Broadband perforated plate sound-absorbing structure

Abstract

The invention discloses a sound-absorbing structure of a broadband perforated plate, which comprises a perforated plate with multiple perforations and a cavity structure with an open end. The perforated plate is arranged at the open end of the cavity structure. The cavity structure includes a bottom plate opposite to the open end and a surrounding plate fixed on the bottom plate. The bottom plate and the surrounding plate form a chamber. Wherein, the chamber has at least two subchambers extending from the open end of the chamber to the direction of the bottom plate, at least one of the subchambers in the at least two subchambers has a bottom space formed between the bottom and the bottom plate, and the bottom space is connected with other subchambers. At least one sub-chamber in the chamber communicates. The invention can effectively widen the sound-absorbing frequency band without increasing the overall depth of the chamber, and improve the sound-absorbing capacity of the perforated plate, avoiding the use of rice-level perforations, and reducing the manufacturing cost.

Description

technical field [0001] The present invention generally relates to the technical field of noise control, in particular to a sound-absorbing structure based on a perforated plate and a cavity. Background technique [0002] The sound-absorbing structure mainly includes two types: fiber sound-absorbing material and perforated plate sound-absorbing structure. [0003] Fiber sound-absorbing materials, such as glass fiber and mineral wool, have a wide sound-absorbing frequency band, but they are usually not ideal for low-frequency noise processing; moreover, they are not suitable for use in many occasions due to factors such as easy to produce bacteria and pollute the environment. [0004] The sound-absorbing structure of the perforated plate includes a perforated plate and a cavity with a certain depth, wherein the perforated plate is perforated with holes with a diameter less than 0.5mm. The perforated plate sound-absorbing structure has the advantages of cleanliness, high tempe...

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Problems solved by technology

However, due to the coupling of the parameters of the mass-spring system (spring stiffness and mass) and the air inside the cavity, this system is difficult to realize in practical applications

[0007] Chinese invention patent 00100641.X discloses a tube bundle type perforated plate resonant sound absorbing device, which inserts an open end of a tube bundle formed by arranging tubes with a number equal to or less than the number of holes on the perforated plate into the cavity on the perforated plate. The sound-absorbing frequency band, especially the low-frequency sound-absorbing performance has a certain effect, but the production process of the sound-absorbing device is complicated and the cost is high

[0008] Another disadvantage of the traditional perforated plate sound-absorbing structure is that when the perforated plate adopts an easier-to-process aperture size, such as a diameter of 0.5mm to 1mm, its sound absorption capacity is far from sufficient compared with traditional fiber sound-absorbing materials. In order to obtain more For a good sound absorption effect, it is necessary to adopt a hole diameter of 0.1mm to 0.2mm or even smaller, which greatly increases the difficulty and cost of processing

Compared with the mechanical processing technology of ordinary perforated plate (perforation diameter 0.5mm ~ 2mm) commonly used in the industry at present, the processing process of the above-mentioned processing of silk-meter-level micro-holes is complicated and the production cost is high.

[0009] The shortcomings or defects of the above-mentioned traditional perforated plate sound absorption structure can be simply attributed to: (1) The sound absorption frequency band is not wide enough, and low-frequency sound absorption requires a large cavity depth, which is limited by the installation space in practical applications, and the feasibility is poor; (2) ) A good sound absorption effect requires a perforation diameter of the rice meter level, which increases the cost of making perforated panels

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