A low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section

Abstract

This invention relates to the field of sound-absorbing structure technology, and more particularly to a multi-layer abrupt cross-section perforated plate low-frequency sound-absorbing structure, comprising a small-diameter perforated plate, a large-diameter perforated plate, small perforations, and large perforations. The large-diameter perforated plate is cylindrical. The through holes in the abrupt cross-section perforated plate are all fixedly connected to the outer wall of a large-diameter perforated plate. The large-diameter perforated plate has a through-hole. The small-diameter perforated plate is fixedly connected to the surface of the large-diameter perforated plate away from the rigid wall. The small-diameter perforated plate has a coaxial through-hole. The small and large perforations on each of the abrupt cross-section perforated devices are interconnected. This invention solves the problem of poor sound absorption performance of porous sound-absorbing materials for low-frequency noise in the prior art. Through the combination of the multi-layer abrupt cross-section perforated plate structure, the sound-absorbing device's ability to absorb and dissipate low-frequency noise is improved.

Description

Technical Field

[0001] This invention relates to the field of sound-absorbing structure technology, and in particular to a low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section. Background Technology

[0002] With the development of the economy and society, noise pollution has become increasingly serious. Various diseases caused by noise are increasing day by day, eroding people's health. Therefore, noise pollution has become the world's fourth largest pollution after air pollution, water pollution and solid waste pollution, becoming an environmental hazard that harms people's lives, work and even physical and mental health. As a result, the requirements for sound insulation in buildings are increasing.

[0003] There are many types of sound-absorbing materials, which can be divided into two main categories according to their material structure: porous sound-absorbing materials and resonant sound-absorbing structures. Commonly used porous sound-absorbing materials have better sound absorption effects in the mid-to-high frequency range, but poorer sound absorption performance in the low frequency range. Summary of the Invention

[0004] This application provides a multi-layer abrupt cross-section perforated plate low-frequency sound-absorbing structure, which solves the problem of poor sound absorption performance of porous sound-absorbing materials for low-frequency noise in the prior art. By combining the multi-layer abrupt cross-section perforated plate structure, the ability of the sound-absorbing device to absorb and dissipate low-frequency noise is improved.

[0005] This application provides a multi-layer abrupt cross-section perforated plate low-frequency sound-absorbing structure, including an abrupt cross-section perforated plate, a rigid wall, and a variable cross-section perforation device;

[0006] The perforated plate with abrupt cross-section has a cubic structure.

[0007] A rigid wall is movably connected below the perforated plate with abrupt cross-section, and the rigid wall has the same shape as the perforated plate with abrupt cross-section.

[0008] The abruptly changed cross-section perforated plate has several through holes, and each through hole is fixedly connected to a abruptly changed cross-section perforated device.

[0009] Each of the aforementioned variable cross-section perforation devices includes a small-diameter perforation plate, a large-diameter perforation plate, a small perforation, and a large perforation;

[0010] The large-diameter perforated plate is cylindrical, and the through holes of the perforated plate with abrupt cross-section are all fixedly connected to a large-diameter perforated plate, with the large-diameter perforated plate having a large through hole.

[0011] The large-diameter perforated plate is fixedly connected to the small-diameter perforated plate on the side away from the rigid wall, and the small-diameter perforated plate is coaxially perforated through a small perforation.

[0012] The small and large perforations on each of the variable cross-section perforation devices are interconnected.

[0013] Furthermore, the low-frequency sound-absorbing structure can be composed of multiple layers of perforated plates with abrupt cross-sections. By controlling the number of layers of perforated plates with abrupt cross-sections, the resonant frequency of the structure can be changed, thereby absorbing noise of different frequencies.

[0014] Furthermore, a cavity is formed between the abruptly cross-section perforated plate and the rigid wall.

[0015] Furthermore, in the low-frequency sound-absorbing structure spliced ​​with two layers of perforated plates with abrupt cross sections, the volume of the small perforation is 0.27% of the volume of the small-diameter perforated plate, the thickness of the small-diameter perforated plate is 1mm, and the diameter of the small perforation is 1.5mm.

[0016] Furthermore, in the low-frequency sound-absorbing structure spliced ​​with two layers of abruptly changed cross-section perforated plates, the volume of the large perforation is 0.27% of the volume of the large-diameter perforated plate, the thickness of the large-diameter perforated plate is 1mm, the diameter of the large perforation is 4mm, and when there are two layers of abruptly changed cross-section perforated plates, the thickness of the cavity is set to 39mm.

[0017] Furthermore, in the low-frequency sound-absorbing structure spliced ​​from three layers of perforated plates with abrupt cross-sections, the volume of the small perforation is 0.25% of the volume of the small-diameter perforated plate, the thickness of the small-diameter perforated plate is 1mm, and the diameter of the small perforation is 1.5mm.

[0018] Furthermore, in the low-frequency sound-absorbing structure spliced ​​from three layers of perforated plates with abrupt cross sections, the volume of the large perforation is 0.27% of the volume of the large-diameter perforated plate, the thickness of the large-diameter perforated plate is 1mm, the diameter of the large perforation is 4mm, and when the number of layers of perforated plates with abrupt cross sections is three, the thickness of the cavity is set to 25mm.

[0019] Furthermore, the variable cross-section perforation device also includes a flared opening;

[0020] Each of the large-diameter perforated plates has a downward-facing flared opening on the side near the rigid wall.

[0021] In each of the variable cross-section perforation devices, the small perforations and large perforations are interconnected to form a threaded flow channel;

[0022] The flared opening is interconnected with the small and large perforations to form a spiral flow channel.

[0023] Further, such as Figure 6 , Figure 7 As shown, the multi-layer abrupt cross-section perforated plate low-frequency sound-absorbing structure also includes a variable cross-section perforation device group;

[0024] Each of the aforementioned variable cross-section perforation devices includes a threaded flow channel composed of two small perforations and a large perforation. The two sets of flow channels composed of small perforations and large perforations are threadedly wound and connected to the flared mouth.

[0025] In the low-frequency sound-absorbing structure spliced ​​with two layers of abrupt cross-section perforated plates, the multiple variable cross-section perforated device groups fixedly connected to the abrupt cross-section perforated plates close to the rigid wall are divided into several groups. Each variable cross-section perforated device group consists of multiple variable cross-section perforated devices, and the variable cross-section perforated devices in each variable cross-section perforated device group are arranged in a cross shape.

[0026] In a low-frequency sound-absorbing structure spliced ​​from two layers of abruptly changed cross-section perforated plates, each horn-shaped opening in the abruptly changed cross-section perforated plate far from the rigid wall corresponds to the center point of a set of variable cross-section perforated devices in the lower abruptly changed cross-section perforated plate.

[0027] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0028] Firstly, when sound passes through a multi-layer perforated plate with abrupt cross-section, the channel formed by several small and large perforations on the perforated plate absorbs and vibrates the low-frequency noise, causing the low-frequency noise to resonate with the two layers of perforated plates with abrupt cross-section, thereby absorbing and consuming noise of different frequencies.

[0029] Secondly, the overall shape of the flow channel formed by the small and large perforations is changed to a spiral shape, which makes the path of noise through the variable cross-section perforation device longer, thereby consuming more sound energy. After the noise enters the horn mouth through the flow channel formed by the small and large perforations, it will gradually expand along the inner wall of the horn mouth and enter more variable cross-section perforation devices on the surface of the next layer of abrupt cross-section perforated plate, thereby further improving the sound absorption effect of the abrupt cross-section perforated plate.

[0030] Third, each of the aforementioned variable cross-section perforated devices includes a spiral flow channel composed of two small perforations and a large perforation. The two sets of flow channels composed of small and large perforations are spirally wound. When the sound passes through the two spirally wound flow channels, it will affect each other and vibrate. Each horn opening of the abrupt cross-section perforated plate away from the rigid wall corresponds to the center of a group of variable cross-section perforated devices in the abrupt cross-section perforated plate close to the rigid wall. This allows the noise transmitted from a single horn opening on the upper abrupt cross-section perforated plate to be absorbed and consumed by multiple abrupt cross-section perforated plates in the lower abrupt cross-section perforated device group, further improving the working efficiency of the low-frequency sound-absorbing structure. Attached Figure Description

[0031] Figure 1 This invention presents a two-layer perforated plate structure with abrupt cross-section.

[0032] Figure 2 This invention relates to a three-layer perforated plate structure with abrupt cross-section.

[0033] Figure 3 This is a cross-sectional view of the abrupt cross-section perforation device proposed in this invention;

[0034] Figure 4 This invention relates to an acoustic system with a multi-layer abrupt cross-section perforated plate sound-absorbing structure.

[0035] Figure 5 This is a cross-sectional view of the abrupt cross-section perforation device in Embodiment 2 of the present invention;

[0036] Figure 6 The three-layer perforated plate structure with abrupt cross-section proposed in Embodiment 3 of this invention;

[0037] Figure 7 This is a cross-sectional view of the abrupt cross-section perforation device in Embodiment 3 of the present invention.

[0038] In the figure: 100, abrupt cross-section perforated plate; 200, rigid wall; 300, variable cross-section perforation device; 310, small-diameter perforated plate; 320, large-diameter perforated plate; 330, small perforation; 340, large perforation; 350, bell mouth; 400, cavity; 500, variable cross-section perforation device assembly. Detailed Implementation

[0039] To facilitate understanding of the present invention, a more complete description of this application will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to enable a more thorough and complete understanding of the disclosure of the present invention.

[0040] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] Example 1

[0043] like Figures 1-4 As shown, the present application proposes a multi-layer abrupt cross-section perforated plate low-frequency sound absorption structure, including an abrupt cross-section perforated plate 100, a rigid wall 200, and a variable cross-section perforation device 300.

[0044] The abrupt cross-section perforated plate 100 has a cubic structure;

[0045] A rigid wall 200 is movably connected below the abrupt cross-section perforated plate 100, and the rigid wall 200 has the same shape as the abrupt cross-section perforated plate 100.

[0046] The abrupt cross-section perforated plate 100 has several through holes, and each through hole is fixedly connected to a variable cross-section perforated device 300.

[0047] Each of the aforementioned variable cross-section perforation devices 300 includes a small-diameter perforated plate 310, a large-diameter perforated plate 320, a small perforation 330, and a large perforation 340;

[0048] The large-diameter perforated plate 320 is cylindrical. The through holes opened in the abrupt cross-section perforated plate 100 are all fixedly connected to the outer wall of the large-diameter perforated plate 320. The large-diameter perforated plate 320 has a large perforation 340 through it.

[0049] The large-diameter perforated plate 320 is fixedly connected to the small-diameter perforated plate 310 on the surface away from the rigid wall 200, and the small-diameter perforated plate 310 is coaxially perforated with a small perforation 330.

[0050] The small perforations 330 and large perforations 340 on each of the variable cross-section perforation devices 300 are interconnected.

[0051] Furthermore, the low-frequency sound-absorbing structure can be composed of multiple layers of perforated plates 100 with abrupt cross sections. By controlling the number of layers of perforated plates 100 with abrupt cross sections, the resonant frequency of the structure can be changed, thereby absorbing noise of different frequencies.

[0052] Furthermore, a cavity 400 is formed between the abruptly cross-section perforated plate 100 and the rigid wall 200.

[0053] Furthermore, in the low-frequency sound-absorbing structure spliced ​​from two layers of abruptly cross-section perforated plates 100, the volume ratio of small perforation 330 to small aperture perforated plate 310 is 0.27%, the thickness of small aperture perforated plate 310 is 1mm, and the aperture of small perforation 330 is 1.5mm.

[0054] Furthermore, in the low-frequency sound-absorbing structure spliced ​​from two layers of abruptly changed cross-section perforated plates 100, the volume ratio of the large perforation 340 to the large aperture perforated plate 320 is 0.27%, the thickness of the large aperture perforated plate 320 is 1mm, the aperture of the large perforation 340 is 4mm, and when the number of abruptly changed cross-section perforated plates 100 is two, the thickness of the cavity 400 is set to 39mm.

[0055] Furthermore, in the low-frequency sound-absorbing structure formed by splicing three layers of abruptly cross-section perforated plates 100, the volume ratio of small perforation 330 to small aperture perforated plate 310 is 0.25%, the thickness of small aperture perforated plate 310 is 1mm, and the aperture of small perforation 330 is 1.5mm.

[0056] Furthermore, in the low-frequency sound-absorbing structure formed by splicing three layers of abruptly changed cross-section perforated plates 100, the volume ratio of large perforation 340 to large aperture perforated plate 320 is 0.27%, the thickness of large aperture perforated plate 320 is 1mm, the aperture of large perforation 340 is 4mm, and when the number of layers of abruptly changed cross-section perforated plates 100 is three, the thickness of cavity 400 is set to 25mm.

[0057] Specific implementation: When sound passes through the multi-layer abrupt cross-section perforated plate 100, the channel formed by several small perforations 330 and large perforations 340 on the abrupt cross-section perforated plate 100 will absorb and vibrate the low-frequency noise, causing the low-frequency noise and the two layers of abrupt cross-section perforated plate 100 to resonate, thereby absorbing and consuming noise of different frequencies.

[0058] Example 2

[0059] In order to further improve the sound absorption effect of the multi-layer abrupt cross-section perforated plate 100, Example 2 makes further improvements to Example 1.

[0060] like Figure 5 As shown, the variable cross-section perforation device 300 also includes a flared opening 350;

[0061] Each of the large-diameter perforated plates 320 has a downward-facing flared opening 350 on the side near the rigid wall 200.

[0062] In each of the variable cross-section perforation devices 300, the small perforation 330 and the large perforation 340 are interconnected to form a threaded flow channel;

[0063] The flared opening 350 is interconnected with the small perforation 330 and the large perforation 340 to form a threaded flow channel.

[0064] By changing the overall shape of the flow channel formed by the small perforation 330 and the large perforation 340 to a spiral shape, the path of noise through the variable cross-section perforation device 300 is lengthened, thereby consuming more sound energy. After the noise passes through the flow channel formed by the small perforation 330 and the large perforation 340 and enters the horn mouth 350, it will gradually expand along the inner wall of the horn mouth 350 and enter more variable cross-section perforation devices 300 on the surface of the next layer of abrupt cross-section perforated plate 100, thereby further improving the sound absorption effect of the abrupt cross-section perforated plate 100.

[0065] Example 3

[0066] In order to further improve the energy absorption efficiency of a single variable cross-section perforation device 300, Embodiment 3 makes further improvements to Embodiment 2.

[0067] like Figure 6 , Figure 7 As shown, the multi-layer abrupt cross-section perforated plate low-frequency sound-absorbing structure also includes a variable cross-section perforated device group 500.

[0068] Each of the variable cross-section perforation devices 300 includes a threaded flow channel composed of two small perforations 330 and a large perforation 340. The two sets of flow channels composed of small perforations 330 and large perforations 340 are threaded together and communicate with the flared mouth 350.

[0069] In the low-frequency sound-absorbing structure spliced ​​by two layers of abrupt cross-section perforated plates 100, the abrupt cross-section perforated plates 100 close to the rigid wall 200 are fixedly connected to multiple variable cross-section perforated device groups 500, which are divided into several groups. Each variable cross-section perforated device group 500 consists of multiple variable cross-section perforated devices 300, and the variable cross-section perforated devices 300 in each variable cross-section perforated device group 500 are arranged in a cross shape.

[0070] In the low-frequency sound-absorbing structure spliced ​​by two layers of abrupt cross-section perforated plates 100, each horn opening 350 of the abrupt cross-section perforated plate 100 away from the rigid wall 200 corresponds to the center point of a group of variable cross-section perforated devices 500 in the lower abrupt cross-section perforated plate 100.

[0071] Each of the aforementioned variable cross-section perforated devices 300 includes a spiral flow channel composed of two small perforations 330 and a large perforation 340. The two sets of flow channels composed of small perforations 330 and large perforations 340 are spirally intertwined. When sound passes through the two spirally intertwined flow channels, it will affect each other and vibrate. Each horn opening 350 of the abrupt cross-section perforated plate 100 away from the rigid wall 200 corresponds to the center of a group of variable cross-section perforated devices 500 in the abrupt cross-section perforated plate 100 close to the rigid wall 200. This allows the noise transmitted from a single horn opening 350 on the upper abrupt cross-section perforated plate 100 to be absorbed and consumed by multiple abrupt cross-section perforated plates 100 in the lower variable cross-section perforated device group 500, further improving the working efficiency of the low-frequency sound-absorbing structure.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-layer perforated plate low-frequency sound-absorbing structure with abrupt cross-section, comprising a perforated plate with abrupt cross-section (100), a rigid wall (200), and a perforated device with a variable cross-section (300). The perforated plate (100) with abrupt cross-section has a cubic structure; A rigid wall (200) is movably connected below the abrupt cross-section perforated plate (100), and the rigid wall (200) has the same shape as the abrupt cross-section perforated plate (100); The abruptly changed cross-section perforated plate (100) has several through holes, and each through hole is fixedly connected to a variable cross-section perforated device (300); characterized in that, Each of the aforementioned variable cross-section perforation devices (300) includes a small-diameter perforation plate (310), a large-diameter perforation plate (320), a small perforation (330), and a large perforation (340). The large-diameter perforated plate (320) is cylindrical. The through holes of the abrupt cross-section perforated plate (100) are all fixedly connected to a large-diameter perforated plate (320), and the large-diameter perforated plate (320) has a large perforation (340) through it. The large-diameter perforated plate (320) is fixedly connected to the small-diameter perforated plate (310) on the side away from the rigid wall (200), and the small-diameter perforated plate (310) is coaxially perforated with a small perforation (330). The small perforations (330) and large perforations (340) on each of the aforementioned variable cross-section perforation devices (300) are interconnected; The low-frequency sound-absorbing structure is composed of multiple layers of perforated plates (100) with abrupt cross-sections spliced ​​together; Each of the aforementioned variable cross-section perforation devices (300) includes a threaded flow channel composed of two small perforations (330) and a large perforation (340). The flow channels composed of the two sets of small perforations (330) and large perforations (340) are threaded together and communicate with the flared mouth (350). In the low-frequency sound-absorbing structure spliced ​​by two layers of abrupt cross-section perforated plates (100), the abrupt cross-section perforated plates (100) close to the rigid wall (200) are fixedly connected to multiple variable cross-section perforated device groups (500), which are divided into several groups. Each variable cross-section perforated device group (500) consists of multiple variable cross-section perforated devices (300), and the variable cross-section perforated devices (300) in each variable cross-section perforated device group (500) are arranged in a cross shape. In the low-frequency sound-absorbing structure spliced ​​by two layers of abrupt cross-section perforated plates (100), each horn opening (350) of the abrupt cross-section perforated plate (100) far from the rigid wall (200) corresponds to the center point of a set of variable cross-section perforated devices (300) in the lower abrupt cross-section perforated plate (100).

2. The low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section as described in claim 1, characterized in that, The variable cross-section perforation device (300) also includes a flared opening (350); Each of the large-diameter perforated plates (320) has a downward-facing flared opening (350) on the side close to the rigid wall (200). In each of the variable cross-section perforation devices (300), the small perforations (330) and the large perforations (340) are interconnected to form a threaded flow channel; The flared opening (350) is interconnected with the small perforation (330) and the large perforation (340) to form a threaded flow channel.

3. The low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section as described in claim 1, characterized in that, A cavity (400) is formed between the abrupt cross-section perforated plate (100) and the rigid wall (200).

4. The low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section as described in claim 1, characterized in that, In the low-frequency sound-absorbing structure spliced ​​from two layers of abruptly cross-section perforated plates (100), the volume of the small perforation (330) is 0.27% of the volume of the small aperture perforated plate (310), the thickness of the small aperture perforated plate (310) is 1mm, and the aperture of the small perforation (330) is 1.5mm.

5. The low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section as described in claim 1, characterized in that, In the low-frequency sound-absorbing structure spliced ​​from two layers of abruptly changed cross-section perforated plates (100), the volume of the large perforation (340) is 0.27% of the volume of the large-diameter perforated plate (320), the thickness of the large-diameter perforated plate (320) is 1mm, the diameter of the large perforation (340) is 4mm, and when the number of layers of abruptly changed cross-section perforated plates (100) is two, the thickness of the cavity (400) is set to 39mm.

6. The low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section as described in claim 1, characterized in that, In the low-frequency sound-absorbing structure formed by splicing three layers of abrupt cross-section perforated plates (100), the volume of the small perforation (330) is 0.25% of the volume of the small aperture perforated plate (310), the thickness of the small aperture perforated plate (310) is 1mm, and the aperture of the small perforation (330) is 1.5mm.

7. The low-frequency sound-absorbing structure of a multi-layer perforated plate with abrupt cross-section as described in claim 1, characterized in that, In the low-frequency sound-absorbing structure spliced ​​from three layers of abruptly changed cross-section perforated plates (100), the volume of the large perforation (340) is 0.27% of the volume of the large-diameter perforated plate (320), the thickness of the large-diameter perforated plate (320) is 1mm, the diameter of the large perforation (340) is 4mm, and when the number of layers of the abruptly changed cross-section perforated plate (100) is three, the thickness of the cavity (400) is 25mm.

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