Perforated plate resonance sound absorption device possessing built-in cavity

Abstract

The invention discloses a perforated plate resonance sound absorption device possessing a built-in cavity. The device comprises a perforated plate and a plate rear cavity. A closed cavity is arranged in the perforated plate. An internal portion space of the cavity is filled with at least one of a liquid and a solid particle. In the invention, through arranging the closed cavity in the perforated plate and filling a sound absorption material in the cavity, a sound absorption coefficient of the perforated plate resonance sound absorption device is effectively increased and a sound absorption frequency band is widened. Under the condition that a volume is not increased, a suitable scope of the device is increased.

Description

technical field [0001] The invention relates to the technical field of sound absorption and noise reduction, in particular to a perforated plate resonance sound absorption device with a built-in cavity. Background technique [0002] The resonant sound-absorbing structure is a sound-absorbing body designed using the principle of resonant sound-absorbing. Under the excitation of sound waves, the vibrating structure converts part of the vibration energy into heat energy due to its own internal friction and air friction. According to energy conservation According to the law, the energy of these losses must come from the sound energy that excites them to vibrate. When the frequency of the incident sound wave coincides with the natural frequency of the structure, the structure will resonate, and the energy loss caused by this time, that is, the sound absorption coefficient of the component, is the largest. [0003] Common resonant sound-absorbing structures include thin-plate sou...

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Problems solved by technology

However, the sound absorption frequency band of this structure is limited to the middle and low frequencies, and the sound absorption frequency band is not wide enough

[0006] Patent document CN101645263B discloses a tube bundle perforated plate composite resonance sound-absorbing device. On the basis of the above structure, a layer of porous sound-absorbing material is covered on the outer surface of the perforated plate. Although the sound absorption coefficient of the structure for medium and high-frequency sound can be further improved, the The thickness of the structure will increase, the surface strength of the structure will decrease, and sometimes it will cause secondary pollution

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