with built-in resonant cavity. The device comprises a closed cavity formed by a perforated board 1, a back board 2 and side boards 3 all made up of stainless steel, with the depth D of the closed cavity being 100 mm. The perforated board 1 is a round board, with a diameter of 100 mm and thickness of 0.7 mm. On the perforated board 1, first pores 6, with a diameter of 1.7 mm are formed. The perforation rate of the first pores 6 is 4.6%. The first pores 6 are arranged regularly in a pattern of square on the perforated board 1. Separately, nine, seven, four and one resonant cavity 5, made of plastic and having a shape of sphere and a volume V of 3.35×104 mm3 and the thickness of the wall of the resonant cavity 5 being 0.4 mm, is arranged in the closed cavity. Furthermore, there are 26 second pores 6′ on the wall of the resonant cavity 5, evenly distributed on the circumferences of three mutually perpendi

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Abstract

The composite sound-absorbing device of the present invention includes a perforated board having a number of first pores thereon, a back board and side boards, the perforated board, back board and side boards forming a closed cavity, wherein: at least one or more of the resonant cavities being located within the closed cavity; at least one or more of second pores being located on the resonant cavities; at least one of the second pores being connected with the closed cavity; the resonant cavity having a volume of V=10 mm3 −1×1010 mm3, having a thickness of 0.05 mm-10 mm, the second pores having an aperture of d′=0.05-100 mm, with a perforation rate σ′=0.01%-30%. The present invention is beneficial to improve the effect of sound-absorbing and expand the frequency band of sound-absorbing.

Description

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Claims

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Application Information

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Owner INST OF ACOUSTICS CHINESE ACAD OF SCI
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