Shell of sound production device, sound production device and electronic equipment

Abstract

The invention discloses a shell of a sound production device, the sound production device and electronic equipment. The shell comprises a first shell body and a second shell body, the first shell body and the second shell body are each provided with a welding part, the welding part of the first shell body and the welding part of the second shell body are connected in an ultrasonic welding mode, and the welding parts are formed by injection molding of polyamide composite materials composed of long-chain polyamide and carbon fibers. The mass ratio of the carbon fibers to the long-chain polyamide is 0.11-0.67, the melting temperature of the long-chain polyamide is 150-220 DEG C, and the thickness of the shell is smaller than or equal to 0.3 mm. According to the invention, the welding part of the first shell and the second shell is formed by injection molding of a polyamide composite material. The energy required by crystallization and melting of long-chain polyamide in the polyamide composite material is low, so that ultrasonic welding is easier, the welding quality is better, and the welding firmness and air tightness between the first shell and the second shell can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electroacoustic conversion, and more particularly to a housing of a sound-generating device, a sound-generating device, and an electronic device. Background Art

[0002] The sound module typically includes a module housing and a sound unit housed within the module housing. The module housing comprises an upper module shell and a lower module shell. The sound unit and the module housing cooperate to define a front sound cavity and a rear sound cavity. The module housing is provided with a sound outlet that communicates with the front sound cavity. The module housing is typically made of metal and / or plastic.

[0003] In the related art, a module shell made of a composite of PA66 (nylon) + fiber material is proposed. The module shell has a high structural strength and meets the use requirements of the sound module. When the sound module is assembled, the upper shell of the module is connected to the lower shell of the module by ultrasonic welding. However, due to the high melting enthalpy of the PA66 material, the welding strength of the upper shell and the lower shell of the module is low during ultrasonic welding, there are a large number of cold welds, and the airtightness of the shell is poor; and the density of the material used to prepare the module shell is relatively high, resulting in a large mass of the shell, which does not meet the lightweight design requirements of the sound module. Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the Invention

[0004] An object of the present invention is to provide a new technical solution for a housing of a sound-generating device.

[0005] According to a first aspect of the present invention, a housing for a sound-generating device is provided. The housing comprises a first housing and a second housing, each of the first housing and the second housing having a welded portion connected by ultrasonic welding. The welded portion is injection molded from a polyamide composite material consisting of long-chain polyamide and carbon fiber, wherein the mass ratio of the carbon fiber to the long-chain polyamide is 0.11-0.67, and the melting temperature of the long-chain polyamide is 150°C-220°C. The housing has a thickness of 0.3 mm or less.

[0006] Optionally, in the molecular chain of the long-chain polyamide, two adjacent amide groups are bonded together by continuous methylene groups, and the number of methylene groups bonded together in the continuous methylene groups is greater than or equal to 9.

[0007] Optionally, the long-chain polyamide includes at least one of PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, and PA1313.

[0008] Optionally, the polyamide composite material further comprises hollow glass microspheres, the mass percentage of the hollow glass microspheres is 1% to 20%, and the distribution density of the hollow glass microspheres in the polyamide composite material is 0.45 g / cm 3 -0.75g / cm 3 .

[0009] Optionally, the carbon fiber has a carbon content of 90%-99.99%, and / or a graphitization degree R of the carbon fiber is 0.85-1.15, and / or a length of the carbon fiber is 0.1 mm-1 mm.

[0010] Optionally, the carbon fiber is sizing-treated with a sizing agent. Optionally, the sizing agent includes at least one of a polyester sizing agent, a long-chain polyamide sizing agent, and an epoxy resin sizing agent.

[0011] Optionally, at least one of the first shell and the second shell is integrally formed as a welded portion; or

[0012] At least one of the first shell and the second shell includes a supporting portion, and the supporting portion is injection-molded connected to the welding portion.

[0013] Optionally, the supporting portion includes a resin material, and the resin material includes at least one of PP, PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, PA1313, PPA, PA4T, PA6T, PA9T, PA10T, PA12T, PA46, ABS, PET, PBT, and PC.

[0014] Optionally, the support portion further includes a fiber material, the fiber material includes carbon fiber and / or glass fiber, the resin material is mixed with the fiber material, and the mass ratio of the fiber material to the resin material is 0.25-1.

[0015] Optionally, the density of the shell is 0.85 g / cm 3 -1.25g / cm 3 .

[0016] Optionally, the flexural modulus of the shell is 5 GPa-35 GPa;

[0017] And / or, the bending strength of the shell is 50MPa-350MPa;

[0018] And / or, the thermal deformation temperature of the shell is ≥120°C.

[0019] Optionally, the housing has a waterproof rating of at least 1 ATM.

[0020] According to a second aspect of the present invention, a sound-generating device is provided, which includes the housing of the sound-generating device described in the present invention.

[0021] According to a third aspect of the present invention, an electronic device is provided, which includes the sound-generating device of the present invention.

[0022] In an embodiment of the present invention, the welding portion of the first shell and the second shell is formed by injection molding of a polyamide composite material. The energy required for the crystallization and melting of long-chain polyamide is low, which makes ultrasonic welding easier and the welding quality is better, thereby improving the welding firmness and airtightness between the first shell and the second shell. Moreover, the polyamide composite material includes long-chain polyamide and carbon fiber. The carbon fiber can play a good reinforcing effect and can improve the rigidity and modulus of the shell. Under the premise of meeting the structural strength requirements, the thickness of the shell can be made thinner, and the thickness of the shell is ≤0.3m. Under the same shell size, the volume of the internal accommodating cavity of the shell can be larger, which is conducive to improving the sound effect of the sound-emitting device. In addition, the density of long-chain polyamide is relatively low, which can meet the lightweight requirements of the shell.

[0023] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0025] Figure 1 is an exploded view of a sound-generating device according to an embodiment of the present invention.

[0026] Figure 2 is a cross-sectional view of a sound generating device according to an embodiment of the present invention.

[0027] Figure 3 is a cross-sectional view of another sound-generating device according to an embodiment of the present invention.

[0028] Figure 4 3 are frequency response curves of the sound-generating devices according to Example 1, Example 2 and Comparative Example 3 of the present invention.

[0029] Description of reference numerals:

[0030] 10. First shell; 111. Front acoustic cavity; 121. Rear acoustic cavity; 15. Welding part; 16. Support part; 20. Sound unit; 30. PCB; 40. Second shell. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0033] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0034] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0035] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] According to one embodiment of the present invention, a housing for a sound-generating device is provided. The housing includes a first housing 10 and a second housing 40. Both the first housing 10 and the second housing 40 are provided with a welded portion. The welded portion 15 of the first housing 10 and the welded portion 15 of the second housing 40 are ultrasonically welded. The welded portion 15 is injection molded from a polyamide composite material comprising a mixture of long-chain polyamide and carbon fiber. The mass ratio of the carbon fiber to the long-chain polyamide is 0.11-0.67, and the melting temperature of the long-chain polyamide is 150°C-220°C. The housing has a thickness of 0.3 mm or less.

[0037] Specifically, if Figure 1-Figure 3 As shown, the first shell 10 and the second shell 40 are connected together to form a accommodating cavity therein. The accommodating cavity is used to accommodate the sound unit 20 and the PCB30. The sound unit 20 is connected to the PCB30. The PCB30 is connected to the external circuit. A welding portion 15 is provided on the edge of the first shell 10 and the second shell 40. The welding portion 15 is injection molded from a polyamide composite material. When connected, the two welding portions 15 are arranged opposite to each other, and the two welding portions 15 are melted by ultrasonic welding and bonded to each other. After curing, the two welding portions 15 are connected together. In this embodiment, the polyamide composite material includes a mixture of long-chain polyamide and carbon fiber.

[0038] Long-chain polyamide has a longer carbon chain than short-chain polyamide (such as PA46, PA66, etc.). For example, the average number of carbon atoms in the structural unit of long-chain polyamide is greater than or equal to 9. The melting temperature of long-chain polyamide is relatively low, for example, it can reach 150°C to 220°C. During the ultrasonic welding process, the energy required for the crystallization and melting of long-chain polyamide is low, making ultrasonic welding easier and the welding quality better, thereby improving the welding strength between the first shell 10 and the second shell 40. In addition, the welding consistency of each part of the welding portion 15 is good, and it is not easy to form defects such as cold welding and poor airtightness. It can improve the welding airtightness between the first shell 10 and the second shell 40 and improve the waterproof effect of the shell. In addition, long-chain polyamide has the characteristics of low density, which is conducive to achieving a lightweight design of the shell.

[0039] It should be noted that when the melting temperature of the long-chain polyamide is less than 150°C, the polyamide composite material is prone to deformation at higher operating temperatures, resulting in low structural strength of the first shell 10 and the second shell 40 and poor high-temperature resistance of the shell; and when the melting temperature of the long-chain polyamide is greater than 220°C, due to the excessively high melting temperature of the material, ultrasonic welding is easily difficult, the weld portion 15 forms a cold weld, the airtightness of the shell is poor, and the welding strength is low. The melting temperature of the long-chain polyamide is 150°C-220°C, which can both ensure the high-temperature resistance of the polyamide composite material and avoid the defects of poor ultrasonic welding. Optionally, the melting temperature of the long-chain polyamide is 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, and 220°C. The above values ​​can both ensure the high-temperature resistance of the polyamide composite material and avoid the defects of poor ultrasonic welding.

[0040] Carbon fiber is a high-performance fiber material with high strength and modulus. It is made from organic fibers (such as polyacrylonitrile, viscose, or asphalt) through processes such as carbonization. Carbon fiber has a lower density than glass fiber and offers superior structural strength when reinforced with carbon fiber. While meeting the required strength and modulus, the amount of carbon fiber added to polyamide composites can be reduced, contributing to lighter shells.

[0041] The mass ratio of the carbon fiber to the long-chain polyamide is 0.11-0.67. When the mass ratio of the carbon fiber to the long-chain polyamide is greater than 0.67, due to the high distribution density of the carbon fiber in the polyamide composite material, the long-chain polyamide at the welding interface of the welding portion 15 is relatively small, resulting in defects such as cold welding at the welding interface, and a decrease in welding strength and welding yield. As the mass ratio of the carbon fiber to the long-chain polyamide continues to increase, the melt index of the polyamide composite material decreases, and the viscosity of the melt increases, making it difficult to inject glue, resulting in an increase in the proportion of products with glue shortages. The ultrasonic welding strength and welding yield of the welding portion 15 of the first shell 10 and the second shell 40 will be significantly reduced; on the contrary, when the mass ratio of the carbon fiber to the long-chain polyamide is less than 0.11, the reinforcing effect of the carbon fiber on the polyamide composite material is poor, and the shell is prone to resonance in the intermediate frequency stage during the reliability verification process of the sound-generating device, resulting in excessively high intermediate frequency THD distortion of the sound-generating device. When the mass ratio of the carbon fiber to the long-chain polyamide is 0.11-0.67, the melting temperature of the polyamide composite material is low, making ultrasonic welding easier, the welding of the two welding portions 15 is firm, and the strength and modulus of the shell are high. Optionally, the mass ratio of the carbon fiber to the long-chain polyamide is 0.11, 0.15, 0.20, 0.25, 0.3, 0.35, 0.4, 0.45, 0.46, 0.50, 0.55, 0.60, 0.65, or 0.67. The above values ​​all enable the polyamide composite material to have a low melting temperature, facilitate ultrasonic welding, and have a high structural strength of the overall shell. The polyamide composite material also has a high modulus and strength.

[0042] In this embodiment, the thickness of the shell is ≤0.3m. For example, the shell includes a top wall and side walls, and the thickness of the top wall and side walls is ≤0.3m; or the shell is a sheet-like structure with a thickness of ≤0.3m. It is understood that the shell is injection-molded from a polyamide composite material. Due to the high modulus and strength of this polyamide composite material, the shell can be made thinner. Due to the smaller thickness of the shell, the volume of the internal housing cavity of the shell can be larger for the same shell size, which is beneficial for improving the sound effect of the sound-emitting device.

[0043] In addition, this configuration can increase the vibration space of the housing in the vibration direction of the vibration system, allowing the vibration amplitude of the sound-emitting unit 20 to be larger, effectively improving the sound effect. Optionally, the thickness of the housing is 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, etc., all of which can increase the space inside the housing.

[0044] The preparation process of the shell of the present invention may include:

[0045] (1) Preparation of polyamide composite materials. Long-chain polyamide is fed into a twin-screw extruder from the main feed port for melting. After the long-chain polyamide is melted, carbon fiber is added from the side feed port. The carbon fiber and the melted long-chain polyamide are shear-mixed in the extruder and then extruded into pellets.

[0046] (2) Preparation of the shell. The granulated polyamide composite material is re-melted during injection molding and then injected into a mold to form the first shell 10 and the second shell 40;

[0047] Alternatively, during injection molding, the support portion 16 is firstly formed in a mold by injection molding, and then the welding portion 15 is formed at the edge of the support portion 16 by injection molding, thereby forming the first shell 10 and the second shell 40 .

[0048] (3) Assemble the sound unit 20, PCB 30 and other components into the accommodation cavity formed by the first shell 10 and the second shell 40. Then, align the two welding parts 15 of the first shell 10 and the second shell 40 and perform ultrasonic welding to connect the two welding parts 15 together.

[0049] It should be noted that the length-to-diameter ratio of carbon fiber is relatively large and its ability to resist shear is not high, so it is usually necessary to add carbon fiber after the long-chain polyamide is melted. This can effectively reduce the damage of the carbon fiber during the mixing process, thereby improving the reinforcement effect of carbon fiber on polyamide composite materials.

[0050] In an embodiment of the present invention, the welding portion 15 of the first shell 10 and the second shell 40 is injection molded from a polyamide composite material. The energy required for the crystallization and melting of long-chain polyamide is low, which makes ultrasonic welding easier and the welding quality is better, thereby improving the welding firmness and airtightness between the first shell 10 and the second shell 40. Moreover, the polyamide composite material includes long-chain polyamide and carbon fiber. The carbon fiber can have a good reinforcement effect and can improve the rigidity and modulus of the shell. Under the premise of meeting the structural strength requirements, the thickness of the shell can be made thinner, and the thickness of the shell is ≤0.3m. Under the same shell size, the volume of the internal accommodating cavity of the shell can be larger, which is beneficial to improving the sound effect of the sound-emitting device. In addition, the density of long-chain polyamide is relatively low, which can meet the lightweight requirements of the shell.

[0051] In a specific embodiment of the present invention, in the molecular chain of the long-chain polyamide, two adjacent amide groups are bonded together by continuous methylene groups, and the number of methylene groups bonded together in the continuous methylene groups is greater than or equal to 9.

[0052] In this embodiment, the long-chain polyamide comprises multiple bonded polyamide groups and multiple continuous methylene groups. The continuous methylene groups comprise multiple bonded methylene groups. The multiple methylene groups are in a chain-like structure. The continuous methylene groups are bonded between two adjacent amide groups. The greater the number of bonded methylene groups in the continuous methylene groups, the lower the melting point and melting temperature of the long-chain polyamide; the fewer the number of bonded methylene groups in the continuous methylene groups, the higher the melting point and melting temperature of the long-chain polyamide. When the number of bonded methylene groups in the continuous methylene groups is less than 9, the long-chain polyamide has a high melting point, which results in a high melting temperature of the polyamide composite material. This requires high ultrasonic welding energy, which can easily cause defects such as cold welds and bubbles during ultrasonic welding, resulting in poor welding. When the number of bonded methylene groups in the continuous methylene groups is greater than or equal to 9, the long-chain polyamide has a lower melting temperature, for example, reaching 150°C to 220°C. This requires less ultrasonic welding energy, makes ultrasonic welding easier, and improves weld quality. Optionally, the number of methylene groups connected together in the continuous methylene groups is 10, 11, 12, 13, 14, 15, 16, 20, 30, etc. This structural unit allows the long-chain polyamide to have a lower melting temperature and high ultrasonic welding quality.

[0053] In a specific embodiment of the present invention, the long-chain polyamide includes at least one of PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, and PA1313.

[0054] The aforementioned long-chain polyamides all have relatively low melting temperatures and can be uniformly mixed with carbon fibers to form a polyamide composite material. During preparation, any one or more of the aforementioned long-chain polyamides can be mixed together to form a molten material, and then the carbon fibers and the molten material are mixed together. For example, the aforementioned materials can be melted in an extruder, and then the carbon fibers are added and mixed together.

[0055] In a specific embodiment of the present invention, the polyamide composite material further comprises hollow glass microspheres, the mass percentage of the hollow glass microspheres is 1% to 20%, and the distribution density of the hollow glass microspheres in the polyamide composite material is 0.45 g / cm 3 -0.75g / cm 3 .

[0056] In this embodiment, the polyamide composite material also includes hollow glass microspheres. For example, when preparing the polyamide composite material, hollow glass microspheres and carbon fibers are added to a long-chain polyamide melt; after mixing, the polyamide composite material is ultimately formed. Because the hollow glass microspheres may be shear-damaged during the mixing process, the hollow glass microspheres are added after the carbon fibers to minimize shear damage to the hollow glass microspheres during mixing. Hollow glass microspheres can significantly reduce the density of the polyamide composite material, meeting the demand for lightweight housings.

[0057] In the polyamide composite material, the mass percentage of the hollow glass microspheres is 1%-20%. It should be noted that when the mass percentage of the hollow glass microspheres in the polyamide composite material is less than 1%, the effect of reducing the density of the polyamide composite material is not obvious; on the contrary, when the mass percentage of the hollow glass microspheres in the polyamide composite material is greater than 20%, the impact resistance of the polyamide composite material is reduced, and the shell is easily damaged in the drop reliability test of the sound-generating device. When the mass percentage of the hollow glass microspheres is 1%-20%, the density of the polyamide composite material can be effectively reduced, and the connection strength of the two welding parts 15 is high, and the shell is not easily damaged. Optionally, the mass percentage of the hollow glass microspheres is 1%, 2%, 4%, 6%, 9%, 10%, 12%, 13%, 14%, 16%, 17%, 18%, 19%, or 20%. The above values ​​can effectively reduce the density of the polyamide composite material, and the connection strength of the two welding parts 15 is high, and the shell is not easily damaged.

[0058] The distribution density of hollow glass microspheres in polyamide composite materials refers to the mass of hollow glass microspheres per unit volume of polyamide composite materials. The distribution density of hollow glass microspheres is less than 0.45g / cm 3 When the density of the review material is reduced, the effect of reducing the density is not obvious; on the contrary, the distribution density of the hollow glass microspheres is greater than 0.75g / cm 3 When the hollow glass microspheres are placed in the polyamide composite material, the impact resistance of the composite material will be reduced. In the drop reliability test of the sound-generating device, the shell is easily damaged. In this embodiment, the distribution density of the hollow glass microspheres in the polyamide composite material is 0.45 g / cm 3 -0.75 / cm 3 Within this range, the density of the polyamide composite material can be effectively reduced, and the connection strength of the two welding parts 15 is high, and the shell is not easily damaged. Optionally, the distribution density of the hollow glass microspheres in the polyamide composite material is 0.45g / cm 3 , 0.5g / cm 3 , 0.6g / cm 3 , 0.7g / cm 3 , 0.75g / cm3 The above values ​​can effectively reduce the density of the polyamide composite material and increase the connection strength of the two welding portions 15, making the shell less prone to damage.

[0059] In a specific embodiment of the present invention, the carbon content of the carbon fiber is 90%-99.99%.

[0060] And / or, the graphitization degree R of the carbon fiber is 0.85-1.15,

[0061] And / or, the length of the carbon fiber is 0.1 mm-1 mm.

[0062] Specifically, the lower the carbon content of the carbon fiber, the lower the modulus of the carbon fiber; conversely, the higher the carbon content of the carbon fiber, the higher the modulus of the carbon fiber. In this embodiment, the carbon content of the carbon fiber is 90%-99.99%. Within the range, under the same mass content conditions, the modulus of the polyamide composite material is high and the structural strength of the shell as a whole is high. Optionally, the carbon content of the carbon fiber is 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.99%, etc. The above values ​​can all make the modulus of the polyamide composite material high and the structural strength of the shell as a whole high.

[0063] The graphitization degree R value refers to the value of 1360cm when the carbon fiber is tested by Raman spectroscopy. -1 The peak intensity of 1583cm -1 The ratio of peak intensity. Graphitization degree is inversely proportional to R value. The smaller the R value, the higher the graphitization degree, the higher the graphitization degree of the carbon fiber, the higher the modulus along the fiber direction, and the higher the improvement effect on the modulus of the polyamide composite material. When the R value is greater than 1.15, the graphitization degree of the carbon fiber is too small, and the modulus improvement effect on the polyamide composite material is poor. When the R value is less than 0.85, the graphitization degree of the carbon fiber is high, and the raw material requirements and processing technology requirements for the carbon fiber are both high, which increases the cost. In this embodiment, the graphitization degree R value of the carbon fiber is 0.85-1.15. Within this range, the modulus of the polyamide composite material is high and the cost of the carbon fiber is low, and the cost of the polyamide composite material is low. Optionally, the graphitization degree R value of the carbon fiber is 0.85, 0.9, 0.95, 1, 1.05, 1.1, 1.15. The above values ​​can all make the modulus of the polyamide composite material high and the cost low.

[0064] In this embodiment, the length of the carbon fiber is 0.1mm-1mm. When the length of the carbon fiber is less than 0.1mm, the strength of the shell will decrease at the same carbon fiber content, resulting in damage to the shell in the drop reliability test; when the carbon fiber length is greater than 1mm, during the injection molding process, the shell is prone to problems such as exposed fibers and floating fibers, affecting the product yield. When the length of the carbon fiber is 0.1mm-1mm, the strength of the shell is high, and the shell is not prone to problems such as exposed fibers and floating fibers during the injection molding process, and the product yield is high. Optionally, the length of the carbon fiber is 0.1mm, 0.2mm, 0.3mm, 0.2mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc. The above values ​​can all make the shell strong, and the shell is not prone to problems such as exposed fibers and floating fibers during the injection molding process.

[0065] In a specific embodiment of the present invention, the carbon fiber has a carbon content of 90%-99.99% and a graphitization degree R of 0.85-1.15. In this embodiment, the polyamide composite material has a high modulus, the overall structural strength of the housing is high, and the cost is low.

[0066] In one embodiment of the present invention, the carbon fibers have a graphitization degree R of 0.85-1.15 and a length of 0.1 mm-1 mm. In this embodiment, the polyamide composite material has a high modulus, high overall strength of the housing, and low cost, and is less prone to problems such as exposed or floating fibers during the injection molding process.

[0067] In a specific embodiment of the present invention, the carbon fiber has a carbon content of 90% to 99.99% and a length of 0.1 mm to 1 mm. In this embodiment, the polyamide composite material has a high modulus, the overall strength of the housing is high, and the housing is less susceptible to problems such as exposed or floating fibers during the injection molding process.

[0068] In a specific embodiment of the present invention, the carbon fibers have a carbon content of 90% to 99.99%, a degree of graphitization (R) of 0.85 to 1.15, and a length of 0.1 mm to 1 mm. In this embodiment, the polyamide composite material has a high modulus, high overall strength, and low cost, and is less prone to fiber exposure and floating during the injection molding process.

[0069] In a specific embodiment of the present invention, the carbon fibers are sizing-treated with a sizing agent, and the sizing agent includes at least one of a polyester sizing agent, a long-chain polyamide sizing agent, and an epoxy resin sizing agent.

[0070] In this embodiment, the surface of carbon fiber has inertia, poor compatibility with long-chain polyamide, and low bonding strength. In the polyamide composite material preparation process, it is necessary to carry out surface treatment on the surface of carbon fiber to improve the compatibility of carbon fiber and long-chain polyamide. Carbon fiber is sizing treated using a sizing agent. Sizing agent includes at least one of a polyester sizing agent, a long-chain polyamide sizing agent, and a polyolefin sizing agent. Above-mentioned sizing agent can all promote the bonding strength of carbon fiber and long-chain polyamide, improve the compatibility of carbon fiber and long-chain polyamide.

[0071] In a specific embodiment of the present invention, the entirety of at least one of the first shell and the second shell is a welded portion.

[0072] In other words, in this embodiment, the first shell 10 and / or the second shell 40 are all made of a polyamide composite material by integral injection molding, and the polyamide composite material includes a mixture of long-chain polyamide and carbon fiber, the mass ratio of the carbon fiber to the long-chain polyamide is 0.11-0.67, the melting temperature of the long-chain polyamide is 150°C-220°C, and the thickness of the shell is ≤0.3mm. As mentioned above, the shell has the characteristics of high modulus, high strength, light weight, easy ultrasonic welding, and high welding yield. For example, the first shell 10 is entirely made of a polyamide composite material by integral injection molding, and part of the structure of the second shell 40 is also made of a polyamide composite material by integral injection molding; or, part of the structure of the first shell 10 is made of a polyamide composite material by integral injection molding, and the second shell 40 is entirely made of a polyamide composite material by integral injection molding; or, both the first shell 10 and the second shell 40 are entirely made of a polyamide composite material by integral injection molding.

[0073] In a specific embodiment of the present invention, at least one of the first shell 10 and the second shell 40 further includes a support portion 16 , and the support portion 16 and the welding portion 15 are integrally injection-molded.

[0074] Specifically, if Figure 1 、 Figure 2 As shown, the first shell 10 and / or the second shell 40 are formed by double-shot molding. For example, the support portion 16 is formed in one shot, and the welding portion 15 is formed on the support portion 16 in the second shot. After curing, the support portion 16 and the welding portion 15 are connected together. In this embodiment, the support portion 16 can be processed into a set shape according to actual needs to meet the sound requirements of different sound-emitting devices. The welding portion 15 is formed at the edge of the support portion 16, and the welding portion 15 of the first shell 10 and the second shell 40 is used for ultrasonic welding to connect to form a shell. In this arrangement, different parts of the first shell 10 and / or the second shell 40 are made of different materials according to different functions, and the different materials are molded by integral injection molding. The processing technology of the first shell 10 and / or the second shell 40 is simple and the structural strength is high.

[0075] In a specific embodiment of the present invention, the supporting portion 16 includes a resin material, and the resin material includes at least one of PP, PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, PA1313, PPA, PA4T, PA6T, PA9T, PA10T, PA12T, PA46, ABS, PET, PBT, and PC.

[0076] When preparing the support portion 16, any one of the above materials can be selected, or at least two of the above materials can be mixed together. The above materials can be processed into a predetermined structure according to the sound generation requirements of the sound generation device.

[0077] In a specific embodiment of the present invention, the support portion further comprises a fiber material, the fiber material comprises carbon fiber and / or glass fiber, the resin material is mixed with the fiber material, and the mass ratio of the fiber material to the resin material is 0.25-1.

[0078] In this embodiment, the fiber material is, for example, carbon fiber and / or glass fiber. The resin material and the fiber material are mixed together to form a polyamide composite material, and the fiber material can significantly improve the modulus and strength of the polyamide composite material. When the mass ratio of the fiber material to the resin material is less than 0.25, the fiber material has little effect on the modulus and strength of the polyamide composite material; conversely, when the mass ratio of the fiber material to the resin material is greater than 1, the density of the formed polyamide composite material is large, which does not meet the requirements for lightweight shell. In this embodiment, the mass ratio of the fiber material to the resin material is 0.25-1. Within this range, the polyamide composite material has both high strength and modulus and the mass of the shell formed is light. Optionally, the mass ratio of the fiber material to the resin material is 0.25, 0.30, 0.40, 0.50, 0.60, 0.70, 0.8, 0.9, 1, etc., and the above values ​​all make the polyamide composite material have both high strength and modulus and the mass of the shell formed is light.

[0079] In a specific embodiment of the present invention, the density of the shell is 0.85 g / cm 3 -1.25g / cm 3 .

[0080] Specifically, in this embodiment, the density of the long-chain polyamide is relatively low, so that the density of the entire shell is 0.85 g / cm 3 -1.25g / cm 3Within this range, at the same volume, the shell has a smaller mass and sufficient modulus and strength, meeting the requirement of lightweight shell. Optionally, the density of the shell is 0.85g / cm 3 , 1.0g / cm 3 , 1.10g / cm 3 , 1.20g / cm 3 , 1.25g / cm 3 The above values ​​can make the shell light in weight and have sufficient modulus and strength.

[0081] In a specific embodiment of the present invention, the bending modulus of the shell is 5 GPa-35 GPa.

[0082] The flexural modulus reflects a material's ability to resist deformation when subjected to a bending load. If the housing's flexural modulus is too low, for example, below 5 GPa, localized vibrations can easily occur, potentially resonating with the vibrations of the sound-generating unit 20 and resulting in poor sound quality. If the housing's flexural modulus is too high, for example, greater than 35 GPa, it can increase the difficulty of processing the housing and reduce product yield. For example, when using a polyamide composite material to manufacture the housing, increasing the amount of carbon fiber added—for example, a carbon fiber to long-chain polyamide mass ratio greater than 0.67—can result in excessive viscosity of the long-chain polyamide melt, making it prone to fiber delamination and adhesive defects during the injection molding process. In this embodiment, the housing's flexural modulus is between 5 GPa and 35 GPa. Within this range, resonance between the housing and the sound-generating unit 20 is avoided, while also reducing the difficulty of processing the housing, minimizing housing defects, and improving product yield. Optionally, the housing's flexural modulus is 5 GPa, 10 GPa, 15 GPa, 20 GPa, 25 GPa, 30 GPa, or 35 GPa. The above values ​​can avoid resonance between the shell and the sound-emitting unit 20 and reduce the difficulty of processing the shell, thereby improving the product yield.

[0083] In a specific embodiment of the present invention, the bending strength of the shell is 50 MPa-350 MPa.

[0084] Bending strength is the maximum normal stress that a material can withstand when it reaches a specified deflection or breaks under a bending load. When the bending strength of the shell is lower than 50MPa, the shell is prone to deformation or even fracture when impacted; when the bending strength is higher than 350MPa, the shell has poor fluidity during injection molding and is difficult to process. In this embodiment, the bending strength of the shell is 50MPa-350MPa. Within this range, the shell is not easily deformed when impacted, and the shell is easy to process with high product yield. Optionally, the bending strength of the shell is 50MPa, 100MPa, 200MPa, 300MPa, 350MPa, etc. The above values ​​all result in the shell having excellent impact resistance, low processing difficulty, and high product yield.

[0085] In a specific embodiment of the present invention, the thermal deformation temperature of the shell is ≥120°C.

[0086] The heat deformation temperature reflects the ability of the material to resist deformation under heat and load conditions. The higher the heat deformation temperature of the shell, the more likely it is that the shell can maintain structural stability under higher conditions. In this embodiment, the heat deformation temperature of the shell is ≥120°C, so that the shell has strong high temperature resistance and is not easily deformed during high temperature and high humidity reliability and high power reliability verification. Optionally, the heat deformation temperature of the shell is 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 200°C, etc. The above values ​​all make the shell have strong high temperature resistance and are not easily deformed during high temperature and high humidity reliability and high power reliability verification.

[0087] In a specific embodiment of the present invention, the bending modulus of the shell is 5 GPa-35 GPa; and / or the bending strength of the shell is 50 MPa-350 MPa; and / or the thermal deformation temperature of the shell is ≥120°C.

[0088] In other words, the performance of the shell at least meets the above two conditions, which significantly improves the shell's deformation resistance and high temperature resistance and reduces processing difficulty.

[0089] In a specific embodiment of the present invention, the housing has a waterproof rating of at least 1 ATM.

[0090] In this embodiment, the welding portion 15 of the first shell 10 and the welding portion 15 of the second shell 40 are connected by ultrasonic welding. The welding portion 15 is injection molded from a polyamide composite material. The polyamide composite material includes mixed carbon fibers and long-chain polyamide. The melting temperature of the long-chain polyamide is 150°C-220°C. Therefore, the heat required to melt the welding interface of the two welding portions 15 is lower, the energy of ultrasonic welding can be lower, and welding is easier, and problems such as cold welding and air gaps are less likely to occur. In addition, the mass ratio of the carbon fibers to the long-chain polyamide is 0.11-0.67, which significantly improves the strength and modulus of the welding portion 15. In this way, the shell will not deform or leak at a water pressure of 10 meters.

[0091] According to a second embodiment of the present invention, a sound-generating device is provided, which includes the housing of the sound-generating device described in the present invention.

[0092] like Figure 1-Figure 3 As shown, the sound-emitting device of the present invention includes a shell, a sound-emitting unit 20 and a PCB30. The shell includes a first shell 10 and a second shell 40. The first shell 10 and the second shell 40 are connected together to form a accommodating cavity therein. The accommodating cavity is used to accommodate the sound-emitting unit 20 and at least part of the PCB30. A front sound cavity 111 is formed between the first shell 10 and the sound-emitting unit 20. The front sound cavity 111 has a sound outlet. A rear sound cavity 121 is formed between the second shell 40 and the sound-emitting unit 20. The sound-emitting unit 20 is connected to the PCB30. The PCB30 is connected to an external circuit. The edges of the first shell 10 and the second shell 40 are both provided with a welding portion 15. The welding portion 15 is made of injection molding of a polyamide composite material containing carbon fiber and long-chain polyamide. The welding portion 15 of the first shell 10 and the second shell 40 are connected together by ultrasonic welding.

[0093] The sound-generating device has the characteristics of high structural strength, good high-temperature resistance and good sound effect.

[0094] According to a third embodiment of the present invention, an electronic device is provided. The electronic device includes the sound-generating device of the present invention. The electronic device has good durability. Optionally, the electronic device is a computer, a mobile phone, a watch, a television, a speaker, an AR device, a VR device, a vehicle, etc.

[0095] The shell of the sound-generating device and the sound-generating device according to the embodiment of the present invention are described in detail below in combination with specific embodiments and comparative examples. It is worth noting that the following description is merely exemplary and does not specifically limit the present invention.

[0096] Comparative Example 1

[0097] A shell is formed by injection molding using 80 wt % of PC material and 20 wt % of glass fiber, and the shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0098] Comparative Example 2

[0099] A shell is formed by injection molding using 80 wt% of PA66 material and 20 wt% of glass fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0100] Comparative Example 3

[0101] A shell is formed by injection molding using 90 wt% of PA66 material and 10 wt% of glass fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0102] Example 1

[0103] A shell is formed by injection molding using 90 wt% PA12 and 10 wt% carbon fiber, and the obtained shell is assembled with the sound unit 20 to obtain a sound module.

[0104] Example 2

[0105] A shell is formed by injection molding using 80 wt% of PA12 and 20 wt% of carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0106] Example 3

[0107] A shell is formed by injection molding using 70 wt% of PA12 and 30 wt% of carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0108] Example 4

[0109] A shell is formed by injection molding using 60 wt% of PA12 and 40 wt% of carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0110] Example 5

[0111] A shell is formed by injection molding using 80 wt% of PA610 and 20 wt% of carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0112] Example 6

[0113] A shell is formed by injection molding using 70 wt% of PA612 and 30 wt% of carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0114] Example 7

[0115] A shell is formed by injection molding using 60 wt% PA1010 and 40 wt% carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0116] Example 8

[0117] A shell is formed by injection molding using 80 wt% PA11 and 20 wt% carbon fiber, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0118] It should be noted that the outer dimensions of the housings in the comparative examples and the examples are consistent. For ease of comparison, the raw material proportions of comparative examples 1-3 and examples 1-8 are shown in Table 1.

[0119] Table 1 - Raw material ratios of the shells of the embodiments and comparative examples

[0120]

[0121] The shells of comparative examples 1-3 and the shells of embodiments 1-8 were tested for heat deformation temperature, density, bending modulus, bending strength and reliability, and the test results are shown in Table 2, Table 3 and Table 4.

[0122] Table 2 - Performance test comparison of the housings of the embodiment and the comparative example

[0123] name Heat deformation temperature density flexural modulus Bending strength ℃ <![CDATA[g / cm 3 ]]> GPa MPa Comparative Example 1 120 1.35 5.5 150 Comparative Example 2 220 1.33 10 230 Comparative Example 3 220 1.21 4.5 150 Example 1 160 1.06 5.7 110 Example 2 165 1.12 8.5 120 Example 3 165 1.17 15 145 Example 4 165 1.22 23 160 Example 5 200 1.2 12 180 Example 6 195 1.25 19 230 Example 7 182 1.23 24 180 Example 8 165 1.13 9 115

[0124] The test conditions and standards are as follows:

[0125] (1) Flexural modulus and flexural strength test: The test shall be conducted in accordance with GB / T 9341-2008, Determination of Flexural Properties of Plastics.

[0126] (2) Heat deformation temperature test: The test shall be carried out in accordance with GB / T 1634.2-2004 Plastics - Determination of heat deformation temperature - Part 2: Plastics, hard rubber and long fiber reinforced polyamide composites.

[0127] (3) Density test method: The test shall be carried out in accordance with GB / T 1033.1-2008 Plastics - Determination of density of non-foamed plastics - Part 1: Immersion method, liquid pycnometer method and titration method, and the immersion method shall be used for testing.

[0128] (4) High temperature and high humidity reliability test: The sound-generating device is placed in a test environment with a temperature of 85°C and a humidity of 85% for 48 hours, and then the sound-generating device is removed to test its acoustic performance.

[0129] (5) High-power reliability test: The sound-generating device is operated at 1.1 times the rated power for 72 hours, and then its acoustic performance is tested.

[0130] (6) 10-meter waterproof verification test: Place the sound-generating device in water at a depth of 10 meters for 30 minutes, then take it out and test its acoustic performance.

[0131] (7) 2-meter drop reliability test: Place the sound-generating device at a height of 2 meters and let it fall to the ground to cause a collision. Then observe whether the shell of the sound-generating device is intact and test its acoustic performance.

[0132] As can be seen from Table 2, the heat deformation temperature of the shells of Examples 1-8 and the heat deformation temperature of the shells of Comparative Examples 1-3 are both ≥120°C. The flexural strength of the shells of Examples 1-8 and the flexural strength of the shells of Comparative Examples 1-3 are both between 50 MPa and 350 MPa. The flexural modulus of the shells of Examples 1-8 and the flexural modulus of the shells of Comparative Examples 1-2 are both between 5 GPa and 35 GPa. The mass percentage of glass fiber contained in the shell of Comparative Example 3 is relatively small, only 10 wt%. The glass fiber has insufficient strength-enhancing effect on the polyamide composite material, resulting in a low flexural modulus of the shell of Comparative Example 3.

[0133] In addition, the shell densities of Examples 1-8 and Comparative Example 3 are all ≤1.23 g / cm 3 The density meets the requirement of lightweight shell. The shell of comparative example 1 contains PC material, which has a higher density, so the density of the shell of comparative example 1 is higher, reaching 1.35g / cm 3 The density does not meet the requirement of lightweight shell. The shell of Comparative Example 2 contains PA66 material. PA66 is a short-chain crystalline material with a high density. Therefore, the density of the shell of Comparative Example 2 is high, reaching 1.35g / cm 3 , this density does not meet the requirements of lightweight shell.

[0134] As can be seen, the shells of Examples 1-8 are injection-molded from a polyamide composite material comprising a mixture of carbon fibers and long-chain polyamide. The long-chain polyamide has a low melting temperature, making the shells easily meltable and providing a more secure weld. The shells of Examples 1-8 all exhibit high heat deformation temperatures, flexural moduli, and flexural strength, demonstrating high structural strength, minimal strength loss during high-temperature operation, and strong structural stability. The shells of Examples 1-8 all have low densities, meeting the requirements for lightweight shells.

[0135] Although certain properties of the shells of Examples 1-3, such as the bending modulus, bending strength, and thermal deformation temperature of the shells of Example 1-2, and the bending modulus, thermal deformation temperature, and density of the shells of Example 3 meet the requirements, the density of the shells of Example 1-2 is too large and does not meet the requirements of lightweight shells; the bending modulus of the shells of Example 3 is low, and local parts of the shells are prone to vibration, which is easy to resonate with the vibration of the sound-emitting unit 20, resulting in poor sound effect of the sound-emitting device.

[0136] In addition to the above tests, the process performance of the shells of Examples 1-8 and Comparative Examples 1-3 were also tested, as shown in Tables 3 and Figure 4 .

[0137] Table 3 - Comparison of process performance tests of the shells of the embodiment and the comparative example

[0138]

[0139] As can be seen from Table 3, the yield rate of the injection molding process of the housings of Examples 1-8 and Comparative Examples 1-3 is relatively high, and the yield rate of the injection molding process reaches 100%.

[0140] The ultrasonic welding yield rate for Examples 1-8 reached 100%. This indicates that because the housings of Examples 1-8 utilize polyamide composite materials, which utilize long-chain polyamides with low melting temperatures, ultrasonic welding of the first housing 10 and the second housing 40 is easier and less likely to result in defects such as cold welds and poor airtightness. The housing of Comparative Example 1 utilizes an amorphous PC and glass fiber composite material, which has a low melting temperature, resulting in a high ultrasonic welding yield rate.

[0141] The shells of Comparative Examples 2-3 are made of a PA66 and glass fiber composite material. PA66 is a short-chain, crystalline polyamide with a high melting point and high melting temperature. The energy of ultrasonic welding makes it difficult to melt the material, and cold welds and bubbles are easily formed during the ultrasonic welding process, resulting in a low welding yield.

[0142] Table 4 - Comparison of reliability tests of the sound-generating devices of the embodiment and the comparative example

[0143]

[0144]

[0145] Table 4 is a comparison table of reliability tests of the embodiments and comparative examples. As can be seen from Table 4, the housings of Examples 1-8 and Comparative Example 1 all passed the tests of high temperature and high humidity reliability, high power reliability, 10m waterproof verification, and 2m drop reliability.

[0146] The housing of Comparative Example 2 contains PA66 material. PA66 is a short-chain polyamide with an excessively high water absorption rate. The sound-generating device easily absorbs large amounts of water during high-temperature and high-humidity reliability testing, causing deformation and failure of the housing. Invisible weld defects are also prone to occur at the welds. During the 10m waterproofing test, stress concentration caused cracking at the welds under water pressure. Furthermore, during the 2m drop reliability test, rapid impacts easily cause localized stress concentration in the housing, leading to cracking and failure at the welds. The housing of Comparative Example 3 contains PA66 material. PA66 is a short-chain polyamide with an excessively high water absorption rate. The sound-generating device easily absorbs large amounts of water during high-temperature and high-humidity reliability testing, causing deformation and failure at the housing. Invisible weld defects are also prone to occur at the welds. During the 10m waterproofing test, stress concentration caused cracking at the welds under water pressure. Furthermore, during the 2m drop reliability test, rapid impacts easily cause localized stress concentration in the housing, leading to cracking and failure at the welds. Since the shell of comparative example 3 has a higher mass percentage of PA66 material, the bending modulus of the shell is lower, and local parts of the shell are prone to vibration, which easily resonates with the vibration of the sound-emitting unit 20, resulting in poor sound effect of the sound-emitting device, and therefore failed the high-power reliability test.

[0147] Figure 4 : The frequency response curves of the sound-generating devices according to Example 1, Example 2, and Comparative Example 3 of the present invention. The horizontal axis is frequency, in Hz; the vertical axis is response, in dB; a is the frequency response curve of the sound-generating device of Example 1; b is the frequency response curve of the sound-generating device of Example 2; and c is the frequency response curve of the sound-generating device of Comparative Example 3. Figure 4 As can be seen, curves a and b have a high degree of overlap. Within the 100Hz-1000Hz range, the response increases with increasing frequency; after 1000Hz, the response remains above 90dB. Curve c essentially overlaps with curves a and b before 10000Hz, but after 10000Hz, a downward spike appears. This indicates that the insufficient bending modulus of the housing in Comparative Example 3 results in insufficient housing rigidity, causing resonance between the housing and the sound-emitting unit in the high-frequency range. This results in a downward spike in the frequency response curve and distorted sound from the sound-emitting device.

[0148] In summary, the shell of Comparative Example 1, which is formed by injection molding 80wt% PC material and 20wt% glass fiber, can meet the requirements of structural strength, reliability, airtightness, and waterproofing. However, the high density of PC material makes it difficult to achieve the lightweight design requirements of the shell. The shell of Comparative Example 2, which is formed by injection molding 80wt% PA66 material and 20wt% glass fiber, can meet the requirements of structural strength and high power reliability. However, due to the high melting point and melting temperature of PA66 material in the shell of Comparative Example 2, the energy of ultrasonic welding is difficult to melt the material, and cold welds and bubbles are easily formed during the ultrasonic welding process, resulting in a low welding yield. PA66 is a short-chain polyamide with high water absorption. The sound-generating device easily absorbs large amounts of water during high-temperature and high-humidity reliability testing, causing deformation and failure of the housing. Furthermore, weld defects are prone to occur. During the 10m water resistance test, stress concentration in welds caused cracking under water pressure. Furthermore, during the 2m drop reliability test, rapid impact can cause localized stress concentration in the housing, leading to cracking and failure in welds. The housing of Comparative Example 3 is injection molded from 90wt% PA66 and 10wt% glass fiber. This material has a high melting point and high melting temperature, making it difficult for ultrasonic welding energy to melt it. This makes it prone to forming cold welds and bubbles during the ultrasonic welding process, resulting in a low welding yield. PA66 is a short-chain polyamide with high water absorption. The sound-generating device easily absorbed large amounts of water during high-temperature and high-humidity reliability testing, causing deformation and failure of the housing. Invisible weld defects were also common at welds. During the 10m waterproofing test, stress concentration caused cracking in welds under water pressure. Furthermore, during the 2m drop reliability test, rapid impacts easily caused localized stress concentration in the housing, leading to cracking and failure in welds. Furthermore, due to the low glass fiber content in the housing of Comparative Example 3, the housing had a low flexural modulus and could not meet high-power reliability requirements.

[0149] The shells of Examples 1-8 are formed by injection molding long-chain polyamide and carbon fiber materials. The mass ratio of carbon fiber to the long-chain polyamide is 0.11-0.67. The melting temperature of long-chain polyamide is low, and the energy required for ultrasonic welding is lower, making it easier to weld. This can improve the welding firmness and airtightness between the first shell 10 and the second shell 40. In addition, since long-chain polyamide has a low density, the density of the shell is 0.85g / cm 3 -1.25g / cm 3range, thereby achieving a lightweight design of the shell. The melting temperature of long-chain polyamide is 150°C-220°C, and the energy required for the crystallization and melting of long-chain polyamide is low, which makes ultrasonic welding easier and the welding quality of the shell is better. Moreover, the above-mentioned polyamide composite material includes carbon fiber material, which has a high modulus and strength, thereby improving the structural strength of the shell. In addition, the bending modulus of the shell is in the range of 5GPa-35GPa, which can not only avoid the resonance between the shell and the sound-emitting monomer 20, but also reduce the processing difficulty of the shell, reduce shell defects, and improve product yield. The bending strength of the shell is in the range of 50MPa-435MPa. When the shell is impacted, it is not easy to deform, and the processing difficulty of the shell is small, and the product yield is high. The heat deformation temperature of the shell is ≥120°C, which can make the shell have little strength loss during high-temperature operation and strong structural stability. The shells of Examples 1-8 have strong strength, modulus, and high-temperature resistance, and are not easy to deform in high-temperature and high-humidity reliability, high-power reliability verification, 10m waterproof verification, and 2m drop reliability tests.

[0150] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0151] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A housing of a sound-generating device, It is characterized in that It includes a first shell and a second shell, the first shell and the second shell are both provided with a welding part, the welding part of the first shell and the welding part of the second shell are connected by ultrasonic welding, the welding part is injection molded from a polyamide composite material consisting of long-chain polyamide and carbon fiber, the mass ratio of the carbon fiber to the long-chain polyamide is 0.11-0.67, the melting temperature of the long-chain polyamide is 150℃-220℃, and the thickness of the shell is ≤0.3mm.

2. The housing of the sound-generating device according to claim 1, It is characterized in that In the molecular chain of the long-chain polyamide, two adjacent amide groups are bonded together by continuous methylene groups, and the number of methylene groups bonded together in the continuous methylene groups is greater than or equal to 9.

3. The housing of the sound-generating device according to claim 1, It is characterized in that The long-chain polyamide includes at least one of PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, and PA1313.

4. The housing of the sound-generating device according to claim 1, It is characterized in that The polyamide composite material further comprises hollow glass microspheres, the mass percentage of the hollow glass microspheres is 1% to 20%, and the distribution density of the hollow glass microspheres in the polyamide composite material is 0.45 g / cm 3 -0.75g / cm 3 .

5. The housing of the sound-generating device according to claim 1, It is characterized in that The carbon content of the carbon fiber is 90%-99.99%, and / or the graphitization degree R of the carbon fiber is 0.85-1.15, and / or the length of the carbon fiber is 0.1mm-1mm.

6. The housing of the sound-generating device according to claim 1, It is characterized in that The carbon fiber is sizing treated with a sizing agent, and the sizing agent includes at least one of a polyester sizing agent, a long-chain polyamide sizing agent and an epoxy resin sizing agent.

7. The housing of the sound-generating device according to claim 1, It is characterized in that The entirety of at least one of the first shell and the second shell is a welded portion; or At least one of the first shell and the second shell includes a supporting portion, and the supporting portion is injection-moldedly connected to the welding portion.

8. The housing of the sound-generating device according to claim 7, It is characterized in that The supporting portion includes a resin material, and the resin material includes at least one of PP, PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, PA1313, PPA, PA4T, PA6T, PA9T, PA10T, PA12T, PA46, ABS, PET, PBT, and PC.

9. The housing of the sound-generating device according to claim 8, It is characterized in that The support part further comprises a fiber material, wherein the fiber material comprises carbon fiber and / or glass fiber, and the resin material is mixed with the fiber material, and a mass ratio of the fiber material to the resin material is 0.25-1.

10. The housing of the sound-generating device according to claim 1, It is characterized in that The density of the shell is 0.85 g / cm 3 -1.25g / cm 3 .

11. The housing of the sound-generating device according to claim 1, It is characterized in that The bending modulus of the shell is 5GPa-35GPa; And / or, the bending strength of the shell is 50MPa-350MPa; And / or, the heat deformation temperature of the shell is ≥120°C.

12. A housing of a sound-generating device according to any one of claims 1 to 11, It is characterized in that The housing has a waterproof rating of at least 1ATM.

13. A sound-generating device, It is characterized in that A shell comprising the sound-generating device as described in any one of claims 1-12.

14. An electronic device, It is characterized in that Includes the sound-generating device as claimed in claim 13.

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