A wideband sound-absorbing structure for an air conditioner compressor

Abstract

This application discloses a broadband sound absorption structure for an air conditioner compressor, comprising: a carrier; multiple sound-absorbing units arranged in a matrix on the carrier; each sound-absorbing unit having multiple sound-absorbing cavities spaced apart and sound-absorbing holes formed on the surface of each sound-absorbing cavity; multiple sound-absorbing holes of the same sound-absorbing unit being on the same horizontal line and the hole size gradually increasing from one side to the other; and the hole wall of each sound-absorbing hole extending towards the sound-absorbing cavity; through the matrix arrangement of sound-absorbing units and their hole size gradient design, a multi-band Helmholtz resonant cavity is formed, utilizing the resonant frequency difference corresponding to different hole sizes to cover broadband sound absorption requirements from low frequency (80Hz) to high frequency (8000Hz); 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.

Description

Technical Field

[0001] This utility model belongs to the field of air conditioning compressor technology, and particularly relates to a wideband sound-absorbing structure for an 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 unit size lack coordinated design (such as irregular inter-row dimensions 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, leading to low sound wave scattering efficiency and an inability to meet the requirements for wideband noise reduction. Summary of the Invention

[0003] (a) Purpose of the utility model

[0004] To overcome the above shortcomings, the purpose of this utility model is to provide a wideband sound absorption structure for air conditioner compressors, so as 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 requirements of wideband noise reduction.

[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 an air conditioner compressor includes: a carrier; multiple sound-absorbing units arranged in a matrix on the carrier; each sound-absorbing unit has multiple sound-absorbing cavities spaced apart and sound-absorbing holes are opened on the surface of each sound-absorbing cavity; the multiple sound-absorbing holes of the same sound-absorbing unit 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 of each sound-absorbing hole extends toward the sound-absorbing cavity.

[0008] By using matrix-arranged sound-absorbing units and their aperture gradient design, a multi-band Helmholtz resonant cavity is formed. By utilizing the difference in resonant frequency corresponding to different apertures, it covers the wide-band sound absorption requirements from low frequency to high frequency, thus 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.

[0009] In some embodiments, the sound-absorbing units in the odd-numbered rows on the carrier are arranged in the forward direction, and the sound-absorbing units in the even-numbered rows are arranged in the reverse direction. The aperture size of the sound-absorbing units arranged in the forward direction gradually increases from small to large, while the aperture size of the sound-absorbing units arranged in the reverse direction gradually decreases from large to small.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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;

[0014] 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 established. This improves the density of the peak frequency distribution of sound absorption and effectively suppresses the characteristic frequency noise caused by the electromagnetic force of the compressor. Specifically, S: cross-sectional area of ​​the sound absorption hole (πD² / 4), V: volume of the sound absorption cavity (W²×H, where W is the cavity width), L: hole wall length H, and d: aperture D.

[0015] In some embodiments, the relationship between the aperture sizes of the sound-absorbing holes in the same sound-absorbing unit 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;

[0016] 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

[0017] Figure 1 This is a schematic diagram of the broadband sound-absorbing structure of the air conditioner compressor of this utility model;

[0018] Figure 2 This is a schematic diagram of the broadband sound-absorbing structure of the air conditioner compressor of this utility model, after removing a sound-absorbing unit;

[0019] Figure 3 This is a front view of the broadband sound-absorbing structure of the air conditioner compressor of this utility model;

[0020] Figure 4This is a cross-sectional view of the broadband sound-absorbing structure of the air conditioner compressor of this utility model;

[0021] Figure 5 This is a schematic diagram of the front of the sound-absorbing unit in the broadband sound-absorbing structure of the air conditioner compressor of this utility model;

[0022] Figure 6 This is a schematic diagram of the reverse side of the sound-absorbing unit in the broadband sound-absorbing structure of the air conditioner compressor of this utility model;

[0023] Figure 7 This is a cross-sectional view of the sound-absorbing unit in the broadband sound-absorbing structure of the air conditioner compressor of this utility model;

[0024] Figure 8 yes Figure 7 A magnified view of part A in the middle.

[0025] Figure label:

[0026] 1. Carrier; 2. Sound-absorbing unit; 201. Sound-absorbing hole; 202. Hole wall; 203. Sound-absorbing cavity. Detailed Implementation

[0027] 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.

[0028] This utility model provides a wideband sound absorption structure for an air conditioner compressor, comprising: a carrier 1, multiple sound absorption units 2 arranged in a matrix on the carrier 1, each sound absorption unit 2 having multiple sound absorption cavities 203 spaced apart, and each sound absorption cavity 203 having a sound absorption hole 201 on its surface, the multiple sound absorption holes 201 of the same sound absorption unit 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 absorption hole 201 extending toward the sound absorption cavity 203.

[0029] The core of this application lies in constructing 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.

[0030] Please see Figure 8The aperture of each sound-absorbing unit 2 and the size of its corresponding cavity follow a specific mathematical relationship: 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), i.e., W = 10mm + 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=1.1mm, W=10+ ≈11.04mm, corresponding to a resonant frequency of 80Hz.

[0031] Specifically, the sound-absorbing unit 2 is attached to the carrier 1 through an opening on one side. The carrier 1 can be made of a sound-absorbing material, such as polyurethane foam.

[0032] 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 unit 2 located in the odd-numbered rows, the aperture arrangement from left to right shows an increasing trend; the corresponding even-numbered row units adopt the opposite decreasing arrangement. This symmetrical gradient design can generate staggered resonant frequency bands. For example, when the sound-absorbing units in the odd-numbered rows are arranged with increasing apertures from left to right, the resulting resonant frequency covers the low-frequency range of 80Hz to 1000Hz; while the sound-absorbing units in the even-numbered rows 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 the 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.

[0033] 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.

[0034] 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.

[0035]

[0036] From the table above, we can see that:

[0037] 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.

[0038] Mid-to-high frequency range (2000-8000Hz): The sound absorption coefficient is over 0.75, reaching a maximum of 0.88 (4000Hz), and it still maintains excellent performance of 0.82 in the 8000Hz high frequency range.

[0039] 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.

[0040] Low frequency range (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.

[0041] 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.

[0042] High frequency range (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.

[0043] Sound absorption bandwidth: The sound absorption bandwidth covers 7 octaves (80Hz–8000Hz), which is 600% higher than that of traditional structures.

[0044] To verify the sound absorption effect of the sound-absorbing holes in different arrangement patterns, tests were conducted on the traditional honeycomb structure, the forward single-gradient arrangement, and the odd-even row reverse arrangement in multiple different frequency bands. The following test results were obtained. Among them, the forward single-gradient arrangement and the odd-even row reverse arrangement are identical in structure except for the arrangement method:

[0045]

[0046] From the table above, we can see that:

[0047] Traditional honeycomb structures have an effective sound absorption frequency range of 100-1800Hz, which cannot meet the wide frequency sound absorption requirements.

[0048] Positive single gradient arrangement: The effective sound absorption frequency range is extended to 80-6000Hz, but the high frequency coverage is still insufficient.

[0049] 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.

[0050] 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.

[0051] 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 an air conditioner compressor, characterized in that, include: A carrier (1) is provided with a plurality of sound-absorbing units (2) arranged in a matrix structure on the carrier (1). Each sound-absorbing unit (2) is provided with a plurality of sound-absorbing cavities (203) spaced apart, and a sound-absorbing hole (201) is provided on the surface of each sound-absorbing cavity (203). The plurality of sound-absorbing holes (201) of the same sound-absorbing unit (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 sound absorbing structure of claim 1, wherein, The sound-absorbing units (2) on the carrier (1) are arranged in the forward direction in odd-numbered rows and in the reverse direction in even-numbered rows. The pore size of the sound-absorbing units (2) arranged in the forward direction gradually increases from small to large, while the pore size of the sound-absorbing units (2) arranged in the reverse direction gradually decreases from large to small.

3. The broadband sound absorbing structure of 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).

4. The broadband sound absorbing structure of 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).

5. The broadband sound absorbing structure of claim 1, wherein, The aperture size relationship of the sound-absorbing holes (201) of the same sound-absorbing unit (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.

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