A low-frequency coupling sound absorbing structure

Abstract

The invention discloses a low-frequency coupling sound absorbing structure, comprising a peripheral cavity, a resonant cavity arranged in the peripheral cavity and an extension pipe structure arrangedin the resonant cavity. One end of the extension pipe structure is connected with the cavity wall of the resonant cavity through a corresponding through hole. The peripheral cavity comprises a micro-perforated plate, a back plate, a first side plate and a second side plate. The micro-perforated plate is provided with a plurality of micro-hole structures, the micro-perforated plate is arranged corresponding to the back plate, and the first side plate and the second side plate are arranged corresponding to the back plate. The low-frequency coupling sound absorbing structure in the present invention can increase the acoustic impedance of the sound absorbing structure by arranging a resonant cavity with an elongated tube structure in the peripheral cavity with the microporous structure, thereby facilitating the sound absorbing coefficient to be increased and the sound absorbing band to be widened, shifting the sound absorbing band to the low frequency, thereby realizing the low-frequencysound absorbing and contributing to the improvement of the product performance.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of noise reduction, in particular to a low-frequency coupling sound-absorbing structure. Background technique [0002] At present, sound-absorbing materials can be roughly divided into porous sound-absorbing materials and resonant sound-absorbing materials according to the sound-absorbing principle. Acoustic and micro-slit plate sound-absorbing structures are all resonant sound-absorbing structures. Micro-perforated plate resonance, micro-perforated plate sound-absorbing structure, and double-layer micro-perforated plate sound-absorbing structure are more porous. Still can not meet the actual needs of some noise control, especially in the occasions where the sound absorption space is strictly limited, it is difficult to control low-frequency noise. [0003] Because sound waves with large wavelengths in the low-frequency range cannot be effectively controlled, and low-frequency sound w...

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Problems solved by technology

Micro-perforated plate resonance, micro-perforated plate sound-absorbing structure, and double-layer micro-perforated plate sound-absorbing structure are more porous. It still cannot meet the actual needs of some noise control, especially in the occasion where the sound absorption space is strictly limited, it is difficult to control low-frequency noise

[0003] Because sound waves with large wavelengths in the low-frequency range cannot be effectively controlled, and low-frequency sound waves are not easily attenuated in the air, the propagation distance is long, and the range of influence is large. Therefore, in the prior art, in order to effectively reduce low-frequency noise, it is necessary to greatly increase the sound-absorbing material. The thickness of the sound-absorbing structure or the cavity depth of the sound-absorbing structure will increase the volume of the sound-absorbing structure, which is not conducive to the development of product miniaturization. In addition, the increase in the cavity depth of the sound-absorbing structure will also lead to a narrowing of the sound-absorbing frequency band to a certain extent. reduce product performance

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