Low-frequency light and thin sound insulation structure

Abstract

The invention discloses a low-frequency light and thin sound insulation structure, a thickness calculation method and application, the low-frequency light and thin sound insulation structure comprises a bottom plate, a partition plate, a perforated plate and a porous material which are sequentially arranged from bottom to top, the partition plate is of a concentric-square-shaped structure, and the porous material is located in a mounting cavity defined by the bottom plate, the partition plate and the perforated plate; the bottom plate, the partition plate, the perforated plate and the porous material are combined together to achieve low-frequency sound insulation. The sound insulation characteristics of thin plate resonance, the porous material and the micro-perforated plate + cavity are effectively combined together, according to the environment sound insulation requirement, double-side low-frequency sound insulation is achieved, the sound insulation performance of the thin plate side is better than that of the perforated plate side, the sound insulation amount is higher than 30 dB, and the low-frequency sound insulation performance is excellent.

Description

Technical Field

[0001] The present invention relates to the technical field of sound insulation, and particularly relates to a low-frequency thin and light sound insulation structure. Background Art

[0002] With the rapid development of industries such as manufacturing, urban construction, automobiles, high-speed rails, urban rail transit, and air transportation, the noise generated by their production and construction will inevitably have a negative impact on people's lives and work. Research shows that people who work or live in a noisy environment for a long time often feel upset, angry easily, have hearing loss, be in a trance, etc., causing varying degrees of damage to the human body's physiology. Therefore, it is particularly important to strengthen the control of environmental noise pollution and create a comfortable and quiet working environment.

[0003] However, according to the characteristics of noise, it is generated by a noise source, propagated, and transmitted to the receiver. Corresponding to this, there are three methods for noise control, namely, implementing noise reduction on the noise source, cutting off or attenuating on the propagation path, and protecting the receiver. Practice shows that implementing blocking and attenuation on its propagation path is one of the effective methods and ways for noise reduction. For this reason, on the one hand, the present invention absorbs the advantages of the combined low-frequency sound absorption of "micro-perforation + cavity" and the mid-high frequency sound absorption of porous materials; on the other hand, by utilizing the blocking and resonance characteristics of the plate to noise, a new sound insulation structure of a combination of micro-perforated plate + porous material + thin plate with excellent low-frequency sound insulation performance is designed to meet the low-frequency sound insulation requirements of different environments. Summary of the Invention

[0004] The purpose of the present application is to provide a low-frequency thin and light sound insulation structure, which can be used to manufacture sound insulation walls or surfaces for facilities such as manufacturing workshops, ultra-clean rooms, traffic sound insulation barriers, and indoor buildings, so as to achieve the attenuation and blocking of noise and improve the living and working environment of people.

[0005] To achieve the above purpose, the present application provides the following technical solution: A low-frequency thin and light sound insulation structure, comprising a bottom plate, a partition plate, a perforated plate, and a porous material arranged in sequence from bottom to top. The partition plate is arranged in a circular structure. The porous material is located in the installation cavity surrounded by the bottom plate, the partition plate, and the perforated plate. The bottom plate, the partition plate, the perforated plate, and the porous material are combined together to achieve low-frequency sound insulation.

[0006] As a preferred implementation manner in this embodiment, the porous material is made of fiber cotton or foam material.

[0007] As a preferred implementation manner in this embodiment, the porous material is a corrugated perforated plate.

[0008] As a preferred implementation manner in this embodiment, the bottom plate and the perforated plate are made of one or more of wood board, bamboo board, flame-retardant PLA, and ABS material.

[0009] A method for calculating the thickness of a low-frequency, thin and lightweight sound insulation structure, comprising the following steps:

[0010] S1: Evaluation of ambient noise. According to the actual situation of the ambient noise, measure the noise level and its concentrated frequency range in the noise environment, determine the noise level to be reduced and its frequency range, and obtain the design requirements;

[0011] S2: Divide the sound insulation structure into five layers, with impedance ratios Z1, Z2, Z3, Z4, and Z5 respectively. t1, t2, and t3 are the thicknesses of the micro-perforated plate, porous material, and bottom plate respectively;

[0012] The first layer is air. Assuming the density of air is ρ1 and the sound speed is c1, the acoustic impedance can be expressed as:

[0013] Z1 = ρ1c1 (1)

[0014] The second layer is the micro-perforated plate, and the acoustic impedance can be expressed as:

[0015]

[0016] In Equation (2), η is the viscous system, t1 is the thickness of the micro-perforated plate, d is the diameter of the small holes, and p is the perforation rate.

[0017] The third layer is the porous material, and the complex impedance Z3 can be expressed as:

[0018]

[0019] The fourth layer is, assuming the density of the sound insulation board is ρ4 and the speed of sound propagation through the board is c4, the acoustic impedance can be expressed as:

[0020] Z4 = ρ4c4 (6)

[0021] The fifth layer is air. Assuming the density of air is ρ4 and the sound speed is c4, the acoustic impedance can be expressed as:

[0022] Z5 = ρ5c5 (7)

[0023] p1i is the sound pressure of the incident noise and can be expressed as:

[0024]

[0025] p5i is the sound pressure of the incident noise and can be expressed as:

[0026]

[0027] The wave equation of noise in the medium is:

[0028]

[0029] S3: According to the boundary conditions of continuous vibration of the normal particle sound velocity and continuous sound pressure, substituting equations (1)-(9) into equation (10), the transmission coefficient of this structure can be obtained as follows:

[0030]

[0031] The sound insulation amount of this structure is:

[0032]

[0033] Equation (12) is for this structure including one to five layers of structures and performance parameters, and can be used to calculate the sound insulation amount of structures with different thickness dimensions. The size of the sound insulation amount is only related to the thickness and has nothing to do with the length and width. Therefore, the size of the unit length can be evenly divided according to the size of the sound insulation area for easy installation.

[0034] An application of a low-frequency thin and light sound insulation structure, which is used to make a sound insulation barrier, a sound insulation wall or a unit structure and is arranged on the wall, can greatly attenuate the transmission of indoor noise to the outside and also greatly attenuate the transmission of outdoor noise to the inside.

[0035] In summary, the technical effects and advantages of the present invention:

[0036] The present invention absorbs the sound insulation characteristics of thin plate resonance, porous materials and micro-perforated plate + cavity, effectively combines the three, and realizes bilateral low-frequency sound insulation according to the environmental sound insulation requirements. The sound insulation performance on the thin plate side is better than that on the perforated plate side, and the sound insulation amount is higher than 30 dB, with excellent low-frequency sound insulation performance. Description of the Drawings

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for description in the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0039] Figure 2 It is Figure 1 the explosion diagram in

[0040] Figure 3 It is a schematic diagram of the corrugated perforated plate structure;

[0041] Figure 4 It is the sound insulation principle diagram provided by the present invention;

[0042] Figure 5 The sound insulation quantity test curve graph is provided for the present invention.

[0043] In the figure: 1. bottom plate; 2. partition board; 3. perforated plate; 4. porous material. Specific implementation manners

[0044] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0045] Embodiment: A low-frequency thin and light sound insulation structure includes a bottom plate 1, a partition board 2, a perforated plate 3, and a porous material 4 arranged in sequence from bottom to top. The partition board 2 is arranged in a loop structure. The porous material 4 is located in the installation cavity surrounded by the bottom plate 1, the partition board 2, and the perforated plate 3. The bottom plate 1, the partition board 2, the perforated plate 3, and the porous material 4 are combined together to achieve low-frequency sound insulation.

[0046] As a preferred implementation manner in this embodiment, the porous material 4 is made of fiber cotton or foam material.

[0047] As a preferred implementation manner in this embodiment, the porous material 4 is a corrugated perforated plate.

[0048] As a preferred implementation manner in this embodiment, the bottom plate 1 and the perforated plate 3 are made of one or more of wood board, bamboo board, flame-retardant PLA, and ABS material.

[0049] This sound insulation device uses bamboo board, wood board, PLA, and ABS as thin plates, perforated plates, and partition boards. Their densities are all less than 1 g / cm3. The thickness of the perforated plate is about 5 - 12 mm, and the thickness of the bottom plate is about 0.5 - 1 mm. The cavity is filled with a porous material, which can achieve a lightweight design, and has a small thickness size, occupies a small space, and is convenient for installation and use.

[0050] According to the sound insulation requirements of different environments, by changing the thickness of the bottom plate 1, the thickness of the perforated plate 3, the aperture and the distribution of the holes, and the thickness of the porous material 4, it can be used in noise reduction environments of different frequency bands. This structure can be made into a sound insulation barrier, a sound insulation wall, or a sound insulation unit structure, and arranged on the wall, which can greatly attenuate the transmission of indoor noise to the outside and also greatly attenuate the transmission of outdoor noise to the inside, improving the quality of people's work and life.

[0051] The present invention absorbs the sound insulation characteristics of micro-perforated plates + cavities, thin plate resonance, and porous materials. The three are effectively combined together to obtain a vibration isolation device with a thin and light structure and excellent sound insulation effect. The remarkable advantages are as follows:

[0052] (1) The present invention absorbs the sound insulation characteristics of thin plate resonance, porous materials, and micro-perforated plates + chambers, effectively combines the three, and realizes bilateral low-frequency sound insulation according to the environmental sound insulation requirements. The sound insulation performance on the thin plate side is better than that on the perforated plate side, and the sound insulation amount is higher than 30 dB, with excellent low-frequency sound insulation performance.

[0053] (2) This sound insulation device can be designed as a modular unit and attached indoors, or designed according to the shape of the sound insulation space, or designed as a sound insulation wall. The structural design is flexible and convenient for use;

[0054] (3) This sound insulation device uses bamboo boards, wooden boards, PLA, and ABS as thin plates, perforated plates, and partition boards, with a density less than 1 g / cm3. The chamber is filled with porous materials, which can achieve lightweight design, small thickness size, small occupied space, and is convenient for installation and use.

[0055] A thickness calculation method for a low-frequency thin and lightweight sound insulation structure includes the following steps.

[0056] S1: Evaluation of environmental noise. According to the actual situation of environmental noise, measure the noise level and its concentrated frequency range in the noise environment, determine the noise level to be reduced and its frequency range, and obtain the design requirements;

[0057] S2: Divide the sound insulation structure into five layers, with impedance ratios Z1, Z2, Z3, Z4, and Z5 respectively. t1, t2, and t3 are the thicknesses of the micro-perforated plate, porous material, and bottom plate respectively;

[0058] The first layer is air. Assuming the density of air is ρ1 and the sound speed is c1, the acoustic impedance can be expressed as:

[0059] Z1 = ρ1 c1 (1)

[0060] The second layer is the micro-perforated plate, and the acoustic impedance can be expressed as:

[0061]

[0062] In formula (2), η is the viscous system, t1 is the thickness of the micro-perforated plate, d is the diameter of the small hole, and p is the perforation rate.

[0063] The third layer is the porous material, and the complex impedance Z3 can be expressed as:

[0064]

[0065] The fourth layer is, assuming the density of the sound insulation board is ρ4 and the speed of sound propagation through the board is c4, the acoustic impedance can be expressed as:

[0066] Z4 = ρ4 c4 (6)

[0067] The fifth layer is air. Assuming the density of air is ρ4 and the speed of sound is c4, the acoustic impedance can be expressed as:

[0068] Z5 = ρ5 c5 (7)

[0069] In Figure 4 p1i is the sound pressure of the incident noise and can be expressed as:

[0070]

[0071] In Figure 4 p5i is the sound pressure of the incident noise and can be expressed as:

[0072]

[0073] The wave equation of noise in the medium is:

[0074]

[0075] S3: According to the boundary conditions of continuous normal particle velocity vibration and continuous sound pressure, substituting equations (1)-(9) into equation (10), the transmission coefficient of this structure can be obtained as:

[0076]

[0077] The sound insulation quantity of this structure is:

[0078]

[0079] Equation (12) is for this structure including the structures and performance parameters of the first to fifth layers, and can be used to calculate the sound insulation quantity of structures with different thickness dimensions. The size of the sound insulation quantity is only related to the thickness and has nothing to do with the length and width. Therefore, the size of the unit length can be evenly divided according to the size of the sound insulation area for easy installation.

[0080] Sound insulation performance test and evaluation of the sound insulation device: (First, measure the noise level and its concentrated frequency range in the noise environment, determine the noise level to be reduced and its frequency range. According to the sound insulation principle, design Figure 1 the thicknesses of the perforated plate, bottom plate and porous material in Figure 5 process the perforated plate, partition plate and bottom plate, assemble them in series from top to bottom, and fill the cavity with porous material to form a sound insulation unit of the present invention). Assume that the noise frequency range of a certain environment is 64 Hz - 1000 Hz, and the lowest noise transmission loss is 30 dB. Using the structure of the present invention, the designed total thickness is 60 mm. Select the PLA flame-retardant material to process the test piece. When the noise is incident from the perforated plate side 3 and the bottom plate 1 side, the measured noise transmission loss curve is as shown in the appendix, the test structure shows that when the noise is incident from the side of the perforated plate 3, the lowest sound transmission loss is 35 dB at 325 Hz, and the average sound transmission loss is 40 dB; when the noise is incident from the side of the bottom plate 1, at 375 Hz, the lowest sound transmission loss is 41 dB, and the average sound transmission loss is 52 dB. The experimental test proves that excellent sound insulation performance can be obtained when the noise is incident from both sides respectively. When the noise is introduced from the side without the perforated plate 3, the sound insulation performance is better than that of the perforated side.

[0081] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-frequency thin and light sound insulation structure, characterized in that, It includes a bottom plate (1), a partition plate (2), a perforated plate (3), and a porous material (4) arranged successively from bottom to top. The partition plate (2) is arranged in a loop structure. The porous material (4) is located in the installation cavity surrounded by the bottom plate (1), the partition plate (2), and the perforated plate (3). The bottom plate (1), the partition plate (2), the perforated plate (3), and the porous material (4) are combined together to achieve low-frequency sound insulation.

2. The low-frequency thin and light sound insulation structure according to claim 1, characterized in that: The porous material (4) is made of fiber cotton or foam material.

3. The low-frequency thin and light sound insulation structure according to claim 1, characterized in that: The porous material (4) is a corrugated perforated plate.

4. The low-frequency thin and light sound insulation structure according to claim 1, characterized in that: The bottom plate (1) and the perforated plate (3) are made of one or more of wood board, bamboo board, flame-retardant PLA, and ABS material.

5. The thickness calculation method of a low-frequency thin and light sound insulation structure according to claim 1, characterized in that: It includes the following steps S1: Evaluation of ambient noise. According to the actual situation of the ambient noise, measure the noise volume and its concentrated frequency range in the noise environment, determine the noise volume to be reduced and its frequency range, and obtain the design requirements. S2: Divide the sound insulation structure into five layers, and their impedance ratios are Z1, Z2, Z3, Z4, and Z5 respectively. t1, t2, and t3 are the thicknesses of the micro-perforated plate, the porous material, and the bottom plate respectively. The first layer is air. Assuming the density of air is ρ1 and the sound speed is c1, the acoustic impedance can be expressed as: Z1 = ρ1c1 (1) The second layer is the micro-perforated plate, and the acoustic impedance can be expressed as: In formula (2), η is the viscous system, t1 is the thickness of the micro-perforated plate, d is the diameter of the small hole, and p is the perforation rate. The third layer is the porous material, and the complex impedance Z3 can be expressed as: The fourth layer is, assuming the density of the sound insulation board is ρ4 and the speed of the board transmitting noise is c4, the acoustic impedance can be expressed as: Z4 = ρ4c4 (6) The fifth layer is air. Assuming the density of air is ρ4 and the sound speed is c4, the acoustic impedance can be expressed as: Z5 = ρ5c5 (7) p1i is the sound pressure of the incident noise and can be expressed as: p5i is the sound pressure of the incident noise and can be expressed as: The wave equation of the noise in the medium is: S3: According to the boundary conditions of the continuous normal particle sound speed vibration and the continuous sound pressure, substitute equations (1)-(9) into equation (10), and the transmission coefficient of this structure can be obtained as: The sound insulation amount of this structure is: Equation (12) is the structure and performance parameters of this structure including one to five layers, which can be used to calculate the sound insulation amount of structures with different thickness dimensions. The size of the sound insulation amount is only related to the thickness and has nothing to do with the length and width. Therefore, the size of the unit length can be evenly divided according to the size of the sound insulation area as long as it is convenient for installation.

6. Application of a low-frequency thin and light sound insulation structure according to claim 1, characterized in that: This sound insulation structure is used to make sound insulation barriers, sound insulation walls or unit structures, and arranged on the wall, which can greatly attenuate the transmission of indoor noise to the outside and also greatly attenuate the transmission of outdoor noise to the inside.

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