Low-frequency broadband sound insulation unit with ventilation and heat exchange functions and device thereof

Abstract

The application aims to provide a low-frequency broadband sound insulation unit with ventilation and heat exchange functions, comprising an acoustic resonance cavity, a ventilation adjusting baffle, an elastic pre-tightening film, and a sound absorption rib group, wherein the acoustic resonance cavity comprises an upper cavity, a middle cavity, and a lower cavity from top to bottom, and the inner and outer sides of the acoustic resonance cavity are respectively provided with an inner ventilation hole and an outer ventilation hole; the ventilation adjusting baffle comprises a baffle and an adjusting handle, the adjusting handle is fixed on the baffle, the baffle is installed and constrained on the acoustic resonance cavity through an L-shaped positioning slot, one end of the elastic pre-tightening film is constrained through a film fixing device, and the other end is bonded with the end of the acoustic resonance cavity; and the sound absorption rib group is distributed in the upper cavity and the lower cavity. The application has the advantages of light weight, reliability, small space occupation, etc., can be arranged in a periodic array according to the size of the sound insulation space, has strong applicability, has double functions of sound insulation and heat exchange, and makes up for the disadvantages of deterioration of sound insulation quantity when the traditional sound insulation device has ventilation holes.

Description

Technical Field

[0001] The present invention relates to a sound insulation device, specifically a low-frequency broadband sound insulation device. Background Technology

[0002] Noise control has become a hot topic of concern. Noise control can be carried out from three aspects: noise source, propagation path and receiving end. Sound insulation is a simple and relatively effective method for controlling the noise propagation path and is widely used in people's lives and production.

[0003] Sound insulation utilizes the rigidity of materials to reflect incident sound waves onto sound-insulating components, thus blocking the propagation of sound energy. The main method of sound insulation is to add soundproof enclosures or similar structures along the noise propagation path. The sound insulation effect of traditional sound insulation structures typically depends on the mass density, stiffness, and internal damping dissipation of the sound insulation components. It is generally effective for controlling mid-to-high frequency noise, but its effect on low-frequency noise is not significant. Furthermore, when heat exchange vents are added to the soundproof enclosures of certain power equipment, the sound insulation effect decreases sharply. Therefore, scholars are dedicated to exploring novel composite sound insulation structures. For example, the "Broadband Composite Sound Insulation Structure" (patent number: CN202211304705.3) utilizes multi-layered sound insulation panels to achieve broadband noise attenuation; the "A Local Resonance Type Acoustic Metamaterial Low-Frequency Sound Absorption and Insulation Structure" (patent number: CN202111319270.5) is based on the principle of local resonance, uniformly embedding several scatterers within an elastic column to achieve broadband noise reflection; and the "Acoustic Metamaterial Composite Structure Sound Insulation Cover" (patent number: CN202220005105.6) designs a multi-layered thin-film acoustic metamaterial panel, utilizing the acoustic impedance design between the multi-layered acoustic metamaterials to achieve low-frequency broadband sound insulation. Currently, most new sound insulation structures utilize phonon crystals, acoustic metamaterials, and other structures, achieving certain sound insulation effects. However, they still have limitations in low-frequency noise control, and few studies comprehensively consider the low-frequency broadband noise reduction and ventilation / heat exchange functions of sound insulation devices. Summary of the Invention

[0004] The purpose of this invention is to provide a low-frequency broadband sound insulation unit and device that overcomes the limitations of existing technologies in low-frequency sound insulation control while achieving ventilation and heat exchange in the sound insulation structure.

[0005] The objective of this invention is achieved as follows:

[0006] This invention discloses a low-frequency broadband sound insulation unit with both ventilation and heat exchange functions, characterized by comprising an acoustic resonant cavity, a ventilation regulating baffle, an elastic pre-tightening membrane, and a group of sound-absorbing ribs. The acoustic resonant cavity includes an upper cavity, a middle cavity, and a lower cavity from top to bottom. Inner and outer ventilation holes are respectively opened on the inner and outer sides of the acoustic resonant cavity. The ventilation regulating baffle includes a baffle and an adjusting handle, with the adjusting handle fixed to the baffle. The baffle is installed and constrained on the acoustic resonant cavity via an L-shaped positioning groove. One end of the elastic pre-tightening membrane is constrained by a membrane fixing device, and the other end is bonded to the end of the acoustic resonant cavity. The group of sound-absorbing ribs is distributed in the upper and lower cavities, with ribs evenly spaced and their heights increasing sequentially. The maximum height is lower than the plane of the elastic pre-tightening membrane. A perforated plate structure is connected to the top of each rib.

[0007] The present invention may also include:

[0008] 1. An air vent is installed at the outer air vent. The surface of the air vent has 12×6 small round holes and two miniature handrails are attached to it.

[0009] 2. Two strip-shaped mass plates are symmetrically fixed on the surface of the elastic pre-tightened film, and the length of the strip-shaped mass plates is the same as the length of the film.

[0010] 3. The membrane fixing device includes an L-shaped beam structure and a pressure plate. The pressure plate is located on the L-shaped beam structure. Three cylindrical through holes are evenly distributed on the surface of the pressure plate. Three long slot through holes are evenly distributed on the surface of the L-shaped beam structure. The two ends of the L-shaped beam structure are fixed to the inner surface of the acoustic resonance cavity. The elastic pre-tightened membrane is fixed on the L-shaped beam structure by the pressure plate and bolts. The pre-tightening adjustment of the membrane structure is achieved by sliding the position of the pressure plate.

[0011] 4. Two drainage holes are opened at the outer side of the ventilation holes at the top and bottom of the upper and lower cavities.

[0012] The present invention provides a low-frequency broadband sound insulation device that also has ventilation and heat exchange functions, characterized in that: the aforementioned low-frequency broadband sound insulation units that also have ventilation and heat exchange functions are arranged periodically.

[0013] The advantages of this invention are as follows: The low-frequency broadband sound insulation device described in this invention, which combines ventilation and heat exchange functions, can attenuate incident sound waves over a wide low-frequency band while simultaneously providing ventilation and heat exchange. This invention is lightweight, reliable, and space-saving. Depending on the size of the sound insulation space, the device can be arranged in a periodic array, making it highly adaptable. It possesses both sound insulation and heat exchange functions, overcoming the drawback of traditional sound insulation devices where sound insulation deteriorates due to ventilation openings.

[0014] The pre-tightened membrane structure can effectively reflect sound waves entering the ventilation holes of the sound insulation device. The mass strips attached to its surface can effectively reduce the resonant frequency of the membrane structure, thereby achieving ultra-low frequency sound wave reflection. The sound-absorbing rib group is composed of ribs of different heights, and the air columns between the rib group have rich resonant modes, which can achieve attenuation of mid-to-high frequency broadband noise. Combining the above two design features, this invention can achieve noise attenuation across the entire frequency band.

[0015] Compared to traditional sound insulation materials, this invention achieves better low-frequency noise reduction in a smaller size, while also providing ventilation and heat exchange functions. It is economical, highly reliable, and easy to install. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the sound insulation unit of the present invention;

[0017] Figure 2 This is a schematic diagram of an air exchange regulating baffle.

[0018] Figure 3 This is a schematic diagram of the thin film fixing structure;

[0019] Figure 4 A schematic diagram showing the arrangement of sound insulation units in a periodic manner to form a sound insulation device. Detailed Implementation

[0020] The invention will now be described in more detail with reference to the accompanying drawings:

[0021] Combination Figure 1-4 This invention proposes a low-frequency broadband sound insulation device with both ventilation and heat exchange properties, mainly comprising an acoustic resonant cavity 4 and an internal sound-absorbing structure. The acoustic resonant cavity 4 consists of upper, middle, and lower acoustic cavities. Ventilation holes 3 and 11 are opened on the inner and outer sides of the resonant cavity. The hole diameter can be adjusted by a ventilation regulating baffle 2, the configuration of which is as follows: Figure 2 As shown, it consists of a baffle 2-1 and a long adjustable handrail 2-2. The baffle is constrained to the acoustic resonant cavity 4 by an L-shaped positioning groove. A ventilation grille 8 is installed at the outer ventilation hole 11, its surface having 12×6 small round holes, and two miniature handrails 9 are attached for disassembling the ventilation grille. The internal sound-absorbing structure mainly includes an elastic pre-tightening membrane 5, additional mass strips 6, a group of sound-absorbing ribs 1, and a perforated plate structure 13, such as... Figure 1As shown. The left end of the elastic pre-tightening membrane 5 is constrained by the fixing device 10, and the other end is constrained by the end of the intermediate cavity. Two strip-shaped mass plates 6 are symmetrically fixed to the surface of the pre-tightening membrane structure. The length of the strip-shaped mass plates is the same as the length of the membrane. The sound-absorbing ribs 1 are distributed in the upper and lower cavities. The ribs are evenly distributed and the height of the ribs increases sequentially. The maximum height position should be lower than the plane where the membrane is located. The top of the ribs is connected to the perforated plate structure 13. The membrane fixing structure consists of a pressure plate 10-1, an L-shaped beam 10-2, and bolts and nuts 10-5. Three cylindrical through holes 10-3 are evenly distributed on the surface of the pressure plate, and three long slot through holes 10-4 are evenly distributed on the surface of the L-shaped beam structure. Figure 3 As shown. The two ends of the L-shaped beam 10-2 are fixed to the inner surface of the middle cavity. The membrane structure 5 is fixed to the L-shaped beam 10-2 structure by the pressure plate 10-1 and bolts 10-5. The pre-tightening adjustment of the membrane structure 5 can be achieved by sliding the position of the pressure plate 10-1. Figure 1 In the attached drawing, reference numeral 7 indicates a drain hole; reference numeral 12 indicates an L-shaped positioning groove.

[0022] This invention integrates a thin-film structure and a group of sound-absorbing ribs within a sound insulation device. The length of the thin-film structure can generally be designed to be five times the thickness of the sound insulation device, and the film's extension direction is distributed along the width direction of the sound insulation device. The proposed invention has a compact overall configuration and occupies little space. If the noise source structure is large, the device of this invention can be periodically extended, such as... Figure 4 As shown, this periodically distributed sound insulation structure can be directly applied to building windows, highway sound barriers, diesel engine soundproof enclosures, and other fields, and has broad application prospects.

[0023] Due to the presence of ventilation holes, a large amount of sound waves enters the sound insulation device. The pre-tightened membrane vibrates under the excitation of these sound waves, radiating sound waves upstream and downstream. Ultimately, the sound wave transmitted through the inner ventilation hole 3 is equal to the superposition of the upstream incident sound wave and the sound wave radiated by the vibrating membrane.

[0024]

[0025] Among them, P in For the upstream incident sound wave, P rad The downstream radiated sound wave of the thin film can be expressed as:

[0026]

[0027] In the formula, This represents the modal function along the width of the sound insulation device. , , Let represent air density, the height of the intermediate cavity of the sound insulation device, and the modal sound velocity, respectively. H represents the step function operator, and v is the vibration velocity distribution on the membrane surface. v plays a decisive role in the magnitude of Prad, therefore, the optimal parameters of the membrane, including membrane mass density, Young's modulus, and pretension, can be determined based on the membrane-cavity coupling characteristics to achieve maximum reflection of incident sound waves. Due to the presence of the added mass, the resonant frequency of the membrane structure will shift to lower frequencies overall, and the first order frequency is dominated by the vibration of the mass strip. Therefore, the weight of the mass strip can be designed to improve the low-frequency sound wave reflection capability of the membrane structure. In addition, according to the theory of structural vibration sound radiation, symmetrically vibrating structures radiate lower sound pressure at a distance (i.e., the far-field radiated sound waves of even modes are out of phase, and the sound pressure cancels each other out). Therefore, symmetrically vibrating membrane structures have weak sound wave reflection capability. Introducing added mass can effectively break the symmetrical vibration of the membrane, thereby achieving broadband sound reflection capability. Furthermore, the asymmetrically distributed sound-absorbing rib structure also has a suppressive effect on the symmetrical vibration of the membrane, further promoting the sound reflection capability of the pre-tensioned membrane. The sound-absorbing rib group consists of ribs of varying heights. The local air column heights between two ribs differ, resulting in different local modal frequencies. The resonator frequency composed of ribs and perforated plates can be approximated as...

[0028]

[0029] In the formula, ϕ is the ratio of the perforated plate hole area to the equivalent cavity cross-sectional area, D is the cavity depth, and l is the effective length of the perforated plate hole diameter. When the incident sound wave is at a frequency comparable to that of the resonator, the air oscillates violently, and due to the damping of the system, it will dissipate the sound wave significantly. Since the sound-absorbing rib group consists of ribs with continuously varying heights, the air column between the ribs will oscillate over a wide frequency range, thus achieving broadband dissipation of the incident sound wave.

Claims

1. A low-frequency broadband sound insulation unit that also functions as ventilation and heat exchanger, characterized in that: The system includes an acoustic resonant cavity, a ventilation regulating baffle, an elastic pre-tightening membrane, and a group of sound-absorbing ribs. The acoustic resonant cavity comprises an upper cavity, a middle cavity, and a lower cavity, arranged from top to bottom. Inner and outer ventilation holes are respectively opened on the inner and outer sides of the acoustic resonant cavity. The ventilation regulating baffle includes a baffle plate and an adjusting handle, with the adjusting handle fixed to the baffle plate. The baffle plate is installed and constrained on the acoustic resonant cavity via an L-shaped positioning groove. One end of the elastic pre-tightening membrane is constrained by a membrane fixing device, and the other end is bonded to the end of the acoustic resonant cavity. The group of sound-absorbing ribs is distributed in the upper and lower cavities, with ribs evenly spaced and their heights increasing sequentially. The maximum height is below the plane of the elastic pre-tightening membrane. A perforated plate structure is connected to the top of the ribs. Two strip-shaped mass plates are symmetrically fixed to the surface of the elastic pre-tightening membrane, with the length of the strip-shaped mass plates being the same as the length of the membrane.

2. The low-frequency broadband soundproofing unit with ventilation and heat exchange functions according to claim 1, characterized in that: A ventilation grille is installed at the outer ventilation opening. The surface of the ventilation grille has 12×6 small round holes and two miniature handrails are attached to it.

3. The low-frequency broadband soundproofing unit with ventilation and heat exchange functions according to claim 1, characterized in that: The membrane fixing device includes an L-shaped beam structure and a pressure plate. The pressure plate is located on the L-shaped beam structure, and three cylindrical through holes are evenly distributed on the surface of the pressure plate. Three long slot through holes are evenly distributed on the surface of the L-shaped beam structure. The two ends of the L-shaped beam structure are fixed to the inner surface of the acoustic resonance cavity. The elastic pre-tightened membrane is fixed on the L-shaped beam structure by the pressure plate and bolts. The pre-tightening adjustment of the membrane structure is achieved by sliding the position of the pressure plate.

4. A low-frequency broadband sound insulation unit with ventilation and heat exchange functions according to claim 1, characterized in that: Two drainage holes are opened at the outer side of the ventilation holes at the top and bottom of the upper cavity and the lower cavity.

5. A low-frequency broadband sound insulation device that also functions as ventilation and heat exchanger, characterized in that: The low-frequency broadband sound insulation unit with ventilation and heat exchange functions as described in claim 1 is arranged periodically.

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