Vibration plate, diaphragm assembly and sound generating device

Abstract

The application discloses a vibrating plate, a vibrating diaphragm assembly and a sound generating device, and relates to the acoustic field. The vibrating plate is applied to the sound generating device. At least a part of the vibrating plate is a composite fiber structure. The composite fiber structure comprises a frame structure formed by three-dimensional mixed weaving of first fibers and second fibers and a resin matrix. The resin matrix is filled in at least a hollow space of the frame structure. The first fibers are carbon fibers. The second fibers comprise at least one of metal fibers and organic fibers. The weight of the first fibers accounts for 10% to 70% of the total weight of the composite fiber structure. The weight of the second fibers accounts for 30% to 60% of the total weight of the composite fiber structure. The compression strength of the composite fiber structure in the thickness direction is greater than or equal to 200 MPa. According to the vibrating plate, the advantages of light weight and high strength can be achieved, and the actual needs of light weight and high strength of electronic equipment can be met.

Description

Technical Field

[0001] This invention relates to the field of acoustics, specifically to a vibrating plate, a diaphragm assembly, and a sound-generating device. Background Technology

[0002] With the trend towards thinner and lighter electronic devices, the requirements for lightweight structures in sound-generating devices are becoming increasingly stringent. Therefore, low-density non-metallic materials such as carbon fiber have gradually replaced metallic materials as the main raw material for the diaphragm plates of sound-generating devices. However, carbon fiber has low radial strength and is prone to fiber splitting. Diaphragms made of carbon fiber exhibit low compressive strength along their thickness direction during high-frequency vibration, making them susceptible to splitting vibrations, which in turn reduces the acoustic performance of the sound-generating device. Summary of the Invention

[0003] The main objective of this invention is to provide a vibrating plate, a diaphragm assembly, and a sound-generating device, which aims to solve the problem that the vibrating plate of existing sound-generating devices cannot simultaneously meet the requirements of lightweight and high strength.

[0004] To achieve the above objectives, the present invention provides a vibrating plate, which is applied to a sound-generating device. At least a portion of the vibrating plate is a composite fiber structure, which includes a frame structure formed by three-dimensional weaving of a first fiber and a second fiber and a resin matrix. The resin matrix at least fills the hollow space of the frame structure.

[0005] Wherein, the first fiber is carbon fiber, the second fiber is at least one of metal fiber and organic fiber, the weight of the first fiber accounts for 10% to 70% of the total weight of the composite fiber structure, the weight of the second fiber accounts for 30% to 60% of the total weight of the composite fiber structure, and the compressive strength of the composite fiber structure in the thickness direction is greater than or equal to 200 MPa.

[0006] Optionally, the diameter of the first fiber is 1 to 20 μm, and the tensile modulus of the first fiber is greater than or equal to 200 GPa.

[0007] Optionally, the diameter of the second fiber is 1 to 100 μm;

[0008] And / or, the breaking elongation of the second fiber is greater than or equal to 2%;

[0009] And / or, the thermal conductivity of the second fiber is greater than or equal to 5 W / m*K.

[0010] Optionally, the metal fiber includes at least one of titanium fiber, aluminum fiber, copper fiber, nickel fiber, lead fiber, silver fiber, gold fiber, iron fiber, and stainless steel fiber.

[0011] Optionally, the organic fiber includes at least one of aramid fiber, polyimide fiber, polyacrylonitrile fiber, polyester fiber, and liquid crystal polymer fiber.

[0012] Optionally, the vibrating plate further includes a metal coating covering the surface of the organic fibers, wherein the raw material of the metal coating includes at least one of nickel, copper, aluminum, silver and gold.

[0013] Optionally, the resin in the resin matrix includes at least one of thermoplastic resin and thermosetting resin;

[0014] The thermoplastic resin includes at least one of polyamide, polycarbonate, polyoxymethylene, polyphenylene sulfide, polyphenylene ether, polysulfone, polyimide, polyethersulfone, polyetherimide, polyetheretherketone, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, and acrylonitrile / butadiene / styrene copolymer.

[0015] The thermosetting resin includes at least one of epoxy resin, phenolic resin, and bismaleimide resin.

[0016] Optionally, the weight of the resin matrix accounts for 20% to 50% of the total weight of the composite fiber structure;

[0017] And / or, the long-term service temperature of the resin matrix is ​​greater than or equal to 150°C.

[0018] Optionally, the density of the composite fiber structure is less than 5 g / cm3;

[0019] And / or, the thermal conductivity of the composite fiber structure in the thickness direction is greater than or equal to 5 W / m*K.

[0020] Optionally, the composite fiber structure is formed by hot pressing the frame structure after pre-impregnation with resin, or by resin transfer molding of the frame structure, or by resin membrane infiltration of the frame structure.

[0021] Optionally, the flexural modulus of the composite fiber structure is greater than or equal to 10 GPa;

[0022] And / or, the modulus density ratio of the composite fiber structure is greater than or equal to 20 GPa·cm3 / g.

[0023] Optionally, all parts of the vibrating plate are composed of the composite fiber structure.

[0024] The present invention also provides a diaphragm assembly, including a diaphragm and a vibrating plate as described above connected to the diaphragm.

[0025] The present invention also provides a sound generating device, the sound generating device comprising the diaphragm assembly as described above.

[0026] This invention provides a vibrating plate, a diaphragm assembly, and a sound-generating device. The vibrating plate is applied to the sound-generating device, and at least a portion of the vibrating plate is a composite fiber structure. The composite fiber structure includes a frame structure formed by three-dimensional interweaving of a first fiber and a second fiber, and a resin matrix. The resin matrix at least fills the hollow spaces within the frame structure. The first fiber is carbon fiber, and the second fiber is at least one of metal fiber and organic fiber. The weight of the first fiber accounts for 10% to 70% of the total weight of the composite fiber structure, and the weight of the second fiber accounts for 30% to 60% of the total weight of the composite fiber structure. The compressive strength of the composite fiber structure in the thickness direction is greater than or equal to 200 MPa. Through three-dimensional interweaving, the highly resilient second fiber is interwoven with the less dense but less radially strong carbon fiber. On the one hand, the introduction of carbon fiber reduces the density of the composite fiber structure, which is beneficial for weight reduction of the vibrating plate. On the other hand, the high toughness of the metal fiber is utilized to compensate for the radial strength of the carbon fiber through three-dimensional interweaving, enabling the compressive strength of the composite fiber structure in the thickness direction to reach over 200 MPa, effectively preventing fiber splitting. Therefore, this invention solves the technical problem that the vibrating plate of existing sound-generating devices cannot simultaneously meet the requirements of lightweight and high strength, and provides a vibrating plate that combines lightweight and high strength, which is beneficial to meeting the actual needs of electronic devices for both lightweight and high strength. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the composite fiber structure in an embodiment of the present invention;

[0029] Figure 2 This is another structural schematic diagram of the composite fiber structure in an embodiment of the present invention;

[0030] Figure 3 This is a comparison graph of the frequency response curves of the embodiments and comparative examples of the present invention.

[0031] Explanation of reference numerals in the accompanying drawings of the embodiments:

[0032] 30 Second fiber

[0033] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] This invention provides a vibrating plate. In one embodiment of the vibrating plate, refer to... Figure 1 The vibrating plate is used in a sound-generating device. At least a part of the vibrating plate is a composite fiber structure. The composite fiber structure includes a frame structure formed by three-dimensional weaving of a first fiber 20 and a second fiber 30 and a resin matrix 10. The resin matrix 10 is at least filled in the hollow space of the frame structure.

[0036] The first fiber 20 is carbon fiber, and the second fiber 30 is at least one of metal fiber and organic fiber. The weight of the first fiber 20 accounts for 10% to 70% of the total weight of the composite fiber structure, and the weight of the second fiber 30 accounts for 30% to 60% of the total weight of the composite fiber structure. The compressive strength of the composite fiber structure in the thickness direction is greater than or equal to 200 MPa.

[0037] In this embodiment, the sound-generating device includes a vibration system and a magnetic circuit system that cooperates with the vibration system. The vibration system includes a diaphragm assembly and a voice coil coupled to one side of the diaphragm assembly. The magnetic circuit system drives the voice coil to vibrate, thereby causing the diaphragm assembly to produce sound. The diaphragm assembly includes a diaphragm and a vibrating plate connected to the diaphragm. Part or all of the vibrating plate is a composite fiber structure. The composite fiber structure includes a frame structure formed by three-dimensional weaving of first and second fibers and a resin matrix. The resin matrix at least fills the hollow spaces of the frame structure and may also cover the frame structure. The resin can be in a liquid state under certain heating conditions. Liquid resin has a certain fluidity and can fill the hollow spaces of the frame structure. After filling with resin, the frame structure can be bonded into a whole by curing or cooling the resin, thereby transferring and distributing the stress borne to each fiber that makes up the frame structure, so that the first fiber, the second fiber, and the resin matrix in the vibrating plate can jointly resist deformation and load.

[0038] Reference Figure 1 and Figure 2 , Figure 1 and Figure 2The curves and dots in the diagram represent fibers, with dots indicating fibers distributed perpendicular to the paper surface. The three-dimensional hybrid weaving forms a mesh-like framework structure. The first fiber 20 and the second fiber 30 are interwoven, penetrating at least the major axis, minor axis, and thickness of the dome, forming a unified whole. The distribution direction and weaving method of the first and second fibers can be determined based on actual information, and this embodiment does not impose any restrictions on this. This avoids the delamination problem that may exist in multi-layer structures, and when the composite fiber structure is subjected to stress, the stress can be evenly transferred and distributed to each fiber and in each direction, thereby improving the mechanical properties of the vibrating plate in the thickness direction. This increases the compressive strength of the composite fiber structure in the thickness direction to over 200 MPa, overcoming the defects of traditional carbon fiber composites such as easy delamination and low strength in the thickness and radial directions. The intertwining of fibers makes the composite fiber structure less prone to deformation when subjected to bending stress, effectively improving the flexural modulus.

[0039] Optionally, the resin in the resin matrix includes at least one of thermoplastic resin and thermosetting resin;

[0040] Thermoplastic resins include at least one of polyamide, polycarbonate, polyoxymethylene, polyphenylene sulfide, polyphenylene ether, polysulfone, polyimide, polyethersulfone, polyetherimide, polyetheretherketone, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, and acrylonitrile / butadiene / styrene copolymer;

[0041] Thermosetting resins include at least one of epoxy resins, phenolic resins, and bismaleimide resins.

[0042] In this embodiment, epoxy resin refers to a resin whose molecular structure contains two or more epoxy groups. The active epoxy groups can react with various curing agents to form a three-dimensional network structure. The cured epoxy resin is infusible, insoluble, has high hardness, good heat resistance, good flexibility, and good dimensional stability.

[0043] Optionally, the weight of the resin matrix accounts for 20% to 50% of the total weight of the composite fiber structure;

[0044] And / or, the long-term service temperature of the resin matrix is ​​greater than or equal to 150°C.

[0045] In this embodiment, a higher resin content in the composite fiber structure results in better toughness but lower strength. Conversely, a low resin content leads to poor resin wetting of the fibers, poor matrix continuity, discontinuous load transfer, and lower mechanical properties of the composite fiber structure. Therefore, the weight of the resin matrix is ​​determined to be 20%–50% of the total weight of the composite fiber shell, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc. The long-term operating temperature of the resin is ≥150℃ to improve the strength of the components inside the shell under high power or high temperature conditions and to prevent high-temperature deformation of the shell.

[0046] The first fiber is carbon fiber, which has the advantages of high modulus, high strength and low density, which can effectively improve the high frequency performance of loudspeakers. It has high tensile strength along the fiber radial direction and good thermal conductivity. However, carbon fiber is anisotropic, has poor toughness, low radial compressive strength and is prone to fiber splitting. When a diaphragm made of multi-layer carbon fiber material is used, the compressive strength along the thickness direction is low during high frequency vibration and it is easy to delaminate and cause split vibration, which leads to a reduction in the acoustic performance of the sound-generating device.

[0047] The second fiber includes at least one of metal fibers and organic fibers. The metal fibers include at least one of titanium fibers, aluminum fibers, copper fibers, nickel fibers, lead fibers, silver fibers, gold fibers, iron fibers, and stainless steel fibers. The non-metal fibers include at least one of aramid fibers, polyimide fibers, polyacrylonitrile fibers, polyester fibers, and liquid crystal polymer fibers. Metal fibers and organic fibers have good toughness and high strength. Therefore, the first and second fibers can be three-dimensionally blended. The weight of the first fiber accounts for 10% to 70% of the total weight of the composite fiber structure, for example, 10%, 30%, 50%, 70%, etc., while the weight of the second fiber accounts for 30% to 60% of the total weight of the composite fiber structure, for example, 30%, 40%, 50%, 60%, etc. The first fiber enables the composite fiber structure to meet the requirements of high modulus and low density. Simultaneously, the second fiber and the three-dimensional blending supplement and improve the strength in the thickness direction of the composite fiber structure, thereby obtaining a composite fiber structure that combines high modulus, low density, and high compressive strength along the thickness direction. The density of the obtained composite fiber structure is less than 5 g / cm³. 3 And / or, the flexural modulus is greater than or equal to 10 GPa, and / or, the modulus-to-density ratio is greater than or equal to 20 GPa·cm. 3 / g.

[0048] Metal fibers are fibers made from metallic materials such as metals, alloys, or metal compounds. Methods for manufacturing metal fibers include melt drawing, monofilament drawing, and bundle drawing. Bundle drawing involves wrapping tens to tens of thousands of metal fibers in a cylindrical tube and drawing them, thus simultaneously reducing the diameter of multiple metal fibers within the tube. After drawing, the covering material is removed, separating the metal fibers. Metal wires produced by bundle drawing have small and uniform diameters, with filament diameters reduced to 1 μm. However, on the one hand, if the metal fiber diameter is too large, the thickness of a single layer of metal fibers will be greater, leading to an increase in the thickness and weight of the shell. On the other hand, metal fibers contain inclusions such as carbides. During the metal fiber diameter reduction process, these inclusions are brought to the surface or subsurface of the metal fiber. Inclusions have a relatively small impact on large-diameter metal fibers, but when the metal fiber diameter is too small, inclusions not only cause uneven distribution of the metal fiber composition but may also cause damage or even breakage of the metal fiber at the inclusion sites, affecting the fiber's mechanical properties. Therefore, the diameter of the metal fiber is determined to be 1 to 100 μm, such as 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc. In one feasible method, the diameter of the metal fiber is 5 to 20 μm, such as 5 μm, 7 μm, 10 μm, 13 μm, 15 μm, 18 μm, 20 μm, etc. The shell made of metal fiber with a diameter in the range of 5 to 20 μm has a moderate thickness and weight, which meets the requirements of thin and light shells, and is not easy to break, with good mechanical properties.

[0049] Optionally, the vibrating plate also includes a metal coating covering the surface of the organic fiber layer, wherein the raw material of the metal coating includes at least one of nickel, copper, aluminum, silver and gold.

[0050] In this embodiment, when the second fiber is an organic fiber, the thermal conductivity of the organic fiber can be increased by adding a metal coating to the surface of the organic fiber. The raw materials of the metal coating include at least one of nickel, copper, aluminum, silver and gold.

[0051] As the amplitude and voltage of the sound-generating device increase, the work done by the voice coil increases significantly, leading to a substantial increase in heat generation. The dome temperature can reach over 120°C. The carbon fiber diaphragm has a low thermal conductivity in the thickness direction, resulting in poor heat dissipation. This prevents the heat generated by the sound-generating device from dissipating effectively, causing an overall increase in the temperature of the electronic equipment containing the sound-generating device. While carbon fiber has good thermal conductivity in the radial direction, its axial thermal conductivity is poor. Therefore, multi-layered composite carbon fiber structures have poor thermal conductivity in the thickness direction. To address this, a three-dimensional hybrid weaving method can be used to create a continuous thermal path along the thickness of the diaphragm, transferring heat generated inside the speaker along the fibers to the outside of the dome and radiating it into the air. This increases the thermal conductivity of the composite fiber structure to over 5 W / m*K.

[0052] Optionally, the diameter of the first fiber is 1 to 20 μm, and the tensile modulus of the first fiber is greater than or equal to 200 GPa.

[0053] In this embodiment, if the diameter of the first fiber is too large, the volume of the composite fiber structure will be large; if the diameter of the first fiber is too small, the processing will be difficult and it will be prone to breakage during processing and use. Therefore, the diameter of the first fiber is determined to be 1-20 μm, such as 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, etc. The higher the modulus of the first fiber, the higher the modulus of the vibrating plate, and the less likely it is to undergo segmentation vibration during high-frequency vibration. Therefore, a first fiber with a tensile modulus greater than or equal to 200 GPa is selected. In one feasible embodiment, a first fiber with a tensile modulus greater than or equal to 300 GPa can be selected.

[0054] Optionally, the diameter of the second fiber is 1–100 μm;

[0055] And / or, the breaking elongation of the second fiber is greater than or equal to 2%;

[0056] And / or, the thermal conductivity of the second fiber is greater than or equal to 5 W / m*K.

[0057] In this embodiment, the first fiber is carbon fiber. Carbon fiber has poor toughness, low axial strength and low axial thermal conductivity. Therefore, it can be compensated by selecting a second fiber with better toughness and higher thermal conductivity. Thus, a second fiber with a breaking elongation greater than or equal to 2% and / or a thermal conductivity greater than or equal to 5 W / m*K can be selected.

[0058] If the diameter of the second fiber is too large, the volume of the composite fiber structure will be too large; if the diameter of the second fiber is too small, the processing will be difficult and it will be easy to break during processing and use. Therefore, the diameter of the second fiber is determined to be 1 to 100 μm, such as 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc.

[0059] Optionally, the composite fiber structure is formed by hot pressing of a frame structure after pre-impregnation with resin, or by resin transfer molding of a frame structure, or by resin membrane infiltration of a frame structure.

[0060] In this embodiment, the first fiber and the second fiber can be three-dimensionally braided to form a frame structure. The frame structure can then be pre-impregnated with resin to obtain a prepreg, which can be hot-pressed. Alternatively, the frame structure can be formed using a resin transfer molding process, i.e., the frame structure is placed in a closed mold cavity, resin is injected into the cavity under pressure to impregnate the frame structure, it is cured, and then demolded. Alternatively, the frame structure can be formed using a resin membrane infiltration process, i.e., a pre-catalyzed resin membrane or resin block is placed in the mold cavity, then the frame structure is placed on top, the mold cavity is sealed with a vacuum bag, a vacuum is drawn, and the mold is heated to melt the resin membrane or resin block inside the cavity, allowing it to infiltrate into the frame structure under vacuum, cure, and then demold.

[0061] In this embodiment, a vibrating plate is used in a sound-generating device. At least a portion of the vibrating plate is a composite fiber structure, comprising a frame structure formed by three-dimensional interweaving of a first fiber and a second fiber, and a resin matrix. The resin matrix at least fills the hollow spaces within the frame structure. The first fiber is carbon fiber, and the second fiber is at least one of metal fiber and organic fiber. The weight of the first fiber accounts for 10% to 70% of the total weight of the composite fiber structure, and the weight of the second fiber accounts for 30% to 60% of the total weight of the composite fiber structure. The compressive strength of the composite fiber structure in the thickness direction is greater than or equal to 200 MPa. Through three-dimensional interweaving, the highly resilient second fiber is interwoven with the less dense but less radially strong carbon fiber. On the one hand, the introduction of carbon fiber reduces the density of the composite fiber structure, which is beneficial for weight reduction of the vibrating plate. On the other hand, the high toughness of the metal fiber is utilized to compensate for the radial strength of the carbon fiber through three-dimensional interweaving, enabling the compressive strength of the composite fiber structure in the thickness direction to reach over 200 MPa, effectively preventing fiber splitting. Therefore, this invention solves the technical problem that the vibrating plate of existing sound-generating devices cannot simultaneously meet the requirements of lightweight and high strength, and provides a vibrating plate that combines lightweight and high strength, which is beneficial to meeting the actual needs of electronic devices for both lightweight and high strength.

[0062] Furthermore, the present invention also discloses a diaphragm assembly, which includes a diaphragm and a vibrating plate as described above connected to the diaphragm.

[0063] The diaphragm assembly provided by this invention solves the technical problem that the vibrating plates of existing sound-generating devices cannot simultaneously meet the requirements of lightweight and high strength. Compared with the prior art, the beneficial effects of the diaphragm assembly provided by the embodiments of this invention are the same as the beneficial effects of the vibrating plates in the above embodiments, and will not be repeated here.

[0064] Furthermore, the present invention also discloses a sound-generating device, which includes the diaphragm assembly as described above.

[0065] In this embodiment, the sound-generating device includes a vibration system and a magnetic circuit system that cooperates with the vibration system. The vibration system includes the diaphragm assembly as described above, and also includes a voice coil coupled to one side of the diaphragm assembly. The magnetic circuit system drives the voice coil to vibrate so as to drive the diaphragm assembly to generate sound.

[0066] The sound-generating device provided by this invention solves the technical problem that the vibrating plate of existing sound-generating devices cannot simultaneously meet the requirements of lightweight and high strength. Compared with the prior art, the beneficial effects of the sound-generating device provided by the embodiments of this invention are the same as the beneficial effects of the vibrating plate in the above embodiments, and will not be repeated here.

[0067] The housing of the present invention will now be described in detail with reference to specific embodiments and comparative examples. It is to be understood that the following description is merely exemplary and not intended to limit the specific scope of the invention.

[0068] Example

[0069] The total thickness of the vibrating plate is 300μm. The first fiber is carbon fiber, the second fiber is aluminum fiber, and the resin matrix is ​​epoxy resin matrix. The aluminum fiber accounts for 40% of the mass, the carbon fiber is high-modulus carbon fiber, accounting for 30% of the mass, and the epoxy resin matrix accounts for 30%. The aluminum fiber and carbon fiber are three-dimensionally woven, pre-impregnated with resin, and then heated and pressurized to form the vibrating plate, which has a flat plate structure.

[0070] Comparative Example

[0071] The total thickness of the vibrating plate is 300μm. It is formed by two-dimensional weaving of carbon fiber and filled with resin with a resin content of 30%. The vibrating plate has a flat plate structure.

[0072] The comparative and example diaphragms were assembled with polyester elastomer diaphragms using double-sided adhesive to form diaphragm assemblies, which were then assembled into loudspeakers. Their acoustic performance and reliability were tested. The test results are shown in Table 1. The diaphragm assemblies corresponding to the examples and comparative examples were then assembled into sound-generating devices. Frequency response curve tests were performed on the sound-generating devices corresponding to the examples and the comparative examples. The test results are shown in Table 1. Figure 3 As shown.

[0073] Table 1

[0074]

[0075] Therefore, it can be seen that, compared with the comparative example, the bending modulus of the embodiment is significantly better than that of the comparative example. During product manufacturing and reliability testing, the diaphragm is less prone to breakage failure, and the speaker's high-frequency cutoff frequency is higher. The embodiment has greater bending force and better toughness, resulting in a smoother high-frequency curve and better high-frequency sound reproduction during speaker high-frequency vibration. After 600 seconds of high-power operation, the voice coil temperature of the embodiment rose to 115°C, while the voice coil temperature of the comparative example rose to 120°C. The embodiment has a higher thermal conductivity and better thermal performance; the heat generated during speaker operation is conducted and radiated into the outside air through the diaphragm.

[0076] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A vibrating plate, characterized in that, The vibrating plate is used in a sound-generating device. At least a portion of the vibrating plate is a composite fiber structure. The composite fiber structure includes a frame structure formed by three-dimensional weaving of a first fiber and a second fiber, and a resin matrix. The resin matrix fills at least the hollow space of the frame structure. The first fiber is carbon fiber, and the second fiber includes at least one of metal fiber and organic fiber. The weight of the first fiber accounts for 10% to 70% of the total weight of the composite fiber structure, and the weight of the second fiber accounts for 30% to 60% of the total weight of the composite fiber structure. The compressive strength of the composite fiber structure in the thickness direction is greater than or equal to 200 MPa. The frame structure is a three-dimensional mesh, in which the first fiber and the second fiber are interwoven and penetrate the length, width, and thickness directions of the vibrating plate. The thermal conductivity of the second fiber is greater than or equal to 5 W / m. K.

2. The vibrating plate as described in claim 1, characterized in that, The diameter of the first fiber is 1~20μm, and the tensile modulus of the first fiber is greater than or equal to 200GPa.

3. The vibrating plate as described in claim 1, characterized in that, The diameter of the second fiber is 1~100μm; And / or, the breaking elongation of the second fiber is greater than or equal to 2%.

4. The vibrating plate as described in claim 1, characterized in that, The metal fibers include at least one of titanium fiber, aluminum fiber, copper fiber, nickel fiber, lead fiber, silver fiber, gold fiber, iron fiber, and stainless steel fiber.

5. The vibrating plate as described in claim 1, characterized in that, The organic fibers include at least one of aramid fibers, polyimide fibers, polyacrylonitrile fibers, polyester fibers, and liquid crystal polymer fibers.

6. The vibrating plate as described in claim 5, characterized in that, The vibrating plate also includes a metal coating covering the surface of the organic fibers, wherein the raw material of the metal coating includes at least one of nickel, copper, aluminum, silver and gold.

7. The vibrating plate as described in claim 1, characterized in that, The resin in the resin matrix includes at least one of thermoplastic resin and thermosetting resin; The thermoplastic resin includes at least one of polyamide, polycarbonate, polyoxymethylene, polyphenylene sulfide, polyphenylene ether, polysulfone, polyimide, polyethersulfone, polyetherimide, polyetheretherketone, polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polybutylene terephthalate, and acrylonitrile / butadiene / styrene copolymer. The thermosetting resin includes at least one of epoxy resin, phenolic resin, and bismaleimide resin.

8. The vibrating plate as described in claim 7, characterized in that, The weight of the resin matrix accounts for 20% to 50% of the total weight of the composite fiber structure; And / or, the long-term service temperature of the resin matrix is ​​greater than or equal to 150°C.

9. The vibrating plate as described in claim 1, characterized in that, The density of the composite fiber structure is less than 5 g / cm³. 3 ; And / or, the thermal conductivity of the composite fiber structure in the thickness direction is greater than or equal to 5 W / m. K.

10. The vibrating plate as described in claim 1, characterized in that, The composite fiber structure is formed by hot pressing the frame structure after pre-impregnation with resin, or by resin transfer molding of the frame structure, or by resin membrane infiltration of the frame structure.

11. The vibrating plate as described in claim 1, characterized in that, The flexural modulus of the composite fiber structure is greater than or equal to 10 GPa. And / or, the modulus-density ratio of the composite fiber structure is greater than or equal to 20 GPa•cm. 3 / g.

12. The vibrating plate as described in any one of claims 1-11, characterized in that, All parts of the vibrating plate are composed of the composite fiber structure.

13. A diaphragm assembly, characterized in that, It includes a diaphragm and a vibrating plate connected to the diaphragm as described in any one of claims 1-12.

14. A sound-generating device, characterized in that, The sound-generating device includes the diaphragm assembly as described in claim 13.

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