CN207602217U - A kind of cavity resonance-gradient acoustical cotton - Google Patents

Abstract

The utility model relates to a cavity resonance-gradient sound-absorbing cotton, which comprises a cavity resonance sound-absorbing layer, a gradient sound-absorbing layer and a magnetic layer arranged sequentially from top to bottom, and the layers are bonded by an adhesive or a hot-melt film , the cavity resonant sound-absorbing layer is a flat plate structure, and there are multiple resonant cavities on the upper surface. The resonant cavity includes an internal cavity and a connecting neck. The internal cavity communicates with the outside through the connecting neck. hole, the gradient sound-absorbing layer includes the first gradient sound-absorbing layer and the second gradient sound-absorbing layer arranged up and down. The density of the layers is set from top to bottom, and the density of the sound-absorbing layer of the second gradient sound-absorbing layer is set from top to bottom. The gradient sound-absorbing layer can completely prevent the sound of various frequencies from penetrating the sound-absorbing layer, and its composite structure with the cavity resonance sound-absorbing layer can achieve better sound-absorbing effect.

Description

A cavity resonance-gradient sound-absorbing cotton

technical field

The utility model relates to the field of sound-absorbing cotton, in particular to cavity resonance-gradient sound-absorbing cotton.

Background technique

Gradient sound-absorbing cotton is a laminated step-density porous sound-absorbing material. The sound-absorbing mechanism is that there are a large number of tiny connected pores inside the material. Sound waves can penetrate deep into the material along these pores, and friction with the material converts sound energy into heat energy. However, the density of the existing gradient sound-absorbing cotton is usually set to increase or decrease. Although a better sound-absorbing effect can be achieved, its asymmetric structure may cause sound penetration and affect the sound-absorbing effect.

The outer space of the material is connected to the inner cavity through a narrow bottleneck. When the sound wave is incident, at the resonant frequency, a severe resonance occurs between the air in the neck and the inner space, and the sound energy is lost. The characteristic of Helmholtz resonance absorption is that it only has a large sound absorption coefficient at the resonance frequency. Generally, the sound absorption frequency band of the resonance sound absorption structure is relatively narrow. Near the resonance frequency, the sound absorption coefficient is very high, which can be close to 1, but if once If it deviates from the resonance peak, the sound absorption coefficient will drop rapidly, so it is only suitable for single-frequency sound materials that absorb middle and low frequencies. In order to obtain broadband noise reduction materials, most of them are made into sandwich structures to improve their sound absorption performance.

Utility model content

The technical problem to be solved by the utility model is to provide a cavity resonance-gradient sound-absorbing cotton.

The technical scheme that the utility model solves the problems of the technologies described above is as follows:

A cavity resonance-gradient sound-absorbing cotton, comprising a cavity resonance sound-absorbing layer, a gradient sound-absorbing layer and a magnetic layer arranged sequentially from top to bottom, each layer is bonded by adhesive or hot-melt film, the cavity The cavity resonance sound-absorbing layer is a flat plate structure, and there are multiple resonance cavities on the upper surface. The resonance cavity includes an internal cavity and a connecting neck. The internal cavity communicates with the outside through the connecting neck. There are a plurality of through holes, and the gradient sound-absorbing layer includes a first gradient sound-absorbing layer and a second gradient sound-absorbing layer arranged up and down, and the first gradient sound-absorbing layer and the second gradient sound-absorbing layer are composed of multiple layers of sound-absorbing layers with different densities , the density of the sound-absorbing layer of the first gradient sound-absorbing layer is set to increase in density from top to bottom, and the density of the sound-absorbing layer of the second gradient sound-absorbing layer is set to decrease in density from top to bottom.

Further, the magnetic layer is a magnetic body formed by mixing and bonding magnetic powder with plastic or rubber as an adhesive.

Further, the first gradient sound-absorbing layer and the second gradient sound-absorbing layer are composed of the same multi-layer sound-absorbing layer, and only the arrangement order of the sound-absorbing layers is different.

The beneficial effects of the utility model are: the resonant sound-absorbing structure generally has a relatively narrow sound-absorbing frequency band, and the sound-absorbing coefficient is very high near the resonant frequency, which is generally used for low-frequency sound-absorbing, and the gradient sound-absorbing layer is composed of the first gradient sound-absorbing layer whose density increases from top to bottom And it is composed of the second gradient sound-absorbing layer with decreasing density from top to bottom, which can completely prevent the sound of various frequencies from penetrating the sound-absorbing layer, and its composite structure with the cavity resonance sound-absorbing layer can achieve better sound-absorbing effect; this practical The new cavity resonant sound-absorbing layer is also provided with through holes, through which sound can pass through the cavity resonant sound-absorbing layer and enter the gradient sound-absorbing layer, so that the sound can be absorbed by the gradient sound-absorbing layer and enhance the sound-absorbing effect. The setting of the magnetic layer can make the sound-absorbing cotton easy to install, and the sound-absorbing cotton can be directly adsorbed on the ferrous metal, or a corresponding adsorption part is provided at the installation position, and the magnetic layer is installed on the adsorption part.

Description of drawings

Fig. 1 is a schematic cross-sectional structure diagram of the utility model.

In the accompanying drawings, the list of parts represented by each label is as follows:

1. Cavity resonance sound-absorbing layer; 2. Gradient sound-absorbing layer; 3. Magnetic layer; 4. Through hole; 5. Resonant cavity; 21. The first gradient sound-absorbing layer; 22. The second gradient sound-absorbing layer

Detailed ways

The principles and features of the present utility model are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the utility model, and are not used to limit the scope of the utility model.

As shown in Figure 1, a cavity resonance-gradient sound-absorbing cotton, including a cavity resonance sound-absorbing layer 1, a gradient sound-absorbing layer 2 and a magnetic layer 3 arranged in sequence from top to bottom, between each layer through an adhesive or Hot-melt film bonding, the cavity resonant sound-absorbing layer 1 is a flat plate structure, and a plurality of resonant cavities 5 are opened on the upper surface, and the resonant cavities 5 include internal cavities and connecting necks, and the internal cavities are connected by connecting The neck is connected with the outside world, and a plurality of through holes 4 are opened on the flat plate. The gradient sound-absorbing layer 2 includes a first gradient sound-absorbing layer 21 and a second gradient sound-absorbing layer 22 arranged up and down. The first gradient sound-absorbing layer 21 and the second gradient sound-absorbing layer 22 are composed of multiple layers of sound-absorbing layers with different densities, the density of the first gradient sound-absorbing layer 21 is set from top to bottom, and the density of the second gradient sound-absorbing layer 22 is from Decreasing density setting from top to bottom.

The magnetic layer 3 is a magnetic body made of plastic or rubber as an adhesive, mixed and bonded with magnetic powder.

The first gradient sound-absorbing layer 21 and the second gradient sound-absorbing layer 22 can be a symmetrical gradient density or an asymmetric gradient density. In this embodiment, the first gradient sound-absorbing layer 21 and the second gradient sound-absorbing layer 22 are a symmetrical gradient density, that is, the The first gradient sound-absorbing layer 21 and the second gradient sound-absorbing layer 22 are composed of the same multi-layer sound-absorbing layer, and only the arrangement order of the sound-absorbing layers is different.

Cavity resonance sound absorption is called Helmholtz resonance sound absorption. The sound absorption principle is similar to the acoustic resonance of a thermos bottle. The outer space of the material is connected to the inner cavity through a narrow bottleneck. When the sound wave is incident, at the resonance frequency, the neck Acoustic energy is lost due to severe resonance between the air and the interior space. The characteristic of Helmholtz resonance absorption is that it has a large sound absorption coefficient only at the resonance frequency, and its sound absorption frequency band is relatively narrow, and the sound absorption coefficient near the resonance frequency is very high. It is generally used for low-frequency sound absorption. The gradient sound-absorbing layer is composed of The first gradient sound-absorbing layer with increasing density from top to bottom and the second gradient sound-absorbing layer with decreasing density from top to bottom can completely prevent the sound of various frequencies from penetrating the sound-absorbing layer, and its composite with the cavity resonance sound-absorbing layer The structure can achieve a better sound-absorbing effect; the cavity resonant sound-absorbing layer of the utility model is also provided with a through hole, and the sound can pass through the cavity resonant sound-absorbing layer and enter the gradient sound-absorbing layer through the through-hole, so that the sound can be absorbed by the gradient sound-absorbing layer , enhance the sound-absorbing effect. The setting of the magnetic layer can make the sound-absorbing cotton easy to install, and the sound-absorbing cotton can be directly adsorbed on the ferrous metal, or a corresponding adsorption metal is provided at the installation position, and the magnetic layer is installed on the adsorption metal.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (3)

1. A cavity resonance-gradient sound-absorbing cotton is characterized in that it comprises a cavity resonance sound-absorbing layer (1), a gradient sound-absorbing layer (2) and a magnetic layer (3) arranged sequentially from top to bottom. The cavity resonant sound-absorbing layer (1) is a flat plate structure, and the upper surface has a plurality of resonant cavities (5), and the resonant cavity (5) includes an internal cavity and the connecting neck, the internal cavity communicates with the outside world through the connecting neck, a plurality of through holes (4) are opened on the flat plate, and the gradient sound-absorbing layer (2) includes the first gradient sound-absorbing layer arranged up and down (21) and the second gradient sound-absorbing layer (22), the first gradient sound-absorbing layer (21) and the second gradient sound-absorbing layer (22) are all made up of multi-layer sound-absorbing layers with different densities, and the first gradient sound-absorbing layer (21 The density of the sound-absorbing layer of ) is set from top to bottom, and the density of the sound-absorbing layer of the second gradient sound-absorbing layer (22) is set from top to bottom. 2. The cavity resonance-gradient sound-absorbing cotton according to claim 1, characterized in that the magnetic layer (3) is a magnetic body made of plastic or rubber as an adhesive, mixed with magnetic powder and bonded. 3. The cavity resonance-gradient sound-absorbing cotton according to claim 1, characterized in that, the first gradient sound-absorbing layer (21) and the second gradient sound-absorbing layer (22) are composed of the same multi-layer sound-absorbing layer, only The arrangement order of the sound-absorbing layers is different.