Vibrating plate for sound production device, vibrating diaphragm assembly and sound production device

Abstract

The invention belongs to the technical field of electroacoustics, and particularly relates to a vibrating plate for a sound production device, a vibrating diaphragm assembly and the sound production device, and main body part preparation raw materials of the vibrating plate for the sound production device comprise an aluminum alloy material and silicon carbide powder mixed in the aluminum alloy material, the volume fraction of the silicon carbide powder in the preparation raw materials of the main body part is 1-50%, the type of the silicon carbide powder is 6H type alpha-SiC, and the particle size D90 of the silicon carbide powder is 0.1-20 [mu] m. The vibration plate with high specific modulus and high yield strength is obtained by controlling the type, the particle size D90, the content and the like of the silicon carbide powder, and then the high-frequency cut-off frequency of the sound production device is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electroacoustics, and particularly relates to a diaphragm, a diaphragm assembly and a sound generating device for a sound generating device. Background Art

[0002] With the increasing requirements for the high-frequency performance of loudspeakers in the industry, the loudspeaker diaphragm needs to have a high elastic modulus. Some loudspeakers use diaphragms made of aluminum alloy or titanium alloy. However, titanium alloy usually has a close-packed hexagonal structure with a dense atomic packing, making it difficult to undergo plastic deformation and difficult to be processed into the required shape. Aluminum alloy can improve mechanical indexes such as yield strength through alloying, but the elastic moduli of different series of aluminum alloys are similar, all about 70 GPa. Therefore, when the performance of existing aluminum alloy materials cannot meet the requirements, there is no suitable material to replace them.

[0003] Therefore, the diaphragms for existing sound generating devices still need to be improved. Summary of the Invention

[0004] The purpose of the present invention is to provide a diaphragm, a diaphragm assembly and a sound generating device for a sound generating device. The diaphragm has a high specific modulus and a high yield strength, thereby improving the high-frequency cut-off frequency of the sound generating device.

[0005] The first aspect of the present invention provides a diaphragm for a sound generating device. The raw materials for preparing the main body of the diaphragm include an aluminum alloy material and silicon carbide powder mixed in the aluminum alloy material. The volume fraction of the silicon carbide powder in the raw materials for preparing the main body is 1% - 50%. The type of the silicon carbide powder is 6H type α-SiC, and the particle size D90 of the silicon carbide powder is between 0.1 μm and 20 μm.

[0006] In some embodiments of the present invention, the shape of the silicon carbide powder includes at least one of spherical, flaky, and irregular polyhedral shapes.

[0007] In some embodiments of the present invention, the silicon carbide powder is obtained through modification treatment, and the modification treatment includes at least one of pre-oxidation treatment, metal plating treatment, acid treatment, alkali treatment, and silane coupling agent treatment.

[0008] In some embodiments of the present invention, the aluminum alloy material includes one of 1xxx, 3xxx, 5xxx, 6xxx, 7xxx, and 8xxx series aluminum alloys.

[0009] In some embodiments of the present invention, an additive element is further provided in the aluminum alloy material. The additive element is at least one of Mg, Si, Ti, Cu, Zr, and Y, and the addition amount of the additive element accounts for 0.1 wt% - 10 wt% of the aluminum alloy material.

[0010] In some embodiments of the present invention, the specific modulus of the vibration plate is between 25 GPa / (g / cm 3 )~50GPa / (g / cm 3 ) between; and / or, the density of the vibration plate is between 2.5g / cm 3 ~3g / cm 3 between.

[0011] In some embodiments of the present invention, the thickness of the vibration plate is between 5 μm and 500 μm; and / or the yield strength of the vibration plate is between 50 MPa and 500 MPa.

[0012] In some embodiments of the present invention, the vibration plate is formed by stamping an aluminum foil material, wherein the stamping is cold stamping or heated warm stamping, and the temperature of the heated warm stamping is between 50°C and 300°C; the aluminum foil material is made by mixing an aluminum alloy material with the silicon carbide powder using powder metallurgy and rolling.

[0013] In some embodiments of the present invention, a reinforcing rib is formed on at least one side surface of the main body of the vibration plate, and the reinforcing rib is integrally stamped with the main body.

[0014] The second aspect of the present invention further provides a diaphragm assembly, which includes a folding ring and a vibration plate arranged at the center of the folding ring. The vibration plate is the vibration plate described in the first aspect. The folding ring and the vibration plate are integrally injection molded or bonded together by an adhesive.

[0015] The third aspect of the present invention further provides a sound-generating device, which includes a vibration system and a magnetic circuit system coordinated with the vibration system, wherein the vibration system includes the diaphragm assembly described in the second aspect and a voice coil coupled to one side of the diaphragm assembly.

[0016] The vibration plate in the present invention is prepared from raw materials for the main part of the vibration plate, including an aluminum alloy material and silicon carbide powder mixed in the aluminum alloy material. By controlling the type of the silicon carbide powder to be 6H-type α-SiC and the particle size D90 to be between 0.1μm and 20μm, a vibration plate with high specific modulus and high yield strength is obtained, thereby increasing the high-frequency cutoff frequency of the sound-generating device and improving the sound effect of the sound-generating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Schematic diagram of silicon carbide powder in an embodiment of the present invention; wherein, A represents silicon carbide powder.

[0019] Figure 2 Cross-sectional view of the diaphragm assembly in an embodiment of the present invention.

[0020] Figure 3 Top view of the vibrating plate with reinforcing ribs in an embodiment of the present invention.

[0021] Figure 4 is Figure 3 Cross-sectional view in the A-A direction in

[0022] Figure 5 Cross-sectional view of the sound generating device in an embodiment of the present invention.

[0023] Figure 6 Tensile curve of the vibrating plate in the embodiment of the present invention and the comparative example.

[0024] Figure 7 FR curve of the loudspeaker formed by the vibrating plate in the embodiment of the present invention and the comparative example.

[0025] Explanation of reference numerals:

[0026] 100, sound generating device;

[0027] 10, housing; 20, diaphragm assembly; 21, vibrating plate; 22, surround; 23, reinforcing rib; 30, voice coil; 40, magnetic circuit system. Detailed implementation manners

[0028] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be fully conveyed to those skilled in the art.

[0029] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of the stated features, steps, operations, elements, and / or components, but do not preclude 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 to be construed as necessarily requiring them to be performed in the particular order described or illustrated, unless the order of performance is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0030] In the description of the embodiments of the present invention, the technical terms "first", "second", etc. are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order, or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "a plurality of" is more than two, unless otherwise specifically defined.

[0031] Reference to "an embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present invention. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive of other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0032] In the description of the embodiments of the present invention, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0033] In the description of the embodiments of the present invention, the term "a plurality of" refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of pieces" refers to more than two pieces (including two pieces).

[0034] In the description of the embodiments of the present invention, unless otherwise clearly defined and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0035] The first aspect of the present invention provides a diaphragm for a sound generating device. In combination Figure 1 Introduction, the raw materials for preparing the main body of the diaphragm include an aluminum alloy material and silicon carbide powder mixed in the aluminum alloy material. The volume fraction of the silicon carbide powder in the raw materials for preparing the main body is 1% to 50%, the type of the silicon carbide powder is 6H type α-SiC, and the particle size D90 of the silicon carbide powder is between 0.1 μm and 20 μm.

[0036] In the embodiments of the present invention, silicon carbide has a high melting point, high hardness, and high elastic modulus, and can form a good interfacial bond with the aluminum alloy matrix. On the other hand, silicon carbide is easy to prepare and has a low cost. Specifically, 6H type α-silicon carbide can be selected. The diaphragm in the present invention combines the advantages of aluminum alloy and silicon carbide and has excellent mechanical and physical properties such as high strength, high modulus, and low density. The addition of silicon carbide powder, as a crystallization core, is beneficial to the nucleation of the aluminum alloy matrix. Therefore, the aluminum alloy grains are smaller, and the aluminum alloy material has higher strength and modulus. On the other hand, the thermal expansion coefficients of silicon carbide and the aluminum alloy matrix are different, resulting in an increase in the dislocation density during processing, dislocation entanglement, and difficult deformation. Therefore, it has higher strength and elastic modulus.

[0037] The particle size D90 of the silicon carbide powder provided by the present invention is the powder diameter when the cumulative volume distribution is 90%, that is, the particle diameters of 90% are smaller than this value. In the embodiments of the present invention, the particle size D90 of the silicon carbide powder is between 0.1 μm and 20 μm. As a nucleation core, the larger the size of silicon carbide, the larger the grain size, and the yield strength of the strengthened aluminum alloy decreases with the increase in the size of the silicon carbide powder. Therefore, the diameter should not be too large. If the diameter of the silicon carbide powder is too small, the fine particles are prone to agglomeration, and the strengthening effect is poor. On the other hand, dislocations can bypass the powder and move, so there is no obvious improvement in the strength of the material.

[0038] The D90 particle size of the silicon carbide powder provided by the present invention can be a value within the range formed by any two values within the above range. For example, it can be 1 μm to 10 μm, or it can be 10 μm to 20 μm, and so on. Exemplarily, the D90 particle size of the silicon carbide powder can also be one of 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm or any value that satisfies the above range.

[0039] In the embodiments of the present invention, the larger the volume fraction of the silicon carbide powder, the greater the dislocation density and the higher the strength of the material. However, the larger the volume fraction of the silicon carbide powder, the greater the material density. Therefore, the volume fraction of the silicon carbide powder in the raw materials for preparing the main body is 1% to 50%, thereby enabling the vibrating plate to have a relatively high elastic modulus and a relatively low density.

[0040] The volume fraction of the silicon carbide powder provided by the present invention can be a value within the range formed by any two values within the above range. For example, it can be 1% to 5%, or it can be 5% to 30%, or it can be 30% to 50%, and so on. Exemplarily, the volume fraction of the silicon carbide powder can also be one of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50% or any value that satisfies the above range.

[0041] In the embodiments of the present invention, the shape of the silicon carbide powder includes at least one of spherical, flaky, and irregular polyhedral shapes. For example, the shape of the silicon carbide can be spherical, flaky, or irregular polyhedral.

[0042] In some embodiments of the present invention, spherical silicon carbide powder is used. Spherical shapes are easy to disperse in the aluminum alloy matrix, improving the material uniformity. During deformation processes such as tension, stress concentration is not easily generated, and the stress distribution is uniform, thereby avoiding the generation of cracks.

[0043] The mechanical properties of the composite material are affected by the wettability between the reinforcing particles and the aluminum alloy matrix and the interfacial bonding strength. If the interfacial bonding strength is too small, the strengthening effect is limited and the performance improvement is not obvious. In the embodiments of the present invention, in order to further improve the bonding strength and uniformity between the silicon carbide powder and the aluminum alloy material, the silicon carbide powder is subjected to at least one modification treatment among pre-oxidation treatment, metal coating treatment, acid treatment, alkali treatment, and silane coupling agent treatment. The pre-oxidation treatment refers to high-temperature baking of the silicon carbide powder to form a SiO2 layer on its surface. SiO2 has good wettability when contacting the aluminum alloy matrix, and at the same time, it can avoid direct contact between the silicon carbide and the aluminum alloy matrix to generate AL4C3. AL4C3 is brittle, easy to absorb water and hydrolyze. The metal coating treatment refers to forming a metal coating on the surface of the silicon carbide powder. The metal coating has good wettability with the aluminum alloy matrix, which can improve the wettability between the silicon carbide powder and the aluminum alloy matrix, thereby enhancing the interfacial bonding force between the silicon carbide and the matrix. On the other hand, it is beneficial to the uniform distribution of the silicon carbide powder. Acid treatment or alkali treatment can clean the pollutants on the surface of the silicon carbide powder, improve the wettability between the silicon carbide powder and the aluminum alloy matrix, and increase the bonding strength and uniformity. The silane coupling agent treatment is to introduce active groups on the surface of the silicon carbide powder to improve the bonding strength and uniformity between the silicon carbide powder and the aluminum alloy matrix. In the embodiments of the present invention, the aluminum alloy material includes one of 1-series, 3-series, 5-series, 6-series, 7-series, and 8-series aluminum alloys, which are easy to be plastically processed into the required thickness and shape of the vibrating plate.

[0044] In the embodiments of the present invention, in order to further improve the wettability between the aluminum alloy material or the so-called aluminum alloy matrix and the silicon carbide powder, the aluminum alloy material also contains additive elements, and the additive elements can be at least one of elements such as Mg, Si, Ti, Cu, Zr, Y, etc.

[0045] Based on the mass of the aluminum alloy material, the addition amount of the additive elements provided in the embodiments of the present invention accounts for 0.1 wt% - 10 wt% of the aluminum alloy material.

[0046] Exemplarily, the added mass percentage of the Mg element can be a value within any interval composed of any two values within the above range. For example, it can be 0.1 wt% - 5 wt%, or 5 wt% - 10 wt%, and so on. The added mass percentage of the Mg element can also be one of 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt% or any value that satisfies the above range value.

[0047] Exemplarily, the added mass percentage of Si element can be a value within the range formed by any two values within the above range. For example, it can be 0.1wt% - 5wt%, or 5wt% - 10wt%, and so on. The added mass percentage of Si element can also be one of 0.1wt%, 0.2wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt% or any value that satisfies the above range.

[0048] Exemplarily, the added mass percentage of Ti element can be a value within the range formed by any two values within the above range. For example, it can be 0.1wt% - 5wt%, or 5wt% - 10wt%, and so on. The added mass percentage of Ti element can also be one of 0.1wt%, 0.2wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt% or any value that satisfies the above range.

[0049] Exemplarily, the added mass percentage of Cu element can be a value within the range formed by any two values within the above range. For example, it can be 0.1wt% - 5wt%, or 5wt% - 10wt%, and so on. The added mass percentage of Cu element can also be one of 0.1wt%, 0.2wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt% or any value that satisfies the above range.

[0050] Exemplarily, the added mass percentage of Zr element can be a value within the range formed by any two values within the above range. For example, it can be 0.1wt% - 5wt%, or 5wt% - 10wt%, and so on. The added mass percentage of Zr element can also be one of 0.1wt%, 0.2wt%, 0.5wt%, 0.6wt%, 0.8wt%, 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt% or any value that satisfies the above range.

[0051] Exemplarily, the added mass percentage of the Y element can be any value within the range formed by any two values within the above range. For example, it can be 0.1 wt% to 5 wt%, or 5 wt% to 10 wt%, and so on. The added mass percentage of the Y element can also be one of 0.1 wt%, 0.2 wt%, 0.5 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt% or any value that satisfies the above range values.

[0052] The specific modulus of the diaphragm, which is the ratio of the elastic modulus to the density, is directly proportional to the high-frequency frequency response of the speaker. The higher the specific modulus, the higher the cut-off frequency. Therefore, the specific modulus of the diaphragm needs to satisfy ≥ 25 GPa / (g / cm 3 ). The higher the specific modulus, the higher the required elastic modulus, and the larger the volume fraction of the added silicon carbide powder. The increase in the volume fraction of the silicon carbide powder will cause an increase in density. Therefore, considering the actual performance of the material, the specific modulus of the diaphragm needs to satisfy ≤ 50 GPa / (g / cm 3 ).

[0053] In the embodiment of the present invention, the specific modulus of the diaphragm is between 25 GPa / (g / cm 3 ) and 50 GPa / (g / cm 3 ). Exemplarily, the specific modulus of the diaphragm can be 25 GPa / (g / cm 3 ), 26 GPa / (g / cm 3 ), 27 GPa / (g / cm 3 ), 28 GPa / (g / cm 3 ), 29 GPa / (g / cm 3 ), 30 GPa / (g / cm 3 ), 31 GPa / (g / cm 3 ), 32 GPa / (g / cm 3 ), 33 GPa / (g / cm 3 ), 34 GPa / (g / cm 3 ), 35 GPa / (g / cm 3 ), 36 GPa / (g / cm 3 ), 37 GPa / (g / cm 3 ), 38 GPa / (g / cm 3 ), 39 GPa / (g / cm 3 ), 40 GPa / (g / cm 3 ), 41 GPa / (g / cm 3 ), 42 GPa / (g / cm 3)、43 GPa / (g / cm 3 )、44 GPa / (g / cm 3 )、45 GPa / (g / cm 3 )、46 GPa / (g / cm 3 )、47 GPa / (g / cm 3 )、48 GPa / (g / cm 3 )、49 GPa / (g / cm 3 )、50 GPa / (g / cm 3 ) one of those within the above range values or any value satisfying the above range values.

[0054] The weight of the vibration system affects the mid - frequency sensitivity of the speaker. The greater the weight, the lower the sensitivity. When the weight of the voice coil is fixed, the weight of the diaphragm accounts for the majority. The greater the density of the diaphragm, the greater the weight under the same thickness and size. Therefore, the density of the diaphragm cannot be too large. The density of pure aluminum alloy is 2.7 g / cm 3 , if the density needs to be reduced, light metals such as Mg and Li need to be added. The amount of metals that can be added to the aluminum alloy is limited. On the other hand, excessive metals will reduce the mechanical properties such as the strength of the aluminum alloy. Therefore, considering comprehensively in the embodiments of the present invention, the density of the diaphragm is between 2.5 g / cm 3 and 3 g / cm 3 . Exemplarily, the density of the diaphragm can be 2.5 g / cm 3 , 2.6 g / cm 3 , 2.7 g / cm 3 , 2.8 g / cm 3 , 2.9 g / cm 3 , 3 g / cm 3 one of those within the above range values or any value satisfying the above range values.

[0055] When the size of the speaker is fixed, the space of the front and rear cavities of the speaker is fixed within a certain range. When the thickness of the diaphragm is too large, the maximum amplitude that the speaker can reach during vibration becomes smaller and the loudness becomes lower. Therefore, the thickness of the diaphragm should not be too large. When the thickness of the diaphragm is too small, the rigidity of the diaphragm is poor, and it is prone to deformation during vibration, generating splitting vibration, which affects the high - frequency response of the speaker. In the embodiments of the present invention, the thickness of the diaphragm is between 5 μm and 500 μm.

[0056] The thickness of the vibrating plate provided by the present invention can be any value within the range formed by any two values within the above range. For example, it can be 5 μm to 50 μm, or 50 μm to 200 μm, or 200 μm to 500 μm, and so on. Exemplarily, the thickness of the vibrating plate can also be one of 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm or any value satisfying the above range.

[0057] In an embodiment of the present invention, the yield strength of the vibrating plate is between 50 MPa and 500 MPa. The yield strength is the ability of a material to resist microplastic deformation. When the material is subjected to a stress greater than the yield strength, the part undergoes permanent deformation. The higher the yield strength, the stronger the ability of the material to resist deformation. Therefore, the yield strength of the vibrating plate needs to meet ≥50 MPa. However, the higher the yield strength, the more difficult it is to perform plastic deformation. If the yield strength is too high, it is difficult to process the material into the required thickness and shape of the vibrating plate.

[0058] The yield strength of the vibrating plate provided by the present invention can be any value within the range formed by any two values within the above range. For example, it can be 50 MPa to 100 MPa, or 100 MPa to 400 MPa, or 400 MPa to 500 MPa, and so on. Exemplarily, the yield strength of the vibrating plate can also be one of 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, 150 MPa, 200 MPa, 250 MPa, 300 MPa, 350 MPa, 400 MPa, 450 MPa, 500 MPa or any value satisfying the above range.

[0059] In an embodiment of the present invention, the vibrating plate is formed by stamping an aluminum foil material, wherein the stamping is cold stamping or warm stamping with heating, and the temperature of the warm stamping with heating is between 50 °C and 300 °C; the aluminum foil material is made by powder metallurgy and rolling from an aluminum alloy material mixed with silicon carbide powder.

[0060] In some embodiments of the present invention, after the blank is made by powder metallurgy, it is processed through multiple process steps such as hot rolling, annealing, cold rolling, and post-treatment to make a foil, and then the foil is formed by stamping. The powder metallurgy method can make the silicon carbide powder evenly distributed in the aluminum alloy matrix, avoiding composition segregation; the volume fraction of the silicon carbide powder can be freely adjusted, and the composition control is precise; the sintering temperature is lower than the liquidus line, and the alloy is not completely melted, reducing the possibility of interfacial reaction with silicon carbide.

[0061] In some embodiments of the present invention, due to the high strength of the silicon carbide-reinforced aluminum alloy, cracks are likely to occur during cold stamping at room temperature. When hot stamping is carried out by heating, the plasticity of the material is improved and cracks are not easily generated. The temperature for hot stamping can be any value within the range composed of any two values described above. For example, it can be in the range of 50°C to 180°C, or it can be in the range of 180°C to 300°C, and so on. Exemplarily, the temperature for hot stamping can be one of 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 150°C, 180°C, 200°C, 250°C, 280°C, 300°C or any value that satisfies the above range.

[0062] In an embodiment of the present invention, in order to further enhance the stiffness of the diaphragm, reinforcing ribs are formed on at least one surface of the main body portion of the diaphragm. Refer to Figure 3 and Figure 4 As shown, exemplarily, the reinforcing rib 23 can be integrally stamped and formed with the main body portion.

[0063] The second aspect of the present invention provides a diaphragm assembly. Refer to Figure 2 As shown, the key of the diaphragm assembly 20 is that it includes a surround 22 and a diaphragm 21 disposed at the center position of the surround. The diaphragm 21 is the diaphragm described in the first aspect. The surround 22 is integrally injection molded with the diaphragm 21 or connected by an adhesive.

[0064] The third aspect of the present invention provides a sound generating device. Refer to Figure 5 As shown, the sound generating device 100 can be a speaker, which includes a housing 10, a vibration system disposed in the housing 10, and a magnetic circuit system 40 cooperating with the vibration system. The vibration system includes the diaphragm assembly 20 described in the second aspect and a voice coil 30 combined on one side of the diaphragm assembly 20. Among them, the diaphragm assembly 20 includes a surround 22 and a diaphragm 21 disposed at the center position of the surround 22. Among them, the diaphragm 21 is connected to the central portion of the surround 22, and the top of the voice coil is connected to the central portion of the surround 22 or the top of the voice coil is connected to the diaphragm 21.

[0065] Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following embodiments are all conventional biochemical reagents unless otherwise specified; the raw materials, instruments, and equipment used in the following embodiments can all be obtained through the market or can be obtained by existing methods; the dosage of the experimental reagents is the dosage of the reagents in conventional experimental operations unless otherwise specified; the experimental methods are all conventional methods unless otherwise specified. It should be further noted that the following description is only exemplary and not a specific limitation of the present invention.

[0066] Example 1

[0067] The diaphragm for a sound generating device has a thickness of 75 μm. The raw materials for preparing the diaphragm include 3003 aluminum alloy and silicon carbide powder. The volume fraction of the silicon carbide powder in the total volume of the raw materials is 30%. The crystal form of the silicon carbide powder is 6H-type α-SiC, and the D90 particle size of the silicon carbide powder is 5 μm. Among them, the silicon carbide powder has been pre-oxidized.

[0068] The method for preparing the diaphragm is to mix the silicon carbide powder with 3003 aluminum alloy and then use powder metallurgy to form a blank, which is then made into a foil through multiple hot rolling and annealing processes, and then the foil is stamped. Among them, hot stamping is used, and the temperature is 200 °C.

[0069] Example 2

[0070] In Example 2, the outer dimensions and preparation process of the diaphragm are the same as those in Example 1. The difference from Example 1 is only that the silicon carbide powder has not been pre-oxidized.

[0071] Example 3

[0072] In Example 3, the outer dimensions and preparation process of the diaphragm are the same as those in Example 1. The difference from Example 1 is only that a reinforcing rib is integrally stamped on one side surface of the diaphragm.

[0073] Comparative Example 1

[0074] In Comparative Example 1, the diaphragm is an existing 3003-H18 aluminum alloy diaphragm, and the outer dimensions of the diaphragm in Comparative Example 1 are the same as those of the diaphragm in Example 1.

[0075] Comparative Example 2

[0076] In Comparative Example 2, the outer dimensions and preparation process of the diaphragm are the same as those in Example 1. The difference from Example 1 is only that the crystal form of the silicon carbide powder is 3C-type β-SiC.

[0077] Performance Test

[0078] Tensile properties: Tested using an INSTRON universal material testing machine at a rate of 40 mm / min, a gauge length of 100 mm, and a sample width of 15 mm. Among them, the yield strength is taken as the tensile stress corresponding to a strain of 0.2% as the yield strength.

[0079] Specific modulus: Specific modulus = elastic modulus / density.

[0080] Acoustic properties: The diaphragms in the examples and comparative examples are assembled into diaphragm assemblies with the same polyester elastomer diaphragm through acrylic pressure-sensitive adhesive, and the respective diaphragm assemblies are installed in speakers of the same model, and the frequency response curves of each speaker are tested.

[0081] Summary of the Performance of the Vibration Plates in Examples and Comparative Examples in Table 1

[0082] Physical property indexes of the vibrating plate Comparative example 1 Comparative example 2 Example 1 Example 2 Example 3 <![CDATA[Specific modulus / GPa / (g / cm 3 )]]> 25.6 33.8 35.7 34.8 35.8 Yield strength / MPa 76 108 120 116 135

[0083] Combined with Table 1 and Figure 6 the tensile curve shows that for the vibration plate in Example 1, at different strains, the tensile stress is greater than that of the comparative example, and the anti-deformation ability is stronger. This is because 30% of silicon carbide powder is added in Example 1. Silicon carbide has high strength and strong ability to resist deformation during the tensile process. At the same deformation amount, the stress is greater.

[0084] In Example 1, due to the addition of silicon carbide, the density of silicon carbide is about 3.2 g / cm 3 , which is slightly larger than that of aluminum alloy. Therefore, the density of the vibration plate in Example 1 is slightly larger than that of the comparative example. However, due to the addition of silicon carbide powder, it can serve as the crystallization core of aluminum alloy, which is beneficial to the nucleation of the aluminum alloy matrix. Therefore, the grain size in Example 1 is smaller. On the other hand, the thermal expansion coefficients of silicon carbide and the aluminum alloy matrix are different, which increases the dislocation density during processing, causes dislocation tangling, and makes deformation difficult. Therefore, the vibration plate in Example 1 has a higher modulus, and the modulus-density ratio is significantly greater than that of Comparative Example 1.

[0085] In Comparative Example 2, β-silicon carbide with a 3C crystal form is added, and its stability and hardness are worse than those of the 6H-type α-silicon carbide in the examples. Therefore, the improvement effect of the yield strength and the like in Comparative Example 2 is not as obvious as that in Example 1. On the other hand, the silicon carbide used in the examples has a lower cost.

[0086] Combined with Figure 7 it can be seen that in Example 1, due to the slightly larger density, the intermediate frequency is slightly lower than that of Comparative Example 1. However, the modulus-density ratio in Example 1 is high, and the high-frequency cut-off frequency is significantly higher than that of Comparative Example 1. The high-frequency cut-off frequency is about 11.8 K, and the high-frequency cut-off frequency of Comparative Example 1 is about 8.75 K. The loudspeaker assembled with the vibration plate in the example can reproduce sound at a higher frequency.

[0087] The raw materials for preparing the main body of the vibration plate in the present invention include an aluminum alloy material and silicon carbide powder mixed in the aluminum alloy material. By controlling the type of silicon carbide powder to be 6H-type α-SiC and the particle size D90 to be between 0.1 μm and 20 μm, a vibration plate with a high specific modulus and high yield strength is obtained, thereby increasing the high-frequency cut-off frequency of the sound generating device and improving the sound generating effect of the sound generating device.

[0088] In the present invention, through the warm stamping process, the processing accuracy of the vibration plate is improved, and the generation of cracks is reduced.

[0089] The vibration plate of the present invention has a high specific modulus. Therefore, the loudspeaker using the vibration plate of the present invention has a higher high-frequency cut-off frequency.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements 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 diaphragm for a sound generating device, characterized in that, The raw materials for preparing the main body of the vibrating plate include an aluminum alloy material and silicon carbide powder mixed in the aluminum alloy material, and the volume fraction of the silicon carbide powder in the raw materials for preparing the main body is 1% to 50%. The type of the silicon carbide powder is 6H-type α-SiC, and the particle size D90 of the silicon carbide powder is between 0.1 μm and 20 μm.

2. The diaphragm for a sound generating device according to claim 1, wherein, The shape of the silicon carbide powder includes at least one of spherical, flaky, and irregular polyhedral shapes.

3. The diaphragm for a sound generating device according to claim 1, characterized in that, The silicon carbide powder is obtained through modification treatment. The modification treatment includes at least one of pre-oxidation treatment, metal plating treatment, acid treatment, alkali treatment, and silane coupling agent treatment.

4. The diaphragm for a sound generating device according to claim 1, characterized in that, The aluminum alloy material includes one of 1-series, 3-series, 5-series, 6-series, 7-series, and 8-series aluminum alloys.

5. The diaphragm for a sound generating device according to claim 1, wherein An additive element is further provided in the aluminum alloy material, the additive element is at least one of Mg, Si, Ti, Cu, Zr, and Y, and the addition amount of the additive element accounts for 0.1 wt% to 10 wt% of the aluminum alloy material.

6. The diaphragm for a sound generating device according to claim 1, characterized in that, The specific modulus of the vibrating plate is between 25 GPa / (g / cm 3 ) and 50 GPa / (g / cm 3 ); and / or, The density of the vibrating plate is between 2.5 g / cm 3 and 3 g / cm 3 .

7. The diaphragm for a sound generating device according to claim 1, characterized in that, The thickness of the vibrating plate is between 5 μm and 500 μm; and / or The yield strength of the vibrating plate is between 50 MPa and 500 MPa.

8. The diaphragm for a sound generating device according to any one of claims 1 to 7, characterized in that, The vibrating plate is obtained by stamping an aluminum foil material, wherein The stamping is carried out by cold stamping or hot stamping at a temperature between 50 °C and 300 °C; The aluminum foil material is made by powder metallurgy and rolling from an aluminum alloy material mixed with the silicon carbide powder.

9. The diaphragm for a sound generating device according to claim 1, characterized in that, Reinforcing ribs are formed on at least one side surface of the main body of the vibrating plate, and the reinforcing ribs are integrally stamped with the main body.

10. A diaphragm assembly, characterized in that, It includes a surround and a vibrating plate provided at the central position of the surround, and the vibrating plate is the vibrating plate according to any one of claims 1 to 9. The surround and the vibrating plate are integrally injection molded or connected by adhesive bonding.

11. A sound generating device, characterized in that, It includes a vibration system and a magnetic circuit system cooperating with the vibration system, and the vibration system includes the diaphragm assembly according to claim 10 and a voice coil combined on one side of the diaphragm assembly.

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