Sound insulation unit structure with adjustable working frequency and ventilation function

Abstract

The invention provides a sound insulation unit structure with adjustable working frequency and ventilation, which comprises a cover plate, a resonance unit and a back cavity, and square ventilation holes are respectively formed in the centers of the cover plate, the resonance unit and the back cavity. Wherein an annular fan-shaped bracket is arranged at the edge of the box-shaped back cavity, the resonance unit is embedded on the bracket, meanwhile, four rectangular through holes are formed in the circumferential side wall of the resonance unit, and the communication state of the resonance unit and the back cavity is adjusted by adjusting the angle of the resonance unit, so that the intrinsic mode of the structure is changed, and the resonance frequency is adjustable. The sound insulation frequency band of the sound insulation unit is wide, meanwhile, the peak noise reduction frequency is adjusted from 670 Hz to 1017 Hz, and the design facilitating ventilation can be conveniently applied to occasions with high circulation requirements.

Description

Technical Field

[0001] This invention relates to the field of noise control, and in particular to a sound insulation unit structure with adjustable operating frequency and ventilation. Background Technology

[0002] With the deepening of urbanization and the continuous growth of the population, noise generated by human activities, such as traffic noise, community noise, and mechanical noise, is becoming increasingly rampant. However, a series of studies have shown that prolonged exposure to high levels of noise can cause discomfort, and excessive environmental noise can even induce diseases such as hypertension, heart disease, and sleep disorders. Therefore, adopting appropriate noise reduction methods is crucial. Noise reduction technology is divided into active noise reduction and passive noise reduction. Active noise reduction technology has not been widely adopted due to the complexity of its equipment and insufficient reliability under harsh conditions. However, with the emergence of acoustic metamaterials in recent years, passive noise reduction technology has flourished. Commonly used units for noise reduction include Helmholtz resonators, micro-perforated plates, Fabry-Pérot resonators, and Mie resonators.

[0003] However, traditional noise reduction units do not consider ventilation, but in some cases, it is necessary to reduce noise while allowing airflow. For example, mechanical soundproof enclosures require good heat dissipation while also demanding high noise reduction. Similarly, the ventilation and noise reduction performance of building windows affects residents' comfort. Furthermore, traditional noise reduction units are designed with a fixed frequency band, while needs can change, leading to some inefficiency. Therefore, it is necessary to propose a sound insulation structural unit that simultaneously possesses ventilation performance and an adjustable operating frequency band. Summary of the Invention

[0004] To ensure that the operating frequency of the sound insulation structure is adjustable while allowing airflow, this invention proposes a sound insulation structure unit with adjustable operating frequency and ventilation. A ventilation channel is established to allow airflow, and the structure of the resonant chamber is altered by rotating the internal structure, thereby changing the intrinsic modes of the chamber's resonance and achieving frequency adjustment.

[0005] The technical solution adopted in this invention is as follows: A sound insulation unit structure with adjustable operating frequency and ventilation includes: a cover plate, a resonant unit, and a bracket; the resonant unit is embedded in the bracket, and the front end face of the resonant unit is in contact with the cover plate.

[0006] Preferably, the cover plate is a square plate with a first square through hole in the center.

[0007] Preferably, the cover plate has an arc-shaped through hole.

[0008] Preferably, the resonant unit is a cylindrical shell with one bottom surface removed, and a second square through hole is opened at the center.

[0009] Preferably, four rectangular through holes are evenly formed on the circumferential sidewalls of the cylindrical shell opposite the four corners of the second square through hole.

[0010] Preferably, a cylindrical slider is provided on one end face of the resonant unit, which cooperates with the arc-shaped through hole to rotate the resonant unit.

[0011] Preferably, the sound insulation unit structure further includes a back cavity, which is a square box-shaped structure with one end face removed, and a third square through hole in the center.

[0012] Preferably, the first square through hole, the second square through hole, and the third square through hole are all the same square shape and are used as ventilation holes.

[0013] Preferably, the bracket is annular and fan-shaped, located at the edge of the back cavity.

[0014] Preferably, the rectangular through hole on the resonant unit in the assembled sound insulation structural unit is fitted with the bracket, and at this time the resonant cavity of the resonant unit is not connected to the cavity formed by the back cavity and the cover plate.

[0015] Preferably, in the assembled sound insulation structural unit, the four rectangular through holes on the resonant unit are aligned with the four corners of the back cavity by rotating the resonant unit. At this time, the resonant chamber of the resonant unit is connected to the chamber formed by the back cavity and the cover plate.

[0016] Preferably, a ventilated sound barrier is formed by tightly fitting multiple sound insulation unit structures around its perimeter.

[0017] Preferably, the cover plate is a square plate structure with a first square through-hole in the center for ventilation. An arc-shaped through-hole is also formed at the top, perpendicularly penetrating the entire thickness of the cover plate, allowing the slider on the resonant unit to extend through it. The junction of the arc-shaped through-hole and the maximum surface of the cover plate is arc-shaped, with a corresponding central angle of 45°. The arc-shaped through-hole engages with the slider on the resonant unit, thereby rotating the resonant unit.

[0018] Furthermore, in the assembled sound insulation unit, the circumferential sidewall of the resonant unit mates with the support of the back cavity, allowing the circumferential sidewall of the resonant unit to snap onto the support of the back cavity, and the front face of the resonant unit to fit against the cover plate. The knob on the resonant unit mates with the arc-shaped through hole on the cover plate, allowing the knob to extend from the arc-shaped through hole on the cover plate, thus rotating the resonant unit. When the angle of the resonant unit is not adjusted by the knob (the rotation angle is defined as 0°), the rectangular through hole on the circumferential sidewall of the resonant unit fits against the annular fan-shaped support at the back cavity position, and the support can completely block the rectangular through hole, meaning that the resonant chamber of the resonant unit is not connected to the cavity formed by the back cavity and the cover plate. When the resonant unit is rotated 45° by the knob, the center position of the rectangular through hole on the sidewall of the resonant unit is opposite to the four corners of the back cavity, and the support cannot completely block the rectangular through hole. At this time, the unblocked area is the largest, maximizing the connection between the circular resonant chamber and the cavity formed by the back cavity and the cover plate.

[0019] Furthermore, the four corners of the square through holes in the cover plate and back plate are aligned with the centers of the four sides of the square boundary of the cover plate (or back plate), meaning the rotational phase difference between the two squares is 45°. All through holes are 60mm × 60mm squares.

[0020] Furthermore, the circular resonant cavity has an inner diameter of 200mm, a wall thickness of 2mm, and a total thickness of 24mm. The four rectangular through-holes on the circumferential sidewalls correspond to angles of 40°. The back cavity is a box-shaped structure measuring 224mm × 224mm × 24mm, with a wall thickness of 2mm. The four annular fan-shaped supports have a wall thickness of 3mm, and each support corresponds to a central angle of 50°. The cover plate has a thickness of 2mm, and the central angle corresponding to the arc-shaped through-hole on top is 45°. Simultaneously, the slider on the corresponding resonant unit is a cylinder with a diameter of 4.5mm and a height of 4.5mm.

[0021] Furthermore, the resonant unit is made of rigid plastic or plexiglass.

[0022] Furthermore, when the resonant unit rotates at 0°, the operating frequency band is 820~1550Hz and the peak noise reduction frequency is 1017Hz. When the resonant unit rotates at 45°, the operating frequency band is 580~1500Hz and the peak noise reduction frequency is 670Hz.

[0023] Furthermore, by arranging identical sound insulation unit structures side by side, a ventilation barrier with adjustable sound insulation operating frequency is formed.

[0024] The beneficial effects of this invention are: This sound insulation structural unit achieves excellent sound insulation while allowing ventilation, and its operating frequency is adjustable. The unit's sound insulation principle is based on the abrupt change in the sound wave conduction cross-section and the impedance mismatch caused by the resonance of the cavity, thereby reflecting most of the sound energy and achieving noise reduction and sound insulation. The frequency response of the structural unit's impedance is related to its intrinsic modes. At a certain frequency, when a certain intrinsic mode of the structural unit is excited, it can exacerbate the impedance mismatch between the unit and the air impedance, resulting in strong sound reflection and achieving the sound insulation effect.

[0025] The operating frequency of this sound insulation structural unit is adjusted as follows: 1. Rotating the resonant unit changes its connection with the back cavity, thus altering the intrinsic modes of the structural unit. When the angle of the resonant unit is not adjusted using the slider (the rotation angle is defined as 0°), the rectangular through-hole on the circumferential sidewall of the resonant unit is in contact with the annular fan-shaped support at the back cavity, meaning the resonant chamber of the resonant unit is not connected to the cavity formed by the back cavity and the cover plate. When the resonant unit is rotated 45° using the knob, the center position of the side cutout of the resonant unit is opposite to the four corners of the back cavity. At this time, the circular resonant chamber is maximally connected to the cavity formed by the back cavity and the cover plate. Compared to the intrinsic frequency at 0° rotation, the resonant frequency of the cavity shifts to a lower frequency at 45° rotation.

[0026] 2. During the rotation of the resonant unit, there is a phase difference between the second square through-hole at the center, the first square through-hole on the cover plate, and the third square through-hole on the back cavity. This means that the amplitude of the abrupt change in the cross-section of the sound wave transmission medium changes during rotation. Thus, the operating frequency is adjusted through these two methods.

[0027] When the resonant unit rotates at 0°, the operating frequency band of the structural unit is 820~1550Hz, and the peak noise reduction frequency is 1017Hz. When the resonant unit rotates at 45°, the operating frequency band is 580~1500Hz, and the peak noise reduction frequency is 670Hz. Simultaneously, within the operating frequency band, the sound wave transmission loss of the unit is greater than 10dB, meaning the transmitted sound energy is only 10% of the incident sound energy. By adjusting the rotation angle of the resonant unit from 0° to 45°, the operating frequency band will shift towards lower frequencies, and the peak frequency response will change from 1017Hz to 670Hz. Attached Figure Description

[0028] Figure 1 An exploded view of the structural unit assembly in one embodiment of this disclosure; Figures 2(a) to 2(c) are unit structure diagrams in one embodiment of the present disclosure, wherein Figure 2(a) is an isometric view of the cover plate, Figure 2(b) is an isometric view of the resonant unit, and Figure 2(c) is an isometric view of the back cavity; Figures 3(a) to 3(c) are assembly diagrams in one embodiment of the present disclosure. Figure 3(a) is a unit assembly diagram, Figure 3(b) is a cavity position diagram when the resonant unit 2 is rotated 0°, and Figure 3(c) is a cavity position diagram when the resonant unit 2 is rotated 45°. Figure 4 This is a schematic diagram of a simulated acoustic waveguide model in one embodiment of the present disclosure. Figure 5 This is a spectrum diagram of the transfer loss of a structural unit in one embodiment of this disclosure; Figure 6 This is a schematic diagram of a ventilable sound barrier in one embodiment of the present disclosure; Figure 7 This is a sound intensity transmission spectrum diagram of a ventilable sound barrier in one embodiment of this disclosure. Detailed Implementation

[0029] The following will refer to the appendix. Figures 1 to 7 Specific embodiments of this disclosure are described in detail. While specific embodiments of this disclosure are shown in the accompanying drawings, it should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0030] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out this disclosure; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of this disclosure. The scope of protection of this disclosure is determined by the appended claims.

[0031] To facilitate understanding of the embodiments of this disclosure, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of this disclosure.

[0032] This disclosure provides a soundproof structural unit with adjustable operating frequency and ventilation, such as Figure 1 As shown, the sound insulation unit structure includes: cover plate 1, resonant unit 2, and back cavity 3.

[0033] As shown in Figure 2(a), the cover plate 1 is a square plate with a first square through hole (first vent 101) at its center for ventilation. The four corners of the first vent 101 are opposite to the four sides of the square boundary of the cover plate 1, meaning the rotational phase difference between the two squares is 45°. Above the first vent 101, an arc-shaped through hole 102 is simultaneously formed, penetrating vertically through the entire thickness of the cover plate, allowing the slider (knob 203) on the resonant unit 2 to extend out from the arc-shaped through hole 102. The junction of the arc-shaped through hole 102 and the maximum surface of the cover plate is arc-shaped, with a corresponding central angle of 45°, facilitating cooperation with the cylindrical slider (knob 203) on the resonant unit 2 to rotate the resonant unit.

[0034] As shown in Figure 2(b), the resonant unit 2 is a cylindrical shell with a second square through hole (second vent 201) at its center. There are four rectangular through holes 202 on the circumferential sidewalls of the cylindrical shell opposite the four corners of the second vent 201. Simultaneously, a cylindrical slider (knob 203) is provided on the front end face of the resonant unit 2. The cylindrical slider can extend from the arc-shaped through hole 102 of the cover plate and cooperate with it to rotate the resonant unit.

[0035] As shown in Figure 2(c), the back cavity 3 is a square box-shaped structure with the front end face removed. Four side-mounted fan-shaped supports 301 are positioned opposite each other along the four sides. These supports are perpendicular to the plane of the cover plate, and their height is the same as the width of the side wall of the resonant unit, serving to support the resonant unit. A square ventilation hole (third ventilation opening 302) is also opened in the center. The four corners of the third ventilation opening 302 are opposite to the four sides of the boundary square of the back cavity 3, meaning the rotational phase difference between the two squares is 45°.

[0036] In one embodiment, as shown in FIG3(a), in the assembled sound insulation structure unit, the sidewall of the resonant unit 2 cooperates with the support 301 of the back cavity, the sidewall of the resonant unit 2 is embedded on the support 301, and the front end face is in contact with the cover plate 1. The cylindrical slider (knob 203) on the resonant unit extends out from the arc-shaped through hole 102 on the cover plate and cooperates with the arc-shaped through hole 102 on the cover plate, thereby adjusting the angle of the resonant unit 2.

[0037] In another embodiment, as shown in FIG3(b), when the angle of the resonant unit 2 is not adjusted by the slider (the rotation angle is defined as 0°), the rectangular through hole 202 on the circumferential sidewall of the resonant unit is in contact with the annular fan-shaped bracket 301 at the back cavity position, that is, the resonant cavity of the resonant unit 2 is not connected to the cavity formed by the back cavity and the cover plate.

[0038] In another embodiment, as shown in FIG3(c), when the resonant unit is rotated 45° by the knob 203, the center position of the rectangular through hole 202 on the circumferential sidewall of the resonant unit is opposite to the four corners of the back cavity 3. At this time, the circular resonant chamber and the chamber formed by the back cavity and the cover plate are connected together to the maximum extent.

[0039] In another embodiment, the ventilation holes (101, 201, 302) are all 60mm × 60mm squares. Further, the inner diameter of the circular resonant cavity is 200mm, the wall thickness is 2mm, and the overall thickness is 24mm. The rectangular through holes (202) on the four side walls correspond to an angle of 40° and a width of 20mm. The back cavity 3 is a box-shaped structure of 224mm × 224mm × 24mm with a wall thickness of 2mm. The four annular fan-shaped supports 301 have a wall thickness of 3mm, each with a central angle of 50° and a height of 20mm. The cover plate 1 is a plate-shaped structure with a thickness of 2mm and a length and width of 224mm. The central angle corresponding to the arc-shaped through hole 102 on top is 45°. Meanwhile, the knob 203 on the corresponding resonant unit is a cylinder with a diameter of 4.5mm and a height of 4.5mm.

[0040] The operating frequency of this sound insulation structural unit is adjusted as follows: 1. Rotating the resonant unit changes its connection with the back cavity, thus altering the intrinsic modes of the structural unit. When the angle of the resonant unit is not adjusted using the slider (the rotation angle is defined as 0°), the rectangular through-hole on the circumferential sidewall of the resonant unit is in contact with the annular fan-shaped support at the back cavity, meaning the resonant chamber of the resonant unit is not connected to the cavity formed by the back cavity and the cover plate. When the resonant unit is rotated 45° using the knob, the center position of the side cutout of the resonant unit is opposite to the four corners of the back cavity. At this time, the circular resonant chamber is maximally connected to the cavity formed by the back cavity and the cover plate. Compared to the intrinsic frequency at 0° rotation, the resonant frequency of the cavity shifts to a lower frequency at 45° rotation.

[0041] 2. During the rotation of the resonant unit, there is a phase difference between the central square ventilation hole and the ventilation holes in the cover plate and back cavity. This means that the amplitude of the abrupt change in the cross-sectional area of ​​the sound wave transmission medium changes during rotation. Thus, the operating frequency is adjusted through these two methods.

[0042] In another embodiment, a pressure acoustics module in the finite element simulation software COMSOL Multiphysics was used to construct, as shown below. Figure 4 Based on the acoustic waveguide model, the transmission loss of a single structural unit at rotation angles of 0° and 45° was calculated. TL The calculation method is as follows: (1) in, t The sound intensity transmission coefficient; I t and I i These are the transmitted sound intensity and the incident sound intensity, respectively. (2) TL To transmit the loss, dB.

[0043] In another embodiment, such as Figure 5 It can be seen that when the resonant unit rotates at 0°, the operating frequency band of the structural unit is 820~1550Hz, and the peak noise reduction frequency is 1017Hz; when the resonant unit rotates at 45°, the operating frequency band is 580~1500Hz, and the peak noise reduction frequency is 670Hz. Simultaneously, within the operating frequency band, the sound wave transmission loss of the unit is greater than 10dB, meaning the transmitted sound energy is only 10% of the incident sound energy. By adjusting the rotation angle of the resonant unit from 0° to 45°, the operating frequency band and peak operating frequency will shift towards lower frequencies.

[0044] In another embodiment, nine sound insulation structural units are joined together side by side to form a structure as shown in the figure. Figure 6 The sound barrier shown is an example of a sound barrier composed of nine sound insulation structural units. The sound intensity transmission coefficient was simulated using the finite element software COMSOL Multiphysics. t ,like Figure 7 As shown, without adjusting the resonant unit, the lowest operating frequency is 815Hz, and it also exhibits good sound insulation within 2000Hz. Furthermore, by adjusting the rotation angle of the resonant unit, the noise level of the sound barrier can be controlled down to 550Hz. Therefore, the sound barrier constructed from this structural unit provides excellent broadband sound insulation, and the operating frequency can be adjusted by changing the rotation angle of the resonant unit.

[0045] The foregoing general description of the invention and its specific embodiments should not be construed as a limitation on the technical solution of the invention. Those skilled in the art, based on the content disclosed in this disclosure, may add, reduce, or combine the disclosed technical features in the foregoing general description and / or specific embodiments (including examples) without departing from the constituent elements of the invention, to form other technical solutions within the scope of protection of this disclosure.

Claims

1. A soundproof unit structure with adjustable operating frequency and ventilation, characterized in that, The sound insulation unit structure includes: a cover plate, a resonant unit, and a bracket; the resonant unit is embedded in the bracket, and one end face of the resonant unit is in contact with the cover plate.

2. The sound insulation unit structure according to claim 1, characterized in that, Preferably, the cover plate is a square plate with a first square through hole in the center.

3. The sound insulation unit structure according to claim 1, characterized in that, The cover plate has an arc-shaped through hole.

4. The sound insulation unit structure according to claim 1, characterized in that, The resonant unit is a cylindrical shell with one bottom surface removed, and a second square through hole is opened at the center.

5. The sound insulation unit structure according to claim 4, characterized in that, The second square through hole has four rectangular through holes evenly distributed on the circumferential sidewalls of the cylindrical shell with opposite corners.

6. The sound insulation unit structure according to claim 3, characterized in that, A cylindrical slider is provided on one end face of the resonant unit, which cooperates with the arc-shaped through hole to rotate the resonant unit.

7. The sound insulation unit structure according to claim 1, characterized in that, The sound insulation unit structure also includes a back cavity, which is a square box-shaped structure with one end face removed, and a third square through hole in the center.

8. The sound insulation unit structure according to claim 7, characterized in that, The bracket is in the shape of a ring fan and is located at the edge of the back cavity.

9. The sound insulation unit structure according to claim 8, characterized in that, In the assembled sound insulation structure unit, the rectangular through hole on the resonant unit fits into the bracket. At this time, the resonant chamber of the resonant unit is not connected to the chamber formed by the back cavity and the cover plate.

10. The sound insulation unit structure according to claim 1, characterized in that, In the assembled sound insulation structure unit, the resonant unit is rotated so that the four rectangular through holes on the resonant unit are aligned with the four corners of the back cavity. At this time, the resonant chamber of the resonant unit is connected to the chamber formed by the back cavity and the cover plate.

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