Integrated injection molding loudspeaker, manufacturing method and electronic equipment

Abstract

The invention provides an integrated injection molding loudspeaker, a manufacturing method and electronic equipment, the integrated injection molding loudspeaker comprises a first sound cavity support, a second sound cavity support, a magnetic circuit assembly, a vibration assembly and a flexible circuit board, the magnetic circuit assembly is wrapped by plastic through an in-mold injection molding technology, and the magnetic circuit assembly and the first sound cavity support are integrated; the vibration assembly is assembled on the second sound cavity support in a gluing mode. The flexible circuit board is welded on the vibration assembly so as to realize circuit conduction; the first sound cavity support and the second sound cavity support are fixedly connected in an ultrasonic welding mode. According to the invention, the magnetic circuit assembly is wrapped by the plastic through the in-mold injection molding process and is integrated with the first sound cavity support, so that the magnetic circuit assembly and the first sound cavity support form a gapless rigid connection structure, the key part does not need to be sealed by a gluing process, and the core pain point that the use amount of glue is difficult to control is thoroughly avoided.

Description

Technical Field

[0001] This invention relates to the field of acoustic technology, and more specifically to an integrally injection-molded loudspeaker. Background Technology

[0002] Loudspeakers are commonly used electroacoustic transducers that convert electrical energy into sound energy. For example, Chinese patent document CN103338424A discloses a miniature loudspeaker.

[0003] To accommodate various installation space height restrictions, it adopts an external magnetic frame (equivalent to the U-shaped iron of the present invention) design to save installation height. In this solution, the magnetic frame and the bracket are sealed by a glue application process. The glue seeps in along the gap between the magnetic frame and the bracket (equivalent to the first acoustic cavity bracket of the present invention). If too much glue is used or before the glue cures, the glue can easily seep into the vibration component, damaging the internal components of the vibration component and ultimately causing product defects. If the glue is insufficient, it will lead to poor sealing. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to propose an integrated injection-molded loudspeaker and its manufacturing method, as well as an electronic device, to solve the problems mentioned in the background section above.

[0005] This invention is achieved through the following technical solution: An integrated injection-molded loudspeaker includes a first acoustic cavity support, a second acoustic cavity support, a magnetic circuit assembly, a vibration assembly, and a flexible circuit board. The magnetic circuit assembly is encapsulated in plastic through in-mold injection molding and integrated with the first acoustic cavity support. The vibration assembly is glued to the second acoustic cavity support. The flexible circuit board is soldered to the vibration assembly to achieve circuit conduction. The first acoustic cavity support and the second acoustic cavity support are fixedly connected by ultrasonic welding.

[0006] Furthermore, the first acoustic cavity support and the second acoustic cavity support are closed to form an installation space and a hollow space, and the vibration component and the flexible circuit board are both disposed in the installation space.

[0007] Furthermore, the first acoustic cavity support has a through hole communicating with the hollow space, and a damping mesh is attached to the opening of the through hole.

[0008] Furthermore, the magnetic circuit assembly includes a U-shaped iron, a magnet, and a magnetic core, which are fixedly connected and assembled by adhesive bonding to form the magnetic circuit assembly.

[0009] Furthermore, the vibration assembly includes a base frame, a diaphragm, and a voice coil. The base frame, diaphragm, and voice coil are fixedly connected and assembled to form the vibration assembly by adhesive bonding. The flexible circuit board is soldered to the base frame.

[0010] Furthermore, the U-shaped iron has folded portions extending toward the second acoustic cavity support around its perimeter. The magnet and the magnetic core are sequentially and centrally glued to the lower end of the U-shaped iron. The diaphragm is glued to the lower end of the base frame. The voice coil is arranged in the hollow part of the base frame. A first clearance groove is provided between the base frame and the voice coil. The folded portions are embedded in the first clearance groove. A second clearance groove is provided between the U-shaped iron and the magnet and the magnetic core. The upper end of the voice coil is embedded in the second clearance groove.

[0011] Furthermore, a sound amplification space is provided between the lower end of the diaphragm and the second acoustic cavity support, and the second acoustic cavity support is provided with an oblique sound outlet hole that connects to the outside and the sound amplification space.

[0012] Furthermore, the diaphragm is provided with an annular concave portion.

[0013] On the other hand, the present invention provides a method for manufacturing an integrated injection-molded loudspeaker as described in any of the preceding claims, comprising the following steps: S1: The U-shaped iron, magnet and magnetic core are fixedly connected by adhesive to form a magnetic circuit assembly; S2: Place the magnetic circuit assembly obtained in step S1 into the injection mold, and inject plastic material into the mold using in-mold injection molding process. After injection molding, the magnetic circuit assembly is wrapped in plastic and integrated with the first sound cavity support to obtain the first sound cavity support with the magnetic circuit assembly. S3: The base frame, diaphragm and voice coil are fixedly connected by adhesive to form a vibration assembly, and then the vibration assembly is assembled to the second acoustic cavity support by adhesive. S4: Weld the flexible circuit board to the base frame of the vibration component described in step S3 to achieve circuit conduction; S5: The first acoustic cavity support with magnetic circuit components obtained in step S2 is fixedly connected to the second acoustic cavity support with vibration components and flexible circuit boards obtained in step S4 by ultrasonic welding.

[0014] On the other hand, the present invention provides an electronic device including an integrally injection-molded speaker as described in any of the preceding claims.

[0015] The beneficial effects of this invention are as follows: The integrated injection-molded loudspeaker includes a first acoustic cavity support, a second acoustic cavity support, a magnetic circuit assembly, a vibration assembly, and a flexible circuit board. The magnetic circuit assembly is encapsulated in plastic through in-mold injection molding and integrated with the first acoustic cavity support. The vibration assembly is glued to the second acoustic cavity support. The flexible circuit board is soldered to the vibration assembly to achieve circuit conductivity. The first acoustic cavity support and the second acoustic cavity support are fixedly connected by ultrasonic welding. This invention encapsulates the magnetic circuit assembly in plastic through in-mold injection molding and integrates it with the first acoustic cavity support, forming a gapless rigid connection structure between the magnetic circuit assembly and the first acoustic cavity support. This eliminates the need for sealing with glue in this critical area, completely avoiding the core pain point of difficult-to-control glue usage. Attached Figure Description

[0016] Figure 1 This is a perspective view of the integrated injection-molded loudspeaker of the present invention.

[0017] Figure 2 This is an exploded view of the integrated injection-molded loudspeaker of the present invention.

[0018] Figure 3 This is another exploded view of the integrated injection-molded speaker of the present invention.

[0019] Figure 4 for Figure 1 Sectional view at point AA along the middle.

[0020] Figure 5 for Figure 1 Sectional view at the middle edge BB.

[0021] The above figures include the following reference numerals: 1. First acoustic cavity support; 11. Through hole; 2. Second acoustic cavity support; 3. Magnetic circuit assembly; 31. U-shaped iron; 311. Folding part; 312. Arc-shaped support; 32. Magnet; 33. Magnetic core; 34. Second clearance groove; 4. Vibration assembly; 41. Base frame; 42. Diaphragm; 421. Annular concave part; 43. Voice coil; 44. First clearance groove; 5. Flexible circuit board; 6. Damping mesh; A. Installation space; B. Hollowed-out space; C. Amplification space; D. Angled sound hole. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of aiding understanding the present invention, but does not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0023] Reference Figures 1 to 5 As shown, the integrated injection-molded loudspeaker includes a first acoustic cavity support 1, a second acoustic cavity support 2, a magnetic circuit assembly 3, a vibration assembly 4, and a flexible circuit board 5. The magnetic circuit assembly 3 is encapsulated in plastic through in-mold injection molding and is integrated with the first acoustic cavity support 1. The vibration assembly 4 is assembled to the second acoustic cavity support 2 by adhesive bonding. The flexible circuit board 5 is welded to the vibration assembly 4 to achieve circuit conduction. The first acoustic cavity support 1 and the second acoustic cavity support 2 are fixedly connected by ultrasonic welding.

[0024] The present invention encapsulates the magnetic circuit component 3 in plastic through in-mold injection molding and integrates it with the first sound cavity support 1, so that the magnetic circuit component 3 and the first sound cavity support 1 form a rigid connection structure without gaps, eliminating the need for glue and avoiding the core pain point of difficulty in controlling the amount of glue used.

[0025] The first acoustic cavity support 1 and the second acoustic cavity support 2 of the present invention are fixedly connected by ultrasonic welding. Ultrasonic welding can form a uniform and firm sealing structure without the need for glue, thus avoiding the core pain point of difficulty in controlling the amount of glue used.

[0026] The present invention applies glue to the back end of the vibration component 4 or applies glue to a pre-set glue application area on the inner side of the second acoustic cavity support 2. Since the glue application area is always far away from the internal core structure of the vibration component 4, and the vibration component 4 is embedded in the inner side of the second acoustic cavity support 2, the glue will not penetrate upward into the internal core structure of the vibration component 4 before curing by the adhesive fixing method of overlapping the upper and lower parts.

[0027] During the assembly process, the magnetic circuit component 3 and the first acoustic cavity support 1 are first integrated into one assembly. The vibration component 4 and the second acoustic cavity support 2 are then bonded together through a preset adhesive application area. Finally, the first acoustic cavity support 1 and the second acoustic cavity support 2 are assembled together. This segmented assembly method allows for direct observation of the internal core structure of the vibration component 4 before assembly to check for any accidental glue penetration, facilitating the accurate early removal of defective products and effectively improving the overall product yield.

[0028] Furthermore, the first acoustic cavity support 1 and the second acoustic cavity support 2 close to form an installation space A and a hollow space B, and the vibration component 4 and the flexible circuit board 5 are both disposed in the installation space A. The hollow space B is a functional expansion area independent of the installation space A, and can be flexibly configured with different functional components according to the application scenario and performance requirements of the speaker. Specific examples are as follows: Firstly, an auxiliary magnet can be set in the hollow space B to enhance the magnetic field density in the installation space A, thereby increasing the driving force of the voice coil 43 in the speaker vibration assembly 4, and especially enhancing the fullness and depth of the low-frequency response. Secondly, small auxiliary electronic components, such as miniature filter capacitors and audio equalizer chips, can be fixed in the hollow space B to optimize audio signal transmission and reduce distortion. Thirdly, the heat generated by the magnetic circuit component 3 and vibration component 4 in the installation space A can be conducted to the hollow space B through the thin wall, increasing the heat dissipation area. Combined with the air flow in the hollow space B, passive heat dissipation is achieved, avoiding problems such as magnetic force attenuation and aging of the insulation layer of the voice coil 43 caused by overheating.

[0029] The first acoustic cavity support 1 has a through hole 11 communicating with the hollow space B, and a damping mesh 6 is attached to the opening of the through hole 11. The damping mesh 6 is made of sound-absorbing material. The damping mesh 6 can absorb some high-frequency noise and reflected sound waves, reduce the repeated reflection of sound waves between the installation space A and the hollow space B, and suppress the generation of standing waves. At the same time, the sound transmission characteristics of the damping mesh 6 do not hinder the normal propagation of sound waves, but only filter noise, making the output sound quality purer and the frequency response curve smoother.

[0030] Furthermore, the magnetic circuit assembly 3 includes a U-shaped iron 31, a magnet 32, and a magnetic core 33, which are fixedly connected and assembled by adhesive bonding to form the magnetic circuit assembly 3.

[0031] Specifically, magnet 32 ​​is centrally attached to the lower end face of the central region of U-iron 31. The outline of magnetic core 33 from a top view is the same as that of magnet 32, and magnet 32 ​​is stacked at the lower end of magnetic core 33. Magnet 32 ​​is used to provide a continuous, stable, and strong static magnetic field. U-iron 31 has a groove-shaped structure that can accommodate and fix magnet 32 ​​and magnetic core 33, forming a rigid whole with them by adhesive bonding. Magnetic core 33, as a component with high magnetic permeability, works with magnet 32 ​​and U-iron to form a closed magnetic circuit. Its core function is to gather and conduct the static magnetic field generated by magnet 32. The magnetic field provided by magnet 32 ​​is conducted downward through magnetic core 33, and then transmitted to U-iron 31 through the annular magnetic gap on the outside of magnetic core 33, ultimately forming a closed magnetic circuit.

[0032] The U-shaped iron 31 has outwardly extending arc-shaped support ears 312 around its perimeter. During the process of the magnetic circuit assembly 3 being encased in plastic through in-mold injection molding, the cavity of the injection mold completely covers the arc-shaped support ears 312. The first sound cavity support 1 includes the perimeter of the arc-shaped support ears 312 to prevent the magnetic circuit assembly 3 from separating from the first sound cavity support 1 due to factors such as vibration and temperature changes after in-mold injection molding.

[0033] Furthermore, the vibration assembly 4 includes a base frame 41, a diaphragm 42, and a voice coil 43. The base frame 41, the diaphragm 42, and the voice coil 43 are fixedly connected and assembled by adhesive to form the vibration assembly 4. The flexible circuit board 5 is welded to the base frame 41.

[0034] Specifically, the base frame 41 serves as the welding base for the flexible circuit board 5 (FPC). The flexible circuit board 5 is fixed to the base frame 41 by welding and realizes circuit conduction, providing a stable current input channel for the voice coil 43. The diaphragm 42 reciprocates under the electromagnetic driving force of the voice coil 43, pushing the surrounding air to form compression and sparse waves, which are then converted into audible sound. After the voice coil 43 is connected to the external audio current through the flexible circuit board 5, it will generate an electromagnetic force in the annular magnetic gap of the magnetic circuit assembly 3. This electromagnetic force drives the voice coil 43 to perform axial reciprocating motion, which in turn drives the diaphragm 42 to vibrate synchronously.

[0035] Furthermore, the U-shaped iron 31 is provided with folded portions 311 extending toward the second acoustic cavity support 2 around its periphery. The magnet 32 ​​and the magnetic core 33 are sequentially and centrally glued to the lower end of the U-shaped iron 31. The diaphragm 42 is glued to the lower end of the base frame 41. The voice coil 43 is arranged in the hollow part of the base frame 41. A first clearance groove 44 is provided between the base frame 41 and the voice coil 43. The folded portions 311 are embedded in the first clearance groove 44. A second clearance groove 34 is provided between the U-shaped iron 31 and the magnet 32 ​​and the magnetic core 33. The upper end of the voice coil 43 is embedded in the second clearance groove 34.

[0036] In the above embodiments, by embedding the folding part 311 into the first clearance groove 44 and the upper end of the voice coil 43 into the second clearance groove 34, the longitudinal spatial overlap of the magnetic circuit assembly 3 and the vibration assembly 4 can be achieved, so that the overall height of the speaker of the present invention is compressed to the maximum extent, adapting to the height restrictions of various electronic devices on the installation space A, and conforming to the development trend of thin products.

[0037] In the above embodiment, the upper end of the voice coil 43 is embedded in the second clearance groove 34 and does not contact the U-shaped iron 31 or the magnet 32, so that the voice coil 43 is closer to the core magnetic field region, shortening the magnetic circuit path, reducing magnetic leakage, and significantly increasing the magnetic field density in the magnetic gap. This makes the voice coil 43 more uniformly stressed and stronger when energized, achieving a larger diaphragm 42 amplitude under the same current input, and improving the output volume and low-frequency extension. At the same time, the diaphragm 42 does not contact the folded part 311, ensuring that the diaphragm 42 vibrates without mechanical obstruction, and can fully utilize its own vibration characteristics. Combined with the embedded structure, it suppresses split vibration, reduces harmonic distortion, makes the frequency response curve smoother, and the sound quality purer.

[0038] A sound amplification space C is provided between the lower end of the diaphragm 42 and the second acoustic cavity support 2, and the second acoustic cavity support 2 is provided with an oblique sound outlet D that connects to the outside and the sound amplification space C.

[0039] In the above embodiment, the amplification space C between the lower end of the diaphragm 42 and the second acoustic cavity support 2 provides sufficient space for the diffusion and resonance of the sound waves generated by the vibration of the diaphragm 42, avoiding the direct reflection of the sound waves to the surface of the diaphragm 42 at close range and causing interference, effectively suppressing harmonic distortion; at the same time, the oblique sound hole D adopts an inclined angle design, so that the sound waves radiate outward in a non-vertical direction, which not only widens the sound coverage range, but also enhances the auditory stereo effect.

[0040] Furthermore, the diaphragm 42 is provided with an annular concave portion 421. The stress generated when the diaphragm 42 vibrates will be evenly distributed along the arc-shaped contour of the annular concave portion 421, avoiding stress concentration at the edge or center of the diaphragm 42, which can effectively extend the service life of the diaphragm 42.

[0041] On the other hand, the present invention provides a method for manufacturing an integrated injection-molded loudspeaker as described in any of the preceding claims, comprising the following steps: S1: The U-shaped iron 31, the magnet 32 ​​and the magnetic core 33 are fixedly connected by adhesive to form a magnetic circuit assembly 3; S2: Place the magnetic circuit component 3 obtained in step S1 into the injection mold, and inject plastic material into the mold using in-mold injection molding process. After injection molding, the U-iron 31 of the magnetic circuit component 3 is wrapped in plastic and integrated with the first sound cavity support 1 to obtain the first sound cavity support 1 with magnetic circuit component 3. S3: The base frame 41, diaphragm 42 and voice coil 43 are fixedly connected by adhesive to form a vibration assembly 4, and then the vibration assembly 4 is assembled to the second acoustic cavity support 2 by adhesive. S4: Weld the flexible circuit board 5 onto the base 41 of the vibration component 4 described in step S3 to achieve circuit conduction; S5: The first acoustic cavity support 1 with magnetic circuit component 3 obtained in step S2 is fixedly connected to the second acoustic cavity support 2 with vibration component 4 and flexible circuit board 5 obtained in step S4 by ultrasonic welding.

[0042] In steps S1 and S3, the adhesive used for bonding can be high-temperature resistant epoxy AB glue; in step S2, the first acoustic cavity support 1 can be made of plastics with excellent melt flowability such as ABS or PC. The ultrasonic welding process in step S4 is existing technology and will not be described in detail here.

[0043] The manufacturing method of the integrated injection-molded loudspeaker of the present invention further includes the following steps: S6: Apply glue to seal the slot of the flexible circuit board 5. Since the slot is far away from the magnetic circuit assembly 3 and the vibration assembly 4, even if too much glue is applied, it will not overflow to key components such as the diaphragm 42, voice coil 43, and magnetic core 33.

[0044] S7: The first acoustic cavity support 1 has a through hole 11 that communicates with the hollow space B, and a damping mesh 6 is attached to the opening of the through hole 11.

[0045] On the other hand, the present invention provides an electronic device, which includes a housing and an integrated injection-molded speaker as described in any of the above technical solutions. The integrated injection-molded speaker is detachably or non-detachably mounted in a preset mounting position inside the housing through a preset mounting structure, and the flexible circuit board 5 of the integrated injection-molded speaker is electrically connected to the main board of the electronic device to realize the audio playback, voice interaction or prompt tone output functions of the electronic device; wherein, the electronic device is selected from at least one of mobile phones, tablet computers, laptops, smartwatches, smart bracelets, smart headphones, smart speakers, portable audio players, vehicle terminals, smart home devices, and wearable electronic devices.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A one-piece injection-molded loudspeaker, characterized in that: The device includes a first acoustic cavity support (1), a second acoustic cavity support (2), a magnetic circuit assembly (3), a vibration assembly (4), and a flexible circuit board (5). The magnetic circuit assembly (3) is encapsulated in plastic by in-mold injection molding and integrated with the first acoustic cavity support (1). The vibration assembly (4) is assembled to the second acoustic cavity support (2) by adhesive bonding. The flexible circuit board (5) is welded to the vibration assembly (4) to achieve circuit conduction. The first acoustic cavity support (1) and the second acoustic cavity support (2) are fixedly connected by ultrasonic welding.

2. The integrated injection-molded loudspeaker according to claim 1, characterized in that: The first acoustic cavity support (1) and the second acoustic cavity support (2) close to form an installation space (A) and a hollow space (B), and the vibration component (4) and the flexible circuit board (5) are both located in the installation space (A).

3. The integrated injection-molded loudspeaker according to claim 2, characterized in that: The first acoustic cavity support (1) has a through hole (11) communicating with the hollow space (B), and a damping mesh (6) is pasted at the opening of the through hole (11).

4. The integrated injection-molded loudspeaker according to claim 1, characterized in that: The magnetic circuit assembly (3) includes a U-shaped iron (31), a magnet (32) and a magnetic core (33), which are fixedly connected and assembled by adhesive bonding to form the magnetic circuit assembly (3).

5. The integrated injection-molded loudspeaker according to claim 4, characterized in that: The vibration assembly (4) includes a base frame (41), a diaphragm (42) and a voice coil (43). The base frame (41), the diaphragm (42) and the voice coil (43) are fixedly connected and assembled by adhesive to form the vibration assembly (4). The flexible circuit board (5) is welded to the base frame (41).

6. The integrated injection-molded loudspeaker according to claim 5, characterized in that: The U-shaped iron (31) has folded portions (311) extending toward the second acoustic cavity support (2) around its perimeter. The magnet (32) and the magnetic core (33) are glued to the lower end of the U-shaped iron (31) in sequence. The diaphragm (42) is glued to the lower end of the base frame (41), the voice coil (43) is arranged in the hollow part of the base frame (41), a first clearance groove (44) is provided between the base frame (41) and the voice coil (43), and the folding part (311) is embedded in the first clearance groove (44); A second clearance groove (34) is provided between the U-iron (31) and the magnet (32) and the magnetic core (33), and the upper end of the voice coil (43) is embedded in the second clearance groove (34).

7. The integrated injection-molded loudspeaker according to claim 8, characterized in that: A sound amplification space (C) is provided between the lower end of the diaphragm (42) and the second acoustic cavity support (2), and the second acoustic cavity support (2) is provided with an oblique sound outlet (D) that connects the outside to the sound amplification space (C).

8. The integrated injection-molded loudspeaker according to claim 7, characterized in that: The diaphragm (42) is provided with an annular concave portion (421).

9. A method for manufacturing an integrated injection-molded loudspeaker as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1: The U-iron (31), magnet (32) and magnetic core (33) are fixedly connected by adhesive to form a magnetic circuit assembly (3). S2: Place the magnetic circuit component (3) obtained in step S1 into the injection mold, and inject plastic material into the mold using in-mold injection molding process. After injection molding, the magnetic circuit component (3) is wrapped in plastic and integrated with the first acoustic cavity support (1) to obtain the first acoustic cavity support (1) with the magnetic circuit component (3). S3: The base frame (41), diaphragm (42) and voice coil (43) are fixedly connected by adhesive to form a vibration assembly (4), and then the vibration assembly (4) is assembled to the second acoustic cavity support (2) by adhesive. S4: Weld the flexible circuit board (5) onto the base frame (41) of the vibration component (4) described in step S3 to achieve circuit conduction; S5: The first acoustic cavity support (1) with magnetic circuit assembly (3) obtained in step S2 is fixedly connected to the second acoustic cavity support (2) with vibration assembly (4) and flexible circuit board (5) obtained in step S4 by ultrasonic welding.

10. An electronic device, characterized in that, Including the integrally injection-molded loudspeaker as described in any one of claims 1 to 8.

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