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Super wide frequency band micropunching acoustical body and its producing method and equipment

A technology of micro-perforation and sound-absorbing body, which is applied to building components, sound insulation, etc., and can solve problems such as complex installation and construction

Inactive Publication Date: 2004-09-22
INST OF ACOUSTICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When using this structure, the installation and construction are more complicated, and higher technology is required to ensure the quality.

Method used

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  • Super wide frequency band micropunching acoustical body and its producing method and equipment
  • Super wide frequency band micropunching acoustical body and its producing method and equipment
  • Super wide frequency band micropunching acoustical body and its producing method and equipment

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Embodiment

[0092] Such as figure 1 with figure 2 As shown, the ultra-wideband microperforated sound absorber of the present invention includes a microperforated plate 1 and a box-shaped member 2 with a back cavity depth D=285mm integrated with the microperforated plate 1. The perforated plate constant K of the microperforated plate 1 =1, relative acoustic resistance r=1, the micro-perforated plate 1 and the box-shaped member 2 are made of aluminum plate, the plate thickness t is equal to 0.2mm, the perforation diameter of the micro-perforated plate 1 is d=0.2mm, and the perforation rate P=0.3% , The perforation is arranged in a square lattice, and the hole distance b=2.0mm. The ultra-wideband micro-perforated sound absorber is 1000mm long and 800mm wide. In order to strengthen its strength, the micro-perforated plate 1 is pressed into a corrugated shape, and 20 pieces of 20×20mm in size are arranged in the box-shaped member 2 2 The square support baffle grid 3 is arranged in four horizonta...

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Abstract

A sound absorbing body with micro punching for super wide frequency band includes micro punching sheet, a case structure pipe having D depth back cavity integrated with micro punch hole sheet. The constant of punching on the micro punch hole sheet is formula 1, relative acoustic resistance is formula 2 and 1 is no larger than r, r no larger than 5 in the formula, the back cavity depth is formula 3. In the formula, d refering to hole diameter mm, omega refining to angle frequency, rho vefering to air density 1.2 kg m, eta refering to coefficient viscosity 0.000018 kg / ms. in the air, rho refering to punching rate percentage of micro punch hole sheet, rho c refering to chracteristic impedance 400 kg-1 in the air, t refering to thickness mm of micro punch hole sheet, kr refering to relative acoustic resistance constant, lambda refering to the legnth m of sound wave, c refering to acoustic speed 340 m / s in the air, of refering miximum sound absorbing frequency.

Description

Technical field [0001] The invention relates to a sound-absorbing structure, in particular to a super-wideband micro-perforated sound-absorbing body. Background technique [0002] The sound-absorbing structure of the currently used micro-perforated plate has a much wider sound absorption frequency band than other resonance sound-absorbing structures, but only has 1 to 2 octave bands. In order to further increase the width of the sound absorption frequency band, a double-layer micro-perforated plate sound absorption structure is required in practical applications. When using this structure, the installation and construction are more complicated and require high technology to ensure the quality. In addition, in practical applications, sound waves are not only incident normally, but also incident in different directions. Therefore, the absorption characteristic is the average of incidence in all directions. If it is assumed that the probability of incidence in all directions is the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E04B1/86
Inventor 马大猷刘克
Owner INST OF ACOUSTICS CHINESE ACAD OF SCI