A Broadband Sound-Absorbing Structure for a Soft-Film Air Conditioner Compressor

Abstract

This application discloses a broadband sound-absorbing structure for a flexible air conditioning compressor, comprising: multiple sound-absorbing cells arranged in a matrix structure and interconnected at their edges; each sound-absorbing cell forming a sound-absorbing cavity, with sound-absorbing holes corresponding to the surface of each cavity; the sound-absorbing holes in the same row of cells being on the same horizontal line, with the hole diameter gradually changing from one side to the other according to a predetermined size; and the hole walls extending towards the sound-absorbing cavity. The matrix arrangement of the sound-absorbing cells and the gradient hole diameter design constitute a multi-band Helmholtz resonant cavity, meeting broadband sound absorption requirements and expanding the sound absorption frequency band by utilizing the resonant frequency differences of different hole diameters. The regular matrix enhances sound wave scattering, increasing the sound absorption bandwidth by approximately 60% compared to traditional structures. Each sound-absorbing unit is independently edge-connected, making the structure deformable and bendable, allowing it to fit and wrap around curved components, reducing gaps and improving sound absorption performance.

Description

Technical Field

[0001] This utility model belongs to the field of air conditioning compressor technology, and particularly relates to a broadband sound-absorbing structure for a soft-material air conditioning compressor. Background Technology

[0002] Existing noise reduction technologies for air conditioning compressors generally employ porous fiber materials or traditional honeycomb micro-perforated structures, but these have significant drawbacks: Firstly, porous materials have poor sound absorption performance in the low-frequency range, making it difficult to suppress low-frequency single-frequency noise caused by compressor electromagnetic forces, refrigerant pulsation, etc. Secondly, although traditional honeycomb structures can absorb sound through the Helmholtz resonance principle, their pore size and sound-absorbing cell size lack coordinated design (e.g., irregular cell spacing and a single linear relationship between pore size and height), resulting in a narrow sound absorption frequency band, insufficient coverage of high and low frequencies, and a fixed structural arrangement with low sound wave scattering efficiency, failing to meet the requirements for wide-band noise reduction. Furthermore, existing sound-absorbing structures are large surfaces that cannot be bent or have poor bending effects, making them unsuitable for various application scenarios. Utility Model Content

[0003] (I) Purpose of the utility model

[0004] To overcome the above shortcomings, the purpose of this utility model is to provide a flexible air conditioning compressor wideband sound absorption structure to solve the technical problems of insufficient low-frequency sound absorption performance, narrow sound absorption bandwidth leading to insufficient high-frequency and low-frequency coverage, and low sound wave scattering efficiency that cannot meet the wideband noise reduction requirements of existing air conditioning compressor sound absorption structures.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the technical solution provided in this application is as follows:

[0007] A broadband sound-absorbing structure for a soft-feed air conditioner compressor includes: multiple sound-absorbing cells arranged in a matrix structure and connected at their edges, each sound-absorbing cell forming a sound-absorbing cavity inside and a sound-absorbing hole being opened on the surface of each sound-absorbing cavity, the sound-absorbing holes of the same row of sound-absorbing cells being on the same horizontal line and the hole diameter gradually changing from one side to the other according to a predetermined size, and the hole wall of each sound-absorbing hole extending toward the sound-absorbing cavity.

[0008] By using a matrix arrangement of sound-absorbing cells and their aperture gradient design, a multi-band Helmholtz resonant cavity is formed. Utilizing the resonant frequency differences corresponding to different apertures, it covers the wide-frequency sound absorption needs from low to high frequencies, expanding the sound absorption bandwidth. At the same time, the regular matrix arrangement enhances the sound wave scattering effect, increasing the sound absorption bandwidth by about 60% compared to traditional structures. In addition, each sound-absorbing unit adopts an independent edge connection design, giving the overall structure excellent deformability and bending ability, allowing it to closely fit and wrap around the surface of curved parts, effectively reducing gaps and further improving the sound absorption effect.

[0009] In some embodiments, the front edge of each sound-absorbing cell is connected to the adjacent sound-absorbing cells in the same row or the next row, forming an active gap between adjacent sound-absorbing cells;

[0010] This connection method constructs a directional flexible network, enabling the sound-absorbing structure to precisely conform to complex curved surfaces and effectively suppress sound leakage. At the same time, it maintains the regularity of the aperture gradient and the acoustic stability of the Helmholtz resonator under deformation, ensuring consistent broadband sound absorption performance and improving engineering adaptability.

[0011] In some embodiments, the sound-absorbing cells in odd-numbered rows are arranged in a forward direction, and the sound-absorbing cells in even-numbered rows are arranged in a reverse direction. The aperture size of the sound-absorbing cells arranged in a forward direction gradually increases from small to large, while the aperture size of the sound-absorbing cells arranged in a reverse direction gradually decreases from large to small.

[0012] By using a reverse arrangement of odd and even rows, acoustic wave phase difference interference is formed, eliminating the cavity standing wave effect and improving the high-frequency absorption coefficient. At the same time, the bidirectional aperture gradient expands the resonant frequency band coverage, effectively solving the frequency band gap problem of traditional honeycomb structures.

[0013] In some embodiments, the relationship between the width of each sound-absorbing cavity and the corresponding sound-absorbing hole diameter is: W = 10 + SQRT(D), where W is the width of the sound-absorbing cavity, D is the size of the sound-absorbing hole diameter, and SQRT(D) is the square root of the sound-absorbing hole diameter.

[0014] By optimizing the cavity volume through nonlinear mathematical relationships, acoustic impedance gradient matching is achieved, avoiding frequency band overlap caused by traditional linear design, and extending the effective sound absorption frequency band to multiple octaves.

[0015] In some embodiments, the relationship between the wall length of each sound-absorbing hole and its corresponding diameter is: H = D / 0.8, where H is the wall length and D is the diameter of the sound-absorbing hole;

[0016] By establishing a fixed proportional relationship between the aperture and the hole wall length, a collaborative control model for the resonant frequency (f = c / (2π)SQRT(S / (V(L+0.8d))))) is created. This model increases the density of the peak frequency distribution of sound absorption, effectively suppressing the characteristic frequency noise caused by the electromagnetic force of the compressor. Specifically, S: the cross-sectional area of ​​the sound absorption hole (πD) 2 / 4), V: Sound absorption cavity volume (W) 2 ×H, W is the cavity width), L: the length of the hole wall H, d: the hole diameter D.

[0017] In some embodiments, the relationship between the aperture sizes of the sound-absorbing holes in the same sound-absorbing cell is as follows: aperture (D) = 1.371X - 0.2667, where X is the aperture number, D is the aperture size of the sound-absorbing hole (201), and X ≥ 1;

[0018] By designing a nonlinear aperture attenuation formula, continuous coverage of the resonant frequency within the sound-absorbing unit is achieved, which improves the continuity of the sound absorption frequency band compared to an equal-spacing aperture design. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the broadband sound-absorbing structure of the soft-material air conditioner compressor of this utility model;

[0020] Figure 2 This is a front view of the broadband sound-absorbing structure of the soft-material air conditioner compressor of this utility model;

[0021] Figure 3 yes Figure 2 A cross-sectional view along the AA direction;

[0022] Figure 4 This is a rear view of the broadband sound-absorbing structure of the soft-material air conditioner compressor of this utility model;

[0023] Figure 5 This is a schematic diagram of the structure of multiple sound-absorbing cells connected together in the broadband sound-absorbing structure of the soft air conditioner compressor of this utility model;

[0024] Figure 6 This is a front view of multiple sound-absorbing cells connected together in the broadband sound-absorbing structure of the soft air conditioner compressor of this utility model;

[0025] Figure 7 yes Figure 6 Cross-sectional view along the BB direction;

[0026] Figure 8 yes Figure 7 A magnified view of part I in the middle;

[0027] Figure 9 This is a comparison chart of sound absorption coefficient and frequency.

[0028] Figure 10 This is a comparison diagram of different arrangements of sound-absorbing holes and their frequency band coverage.

[0029] Figure label:

[0030] 1. Activity gap; 2. Sound-absorbing unit; 201. Sound-absorbing hole; 202. Hole wall; 203. Sound-absorbing cavity. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this utility model. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of this utility model.

[0032] This utility model provides a broadband sound-absorbing structure for a soft air conditioning compressor, comprising: multiple sound-absorbing cell 2 arranged in a matrix structure and interconnected at their edges, each sound-absorbing cell 2 forming a sound-absorbing cavity 203 inside, and sound-absorbing holes 201 being opened on the surface of each sound-absorbing cavity 203, the sound-absorbing holes 201 of the same row of sound-absorbing cell 2 being on the same horizontal line and the hole diameter gradually changing from one side to the other according to a predetermined size, and the hole wall 202 of each sound-absorbing hole 201 extending toward the sound-absorbing cavity 203.

[0033] Specifically, these sound-absorbing cells 2 are directly connected to adjacent cells 2 in the same or next row through their front edges, forming an active gap 1 between adjacent sound-absorbing cells 2.

[0034] This connection method not only ensures the stability of the structure but also provides the basic flexibility of the entire array. To elaborate on the flexibility of this invention, the edge connections between the sound-absorbing cells 2 need to be emphasized. Since the front edge of each sound-absorbing cell 2 is connected to the adjacent cell 2 (whether in the same row or the next row), this connection is flexible, allowing relative displacement between the sound-absorbing cells 2 under stress. Specifically, when the required sound-absorbing component is a planar structure or only needs to be vertically installed at a predetermined distance, there is no need to bend the sound-absorbing structure. When it needs to be wrapped around an arc-shaped component surface, an external bending force needs to be applied to the matrix structure, allowing the entire array to bend into the required curved shape to adapt to the usage scenarios of curved components. This means that the sound-absorbing unit matrix not only maintains the efficient sound absorption function under a rigid structure but also maintains the aperture gradient characteristics of the sound-absorbing holes 201 in a bent state, ensuring that the acoustic performance is not affected.

[0035] The sound-absorbing unit 2 can be made of a polymer or flexible composite material with sound-absorbing properties and elasticity. These materials provide sufficient flexibility when bent while absorbing sound, preventing the units from falling off or deforming. Therefore, in application scenarios, users can easily bend the entire structure according to actual needs (such as uneven mounting surfaces) without redesigning or cutting the units. This not only improves the product's adaptability and ease of installation but also extends its service life, as the bending process does not damage the integrity of the sound-absorbing holes 201 or sound-absorbing cavities 203.

[0036] This application constructs a microporous resonant system with gradient variations. An acoustic resonant system is formed through a precise combination of geometric parameters. When sound waves are incident... This causes air molecules to oscillate back and forth. Sound waves of a specific frequency resonate with the cavity, causing the gas to generate intense friction at the micropores. According to the Helmholtz resonance principle, the sound wave energy is converted into heat energy.

[0037] Please see Figure 8 The aperture of each sound-absorbing cell 2 follows a specific mathematical relationship with the size of its corresponding cavity: aperture (D) = 1.371X - 0.2667, where X is the serial number of the sound-absorbing hole 201; when the aperture is set to D, the cavity width follows the formula W = 10 + SQRT(D), that is... The formula is used to calculate and determine the diameter, and the conversion relationship between the hole wall length H and the hole diameter is H = D / 0.8. For example, when X = 1, D = 1.1 mm. The corresponding resonant frequency is 80Hz.

[0038] In the specific implementation process, a reverse arrangement strategy of odd and even rows is adopted to achieve wide frequency coverage. For the sound-absorbing cell 2 located in the odd row, the aperture arrangement from left to right shows an increasing trend; the corresponding even row cells adopt the opposite decreasing arrangement. This symmetrical gradient design can generate staggered resonant frequency bands. For example, when the sound-absorbing cells in the odd row are arranged with increasing aperture from left to right, the resulting resonant frequency covers the low-frequency range of 80Hz to 1000Hz; while the sound-absorbing cells in the even row are arranged in reverse (aperture decreasing), and their resonant frequency covers the mid-frequency range of 1000Hz to 3000Hz. After the two are superimposed, the frequency band gap is effectively eliminated through acoustic wave phase difference interference and resonant frequency band complementarity, achieving continuous sound absorption coverage of 80Hz-3000Hz. In addition, by combining the nonlinear design of the sound absorption cavity width formula (W=10+SQRT(D)) and the ratio of aperture wall length (H=D / 0.8), the acoustic impedance matching characteristics of the high-frequency range (3000Hz-8000Hz) are further optimized. The aperture gradient expands the frequency response range of the Helmholtz resonator, while the square root relationship of the cavity width enhances the scattering efficiency of high-frequency sound waves. Experimental results show that the structure has an absorption coefficient ≥0.5 in the 80–300Hz range and remains ≥0.75 in the high-frequency range (3000–8000Hz). Considering the high-temperature and high-humidity environment inside the compressor compartment, the sound-absorbing structure of this application must be installed at a certain distance from the compressor to avoid the influence of high temperature and oil contamination.

[0039] To further enhance the noise reduction effect, an auxiliary sound-absorbing layer can preferably be stacked on the basic structure. Attached to the outside of the sound-absorbing unit 2, this auxiliary sound-absorbing layer adopts a gradient density design and consists of five layers of basalt fiber felt, each 0.5 mm thick, with fiber diameters of 3 μm, 5 μm, 8 μm, 12 μm, and 15 μm respectively. The layers are bonded together using high-temperature resistant silicone. This layered structure can provide multi-level attenuation for sound waves in different frequency bands. Actual measurements show that the composite structure improves insertion loss by approximately 4.2 dB in the mid-frequency range without significantly increasing the overall structural volume load.

[0040] To verify the sound absorption effect of this application, the traditional honeycomb structure sound absorption structure and the broadband sound absorption structure of this application were tested at multiple frequency points (80Hz, 800Hz, 1000Hz, 2000Hz, 4000Hz, 6000Hz, 8000Hz), and the following test results were obtained. Figure 9 );

[0041] As can be seen from the figure:

[0042] Low frequency range (800-1500Hz): The sound absorption coefficient is significantly improved, from 0.3 in the traditional structure to more than 0.65 in this structure.

[0043] Mid-to-high frequency range (2000-8000Hz): The sound absorption coefficient is over 0.75, with a maximum of 0.88 (4000Hz), and it still maintains excellent performance of 0.82 in the 8000Hz high frequency range.

[0044] Ultra-low frequency band (80-300Hz): The sound absorption coefficient reaches over 0.50, which is significantly better than the traditional structure (<0.20), effectively suppressing the mechanical vibration noise of the compressor.

[0045] Low frequency band (300-1000Hz): The sound absorption coefficient has been increased from 0.25-0.35 in the traditional structure to more than 0.65 in this structure.

[0046] Mid-frequency band (1000-3000Hz): The sound absorption coefficient is stable in the range of 0.72-0.84, completely solving the frequency band gap problem of traditional structures.

[0047] High frequency band (3000-8000Hz): The sound absorption coefficient is over 0.75, reaching a maximum of 0.88 (4000Hz), and still maintains an excellent performance of 0.82 at 8000Hz.

[0048] Sound absorption bandwidth: The sound absorption bandwidth covers 7 octaves (80Hz–8000Hz), which is 600% higher than that of traditional structures.

[0049] To verify the sound absorption effect of the sound-absorbing holes under different arrangement patterns, tests were conducted on traditional honeycomb structures, forward single-gradient arrangements, and odd-even row reverse arrangements in multiple different frequency bands, and the following test results were obtained. Figure 10 Among them, the forward single gradient arrangement and the odd-even row reverse arrangement are the same in structure except for the arrangement method:

[0050] from Figure 10 It can be known that:

[0051] Traditional honeycomb structures have an effective sound absorption frequency range of 100-1800Hz, which cannot meet the wide frequency sound absorption requirements.

[0052] Positive single gradient arrangement: The effective sound absorption frequency range is extended to 80-6000Hz, but the high frequency coverage is still insufficient.

[0053] Odd and even rows are arranged in reverse: through the sound wave scattering effect (Rayleigh scattering model), the effective sound absorption frequency band is extended to 800-8000Hz, achieving wideband coverage.

[0054] The combination of features in the above implementation methods, through systematic optimization of structural parameters and innovative application of materials and processes, has successfully broken through the limitations of traditional sound absorption technology in low-frequency noise reduction. It is particularly noteworthy that the synergistic effect of each technical feature has produced a significant superposition effect. For example, the combination of gradient arrangement structure and weather-resistant materials enables the device to maintain stable broadband noise reduction performance under complex working conditions, which is something that existing technical solutions cannot achieve.

[0055] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within its protection scope. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A broadband sound absorbing structure for a soft air conditioning compressor, characterized by, include: Multiple sound-absorbing cells (2) are arranged in a matrix structure and connected at their edges. Each sound-absorbing cell (2) forms a sound-absorbing cavity (203) inside and a sound-absorbing hole (201) is opened on the surface of each sound-absorbing cavity (203). The sound-absorbing holes (201) of the same row of sound-absorbing cells (2) are on the same horizontal line and the hole diameter gradually changes from one side to the other according to a predetermined size. The hole wall (202) of each sound-absorbing hole (201) extends toward the sound-absorbing cavity (203).

2. The broadband acoustic structure of a soft air-conditioning compressor as claimed in claim 1, wherein, Each of the sound-absorbing cells (2) has its front edge connected to the adjacent sound-absorbing cells (2) in the same row or the next row, forming an active gap (1) between adjacent sound-absorbing cells (2).

3. The broadband acoustic structure of a soft air-conditioner compressor as claimed in claim 1, wherein The sound-absorbing cells (2) located in odd-numbered rows are arranged in a forward direction, and the sound-absorbing cells (2) located in even-numbered rows are arranged in a reverse direction. The aperture size of the sound-absorbing cells (2) arranged in a forward direction gradually increases from small to large, while the aperture size of the sound-absorbing cells (2) arranged in a reverse direction gradually decreases from large to small.

4. The broadband acoustic structure of a soft air-conditioner compressor as recited in claim 1, wherein, The relationship between the width of each sound-absorbing cavity (203) and the corresponding diameter of the sound-absorbing hole (201) is: W = 10 + SQRT(D), where W is the width of the sound-absorbing cavity (203), D is the diameter of the sound-absorbing hole (201), and SQRT(D) is the square root of the diameter of the sound-absorbing hole (201).

5. The broadband acoustic structure of a soft air-conditioner compressor as recited in claim 1, wherein, The relationship between the length of the hole wall (202) and the corresponding hole diameter of each sound-absorbing hole (201) is: H = D / 0.8, where H is the length of the hole wall (202) and D is the size of the hole diameter of the sound-absorbing hole (201).

6. The broadband acoustic structure of a soft air-conditioner compressor as recited in claim 1, wherein, The aperture size relationship of the sound-absorbing holes (201) in the same sound-absorbing cell (2) is: D = 1.371X - 0.2667, where X is the serial number of the sound-absorbing hole (201), D is the aperture size of the sound-absorbing hole (201), and X ≥ 1.

Images