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, the welding parts are formed by injection molding of polyamide composite materials, and the polyamide composite materials comprise carbon fibers and amorphous polyamide which are mixed together. The mass ratio of the carbon fibers to the amorphous polyamide is 0.10-0.70, the melting enthalpy of the amorphous polyamide is less than or equal to 10J / g, and the glass-transition temperature of the amorphous polyamide is more than or equal to 110 DEG C. According to the shell of the sound production device, the welding part of the first shell and the second shell is formed by injection molding of the polyamide composite material containing the carbon fibers and the amorphous polyamide. The amorphous polyamide does not have a crystalline structure, so that the heat required for melting the welding interface of the two welding parts is lower, the energy required for ultrasonic welding is lower, welding is easier, 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 specifically, to a shell of a sound-generating device, a sound-generating device and an electronic device. Background Art

[0002] The sound module generally includes a module shell and a sound unit disposed in the module shell. The module shell includes a module upper shell and a module lower shell. The sound unit cooperates with the module shell to define a front sound cavity and a rear sound cavity. The module shell is provided with a sound outlet hole connected to the front sound cavity. The module shell is made of metal material and / or plastic material.

[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 of the module and the lower shell of the module is low when ultrasonically welding, there are a large number of cold welds, and the air tightness 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.

[0004] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. Summary of the invention

[0005] An object of the present invention is to provide a new technical solution for a housing of a sound-generating device.

[0006] According to a first aspect of the present invention, a shell of a sound-generating device is provided. The shell includes a first shell and a second shell, the first shell and the second shell are both provided with a welding portion, the welding portion of the first shell and the welding portion of the second shell are ultrasonically welded, the welding portion is injection-molded from a polyamide composite material, the polyamide composite material includes carbon fiber and amorphous polyamide mixed together, the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70, the melting enthalpy of the amorphous polyamide is ≤10J / g, and the glass transition temperature of the amorphous polyamide is ≥110°C.

[0007] Optionally, the amorphous polyamide includes at least one of PA6I, PA 6I / 6T, PA MXDI / 6I, PA MXDI / 12I, PAMXDI, PA MXDI / MXD6, PAMACM10, PA MACM12, PA MACM14, and PA MACM18.

[0008] Optionally, the polyamide composite material includes crystalline polyamide, the carbon fiber and the amorphous polyamide mixed together.

[0009] Optionally, in the polyamide composite material, the mass percentage of the carbon fiber is 9% to 41%;

[0010] And / or, the mass ratio of the crystalline polyamide to the amorphous polyamide is ≤0.46.

[0011] Optionally, the crystalline polyamide includes at least one of PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, and PA1313.

[0012] Optionally, the polyamide composite material further comprises hollow glass microspheres, the mass percentage of the hollow glass microspheres is 1%-20%, and the distribution density of the hollow glass microspheres in the polyamide composite material is 0.1 g / cm 3 -0.8g / cm 3 .

[0013] Optionally, the carbon fiber has a carbon content of 90%-99.99%;

[0014] And / or, the graphitization degree R of the carbon fiber is 0.85-1.15;

[0015] And / or, the length of the carbon fiber is 0.1 mm-1 mm.

[0016] Optionally, at least one of the first shell and the second shell is integrally formed as a welded portion; or

[0017] At least one of the first shell and the second shell further includes a support portion, and the support portion is integrally injection-molded with the welding portion.

[0018] 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.

[0019] Optionally, the support portion further comprises a fiber material, the resin material is mixed with the fiber material, and a mass ratio of the fiber material to the resin material is 0.10-0.70.

[0020] Optionally, the density of the shell is 0.9 g / cm 3 -1.30g / cm 3 ;

[0021] And / or, at least 10% of the area of ​​the shell has a thickness of ≤0.3 mm.

[0022] Optionally, the bending modulus of the shell is 5GPa-40GPa;

[0023] And / or, the bending strength of the shell is 100MPa-400Mpa;

[0024] And / or, the thermal deformation temperature of the shell is ≥100°C.

[0025] Optionally, the housing has a waterproof rating of at least 1 ATM.

[0026] According to a second aspect of the present invention, a sound-generating device is provided, which includes a housing of the sound-generating device described in the present invention.

[0027] According to a third aspect of the present invention, an electronic device is provided, which includes the sound generating device of the present invention.

[0028] In an embodiment of the present invention, the welding part of the first shell and the second shell is formed by injection molding of a polyamide composite material containing carbon fiber and amorphous polyamide. Amorphous polyamide has no crystalline structure, so the heat required for melting the welding interface of the two welding parts is lower, the energy required for ultrasonic welding is lower, and it is easier to weld, thereby improving the welding firmness and airtightness between the first shell and the second shell. Moreover, since amorphous polyamide has no crystalline structure, it has the characteristic of low density, so that a lightweight design of the shell can be achieved. The glass transition temperature of amorphous polyamide is ≥110°C, which can make the shell have a small drop in strength during high-temperature operation and strong structural stability. 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.

[0029] 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 attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0031] Figure 1 is an exploded view of a sound generating device according to an embodiment of the present invention.

[0032] Figure 2 is a cross-sectional view of a sound generating device according to an embodiment of the present invention.

[0033] Figure 3 is a cross-sectional view of another sound-generating device according to an embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 10. First shell; 111. Front sound cavity; 121. Rear sound cavity; 15. Welding part; 16. Support part; 20. Sound unit; 30. PCB; 40. Second shell. DETAILED DESCRIPTION

[0036] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that 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 unless otherwise specifically stated.

[0037] 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.

[0038] 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 as part of the specification.

[0039] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0040] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0041] According to a first embodiment of the present invention, a shell of a sound-generating device is provided. The shell includes a first shell 10 and a second shell 40, wherein the first shell 10 and the second shell 40 are both provided with a welding portion 15, wherein the welding portion 15 of the first shell 10 and the welding portion 15 of the second shell 40 are connected by ultrasonic welding, wherein the welding portion 15 is injection-molded from a polyamide composite material, wherein the polyamide composite material includes carbon fiber and amorphous polyamide mixed together, wherein the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70, the melting enthalpy of the amorphous polyamide is ≤10 J / g, and the glass transition temperature of the amorphous polyamide is ≥110°C.

[0042] Specifically, Figure 1-Figure 3As shown, in a specific embodiment of the present invention, 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 PCB 30. The sound unit 20 is connected to the PCB 30. The PCB 30 is connected to the external circuit. A welding portion 15 is provided at the edge of the first shell 10 and the second shell 40. The welding portion 15 is injection molded of a polyamide composite material containing carbon fiber and amorphous polyamide. 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 the two welding portions 15 are bonded to each other. After curing, the two welding portions 15 are connected together.

[0043] It is understandable that amorphous polyamide is composed of irregularly arranged repeating units and is an amorphous substance. Since there is no crystalline structure in amorphous polyamide, there is no phase interface between the amorphous component and the crystalline component, and the phase interface will cause the dissipation of welding energy during the welding process, resulting in poor welding, such as cold welding, poor air tightness and the like. In the present invention, the polyamide composite material includes amorphous polyamide. Since there is no phase interface between the amorphous component and the crystalline component in amorphous polyamide, the ultrasonic vibration energy can be well transmitted in the material during the ultrasonic welding process, which is conducive to transmitting the ultrasonic vibration energy to the two welding parts 15, and the two welding parts 15 are easier to melt, which effectively improves the firmness of the welding of the first shell 10 and the second shell 40. Since amorphous polyamide has no crystalline structure, the heat required for melting the welding interface of the two welding parts 15 is lower, the energy required for ultrasonic welding is lower, and it is easier to weld, thereby improving the welding strength between the first shell 10 and the second shell 40. Furthermore, 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 air tightness, which can improve the welding air tightness between the first shell 10 and the second shell 40 and improve the waterproof effect of the shell. In addition, since amorphous polyamide has no crystalline structure, it has the characteristic of low density, which is conducive to realizing the lightweight design of the shell.

[0044] Carbon fiber is a high-performance fiber material with high strength and high modulus, which is made from organic fibers (such as polyacrylonitrile, viscose fiber or asphalt) through carbonization and other processes. The density of carbon fiber is lower than that of glass fiber, and the carbon fiber reinforced shell structure strength effect is better. Under the condition of meeting the shell strength and modulus requirements, the amount of carbon fiber added to the polyamide composite material is lower, which is conducive to achieving lightweight shell.

[0045] It should be noted that when the mass ratio of carbon fiber to amorphous polyamide is less than 0.1, the reinforcing effect of carbon fiber on polyamide composite material is poor, and the shell is prone to resonance in the medium frequency stage during the reliability verification of the sound-generating device, resulting in excessive distortion of the medium frequency THD of the sound-generating device; when the mass ratio of carbon fiber to amorphous polyamide is ≥0.1 and ≤0.7, the strength and welding yield of the ultrasonic welding of the welding portion 15 of the first shell 10 and the second shell 40 are significantly increased, and the strength and modulus of the polyamide composite material will increase with the increase of the mass fraction of carbon fiber; however, when the mass ratio of carbon fiber to amorphous polyamide is greater than 0.70, due to the high distribution density of carbon fiber in the polyamide composite material, the amorphous polyamide at the welding interface of the welding portion 15 is relatively small, resulting in poor welding defects such as cold welding at the welding interface, and the welding strength and welding yield decrease. As the mass ratio of carbon fiber to amorphous polyamide continues to increase, the melt index of the polyamide composite material decreases, the viscosity of the melt increases, causing difficulty in glue injection, and the proportion of products with glue deficiency increases. 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. In this embodiment, the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70. Optionally, the mass ratio of the two can be 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70. Within this range, the strength and modulus of the shell can be ensured to be high, and the amount of carbon fiber added can be reduced, the shell is light in weight, and the product yield is high.

[0046] Melting enthalpy is a physical quantity that characterizes the heat consumed by the crystalline structure of a substance during the melting process. Specifically, melting enthalpy is the heat absorbed by the crystalline structure in a substance when it is transformed into an amorphous structure at constant temperature and pressure. The greater the melting enthalpy of a material, the higher the energy consumed when melting. In this embodiment, the melting enthalpy of the amorphous polyamide is ≤10J / g. Within this range, the polyamide composite material consumes less energy when ultrasonic welding is performed, and the melting of the polyamide composite material is easier. Optionally, the melting enthalpy of amorphous polyamide is 2J / g, 3J / g, 4J / g, 5J / g, 6J / g, 7J / g, 8J / g, 9J / g, 10J / g, etc. The above values ​​all make the polyamide composite material consume less energy when ultrasonic welding is performed, and the melting of the polyamide composite material is easier.

[0047] The glass transition temperature refers to the temperature at which an amorphous substance transitions between a glassy state and a highly elastic state. When the glass transition temperature is lower than the glass transition temperature, the material is in a glassy state with high strength and modulus; when the glass transition temperature is reached or higher than the glass transition temperature, the material is in a highly elastic state with strong elasticity. When the glass transition temperature is less than 110°C, the polyamide composite material is prone to deformation at a higher operating temperature, resulting in low structural strength of the first shell 10 and the second shell 40, and poor high temperature resistance of the shell. In this embodiment, the glass transition temperature of the amorphous polyamide is ≥110°C. This makes the connection strength of the first shell 10 and the second shell 40 high at a higher operating temperature, the overall high temperature resistance of the shell is excellent, the structural strength is high, the modulus and strength of the shell decrease little, and the performance stability is excellent during the high temperature reliability test. Optionally, the glass transition temperature of the amorphous polyamide is 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, etc. The above values ​​all result in high connection strength between the first shell 10 and the second shell 40 , and the shell as a whole has excellent high temperature resistance and high structural strength.

[0048] It should be noted that the melting enthalpy of amorphous polyamide can be tested according to the GBT19466.3-2004 standard, and the glass transition temperature can be tested according to the GB / T19466.2-1999 standard.

[0049] The preparation process of the shell of the present invention may include:

[0050] (1) Preparation of polyamide composite materials. Amorphous polyamide is added to a twin-screw extruder from the main feed port for melting. After the amorphous polyamide is melted, carbon fiber is added from the side feed port. The carbon fiber and the molten amorphous polyamide are sheared and mixed uniformly in the extruder, and then extruded into granules.

[0051] (2) Preparation of the shell. The granulated polyamide composite material is melted again during injection molding and then injected into a mold to form the first shell 10 and the second shell 40;

[0052] Alternatively, during injection molding, the support portion 16 is firstly formed by injection molding in a mold, and then the welding portion 15 is formed by injection molding at the edge of the support portion 16 , thereby forming the first shell 10 and the second shell 40 .

[0053] (3) Assemble the sound unit 20 and 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.

[0054] 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 amorphous polyamide is melted. This can effectively reduce the damage of the carbon fiber during the mixing process, thereby enhancing the reinforcement effect of carbon fiber on polyamide composites.

[0055] In an embodiment of the present invention, the welding portion 15 of the first shell 10 and the second shell 40 is formed by injection molding of a polyamide composite material containing carbon fiber and amorphous polyamide. Amorphous polyamide has no crystalline structure, so the heat required for melting the welding interface of the two welding parts is lower, the energy required for ultrasonic welding is lower, and it is easier to weld, thereby improving the welding firmness and airtightness between the first shell 10 and the second shell 40. Moreover, since amorphous polyamide has no crystalline structure, it has the characteristic of low density, so that a lightweight design of the shell can be achieved. The glass transition temperature of amorphous polyamide is ≥110°C, which can make the shell have a small drop in strength during high-temperature operation and strong structural stability. 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.

[0056] In a specific embodiment of the present invention, the amorphous polyamide includes at least one of PA6I, PA 6I / 6T, PA MXDI / 6I, PA MXDI / 12I, PA MXDI, PA MXDI / MXD6, PA MACM10, PA MACM12, PA MACM14, and PA MACM18.

[0057] The above-mentioned amorphous polyamides all have a relatively low melting temperature and can be uniformly mixed with carbon fibers to form a polyamide composite material. During preparation, any one or more of the above-mentioned amorphous polyamides can be mixed together to form a molten substance, and then the carbon fibers and the molten substance are mixed together. For example, the above-mentioned materials are melted in an extruder, and then the carbon fibers are added and the two are mixed together.

[0058] In a specific embodiment of the present invention, the polyamide composite material includes crystalline polyamide, the carbon fiber and the amorphous polyamide mixed together.

[0059] In this embodiment, when preparing the polyamide composite material, first, the crystalline polyamide and the amorphous polyamide are melted and uniformly mixed together. Then, the carbon fiber is added to the mixed crystalline polyamide and the amorphous polyamide, and the mixture is continued to form a uniform polyamide composite material. The addition of the crystalline polyamide can improve the fluidity of the polyamide composite material melt without affecting the ultrasonic welding strength of the first shell and the second shell, so that the injection molding performance of the polyamide composite material is better, and the heat deformation temperature of the polyamide composite material is higher, which further improves the high temperature resistance of the polyamide composite material.

[0060] Optionally, in the polyamide composite material, the mass percentage of the carbon fiber is 9%-41%.

[0061] In a polyamide composite material composed of crystalline polyamide, amorphous polyamide and carbon fiber, when the mass percentage of carbon fiber is greater than 41%, the amount of carbon fiber added is too high, resulting in a high density of the polyamide composite material, which does not meet the lightweight requirements of the shell; conversely, when the mass percentage of carbon fiber is less than 9%, the modulus and strength of the polyamide composite material are low. When the mass percentage of carbon fiber is 9%-41%, the polyamide composite material has both high modulus and strength and low density. Optionally, the mass percentage of carbon fiber is 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 41%, etc., and the above values ​​can make the polyamide composite material have both high modulus and strength and low density.

[0062] Optionally, the mass ratio of the crystalline polyamide to the amorphous polyamide is ≤0.46. In this embodiment, when the mass ratio of the crystalline polyamide to the amorphous polyamide is greater than 0.46, the presence of the crystalline polyamide significantly increases the melting temperature of the polyamide composite material, increases the difficulty of ultrasonic welding, and easily causes defects such as a cold weld between the two welding parts 15 and poor air tightness of the shell. When the mass ratio of the crystalline polyamide to the amorphous polyamide is ≤0.46, the melting temperature of the polyamide composite material is low, making ultrasonic welding easier and the welding of the two welding parts 15 is firm. Optionally, the mass ratio of the crystalline polyamide to the amorphous polyamide is 0.01, 0.05, 0.1, 0.15, 0.20, 0.25, 0.3, 0.35, 0.4, 0.45, 0.46, and the above values ​​can all make the melting temperature of the polyamide composite material low, ultrasonic welding easy, and the overall structural strength of the formed shell high.

[0063] Optionally, the crystalline polyamide includes at least one of PA610, PA612, PA1010, PA11, PA12, PA1212, PA1012, PA1111, PA1213, and PA1313.

[0064] Specifically, the crystalline polyamide is selected from any one of the above materials or a combination of multiple materials, and the above materials can improve the fluidity of the polyamide composite material melt and the high temperature resistance of the polyamide composite material.

[0065] 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%-20%, and the distribution density of the hollow glass microspheres in the polyamide composite material is 0.1 g / cm 3 -0.8g / cm 3 .

[0066] 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 the amorphous polyamide melt; after mixing, a polyamide composite material is finally formed. Since the hollow glass microspheres may be shear-damaged during the mixing process, the hollow glass microspheres are added after the carbon fibers are added to minimize the shear damage of the hollow glass microspheres during the mixing process. The hollow glass microspheres can significantly reduce the density of the polyamide composite material and meet the demand for lightweight shells.

[0067] 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 will decrease, and the shell will be easily damaged in the drop reliability test of the sound-generating device. In this embodiment, the mass percentage of the hollow glass microspheres is 1%-20%. 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 easy to be damaged. Optionally, the mass percentage of the hollow glass microspheres is 1%, 2%, 4%, 6%, 9%, 10%, 12%, 13%, 14%, 16%, 17%, 18%, 19%, 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 easy to be damaged.

[0068] 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 0.1g / cm 3 When the density of the polyamide composite material is reduced, the density reduction effect is not obvious; on the contrary, the distribution density of the hollow glass microspheres is greater than 0.8g / cm 3When 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 0.1 g / cm 3 -0.8g / 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 0.1 g / cm 3 , 0.2g / cm 3 , 0.3g / cm 3 , 0.4g / cm 3 , 0.5g / cm 3 , 0.6g / cm 3 , 0.7g / cm 3 , 0.8g / cm 3 The above values ​​can effectively reduce the density of the polyamide composite material and increase the connection strength of the two welding portions 15, so that the shell is not easily damaged.

[0069] In a specific embodiment of the present invention, the carbon content of the carbon fiber is 90%-99.99%;

[0070] And / or, the graphitization degree R of the carbon fiber is 0.85-1.15;

[0071] And / or, the length of the carbon fiber is 0.1 mm-1 mm.

[0072] 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.

[0073] The graphitization degree R value refers to the value of 1360cm when the Raman spectrum is used to test the carbon fiber. -1 The peak intensity of 1583cm -1The ratio of peak intensity. The degree of graphitization is inversely proportional to the R value. The smaller the R value, the higher the degree of graphitization, the higher the degree of graphitization of the carbon fiber, the higher the modulus along the fiber direction, and the higher the lifting 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 lifting effect on the polyamide composite material is poor. When the R value is less than 0.85, the degree of graphitization 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 low in cost.

[0074] In addition, 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, causing the shell to be damaged in the drop reliability test; when the length of the carbon fiber 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. In this embodiment, the length of the carbon fiber is 0.1mm-1mm. Within this range, 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.

[0075] In a specific embodiment of the present invention, the carbon content of the carbon fiber is 90%-99.99%; the graphitization degree R of the carbon fiber is 0.85-1.15. In this embodiment, the modulus of the polyamide composite material is high, the overall structural strength of the shell is high and the cost is low.

[0076] In a specific embodiment of the present invention, the graphitization degree R of the carbon fiber is 0.85-1.15; the length of the carbon fiber is 0.1mm-1mm. In this embodiment, the polyamide composite material has a high modulus, the overall strength of the shell is high, the cost is low, and the shell is not prone to problems such as exposed fibers and floating fibers during the injection molding process.

[0077] In a specific embodiment of the present invention, the carbon content of the carbon fiber is 90%-99.99%; the length of the carbon fiber is 0.1mm-1mm. In this embodiment, the modulus of the polyamide composite material is high, the overall 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.

[0078] In a specific embodiment of the present invention, the carbon content of the carbon fiber is 90%-99.99%; the graphitization degree R of the carbon fiber is 0.85-1.15; and the length of the carbon fiber is 0.1mm-1mm. In this embodiment, the polyamide composite material has a high modulus, the overall strength of the shell is high, the cost is low, and the shell is not prone to problems such as exposed fibers and floating fibers during the injection molding process.

[0079] In a specific embodiment of the present invention, at least one of the first shell 10 and the second shell 40 has a welded portion 15 as an integral part.

[0080] In other words, in this embodiment, the first shell 10 and / or the second shell 40 are all integrally formed by injection molding of a polyamide-polyamide composite material, wherein the polyamide-polyamide composite material includes carbon fiber and amorphous polyamide mixed together, wherein the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70, the melting enthalpy of the amorphous polyamide is ≤10J / g, and the glass transition temperature of the amorphous polyamide is ≥110°C. 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 integrally formed by injection molding of a polyamide composite material, and a part of the structure of the second shell 40 is integrally formed by injection molding of a polyamide composite material; or, a part of the structure of the first shell 10 is integrally formed by injection molding of a polyamide composite material, and the second shell 40 is entirely integrally formed by injection molding of a polyamide composite material; or, both the first shell 10 and the second shell 40 are integrally formed by injection molding of a polyamide composite material.

[0081] 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.

[0082] 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. The welding portion 15 of the first shell 10 and the second shell 40 is used for ultrasonic welding to connect and form the shell. In this setting, 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.

[0083] 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.

[0084] When preparing the support part 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 set structure according to the sound generation requirements of the sound generation device.

[0085] In a specific embodiment of the present invention, the support portion 16 further includes a fiber material, the resin material and the fiber material are mixed together, and the mass ratio of the fiber material to the resin material is 0.10-0.70.

[0086] 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 0.10, the fiber material has a small improvement on the modulus and strength of the polyamide composite material; on the contrary, when the mass ratio of the fiber material to the resin material is greater than 0.70, the density of the formed polyamide composite material is large and does not meet the requirements of lightweight shell. In this embodiment, the mass ratio of the fiber material to the resin material is 0.10-0.70, within this range, the polyamide composite material has both high strength and modulus and the mass of the formed shell is light. Optionally, the mass ratio of the fiber material to the resin material is 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, and the above values ​​all make the polyamide composite material have both high strength and modulus and the mass of the formed shell is light.

[0087] In a specific embodiment of the present invention, the density of the shell is 0.9 g / cm 3 -1.30g / cm 3 .

[0088] It can be understood that since the amorphous polyamide in the polyamide composite material has no crystalline structure, its density is relatively small, thereby making the overall density of the shell smaller. The overall density of the shell is 0.9 g / cm 3 -1.30g / 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 0.9g / cm 3 , 1.0g / cm 3 , 1.10g / cm 3 , 1.20g / cm 3 , 1.30g / cm 3 The above values ​​can make the shell light and have sufficient modulus and strength.

[0089] In a specific embodiment of the present invention, at least 10% of the area of ​​the shell has a thickness of ≤0.3 mm.

[0090] In this embodiment, the thickness of at least 10% of the surface area of ​​the shell is ≤0.3m. For example, the shell includes a top wall and a side wall, and the area with a thickness of ≤0.3m is located on the top wall and / or the side wall; or the shell is a sheet structure, and the area with a thickness of ≤0.3m is located at least partially on the sheet structure. Optionally, the shell is made of injection molding of a polyamide composite material. Since the polyamide composite material has a high modulus and strength, the shell can be made thinner at least partially, thereby increasing the volume of the internal accommodating cavity of the shell, thereby increasing the volume of the sound cavity of the sound-emitting device, and improving the sound effect of the sound-emitting device.

[0091] In a specific embodiment of the present invention, along the vibration direction of the vibration system of the sound-emitting unit 20, the thickness of at least part of the shell opposite to the sound-emitting unit 20 is ≤0.3mm. This arrangement allows the shell to have a larger space 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 shell is 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, etc., and the above values ​​can all make the space inside the shell larger.

[0092] In addition, in order to make the space of the front sound cavity and / or the rear sound cavity larger, the shell of the prior art usually sets a steel sheet in the vibration direction of the shell to reduce the thickness. In the present invention, since the modulus and strength of the polyamide composite material are large enough, the part of the shell in the vibration direction of the vibration system can be made thinner, for example, the thickness is ≤ 0.3mm, thereby increasing the space of the front sound cavity and / or the rear sound cavity. This method does not need to set a steel sheet, and the shell can be integrally formed by injection molding, which makes the preparation process of the shell simpler.

[0093] In a specific embodiment of the present invention, the bending modulus of the shell is 5 GPa-40 GPa.

[0094] The bending modulus reflects the ability of a material to resist deformation when subjected to a bending load. If the bending modulus of the shell is too low, for example, less than 5GPa, the shell is prone to local vibration, which is easy to resonate with the vibration of the sound-emitting monomer 20, making the sound-emitting device have poor sounding effect; if the bending modulus of the shell is too high, for example, greater than 40GPa, the processing difficulty of the shell will increase and the product yield will decrease. For example, when a shell is prepared using a polyamide composite material, it is necessary to increase the amount of carbon fiber added, for example, the mass ratio of carbon fiber to amorphous polyamide is greater than 0.7, which will cause the viscosity of the amorphous polyamide melt to be too large, and the phenomenon of fiber exposure and lack of glue will easily occur during the injection molding process. In this embodiment, the bending modulus of the shell is 5GPa-40Gpa. Within this range, it 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. Optionally, the bending modulus of the shell is 5GPa, 10GPa, 15GPa, 20GPa, 25GPa, 30GPa, 35GPa, 40Gpa. 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.

[0095] In a specific embodiment of the present invention, the bending strength of the shell is 100 MPa-400 MPa.

[0096] 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 100MPa, the shell is prone to deformation or even fracture when impacted; when the bending strength is higher than 400MPa, the shell has poor fluidity during injection molding and is difficult to process. In this embodiment, the bending strength of the shell is 100MPa-400Mpa. Within this range, the shell is not easily deformed when impacted, and the shell has low processing difficulty and high product yield. Optionally, the bending strength of the shell is 100MPa, 200MPa, 300MPa, 400Mpa, etc. The above values ​​all make the shell have excellent impact resistance and low processing difficulty, and high product yield.

[0097] Optionally, the thermal deformation temperature of the shell is ≥100°C.

[0098] 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 it indicates that the shell can maintain structural stability under higher temperature conditions. In this embodiment, the heat deformation temperature of the shell is ≥100°C, so that the shell has strong high temperature resistance and is not easy to deform during high temperature and high humidity reliability and high power reliability verification. Optionally, the heat deformation temperature of the shell is 110°C, 120°C, 130°C, 140°C, 150°C, etc. The above values ​​all make the shell have strong high temperature resistance and is not easy to deform during high temperature and high humidity reliability and high power reliability verification.

[0099] In a specific embodiment of the present invention, the bending modulus of the shell is 5 GPa-40 Gpa; and / or the bending strength of the shell is 100 MPa-400 MPa; and / or the thermal deformation temperature of the shell is ≥100°C.

[0100] In other words, the performance of the shell at least meets the above two conditions, which significantly improves the shell's anti-deformation ability and high temperature resistance and reduces the processing difficulty.

[0101] In a specific embodiment of the present invention, the waterproof rating of the housing is at least 1 ATM.

[0102] In this embodiment, the welding part 15 of the first shell 10 and the welding part 15 of the second shell 40 are connected by ultrasonic welding, and the welding part 15 is formed by injection molding of a polyamide composite material, and the polyamide composite material includes carbon fiber and amorphous polyamide mixed together, the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70, the melting enthalpy of the amorphous polyamide is ≤10J / g, and the glass transition temperature of the amorphous polyamide is ≥110°C. In this embodiment, since the amorphous polyamide has no crystalline structure and the melting enthalpy of the amorphous polyamide is ≤10J / g, the heat required for melting of the welding interface of the two welding parts 15 is lower, the energy of ultrasonic welding can be lower, it is easier to weld, and it is not easy to have problems such as cold welding and air gap. Amorphous polyamide has a higher glass transition temperature, so that the high temperature resistance of the part where the two welding parts 15 are connected is significantly improved. In addition, the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70, so that the strength and modulus of the welding part 15 are significantly improved. Through the above method, the shell will not be deformed or leak under the water pressure at a depth of 10 meters or more.

[0103] 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.

[0104] like Figure 1-Figure 3As 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 hole. 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 formed by injection molding of a polyamide composite material containing carbon fiber and amorphous polyamide. The welding portions 15 of the first shell 10 and the second shell 40 are connected together by ultrasonic welding.

[0105] The sound-generating device has the characteristics of high structural strength, good high temperature resistance and good sound-generating effect.

[0106] 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 the characteristic of good durability. Optionally, the electronic device is a computer, a mobile phone, a watch, a television, a speaker, an AR device, a VR device, etc.

[0107] 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 only exemplary and not a specific limitation to the present invention.

[0108] Comparative Example 1

[0109] A shell is formed by injection molding of 80 wt % of amorphous PC material and 20 wt % of glass fiber, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device.

[0110] Comparative Example 2

[0111] A shell is formed by injection molding of 80 wt % of PA66 material and 20 wt % of glass fiber, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device.

[0112] Example 1

[0113] A shell is formed by injection molding of 90.9wt% amorphous polyamide and 9.1wt% carbon fiber, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating module. The carbon content of the carbon fiber is 95%, and the graphitization degree R value is 1.01.

[0114] Example 2

[0115] A shell is formed by injection molding of 75.9wt% amorphous polyamide, 9.1wt% carbon fiber and 15wt% hollow glass microspheres, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 99%, and the graphitization degree R value is 0.86.

[0116] Example 3

[0117] A shell is formed by injection molding of 80 wt% amorphous polyamide and 20 wt% carbon fiber, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon fiber has a carbon content of 98% and a graphitization degree R value of 0.89.

[0118] Example 4

[0119] A shell is formed by injection molding of 70 wt% amorphous polyamide and 30 wt% carbon fiber, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon fiber has a carbon content of 91% and a graphitization degree R value of 1.14.

[0120] Example 5

[0121] A shell is formed by injection molding of 58.9wt% amorphous polyamide and 41.1wt% carbon fiber, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device, wherein the carbon content of the carbon fiber is 90% and the graphitization degree R value is 1.15.

[0122] Example 6

[0123] A shell is formed by injection molding 60wt% of amorphous polyamide, 20wt% of carbon fiber and 20wt% of PA610, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 97%, and the graphitization degree R value is 0.96.

[0124] Example 7

[0125] A shell is formed by injection molding 65wt% of amorphous polyamide, 20wt% of carbon fiber and 15wt% of PA612, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 96%, and the graphitization degree R value is 0.99.

[0126] Example 8

[0127] A shell is formed by injection molding 60wt% of amorphous polyamide, 20wt% of carbon fiber and 20wt% of PA1010, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 92%, and the graphitization degree R value is 1.12.

[0128] Example 9

[0129] A shell is formed by injection molding of 55wt% amorphous polyamide, 20wt% carbon fiber and 25wt% PA12, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 93%, and the graphitization degree R value is 1.11.

[0130] Example 10

[0131] A shell is formed by injection molding of 55wt% amorphous polyamide, 20wt% carbon fiber, 10wt% PA12 and 15wt% hollow glass microspheres, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 94%, and the graphitization degree R value is 1.08.

[0132] Embodiment 11

[0133] A shell is formed by injection molding of 70wt% amorphous polyamide, 20wt% carbon fiber and 10wt% PA1212, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 93%, and the graphitization degree R value is 1.11.

[0134] Example 12

[0135] A shell is formed by injection molding of 55wt% amorphous polyamide, 20wt% carbon fiber and 25wt% PA1012, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 93%, and the graphitization degree R value is 1.11.

[0136] Example 13

[0137] A shell is formed by injection molding of 55wt% amorphous polyamide, 20wt% carbon fiber and 25wt% PA1111, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 93%, and the graphitization degree R value is 1.11.

[0138] Embodiment 14

[0139] A shell is formed by injection molding of 55wt% amorphous polyamide, 20wt% carbon fiber and 25wt% PA1213, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 93%, and the graphitization degree R value is 1.11.

[0140] Embodiment 15

[0141] A shell is formed by injection molding of 55wt% amorphous polyamide, 20wt% carbon fiber and 25wt% PA1313, and the shell is assembled with a sound-generating monomer 20 to obtain a sound-generating device. The carbon content of the carbon fiber is 93%, and the graphitization degree R value is 1.11.

[0142] It should be noted that the outer dimensions of the housings in the comparative examples and the embodiments are consistent. The amorphous polyamide in embodiments 1-5 is PA6I, the amorphous polyamide in embodiments 6-10 is PA6I / 6T, and the amorphous polyamide in embodiments 11 to 15 is PA MXDI / 6I. For ease of comparison, the raw material ratios of comparative examples 1 to 2 and embodiments 1 to 15 are shown in Table 1.

[0143] Table 1 - Raw material ratios of the shells of the embodiments and comparative examples

[0144]

[0145]

[0146] The shells of Comparative Examples 1 to 2, the shells of Examples 1 to 15, and the sound-generating devices were tested for melting enthalpy, glass transition temperature, heat deformation temperature, density, bending modulus, bending strength and reliability, respectively. The test results are shown in Tables 2 and 3.

[0147] Table 2 - Performance test comparison table of the housing of the embodiment and the comparative example

[0148]

[0149]

[0150] The test conditions and standards are as follows:

[0151] (1) Flexural modulus and flexural strength test: The test is carried out in accordance with GB / T 9341-2008, the standard for determination of flexural properties of plastics.

[0152] (2) Melt index: Tested in accordance with GB / T 3682.1-2018 Plastics Thermoplastics - Determination of melt mass flow rate (MFR) and melt volume flow rate (MVR) - Part 1: Standard method.

[0153] (3) Heat deformation temperature test: The test shall be conducted in accordance with GB / T 1634.2-2004 Plastics - Determination of deformation temperature - Part 2: Plastics, hard rubber and long fiber reinforced composites.

[0154] (4) Glass transition temperature test method: The test was conducted in accordance with the second part of the glass transition temperature determination of plastics differential scanning calorimetry (DSC) of GB / T19466.2-1999; the ramp rate was 20°C / min.

[0155] (5) Melting enthalpy test method: The test is carried out in accordance with Part 3 of GB / T 19466.3-2004 Plastics Differential Scanning Calorimetry (DSC): Determination of melting and crystallization temperature and enthalpy; the heating and cooling rate is 20°C / min.

[0156] (6) Density test method: Test 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, using the immersion method.

[0157] (7) 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.

[0158] (8) 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.

[0159] (9) 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.

[0160] (10) 2-meter drop reliability test: The sound-generating device is placed at a height of 2 meters and dropped to the ground to cause a collision. The integrity of the shell of the sound-generating device is then observed and its acoustic performance is tested.

[0161] As can be seen from Table 2, the melting enthalpy of the shells of Examples 1-15 is less than 10 J / g. In ultrasonic welding, since the melting temperature of the shells of Examples 1-15 is low, the ultrasonic welding energy consumed is low, and welding is easier. The melting enthalpy of the shell of Comparative Example 1 is small. The melting enthalpy of the shell of Comparative Example 2 is large. When ultrasonic welding is performed, the shell of Comparative Example 2 consumes high ultrasonic welding energy, which easily causes poor welding of the first shell 10 and the second shell 40.

[0162] The glass transition temperature of the shells of Examples 1-15 is ≥110°C, which can reduce the strength of the shells during high-temperature operation and improve structural stability. The glass transition temperature of the shell of Comparative Example 1 is relatively high. The glass transition temperature of the shell of Comparative Example 2 is relatively low.

[0163] The shells of Examples 1-15 and Comparative Examples 1-2 all have high heat deformation temperatures, bending moduli, and bending strengths.

[0164] The density of the shells of Examples 1-15 is ≤1.22 g / cm 3 The density of the shells of Comparative Examples 1-2 is ≥1.33 g / cm 3 , this density does not meet the requirement of lightweight shell.

[0165] It can be seen that the shell of Example 1-15 is injection molded from a polyamide composite material, which includes mixed carbon fiber and amorphous polyamide. The melting enthalpy of amorphous polyamide is low. In ultrasonic welding, ultrasonic vibration can be well transmitted in the material, the shell is easy to melt, and the welding of the shell is more secure. The glass transition temperature, heat deformation temperature, bending modulus, and bending strength of the shell of Example 1-15 are all high, indicating that the structural strength of the shell is high, the strength decreases little during high-temperature operation, and the structural stability is strong. The density of the shell of Example 1-15 is relatively small, meeting the lightweight requirements of the shell.

[0166] Although some properties of the shells of Comparative Examples 1-2, such as bending modulus, bending strength, and heat deformation temperature, meet the requirements, the density of the shells in Comparative Examples 1 and 2 is too large and does not meet the requirements of lightweight shells. In addition, since the shell of Comparative Example 2 is made of crystalline material, there is a phase interface and the melting enthalpy is high. In ultrasonic welding, the shell of Comparative Example 2 has a higher melting temperature, which is easy to cause poor welding.

[0167] In addition to the above tests, ultrasonic flaw detection tests were also performed on the welded parts of the welded portion 15 to evaluate the effect of ultrasonic welding, as shown in Table 3 for details.

[0168] Table 3 - Comparison of ultrasonic welding tests of the shells of the embodiment and the comparative example

[0169] name Ultrasonic flaw detector testing Welding yield Comparative Example 1 Ultrasonic welding OK 100％ Comparative Example 2 Presence of bubbles and voids 20％ Example 1 Ultrasonic welding OK 100％ Example 2 Ultrasonic welding OK 100％ Example 3 Ultrasonic welding OK 100％ Example 4 Ultrasonic welding OK 100％ Example 5 Ultrasonic welding OK 100％ Example 6 Ultrasonic welding OK 100％ Example 7 Ultrasonic welding OK 100％ Example 8 Ultrasonic welding OK 100％ Example 9 Ultrasonic welding OK 100％ Example 10 Ultrasonic welding OK 100％ Embodiment 11 Ultrasonic welding OK 100％ Example 12 Ultrasonic welding OK 100％ Example 13 Ultrasonic welding OK 100％ Embodiment 14 Ultrasonic welding OK 100％ Embodiment 15 Ultrasonic welding OK 100％

[0170] As can be seen from Table 3, the shells of Examples 1 to 15 have all passed the ultrasonic flaw detection test, and the welding yield is 100%, which indicates that since the shells of Examples 1 to 15 are injection molded from polyamide composite materials, the polyamide composite materials include carbon fiber and amorphous polyamide mixed together, which effectively reduces the melting temperature of the welding interface, making ultrasonic welding easier, and the welding of the first shell 10 and the second shell 40 is firm. The shell of Comparative Example 2 uses a crystalline material, which has a high silencing effect, and the energy of ultrasonic welding is not easy to pass through the welding interface. In addition, the melting temperature of the material is high, and bubbles and gaps are easily formed during the ultrasonic welding process, resulting in a low welding yield, which cannot meet the waterproof and reliability requirements.

[0171] Table 4 - Comparison of reliability tests of the sound-generating devices of the embodiment and the comparative example

[0172]

[0173]

[0174] Table 4 is a comparison table of reliability tests of the embodiments and comparative examples. It can be seen from Table 4 that since the shells of embodiments 1-15 are injection molded from a polyamide composite material composed of carbon fiber and amorphous polyamide, the strength and modulus of the shells are relatively large, and the ultrasonic welding strength between the shells is large and the airtightness is good. Therefore, the shells of embodiments 1-15 have passed the tests of high temperature and high humidity reliability, high power reliability, 10m waterproof verification, and 2m drop reliability. Since the PA66 material in comparative example 2 is a crystalline material, the melting enthalpy is relatively high at the phase interface, which affects its ultrasonic welding effect, causing bubbles and gaps in its ultrasonic welding structure, and poor ultrasonic welding, resulting in low connection strength of the two welding parts 15 of the first shell 10 and the second shell 40, which cannot meet the requirements of 10m waterproof verification and 2m drop reliability.

[0175] In summary, the shell of Comparative Example 1 is formed by injection molding of 80wt% PC material and 20wt% glass fiber. Although it can meet the requirements of structural strength, high temperature reliability, air tightness and waterproofness, the density of PC material is relatively large, making it difficult to achieve the lightweight design requirements of the shell. The shell of Comparative Example 2 is formed by injection molding of 80wt% PA66 material and 20wt% glass fiber. Since PA66 material is a crystalline material, the melting enthalpy is relatively high at the phase interface, which affects its ultrasonic welding effect, causing bubbles and gaps in its ultrasonic welding structure, and poor ultrasonic welding, which cannot meet the requirements of waterproofness and reliability. The shells of Examples 1-15 are formed by injection molding of amorphous polyamide and carbon fiber materials. The mass ratio of carbon fiber to the amorphous polyamide is 0.10-0.70, and the melting enthalpy of amorphous polyamide is ≤10J / g. Amorphous polyamide has no crystalline structure, so the heat required for melting the welding interface of the two welding parts is lower, the energy required for ultrasonic welding is lower, and welding is easier, thereby improving the welding firmness and airtightness between the first shell 10 and the second shell 40. In addition, since amorphous polyamide has no crystalline structure, it has a low density, making the density of the shell 0.9g / cm 3 -1.30g / cm 3range, so that a lightweight design of the shell can be achieved. The glass transition temperature of amorphous polyamide is ≥110°C, which can reduce the strength drop of the shell during high-temperature operation and have strong structural stability. 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-40Gpa, 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 100MPa-400Mpa. 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 ≥100°C, which makes the shell have strong high temperature resistance and is not easy to deform in high temperature and high humidity reliability and high power reliability verification tests.

[0176] 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.

[0177] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated 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 will be appreciated by those skilled in the art that the above embodiments may be modified 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, characterized in that: The invention comprises a first shell and a second shell, wherein the first shell and the second shell are both provided with a welding portion, the welding portion of the first shell and the welding portion of the second shell are connected by ultrasonic welding, the welding portion is formed by injection molding of a polyamide composite material, the polyamide composite material comprises mixed carbon fiber and amorphous polyamide, the mass ratio of the carbon fiber to the amorphous polyamide is 0.10-0.70, the melting enthalpy of the amorphous polyamide is ≤10J / g, and the glass transition temperature of the amorphous polyamide is ≥110°C.

2. The housing of the sound-generating device according to claim 1, characterized in that: The amorphous polyamide includes at least one of PA6I, PA6I / 6T, PA MXDI / 6I, PA MXDI / 12I, PA MXDI, PA MXDI / MXD6, PA MACM10, PA MACM12, PA MACM14, and PA MACM18.

3. The housing of the sound-generating device according to claim 1, characterized in that: The polyamide composite material includes the crystalline polyamide, the carbon fiber, and the amorphous polyamide mixed together.

4. The housing of the sound-generating device according to claim 3, characterized in that: In the polyamide composite material, the mass percentage of the carbon fiber is 9% to 41%; And / or, the mass ratio of the crystalline polyamide to the amorphous polyamide is ≤0.

46.

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

6. The housing of the sound-generating device according to claim 1, characterized in that: The polyamide composite material further comprises hollow glass microspheres, the mass percentage of the hollow glass microspheres is 1%-20%, and the distribution density of the hollow glass microspheres in the polyamide composite material is 0.1 g / cm 3 -0.8g / cm 3 .

7. The housing of the sound-generating device according to claim 1, characterized in that: The carbon fiber has a carbon content of 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 0.1 mm-1 mm.

8. The housing of the sound-generating device according to claim 1, 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 further includes a support portion, and the support portion is integrally injection-molded with the welding portion.

9. The housing of the sound-generating device according to claim 8, 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.

10. The housing of the sound-generating device according to claim 9, characterized in that: The support portion further comprises a fiber material, the resin material is mixed with the fiber material, and a mass ratio of the fiber material to the resin material is 0.10-0.

70.

11. The housing of the sound-generating device according to claim 1, characterized in that: The density of the shell is 0.9 g / cm 3 -1.30g / cm 3 ; And / or, at least 10% of the area of ​​the shell has a thickness of ≤0.3 mm.

12. The housing of the sound-generating device according to claim 1, characterized in that: The bending modulus of the shell is 5GPa-40Gpa; And / or, the bending strength of the shell is 100MPa-400Mpa; And / or, the thermal deformation temperature of the shell is ≥100°C.

13. The housing of the sound-generating device according to any one of claims 1 to 12, characterized in that: The housing has a waterproof rating of at least 1ATM.

14. A sound-generating device, characterized in that: A housing comprising a sound-generating device as claimed in any one of claims 1 to 13.

15. An electronic device, characterized in that: Comprising a sound-generating device as claimed in claim 14.

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