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 reinforcing part, the thickness of the reinforcing part is smaller than or equal to 0.3 mm, the reinforcing part is formed by injection molding of a polyamide composite material composed of carbon fibers and polyamide, in the reinforcing part, the mass ratio of the carbon fibers to the polyamide is 0.42-1, the density of the reinforcing part ranges from 1.2 g / cm < 3 > to 1.45 g / cm < 3 >, and the bending modulus of the reinforcing part ranges from 20 GPa to 40 GPa. According to the shell, the reinforcing part is formed by injection molding of the polyamide composite material, the polyamide composite material comprises the carbon fibers and the polyamide which are mixed together, the bending modulus of the reinforcing part is 20-40 GPa, the carbon fibers can remarkably improve the strength and modulus of the polyamide composite material, and the shell does not need to be thinned and improve the structural strength through injection molding of a steel sheet; the shell has good structural consistency and sealing performance, the structural strength meets the actual use requirement, the machining process of the shell is simplified, and the product yield is high.

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] In the related art, the shell of the speaker module is usually made of PC + glass fiber reinforced plastic material and steel sheet inserts. The shell has good structural strength and low price. However, its disadvantage is that the density of the steel sheet insert is too high. For example, the density of the steel sheet insert is 7.8g / cm 3 Too high a density is not conducive to the lightweight requirements of speaker modules and electronic products.

[0003] In addition, the joints between the plastic material and the steel insert in the shell of the speaker module are not firmly bonded, which can easily lead to waterproof failure. The shell of the speaker module is made by injection molding. Among them, the shrinkage rates of the plastic material and the steel insert are different, which can easily cause the shell to deform, leading to difficulties in shell assembly and failure of speaker module performance.

[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 comprises a reinforcing portion, the thickness of the reinforcing portion is ≤0.3 mm, the reinforcing portion is formed by injection molding of a polyamide composite material composed of carbon fiber and polyamide, wherein in the reinforcing portion, the mass ratio of the carbon fiber to the polyamide is 0.42-1, and the density of the reinforcing portion is 1.2 g / cm 3 -1.45g / cm 3 , the bending modulus of the reinforcement portion is 20GPa-40GPa.

[0007] Optionally, the polyamide includes semi-aromatic polyamide, and the semi-aromatic polyamide includes at least one of PPA, PA46, PA4T, PA5T, PA6T, PA9T, PA10T, and PA12T.

[0008] Optionally, the carbon content of the carbon fiber is 92%-99.99%, and / or the graphitization degree R value of the carbon fiber is 0.8-1.05, and / or the length of the carbon fiber is 0.1mm-1mm, and / or the orientation angle of the graphite crystallites of the carbon fiber is ≤25°.

[0009] Optionally, the carbon fiber is sizing treated with a sizing agent, and the sizing agent includes at least one of a polyamide sizing agent, a polyurethane sizing agent, and an epoxy resin sizing agent.

[0010] Optionally, an accommodating cavity is provided inside the shell, and at least a part of the wall of the accommodating cavity is formed by the reinforcement part.

[0011] Optionally, the accommodating cavity comprises a front acoustic cavity and a rear acoustic cavity, and at least part of the wall of the front acoustic cavity and / or the rear acoustic cavity is formed by the reinforcement portion.

[0012] Optionally, the entire shell is composed of the reinforcement part.

[0013] Optionally, the shell further includes a base portion, and the base portion and the reinforcement portion are integrally injection molded.

[0014] Optionally, the base 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.

[0015] Optionally, the base 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.

[0016] Optionally, the bending strength of the reinforcement portion is 200MPa-450MPa;

[0017] And / or, the thermal deformation temperature of the reinforcement portion is ≥250°C.

[0018] According to a second aspect of the present invention, a sound-generating device is provided, which comprises a housing of the sound-generating device of the present invention.

[0019] Optionally, the sound-emitting device further comprises a sound-emitting unit disposed in the shell, the sound-emitting unit comprises a vibration system, and along the vibration direction of the vibration system, at least a portion of the shell opposite to the sound-emitting unit is composed of the reinforcement portion.

[0020] According to a third aspect of the present invention, an electronic device is provided, which includes the sound generating device of the present invention.

[0021] In an embodiment of the present invention, the shell of the sound-generating device includes a reinforcing portion, wherein the reinforcing portion is a polyamide composite material, wherein the polyamide composite material includes carbon fiber and polyamide mixed together, in the reinforcing portion, the mass ratio of the carbon fiber to the polyamide is 0.42-1, and the density of the reinforcing portion is 1.2 g / cm 3 -1.45g / cm 3 , the bending modulus of the reinforcement is 20GPa-40GPa. Since the polyamide composite material used to make the reinforcement includes carbon fiber and polyamide mixed together, the bending modulus of the reinforcement is as high as 20GPa-40GPa. On the premise of meeting the structural strength requirements of the shell, the thickness of the reinforcement can be made thinner, and the thickness of the reinforcement is ≤0.3mm, so that the volume of the housing cavity in the shell is increased, and the sound effect of the sound-generating device is improved. Carbon fiber can significantly improve the strength, modulus and thermal conductivity of polyamide composite materials. In reliability verification, it is not easy for the shell to resonate with the sound-generating monomer. The shell has a high modulus and strength and a good thermal conductivity. In addition, the shell is injection molded with a polyamide composite material, and the overall consistency is good. There will be no problems such as shell deformation and waterproof failure due to the injection of steel sheets on the plastic shell. In addition, the shell does not require injection steel sheets for thinning, heat conduction and maintaining structural strength, thereby simplifying the processing technology of the shell and having a high product yield.

[0022] 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

[0023] 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.

[0024] Figure 1 is a cross-sectional view of a sound generating device according to an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 10. First shell; 11. Top wall; 111. Front sound cavity; 121. Rear sound cavity; 15. Side wall edge; 20. Sound unit; 30. PCB; 40. Second shell; 41. Bottom wall. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] According to one embodiment of the present invention, a shell of a sound-generating device is provided. The shell includes a reinforcement portion, the thickness of the reinforcement portion is ≤0.3 mm, the reinforcement portion is a polyamide composite material, wherein the polyamide composite material includes carbon fiber and polyamide mixed together, in the reinforcement portion, the mass ratio of the carbon fiber to the polyamide is 0.42-1, and the density of the reinforcement portion is 1.2 g / cm 3 -1.45g / cm 3 , the bending modulus of the reinforcement portion is 20GPa-40GPa.

[0033] Specifically, Figure 1 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-emitting monomer 20 and the PCB30. The sound-emitting monomer 20 is connected to the PCB30. A front sound cavity is formed between the first shell 10 and the sound-emitting monomer 20, and the front sound cavity has a sound outlet. The sound outlet is used to radiate sound waves outward. The front sound cavity can adjust the mid- and high-frequency effects of the sound-emitting device. A rear sound cavity is formed between the second shell 40 and the sound-emitting monomer 20. The rear sound cavity can adjust the low-frequency effect of the sound-emitting device. PCB30 is connected to an external circuit. The first shell 10 includes a top wall 11 and a first side wall, and the second shell 40 includes a bottom wall 41 and a second side wall. The side wall edges 15 of the first side wall and the second side wall are ultrasonically welded or adhesively bonded. The reinforcement portion is arranged on at least a portion of the top wall 11, the bottom wall 41, the first side wall, and the second side wall. Further, the top wall 11, the bottom wall 41, the first side wall and / or the second side wall are integrally reinforced. Alternatively, one of the first shell 10 and the second shell 40 is a flat plate structure. The reinforcement portion is provided at least partially on the first shell 10 and the second shell 40 .

[0034] In this embodiment, since the polyamide composite material of the reinforcement part includes carbon fiber and polyamide mixed together, the bending modulus of the reinforcement part is as high as 20GPa-40GPa. Under the premise of meeting the structural strength requirements of the shell, the thickness of the reinforcement part can be made thinner, and the thickness of the reinforcement part is ≤0.3mm. Since the thickness of the reinforcement part is small, the space of the housing cavity in the shell is larger, and the volume of the front sound cavity and / or the rear sound cavity is larger, so that the sound effect of the sound-generating device can be more effectively adjusted.

[0035] In addition, the reinforcement is a polyamide composite material. The polyamide composite material includes carbon fiber and polyamide mixed together. Polyamide, also known as nylon, is a high molecular polymer containing repeated amide groups (-NHCO-) ​​in the main chain, which can be prepared by reactions such as lactam ring-opening polymerization or diamine and dibasic acid polycondensation. Polyamide has the characteristics of high strength, high rigidity, high heat resistance and high toughness, so that the modulus and strength of polyamide polymer are high. Carbon fiber is a high-performance fiber material with high strength and high modulus, which is prepared by organic fibers (such as polyacrylonitrile, viscose fiber or asphalt) through carbonization and other process treatments. Carbon fiber has high strength and modulus in the fiber direction and 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 in the polyamide composite material is lower, which is conducive to achieving the lightweight of the shell. And the thermal conductivity of carbon fiber is good, so that the thermal conductivity of the shell is good, so that the strength, modulus and thermal conductivity of the polyamide composite material are excellent.

[0036] The mass ratio of the carbon fiber to the polyamide is 0.42-1. When the mass ratio of the carbon fiber to the polyamide is greater than 1, due to the high distribution density of the carbon fiber in the polyamide composite material, the viscosity of the polyamide composite material is too high, and the lack of glue is likely to occur during the injection molding process; on the contrary, when the mass ratio of the carbon fiber to the polyamide is less than 0.42, 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 THD distortion of the intermediate frequency of the sound-generating device. When the mass ratio of the carbon fiber to the polyamide is 0.42-1, the shell is not prone to lack of glue during the injection molding process and the shell has high strength and modulus. Optionally, the mass ratio of the carbon fiber to the polyamide is 0.42, 0.45, 0.46, 0.50, 0.55, 0.60, 0.65, 0.67, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, etc. The above values ​​can make the polyamide composite material less prone to defects, the overall structural strength of the formed shell is high, and the polyamide composite material has high modulus and strength.

[0037] Since the density of polyamide is relatively low, the density of the reinforcement part after being compounded with carbon fiber is 1.2 g / cm 3 -1.45g / cm 3 . Density of reinforcement part <1.2g / cm 3 When the content of carbon fiber in the polyamide composite material is too high, it is easy to cause the shell to be short of glue during the injection molding process; on the contrary, the density of the reinforcement part is greater than 1.45g / cm 3 When the weight of the shell is too large, it is easy to cause the shell to be too heavy, which does not meet the requirement of lightweight shell. In this embodiment, the density of the reinforcement part is 1.2g / cm 3 -1.45g / cm 3 Within this range, the shell has few defects and meets the requirement of lightweight shell. Optionally, the density of the reinforcement part is 1.2g / cm 3 , 1.25g / cm 3 , 1.3g / cm 3 , 1.35g / cm 3 , 1.4g / cm 3 , 1.45g / cm 3 The above values ​​can reduce the defects of the shell and meet the requirements of lightweight shell.

[0038] The bending modulus of the reinforcement is 20GPa-40GPa. The bending modulus reflects the ability of the material to resist deformation when subjected to a bending load. If the bending modulus of the shell is too low, for example, less than 20GPa, the shell is prone to local vibration, which is easy to resonate with the vibration of the sound-emitting monomer 20, resulting in poor sound effect of the sound-emitting device; 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 polyamide is greater than 1, which will cause the viscosity of the 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 20GPa-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. In addition, since the bending modulus of the reinforcement part is large, the reinforcement part can be made thinner, for example, the thickness is ≤0.3mm, so that the volume of the accommodating cavity is larger, and the shell has sufficient structural strength, so there is no need to increase the strength of the shell by injection molding steel sheets, which makes the processing technology of the shell simpler. Optionally, the bending modulus of the shell is 20GPa, 25GPa, 30GPa, 35GPa, 40GPa, etc. The above values ​​can avoid the resonance between the shell and the sound-emitting monomer 20 and reduce the processing difficulty of the shell, thereby improving the product yield.

[0039] The preparation process of the shell of the present invention may include:

[0040] (1) Preparation of polyamide composite materials. Polyamide is added to a twin-screw extruder from the main feed port for melting. After the polyamide is melted, carbon fiber is added from the side feed port. The carbon fiber and the molten polyamide are sheared and mixed uniformly in the extruder and then extruded into granules.

[0041] (2) Preparation of Shells 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 .

[0042] (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 side wall edges 15 of the first shell 10 and the second shell 40, and perform ultrasonic welding or bonding to connect the two side wall edges 15 together.

[0043] 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 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.

[0044] In an embodiment of the present invention, the shell of the sound-generating device includes a reinforcing portion, wherein the reinforcing portion is a polyamide composite material, wherein the polyamide composite material includes carbon fiber and polyamide mixed together, in the reinforcing portion, the mass ratio of the carbon fiber to the polyamide is 0.42-1, and the density of the reinforcing portion is 1.2 g / cm 3 -1.45g / cm 3 , the bending modulus of the reinforcement is 20GPa-40GPa. Since the polyamide composite material used to make the reinforcement includes carbon fiber and polyamide mixed together, the bending modulus of the reinforcement is as high as 20GPa-40GPa. Under the premise of meeting the structural strength requirements of the shell, the thickness of the reinforcement can be made thinner, and the thickness of the reinforcement is ≤0.3mm, so that the volume of the accommodating cavity in the shell is increased, and the sound effect of the sound-emitting device is improved. Carbon fiber can significantly improve the strength, modulus and thermal conductivity of polyamide composite materials. In reliability verification, it is not easy for the shell and the sound-emitting monomer 20 to resonate, and the shell has a good thermal conductivity. It has high modulus and strength, and good thermal conductivity. In addition, the shell does not require injection-molded steel sheets for thinning, heat conduction and maintaining structural strength, thereby avoiding the phenomenon of cracking between the steel sheet and the injection-molded material, simplifying the processing technology of the shell, and having a high product yield.

[0045] In a specific embodiment of the present invention, the polyamide includes semi-aromatic polyamide, and the semi-aromatic polyamide includes at least one of PPA, PA46, PA4T, PA5T, PA6T, PA9T, PA10T, and PA12T.

[0046] Semi-aromatic polyamide is a polymer material obtained by polycondensation of aliphatic diamine or dibasic acid with aromatic dibasic acid or diamine. Semi-aromatic polyamide has the characteristics of good high temperature resistance and high initial modulus, which makes the polyamide composite material have higher stiffness and modulus and better high temperature resistance. Optionally, the semi-aromatic polyamide includes at least one of PPA, PA46, PA4T, PA5T, PA6T, PA9T, PA10T, and PA12T. In other words, any one of the above semi-aromatic polyamides can be selected, or a mixture of at least two of the above semi-aromatic polyamides can be selected.

[0047] In a specific embodiment of the present invention, the carbon content of the carbon fiber is 92%-99.99%, and / or the graphitization degree R value of the carbon fiber is 0.8-1.05, and / or the length of the carbon fiber is 0.1mm-1mm, and / or the orientation angle of the graphite crystallites of the carbon fiber is ≤25°.

[0048] 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 92%-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 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.99%, etc. The above values ​​can all make the modulus and strength of the polyamide composite material high, and the structural strength of the shell as a whole is high.

[0049] In addition, 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. In this embodiment, the length of the carbon fiber is 0.1mm-1mm. Within this range, the structural 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 structural strength of the shell high, and the shell is not prone to problems such as exposed fibers and floating fibers during the injection molding process.

[0050] The orientation angle of graphite crystallites refers to the angle between the crystal plane of graphite crystallites and the fiber direction. The smaller the orientation angle of graphite crystallites in carbon fiber, the higher the modulus in the fiber direction, and the higher the lifting effect on the modulus of the polyamide composite material. In this embodiment, the orientation angle of graphite crystallites in carbon fiber is ≤25°. Within this range, the modulus of carbon fiber in the fiber direction is high, so that the modulus of polyamide composite material is high. Optionally, the orientation angle of graphite crystallites in carbon fiber is 15°, 17°, 19°, 20°, 22°, 24°, 25°, etc. The above values ​​all make the modulus of polyamide composite material high.

[0051] In other embodiments, the carbon fiber meets at least two of the above conditions. The polyamide composite material has high modulus and strength, and is not prone to problems such as exposed fibers and floating fibers.

[0052] In a specific embodiment of the present invention, the carbon fiber is sizing treated with a sizing agent, and the sizing agent includes at least one of a polyamide sizing agent, a polyurethane sizing agent, and an epoxy resin sizing agent.

[0053] In this embodiment, the surface of carbon fiber is inert, has poor compatibility with polyamide, and has low bonding strength. In the polyamide composite material preparation process, the surface of carbon fiber needs to be surface treated to improve the compatibility of carbon fiber and polyamide. Carbon fiber is sizing treated with a sizing agent. The sizing agent includes at least one of a polyamide sizing agent, a polyurethane sizing agent, and an epoxy resin sizing agent. The above sizing agents can all improve the bonding strength of carbon fiber and polyamide, and improve the compatibility of carbon fiber and polyamide.

[0054] In a specific embodiment of the present invention, an accommodating cavity is provided inside the shell, and at least a part of the wall of the accommodating cavity is formed by the reinforcing portion.

[0055] like Figure 1As shown, the first shell 10 and the second shell 40 are connected to form a accommodating cavity inside the shell. A sound-emitting unit 20 and a PCB 030 are arranged in the accommodating cavity. The wall portion of the accommodating cavity includes a top wall 11, a bottom wall 41, a first side wall, and a second side wall. The side wall edges 15 of the first side wall and the second side wall are ultrasonically welded or adhesively bonded. The reinforcement portion is arranged on at least a part of the top wall 11, the bottom wall 41, the first side wall and / or the second side wall. This arrangement can significantly increase the volume of the accommodating cavity, thereby being able to more effectively adjust the sound effect of the sound-emitting device.

[0056] In a specific embodiment of the present invention, the cavity includes a front acoustic cavity and a rear acoustic cavity, and at least part of the wall of the front acoustic cavity and / or the rear acoustic cavity is formed by the reinforcement part.

[0057] like Figure 1 As shown, a front sound cavity is formed between the first shell 10 and the sound-emitting monomer 20, and the front sound cavity has a sound outlet. The sound outlet is used to radiate sound waves outward. The front sound cavity can adjust the mid- and high-frequency effects of the sound-emitting device. A rear sound cavity is formed between the second shell 40 and the sound-emitting monomer 20. The rear sound cavity can adjust the low-frequency effect of the sound-emitting device. In this embodiment, at least part of the wall of the front sound cavity (e.g., the top wall 11 and the first side wall) or the wall of the rear sound cavity (e.g., the bottom wall 41 and the second side wall) is formed by a reinforcement portion; or at least part of the wall of the front sound cavity (e.g., the top wall 11 and the first side wall) and the wall of the rear sound cavity (e.g., the bottom wall 41 and the second side wall) are formed by a reinforcement portion. Since the thickness of the reinforcement portion is small, the volume of the front sound cavity and / or the rear sound cavity can be effectively increased, thereby improving the sound effect of the sound-emitting device.

[0058] In a specific embodiment of the present invention, the entire shell is composed of the reinforcement part.

[0059] In other words, in this embodiment, the first shell 10 and / or the second shell 40 are all made of a polyamide composite material, which includes polyamide and carbon fiber mixed together, the thickness of the reinforcement is ≤0.3 mm, the mass ratio of the carbon fiber to the polyamide is 0.42-1, and the density of the reinforcement is 1.2 g / cm 3 -1.45g / cm 3 , the bending modulus of the reinforcement part is 20GPa-40GPa. As mentioned above, the shell has the characteristics of high modulus, high strength, light weight and good thermal conductivity. For example, the first shell 10 is entirely made of polyamide composite material by integral injection molding, and part of the structure of the second shell 40 is integrally formed by polyamide composite material by integral injection molding; or, part of the structure of the first shell 10 is integrally formed by polyamide composite material by integral injection molding, and the second shell 40 is entirely made of polyamide composite material by integral injection molding; or, both the first shell 10 and the second shell 40 are entirely made of polyamide composite material by integral injection molding.

[0060] In a specific embodiment of the present invention, the shell further includes a base portion, and the base portion and the reinforcement portion are integrally injection molded.

[0061] Specifically, if Figure 1 As shown, for the first shell 10, the reinforcement portion is located at the top wall 11, and the first side wall includes the base portion; or the reinforcement portion is located at the first side wall, and the top wall 11 includes the base portion. For the second shell 40, the reinforcement portion is located at the bottom wall 41. The second side wall includes the base portion; or the reinforcement portion is located at the second side wall, and the top wall 41 includes the base portion. During injection molding, for example, the base portion is formed in one shot, and the reinforcement portion is formed on the base portion in the second shot. After curing, the base portion and the reinforcement portion are connected together. In this embodiment, the base portion and the reinforcement portion can be processed into a set shape according to actual needs to meet the sound requirements of different sound-emitting devices. In this setting, different parts of the first shell 10 and / or the second shell 40 can be made of different materials according to different functions, and 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.

[0062] In a specific embodiment of the present invention, the base 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.

[0063] When preparing the base part, 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.

[0064] In a specific embodiment of the present invention, the base 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.

[0065] 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 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 1, the density of the formed polyamide composite material is large, and the lightweight housing requirement is not met. In this embodiment, the mass ratio of the fiber material to the resin material is 0.25-1, and within the range, the polyamide composite material has both high strength and modulus and the mass of the formed housing 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 formed housing is light.

[0066] In a specific embodiment of the present invention, the bending strength of the reinforcement portion is 200MPa-450MPa;

[0067] And / or, the thermal deformation temperature of the reinforcement portion is ≥250°C.

[0068] 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 less than 200MPa, the shell is prone to deformation or even fracture when impacted; when the bending strength is greater than 450MPa, the shell has poor fluidity during injection molding and is difficult to process. In this embodiment, the bending strength of the shell is 200MPa-450MPa. 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 200MPa, 250MPa, 300MPa, 350MPa, 400MPa, 450MPa, etc. The above values ​​all make the shell have excellent impact resistance and low processing difficulty, and the product yield is high.

[0069] In a specific embodiment of the present invention, the thermal deformation temperature of the shell is ≥250°C.

[0070] 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 conditions. In this embodiment, the heat deformation temperature of the shell is ≥250°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 250°C, 260°C, 270°C, 300°C, 320°C, 330°C, 350°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.

[0071] In a specific embodiment of the present invention, the bending strength of the shell is 200MPa-450MPa, and the thermal deformation temperature of the shell is ≥250°C. In other words, the performance of the shell meets the above two conditions. This significantly improves the shell's anti-deformation ability and high temperature resistance and reduces processing difficulty.

[0072] 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.

[0073] like Figure 1 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 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. Side wall edges 15 are provided on the edges of the first shell 10 and the second shell 40. The side wall edges 15 of the first shell 10 and the second shell 40 are connected together by ultrasonic welding or glue.

[0074] The sound-generating device has the characteristics of high structural strength, good high temperature resistance and good sound-generating effect.

[0075] In a specific embodiment of the present invention, the sound-emitting device also includes a sound-emitting unit arranged in the shell, and the sound-emitting unit includes a vibration system. Along the vibration direction of the vibration system, at least a part of the shell opposite to the sound-emitting unit is composed of the reinforcement part.

[0076] like Figure 1 As shown, the interior of the housing forms a front sound cavity 111 and a rear sound cavity 121. The sound-emitting unit is located between the front sound cavity 111 and the rear sound cavity 121. The front sound cavity 111 has a sound outlet. The sound outlet is used to radiate sound waves outward. The sound-emitting unit 20 includes a vibration system. The vibration direction of the vibration system is as shown in FIG. Figure 1 As shown by the arrow in the middle. Along the vibration direction of the vibration system, the shell that is at least partially opposite to the sound-emitting unit is, for example, at least a portion of the top wall 11 or at least a portion of the bottom wall 41; it can also be at least a portion of the top wall 11 and at least a portion of the bottom wall 41. When the reinforcement portion is located on the top wall 11, since the thickness of the reinforcement portion is relatively thin, for example, the thickness is ≤0.3mm, this makes the size of the front sound cavity 111 along the vibration direction larger under the same shell size, thereby allowing the vibration amplitude of the vibration system of the sound-emitting unit to be larger, thereby making the sound effect of the sound-emitting device better. When the reinforcement portion is located on the bottom wall 41, the size of the rear sound cavity 121 in the vibration direction is larger, so that the low-frequency effect of the sound-emitting device is better. It is also possible that the reinforcement portion is located on both the top wall 11 and the bottom wall 41, and the sound-emitting device can have both of the above advantages, which makes the sound effect of the sound-emitting device better.

[0077] 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, a vehicle, etc.

[0078] 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.

[0079] Comparative Example 1

[0080] The shell is formed by insert injection molding using steel sheets and PPA materials, the insert is located on the top wall 11, and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0081] Example 1

[0082] A shell is formed by injection molding using 70wt% PPA material and 30wt% carbon fiber, with the reinforcement portion located on the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0083] Example 2

[0084] A shell is formed by injection molding using 65wt% PPA material and 35wt% carbon fiber, with the reinforcement portion located on the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0085] Example 3

[0086] A shell is formed by injection molding using 60wt% PPA material and 40wt% carbon fiber, with the reinforcement portion located on the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0087] Example 4

[0088] A shell is formed by injection molding using 55wt% PPA material and 45wt% carbon fiber, with the reinforcement portion located on the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0089] Example 5

[0090] A shell is formed by injection molding using 50wt% PPA material and 50wt% carbon fiber, with the reinforcement portion located on the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0091] Example 6

[0092] A shell is formed by injection molding using 65wt% PA4T and 35wt% carbon fiber, with the reinforcement portion located at the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0093] Example 7

[0094] A shell is formed by injection molding using 60wt% PA5T and 40wt% carbon fiber, with the reinforcement portion located at the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0095] Example 8

[0096] A shell is formed by injection molding using 55wt% PA6T and 45wt% carbon fiber, with the reinforcement portion located at the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0097] Example 9

[0098] A shell is formed by injection molding using 60wt% PA9T and 40wt% carbon fiber, with the reinforcement portion located at the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0099] Example 10

[0100] A shell is formed by injection molding using 65wt% PA10T and 35wt% carbon fiber, with the reinforcement portion located at the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0101] Embodiment 11

[0102] A shell is formed by injection molding using 55wt% PA12T and 45wt% carbon fiber, with the reinforcement portion located on the top wall 11 , and the obtained shell is assembled with the sound-generating monomer 20 to obtain a sound-generating device.

[0103] It should be noted that the outer dimensions of the shells in the comparative example and the examples are consistent. For the convenience of comparison, the raw material proportions of comparative example 1 and examples 1-11 are shown in Table 1.

[0104] Table 1 - Raw material ratios of the shells of the embodiments and comparative examples

[0105]

[0106] The steel sheet of comparative example 1 and the shells of embodiments 1-11 were tested for heat deformation temperature, density, bending modulus and bending strength, and the test results are shown in Table 2 and Table 3.

[0107] The test conditions and standards are as follows:

[0108] (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.

[0109] (2) 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 polyamide composites.

[0110] (3) 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.

[0111] Table 2 - Performance test comparison table of the shell of the embodiment and the steel sheet of the comparative example

[0112]

[0113]

[0114] As can be seen from Table 2, the heat deformation temperature of the shells of Examples 1-11 is ≥270°C. The bending strength of the shells of Examples 1-11 is between 200MPa and 450MPa. The bending strength of the steel sheet of Comparative Example 1 is 500MPa. The bending modulus of the shells of Examples 1-11 is between 20GPa and 40GPa. The bending modulus of the steel sheet of Comparative Example 1 is 195GPa.

[0115] In addition, the density of the shells of Examples 1-11 is all 1.2 g / cm 3 -1.45g / cm 3 The density of the steel sheets in Comparative Example 1 is ≥7.93 g / cm 3 , this density does not meet the requirement of lightweight shell.

[0116] It can be seen that the shell of Example 1-11 is made of a polyamide composite material by injection molding. The polyamide composite material includes carbon fiber and polyamide mixed together. The mass ratio of the carbon fiber to the polyamide is 0.42-1. The density of the reinforcement part is 1.2 g / cm 3 -1.45g / cm 3 The bending modulus of the reinforcement part is 20GPa-40GPa, and the thickness of the reinforcement part is ≤0.3mm, which makes the thermal deformation temperature, bending modulus, and bending strength of the shell of Examples 1-11 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 Examples 1-11 is relatively small, meeting the lightweight requirements of the shell.

[0117] The shell of comparative example 1 is made of injection-molded steel sheet, but the density of the steel sheet is too high and does not meet the requirement of lightweight shell.

[0118] In addition to the above tests, the process performance of the shells of Examples 1-11 and the shell of Comparative Example 1 was also tested, see Table 3 for details.

[0119] Table 3 - Comparison of process performance tests of the shells of the embodiment and the comparative example

[0120]

[0121]

[0122] As can be seen from Table 3, the yield of the injection molding process of the shells of Examples 1-11 is relatively high, reaching 100%. However, the shell of Comparative Example 1 is formed by injecting a steel sheet using an insert injection molding process. Due to the different shrinkage rates of the PPA material and the steel sheet, the shell is easily deformed, and cracks are easily formed between the PPA and the steel sheet. Therefore, the product yield is low, only 75%.

[0123] In summary, the shell of Comparative Example 1 is formed by insert injection molding of steel sheets. The density of the steel sheet is too high, resulting in a large overall mass of the shell, which does not meet the requirements for lightweight shell. In addition, in this process, the shrinkage rates of the PPA material and the steel sheet are different, which can easily cause deformation of the shell, and cracks are easily formed between the PPA and the steel sheet, resulting in a low product yield, which cannot meet the requirements for sealing performance.

[0124] The shell of Example 1-11 is formed by injection molding polyamide and carbon fiber materials. The mass ratio of carbon fiber to polyamide is 0.42-1. Carbon fiber can significantly improve the strength and modulus of polyamide composite materials. In addition, since polyamide has the characteristic of low density, the density of the shell is 1.2g / cm 3 -1.45g / cm 3range, so that a lightweight design of the shell can be achieved. The heat deformation temperature of polyamide is ≥250°C, which can reduce the strength drop of the shell during high-temperature operation and has strong structural stability. In addition, the bending modulus of the shell is in the range of 20GPa-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 200MPa-450MPa, and the shell is not easy to deform when impacted, and it is not easy to crack between the steel sheet and the injection molding material. In addition, the shell of Examples 1-11 does not need to be provided with a steel sheet, the processing technology is simple, and the product yield is high.

[0125] 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.

[0126] 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 shell includes a reinforcement part, the thickness of the reinforcement part is ≤0.3mm, the reinforcement part is formed by injection molding of a polyamide composite material composed of carbon fiber and polyamide, wherein in the reinforcement part, the mass ratio of the carbon fiber to the polyamide is 0.42-1, and the density of the reinforcement part is 1.2g / cm 3 -1.45g / cm 3 , the bending modulus of the reinforcement portion is 20GPa-40GPa.

2. The housing of the sound-generating device according to claim 1, characterized in that: The polyamide includes semi-aromatic polyamide, and the semi-aromatic polyamide includes at least one of PPA, PA46, PA4T, PA5T, PA6T, PA9T, PA10T, and PA12T.

3. The housing of the sound-generating device according to claim 1, characterized in that: The carbon content of the carbon fiber is 92%-99.99%, and / or the graphitization degree R value of the carbon fiber is 0.8-1.05, and / or the length of the carbon fiber is 0.1mm-1mm, and / or the orientation angle of the graphite crystallites of the carbon fiber is ≤25°.

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

5. The housing of the sound-generating device according to claim 1, characterized in that: An accommodating cavity is disposed inside the housing, and at least a portion of a wall of the accommodating cavity is formed by the reinforcement portion.

6. The housing of the sound-generating device according to claim 5, characterized in that: The accommodating cavity comprises a front acoustic cavity and a rear acoustic cavity, and at least a part of the wall of the front acoustic cavity and / or the rear acoustic cavity is formed by the reinforcement part.

7. The housing of the sound-generating device according to claim 1, characterized in that: The entirety of the shell is composed of the reinforcement part.

8. The housing of the sound-generating device according to claim 1, characterized in that: The shell further comprises a base portion, and the base portion and the reinforcement portion are integrally injection-molded.

9. The housing of the sound-generating device according to claim 8, characterized in that: The base 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 base part also includes a fiber material, and 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.

11. The housing of the sound-generating device according to claim 1, characterized in that: The bending strength of the reinforcement portion is 200MPa-450MPa; And / or, the thermal deformation temperature of the reinforcement portion is ≥250°C.

12. A sound-generating device, characterized in that: A housing comprising the sound emitting device according to any one of claims 1 to 11.

13. The sound generating device according to claim 12, characterized in that: The sound-generating device further comprises a sound-generating unit disposed in the shell, the sound-generating unit comprises a vibration system, and along the vibration direction of the vibration system, at least a portion of the shell opposite to the sound-generating unit is composed of the reinforcement portion.

14. An electronic device, characterized in that: Comprising the sound-generating device as claimed in claim 13.

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