Sound production device and electronic equipment
By using a mixture of activated carbon powder and sound-absorbing particles of different particle sizes to fill the loudspeaker, the problem of filling a narrow area is solved, achieving efficient utilization of the rear acoustic cavity space, reducing the resonant frequency, and improving the low-frequency sound effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GOERTEK INC
- Filing Date
- 2025-12-26
- Publication Date
- 2026-05-08
AI Technical Summary
In existing loudspeakers, the particle size of zeolite sound-absorbing particles cannot effectively fill small areas, resulting in wasted space and failing to meet the requirements for low resonant frequencies.
Activated carbon powder and sound-absorbing particles with different particle sizes are mixed as sound-absorbing materials. The particle size of the activated carbon powder is between 5 μm and 100 μm, and the particle size of the sound-absorbing particles is between 150 μm and 1000 μm, forming spherical particles that fill the rear acoustic cavity, increasing the total filling rate to 99%.
It effectively reduces the resonant frequency of the sound-generating device, improving low-frequency sensitivity and low-frequency sound generation effect.
Smart Images
Figure CN122002167A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electroacoustic technology, and specifically relates to a sound-generating device and an electronic device. Background Technology
[0002] In recent years, with the emergence of folding machines, the requirements for the height of miniature speaker modules have become extremely stringent, with more extreme structures and spacing in some structural areas even less than 100 μm. However, the particle size of zeolite sound-absorbing particles currently added to the rear acoustic cavity is all above 200 μm. Therefore, existing zeolite sound-absorbing particles cannot effectively fill these narrow areas, resulting in wasted space in these areas and failing to meet the requirements of the speaker's low resonant frequency F0.
[0003] Therefore, existing speakers still need improvement. Summary of the Invention
[0004] The purpose of this invention is to provide a sound-generating device and an electronic device. The sound-generating device uses a mixture of activated carbon powder and sound-absorbing particles with different particle sizes as sound-absorbing material to fill the rear acoustic cavity. The sound-absorbing particles are spherical particles formed by bonding multiple molecular sieve powder particles. The surface of the activated carbon powder has a hydrophobic structure, and the average particle size D50 of the activated carbon powder is set between 5 μm and 100 μm, while the average particle size D50 of the sound-absorbing particles is between 150 μm and 1000 μm. This allows the activated carbon powder to not only fill the narrow space of the rear acoustic cavity, making full use of this space, but also fill the gaps between the stacked sound-absorbing particles, increasing the total filling rate of the sound-absorbing material in the rear acoustic cavity to 99%. This effectively reduces the resonant frequency F0 of the sound-generating device, improves low-frequency sensitivity, and results in better low-frequency sound generation.
[0005] The first aspect of the present invention provides a sound-generating device, comprising a housing having an internal space, a sound-generating unit disposed within the housing, and a breathable insulating member. The sound-generating unit cooperates with the housing to define a front sound cavity and a rear sound cavity within the internal space of the housing. The rear sound cavity is filled with a sound-absorbing material. The breathable insulating member is used to isolate the sound-absorbing material from the sound-generating unit. The sound-absorbing material includes activated carbon powder and sound-absorbing particles. The sound-absorbing particles are spherical particles formed by bonding multiple molecular sieve powder particles. The average particle size D50 of the sound-absorbing particles is 150 μm to 1000 μm. The surface layer of the activated carbon powder has a hydrophobic structure. The average particle size D50 of the activated carbon powder is 5 μm to 100 μm. The pore size of the breathable insulating member is smaller than the minimum particle size of the activated carbon powder.
[0006] In some embodiments, the filling volume of the activated carbon powder accounts for 4% to 50% of the total volume of the sound-absorbing material, and the filling volume of the sound-absorbing particles accounts for 50% to 96% of the total volume of the sound-absorbing material.
[0007] In some embodiments, the ratio of the average particle size D50 of the sound-absorbing particles to the average particle size D50 of the activated carbon powder is greater than 5.
[0008] In some embodiments, the sound-absorbing particles have a through-pore structure with a pore size of 500 nm to 8000 nm.
[0009] In some embodiments, the sound-absorbing particles are spherical particles formed by bonding an adhesive with multiple molecular sieve powder particles with an average particle size of 0.1 μm to 30 μm.
[0010] In some embodiments, the crystal structure of the molecular sieve powder includes one of the following crystal structures: MFI, MTW, FER, MOR, MEL, CHA, and LTL.
[0011] In some embodiments, the silica-to-alumina ratio of the molecular sieve powder is greater than 10.
[0012] In some embodiments, the hydrophobic structure of the activated carbon powder includes at least one of silane hydrophobic groups, fluorine-containing atom grafted groups, metal oxide hydrophobic layers, graphene layers, and carbon nanotube layers.
[0013] In some embodiments, the water absorption rate of the activated carbon powder is <5%.
[0014] In some embodiments, the activated carbon powder particles have a microporous structure with a pore size of 0.3 nm to 1.8 nm.
[0015] In some embodiments, the specific surface area of the activated carbon powder particles is greater than 1000 m². 2 / g.
[0016] In some embodiments, the activated carbon powder particles may be shaped as one of the following: spherical, near-spherical, ellipsoidal, rod-shaped, cross-shaped, block-shaped, polygonal, or irregular.
[0017] In some embodiments, the air permeability of the breathable insulating element is 500 L / m². 2 .s@20mmH2O~6000 L / m 2 .s@20mmH2O.
[0018] In some embodiments, the material of the breathable insulating component includes one of polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, stainless steel, aluminum, copper, and natural fibers.
[0019] In some embodiments, the breathable insulating element is a woven mesh fabric.
[0020] In some embodiments, the sound-generating unit includes a housing having an internal cavity, the housing having an air outlet communicating with the internal cavity, and a breathable insulating member connecting the housing and blocking the air outlet.
[0021] In some embodiments, the housing includes a first housing and a second housing connected to each other, the first housing and the second housing together forming an internal space of the housing, the first housing having a first mounting groove on the side near the second housing, and the second housing having a second mounting groove on the side near the first housing, the breathable isolation member including a mounting frame and a breathable component disposed in the mounting frame, the opposite sides of the mounting frame being respectively mounted in the first mounting groove and the second mounting groove.
[0022] A second aspect of the present invention also provides an electronic device, the electronic device comprising the sound-generating device described in the first aspect.
[0023] The sound-generating device provided by this invention uses a mixture of activated carbon powder and sound-absorbing particles with different particle sizes as sound-absorbing material to fill the rear acoustic cavity. The sound-absorbing particles are spherical particles formed by bonding multiple molecular sieve powder particles. The surface of the activated carbon powder has a hydrophobic structure, and the average particle size D50 of the activated carbon powder is set between 5 μm and 100 μm, while the average particle size D50 of the sound-absorbing particles is set between 150 μm and 1000 μm. This allows the activated carbon powder to not only fill the narrow space of the rear acoustic cavity and make full use of it, but also fill the gaps between the stacked sound-absorbing particles, increasing the total filling rate of the sound-absorbing material in the rear acoustic cavity to 99%. This effectively reduces the resonant frequency F0 of the sound-generating device, improves the low-frequency sensitivity, and makes the low-frequency sound generation effect of the sound-generating device better.
[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description
[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of the structure of the sound-generating device in some embodiments of the present invention; Figure 2 This is a schematic diagram of the structure of the sound-generating device in some other embodiments of the present invention; Figure 3 The impedance curves of each loudspeaker in the embodiments and comparative examples of the present invention are shown.
[0027] Explanation of reference numerals in the attached figures: 100 - Sound-generating device; 10 - Shell; 11 - First shell; 12 - Second shell; 20 - Voice-producing unit; 30 - Breathable insulation component; 40 - Sound-absorbing material; 41 - Activated carbon powder; 42 - Sound-absorbing particles. Detailed Implementation
[0028] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.
[0029] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.
[0030] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.
[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0032] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0033] In the description of the embodiments of the present invention, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).
[0034] The first aspect of the present invention provides a sound-generating device, combined with Figures 1 to 3 The sound-generating device 100 includes a housing 10 with an internal space, a sound-generating unit 20 disposed within the housing 10, and a breathable isolation component 30. The sound-generating unit 20 cooperates with the housing 10 to define a front sound cavity and a rear sound cavity within the internal space of the housing 10. The rear sound cavity is filled with a sound-absorbing material 40. The breathable isolation component 30 is used to isolate the sound-absorbing material 40 and the sound-generating unit 20. The sound-absorbing material 40 includes activated carbon powder 41 and sound-absorbing particles 42. The sound-absorbing particles 42 are spherical particles formed by bonding multiple molecular sieve powder particles. The average particle size D50 of the sound-absorbing particles 42 is 150 μm to 1000 μm. The surface of the activated carbon powder 41 has a hydrophobic structure. The average particle size D50 of the activated carbon powder 41 is 5 μm to 100 μm. The pore size of the breathable isolation component 30 is smaller than the minimum particle size of the activated carbon powder 41.
[0035] In this embodiment of the invention, the rear acoustic cavity is filled with sound-absorbing material 40. The sound-absorbing material 40 is mainly obtained by mixing activated carbon powder 41 with sound-absorbing particles 42 of different particle sizes. Because the activated carbon powder 41 has a small particle size range, the activated carbon powder 41 can fill the narrow space of the rear acoustic cavity with a spacing of 10 μm to 100 μm, making full use of this narrow space. At the same time, the first molecular sieve powder 41 can also fill the gaps between the stacked sound-absorbing particles 42, so that the total filling rate or total filling rate of the sound-absorbing material 40 in the rear acoustic cavity is increased to 99%, thereby more effectively reducing the resonant frequency F0 of the sound-generating device, improving the low-frequency sensitivity, and making the low-frequency sound generation effect of the sound-generating device better.
[0036] The average particle size D50 of the activated carbon powder 41 provided by this invention is 5 μm to 100 μm. It is understood that when the average particle size D50 of the activated carbon powder 41 is less than 5 μm, a breathable insulating element 30 with a pore size smaller than 5 μm is required, resulting in insufficient air permeability of the breathable insulating element 30 and failing to meet the air permeability requirements. Conversely, when the average particle size D50 of the activated carbon powder 41 is greater than 100 μm, it is impossible to effectively fill or pack the narrow space, resulting in wasted space and failing to meet the requirements of the low resonant frequency F0 of the loudspeaker. The average particle size D50 of the activated carbon powder 41 provided by this invention can be any value within the range of any two values mentioned above, such as 5 μm to 50 μm, or 50 μm to 100 μm, and so on. For example, the average particle size D50 of the activated carbon powder 41 can be one of 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, 42 μm, 45 μm, 48 μm, 50 μm, 52 μm, 55 μm, 58 μm, 60 μm, 62 μm, 65 μm, 68 μm, 70 μm, 72 μm, 75 μm, 78 μm, 80 μm, 82 μm, 85 μm, 88 μm, 90 μm, 92 μm, 95 μm, 98 μm, 100 μm or any value that satisfies the above range.
[0037] The sound-absorbing particles 42 provided by this invention have an average particle size D50 of 150 μm to 1000 μm. It is understood that when the average particle size D50 of the sound-absorbing particles 42 is less than 150 μm, the particle size is small and easily worn by the irregular structures in the rear acoustic cavity, leading to performance failure. Conversely, when the average particle size D50 of the sound-absorbing particles 42 is greater than 1000 μm, the efficiency of gas exchange between the particles and the surrounding environment decreases, preventing the internal molecular sieve particles from effectively performing their function, resulting in material loss and wasting valuable space in the rear acoustic cavity. The average particle size D50 of the sound-absorbing particles 42 provided by this invention can be any value within the range of any two values mentioned above, such as 150 μm to 500 μm, or 500 μm to 1000 μm, and so on. For example, the average particle size D50 of the sound-absorbing particles 42 can be one of 150 μm, 180 μm, 200 μm, 220 μm, 250 μm, 280 μm, 300 μm, 320 μm, 350 μm, 380 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, 1000 μm or any value that satisfies the above range.
[0038] The activated carbon powder 41 provided by this invention has a hydrophobic surface structure. While it is understood that activated carbon surfaces contain a large number of hydrophilic groups such as hydroxyl groups (-OH), these groups easily adsorb moisture in humid environments, leading to pore blockage and reduced sound absorption performance. However, by using chemical grafting, physical coating, and other methods to construct a modified hydrophobic layer on the activated carbon surface that repels water molecules, the surface can be made water-resistant without compromising the sound absorption function of the activated carbon pores, thus ensuring the material's stability under humid conditions.
[0039] In some embodiments, the hydrophobic structure of activated carbon powder 41 includes at least one of silane hydrophobic groups, fluorine-containing atom grafted groups, metal oxide hydrophobic layers, graphene layers, and carbon nanotube layers.
[0040] Specifically, the hydrophobic structure can be a silane hydrophobic group, or it can be understood as containing a silane graft group. Activated carbon can be treated with a silane coupling agent to graft alkyl hydrophobic groups onto the surface, and the resulting activated carbon powder 41 has a hydrophobic effect.
[0041] The hydrophobic structure can be a fluorine-containing graft group, and can be achieved by chemical deposition methods, such as solution impregnation deposition (dispersing activated carbon powder in an alcohol solution containing fluorine silanes, such as an ethanol-water mixture), so that a fluorine silane structure layer is formed on the surface of the activated carbon, thereby obtaining hydrophobic functionality.
[0042] The hydrophobic structure can be a hydrophobic layer of metal oxide, or it can be understood as a metal oxide coating layer. For example, in a vacuum environment, the metal oxide precursor (metal oxides such as aluminum oxide or iron oxide) is vaporized and deposited on the surface of activated carbon to form a hydrophobic layer of metal oxide, which plays a hydrophobic role.
[0043] Hydrophobic structures can be graphene layers, carbon nanotube layers, etc. For example, activated carbon can be calcined at high temperature under oxygen-free conditions to graphitize its surface structure, remove polar groups such as hydroxyl, aldehyde, and carboxyl groups, and reduce water absorption.
[0044] It is worth mentioning that, in order to balance the compatibility between the hydrophobic function of activated carbon powder 41 and the porous sound-absorbing structure, the layer thickness of the hydrophobic structure in this embodiment of the invention can be 0.01 μm to 2 μm, which does not affect the air permeability and adsorption effect and also has hydrophobicity.
[0045] In some embodiments, the filling volume of activated carbon powder 41 accounts for 4% to 50% of the total volume of sound-absorbing material 40, and the filling volume of sound-absorbing particles 42 accounts for 50% to 96% of the total volume of sound-absorbing material 40. It is understood that when the filling volume of activated carbon powder 41 in the rear acoustic cavity is too large, the sound-absorbing material 40 in the rear acoustic cavity will form a more dense accumulation, hindering the overall movement of the sound-absorbing material 40, increasing airflow resistance, and thus affecting the sound absorption effect of the sound-absorbing material 40. Conversely, when the filling volume of activated carbon powder 41 in the sound-absorbing material 40 is too small, the utilization of the rear acoustic cavity volume cannot be maximized, reducing the filling rate of the rear acoustic cavity sound-absorbing material 40. When the activated carbon powder 41 and sound-absorbing particles 42 are designed according to the above volume ratio, the total filling rate of the rear acoustic cavity sound-absorbing material 40 is increased to 99%, achieving efficient utilization of the rear acoustic cavity filling space, significantly improving the filling utilization rate, and more effectively reducing the speaker resonant frequency F0.
[0046] In some embodiments, the combination ratio of activated carbon powder 41 to sound-absorbing particles 42 can be adjusted according to the rear acoustic cavity structure of different sound-generating devices 100 to achieve maximum utilization of the rear acoustic cavity filling. For example, the filling volume of activated carbon powder 41 can be one of the following: 4%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, 50% of the total volume of the sound-absorbing material 40, or any value satisfying the above range. The filling volume of sound-absorbing particles 42 can be one of the following: 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 96% of the total volume of the sound-absorbing material 40, or any value satisfying the above range.
[0047] In some embodiments, the ratio of the average particle size D50 of the sound-absorbing particles 42 to the average particle size D50 of the activated carbon powder 41 is greater than 5. It is understood that when the ratio of the average particle size D50 of the sound-absorbing particles 42 to the average particle size D50 of the activated carbon powder 41 is less than 5, the activated carbon powder 41 cannot fill the gaps formed between the multiple sound-absorbing particles 42, thus affecting the filling amount of the sound-absorbing material 40 in the rear acoustic cavity; when the ratio of their average particle sizes D50 is greater than 5, the activated carbon powder 41 can fully and effectively fill the gaps formed by the sound-absorbing particles 42, achieving efficient utilization of the gap space. For example, the ratio of the average particle size D50 of the sound-absorbing particles 42 to the average particle size D50 of the activated carbon powder 41 can be 6, 6.5, etc., and can be set according to actual conditions.
[0048] In some embodiments, the activated carbon powder particles 41 contain a microporous structure with a pore size of 0.3 nm to 1.8 nm. It is understood that activated carbon powder particles 41 with a microporous structure having a pore size between 0.4 nm and 1 nm can effectively adsorb and desorb air molecules in the air, effectively reducing the resonant frequency F0 of the sound-generating device. Exemplarily, the pore size of the microporous structure in the activated carbon powder particles 41 can be one of 0.3 nm, 0.4 nm, 0.5 nm, 0.6 nm, 0.62 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, and 1.8 nm, or any value satisfying the above range.
[0049] In some embodiments, the activated carbon particles 41 have a pore structure with a pore size of 0.3 nm to 50 nm. It is understood that, in addition to microporous structures with pore sizes between 0.3 nm and 1.8 nm, the activated carbon particles 41 may also have pore structures with other pore sizes, all of which have a pore size within 50 nm. Exemplarily, the pore size of the pore structure in the activated carbon particles 41 can be one of 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 12 nm, 15 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, 45 nm, 48 nm, or 50 nm, or any value satisfying the above range.
[0050] In some embodiments, the shape of activated carbon powder 41 may be, but is not limited to, spherical, near-spherical, ellipsoidal, rod-shaped, cross-shaped, block-shaped, polygonal, or irregular. The appropriate shape of activated carbon powder 41 may be selected according to the actual situation.
[0051] In some embodiments, the activated carbon powder 41 is selected from spherical or near-spherical shapes. When such activated carbon powder 41 is filled with near-spherical sound-absorbing particles 42, it can achieve maximum space packing and filling efficiency. Furthermore, such powder has good flowability, which is beneficial for filling or packing.
[0052] In some embodiments, the specific surface area of the activated carbon powder 41 is greater than 1000 m². 2 / g. It is understandable that when the specific surface area of activated carbon powder 41 is greater than 1000 m²... 2 At a specific surface area of / g, its abundant hierarchical porous structure can effectively enhance the scattering and dissipation of sound waves, thereby significantly improving the acoustic performance of the sound-generating device. However, when the specific surface area of the activated carbon powder 41 is less than 1000 m², its... 2 At a specific surface area of 1500 m² / g, the pores of the low-specific-surface-area activated carbon powder 41 are not sufficiently developed, with a low proportion of micropores and mesopores. This results in a significant reduction in the effective interface for contact with sound waves, making it impossible to fully adsorb and scatter sound wave energy. For example, the specific surface area of the activated carbon powder 41 can be, but is not limited to, 1500 m² / g. 2 / g.
[0053] In some embodiments, the water absorption rate of activated carbon powder 41 is <5%. It is understood that by providing a hydrophobic structure on the surface of activated carbon powder 41, the problem of activated carbon easily absorbing water and failing due to the presence of a large number of hydrophilic groups such as hydroxyl groups (-OH) on its surface can be effectively alleviated. The water absorption rate of activated carbon powder 41 can be less than 5%, ensuring that the sound-generating device maintains its performance in high humidity environments. For example, the water absorption rate of activated carbon powder 41 can be one of 1%, 2.7%, 3%, 3.5%, 3.8%, 4%, 4.5%, or 4.8%, or any value satisfying the above range.
[0054] In some embodiments, the sound-absorbing particles 42 contain a through-pore structure with a pore size of 500 nm to 8000 nm. It can be understood that the sound-absorbing particles 42 contain interconnected macroporous structures, allowing air to enter the interior of the sound-absorbing particles 42 through these macroporous structures. This enables the sound-absorbing powder particles distributed near the center of the particles to fully exert their adsorption and desorption effects on air molecules. Alternatively, it can be understood as effectively utilizing the adsorption and desorption capabilities of the sound-absorbing powder particles deep within the particles near the center, achieving efficient dissipation of sound energy and ultimately reducing the resonant frequency F0 of the sound-generating device. It should be noted that when the pore size of the through-pore structure is less than 500 nm, the speed at which air passes through the channels decreases, making it difficult for air to penetrate the interior of the particles and contact the deep sound-absorbing powder particles, thus hindering the effectiveness of the adsorption-desorption sound energy loss mechanism. Conversely, when the pore size of the through-pore structure is greater than 9000 nm, the overall structure of the particles is relatively loose, making them susceptible to breakage under drop conditions and surface wear, leading to structural damage and performance failure. For example, the aperture of the through-hole structure can be one of 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1200 nm, 1500 nm, 1800 nm, 2000 nm, 2200 nm, 2500 nm, 2800 nm, 3000 nm, 3200 nm, 3500 nm, 3800 nm, 4000 nm, 4200 nm, 4500 nm, 4800 nm, 5000 nm, 5200 nm, 5500 nm, 5800 nm, 6000 nm, 6200 nm, 6500 nm, 6800 nm, 7000 nm, 7200 nm, 7500 nm, 7800 nm, 8000 nm or any value that satisfies the above range.
[0055] In some embodiments, the sound-absorbing particles 42 are spherical particles formed by bonding an adhesive with multiple molecular sieve powder particles with an average particle size D50 of 0.1 μm to 30 μm. This results in the formation of spherical particles that retain the microporous structure of the molecular sieve powder particles, while mesopores and macropores are formed between the molecular sieve powder particles, thus creating a multi-level interconnected channel of "micropores + mesopores + macropores". This structure can significantly increase the contact area between air and molecular sieve powder particles, prolong the residence time of air molecules in the channels, enhance the sound energy loss efficiency of the adsorption-desorption process, and achieve the effect of reducing the resonant frequency F0 of the sound-generating device. For example, the average particle size D50 of the molecular sieve powder can be one of 0.1 μm, 0.2 μm, 0.5 μm, 0.6 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm or any value that satisfies the above range.
[0056] In some embodiments, the molecular sieve particles comprise a microporous structure with a pore size of 0.4 nm to 1 nm. It is understood that the molecular sieve particles, having a microporous structure with a pore size between 0.4 nm and 1 nm, can effectively adsorb and desorb air molecules from the air, effectively reducing the resonant frequency F0 of the sound-generating device. Exemplarily, the pore size of the microporous structure in the molecular sieve particles can be one of 0.4 nm, 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, and 1 nm, or any value satisfying the above range.
[0057] In some embodiments, the shape of the molecular sieve particles may be, but is not limited to, spherical, quasi-spherical, ellipsoidal, rod-shaped, cross-shaped, block-shaped, polygonal, or irregular.
[0058] In some embodiments, the shape of the molecular sieve particles is selected from spherical or near-spherical, and such molecular sieve particles help to bind together to form near-spherical sound-absorbing particles 42.
[0059] In some embodiments, the crystal structure of the molecular sieve powder includes one of the following crystal structures: MFI, MTW, FER, MOR, MEL, CHA, and LTL, which can be selected according to actual needs.
[0060] In some embodiments, the silica-to-alumina ratio of the molecular sieve powder is greater than 10. It should be noted that when the silica-to-alumina ratio of the molecular sieve powder is greater than 10, the proportion of silicon-oxygen tetrahedra in its crystal framework is significantly increased, enhancing the hydrophobicity of the structure and thus providing superior moisture resistance. Conversely, when the silica-to-alumina ratio of the molecular sieve powder is less than 10, under alternating wet and dry conditions, the low silica-to-alumina ratio molecular sieve experiences irreversible expansion and contraction of its framework due to repeated moisture absorption and desorption, resulting in a continuous decline in mechanical properties and making long-term stable service difficult. For example, the silica-to-alumina ratio of the molecular sieve powder can be, but is not limited to, 600.
[0061] In some embodiments, the adhesive includes at least one of organic adhesives and inorganic adhesives.
[0062] Specifically, organic adhesives include one or more of polyacrylates, polyurethanes, and silicones. For example, it could be a polyacrylic acid adhesive.
[0063] Inorganic adhesives include at least one of silicates, silica sols, aluminosilicates, phosphates, sulfates, and borates.
[0064] In some embodiments, the breathable insulating member 30 is used to isolate the sound-absorbing material 40 from the magnetic circuit system of the sound-generating unit 20. This can be understood as isolating the sound-absorbing material 40 from the outside of the magnetic circuit system to prevent the sound-absorbing material 40 from entering the magnetic circuit system.
[0065] In some embodiments, the air permeability of the breathable insulating element 30 is 500 L / m. 2 .s@20mmH2O~6000 L / m 2 .s@20mmH2O. It should be noted that under a pressure of 20 mmH2O, when the air permeability of the breathable insulating element 30 is less than 500 L / m... 2 When the air permeability is .s@20mmH2O, the acoustic impedance of the breathable insulating element 30 is relatively large, affecting the airflow efficiency and causing the resonant frequency F0 of the sound-generating device to increase, thus negatively impacting its acoustic performance. Conversely, if the air permeability of the breathable insulating element 30 is too high, the first molecular sieve particles 41 will leak out and contaminate the sound-generating monomer 20. In this embodiment of the invention, when the air permeability of the breathable insulating element 30 is 500 L / m 2 .S@20mmH2O~6000 L / m 2 When S@20 mmH2O, it can not only effectively encapsulate the sound-absorbing material 40, but also ensure its air permeability. The air permeability of the air-permeable insulating component 30 provided by this invention can be any value within the range formed by any two values in the above range, for example, it can be 500 L / m 2 .S@20 mmH2O~3000 L / m 2 .S@20 mmH2O, or 3000 L / m 2.S@20mmH2O~6000 L / m 2 .S@20 mmH2O, and so on. Exemplarily, in this embodiment of the invention, the air permeability of the breathable insulating element 30 can also be 500 L / m². 2 .S@20 mmH2O, 1000 L / m 2 .S@20 mmH2O, 2000 L / m 2 .S@20 mmH2O, 3000 L / m 2 .S@20 mmH2O, 4000 L / m 2 .S@20 mmH2O, 5000 L / m 2 .S@20 mmH2O, 6000 L / m 2 One of the following: .S@20 mmH2O or any value that satisfies the above range.
[0066] In some embodiments, the material of the breathable insulating component 30 includes one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), polyethylene (PE), stainless steel, aluminum, copper, and natural fibers.
[0067] In some embodiments, the breathable insulating element 30 may be a woven mesh.
[0068] See Figure 1 As shown, the housing 10 includes a first housing 11 and a second housing 12 connected to each other. The first housing 11 and the second housing 12 together form the internal space of the housing 10. The first housing 11 is provided with a first mounting groove on the side near the second housing 12, and the second housing 12 is provided with a second mounting groove on the side near the first housing 11. The breathable isolation component 30 includes a mounting frame and a breathable component disposed in the mounting frame. The opposite sides of the mounting frame are respectively installed in the first mounting groove and the second mounting groove.
[0069] In some embodiments, the material of the breathable component may be, but is not limited to, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), polyethylene (PE), stainless steel, aluminum, copper, and natural fibers.
[0070] In some embodiments, the breathable insulating member 30 can be directly connected to the housing 10 to house the sound-generating unit 20 within the space formed by the breathable insulating member 30, the first housing 11, and the second housing 12. The connection method between the breathable insulating member 30 and the housing 10 can be, but is not limited to, bonding, hot-melt sealing, or injection molding.
[0071] See Figure 2As shown, the sound-generating unit 20 includes a shell with an internal cavity. The shell is provided with an air outlet that communicates with the internal cavity. The breathable isolation component 30 is connected to the shell and blocks the air outlet. In this way, the magnetic circuit system inside the sound-generating unit 20 is isolated from the overall space of the rear acoustic cavity, and the sound-absorbing material 40 can be filled in the entire rear acoustic cavity space.
[0072] In some embodiments, the breathable isolation member 30 is disposed at the sound leakage hole of the sound-generating unit 20, thereby isolating and protecting the magnetic circuit system inside the sound-generating unit 20.
[0073] A second aspect of the present invention provides an electronic device, the key feature of which is that it includes the sound-generating device 100 described in the first aspect.
[0074] In embodiments of the present invention, the electronic device may be, but is not limited to, a mobile phone, a tablet computer, a smartwatch, a game console, a learning machine, etc., and the electronic device has the characteristic of good acoustic performance.
[0075] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; the raw materials, instruments, and equipment used in the following embodiments can all be obtained commercially or through existing methods; unless otherwise specified, the amounts of experimental reagents used are the amounts used in conventional experimental operations; unless otherwise specified, the experimental methods are conventional methods. It should be further noted that the following descriptions are merely exemplary and not intended to limit the specific scope of the invention. Moreover, the comparative examples below are selected to compare with the technical solutions of the present invention to demonstrate the advancement of the present invention, and do not necessarily represent prior art in this technical field.
[0076] It should be noted that the experimental materials used in each embodiment and comparative example are described below.
[0077] 1) Activated carbon powder 41: average particle size D50 is 20 μm, specific surface area is 1500 m². 2 / g, water absorption rate of 2.7%, shape is spherical, activated carbon powder 41 has a microporous structure with a pore size of 0.62 nm.
[0078] It should be noted that the activated carbon powder 41 is treated with the silane coupling agent methyltrimethoxysilane, resulting in silane graft groups on the surface of the activated carbon powder 41. Specifically, the activated carbon powder 41 is dispersed in an ethanol-water mixed solution, the pH is adjusted to 4-5, the silane coupling agent methyltrimethoxysilane is added, and the mixture is stirred at 60°C for 4 hours. The alkoxy groups of the silane coupling agent hydrolyze to generate hydroxyl groups, which undergo dehydration condensation with the hydroxyl groups on the surface of the activated carbon, grafting hydrophobic methylsiloxy groups onto the surface of the activated carbon powder 41.
[0079] The water absorption rate test methods for activated carbon powder 41 include: Take 0.1 g of sample and spread it evenly in a glass petri dish. Then place it on the inner shelf of a desiccator with an inner diameter of 240 mm. Add 200 mL of water to the bottom of the desiccator and seal it in an environment at 25°C. After 24 h, open the desiccator, remove the test sample, and leave it exposed for 20 min before testing the water absorption rate. The formula for calculating the water absorption rate is: Sample water absorption rate = ((sample mass after experiment - sample mass before experiment) / sample mass before experiment) × 100%.
[0080] 2) Sound-absorbing particles 42: These are spherical particles formed by bonding multiple molecular sieve powder particles together with polyacrylic acid adhesive. The molecular sieve powder particles have an MFI crystal structure, a silicon-to-aluminum ratio of 600, an average particle size D50 of 1.5 μm, and an average particle size D50 of 350 μm. The sound-absorbing particles 42 contain a through-pore structure with a pore size of 800 nm.
[0081] 3) Breathable insulating component 30: Made of PET woven mesh with a pore size of 15 μm and an air permeability of 1200 L / m 2 .s@20mmH2O.
[0082] 4) Loudspeaker (sound-generating device 100): Model ZZY15 (see structure) Figure 2 As shown), material 3) PET woven mesh is used to separate the sound-absorbing material 40 in the rear acoustic cavity, and the total filling volume of the rear acoustic cavity is 0.28 mL.
[0083] Example 1 Measure 0.23 mL of material 2) sound-absorbing particles 42 using a measuring cup. The volume of sound-absorbing particles 42 accounts for 85.2% of the total volume of sound-absorbing material 40. Then measure 0.04 mL of material 1) activated carbon powder 41. The volume of activated carbon powder 41 accounts for 14.8% of the total volume of sound-absorbing material 40. Mix the first molecular sieve powder 41 and sound-absorbing particles 42 and fill them into the rear acoustic cavity of the speaker ZZY15 to complete the product manufacturing.
[0084] Example 2 Measure 0.15 mL of material 2) sound-absorbing particles 42 using a measuring cup. The volume of sound-absorbing particles 42 accounts for 65.2% of the total volume of sound-absorbing material 40. Then measure 0.08 mL of material 1) activated carbon powder 41. The volume of activated carbon powder 41 accounts for 34.8% of the total volume of sound-absorbing material 40. Mix activated carbon powder 41 and sound-absorbing particles 42 and fill them into the rear acoustic cavity of speaker ZZY15 to complete the product manufacturing.
[0085] Comparative Example 1 0.23 mL of material 2) sound-absorbing particles 42 were measured using a measuring cup and filled into the rear acoustic cavity of speaker ZZY15 to complete the product manufacturing.
[0086] It is worth mentioning that, according to the experimental test, when the rear acoustic cavity of the speaker ZZY15 was filled with sound-absorbing particles 42 (material 2) to the point of overflow, the total filling volume of the sound-absorbing particles 42 was calculated to be 0.23 mL. Although there was still 0.05 mL of space, the sound-absorbing particles 42 could not be filled any further, and the filling rate of the rear acoustic cavity was 82.1%.
[0087] Performance testing (a) Impedance (IMP) Test After the speakers in the above embodiments and comparative examples were manufactured, the impedance (IMP) of each speaker was tested using SoundCheck software and a speaker testing system to obtain the impedance curves and resonant frequency F0 of each speaker. (See [link to relevant documentation]). Figure 3 As shown.
[0088] Meanwhile, the filling parameters of the loudspeakers and the resonant frequency F0 of the loudspeakers in the embodiments and comparative examples are listed in Table 1 below.
[0089] Table 1
[0090] Analysis of the data in Table 1 shows that, compared to Comparative Example 1, the filling rate of the sound-absorbing material 40 in the rear acoustic cavity of Example 1 increased by 14.3%, reaching 96.4%, and the F0 value of the loudspeaker was 22 Hz lower than that of Comparative Example 1. Compared to Comparative Example 1 (purely filled with sound-absorbing particles 42), in Example 2, under the same rear acoustic cavity filling rate, selecting a suitable ratio of activated carbon powder 41 to sound-absorbing particles 42 resulted in less filling time, higher filling efficiency, and consistent performance.
[0091] The results above show that the combined use of activated carbon powder 41 and sound-absorbing particles 42 can effectively fill the space of the rear acoustic cavity of the loudspeaker. For the loudspeaker module of this project, the filling rate can reach 96.4%, which can more effectively improve the resonant frequency F0 of the loudspeaker. At the same time, the appropriate combination ratio can reduce the filling time and improve the filling efficiency.
[0092] (ii) Reliability Testing Each speaker module in the above embodiments and comparative examples was connected to a high-power lifespan test, with a voltage of 2.83 V, white noise signal, and powered on for 96 hours. Afterwards, changes in acoustic performance were tested, and the magnetic circuit was disassembled to check for any powder leakage contamination of the magnetic circuit. The test results are detailed in Table 2 below.
[0093] Table 2
[0094] As can be seen from the experimental results in Table 2, the change in F0 of the loudspeaker in all three groups of experiments was within 20 Hz, which is within the acceptable range of 60 Hz, and is therefore considered OK.
[0095] Meanwhile, the sound-generating units 20 of the three loudspeakers were disassembled to observe the powder leakage in the magnetic circuit system. No powder leakage was found in any of the three loudspeakers, indicating that each loudspeaker performed OK in the reliability test.
[0096] In summary, the sound-generating device provided by the present invention, while meeting the requirements for acoustic performance reliability, can increase the filling amount of sound-absorbing material 40 in the rear acoustic cavity and improve filling efficiency.
[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A sound-generating device, characterized in that, The device includes a housing with an internal space, a sound-generating unit disposed within the housing, and a breathable insulating component. The sound-generating unit cooperates with the housing to define a front acoustic cavity and a rear acoustic cavity within the internal space of the housing. The rear acoustic cavity is filled with sound-absorbing material, and the breathable insulating component isolates the sound-absorbing material from the sound-generating unit. The sound-absorbing material includes activated carbon powder and sound-absorbing particles. The sound-absorbing particles are spherical particles formed by bonding multiple molecular sieve powder particles, and the average particle size D50 of the sound-absorbing particles is 150 μm to 1000 μm. The activated carbon powder has a hydrophobic surface structure, the average particle size D50 of the activated carbon powder is 5 μm to 100 μm, and the pore size of the breathable insulating element is smaller than the minimum particle size of the activated carbon powder.
2. The sound-generating device as described in claim 1, characterized in that, The activated carbon powder accounts for 4% to 50% of the total volume of the sound-absorbing material, and the sound-absorbing particles account for 50% to 96% of the total volume of the sound-absorbing material.
3. The sound-generating device as described in claim 1, characterized in that, The ratio of the average particle size D50 of the sound-absorbing particles to the average particle size D50 of the activated carbon powder is greater than 5.
4. The sound-generating device as claimed in claim 1, characterized in that, The sound-absorbing particles contain a through-pore structure with a pore size of 500 nm to 8000 nm.
5. The sound-generating device as claimed in claim 1, characterized in that, The sound-absorbing particles are spherical particles formed by bonding an adhesive with multiple molecular sieve powder particles with an average particle size of 0.1 μm to 30 μm.
6. The sound-generating device as claimed in claim 1, characterized in that, The molecular sieve powder has a crystal structure that includes one of the following: MFI, MTW, FER, MOR, MEL, CHA, and LTL crystal structures. And / or, the silicon-to-aluminum ratio of the molecular sieve powder is greater than 10.
7. The sound-generating device as claimed in claim 1, characterized in that, The hydrophobic structure of the activated carbon powder includes at least one of the following: silane hydrophobic groups, fluorine-containing atom grafted groups, metal oxide hydrophobic layers, graphene layers, and carbon nanotube layers.
8. The sound-generating device as claimed in claim 1, characterized in that, The water absorption rate of the activated carbon powder is <5%.
9. The sound-generating device as claimed in claim 1, characterized in that, The activated carbon powder particles contain a microporous structure with a pore size of 0.3 nm to 1.8 nm; And / or, the specific surface area of the activated carbon powder particles is greater than 1000 m². 2 / g.
10. The sound-generating device as claimed in claim 1, characterized in that, The activated carbon powder particles include one of the following shapes: spherical, near-spherical, ellipsoidal, rod-shaped, cross-shaped, block-shaped, polygonal, and irregular.
11. The sound-generating device as claimed in claim 1, characterized in that, The air permeability of the breathable insulating element is 500 L / m. 2 .s@20mmH2O~6000 L / m 2 .s@20mmH2O.
12. The sound-generating device as claimed in claim 1, characterized in that, The material of the breathable insulating component includes one of the following: polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, stainless steel, aluminum, copper, and natural fibers. Alternatively, the breathable insulating element may be a woven mesh fabric.
13. The sound-generating device as claimed in claim 1, characterized in that, The sound-generating unit includes a shell with an internal cavity, the shell having an air outlet communicating with the internal cavity, and a breathable insulating member connecting the shell and blocking the air outlet; or... The housing includes a first housing and a second housing connected to each other. The first housing and the second housing together form an internal space of the housing. The first housing has a first mounting groove on the side near the second housing, and the second housing has a second mounting groove on the side near the first housing. The breathable isolation component includes a mounting frame and a breathable component disposed in the mounting frame. The opposite sides of the mounting frame are respectively mounted in the first mounting groove and the second mounting groove.
14. An electronic device, characterized in that, The sound-generating device includes any one of claims 1 to 13.