A dual-unit reverse coaxial loudspeaker and a dual-unit reverse coaxial sound emitting method

Abstract

This invention relates to a dual-unit reverse coaxial loudspeaker and a dual-unit reverse coaxial sound generation method, comprising a frame body, two sets of sound generating units, and a sealed outer casing. The frame body is a one-piece molded structure, including a base column and mounting brackets at its upper and lower ends. The two sets of sound generating units are coaxially mounted with their sound-emitting ends facing each other in the receiving cavity of the mounting bracket, forming a reverse sound generation structure. The two mounting brackets, the base column, and the sealed outer casing form an annular side sound cavity. The receiving cavity is connected to the side sound cavity through a through hole on the mounting bracket. The sealed outer casing has a sound outlet. The sound emitted by the sound generating units enters the side sound cavity sequentially through the receiving cavity and the through hole and radiates outward from the sound outlet, forming a lateral sound generation path. This invention eliminates assembly errors and magnetic leakage through the one-piece molded frame, improving coaxiality and electroacoustic efficiency; the lateral sound generation path breaks through the traditional axial space limitations, which is beneficial for the thinning of the device; the design of the side sound cavity and exhaust port optimizes sound wave coupling and air pressure balance, significantly improving sound quality and acoustic performance.

Description

Technical Field

[0001] This invention relates to the technical field of loudspeakers, and more specifically, to a dual-unit reverse coaxial loudspeaker and a dual-unit reverse coaxial sound generation method. Background Technology

[0002] As portable electronic devices (such as TWS earphones, smartwatches, AR / VR glasses, etc.) rapidly develop towards miniaturization and thinner designs, higher demands are placed on the size control and acoustic performance of internal electroacoustic transducers (speakers). In order to achieve greater loudness and better sound quality within a limited micro-cavity, dual-unit loudspeaker and coaxial loudspeaker technologies have gradually become a hot research topic in the industry.

[0003] However, existing dual-unit reverse coaxial loudspeakers still have the following obvious shortcomings in practical applications: 1. Existing dual-unit loudspeakers are fixed and supported by two separate mounting brackets. This split assembly structure is prone to cumulative errors during assembly, making it difficult to ensure strict coaxiality of the two sound-generating units, resulting in uneven sound field distribution. In addition, the unavoidable assembly gap between the two separate mounting brackets not only increases the number of parts and assembly steps, but also prevents the two magnetic circuit systems from being tightly integrated, increasing magnetic leakage loss and significantly reducing the overall electroacoustic conversion efficiency.

[0004] 2. Traditional loudspeakers typically use an axial sound path, meaning that sound radiates directly from the front of the diaphragm along the axial direction. This sound emission method requires sufficient space for the sound outlet and front cavity on the front of the device (i.e., the front of the diaphragm) during the assembly of the final product, which severely encroaches on the space in the Z-axis (thickness) direction inside the device, making it unfavorable for the industrial design of ultra-thin electronic products.

[0005] In summary, there is an urgent need to provide a dual-unit reverse coaxial loudspeaker with an integrated basket structure and a reasonable acoustic path design. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a dual-unit reverse coaxial loudspeaker and a dual-unit reverse coaxial sound generation method, in view of the above-mentioned defects of the prior art.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows: On one hand, the present invention provides a dual-unit reverse coaxial loudspeaker, comprising a frame body, two sets of sound-generating units, and a sealed outer casing; the frame body is a one-piece molded structure, including a base column, the upper and lower ends of which are respectively provided with mounting brackets fixedly connected to the sealed outer casing; the two sets of sound-generating units are respectively mounted on the receiving cavities of the two mounting brackets; the two mounting brackets, the base column, and the sealed outer casing form an annular side sound cavity; the mounting brackets are provided with multiple through holes circumferentially; the receiving cavity is connected to the side sound cavity through the multiple through holes. The sealed outer cover is connected to the side sound cavity; the two sets of sound generating units are coaxial with the base column, and the sound generating ends of the two sets of sound generating units are arranged facing each other to form a reverse sound generating structure; the sound emitted by the sound generating unit enters the side sound cavity through the receiving cavity and the through hole in sequence, and finally radiates outward from the sound generating hole to form a lateral sound generating path; the upper and lower ends of the sealed outer cover are respectively provided with exhaust holes corresponding to the two sets of sound generating units, which are used to allow the sound waves on the back of the sound generating unit to be discharged to balance the air pressure.

[0008] The dual-unit reverse coaxial loudspeaker of the present invention includes a mounting bracket comprising an annular support plate extending laterally outward from the outer edge of the base column, and a first sidewall extending longitudinally outward from the outer edge of the annular support plate; the annular support plate, the first sidewall, and the base column mutually enclose each other to form the receiving cavity; and a plurality of through holes are circumferentially distributed on the annular support plate.

[0009] The present invention discloses a dual-unit reverse coaxial loudspeaker, wherein the sound-producing unit includes a magnet, a washer, and a horn arranged sequentially from the inside to the outside; the magnet, washer, and horn are coaxially arranged; the magnet provides a magnetic field, the washer guides the magnetic lines of force of the magnet to the gap of the voice coil of the horn, and the voice coil of the horn drives the diaphragm to vibrate and produce sound under the action of the electromagnetic field; the sound-producing end of the horn faces the washer, and the exhaust end of the horn faces the exhaust port.

[0010] The dual-unit reverse coaxial loudspeaker of the present invention has a limiting step on the first sidewall for positioning the outer edge of the loudspeaker.

[0011] The dual-unit reverse coaxial loudspeaker of the present invention comprises a base post having coaxially arranged recesses at both its upper and lower ends, which are connected to the corresponding receiving cavity; the magnet and the washer are fixed in the recesses, and the speaker is fixed on the mounting bracket; a gap is provided between the inner wall of the recess and the sound-generating unit, so that the sound inside the recess flows through the gap from the through hole to the side sound cavity.

[0012] The dual-unit reverse coaxial loudspeaker of the present invention includes a sealed outer casing comprising an annular second sidewall and two sealing plates respectively fixed at the upper and lower ends of the second sidewall for sealing the side acoustic chamber; the sound outlet is located on the second sidewall; and the two exhaust ports are respectively located on the two sealing plates.

[0013] The dual-unit reverse coaxial loudspeaker of the present invention has a tuning mesh provided at both of the two exhaust ports of the sealed outer cover, which is used to dampen and adjust the airflow and sound waves discharged from the exhaust ports to suppress airflow noise.

[0014] The dual-unit reverse coaxial loudspeaker of the present invention further includes a voice coil connection PCB on the outer surface of the sealed outer casing. The voice coil connection PCB is located on the second side wall and is used to realize the electrical conduction between the external audio electrical signal and the sound-generating unit.

[0015] The dual-unit reverse coaxial loudspeaker of the present invention has an opening end face of the cavity that is flush with or lower than the end face of the washer, so that the sound waves emitted by the speaker's sound-emitting end can enter the gap without obstruction.

[0016] On the other hand, the present invention provides a dual-unit reverse coaxial sound generation method, using a dual-unit reverse coaxial loudspeaker as described above, wherein the method includes the following steps: Step S1: Receive audio electrical signal and drive two sets of coaxially arranged sound generating units to vibrate in opposite directions at the same time, so that the sound generating ends of the two sets of sound generating units face each other to generate main sound waves, while the exhaust ends face away to generate back sound waves. In step S2, the main sound waves generated by the two sound-generating ends first radiate into their respective receiving cavities, and then flow outward from the inside to the annular side sound cavity formed by the two mounting frames, the base column and the sealed outer cover through multiple through holes arranged circumferentially on the mounting frame. Step S3: The main sound wave flowing into the side sound cavity undergoes acoustic coupling, and then radiates outward through the sound outlet on the sealed outer cover, forming a side sound path. In step S4, while the main sound wave radiates laterally, the back sound waves generated by the exhaust ends of the two sets of sound generating units are discharged outward through the exhaust holes at the upper and lower ends of the sealed outer cover, so as to balance the pressure difference between the inside and outside of the sound generating unit when it vibrates.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The frame body of this invention adopts a one-piece molding structure, with the base column and the mounting brackets at the top and bottom ends being integrated. This fundamentally eliminates the cumulative errors caused by separate assembly, ensuring that the two sets of sound-generating units can achieve strict coaxial installation, thereby guaranteeing the uniformity of the sound field distribution. Simultaneously, the integrated structure allows for the tight integration of the two magnetic circuit systems, effectively reducing magnetic leakage losses caused by the unavoidable assembly gaps between separate mounting brackets, allowing for full utilization of the energy of the entire magnetic circuit system, and significantly improving the overall electroacoustic conversion efficiency. Furthermore, the integrated design reduces the number of parts, simplifies the assembly process, and lowers manufacturing costs.

[0018] 2. This invention features a clever design that constructs an annular side acoustic cavity between the two mounting brackets, the base column, and the sealed outer casing. The main sound waves emitted from opposite directions first enter the receiving cavity, then flow evenly from the inside to the outside through circumferentially distributed through-holes into the side acoustic cavity, and finally radiate outwards through the sound outlet on the sealed outer casing, forming a lateral sound emission path. This lateral sound emission method is completely different from traditional axial sound emission. End products (such as TWS earphones, smartwatches, etc.) do not need to reserve space directly in front of the diaphragm, and can make full use of the side walls or edge gaps of the device to emit sound, thereby significantly reducing the requirements for product thickness and providing great freedom for the industrial design of ultra-thin electronic products. Moreover, this side sound emission path design effectively avoids direct collision and turbulent reflection of sound waves, reducing sound energy loss; at the same time, the annular side acoustic cavity, as an acoustic front cavity, plays a good role in acoustic impedance matching, allowing the two sets of sound waves to couple and superimpose in phase, significantly extending the low-frequency response, enhancing the low-frequency sound pressure, and making the output sound more robust and full. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 This is a schematic diagram of the structure of a dual-unit reverse coaxial loudspeaker in Embodiment 1 of the present invention.

[0020] Figure 2 yes Figure 1 An exploded three-dimensional view of a dual-unit reverse coaxial loudspeaker.

[0021] Figure 3 yes Figure 2 A schematic diagram of the structure of the middle basin frame body 11.

[0022] Figure 4 yes Figure 1 A top-view diagram of the sound emission state of a dual-unit reverse coaxial loudspeaker.

[0023] Figure 5 yes Figure 1 A three-dimensional cross-section of a dual-unit reverse coaxial loudspeaker.

[0024] Figure 6 yes Figure 5 A cross-sectional view of the sound emission state of a dual-unit reverse coaxial loudspeaker.

[0025] Figure 7 yes Figure 6 A schematic diagram of sound wave propagation in a dual-unit reverse coaxial loudspeaker.

[0026] Figure 8 This is a system performance simulation comparison table of a conventional forward dual-unit loudspeaker and a dual-unit reverse coaxial loudspeaker according to Embodiment 1 of the present invention. Detailed Implementation

[0027] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0030] Furthermore, the terms indicating orientation, such as "up, down, front, back, left, right, upper end, lower end, longitudinal," etc., are all based on the posture and position of the device or equipment described in this solution during normal use.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0032] Example 1: A preferred embodiment of the present invention provides a dual-unit reverse coaxial loudspeaker, such as... Figures 1 to 3 As shown, it includes a basin frame body 11, two sets of sound generating units 12, and a sealed outer cover 13. The basin frame body 11 and the two sets of sound generating units 12 are all located inside the sealed outer cover 13. The sealed outer cover 13 provides physical protection for the internal components and together with the basin frame body 11, it forms an acoustic cavity.

[0033] Specifically, the basin frame body 11 is a one-piece molded structure, such as using mature high-strength engineering plastics or metal integral die casting or injection molding. The basin frame body 11 includes a base column 111, and mounting brackets 112 are respectively provided at the upper and lower ends of the base column 111, which are fixedly connected to the sealed outer cover 13. The base column 111 is a cylindrical structure, and the mounting bracket 112 is a disc structure coaxial with it, with a diameter larger than that of the base column 111. The one-piece molded basin frame body 11 eliminates the assembly errors and magnetic leakage gaps caused by traditional split assembly, providing a precise positioning reference for the magnetic circuit system, and enabling the energy of the entire magnetic circuit system to be fully utilized.

[0034] Two sets of sound-generating units 12 are respectively installed in receiving cavities 01 on the two mounting brackets 112. The two mounting brackets 112, the base column 111, and the sealed outer cover 13 enclose each other to form an annular side sound cavity 02. The mounting brackets 112 are provided with multiple through holes 113 in the circumferential direction. The receiving cavity 01 inside the mounting brackets 112 is connected to the side sound cavity 02 through the multiple through holes 113. The sealed outer cover 13 is also provided with a sound outlet 131 that is connected to the side sound cavity 02. The sound outlet 131 serves as the terminal outlet of the entire lateral sound generation path, guiding the sound pressure gathered in the side sound cavity 02 radially to the external environment, thereby achieving efficient and smooth radiation of sound waves and avoiding the accumulation and cancellation of internal sound waves.

[0035] like Figure 4-7As shown, both sets of sound-generating units 12 are coaxial with the base column 111, and the sound-generating ends of the two sets of sound-generating units 12 are arranged facing each other, thus forming a reverse sound-generating structure. Specifically, the "reverse" in this embodiment means that the sound-generating ends (i.e., diaphragm sides) of the two sets of speakers 123 are both facing inward, that is, facing the base column 111, which is different from the sound-generating method of traditional loudspeakers where the speakers emit sound outward (i.e., away from the base column). This inward facing structural design makes the vibration directions of the two sets of diaphragms completely opposite. During operation, the sound emitted by the sound-generating units 12 flows sequentially through the receiving cavity 01 and the through hole 113 into the side sound cavity 02, and finally radiates outward through the sound outlet 131, forming a lateral sound-generating path. This lateral sound-emitting design is different from the axial sound emission of traditional loudspeakers. When assembling end products (such as ultra-thin electronic devices), the annular side sound cavity 02 provides a key convergence and in-phase superposition space for the two sets of sound waves emitting sound in opposite directions. Because the sound-emitting ends of the two sets of sound-generating units face each other, sound waves are prone to collision and phase interference inside. The side sound cavity 02 effectively guides the sound waves to diffuse through the through hole 113 before converging, avoiding direct collision cancellation and disordered reflection of sound waves in the narrow inner cavity, significantly reducing sound energy loss. At the same time, the annular side sound cavity 02, as an acoustic front cavity, plays a role in acoustic impedance matching, which can effectively extend the low-frequency response and enhance the low-frequency sound pressure, making the sound radiated from the sound outlet 131 more robust and full, greatly improving the acoustic performance of the compact structure. In addition, the upper and lower ends of the sealed outer cover 13 are respectively provided with exhaust holes 132 corresponding to the two sets of sound-generating units 12, which are used to allow the sound waves on the back of the sound-generating units 12 to be discharged to balance the air pressure, ensure smooth diaphragm vibration, and reduce nonlinear distortion.

[0036] like Figure 3 As shown, in this embodiment, the mounting bracket 112 includes an annular support plate 1121 extending laterally outward from the outer edge of the base column 111, and a first sidewall 1122 extending longitudinally outward from the outer edge of the annular support plate 1121; the annular support plate 1121, the first sidewall 1122, and the base column 111 mutually enclose each other to form the receiving cavity 01; a plurality of through holes 113 are circumferentially distributed on the annular support plate 1121. The annular support plate 1121 not only provides support for the sound generating unit 12, but its circumferentially distributed through holes 113 also constitute a channel for sound waves to diffuse from the receiving cavity 01 to the outer side sound cavity 02, which is conducive to the uniform convergence of sound waves.

[0037] like Figure 2 and Figure 6As shown, in this embodiment, the sound-generating unit 12 includes a magnetic block 121, a washer block 122, and a speaker 123 arranged sequentially from the inside out; the magnetic block 121, the washer block 122, and the speaker 123 are coaxially arranged. The magnetic block 121 is used to provide a permanent magnetic field, and the washer block 122 is used to guide and concentrate the magnetic lines of force of the magnetic block 121 to the gap of the voice coil of the speaker 123, forming a uniform annular air gap magnetic field; the voice coil of the speaker 123 is inserted into the air gap and is subjected to force under the action of the electromagnetic field of the alternating audio current, which drives the diaphragm to vibrate and generate sound. The sound-generating end (i.e., the diaphragm side) of the speaker 123 faces the washer block 122, and the exhaust end (i.e., the back side of the diaphragm) of the speaker 123 faces away from the washer block 122 and towards the exhaust port 132.

[0038] The working principle of this dual-unit loudspeaker is based on Fleming's left-hand rule: a current-carrying conductor in a magnetic field experiences electromagnetic force, causing the diaphragm to vibrate and produce sound, thus converting electrical signals into sound signals. Specifically, the voice coil of the speaker 123 is inserted into the annular air gap magnetic field formed by the magnetic block 121 and the washer block 122. Driven by an alternating audio current, it is subjected to force, causing the diaphragm to vibrate. The sound waves emitted from the back of the diaphragm flow through the receiving cavity 01 and the through hole 113 into the side sound cavity 02, and finally radiate outward through the sound outlet 131, forming a lateral sound path. In this architecture, since the two sets of sound-producing units are arranged in opposite directions and their diaphragms vibrate in opposite directions, the sound waves are ultimately superimposed in the same direction in the side sound cavity 02, further improving the sound radiation efficiency.

[0039] Furthermore, such as Figure 3 As shown, a limiting step 1123 is provided on the first sidewall 1122. The limiting step 1123 provides positioning support for the outer edge of the speaker 123, such as the edge of the diaphragm bracket. This not only facilitates assembly but also ensures the coaxiality of the speaker 123 and the base column 111, ensuring uniform magnetic circuit gap.

[0040] This invention integrates the magnetic circuit systems of two sets of sound-generating units into a single unit using an integrated frame structure, meaning that a single frame body simultaneously supports both magnetic circuit systems. Specifically, the magnets 121 in the two sets of sound-generating units 12 are arranged with opposite magnetization directions, which significantly enhances the magnetic energy of the entire magnetic circuit system, reduces energy loss due to assembly gaps in traditional split designs, and thus improves the overall electroacoustic conversion efficiency. Simultaneously, the voice coils of the two sets of sound-generating units 12 are connected in opposite phases, causing the two diaphragms to vibrate in opposite directions, jointly driving the air to produce sound. Structurally, the sound is converged to the sound outlet via an internal preset path, achieving lateral sound emission.

[0041] In this embodiment, both the upper and lower ends of the base column 111 are provided with coaxially arranged recesses 03 that communicate with the corresponding receiving cavity 01; the magnetic block 121 and the washer block 122 are fixed in the recesses 03, specifically by adhesive or interference fit. The speaker 123 is fixed on the first side wall 1122 of the mounting bracket 112. By embedding the magnetic circuit system in the recesses 03 of the base column 111, the magnetic leakage path between the magnetic circuit and the supporting structure is greatly shortened, further improving the electromagnetic efficiency. The inner side wall of the recess 03 and the sound-generating unit 12 are provided with a gap, which constitutes a sound wave guiding channel, allowing the sound inside the recess 03 (i.e., between the speaker's sound-generating end and the washer) to flow through the gap from the through hole 113 to the side sound cavity 02.

[0042] Preferably, such as Figure 6 As shown, the opening end face of the cavity 03 is flush with or slightly lower than the end face of the washer block 122, so that the sound waves emitted by the sound-emitting end of the speaker 123 can enter the gap smoothly and without obstruction after passing the washer block 122, avoiding sound obstruction or sound reflection caused by excessive step height, reducing high frequency loss, and ensuring that the sound waves flow efficiently to the through hole 113.

[0043] like Figure 2 As shown, in this embodiment, the sealed outer cover 13 includes an annular second sidewall 133 and two sealing plates 134 respectively fixed to the upper and lower ends of the second sidewall 133 by means such as ultrasonic welding, adhesive bonding or snap-fit ​​connection. The two sealing plates 134 are used to seal the upper and lower end faces of the side sound cavity 02 to prevent air leakage from the side sound cavity 02 and ensure low frequency sound pressure. The sound outlet 131 is located on the second sidewall 133. The two exhaust holes 132 are respectively located on the two sealing plates 134 and are directly opposite the exhaust end of the corresponding sound unit 12.

[0044] like Figure 2 As shown and Figure 6 As shown, in this embodiment, the sealed outer cover 13 is provided with tuning mesh 135 at both of the two exhaust holes 132. The tuning mesh 135 is used to dampen and adjust the airflow and back sound waves discharged from the exhaust holes 132, suppress the "wind noise" and distortion generated by the high-speed airflow, and optimize the low-frequency resonance frequency (F0) and low-frequency response curve of the speaker by adjusting the sound damping.

[0045] Specifically, its acoustic principle is as follows: the tuning mesh 135 is usually made of microporous breathable material (such as damping mesh or porous metal mesh). When the diaphragm of the sound-generating unit 12 vibrates significantly, high-speed alternating airflow and back sound waves are generated at the exhaust port 132. When these airflows and sound waves are forced to pass through the tiny pores of the tuning mesh 135, a strong viscous friction effect is generated between the air molecules and the pore walls, converting some of the sound energy and airflow energy into tiny amounts of heat energy that dissipates, thereby forming acoustic damping (acoustic impedance).

[0046] On the one hand, in suppressing "wind noise" and distortion: when the diaphragm's movement amplitude is too large, if the exhaust port 132 is fully open, the high-speed airflow will separate at the edge of the port, generating turbulence and eddies, which in turn produces a harsh "puffing" or "hissing" sound (i.e., wind noise). The damping effect of the tuning mesh 135 is equivalent to adding a "deceleration buffer" to the airflow, effectively smoothing out the sudden change in airflow velocity and breaking the conditions for eddy formation, thus fundamentally suppressing the generation of wind noise; at the same time, the controlled exhaust airflow avoids the uncontrollable reverse restraint force on the diaphragm caused by the instantaneous and rapid release of air pressure, ensuring that the diaphragm moves precisely according to the electrical signal command, and significantly reducing nonlinear distortion.

[0047] On the other hand, regarding the optimization of the low-frequency resonant frequency (F0) and low-frequency response curve: the low-frequency response of a loudspeaker is highly dependent on the characteristics of the acoustic cavity behind the diaphragm. The acoustic damping provided by the tuning mesh 135, together with the acoustic quality of the vent 132 and the acoustic compliance of the space behind the vent, constitute an acoustic low-pass filter network. Appropriate damping can effectively reduce the quality factor (Q value) of the resonant system, flattening and widening the originally sharp and narrow resonant peak at F0. This not only avoids the "booming" muddiness (standing wave peaks and valleys) in the low-frequency range, but also makes the low-frequency extension deeper and smoother, the frequency response curve cleaner and smoother, and ultimately significantly improves the low-frequency sound quality performance of compact loudspeakers in a limited space.

[0048] In this embodiment, the outer surface of the sealed outer cover 13 is further provided with a voice coil connection PCB 14. The voice coil connection PCB 14 is located on the second sidewall 133 and has multiple conductive terminals, which are electrically connected to the voice coil leads of the two sound-generating units respectively, so as to enable the external audio electrical signal to be electrically connected to either sound-generating unit. Placing the connection PCB externally avoids the interference of traditional internal wiring on sound wave propagation, and also makes soldering and assembly more convenient, improving production yield.

[0049] In summary, compared with the traditional dual-unit design, the present invention has the following significant advantages: a) Significantly improved system magnetic circuit efficiency: The integrated coaxial frame eliminates magnetic leakage gaps, allowing for full utilization of the energy of the entire magnetic circuit system. Simulation comparisons (e.g.) Figure 8As shown in the figure, the electromagnetic efficiency can be improved by more than 15%; under the same magnetic flux conditions, a better sound production effect can be achieved.

[0050] b) Significantly improved acoustic radiation efficiency: Since the two sets of sound generating units are set in opposite directions and the sound waves are ultimately superimposed in the same direction, the lateral sound output path is shorter and smoother, reducing the sound wave reflection loss of traditional axial sound output.

[0051] c) The speaker unit has a simple structure and is easy to manufacture: the integrated frame supports two magnetic circuits and vibration systems at the same time, reducing the number of parts and assembly steps.

[0052] d) Simplified product structure design and installation: This design features rear-mounted sound and a shorter acoustic path, making it particularly suitable for compact electronic devices such as TWS / OWS earphones. It eliminates the need for a sound hole on the front of the product, simplifying the overall structure. Furthermore, since both units share the same frame, its production and manufacturing costs are lower than existing dual-unit designs.

[0053] Example 2: This invention provides a dual-unit reverse coaxial sound generation method, using the dual-unit reverse coaxial loudspeaker as described in Example 1, wherein the method includes the following steps: Step S1: Receive audio electrical signals and drive two sets of sound generating units to vibrate in opposite directions simultaneously based on the precise coaxial positioning provided by the one-piece molded frame. Since the voice coils of the two sets of sound generating units are connected in opposite phases and the magnetic blocks are magnetized in opposite directions, the vibration directions of the two diaphragms are opposite. The sound generating ends of the two sound generating units generate main sound waves facing each other, while the two exhaust ends generate back sound waves facing away from each other, thus realizing efficient conversion of electroacoustic signals. In step S2, the main sound waves generated by the two sound-generating ends first radiate into their respective concave cavities and receiving cavities, and then flow smoothly along the gap between the inner wall of the concave cavity and the sound-generating unit. After passing the washer block, they flow from the inside out through multiple through holes arranged circumferentially on the mounting frame to the annular side sound cavity formed by the two mounting frames, the base column and the sealed outer cover. This flow guiding process avoids the direct collision and phase cancellation of the two sets of opposing main sound waves in the narrow inner cavity, reducing sound energy loss. In step S3, the main sound waves flowing into the annular side acoustic cavity undergo in-phase acoustic coupling and superposition. The annular side acoustic cavity, as an acoustic front cavity, plays the role of acoustic impedance matching, effectively extending the low-frequency response and enhancing the low-frequency sound pressure. Subsequently, the propagation direction of the coupled sound waves is deflected, and the sound waves radiate outward along the radial direction of the loudspeaker through the sound outlet on the sealed outer cover, forming a lateral sound path, which significantly reduces the sound wave reflection loss caused by traditional axial sound output. In step S4, while the main sound wave radiates laterally, the back sound waves generated by the exhaust ends of the two sets of sound units are discharged outward through the exhaust holes at the upper and lower ends of the sealed outer cover, so as to balance the pressure difference between the inside and outside of the sound unit diaphragm when it vibrates, ensure smooth diaphragm vibration and reduce nonlinear distortion. During the discharge of the back sound waves, the airflow and sound waves are also damped by the tuning mesh at the exhaust hole to suppress wind noise generated by high-speed airflow and further optimize the low-frequency resonance frequency and frequency response curve of the loudspeaker.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dual-unit reverse coaxial loudspeaker, characterized in that, The device includes a basin frame body, two sets of sound-generating units, and a sealed outer cover. The basin frame body is a one-piece molded structure, including a base column. The upper and lower ends of the base column are respectively provided with mounting brackets fixedly connected to the sealed outer cover. The two sets of sound-generating units are respectively mounted on the receiving cavities of the two mounting brackets. An annular side sound cavity is formed between the two mounting brackets, the base column, and the sealed outer cover. Multiple through holes are provided circumferentially on the mounting brackets. The receiving cavities are connected to the side sound cavity through the multiple through holes. The sealed outer cover also has a sound outlet hole connected to the side sound cavity. Both sets of sound-generating units are coaxial with the base column, and the sound-generating ends of the two sets of sound-generating units are arranged facing each other to form a reverse sound-generating structure. The sound emitted by the sound-generating units sequentially enters the side sound cavity through the receiving cavity and the through holes, and finally radiates outward through the sound outlet hole, forming a lateral sound path. The upper and lower ends of the sealed outer cover are respectively provided with exhaust holes corresponding to the two sets of sound-generating units, used to allow sound waves from the back of the sound-generating units to escape to balance the air pressure.

2. The dual-unit reverse coaxial loudspeaker according to claim 1, characterized in that, The mounting bracket includes an annular support plate extending laterally outward from the outer edge of the base column, and a first sidewall extending longitudinally outward from the outer edge of the annular support plate; the annular support plate, the first sidewall, and the base column enclose each other to form the receiving cavity; a plurality of through holes are circumferentially distributed on the annular support plate.

3. The dual-unit reverse coaxial loudspeaker according to claim 2, characterized in that, The sound-generating unit includes a magnet, a washer, and a speaker arranged sequentially from the inside out; the magnet, washer, and speaker are coaxially arranged; the magnet provides a magnetic field, the washer guides the magnetic lines of force of the magnet to the gap of the speaker's voice coil, and the speaker's voice coil drives the diaphragm to vibrate and produce sound under the action of the electromagnetic field; the sound-generating end of the speaker faces the washer, and the exhaust end of the speaker faces the exhaust port.

4. The dual-unit reverse coaxial loudspeaker according to claim 3, characterized in that, The first sidewall is provided with a limiting step for positioning the outer edge of the speaker.

5. The dual-unit reverse coaxial loudspeaker according to claim 3 or 4, characterized in that, Both ends of the base column are provided with coaxially arranged concave cavities that are connected to the corresponding receiving cavities; the magnet and the washer are fixed in the concave cavities, and the speaker is fixed on the mounting bracket; a gap is provided between the inner wall of the concave cavity and the sound-generating unit, so that the sound inside the concave cavity flows through the gap from the through hole to the side sound cavity.

6. The dual-unit reverse coaxial loudspeaker according to any one of claims 1-4, characterized in that, The sealed outer cover includes an annular second sidewall and two sealing plates respectively fixed to the upper and lower ends of the second sidewall for sealing the side sound cavity; the sound outlet is located on the second sidewall; the two exhaust holes are respectively located on the two sealing plates.

7. The dual-unit reverse coaxial loudspeaker according to claim 6, characterized in that, The sealed outer cover is equipped with a sound-adjusting mesh at both of the exhaust ports to dampen and adjust the airflow and sound waves discharged from the exhaust ports, thereby suppressing airflow noise.

8. The dual-unit reverse coaxial loudspeaker according to claim 7, characterized in that, The outer surface of the sealed outer cover is also provided with a voice coil connection PCB, which is located on the second side wall and is used to realize the electrical conduction between the external audio electrical signal and the sound-generating unit.

9. The dual-unit reverse coaxial loudspeaker according to claim 1, characterized in that, The opening end face of the cavity is flush with or lower than the end face of the washer, so that the sound waves emitted by the speaker can enter the gap without obstruction.

10. A dual-unit reverse coaxial sound generation method, using a dual-unit reverse coaxial loudspeaker as described in any one of claims 1-9, characterized in that, The method includes the following steps: Step S1: Receive audio electrical signal and drive two sets of coaxially arranged sound generating units to vibrate in opposite directions at the same time, so that the sound generating ends of the two sets of sound generating units face each other to generate main sound waves, while the exhaust ends face away to generate back sound waves. In step S2, the main sound waves generated by the two sound-generating ends first radiate into their respective receiving cavities, and then flow outward from the inside to the annular side sound cavity formed by the two mounting frames, the base column and the sealed outer cover through multiple through holes arranged circumferentially on the mounting frame. Step S3: The main sound wave flowing into the side sound cavity undergoes acoustic coupling, and then radiates outward through the sound outlet on the sealed outer cover, forming a side sound path. In step S4, while the main sound wave radiates laterally, the back sound waves generated by the exhaust ends of the two sets of sound generating units are discharged outward through the exhaust holes at the upper and lower ends of the sealed outer cover, so as to balance the pressure difference between the inside and outside of the sound generating unit when it vibrates.

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