Anti-diffraction device and sound barrier

Abstract

The utility model discloses an anti-diffraction device and a sound barrier, and relates to the technical field of sound insulation, and the anti-diffraction device comprises a housing and a sound absorption unit. The shell comprises a first side plate, a second side plate and a top plate, wherein the first side plate and the second side plate are oppositely arranged, the top plate is connected to the top of the first side plate and the top of the second side plate, and the first side plate and the second side plate are each provided with one or more through holes. The sound absorption unit is arranged in a cavity formed among the first side plate, the second side plate and the top plate, and the sound absorption unit is made of a sound absorption material. On one hand, the top of the sound barrier is relatively soft, impedance of the top can be reduced, and compared with a traditional sound barrier with a hard top, sound absorption can be achieved on the top, and the volume of sound diffracted to a protection area from the top is reduced. And on the other hand, the two sides of the sound absorption unit are communicated, so that the sound absorption effect of a lower frequency band can be effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to sound insulation technical field especially, relates to a kind of anti-diffraction device and sound barrier. BACKGROUND

[0002] Sound barrier 10 is a sound insulation noise reduction device, reference Figure 1 It is arranged between sound source 11 and protection area 12, can block the sound propagation of sound source 11 to protection area 12, to reduce the sound pressure level at protection area 12, reduce the influence of the sound of sound source 11 at protection area 12.

[0003] For example, sound barrier 10 can be arranged on both sides of highway, highway, elevated composite road and the like to reduce the influence of noise generated by vehicles on the external area of highway.

[0004] For example, sound barrier 10 can be used indoors to divide a large space into several small rooms and reduce the influence of sound between rooms.

[0005] At present, sound barrier is mostly made of concrete, metal, plastic, glass and other materials. Since the sound barrier material is very "hard" relative to air, it can reflect sound waves, thereby achieving sound insulation effect. The top of the sound barrier is generally a hard structure, which can be vertical or curved towards the sound source direction, mainly reducing the conduction of noise to the protection area 12 by reflection.

[0006] However, diffraction of sound waves is also a major factor affecting the performance of sound barrier. Low-frequency sound waves have weak directivity, large wavelength and even comparable to the sound barrier itself, with strong diffraction performance. Therefore, low-frequency sound waves can bypass the sound barrier and propagate, reducing the sound insulation performance of the sound barrier. In general, increasing the height of the sound barrier can reduce the influence of low-frequency noise diffraction, but undoubtedly increases the additional construction cost and affects the overall aesthetic performance.

[0007] Therefore, the sound insulation effect of the sound barrier still needs to be improved.

[0008] The above content is only used to help understand the technical solutions of the present application and does not constitute an acknowledgement of the above as prior art. UTILITY MODEL CONTENT

[0009] The utility model aims at providing an anti-diffraction device and sound barrier to improve the sound insulation effect.

[0010] To achieve the above utility model purpose, in the first aspect, the utility model provides an anti-diffraction device, comprising:

[0011] The housing comprises a first side panel and a second side panel arranged opposite to each other, and a top panel connected to the top of the first side panel and the second side panel, wherein the first side panel and the second side panel are each provided with one or more through holes; and

[0012] The sound absorbing unit is arranged in a cavity formed between the first side plate, the second side plate and the top plate, and the sound absorbing unit is made of sound absorbing material.

[0013] In a second aspect, the present invention provides an anti-diffraction device, comprising:

[0014] The housing comprises a first side panel and a second side panel arranged opposite to each other and a top panel connected to the top of the first side panel and the second side panel; and

[0015] a sound absorbing unit, disposed in a cavity formed between the first side panel, the second side panel, and the top panel;

[0016] The shell and the sound absorbing unit are both made of sound absorbing materials.

[0017] In a third aspect, the present invention proposes a sound barrier comprising the anti-diffraction device described above.

[0018] Compared with the prior art, the present invention has the following beneficial effects: the anti-diffraction device of the present invention includes a shell and a sound absorbing unit, the shell includes a first side panel and a second side panel arranged opposite to each other and a top panel connected to the top of the first side panel and the second side panel; the sound absorbing unit is arranged in a cavity formed between the first side panel, the second side panel and the top panel, and the sound absorbing unit is made of sound absorbing material. Sound can enter the interior of the shell through the side panels and be absorbed by the sound absorbing unit. On the one hand, the top of the sound barrier is relatively soft, which can reduce the impedance of the top. Compared with the traditional sound barrier with a hard top, it can absorb sound at the top and reduce the size of the sound diffracted from the top to the protected area. On the other hand, the two sides of the sound absorbing unit are connected, which can effectively increase the sound absorption effect in the lower frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the location of the sound barrier described in the background technology section.

[0020] Figure 2 It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention, wherein the anti-reflection device includes a rectangular sound absorbing unit.

[0021] Figure 3 This is an application of an embodiment of the present invention. Figure 2 Schematic diagram of the structure of the sound barrier of the anti-reflection device shown.

[0022] Figure 4It is a schematic diagram of the position of the sound barrier when modeling in the present utility model.

[0023] Figure 5a This is a schematic diagram of an embodiment of the present invention in which a sound absorbing structure is provided on the top of the sound barrier.

[0024] Figure 5b It is a schematic diagram of an upright sound barrier in an embodiment of the present utility model.

[0025] Figure 6 yes Figure 5a Sound absorption coefficient curve of medium sound absorbing structure.

[0026] Figure 7a and Figure 7b yes Figure 5a and Figure 5b Difference sound field diagram of the sound barrier shown.

[0027] Figure 7c is Figure 5a The sound absorption coefficient curve shown in the figure marks the sound absorption coefficient curve of the anti-diffraction sound barrier after the reduction of the sound pressure level in the protected area compared with the upright sound barrier.

[0028] Figure 8 This is a schematic structural diagram of an anti-diffraction device according to an embodiment of the present invention, in which a through hole is provided on only one side.

[0029] Figure 9 yes Figure 2 and Figure 8 The sound absorption coefficient curve of the anti-diffraction device shown.

[0030] Figure 10 It is a three-dimensional schematic diagram of an anti-diffraction device in an embodiment of the present utility model.

[0031] Figure 11 It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention, which includes a traditional wedge-shaped sound absorbing unit.

[0032] Figure 12a It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention. The anti-diffraction device includes discrete wedge-shaped sound absorbing units, and adjacent sound absorbing panels are arranged in a close-fitting manner.

[0033] Figure 12b It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention. The anti-diffraction device includes discrete wedge-shaped sound absorbing units, and adjacent sound absorbing panels are arranged at intervals.

[0034] Figure 13 It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention, wherein the anti-diffraction device includes a double-plate sound absorbing unit.

[0035] Figure 14a and Figure 14b yes Figure 13 Sound pressure level field diagrams of the sound barrier and upright sound barrier shown.

[0036] Figure 15a This is a schematic diagram of modeling various sound barriers during simulation in some embodiments of the present invention.

[0037] Figure 15b It is a schematic diagram of a model when performing simulation in some embodiments of the present invention.

[0038] Figure 15c is through Figure 15b Model pair Figure 15a Diffraction energy curves obtained after energy flux integration of various sound barriers.

[0039] Figure 15d Yes Figure 15c The curve graph is obtained by enlarging the area of ​​200Hz to 800Hz.

[0040] Figure 16a to Figure 16c yes Figure 15a The difference sound field diagram between other sound barriers and upright sound barriers.

[0041] Figure 17 It is a sound absorption coefficient curve of double-layer PET plate, rectangular glass fiber, glass fiber wedge and PET wedge type sound absorption units.

[0042] Figure 18 It is a schematic diagram of the sound wave transmitted by the sound-absorbing wedge.

[0043] Figure 19 It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention, wherein the anti-diffraction device includes an integrated sound absorbing unit provided with a cavity.

[0044] Figure 20 It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention, which includes an inverted wedge-type (without small cavity) sound absorption unit.

[0045] Figure 21 It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention, which includes an inverse wedge-type (with a small cavity) sound absorbing unit.

[0046] Figure 22a This is a structural diagram of two layers of sound-absorbing panels placed together in one embodiment of the present invention.

[0047] Figure 22b yes Figure 22a Schematic diagram of the two layers of sound-absorbing panels placed separately.

[0048] Figure 22c yes Figure 22a and Figure 22b Graph of the sound absorption coefficient for the structure shown.

[0049] Figure 23 It is a curve of sound absorption coefficient when the sound absorption unit is a wedge, an inverted wedge (with a small cavity) and an inverted wedge (without a small cavity).

[0050] Figure 24a It is a diffraction energy curve diagram of the upright sound barrier in the utility model and the sound barrier with double-plate sound absorbing unit, wedge (PET) sound absorbing unit, wedge (glass fiber) sound absorbing unit, rectangular glass fiber sound absorbing unit, inverse wedge (with small cavity) sound absorbing unit and inverse wedge (without small cavity) sound absorbing unit respectively.

[0051] Figure 24b Yes Figure 24a The curve graph is obtained by amplifying the frequency band above 200Hz.

[0052] Figure 25a and Figure 25b It is the difference sound field diagram between the sound barrier with a sound-absorbing unit of an inverted wedge structure (with a small cavity) and the upright sound barrier.

[0053] Figure 26 This is a schematic structural diagram of a sound absorbing unit according to an embodiment of the present invention. In the figure, the number of sound absorbing panels is an even number.

[0054] Figure 27a This is a structural diagram of a sound absorbing unit in an embodiment of the present invention. In the figure, the sound absorbing panel includes two sub-sound absorbing panels bonded together.

[0055] Figure 27b This is a structural diagram of a sound absorbing unit in an embodiment of the present invention. In the figure, the sound absorbing panel includes two sub-sound absorbing panels arranged at intervals.

[0056] Figure 28a It is a schematic diagram of a clamping mechanism in one embodiment of the present utility model.

[0057] Figure 28b yes Figure 29 Enlarged view of part I in the middle.

[0058] Figure 29 This is a schematic structural diagram of an anti-diffraction device according to an embodiment of the present invention. In the figure, the housing includes a bottom plate.

[0059] Figure 30 This is an embodiment of the present invention. Figure 29 Schematic diagram of the structure of the sound barrier of the anti-diffraction device shown.

[0060] Figure 31 This is an embodiment of the present invention. Figure 21 Schematic diagram of the structure of the sound barrier of the anti-diffraction device shown.

[0061] Figure 32a It is a schematic structural diagram of an upright sound barrier in an embodiment of the present utility model.

[0062] Figure 32b to Figure 32d Schematic diagrams of the structures of sound barriers with inverted wedge type (with small cavity), double-plate type and ordinary wedge type sound-absorbing units respectively.

[0063] Figure 33 It is an application Figure 32a to Figure 32d The frequency response curve of the protected area behind the sound barrier is shown.

[0064] Figure 34a It is a structural schematic diagram of an anti-diffraction device in an embodiment of the present invention. The shell of the anti-diffraction device is made of sound-absorbing material.

[0065] Figure 34b yes Figure 34a Enlarged view of part II.

[0066] Figure 35a This is a schematic diagram of an indoor sound insulation structure according to an embodiment of the present invention. In the figure, the anti-reflection device is connected to the ceiling.

[0067] Figure 35b This is a schematic diagram of an indoor sound insulation structure of an embodiment of the present utility model. In the figure, the anti-reflection device is connected to the sound barrier.

[0068] Figure 36a This is a schematic diagram of an indoor sound insulation structure in an embodiment of the present utility model. In the figure, the anti-reflection device includes a single-layer anti-reflection plate.

[0069] Figure 36b This is a schematic diagram of an indoor sound insulation structure in an embodiment of the present utility model. In the figure, the anti-reflection device includes a double-layer anti-reflection plate.

[0070] Figure 36c This is a schematic diagram of an indoor sound insulation structure of an embodiment of the present utility model. In the figure, the anti-reflection device includes a double-layer anti-reflection plate and is connected to the sound barrier.

[0071] Figure 36d It is a schematic diagram of an anti-reflection device in an embodiment of the present invention.

[0072] Figure 37 It is a sound absorption coefficient curve diagram of the anti-reflection device with a single-layer anti-reflection plate and the anti-reflection device with a double-layer anti-reflection plate in the utility model.

[0073] Figure 38 It is an insertion loss curve diagram of the anti-reflection device of the utility model with double-layer anti-reflection plates of different lengths.

[0074] Figure 39a It is a schematic diagram of an indoor sound insulation structure of an embodiment of the present utility model.

[0075] Figure 39b This is a schematic diagram of an indoor sound insulation structure in an embodiment of the present invention. Figure 39a An anti-reflection device having a single-layer anti-reflection plate is added.

[0076] Figure 39c This is a schematic diagram of an indoor sound insulation structure in an embodiment of the present invention. Figure 39b An anti-reflection device with a double-layer anti-reflection plate has been added.

[0077] Figure 39d This is a schematic diagram of an indoor sound insulation structure in an embodiment of the present invention. Figure 39c , an anti-diffraction device is installed on the top of the sound barrier.

[0078] Figure 40 yes Figure 39a to Figure 39d Insertion loss curve of indoor sound insulation structure shown. DETAILED DESCRIPTION

[0079] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some, rather than all, structures related to the present application are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0080] As used herein, the terms "comprise," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0081] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0082] like Figure 2 As shown, the present invention proposes an anti-diffraction device 51 , which includes a housing 2 and a sound absorbing unit 3 arranged inside the housing 2 .

[0083] The housing 2 includes a first side panel 20, a second side panel 21, and a top panel 22 connected to the tops of the first and second side panels 20, 21. The first and second side panels 20, 21 are provided with through-holes 200. A cavity 23 is formed between the first and second side panels 20, 21, and the top panel 22. The sound absorbing unit 3 is disposed within the cavity 23 and is made of a sound absorbing material (or porous material), such as fiberglass, rock wool, sponge, foam metal, PET (polyester fiber), or melamine foam.

[0084] like Figure 3 and Figure 4 As shown, when in use, the anti-diffraction device 51 is located on the top of the sound barrier 5, and the sound barrier 5 is located between the sound source 11 and the protection area 12, and is used to reduce the sound transmitted from the sound source 11 to the protection area 12. Through holes 200 are provided on the first side panel 20 and the second side panel 21, and sound can enter through the through holes 200 and be absorbed by the internal sound absorbing unit 3.

[0085] First, the anti-diffraction device 51 is internally provided with a sound-absorbing unit 3 that can come into contact with external sounds, that is, the top of the sound barrier 5 is relatively soft, which can reduce the impedance of the top. Compared with the traditional hard-top sound barrier, on the one hand, it can absorb sound at the top, and on the other hand, the smaller impedance can reduce the sudden change of impedance at the end, thereby reducing the pressure difference and particle vibration velocity on both sides of the sound barrier, thereby reducing the size of the sound diffracted from the top to the protection area 12.

[0086] In order to simulate the sound insulation effect of sound barrier 5, this paper uses Figure 4 The model shown is simulated. Figure 4 In the figure, the sound source 11 is on the left side of the sound barrier 5. During the simulation, the sound source is a point sound source. The sound source 11 is 0.5m away from the ground and 3m away from the sound barrier 5. The right side is the protection area 12.

[0087] In order to verify the effect of the sound absorption coefficient on the rear of the sound barrier 5, this paper compares the sound insulation effect of the sound barrier 5 with a sound absorption structure 5a on the top of the sound barrier 5 (hereinafter referred to as the anti-diffraction sound barrier 5) and the sound barrier 5 without a sound absorption structure on the top (hereinafter referred to as the upright sound barrier or normal sound barrier or ordinary sound barrier). Figure 5a and Figure 5b As shown in FIG, the two sound barriers 5 are of the same height, both 3 m, with the difference being that the top 0.5 m of one sound barrier 5 is a sound absorbing structure 5a, while the other is not provided with a sound absorbing structure 5a. The sound absorption coefficient and frequency of the sound absorbing structure 5a exhibit periodic fluctuations, as shown in FIG. Figure 6 As shown. Figure 6 It can be seen that the sound absorbing structure 5a has good sound absorption performance at about 200 Hz, 500 Hz and 820 Hz, and the sound absorption coefficient is less than 0.1 at about 350 Hz and 690 Hz.

[0088] The sound field distribution of the two sound barriers 5 in the protection area 12 under the same sound source is obtained by simulation, and the sound field of the upright sound barrier 5 at several frequencies (specifically 200Hz, 350Hz, 500Hz, 690Hz and 820Hz) is subtracted from the sound field of the anti-diffraction sound barrier 5 to obtain Figure 7a and Figure 7b The difference sound field diagram (also called the difference sound pressure level field diagram) shown in Figure 1 shows the sound pressure level in protected area 12, which is the difference in sound pressure (i.e., the increase in insertion loss) between the two types of sound barriers 5. A larger value indicates a greater drop in sound pressure. As can be seen from the diagram, the sound pressure level in protected area 12 is lower in the frequency bands with high sound absorption coefficients (200Hz, 500Hz, and 820Hz). In the frequency bands with low sound absorption coefficients (350Hz and 690Hz), the sound pressure level in the area protected by sound barrier 5 is almost the same as that of the upright sound barrier 5. Figure 7c In the graph, the reduction in sound pressure level of the anti-diffraction sound barrier 5 at the peaks and valleys of the sound absorption coefficient compared to the upright sound barrier 5 in the protection area 12 is marked.

[0089] This shows that the anti-diffraction effect is directly related to the sound absorption performance of the top structure of sound barrier 5. It is speculated that one possible reason for this is that the strong sound absorption structure at the top absorbs noise energy, and the diffracted energy is naturally weakened. Therefore, installing an anti-diffraction device 51 with excellent sound absorption performance at the top of sound barrier 5 will effectively reduce the sound pressure of sound waves diffracted from the top of sound barrier 5 to protected area 12, thereby improving the sound insulation effect of sound barrier 5.

[0090] In the second aspect, in the present invention, both the first side plate 20 and the second side plate 21 are provided with through holes 200, which is different from the first side plate 20 which is only provided with holes facing the sound source and the second side plate 21 which is not provided with holes facing the protection area 12 (refer to FIG. Figure 8) structure can effectively increase the sound absorption effect in the lower frequency band. Figure 9 As shown, Figure 9 Shown Figure 2 and Figure 8 The curves of the sound absorption coefficients of the two structures. In the figure, the conventional layout curve corresponds to Figure 8 The structure shown, the anti-diffraction layout curve corresponds to Figure 2 In the structures shown, both are filled with sound-absorbing materials such as glass fiber and asbestos in the outer shell 2. It can be seen from the figure that with the increase of frequency, the sound absorption coefficient of the conventional layout gradually increases from 0, but the sound absorption coefficient of the anti-diffraction layout gradually increases from 0.5. In terms of frequency band, the low-frequency sound absorption coefficient of the anti-diffraction layout is much higher than that of the conventional layout, which can further improve the sound insulation effect of the sound barrier 5.

[0091] In some embodiments, to ensure sound absorption, the perforation ratio of the first side panel 20 and the second side panel 21 is greater than or equal to 15% to ensure that sound waves can reliably enter the cavity 23. The perforation ratio can be understood as the ratio of the total area of ​​all through holes 200 in the side panel to the area enclosed by the outer contour of the side panel. The number of through holes 200 can be one or more, as long as the ratio of the total area of ​​all through holes 200 to the area enclosed by the outer contour of the side panel in which they are located is greater than or equal to 15%.

[0092] Optionally, in order to ensure the reliability of sound transmission, there are multiple through holes 200. The more evenly they are distributed on the side panels, the more conducive it is to ensure the balance of sound absorption in different areas of the anti-diffraction device, thereby improving the sound absorption effect. Therefore, the through holes 200 can be evenly distributed on the side panels. The shape of the through holes 200 is not limited, for example, it can be a circular hole (refer to Figure 10 ), square hole, triangular hole, elliptical hole, long hole (reference Figure 32b ) or special-shaped holes, etc. In some embodiments, a 10 mm hole can be punched every 20 mm.

[0093] In some embodiments, the housing 2 is made of a hard material with an impedance that is at least 100 times that of air. For example, it can be made of metal or a material with a relatively hard acoustic impedance relative to air, such as plastic. It should be noted that, unless otherwise specified, in this document, "impedance" refers to acoustic impedance. The thickness of the housing 2 can be adjusted based on the strength and rigidity of the material. Generally, a thickness of 1 to 5 mm is preferred in engineering, but is not limited thereto. A hard housing can reflect sound waves, while the through holes can guide sound waves into the sound-absorbing unit, reducing diffraction and providing excellent sound insulation for both low and medium-high frequencies. In some embodiments, the housing 2 is made of a sound-absorbing material, such as the same material as the sound-absorbing unit 3, to further enhance the anti-diffraction effect. Since the sound-absorbing material itself allows sound waves to penetrate the interior, there is no need to drill holes in the housing 2 (although drilling holes is possible). Its acoustic impedance and density can be set to be lower than those of a hard housing.

[0094] It is understood that the outer shell 2 protects the internal sound-absorbing unit 3. When the sound barrier 5 is used outdoors, the requirements for wind and rain protection are relatively high, and the outer shell 2 can be made of a hard material (of course, it can also be a sound-absorbing material). When the sound barrier 5 is used indoors, the requirements for wind and rain protection are relatively low, and it can be made of a hard material or a sound-absorbing material. To improve the overall waterproof effect, the surface of the sound-absorbing unit 3 can be sprayed with a waterproof coating. When the outer shell 2 is made of a sound-absorbing material, a waterproof coating can also be sprayed.

[0095] The structure of the sound absorbing unit 3 can be varied. The following describes several structures of the sound absorbing unit 3 as examples (Examples 1 to 7). In the present invention, the length direction, width (or thickness) direction, and height direction are indicated with reference to the directions shown in the drawings.

[0096] Example 1 - Block Type

[0097] like Figure 2 As shown, in this embodiment, the sound absorbing unit 3 is in a block shape filled in the cavity 23. The sound absorbing unit 3 is made of sound absorbing materials such as glass fiber or PET.

[0098] In some embodiments, the width of the sound absorbing unit 3 gradually increases from the top plate 22 toward the side away from the top plate 22 , such as shown in Embodiment 2 and Embodiment 3.

[0099] Example 2 - Traditional wedge type (also called integrated wedge type, ordinary wedge type)

[0100] In this embodiment, Figure 11 As shown, the sound absorbing unit 3 is an integrally formed sound absorbing wedge, the cross section of which is conical, and the top of the sound absorbing wedge faces the top plate 22 .

[0101] Example 3 - Discrete Wedge

[0102] In this embodiment, Figure 12a and Figure 12b As shown, the sound absorbing unit 3 includes a plurality of sound absorbing panels 30 arranged along the width direction of the housing 2. The heights of the plurality of sound absorbing panels 30 gradually increase from the first side panel 20 and the second side panel 21 toward the middle of the cavity 23. The closer to the middle, the greater the height of the sound absorbing panel 30. In this way, the width of the sound absorbing unit 3 increases toward the sides.

[0103] Figure 12a In the embodiment, two adjacent sound absorbing panels 30 are attached to each other. Figure 12b In the embodiment, two adjacent sound absorbing panels 30 are arranged at intervals.

[0104] Example 4 - Double Plate Type

[0105] In this embodiment, Figure 13 As shown, the sound absorbing unit 3 includes two sound absorbing panels 30 that are spaced apart from each other. The two sound absorbing panels 30 are separated by air and are made of sound absorbing material.

[0106] Optionally, the two sound absorbing panels 30 are respectively fitted with the inner walls of the first side panel 20 and the second side panel 21 to maximize the distance between the sound absorbing panels 30. The larger the distance between the two sound absorbing panels 30, the larger the space between them, which is conducive to obtaining a good sound absorption effect at low frequencies.

[0107] Optionally, the thickness of the sound absorbing plate 30 is 3 to 36 mm, and the density of the sound absorbing plate 30 is 110 to 420 kg / m 3 The greater the density, the thinner the sound absorbing plate 30 can be, so that the acoustic impedance of the sound absorbing plate 30 is more closely matched with the acoustic impedance of air, thereby improving the sound absorption effect and the anti-diffraction effect.

[0108] For example, for ordinary boards (density of about 180 to 230 kg / m 3 For example, PET board), the thickness of the sound absorbing board 30 is preferably 6 to 24 mm; for high-density board (density of about 360 to 420 kg / m 3 , such as PET board), the thickness of the sound absorbing board 30 is preferably 3 to 8 mm; for low-density boards (density of about 110 to 180 kg / m 3 , such as PET board), the thickness of the sound absorbing board 30 is preferably 10 to 36 mm.

[0109] The sound pressure level field of the sound barrier 5 with double-plate sound absorbing units 3 and the sound pressure level field of the upright sound barrier 5 are obtained by modeling, and the sound pressure level field of the sound barrier with double-plate sound absorbing units 3 is subtracted from the sound pressure level field of the upright sound barrier 5 to obtain Figure 14a andFigure 14b The sound pressure level field diagram shown in the figure shows that the normal sound barrier is an upright sound barrier, and the anti-diffraction sound barrier is a sound barrier with double-panel sound absorbing units 3. As can be seen from the figure, the anti-diffraction sound barrier has an overall improved sound insulation effect in the low-frequency broadband range compared to the upright sound barrier 5.

[0110] In order to verify the effect of different structures of sound absorbing units 3 on the anti-diffraction effect, this section uses finite element software to model and calculate the effect of the top structure of the sound barrier 5 on the diffraction effect. Figure 15a , the structure of each model is as follows:

[0111] ① Vertical sound barrier 5, height 3.5m, thickness 0.1m.

[0112] ②Wedge-type sound barrier 5, height 3.5m, the top 0.5m is a triangular wedge, the bottom width of the triangular wedge is 0.1m, and the height is 0.5m.

[0113] The wedge materials are selected from the following two types:

[0114] Flow resistance rate Porosity Tortuosity factor Thermal characteristic length Viscous characteristic length Standard PET plate 74031 0.967 1.018 7.58e-05 4.96e-3 Low density glass fiber 11900 0.989 1.011 3.02e-04 1.43e-04

[0115] ③ Rectangular sound absorbing material (i.e. block-type sound absorbing unit 3) sound barrier 5, height 3.5m, top 0.5m is rectangular sound absorbing material, the width of the rectangle is 0.1m, the height is 0.5m, and the material is low-density glass fiber.

[0116] ④ Double-layer plate type sound barrier 5, the material of the sound absorbing plate 30 is PET, the thickness of the sound absorbing plate 30 is 9 mm, the height is 0.5 m, the distance between the two layers of plate is about 0.08 m, and they are separated by air.

[0117] Schematic diagrams of the four models are shown in Figure 15a .

[0118] The model is modeled by finite element software. Figure 15b As shown, the black dot on the left is the sound source, the barrier is located at the lower left, and the energy flow of the blue line segment on the right is integrated to obtain the sound wave energy diffracted into the protection area.

[0119] The simulation results are as follows Figure 15c and Figure 15d As shown, Figure 15c is the result of the energy flow integration of the blue segment, Figure 15d For Figure 15c The curve graph is obtained by enlarging the area of ​​200Hz to 800Hz.

[0120] Some conclusions can be drawn from the figure:

[0121] ① The energy diffracted by the upright sound barrier 5 (blue line) is the highest;

[0122] ② The wedge type has a better anti-diffraction effect than the upright type, and the wedge made of glass fiber is more effective than the wedge made of PET. This is because the use of PET sheet to make the wedge has a higher density and higher impedance, so the effect is not good (red line). The use of low-density glass fiber to make the wedge is better than the wedge made of PET sheet (light blue line segment). Therefore, reducing the density of the sound absorbing unit 3 is conducive to improving the sound insulation effect of the sound barrier 5;

[0123] ③ The rectangular sound-absorbing material sound barrier 5 (purple) has a similar effect to the double-layer PET board (9mm), with the smallest diffraction energy.

[0124] The same effect can be seen from the sound field diagram. Figure 16a to Figure 16c These are the difference sound field diagrams (increment of insertion loss) of the upright sound barrier and the wedge-shaped, rectangular, and double-plate sound barriers 5 at 100Hz, 200Hz, and 300Hz respectively:

[0125] Figure 17 The following is a graph of the sound absorption coefficient of the sound absorbing units in the above four structures (double-layer PET plate, rectangular glass fiber, glass fiber wedge and PET wedge). Figure 16a to Figure 16c The three field diagrams are basically consistent with the sound absorption coefficient curve. Considering the reasons, the sound absorption coefficients of several structures are analyzed as follows:

[0126] ① Considering that the structure is installed on the top of the sound barrier 5, its installation method is consistent with the direction of sound wave propagation. Figure 18 As shown, sound waves basically propagate from left to right, so the wedge structure does not necessarily have good sound absorption performance for sound waves propagating laterally.

[0127] ②The choice of wedge material is also very important. If PET sheet is used to make the wedge, its density and flow resistance are too large, impedance mismatch occurs, and sound absorption performance is weak. Therefore, a lighter and fluffier material should be selected to make the wedge. The low-density glass fiber wedge (light blue curve) has better low-frequency sound absorption performance than the PET wedge (red curve).

[0128] ③ By designing a double-layer PET board, higher sound absorption performance at low frequencies can be achieved, and its effect is comparable to that of a 10cm thick low-density glass fiber ( Figure 17 medium blue and green curves).

[0129] ④ Structures with good sound absorption performance also have better anti-diffraction effects. The trends of the sound absorption coefficient curve and the diffraction energy curve can confirm each other.

[0130] The key of the anti-diffraction sound absorption structure is that the sound absorption material is open on both sides, and there is no sealed baffle, so that the sound wave can be transmitted from the left side to the right side, and thus the low-frequency sound absorption performance is high. By setting the shell 2 with holes on both sides, or setting the shell 2 to be made of sound absorption material, the sound absorption unit 3 can be realized to be open on both sides.

[0131] Through the above analysis, it can be found that the low-frequency sound absorption coefficient of the double-layer PET plate can be better than that of the wedge structure, but the medium and high frequency performance may not be better than that of the wedge. Therefore, the structure of the sound absorption unit 3 can be further improved. In some embodiments, the sound absorption unit 3 is set to an inverse wedge structure, that is, a cavity 31 in the shape of an inverted wedge (or an inverse wedge shape, a reversed wedge shape) is arranged at the top of the sound absorption unit 3, and the width of the cavity 31 decreases away from the side where the top plate 22 is located, for example, the structures described in embodiments 5 to 7.

[0132] In this way, the sound absorption unit 3 at the bottom is thicker and can play a better sound insulation role, the sound absorption unit 3 at the top gradually decreases in thickness to form a gradient, in addition, since the sound absorption units 3 on both sides are clamped to form a cavity 31, the structure at the top can have very good sound absorption effect, the overall structure has good sound absorption performance, can reduce the noise diffraction of low frequency, and has a gradual structure, which can weaken the noise diffraction of high frequency, and has good wide frequency characteristics, so it can have the advantages of medium and high frequency of the wedge and the low frequency performance of the double-layer thin plate.

[0133] If it is desired to improve the low-frequency sound absorption effect, the gradient (i.e. the rate of decrease of the height of the sound absorption material from both sides to the middle) should decrease rapidly, which will approach the effect of the double-plate structure, if it is desired to improve the sound absorption effect of medium and high frequency, the gradient decrease rate should be lower. The design of the decrease rate is not limited, for example, it can be linear decrease or exponential decrease, etc.

[0134] Embodiment 5

[0135] As shown in Figure 19 , in this embodiment, the sound absorption unit 3 is in the shape of an integral block, and an inverted wedge-shaped cavity 31 is arranged at the upper end of the sound absorption unit 3.

[0136] Embodiment 6-Inverse wedge type (without small cavities)

[0137] In this embodiment, as shown in Figure 20 , the sound absorption unit 3 includes a plurality of sound absorption plates 30 arranged along the width direction of the shell 2, and adjacent two sound absorption plates 30 are attached together, and the height of the plurality of sound absorption plates 30 gradually decreases from the first side plate 20 and the second side plate 21 to the middle of the cavity 23, so as to form an inverse wedge-shaped cavity 31 at the top of the sound absorption unit 3.

[0138] To make full use of the cavity 23, the two outermost sound absorption panels 30 of the sound absorption unit 3 are respectively connected with the first side plate 20 and the second side plate 21.

[0139] Example 7 Reverse Wedge Type (with small cavity)

[0140] As shown in Figure 21 , the difference between this embodiment and example 6 is that the plurality of sound absorption panels 30 of the sound absorption unit 3 are arranged at intervals along the width direction of the shell 2, that is, the adjacent two sound absorption panels 30 are not attached together but are arranged at intervals, and there is an interval space (i.e. with a small cavity) between the adjacent two sound absorption panels 30, which can further improve the sound absorption effect.

[0141] The sound absorption panel 30 arranged at intervals will have a better sound absorption effect than the sound absorption panel 30 attached together, for example, under the same space of 90mm, two polyester fiber panels with a thickness of 9mm and a surface density of 200kg / m 2 are respectively arranged to be placed together (for reference Figure 22a ) and placed separately (for reference Figure 22b ), and the sound absorption coefficient is as shown in Figure 22c , it can be seen from Figure 22c that the sound absorption coefficient in most frequency ranges after being placed separately is greater than that of being placed together, and it is speculated that the reason is that the sound absorption panel 30 arranged separately is conducive to adjusting the acoustic impedance, and the sound absorption panel 30 attached together may have too large acoustic impedance, and the introduction of the gap can appropriately reduce the impedance and be more matched with the acoustic impedance of the air. In addition, the sound wave will produce multiple reflections in the gap, enhancing absorption. Therefore, the sound absorption effect of the sound absorption unit 3 corresponding to example 7 will be better than that of the sound absorption units 3 corresponding to examples 6 and 5. In addition, for the double-panel type sound absorption unit 3 of example 4, the greater the distance between the two sound absorption panels 30, the more conducive to enhancing the sound absorption performance. Further, in the discrete wedge structure, the sound absorption effect of the sound absorption panel 30 arranged at intervals between the adjacent two sound absorption panels 30 is better than that of the sound absorption panel 30 attached between the adjacent two sound absorption panels 30.

[0142] The sound absorption coefficient curves of the traditional wedge, reverse wedge design (with small cavity) and reverse wedge design (without small cavity) are as shown in Figure 23 , the small cavity refers to the interval space between the adjacent two sound absorption panels 30, and the no small cavity and the small cavity correspond to the structures of the adjacent two sound absorption panels attached and arranged at intervals respectively. As can be seen from the figure, the sound absorption coefficient of the reverse wedge type sound absorption unit is significantly improved, and the sound absorption coefficient can be further increased after appropriately adding the cavity.

[0143] Further comparison of the diffracted sound energy in the following cases: "upright sound barrier", "double-plate structure", "wedge (PET)", "wedge (glass fiber)", "rectangular glass fiber", "inverse wedge (with small cavity)" and "inverse wedge (without small cavity)" Figure 24a As shown, Figure 24a In the figure, the horizontal axis is frequency and the vertical axis is diffraction energy. As can be seen from the figure, at 100Hz, the diffraction energy of the double plate and rectangular glass fiber is the lowest (about 0.3), the upright type is the highest (about 0.85), and the diffraction energy of the inverse wedge (with a small cavity) (purple, about 0.45) is between the wedge (0.55-0.6) and the double plate. Zooming in on the results above 200Hz, we get Figure 24b The graph shows that the inverted wedge (with a small cavity, purple line) is slightly better than the PET wedge (green line), but still outperforms the other structures. The double-panel structure performs well at low frequencies, but exhibits fluctuations in the mid- and high-frequency range (400Hz-700Hz). Furthermore, among the inverted wedges, the structure with a small cavity (purple line) also outperforms the bonded structure without a cavity (yellow line). This is presumably due to the increased density after bonding, which reduces sound absorption at the top. In summary, the inverted wedge with a small cavity is a hybrid structure that combines the characteristics of double-panel and wedge structures. Its low-frequency performance lies somewhere between those of double-panel and wedge structures, while its mid- and high-frequency performance is nearly equivalent to that of a traditional wedge.

[0144] Figure 25a and Figure 25b The difference sound field diagram from 100Hz to 800Hz is shown between the sound barrier 5 with an inverted wedge structure (with a small cavity) and the upright sound barrier 5 to reflect the increase in insertion loss. The difference sound field diagram is obtained by subtracting the sound pressure level field of the upright sound barrier 5 from the sound pressure level field of the inverted wedge (with a small cavity) sound barrier 5. It can be seen from the figure that the inverted wedge (with a small cavity) sound barrier 5 has better sound insulation effect than the upright sound barrier 5 in the entire low-frequency band.

[0145] Optionally, the sound absorbing panel 30 has five or more layers to ensure its anti-diffraction effect. More layers provide finer variations and a higher degree of homogenization, which can increase sound absorption performance over a wider frequency band, thereby enhancing its anti-diffraction effect. Furthermore, the sound absorbing panel 30 may have seven or more layers.

[0146] Optionally, the spacing between two adjacent sound absorbing panels 30 does not exceed three times the thickness of the sound absorbing panels 30 , so that the width of the sound absorbing unit 3 is more appropriate, or when the width of the sound absorbing unit 3 is constant, there are an appropriate number of sound absorbing panels 30 .

[0147] Optionally, the spacing between two adjacent sound absorbing panels 30 is no less than 2 mm, to facilitate control of the spacing between the two sound absorbing panels 30 and to reduce acoustic impedance to a certain extent. The thickness of the sound absorbing panels 30 can be, for example, 5 to 24 mm. In some embodiments, the thickness of the sound absorbing panels 30 is the same as the spacing between two adjacent sound absorbing panels 30, for example, 9 mm panels + 9 mm spacing, 18 mm panels + 18 mm spacing, 5 mm panels + 5 mm spacing, etc.

[0148] The spacing between two adjacent sound-absorbing panels 30 is related to their density and can regulate the impedance of the structure. According to homogenization theory, the sound-absorbing panels 30 and the intervening air layer form a uniform structure in the long-wave limit (wavelength >> structure size, at least 5 times greater). Their equivalent density is the arithmetic mean of the two, and their bulk modulus is the harmonic mean of the two:

[0149] ρ s =fρ p +(1-f)ρ a , where ρ s is the equivalent density of the overall structure, ρ p is the equivalent acoustic density of the sound absorbing panel 30, ρ a is the density of air, f is the filling rate of the plate, specifically written as:

[0150] Wherein dp is the thickness of the sound absorbing plate 30, and da is the thickness of the intervening air layer.

[0151] K s is the equivalent bulk modulus of the overall structure, K p is the equivalent acoustic modulus of the sound absorbing panel 30, K a is the bulk modulus of air, and f is the filling rate of the plate.

[0152] The impedance of the structure can be written as:

[0153]

[0154] Therefore, the thickness dp of the air layer can affect the filling rate, further affect the equivalent density and equivalent modulus of the structure, and ultimately affect the equivalent impedance. The closer the equivalent impedance is to the air impedance, the higher the impedance matching degree, which is more conducive to improving the sound absorption effect, thereby improving the anti-diffraction effect and sound insulation effect.

[0155] Therefore, different spacings can be selected for different panels to make the sound absorbing unit 3 have a lower equivalent impedance and be more compatible with the air impedance. For example:

[0156] When using normal density sound absorbing panels (density of about 180-230 kg / m 3 , such as PET board), the filling rate f of the sound-absorbing board should be between 0.4 and 0.6;

[0157] When using a sound-absorbing board with a higher density, the filling rate should be reduced accordingly. For example, when the gram weight is doubled (i.e. 360-460 kg / m 3 , such as PET board), f should be between 0.1 and 0.3;

[0158] When choosing a sound-absorbing board with a lower density, the filling rate should be increased accordingly, for example, the gram weight should be reduced to 70% of the original (i.e. 126-161 kg / m 3 , such as PET board), f should be between 0.6 and 0.9.

[0159] Optionally, the ratio of the height H1 of the middle sound absorbing plate 30 of the sound absorbing unit 3 to the height H2 of the outermost sound absorbing plate 30 of the sound absorbing unit 3 is greater than or equal to 10%. It is understood that the number of the middle sound absorbing plate 30 of the sound absorbing unit 3 can be one or two or more, for example, Figure 21 In the illustrated embodiment, the number of the sound absorbing panels 30 is an odd number, and in this case, the number of the middlemost sound absorbing panel 30 is one. Figure 26 In the illustrated embodiment, the number of the sound absorbing panels 30 is an even number. In this case, there are two middle sound absorbing panels 30 with the same height.

[0160] It is understood that the sound absorbing panel 30 may include one or more sub-sound absorbing panels 300 of the same height, and the sub-sound absorbing panels 300 of the same sound absorbing panel 30 may be attached to each other or spaced apart. Figure 27a and Figure 27b As shown, each sound absorbing panel 30 includes two sub-sound absorbing panels 300 . Figure 27a In the embodiment shown, the two sub-sound absorbing panels 300 of each sound absorbing panel 30 are arranged in close contact with each other. Figure 27b In the illustrated embodiment, the two sub-sound absorbing panels 300 of each sound absorbing panel 30 are arranged at intervals, which is beneficial to further improve the sound absorption coefficient and enhance the sound insulation effect.

[0161] The method for securing the sound absorbing panel 30 to the housing 2 is not limited. In some embodiments, as shown in FIG28 , the anti-diffraction device 51 includes a snap-fit ​​mechanism 4 connected to the housing 2. The snap-fit ​​mechanism 4 includes a plurality of slots 40, into which the sound absorbing panel 30 is inserted and secured. It is understood that the snap-fit ​​mechanism 4 includes at least the slots 40 corresponding to the positions and number of the desired sound absorbing panels 30. It is also understood that when a sound absorbing panel 30 includes two or more sub-sound absorbing panels 300, the snap-fit ​​mechanism 4 includes at least the slots 40 corresponding to the positions and number of the desired sub-sound absorbing panels 300.

[0162] The clamping mechanism 4 comprises a plurality of elastic clamping arms 41, and a slot 40 is formed between two adjacent elastic clamping arms 41, the width of the slot 40 is less than the thickness of the sound absorption plate 30, so that the sound absorption plate 30 can be clamped by the two elastic clamping arms 41, thereby being more firmly fixed.

[0163] Further, at least two ends of the sound absorption plate 30 in the length direction are provided with the clamping mechanism 4 to ensure the firmness of the fixation.

[0164] Optionally, the clamping mechanism 4 is located at the bottom of the shell 2 and connected to the bottom of the sound absorption plate 30. Of course, the position of the clamping mechanism 4 is not limited to this, for example, the clamping mechanism 4 can also be arranged at the middle or top of the sound absorption plate 30, or the clamping mechanism 4 can be arranged at two or more positions of the bottom, middle and top of the sound absorption plate 30 at the same time, so as to further enhance the firmness of the fixation.

[0165] In order to fully utilize the space of the cavity 23 and improve the sound absorption and anti-diffraction effects, the ratio of the height of the sound absorption unit 3 to the height of the cavity 23 is not less than 90%, and the top of the sound absorption unit 3 can be in contact with the top plate 22 or there can be a gap (not in contact). Further optionally, the height of the sound absorption unit 3 is consistent with the height of the cavity 23, and is in contact with the top plate 22. The height of the sound absorption unit 3 is the maximum dimension in the height direction, and in the case where the sound absorption unit 3 comprises a plurality of sound absorption plates 30, since the bottoms of the sound absorption plates 30 are substantially flush and located at the bottom of the cavity, the height of the sound absorption unit 3 is equal to the height of the sound absorption plate 30 with the highest height.

[0166] The height of the cavity 23 is limited by the mounting structure, specifically, by the bottom support structure thereof.

[0167] In some embodiments, as shown in Figure 29 and Figure 30 , the shell 2 comprises a bottom plate 24 connected to the first side plate 20 and the second side plate 21, and the top plate 22 and the bottom plate 24 are oppositely arranged, and the cavity 23 is formed between the first side plate 20, the second side plate 21, the top plate 22 and the bottom plate 24, at this time, the bottom plate 24 is the bottom support structure of the cavity 23, and the sound absorption unit 3 is supported by the bottom plate 24, and the height of the cavity 23 is the distance from the bottom plate 24 to the top plate 22. Optionally, the top plate 22 is also provided with one or more through holes 200, so that the sound waves passing from above the top plate 22 can also enter the cavity 23 through the through holes 200 for absorption, thereby further improving the anti-diffraction effect. The perforation rate of the top plate 22 is optionally greater than or equal to 15%.

[0168] In some embodiments, the shell 2 does not comprise a bottom plate 24, as shown in Figure 3 and Figure 31As shown, after the anti-diffraction device 51 is installed on the base 50, the cavity 23 uses the base 50 of the sound barrier 5 as a bottom support structure, and the sound absorption unit 3 is supported by the base 50. At this time, the distance from the top surface 500 of the base 50 to the top plate 22 is the height of the cavity 23.

[0169] The utility model also proposes a sound barrier 5, it includes the anti-diffraction device 51 described above, and the anti-diffraction device 51 is arranged at the top end of the sound barrier 5.

[0170] As shown in Figure 3 , Figure 30 and Figure 31 The sound barrier 5 also includes a base 50, and the anti-diffraction device 51 is connected to the top of the base 50. Optionally, the anti-diffraction device 51 is fixedly connected to the base 50 through the shell 2, and the connection mode is not limited, for example, it can be fixed by bolts, buckled and / or glued.

[0171] The base 50 can be made of ordinary cement, steel structure, wood board, composite board or other materials, and it can be used as a hard boundary sound insulation.

[0172] The base 50 can be equal or unequal width, for example, it can be a trapezoidal structure with a small upper and a large lower. The width of the top surface 500 of the base 50 can be the same as the width of the anti-diffraction device 51, slightly smaller than the anti-diffraction device 51, or larger than the width of the anti-diffraction device 51, as long as it can stably fix the anti-diffraction device 51. Optionally, the width of the sound barrier 5 is 60-200 mm, the height is 2-5 m, and the height of the anti-diffraction device 51 accounts for 10%-40% of the total height of the sound barrier 5.

[0173] The structure of the sound absorption unit 3 in the anti-diffraction device 51 can refer to the above, and the following several different structures of sound absorption unit 3 are assembled into the sound barrier 5, and the sound insulation effect is simulated and tested.

[0174] As shown in Figure 32a to Figure 32d Four kinds of sound barriers 5 are tested for comparison, one of which is a vertical sound barrier 5 (refer to Figure 32a ), which only includes a base 50, and the height of the base 50 is about 3 m. The other three sound barriers 5 include an anti-diffraction device 51, and the total height of the sound barrier 5 is about 3 m, the height of the anti-diffraction device 51 is about 1 m, and the height of the base 50 is about 2 m. The width of the four sound barriers 5 is 0.12 m.

[0175] Reference Figure 32b to Figure 32dThe sound absorption units 3 in the three sound barriers 5 provided with the anti-diffraction device 51 are respectively inverse wedge structure (with small cavity), double-plate structure and ordinary wedge structure. The sound absorption units 3 are made of the same material, i.e. standard polyester fiber PET material produced by Jiangsu Baijialixinxiliao Technology Co., Ltd., the porosity of the material is about 0.97, and the flow resistance rate is 74000 Pa·s / m 2 , the thermal characteristic length is 7.6e-5 m, the viscous characteristic length is 4.96e-4 m, and the tortuosity factor is 1.02. Figure 32a and Figure 32b The thickness of the sound absorption plate 30 in each of the sound barriers 5 is 9 mm. The inverse wedge type sound absorption unit 30 includes 7 sound absorption plates 30, the outermost PET plate is the highest, the middle one is the lowest, and the heights of the 7 sound absorption plates 30 from left to right are about 1 m, 0.7 m, 0.5 m, 0.2 m, 0.5 m, 0.7 m and 1 m respectively. The arrangement structure can refer to Figure 21 .

[0176] Figure 33 The sound pressure level curves of the protection areas 12 behind the four sound barriers 5 are shown. When measuring, the sound barriers 5 are changed, and other parameters remain unchanged. As can be seen from the figure, the sound pressure level behind the hard wall (i.e. the vertical sound barrier 5) is the largest (block line), and the sound insulation effect is the worst.

[0177] For low frequency (<200Hz), the sound pressure level from small to large is: double-plate structure < inverse wedge structure < wedge structure < hard wall. Therefore, the double-plate structure can significantly increase the sound insulation amount in the low frequency area.

[0178] For medium and high frequency (200Hz-700Hz), the sound pressure level from small to large is: wedge structure < inverse wedge structure < double-plate structure < hard wall, so the wedge structure can significantly increase the sound insulation amount in the medium and high frequency area.

[0179] Overall, the effect of the inverse wedge structure is between the two, and has the characteristics of both the double-plate structure and the wedge structure, and the effective frequency band is wider.

[0180] It can be understood that the sound barrier 5 can be applied to various scenes, for example, it can be applied outdoors, such as on both sides of the road, highway and elevated composite road. For another example, it can be applied indoors and used as a sound insulation wall to divide a large indoor space into several smaller spaces.

[0181] The application of the sound barrier 5 in the indoor space is further described below. The sound barrier 5 applied in the indoor space can also be referred to as a sound insulation wall.

[0182] The applicant found that there are usually several problems in building a partition wall in the indoor space (especially in a large flat) to form independent small compartments:

[0183] 1. After the partition wall is built, its position is basically fixed and it is difficult to move;

[0184] 2. In order to meet the needs of wall sound insulation, the wall often needs to be connected to the ceiling and the ground;

[0185] 3. For fire safety, the cubicle also needs to be equipped with complete fire sprinklers and other equipment and measures, which increases complexity and cost.

[0186] Many companies renting office floors in office buildings want to build flexible workspaces to suit their needs, but when the lease expires, they need to restore the existing space. Dismantling these spaces is complex, and even more time-consuming and labor-intensive when firefighting equipment is involved.

[0187] The aforementioned issues could be addressed if lightweight, portable soundproof walls could be used to construct office spaces. For example, using movable walls to construct rooms without a ceiling would facilitate installation and removal, improve air circulation, and avoid complex firefighting measures. However, these open walls present significant sound leakage, resulting in poor sound insulation and a high risk of noise disturbance.

[0188] By using the sound barrier 5 described above to build a room, you can take advantage of its excellent sound insulation effect to reduce noise interference, and it is easy to move and disassemble, and the cost is lower.

[0189] In order to facilitate the movement of the sound barrier 5, its base 50 can be made of a suitable lightweight material. In some embodiments, the base 50 includes a keel (such as a light steel keel) and a sound-absorbing material filled in the keel. The sound-absorbing material can be, for example, rock wool, glass fiber, polyester fiber, foam metal, sponge or melamine foam or a combination of these materials, with a density of 100 to 400 kg / m 3 The base 50 also includes a gypsum board or wood board disposed on the keel surface. For example, a double layer of gypsum board or wood board can be laid on the keel surface with staggered joints. The total thickness of the gypsum board or wood board can be 6 to 12 mm to achieve good sound insulation. In other embodiments, the base 50 can be made of thick wood boards.

[0190] In order to facilitate the movement of the sound barrier 5, rollers or slide rails can be set at the bottom of the base 50. In addition, in order to facilitate the sound barrier 5 to remain in the current position after movement, a fixing device can be set.

[0191] The structure of the base 50 is not a technical focus, and those skilled in the art can use the partition wall in the existing technology as the base 50.

[0192] It can be understood that, due to the anti-diffraction device 51 arranged above the base 50, the base 50 can reflect sound, and the sound can be absorbed and reduced by the anti-diffraction device 51 to reduce diffraction at the top, so that the sound barrier 5 has good sound insulation performance, and thus the sound insulation effect can be improved compared with a conventional sound insulation wall without a top cover, and compared with a scheme of arranging sound-absorbing materials on the surface of the entire base 50, the cost can be significantly reduced while ensuring the sound insulation effect.

[0193] However, there are still some differences between the application of the sound barrier 5 in an indoor area and an open outdoor area. Specifically, when the sound barrier 5 is applied indoors, there is a ceiling above the sound barrier 5, which does not exist in an open outdoor area. The ceiling will reflect sound waves down to the other side of the wall, causing a sharp decrease in sound insulation, so it is still necessary to improve the sound insulation structure indoors to further improve the sound insulation effect.

[0194] Therefore, the utility model also provides an indoor sound insulation structure, which comprises the sound barrier 5 and the anti-reflection device 6 arranged above the sound barrier 5. The anti-reflection device 6 is arranged apart from the sound barrier 5 and is used to absorb sound transmitted from below to the anti-reflection device 6. The anti-reflection device 6 is made of sound-absorbing material at least towards part of the sound barrier 5 to achieve sound absorption effect and further reduce sound reflected from one side of the sound barrier 5 to the other side.

[0195] It can be understood that the sound barrier 5 can be a common sound barrier 5 (such as a partition wall in the prior art), or a sound barrier 5 with the anti-diffraction device 51 as described above. Since the anti-reflection device 6 is arranged, even if a common sound barrier 5 is used, better sound insulation effect can be achieved. After the sound barrier 5 with the anti-diffraction device 51 is arranged, the sound insulation effect can be further improved.

[0196] Since the sound barrier 5 is used indoors, the requirements for waterproofing and windproofing are relatively low, so the shell 2 can be made of sound-absorbing materials in addition to the hard materials such as plastics or metals described above, such as PET boards or glass fibers, to further improve the sound absorption effect. Figure 34a and Figure 34b , Figure 34b is Figure 34aThe enlarged view of the middle II part, in the illustrated embodiment, the shell 2 comprises a first side plate 20, a second side plate 21, a top plate 22 and a bottom plate 24 made of sound-absorbing material. Since the first side plate 20 and the second side plate 21 are made of sound-absorbing material, when the sound-absorbing unit 3 adopts the reverse wedge type structure, the two outermost sound-absorbing plates 30 of the sound-absorbing unit 3 can directly use the first side plate 20 and the second side plate 21, thereby saving materials. The two outermost sound-absorbing plates 30 of the sound-absorbing unit 3 are spaced apart from the side plates adjacent thereto. Of course, even when the shell 2 is made of sound-absorbing material, the side plates can not be used as sound-absorbing plates 30. Optionally, when not used, the outermost sound-absorbing plate 30 of the sound-absorbing unit 3 is attached to the side plate adjacent thereto. Since the shell 2 is made of sound-absorbing material, it has certain sound-absorbing and sound-transmitting properties, so the side plates can not have through holes 200. Of course, the through holes 200 can also be provided.

[0197] When the shell 2 is made of sound-absorbing material, the material thereof is preferably the same as that of the sound-absorbing plate 30, and of course can be different. In addition, the thickness of the shell 2 can be the same as or different from that of the sound-absorbing plate 30.

[0198] It can be understood that, with reference to Figure 34b For the reverse wedge type sound-absorbing unit 3, in order to facilitate the distance between the spaced parts, a spacing block 32 can be provided between the adjacent sound-absorbing plates 30 and / or between the sound-absorbing plate 30 and the side plate.

[0199] Optionally, with reference to Figure 35a The anti-reflection device 6 is connected to the ceiling by a first connecting member 61, which can be a wire body, for example, so as to hang the anti-reflection device 6 on the ceiling, or can be a hard structure such as a bolt. With reference to Figure 35b The anti-reflection device 6 can also be connected to the sound barrier 5 by a support member 64, so that it can move together with the sound barrier 5. Obviously, the anti-reflection device 6 can be connected by using both the first connecting member 61 and the support member 64.

[0200] In some embodiments, with reference to Figure 36a The anti-reflection device 6 comprises an anti-reflection plate 60 made of sound-absorbing material, and the material of the anti-reflection plate 60 can be, for example, polyester fiber, glass fiber, rock wool, sponge, foamed metal or melamine foam.

[0201] In some embodiments, with reference to Figure 36bThe anti-reflection device 6 includes two anti-reflection plates 60 made of sound-absorbing materials. The anti-reflection plates 60 can be made of, for example, polyester fiber, glass fiber, rock wool, sponge, foam metal, or melamine foam. The two anti-reflection plates 60 are spaced apart in the height direction and connected by a second connecting member 62. The second connecting member 62 can be a soft wire or a relatively hard component, such as a bolt or a sound-absorbing material block (such as a PET block). The upper anti-reflection plate 60 can be connected to the ceiling using a first connecting member 61. Figure 36c and Figure 36d When the upper and lower anti-reflection plates 60 are connected by a hard second connecting member 62, the position between the two anti-reflection plates 60 can be maintained by the hard second connecting member 62, so that a support member 64 can be used to connect to the sound barrier 5. The type of the support member 64 is not limited, for example, it can be a rod.

[0202] Figure 37 The sound absorption coefficient curves of the anti-reflection device 6 having a single-layer anti-reflection plate 60 and the anti-reflection device 6 having two layers of anti-reflection plates 60 are shown. As can be seen from the figure, the sound absorption coefficient of the single-layer anti-reflection plate 60 will have large peak-to-valley fluctuations as the frequency changes. In the main frequency band of human voice, ranging from 100 to 1000 Hz, the severe peak-to-valley fluctuations will cause the sound insulation performance to decrease in the valley. The sound absorption coefficient of the double-layer anti-reflection plate 60 is significantly higher than that of the single-layer structure. The smooth sound absorption curve helps to achieve stable sound insulation over a wide frequency range.

[0203] In some embodiments, the anti-reflection device 6 includes three or more anti-reflection plates 60 spaced apart along the height direction to further improve the sound insulation effect. The connection structure of two adjacent anti-reflection plates 60 can be referred to above.

[0204] Optionally, when the anti-reflection device 6 includes two or more anti-reflection plates 60, the thickness of the anti-reflection plates 60 is the same, or the thickness of the anti-reflection plates 60 gradually decreases from top to bottom, that is, the thickness of the relatively lower anti-reflection plate 60 is less than the thickness of the relatively upper anti-reflection plate 60. For example, in the case of including two anti-reflection plates 60, the thickness of the lower anti-reflection plate 60 can be less than the thickness of the upper anti-reflection plate 60, so that its impedance is more closely matched with the air impedance, making it easier for sound waves to enter between the two anti-reflection plates 60. Setting the thickness of the upper anti-reflection plate 60 to be relatively larger is conducive to better absorption of sound, thereby improving the effect of preventing sound reflection. At the same time, making one of the anti-reflection plates 60 thinner can reduce the amount of material used, thereby reducing costs. In some embodiments, taking a double-layer anti-reflection plate 60 made of PET material as an example, the PET plate selected is Baijiali's standard plate (density of approximately 210kg / m 3, porosity about 0.97, flow resistivity 74000 Pa·s / m 2 , thermal characteristic length 7.6e-5 m, viscous characteristic length 4.96e-4 m, tortuosity factor 1.02), the thickness of the lower anti-reflection plate 60 can be 4 mm, and the thickness of the upper anti-reflection plate 60 can be 5 mm.

[0205] Optionally, when the anti-reflection device 6 includes two or more anti-reflection plates 60, the distance L1 between the adjacent two anti-reflection plates 60 can be 30-500 mm.

[0206] The thickness of the anti-reflection plate 60 can be set according to its density. Generally, the greater the density of the anti-reflection plate 60, the smaller the thickness can be. For example, when the density of the anti-reflection plate 60 is 360-420 kg / m 3 , the thickness of the bottom plate (i.e., the lowermost anti-reflection plate 60) can be 2-3 mm, and the thickness of the top plate (i.e., the uppermost anti-reflection plate 60) can be 5-6 mm; when the density of the anti-reflection plate 60 is 110-180 kg / m 3 , the thickness of the bottom plate can be 5-7 mm, and the thickness of the top plate can be 9-15 mm. When the density of the anti-reflection plate 60 is 180-230 kg / m 3 , the thickness of the bottom plate (i.e., the lowermost anti-reflection plate 60) can be 3-6 mm, and the thickness of the top plate (i.e., the uppermost anti-reflection plate 60) can be 6-10 mm.

[0207] It can be understood that the anti-reflection device 6 mainly plays a sound-absorbing role, and the above structure is not the only one, as long as it has a broadband sound-absorbing effect. In some embodiments, the anti-reflection device 6 includes sound-absorbing cotton, and the thickness of the sound-absorbing cotton is 50-500 mm.

[0208] In some embodiments, with reference to Figure 35a , the distance L4 between the sound barrier 5 and the anti-reflection device 6 along the height direction is 30-100 cm, and the distance L5 between the anti-reflection device 6 and the ceiling along the height direction is 5-30 cm.

[0209] The two ends of the anti-reflection device 6 extend beyond the two sides of the sound barrier 5 in the width direction, so that it has a more comprehensive anti-reflection effect and makes the mutual interference between the two rooms separated by the sound barrier 5 smaller. Optionally, in the width direction of the sound barrier 5, the ratio of the distance L2 between the two ends of the anti-reflection device 6 and the sound barrier 5 along the horizontal direction is 0.8-1.2, so that the sound barrier 5 has a relatively consistent sound insulation effect on both sides. Further optionally, in the width direction of the sound barrier 5, the distance L2 between the two ends of the anti-reflection device 6 and the sound barrier 5 is the same, i.e., the ratio is 1.

[0210] It can be understood that the length L3 of the anti-diffraction device 6 determines the distance L2 of the two ends of the anti-diffraction device 6 extending out of the sound barrier 5, which will affect the overall sound insulation effect. In order to verify the influence of the length L3 of the anti-diffraction device 6 on the sound insulation effect, simulation tests were carried out in four cases. In the first case, the indoor sound barrier 5 and the anti-diffraction device 6 were not set. In the second to fourth cases, the same sound barrier 5 was set indoors, and the anti-diffraction device 6 with double-layer anti-reflection plate 60 was hung below the ceiling. The difference lies in that the length of the anti-diffraction device 6 is 0.6m, 1.2m and 2.4m respectively. In the four cases, the sound pressure level curve of the sound transmitted by the sound source to the same position was obtained by simulation. Then, the sound pressure level curve in the second to fourth cases was subtracted from the sound pressure level curve in the first case, and the insertion loss curve was obtained, as shown in Figure 38 Figure 38 The curve of the insertion loss when the anti-diffraction device 6 with double-layer anti-reflection plate 60 of different lengths L3 is hung below the ceiling is shown. It can be seen from the figure that the longer the anti-reflection plate 60 is, the better the sound insulation effect is. In order to ensure the anti-reflection effect of the anti-diffraction device 6, the length L3 of the anti-diffraction device 6 is not less than 0.3m. Further, the length L3 of the anti-diffraction device 6 is not greater than 3.6m, so as to reduce the shielding of the ceiling. Optionally, the length L3 of the anti-reflection plate 60 is 2.4m.

[0211] In order to verify the sound insulation effect after using the anti-diffraction device 6 and the sound barrier 5 with the anti-diffraction device 51, simulation tests were carried out in five different cases in a 3.5m high indoor environment. The five different cases are as follows:

[0212] Case 1: as shown in Figure 39a , the sound barrier 5 includes a 3m high and 10cm thick base 50, does not include the anti-diffraction device 51, and does not set the anti-diffraction device 6, and has a 0.5m gap between the sound barrier 5 and the ceiling.

[0213] Case 2: as shown in Figure 39b , the sound barrier 5 includes a 3m high and 10cm thick base 50, does not include the anti-diffraction device 51, and the anti-diffraction device 6 with a single-layer anti-reflection plate 60 is hung below the ceiling with a wire. The length of the anti-reflection plate 60 is 2.4m, and the distance L2 between the two ends of the anti-reflection plate 60 and the sound barrier 5 is the same, and the thickness is 0.9cm.

[0214] Case 3: as shown in Figure 39c ​As shown, the sound barrier 5 includes a 3m high, 10cm thick base 50, does not include a diffraction-preventing device 51, and the anti-reflection device 6 with double-layered anti-reflection plates 60 is hung under the ceiling with a wire, the two layers of anti-reflection plates 60 are parallel and spaced apart, each has a length of 2.4m, and the distance L2 between the two ends and the sound barrier 5 is the same, the upper anti-reflection plate 60 is 0.15m away from the ceiling, and the thickness is 0.8cm, and the lower anti-reflection plate 60 has a thickness of 0.4cm, and the distance L1 between the adjacent two anti-reflection plates 60 along the height direction is 15cm.

[0215] Case 4: As shown in Figure 39d the sound barrier 5 includes a 2m high, 10cm thick base 50, includes a 1m high, 10cm thick diffraction-preventing device 51, and the anti-reflection device 6 with double-layered anti-reflection plates 60 is hung under the ceiling, and the structure and position of the anti-reflection device 6 are the same as those in case 3. The shell 2 of the diffraction-preventing device 51 is made of hard material and is provided with a perforated structure, and the internal sound absorption unit 3 adopts an inverse wedge type (with small cavity) structure. The sound absorption unit 3 includes 7 layers of sound absorption plates 30, and the heights of the 7 layers of plates from left to right are: 1m, 0.7m, 0.5m, 0.2m, 0.5m, 0.7m, 1m, and the thickness of the sound absorption plate 30 is 0.9cm, and the plates are spaced apart by 0.62cm.

[0216] Case 5: No sound barrier 5 and diffraction-preventing device 51 are provided.

[0217] In the above various cases, the materials of the anti-reflection plate 60, the shell 2, and the sound absorption plate 30 are all PET standard plates of Baijiali.

[0218] Figure 40 The insertion loss curves in the four cases are shown in the graph, and the insertion loss curves are obtained by measuring the sound pressure level curves of the sound source received at the same position in the five cases of case 1 to case 5, and then subtracting the sound pressure level curves of case 5 from the sound pressure level curves of case 1 to case 4. Figure 40 As can be seen from the graph, due to the reflection of the ceiling, the sound insulation performance of the single wall is not good as a whole, only 5-10dB, and the average is about 7dB.

[0219] The addition of the anti-reflection device 6 above the sound barrier 5 can significantly increase the overall sound insulation, and the sound insulation performance of the single-layer anti-reflection plate 60 can be seen to have a significant trend with frequency, and the insertion loss can reach 20dB at about 300Hz, and then gradually decreases to 10dB at about 700Hz, and then gradually increases.

[0220] The insertion loss of the double-layer anti-reflection plate 60 is obviously higher than that of the single-layer anti-reflection plate 60, and is more stable, and is more than 20dB as a whole.

[0221] Based on the double-layer anti-reflection plate 60, the sound barrier 5 with the anti-diffraction device 51 is used, and the overall insertion loss can be improved by 3-5dB, which indicates the effectiveness of the anti-diffraction device 51.

[0222] Through the indoor sound insulation structure, the sound insulation performance of the wall body can be increased as much as possible while the wall body is not sealed, so as to meet the comfort and privacy of office workers. Since the sound barrier does not need to be connected to the ceiling, the sound barrier is more convenient to move and disassemble, and the small room does not need to be equipped with complete fire sprinkler and other equipment and measures, which is conducive to reducing the cost.

[0223] The above is only a specific embodiment of the present application, and any improvement made on the basis of the concept of the present application is considered to be within the protection scope of the present application.

Claims

1. An anti-diffraction device, characterized in that: include: A housing (2) comprising a first side panel (20) and a second side panel (21) arranged opposite to each other, and a top panel (22) connected to the tops of the first side panel (20) and the second side panel (21), wherein the first side panel (20) and the second side panel (21) are each provided with one or more through holes (200); and A sound absorbing unit (3) is provided in a cavity (23) formed between the first side panel (20), the second side panel (21) and the top panel (22); the sound absorbing unit (3) is made of a sound absorbing material.

2. The anti-diffraction device according to claim 1, wherein: The sound absorbing unit (3) is in a block shape filled in the cavity (23).

3. The anti-diffraction device according to claim 1, wherein: The width of the sound absorbing unit (3) gradually increases from the top plate (22) toward the side away from the top plate (22).

4. The anti-diffraction device according to claim 3, wherein: The sound absorbing unit (3) is an integrally formed sound absorbing wedge.

5. The anti-diffraction device according to claim 3, wherein: The sound absorbing unit (3) comprises a plurality of sound absorbing panels (30) arranged along the width direction of the housing (2), wherein the heights of the plurality of sound absorbing panels (30) gradually increase from the first side panel (20) and the second side panel (21) toward the middle of the cavity (23), and adjacent two sound absorbing panels (30) are spaced apart or abutted against each other.

6. The anti-diffraction device according to claim 1, wherein: The sound absorbing unit (3) comprises two sound absorbing plates (30) arranged relatively at a distance from each other, the two sound absorbing plates (30) are separated by air, and the sound absorbing plates (30) are made of sound absorbing material.

7. The anti-diffraction device according to claim 6, wherein: The two sound absorbing panels (30) are respectively fitted with the inner walls of the first side panel (20) and the second side panel (21).

8. The anti-diffraction device according to claim 6, wherein: The thickness of the sound absorbing plate (30) is 3 to 36 mm, and the density of the sound absorbing plate (30) is 110 to 420 kg / m 3 .

9. The anti-diffraction device according to claim 8, wherein: The density of the sound absorbing plate (30) is 180-230 kg / m 3 , the thickness of the sound absorbing plate (30) is 6 to 24 mm; The density of the sound absorbing plate (30) is 360-420 kg / m 3 , the thickness of the sound absorbing plate (30) is 3 to 8 mm; The density of the sound absorbing plate (30) is 110-180 kg / m 3 The thickness of the sound absorbing plate (30) is 10 to 36 mm.

10. The anti-diffraction device according to any one of claims 1 to 9, characterized in that: The sound absorbing material is glass fiber, rock wool, sponge, foam metal, polyester fiber or melamine foam.

11. The anti-diffraction device according to any one of claims 1 to 9, characterized in that: The perforation rate of the first side plate (20) and the second side plate (21) is greater than or equal to 15%.

12. The anti-diffraction device according to any one of claims 1 to 9, characterized in that: The top plate (22) seals the top of the housing (2); or, The top plate (22) is provided with a plurality of through holes (200).

13. The anti-diffraction device according to any one of claims 1 to 9, characterized in that: The housing (2) includes a bottom plate (24) connected to the first side plate (20) and the second side plate (21), the top plate (22) and the bottom plate (24) are arranged opposite to each other, and the cavity (23) is formed between the first side plate (20), the second side plate (21), the top plate (22) and the bottom plate (24); or, The anti-diffraction device is used to be installed on the top of the base (50) of the sound barrier, and the cavity (23) is formed between the first side panel (20), the second side panel (21), the top panel (22) and the top surface (500) of the base (50).

14. The anti-diffraction device according to any one of claims 1 to 9, characterized in that: The height of the sound absorbing unit (3) accounts for no less than 90% of the height of the cavity (23); The top of the sound absorbing unit (3) is in contact with the top plate (22) or is spaced apart from the top plate (22).

15. The anti-diffraction device according to any one of claims 1 to 9, characterized in that: The shell (2) is made of sound-absorbing material or hard material.

16. An anti-diffraction device, characterized in that: include: A housing (2) comprising a first side panel (20) and a second side panel (21) arranged opposite to each other, and a top panel (22) connected to the tops of the first side panel (20) and the second side panel (21); and a sound absorbing unit (3) disposed in a cavity (23) formed between the first side panel (20), the second side panel (21), and the top panel (22); The shell (2) and the sound absorbing unit (3) are both made of sound absorbing material.

17. A sound barrier, characterized in that: The device comprises an anti-diffraction device (51) as claimed in any one of claims 1 to 16.

18. The sound barrier according to claim 17, wherein: It also includes a base (50), and the anti-diffraction device is arranged on the top of the base (50); The sound barrier is used outdoors; or The sound barrier is used indoors, and the anti-diffraction device (51) is spaced apart from the ceiling.

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