A micro-gap type adjustable sound absorption device

Abstract

The application discloses a micro-gap type adjustable sound absorption device, which comprises a shell and a partition plate arranged between opposite side walls of an inner cavity of the shell, the partition plate divides the inner cavity of the shell into two cavities; further comprising a rotating plate hingedly arranged at the other end of the partition plate, the rotating plate is matched with the inner cavity structure of the other end of the shell when being perpendicular to the axis of the shell, and the rotating plate does not exceed the other end port when rotating; further comprising two back cavity adjusting components arranged in the two cavities of one end of the shell, the space between the two back cavity adjusting components and the rotating plate is a first back cavity and a second back cavity. Through reasonable setting of the component structure, the inner cavity of the shell is divided into two cavities by the partition plate, and the height of the first back cavity and the second back cavity is adjusted through the two back cavity adjusting components in the two cavities, meanwhile, the rotating plate rotates along the rotating shaft to adjust the gap between the rotating plate and the inner wall of the shell, so that the acoustic reactance and the structural acoustic resistance can be matched with the air impedance at different rotating angles, and the adjustable sound absorption can be realized after the noise frequency band changes, and the structure is simple and convenient to operate.

Description

Technical Field

[0001] This invention belongs to the field of noise control technology, specifically relating to a micro-slit type adjustable sound absorption device. Background Technology

[0002] Sound absorption technology is an important means of noise control, and existing sound absorption mainly relies on traditional sound-absorbing materials (such as porous materials and resonant sound-absorbing materials). While these materials can achieve good sound absorption within a certain frequency range, they also have limitations, such as the inability to adjust the sound absorption frequency band and effect once the material and structure are determined. Application scenarios include noise sources such as engine noise and in-situ mixed noise from acoustic resonance. When the application scenario changes, the existing sound-absorbing materials and structures will be difficult to adapt. Furthermore, for rotating machinery such as engines, where noise frequency changes with rotational speed, traditional sound-absorbing materials alone are unlikely to meet the sound absorption requirements.

[0003] Adjustable sound absorption can adapt to changes in the noise spectrum by rapidly adjusting the structure to obtain a new sound absorption spectrum, giving the sound-absorbing structure a new life. Existing electro / magnetically adjustable sound absorption often utilizes piezoelectric materials and magnetorheological elastomers to create sound-absorbing films, achieving adjustable sound absorption by changing the film tension through electro / magnetism. However, the piezoelectric materials and magnetorheological elastomer films used are difficult to process, and the electromagnetic active control methods are also relatively complex, posing certain difficulties in practical applications. Therefore, to overcome these shortcomings, it is necessary to develop a new adjustable sound absorption structure. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a micro-slit type adjustable sound absorption device. Through the rational arrangement of the component structure, the partition divides the inner cavity of the shell into two chambers, and the height of the first and second back chambers can be adjusted by two back chamber adjustment components within the two chambers. At the same time, the rotating plate rotates along its rotation axis to adjust the gap between the rotating plate and the inner wall of the shell, so that the acoustic impedance and structural acoustic resistance can be matched with the air impedance at different rotation angles. Adjustable sound absorption is achieved after the noise frequency band changes. The structure is simple and easy to operate.

[0005] To achieve the above objectives, the technical solution adopted by the present invention includes:

[0006] A micro-slit type adjustable sound absorption device includes a housing, which is a cylindrical structure with open ends, hollow interior, and rectangular cross-section; it also includes a partition between opposite side walls of the housing cavity, the partition being parallel to the housing axis and dividing the housing cavity into two chambers, with one end of the partition located at one end of the housing and a space between the other end of the partition and the other end of the housing; it also includes a rotating plate hinged to the other end of the partition, the rotating plate's axis of rotation coinciding with the partition and perpendicular to the housing axis, the rotating plate matching the structure of the other end of the housing cavity when perpendicular to the housing axis, and the rotating plate not exceeding the other end of the housing cavity when rotating; it also includes two back cavity adjustment components disposed in the two cavities at one end of the housing, the space between the two back cavity adjustment components and the rotating plate being the first back cavity and the second back cavity, respectively.

[0007] Furthermore, it also includes a rotating plate adjustment unit connected to the rotating plate.

[0008] Preferably, the rotating plate adjustment unit includes a hinge shaft that hinges the rotating plate to the other end of the partition. One end of the hinge shaft extends from the inside to the outside through the side wall of the housing and is connected to a rotation adjustment pointer. The rotation axis of the rotation adjustment pointer is coaxial with the axis of the hinge shaft. The rotating plate adjustment unit also includes an angle adjustment tooth located on the outer side wall where the hinge shaft extends through the housing. The rotation adjustment pointer is in mechanical contact with the angle adjustment tooth.

[0009] Preferably, the contact section between the hinge shaft and the rotating plate is cylindrical, the cross-section of the end of the hinge shaft located on the outside of the housing is polygonal, and the connection between the rotation adjustment pointer and the hinge shaft is provided with a first groove that matches the structure of one end of the hinge shaft.

[0010] Preferably, the back cavity adjustment assembly includes two push-pull plates located in two cavities at one end, the push-pull plates matching the structure of the cavity, and the space between the two push-pull plates and the rotating plate respectively forming the first back cavity and the second back cavity; it also includes a push-pull rod connected to the push-pull plates, the push-pull rod extending toward one end of the housing.

[0011] Furthermore, it also includes slide rails located on opposite sidewalls of the two cavities. The slide rails are parallel to the axis of the housing, and the contact surface between the push-pull plate and the slide rail is provided with a second groove that matches the slide rail structure.

[0012] Preferably, the partition is perpendicular to the opposite sidewall of the housing.

[0013] Preferably, the cross-sections of the first back cavity and the second back cavity are rectangles of equal size.

[0014] Preferably, the rotation angle θ of the rotating plate is 6°–10°, where θ refers to the angle between the rotating plate and the perpendicular plane of the housing axis.

[0015] Preferably, the height of the first back cavity and the second back cavity is 20mm, 30mm, 40mm or 50mm, wherein the height of the back cavity refers to the vertical distance from the lowest point of the rotating plate in the back cavity to the push-pull plate.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] (1) The present invention provides a micro-slit type adjustable sound absorption device. Through the reasonable arrangement of the component structure, the partition divides the inner cavity of the shell into two cavities, and the height of the first back cavity and the second back cavity are adjusted by the two back cavity adjustment components in the two cavities. At the same time, the rotating plate rotates along its rotation axis to adjust the gap between the rotating plate and the inner wall of the shell, so that the acoustic impedance and structural acoustic resistance can match the air impedance at different rotation angles. Adjustable sound absorption is achieved after the noise frequency band changes. The structure is simple and the operation is convenient.

[0018] (2) The micro-slit type adjustable sound absorption device of the present invention, through the reasonable setting of the component structure, does not need to redesign the structure after the noise frequency band changes. It can be achieved simply by rotating the rotating plate and adjusting the back cavity adjustment component. The rotation of the rotating plate can adjust the acoustic impedance of the structure separately, and the up and down movement of the push-pull plate can adjust the acoustic impedance of the structure separately. It can ensure that the structural impedance can match the acoustic impedance at any frequency, and achieve perfect adjustable sound absorption.

[0019] (3) The micro-slit type adjustable sound absorption device of the present invention, through the reasonable setting of the component structure, the height of the first back cavity 9 and the second back cavity 10 are both 20mm. When the rotation angle θ of the rotating plate 6 is adjusted to 6°, 8° and 10°, the sound absorption bandwidth and sound absorption coefficient have changed significantly, which reflects the adjustable function. At the same time, when the rotation angle θ of the rotating plate 4 is 6°, the acoustic impedance of the structure is matched with the air acoustic impedance, and a near-perfect sound absorption effect is achieved at 1300Hz. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the cooling device for an in-situ mixer and the acoustic resonance in-situ mixing system of the present invention.

[0022] Figure 2 for Figure 1 A frontal cross-sectional view;

[0023] Figure 3 This is a graph showing the change in sound absorption coefficient after adjusting the angle of the rotating plate in the embodiment.

[0024] Figure 4 This is a graph showing the change in sound absorption coefficient after adjusting the size of the first back cavity in the embodiment;

[0025] Figure 5This is a graph showing the change in sound absorption coefficient after the dimensions of the first and second back cavities in the embodiment are adjusted simultaneously. The labels in the graph represent:

[0026] 1. Housing; 2. Partition; 3. Push-pull plate; 4. Push-pull rod; 5. Slide rail; 6. Rotating plate; 6-1. Hinge shaft; 7. Rotation adjustment pointer; 8. Angle adjustment gear; 9. First back cavity; 10. Second back cavity. Detailed Implementation

[0027] The invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of this invention.

[0028] It should be noted that the directional terms mentioned in this document, such as "upper end", "lower end", and "outer periphery", are consistent with the specific directions on the paper in the accompanying drawings or the corresponding directions of the space shown in the drawings; all components and devices in this invention, unless otherwise specified, are components and devices known in the prior art.

[0029] Example 1

[0030] like Figure 1 and Figure 2 As shown, this embodiment discloses a micro-slit type adjustable sound absorption device, including a housing 1, which is a cylindrical structure with open ends, hollow interior, and rectangular cross-section; it also includes a partition 2 disposed between opposite side walls of the inner cavity of the housing 1, the partition 2 being parallel to the axis of the housing 1 and dividing the inner cavity of the housing 1 into two cavities, one end of the partition 2 being located at one port of the housing 1, and a space being left between the other end of the partition 2 and the other port of the housing 1; it also includes a rotating plate 6 hinged to the other end of the partition 2, the axis of rotation of the rotating plate 6 being coincident with the partition 2 and perpendicular to the axis of the housing 1, the rotating plate 6 matching the inner cavity structure of the other end of the housing 1 when perpendicular to the axis of the housing 1, and the rotating plate 6 not exceeding the other port of the housing 1 when rotating; it also includes two back cavity adjustment components disposed in the two cavities at one end of the housing 1, the space between the two back cavity adjustment components and the rotating plate 6 being a first back cavity 9 and a second back cavity 10;

[0031] Its function is as follows: the housing 1 is used to support the entire micro-slit adjustable sound absorption device. When the rotating plate 6 rotates, it does not exceed the other end of the housing 1. This means that when the rotating plate 6 rotates at a 90° angle, its highest point does not exceed the outer edge of the other end of the housing 1. When the rotating plate 6 rotates to a position that is not perpendicular to the axis of the housing 1, a gap is formed between the rotating plate 6 and the inner wall of the housing 1. The rotation angle of the rotating plate 6 refers to the angle between the rotating plate 6 and the vertical plane of the axis of the housing 1. The partition 2 divides the inner cavity of the housing 1 into two cavities. When in use, the other end of the housing 1 faces the noise source. The height of the first back cavity 9 and the second back cavity 10 are adjusted by the two back cavity adjustment components in the two cavities. At the same time, the rotating plate 6 rotates along its rotation axis to adjust the size of the gap between the rotating plate 6 and the inner wall of the housing 1, so that the acoustic impedance and structural acoustic resistance can match the air impedance at different rotation angles. Adjustable sound absorption is achieved after the noise frequency band changes. The structure is simple and easy to operate.

[0032] In this embodiment, the dimensions of the shell 1 are L*W*H = 33mm*33mm*100mm, where L, W, and H are the length, width, and height of the shell 1, respectively; the thickness of the rotating plate 6 is between 1mm and 10mm, and is preferably 2mm in this embodiment.

[0033] In this embodiment, the partition 2 is perpendicular to the opposite sidewall of the housing 1, and the cross-sections of the first back cavity 9 and the second back cavity 10 are rectangles of equal size.

[0034] In this embodiment, the preferred rotation angle θ of the rotating plate 6 is 6°, 8° and 10°, where θ refers to the angle between the rotating plate 6 and the perpendicular plane of the axis of the housing 1.

[0035] Specifically, it also includes a rotating plate adjustment unit connected to the rotating plate 6; its function is to adjust the rotation angle of the rotating plate 6 along its axis.

[0036] In a preferred embodiment, the rotating plate adjustment unit includes a hinge shaft 6-1 that hinges the rotating plate 6 to the other end of the partition 2. One end of the hinge shaft 6-1 extends outward from the inside to the outside of the side wall of the housing 1 and is connected to a rotation adjustment pointer 7. The rotation axis of the rotation adjustment pointer 7 is coaxial with the axis of the hinge shaft 6-1. The rotating plate adjustment unit also includes an angle adjustment tooth 8 located on the outer side wall of the housing 1 where the hinge shaft 6-1 extends outward. The rotation adjustment pointer 7 is in mechanical contact with the angle adjustment tooth 8.

[0037] Its function is as follows: the angle adjustment teeth 8 are evenly distributed on the side of the outer shell 1 in an arc. The size of each tooth of the angle adjustment teeth 8 is the same as the tip of the rotary adjustment pointer 7. The mechanical contact between the rotary adjustment pointer 7 and the angle adjustment teeth 8 means that the rotary adjustment pointer 7 rubs against the angle adjustment teeth 8 when it rotates. After the angle is adjusted, the tip of the rotary adjustment pointer 7 is always stuck in the tooth groove of the angle adjustment teeth 8. The rotation of the rotary adjustment pointer 7 can drive the rotating plate 6 to rotate around its axis. When it rotates to the specified angle (that is, the rotation angle of the rotary adjustment pointer 7 is the same as the rotation angle of the rotating plate 6), the rotary adjustment pointer 7 is locked into the tooth groove of the angle adjustment teeth 8 to complete the fixation. The rotation angle of the rotating plate 6 can be determined by counting the number of teeth that deviate from the center position.

[0038] In this embodiment, the preferred rotation angle of each tooth groove of the angle adjustment tooth 8 is 2°.

[0039] In this preferred embodiment, the contact section between the hinge shaft 6-1 and the rotating plate 6 is cylindrical, the cross-section of the end of the hinge shaft 6-1 located outside the housing 1 is polygonal, and the connection between the rotary adjustment pointer 7 and the hinge shaft 6-1 is provided with a first groove that matches the structure of one end of the hinge shaft 6-1.

[0040] Its function is as follows: Since the end section of the hinge shaft 6-1 is polygonal and is engaged with the first groove, when the rotation adjustment pointer 7 rotates, the hinge shaft 6-1 rotates at the same angle, thereby rotating the rotating plate 6 at the same angle to adjust the rotation angle of the rotating plate 6.

[0041] Specifically, the back cavity adjustment assembly includes two push-pull plates 3 located in two cavities at one end. The push-pull plates 3 are matched with the structure of the cavity. The space between the two push-pull plates 3 and the rotating plate 6 is the first back cavity 9 and the second back cavity 10. It also includes a push-pull rod 4 connected to the push-pull plates 3, which extends towards one end of the housing 1. It also includes a slide rail 5 provided on the opposite sidewalls of the two cavities. The slide rail 5 is parallel to the axis of the housing 1, and the contact surface between the push-pull plates 3 and the slide rail 5 is provided with a second groove that matches the structure of the slide rail 5.

[0042] Its function is to adjust the height of the first back cavity 9 and the second back cavity 10 by pushing and pulling the push-pull rod 4 to drive the two push-pull plates 3 to slide along the slide rail 5.

[0043] In this embodiment, the push-pull plate 3 is interference-fitted with the inner wall of the housing.

[0044] In this embodiment, the distance between the plane of the end of the slide rail 5 near the other port of the housing 1 and the rotating shaft of the rotating plate 6 is 20mm ± 0.5mm. The heights of the first back cavity 9 and the second back cavity 10 are 20mm, 30mm, 40mm or 50mm, where the height of the back cavity refers to the vertical distance from the lowest point of the rotating plate 6 in the back cavity to the push-pull plate 3.

[0045] Example 2

[0046] This embodiment uses conventional finite element simulation software to simulate and calculate the sound absorption coefficient of Example 1.

[0047] like Figure 3 As shown, the height of the first back cavity 9 and the second back cavity 10 of the micro-slit adjustable sound absorption device disclosed in Example 1 is 20mm. When the rotation angle θ of the rotating plate 6 is adjusted to 6°, 8° and 10°, the sound absorption bandwidth and sound absorption coefficient change significantly, demonstrating the adjustable function. At the same time, when the rotation angle θ of the rotating plate 4 is 6°, the acoustic impedance of the structure matches the acoustic impedance of the air, achieving a near-perfect sound absorption effect at 1300Hz.

[0048] like Figure 4 As shown, in Example 1, the rotation angle θ of the rotating plate 4 is 6°, while the second back cavity 10 maintains a height of 20mm. When the first back cavity 9 is adjusted to 20mm, 30mm and 40mm, the high-frequency sound absorption effect remains basically unchanged, the low-frequency sound absorption effect is significantly enhanced, and the sound absorption bandwidth is expanded by 200Hz.

[0049] like Figure 5 As shown, the rotation angle θ of the rotating plate 4 in Example 1 is 6°. When the first back cavity 9 and the second back cavity 10 are adjusted to 20mm, 30mm, 40mm and 50mm respectively, the sound absorption frequency band shifts to the low frequency by about 650Hz, and the adjustable sound absorption effect is obvious.

[0050] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0052] Furthermore, the various implementation methods disclosed in this solution can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content invented by this disclosure.

Claims

1. A microslit type tunable sound absorption device, characterized by, The utility model provides a kind of back cavity adjusting device, including shell (1), the shell (1) is open both ends, hollow inside and its cross section is rectangular column structure; Further comprising the partition (2) between the opposite side walls of the inner cavity of shell (1), the partition (2) is parallel to the axis of shell (1), and the partition (2) divides the inner cavity of shell (1) into two cavities, one end of the partition (2) is located in one end of shell (1), and the other end of the partition (2) is spaced from the other end of shell (1); Further comprising the rotating plate (6) hinged at the other end of the partition (2), the rotating shaft of the rotating plate (6) coincides with the partition (2) and is perpendicular to the axis of shell (1), the rotating plate (6) matches the inner cavity structure of the other end of shell (1) when it is perpendicular to the axis of shell (1), and the rotating plate (6) does not exceed the other end of shell (1) when it rotates. Further comprising two back cavity adjusting components arranged in the two cavities at one end of shell (1), and the space between the two back cavities (9) and (10) is respectively the first back cavity (9) and the second back cavity (10). The back cavity adjusting component includes two push-pull plates (3) arranged in the two cavities at one end, and the push-pull plates (3) match the cavity structure, and the space between the two push-pull plates (3) is respectively the first back cavity (9) and the second back cavity (10). Further comprising a push-pull rod (4) connected with the push-pull plate (3), and the push-pull rod (4) extends to the port at one end of shell (1).

2. The microslot tunable absorber of claim 1, wherein, Further comprising a rotating plate adjusting unit connected with the rotating plate (6).

3. The microslot tunable absorber of claim 2, wherein, The rotating plate adjusting unit includes a hinge shaft (6-1) for hinging the rotating plate (6) at the other end of the partition (2), one end of the hinge shaft (6-1) penetrates the side wall of shell (1) from inside to outside and is connected with a rotating adjusting pointer (7), and the rotating shaft of the rotating adjusting pointer (7) is coaxial with the axis of the hinge shaft (6-1). The rotating plate adjusting unit further comprises an angle adjusting tooth (8) located at the outer side wall of shell (1) penetrated by the hinge shaft (6-1), and the rotating adjusting pointer (7) is in mechanical contact with the angle adjusting tooth (8).

4. The microslot tunable absorber of claim 3, wherein, The contact section of the hinge shaft (6-1) and the rotating plate (6) is a cylinder, one end of the hinge shaft (6-1) located at the outer side of shell (1) is a polygon in cross section, and the connection between the rotating adjusting pointer (7) and the hinge shaft (6-1) is provided with a first groove matched with the structure of one end of the hinge shaft (6-1).

5. The microslot tunable absorber of claim 4, wherein, Further comprising a slide rail (5) arranged in the opposite side walls of the two cavities, the slide rail (5) is parallel to the axis of shell (1), and the contact surface between the push-pull plate (3) and the slide rail (5) is provided with a second groove matched with the structure of the slide rail (5).

6. The microslot tunable absorber of claim 1, wherein, The partition (2) is perpendicular to the opposite side walls of the shell (1) where it is located.

7. The microslot tunable absorber of claim 6, wherein, The cross sections of the first back cavity (9) and the second back cavity (10) are equal rectangular.

8. The microslot tunable absorber of claim 7, wherein, The rotating angle θ of the rotating plate (6) is 6°-10°, wherein θ is the included angle between the rotating plate (6) and the vertical plane of the axis of shell (1).

9. The microslot tunable absorber of claim 5, wherein, The heights of the first back cavity (9) and the second back cavity (10) are 20 mm, 30 mm, 40 mm or 50 mm, wherein the height of the back cavity refers to the vertical distance from the lowest point of the rotating plate (6) in the back cavity to the push-pull plate (3).

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