Micro loudspeaker with electromagnetic amplitude adjustment function and adjustment method thereof

Abstract

The invention discloses a micro loudspeaker with electromagnetic amplitude adjustment and an adjustment method thereof, the micro loudspeaker comprises a vibrating diaphragm upper cover, the bottom of the vibrating diaphragm upper cover is fixedly connected with a vibrating diaphragm voice coil assembly, and the bottom of the vibrating diaphragm voice coil assembly is fixedly connected with a frame; an upper magnet is fixedly installed on the top of an inner cavity of the vibrating diaphragm upper cover, the upper coil is fixedly installed on a folding ring on the top of the vibrating diaphragm voice coil assembly, and a loudspeaker magnet is fixedly connected to the bottom of an inner cavity of the frame. According to the invention, the problem that the cost and the mass production feasibility are difficult to consider when the rolling vibration of the voice coil of the existing micro-loudspeaker is improved by coating damping glue or depending on complex structural design is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of loudspeakers, and in particular to a micro-loudspeaker with electromagnetic amplitude adjustment and an adjustment method thereof. Background Art

[0002] As a key audio output component in modern electronic devices, the performance of micro speakers directly affects the sound quality. Traditional micro speakers use the voice coil to drive the diaphragm to vibrate in the magnetic field, thereby pushing the air to produce sound. However, the uniform distribution area of ​​the magnetic field where the voice coil is located is limited by the magnetic circuit design, and a relatively uniform magnetic field strength is usually only achieved in the middle area of ​​the magnetic gap. According to Ampere's law F=BLI, when the voice coil moves beyond the uniform magnetic field area due to large amplitude, the B value will change significantly, resulting in uneven force on the voice coil, which in turn causes irregular movement of the diaphragm, that is, rolling vibration. This rolling vibration will destroy the linear vibration characteristics of the diaphragm, causing problems such as frequency response distortion and sound quality degradation, especially in low-frequency and large dynamic scenes.

[0003] Currently, the industry generally uses damping adhesive to suppress rolling vibrations. However, this technology relies on a highly precise adhesive coating process. In actual production, the adhesive is prone to problems such as bubbles, needle clogging, and uneven thickness, resulting in uneven distribution of the damping adhesive. This not only fails to effectively balance the forces acting on the voice coil, but can also exacerbate localized stress concentrations, further exacerbating rolling vibrations. Furthermore, the damping adhesive's curing properties, adhesion strength, and environmental stability place higher demands on process control, increasing production costs and yield risks.

[0004] While existing technologies have addressed rolling vibration by optimizing magnetic circuit structures or improving diaphragm materials, these approaches often rely on complex structural designs and struggle to balance cost and mass production feasibility. Therefore, a new solution is urgently needed that can effectively suppress large-amplitude rolling vibration while avoiding process defects, thereby improving the acoustic performance and reliability of microspeakers. Summary of the Invention

[0005] The purpose of the present invention is to provide a micro-speaker with electromagnetic amplitude adjustment and an adjustment method thereof, which solves the problem that existing micro-speakers, when improving the rolling vibration of the voice coil, are achieved by coating damping glue or relying on complex structural design, which makes it difficult to balance cost and mass production feasibility.

[0006] To achieve the above object, the present invention provides the following technical solution: a micro-speaker with electromagnetic amplitude adjustment, comprising a diaphragm cover, a diaphragm voice coil assembly fixedly connected to the bottom of the diaphragm cover, and a basin frame fixedly connected to the bottom of the diaphragm voice coil assembly;

[0007] An upper magnet is fixedly mounted on the top of the inner cavity of the diaphragm upper cover, the upper coil is fixedly mounted on the folding ring at the top of the diaphragm voice coil assembly, and a loudspeaker magnet is fixedly connected to the bottom of the inner cavity of the basin frame.

[0008] As a preferred micro-speaker with electromagnetic amplitude adjustment of the present invention, a washer is fixedly installed on the top of the speaker magnet, and the washer is located at the bottom of the diaphragm voice coil assembly.

[0009] As a preferred embodiment of the micro-speaker with electromagnetic amplitude adjustment of the present invention, the upper coil is located at an end opposite to the upper magnet and the speaker magnet, and is simultaneously located in the magnetic fields of the upper magnet and the speaker magnet.

[0010] As a preferred micro-speaker with electromagnetic amplitude adjustment of the present invention, a PCB board is fixedly installed on the bottom of the diaphragm cover, and two groups of wiring ports are provided on the PCB board, one group of wiring ports is electrically connected to the diaphragm voice coil assembly, and the other group of wiring ports is electrically connected to the upper coil.

[0011] As a preferred embodiment of the micro-speaker with electromagnetic amplitude adjustment of the present invention, the PCB board is provided with a capacitor element and an inductor element.

[0012] As a preferred embodiment of the micro-speaker with electromagnetic amplitude adjustment of the present invention, a limiting groove for use with the upper magnet is provided at the bottom of the diaphragm upper cover.

[0013] As a preferred embodiment of the micro-speaker with electromagnetic amplitude adjustment of the present invention, a plurality of sound outlet holes are provided on the top of the diaphragm upper cover.

[0014] As a preferred micro-speaker with electromagnetic amplitude adjustment of the present invention, the negative pole of the upper coil is electrically connected to the positive pole of the diaphragm voice coil assembly, and the positive pole of the upper coil is electrically connected to the negative pole of the diaphragm voice coil assembly.

[0015] As a preferred embodiment of the micro-speaker with electromagnetic amplitude adjustment of the present invention, the upper magnet and the speaker magnet have the same magnetizing direction.

[0016] A method for adjusting a micro-speaker with electromagnetic amplitude adjustment comprises the following steps:

[0017] S1. The audio signal first enters the PCB board. The signal is transmitted to the diaphragm voice coil assembly and the upper coil through two sets of connection ports on the PCB board.

[0018] S2. The audio signal directly acts on the voice coil of the diaphragm voice coil assembly, causing it to vibrate in the magnetic field formed by the washer and the speaker magnet, which in turn drives the diaphragm of the diaphragm voice coil assembly to produce sound. At the same time, the audio signal is processed by the low-pass filter circuit composed of capacitors and inductors, allowing only low-frequency signals to be transmitted to the upper coil;

[0019] S3. Since the positive pole of the upper coil is connected to the negative pole of the diaphragm voice coil assembly, and the negative pole of the upper coil is connected to the positive pole of the diaphragm voice coil assembly, the current directions of the two are opposite. Thus, under the drive of the audio signal, the magnetic fields generated by the diaphragm voice coil assembly and the upper coil are also in opposite directions.

[0020] S4. When the diaphragm voice coil assembly tends to deviate from the axis due to large-amplitude motion and produces rolling vibration, the upper coil is located in the magnetic field formed between the upper magnet and the speaker magnet. According to the left-hand rule, the reverse magnetic field it generates will apply a force on the diaphragm voice coil assembly in the opposite direction of its motion. This reverse force offsets the nonlinear force that causes rolling vibration, allowing the diaphragm voice coil assembly to maintain a more stable axial vibration, thereby reducing the occurrence of rolling vibration, improving the quality of sound output, and ensuring the stability and reliability of the speaker under large-amplitude working conditions.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention effectively suppresses the rolling vibration phenomenon commonly seen in speakers operating at large amplitudes by introducing an electromagnetic regulation mechanism that combines an upper coil with a low-pass filter circuit in the micro-speaker. The upper coil is cross-connected in parallel with the main voice coil and is located in the magnetic field formed by the upper magnet and the speaker magnet. During large-amplitude movement, it can be divided into upward and downward movements. During upward movement, the upper coil is mainly affected by the magnetic force of the upper magnet, while during downward movement, the upper coil is mainly affected by the magnetic force of the speaker magnet. Driven by a low-frequency signal, the upper coil generates a magnetic field in the opposite direction to that of the main voice coil, thereby forming an antagonistic restoring force. This restoring force can promptly pull back or suppress the voice coil when it deviates from its axis, significantly reducing harmonic distortion and intermodulation distortion caused by mechanical nonlinearity, and improving the clarity and fidelity of the audio output. In addition, since it only works in the low-frequency band, the high-frequency response is not disturbed, ensuring the natural and balanced overall frequency response of the speaker.

[0023] 2. The present invention not only has obvious advantages in electroacoustic performance, but also shows good application value in mechanical structure protection. The reverse force generated by the upper coil provides an upward pulling force when the voice coil moves downward and approaches the bottom of the basin frame to prevent the "bottoming out" phenomenon. It provides downward pressure when the voice coil moves upward and approaches the limit to avoid the risk of damage caused by "overstroke". This active electromagnetic assisted control method enhances the stability and controllability of the voice coil movement and extends the service life of the speaker. It is particularly suitable for miniaturized, high-power density micro-speaker application scenarios. At the same time, combined with the limit slot design on the PCB board, the sound hole layout and the washer-optimized magnetic circuit and other structural features, the product's integration, heat dissipation performance and assembly accuracy are further improved, providing reliable technical support for the mass production and wide application of high-performance micro-speakers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention;

[0025] Figure 2 It is an exploded view of the present invention;

[0026] Figure 3 It is a cross-sectional view of the present invention;

[0027] Figure 4 Schematic diagram of the internal structure of the diaphragm cover of the present invention Figure 1 ;

[0028] Figure 5 Schematic diagram of the internal structure of the diaphragm cover of the present invention Figure 2 ;

[0029] Figure 6 This is a schematic diagram of the working principle of the present invention;

[0030] Figure 7 This is a simulation force analysis diagram of the present invention.

[0031] In the figure: 1. Diaphragm cover; 2. Upper magnet; 3. Upper coil; 4. Diaphragm voice coil assembly; 5. Washer; 6. Speaker magnet; 7. Basin; 8. PCB board; 9. Limit slot; 10. Sound outlet. DETAILED DESCRIPTION

[0032] Example 1

[0033] See also Figure 1-Figure 7 A micro speaker with electromagnetic amplitude adjustment includes a diaphragm cover 1, a diaphragm voice coil assembly 4 is fixedly connected to the bottom of the diaphragm cover 1, and a basin frame 7 is fixedly connected to the bottom of the diaphragm voice coil assembly 4.

[0034] Furthermore, an upper magnet 2 is fixedly mounted on the top of the inner cavity of the diaphragm upper cover 1, an upper coil 3 is fixedly mounted on the folding ring at the top of the diaphragm voice coil assembly 4, and a speaker magnet 6 is fixedly connected to the bottom of the inner cavity of the basin frame 7.

[0035] Furthermore, a washer 5 is fixedly mounted on the top of the speaker magnet 6 , and the washer 5 is located at the bottom of the diaphragm voice coil assembly 4 .

[0036] Furthermore, the upper coil 3 is located at an end opposite to the upper magnet 2 and the speaker magnet 6 , and is simultaneously located within the magnetic fields of the upper magnet 2 and the speaker magnet 6 .

[0037] Furthermore, a PCB board 8 is fixedly mounted on the bottom of the diaphragm cover 1 , and two groups of wiring ports are provided on the PCB board 8 , one group of wiring ports is electrically connected to the diaphragm voice coil assembly 4 , and the other group of wiring ports is electrically connected to the upper coil 3 .

[0038] Furthermore, capacitor elements and inductor elements are provided on the PCB board 8 .

[0039] Furthermore, a limiting groove 9 for use with the upper magnet 2 is provided at the bottom of the diaphragm upper cover 1 .

[0040] Furthermore, a plurality of sound holes 10 are provided on the top of the diaphragm upper cover 1 .

[0041] Furthermore, the negative pole of the upper coil 3 is electrically connected to the positive pole of the diaphragm voice coil assembly 4 , and the positive pole of the upper coil 3 is electrically connected to the negative pole of the diaphragm voice coil assembly 4 .

[0042] Furthermore, the upper magnet 2 and the speaker magnet 6 have the same magnetizing direction.

[0043] Example 2

[0044] See also Figure 1-Figure 7 A method for adjusting a micro-speaker with electromagnetic amplitude adjustment comprises the following steps:

[0045] S1, the audio signal first enters the PCB board 8, and the signal is transmitted to the diaphragm voice coil assembly 4 and the upper coil 3 respectively through the two sets of connection ports on the PCB board 8;

[0046] S2: The audio signal directly acts on the voice coil of the diaphragm voice coil assembly 4, causing it to vibrate in the magnetic field formed by the washer 5 and the speaker magnet 6, thereby driving the diaphragm of the diaphragm voice coil assembly 4 to produce sound. The sound emitted enters the outside through the sound outlet 10. At the same time, the audio signal is processed by the low-pass filter circuit composed of capacitors and inductors, allowing only low-frequency signals to be transmitted to the upper coil 3;

[0047] S3. Since the positive pole of the upper coil 3 is connected to the negative pole of the diaphragm voice coil assembly 4, and the negative pole of the upper coil 3 is connected to the positive pole of the diaphragm voice coil assembly 4, the current directions of the two are opposite. Thus, under the drive of the audio signal, the magnetic fields generated by the diaphragm voice coil assembly 4 and the upper coil 3 are also in opposite directions.

[0048] S4. When the diaphragm voice coil assembly 4 tends to deviate from the axis due to large-amplitude movement and produces rolling vibration, the upper coil 3 is located in the magnetic field formed between the upper magnet 2 and the speaker magnet 6. According to the left-hand rule, the reverse magnetic field it generates will apply a force to the diaphragm voice coil assembly 4 in the opposite direction of its movement. This reverse force offsets the nonlinear force that causes the rolling vibration, allowing the diaphragm voice coil assembly 4 to maintain a more stable axial vibration, thereby reducing the occurrence of rolling vibration, improving the quality of sound output, and ensuring the stability and reliability of the speaker under large-amplitude working conditions.

[0049] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A micro-speaker with electromagnetic amplitude adjustment, comprising a diaphragm cover (1), characterized in that: The bottom of the diaphragm upper cover (1) is fixedly connected to a diaphragm voice coil assembly (4), and the bottom of the diaphragm voice coil assembly (4) is fixedly connected to a basin frame (7); An upper magnet (2) is fixedly mounted on the top of the inner cavity of the diaphragm upper cover (1), the upper coil (3) is fixedly mounted on the folded ring at the top of the diaphragm voice coil assembly (4), and a loudspeaker magnet (6) is fixedly connected to the bottom of the inner cavity of the basin frame (7).

2. The micro-speaker with electromagnetic amplitude adjustment according to claim 1, characterized in that: A washer (5) is fixedly mounted on the top of the loudspeaker magnet (6), and the washer (5) is located at the bottom of the diaphragm voice coil assembly (4).

3. The micro-speaker with electromagnetic amplitude adjustment according to claim 2, characterized in that: The upper coil (3) is located at an end opposite to the upper magnet (2) and the speaker magnet (6), and is simultaneously located within the magnetic fields of the upper magnet (2) and the speaker magnet (6).

4. The micro-speaker with electromagnetic amplitude adjustment according to claim 3, characterized in that: A PCB board (8) is fixedly mounted on the bottom of the diaphragm upper cover (1), and two groups of connection ports are provided on the PCB board (8), one group of connection ports is electrically connected to the diaphragm voice coil assembly (4), and the other group of connection ports is electrically connected to the upper coil (3).

5. The micro-speaker with electromagnetic amplitude adjustment according to claim 4, characterized in that: The PCB board (8) is provided with a capacitor element and an inductor element.

6. The micro-speaker with electromagnetic amplitude adjustment according to claim 5, characterized in that: The bottom of the diaphragm upper cover (1) is provided with a limiting groove (9) for use with the upper magnet (2).

7. The micro-speaker with electromagnetic amplitude adjustment according to claim 6, characterized in that: A plurality of sound outlet holes (10) are provided on the top of the diaphragm upper cover (1).

8. The micro-speaker with electromagnetic amplitude adjustment according to claim 7, characterized in that: The negative pole of the upper coil (3) is electrically connected to the positive pole of the diaphragm voice coil assembly (4), and the positive pole of the upper coil (3) is electrically connected to the negative pole of the diaphragm voice coil assembly (4).

9. The micro-speaker with electromagnetic amplitude adjustment according to claim 8, characterized in that: The upper magnet (2) and the speaker magnet (6) have the same magnetizing direction.

10. A method for adjusting a micro-speaker with electromagnetically adjustable amplitude, applicable to the micro-speaker with electromagnetically adjustable amplitude according to claim 9, characterized in that: The following steps are involved: S1, the audio signal first enters the PCB board (8), and the signal is transmitted to the diaphragm voice coil assembly (4) and the upper coil (3) respectively through two groups of connection ports on the PCB board (8); S2, the audio signal directly acts on the voice coil on the diaphragm voice coil assembly (4), causing it to generate corresponding vibrations in the magnetic field formed by the washer (5) and the speaker magnet (6), thereby driving the diaphragm on the diaphragm voice coil assembly (4) to produce sound. At the same time, the audio signal is also processed by a low-pass filter circuit composed of a capacitor and an inductor, allowing only low-frequency signals to be transmitted to the upper coil (3); S3. Since the positive pole of the upper coil (3) is connected to the negative pole of the diaphragm voice coil assembly (4), and the negative pole of the upper coil (3) is connected to the positive pole of the diaphragm voice coil assembly (4), the directions of the currents therethrough are opposite. Thus, under the drive of the audio signal, the directions of the magnetic fields generated by the diaphragm voice coil assembly (4) and the upper coil (3) are also opposite. S4. When the diaphragm voice coil assembly (4) tends to deviate from the axis due to large-amplitude motion and produces rolling vibration, the upper coil (3) is located in the magnetic field formed between the upper magnet (2) and the speaker magnet (6). According to the left-hand rule, the reverse magnetic field generated by it will apply a force opposite to the direction of its motion to the diaphragm voice coil assembly (4). This reverse force offsets the nonlinear force causing the rolling vibration, allowing the diaphragm voice coil assembly (4) to maintain a more stable axial vibration, thereby reducing the occurrence of the rolling vibration phenomenon, improving the quality of the sound output, and ensuring the stability and reliability of the speaker under large-amplitude working conditions.

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