CN221177913U

CN221177913U - Micro-speaker and acoustic device

Info

Publication number: CN221177913U
Application number: CN202322606544.XU
Authority: CN
Inventors: 蔡晓东; 刘松; 李波波
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2023-09-22
Filing date: 2023-09-22
Publication date: 2024-06-18
Anticipated expiration: 2033-09-22

Abstract

The utility model discloses a miniature loudspeaker and an acoustic device, the miniature loudspeaker comprises a shell, a magnetic circuit system and a vibration system, wherein the magnetic circuit system is fixed on the shell, the magnetic circuit system comprises a magnetic yoke, a central magnetic part, an inner magnetic part and an outer magnetic part, the central magnetic part, the inner magnetic part and the outer magnetic part are arranged in a surrounding manner, an inner magnetic gap is formed between the inner magnetic part and the central magnetic part, the outer magnetic part and the inner magnetic part are arranged in a surrounding manner, an outer magnetic gap is formed between the outer magnetic part and the inner magnetic part, the vibration system comprises a vibrating diaphragm and a voice coil assembly for driving the vibrating diaphragm to vibrate, the voice coil assembly comprises an inner voice coil and an outer voice coil arranged around the inner voice coil, the inner voice coil is arranged in the inner magnetic gap, the outer voice coil is arranged in the outer magnetic gap, the vibrating diaphragm comprises a first folding ring, a vibrating part and a second folding ring which are sequentially connected from outside to inside, the first folding ring comprises an outer fixing part, the outer fixing part is fixed on the shell, and the second folding ring comprises an inner fixing part and the inner fixing part is fixed on the central magnetic part. The micro-speaker of the present utility model has higher loudness and sensitivity.

Description

Micro-speaker and acoustic device

Technical Field

The present utility model relates to electroacoustic conversion technology, and more particularly, to a micro speaker and an acoustic device using the same.

Background

The micro-speaker is widely applied to modern portable, communication and intelligent devices due to the small size, and the requirements of users on high sound quality are increasing, especially for some portable intelligent devices, the users are not satisfied with the presence or absence of sound, but more pursue good sound quality.

Loudness (sensitivity) is a main indicator for measuring the performance of a micro-speaker, and the skilled person finds that when the back cavity of the micro-speaker is small, the driving force factor BL value and the effective vibration area Sd of the diaphragm are key factors affecting the sensitivity. In one aspect, the skilled person is working to improve the magnetic circuit to boost the BL value of the loudspeaker. On the other hand, when researching to raise BL value, also researching how to design the combination of vibrating diaphragm and magnetic circuit to make miniature loudspeaker obtain better acoustic effect, satisfy customer's demand to tone quality.

Disclosure of utility model

The main object of the present utility model is to provide a micro-speaker and an acoustic device, which aim to improve the loudness and sensitivity of the micro-speaker by improving the magnetic circuit system and the vibration system of the micro-speaker.

In order to achieve the above object, the present utility model provides a micro speaker, the micro speaker includes a housing, and a vibration system and a magnetic circuit fixed to the housing, the magnetic circuit includes a yoke, a central magnetic portion, an inner magnetic portion and an outer magnetic portion that are disposed apart from each other in the yoke, the inner magnetic portion is disposed around the central magnetic portion and forms an inner magnetic gap therebetween, the outer magnetic portion is disposed around the inner magnetic portion and forms an outer magnetic gap therebetween, the vibration system includes a diaphragm and a voice coil assembly for driving the diaphragm to vibrate, the voice coil assembly includes an inner voice coil and an outer voice coil disposed around the inner voice coil, the inner voice coil is disposed in the inner magnetic gap, the outer voice coil is disposed in the outer magnetic gap, the diaphragm includes a first folder, a vibration portion, and a second folder that are sequentially connected from outside to inside, the first folder includes an outer fixing portion, the outer fixing portion is fixed to the housing, and the second folder includes an inner fixing portion fixed to the central magnetic portion.

In an embodiment, the central magnetic part comprises a central magnet and a central magnetic conduction plate which are sequentially overlapped on the magnetic yoke, the inner magnetic part comprises an inner magnet and an inner magnetic conduction plate which are sequentially overlapped on the magnetic yoke, the outer magnetic part comprises an outer magnet and an outer magnetic conduction plate which are sequentially overlapped on the magnetic yoke, an inner magnetic gap is formed between the central magnetic conduction plate and the inner magnetic conduction plate, and an outer magnetic gap is formed between the inner magnetic conduction plate and the outer magnetic conduction plate.

In an embodiment, the center magnet, the inner magnet and the outer magnet are magnetized along the vibration direction of the vibrating diaphragm, the magnetizing directions of the center magnet and the inner magnet are opposite, and the magnetizing directions of the center magnet and the outer magnet are the same.

In an embodiment, the micro speaker further includes an elastic support piece, the elastic support piece includes an inner connection portion connected with the voice coil assembly, an outer connection portion connected with the housing, and a deformation portion connecting the inner connection portion and the outer connection portion.

In an embodiment, the elastic support piece includes a plurality of, and a plurality of the elastic support piece is located at intervals the voice coil assembly is kept away from one side of vibrating diaphragm, magnetic circuit is provided with dodges the clearance is dodged to the elastic support piece.

In an embodiment, the inner connecting portion includes a first connecting portion connected with the inner voice coil, a second connecting portion connected with the outer voice coil, and a middle portion connecting the first connecting portion and the second connecting portion, the inner magnetic portion has a first avoiding gap avoiding the middle portion, the outer magnetic portion has a second avoiding gap avoiding the deformation portion, and the first avoiding gap and the second avoiding gap are correspondingly communicated to form the avoiding gap.

In an embodiment, the elastic support pieces include four, and the four elastic support pieces are respectively disposed at four corners of the voice coil assembly.

In an embodiment, the elastic support pieces include two, and the two elastic support pieces are respectively disposed on two opposite sides of the voice coil assembly.

In an embodiment, the elastic support piece comprises four, at least three of the four elastic support pieces are conductive support pieces, and the inner voice coil and the outer voice coil are connected in series through the conductive support pieces and are electrically connected with an external circuit.

In an embodiment, the first folding ring is arranged to be protruded towards a direction close to the magnetic circuit system, and the second folding ring is arranged to be protruded towards a direction far away from the magnetic circuit system.

The utility model also provides an acoustic device which comprises a shell and the micro loudspeaker.

According to the miniature loudspeaker, the central magnetic part is additionally arranged on the inner side of the inner magnetic part, an inner magnetic gap is formed between the central magnetic part and the inner magnetic part, meanwhile, an outer magnetic gap is formed between the inner magnetic part and the outer magnetic part, the inner voice coil is arranged in the inner magnetic gap, the outer voice coil is arranged in the outer magnetic gap, and the inner voice coil and the outer voice coil are stressed in the magnetic gaps to drive the vibrating diaphragm to vibrate and sound. The central magnetic part fully utilizes the central area of the magnetic circuit system, and the magnetic field strength and the BL value of the micro-speaker are improved under the condition that the product size is not increased. Simultaneously, be fixed in central magnetic part and shell respectively through setting up the both sides of vibrating diaphragm, through reducing the effective vibrating area of vibrating diaphragm, can further promote micro-speaker's sound pressure level, especially the sound pressure level of low frequency channel, promote micro-speaker's loudness and sensitivity.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a micro-speaker according to the present utility model;

FIG. 2 is a schematic view of a micro-speaker according to another embodiment of the present utility model;

fig. 3 is a schematic diagram showing the separation of the housing, vibration system and magnetic circuit system of the micro-speaker of the present utility model;

FIG. 4 is an exploded view of a micro-speaker of the present utility model;

FIG. 5 is a schematic top view of a micro-speaker according to an embodiment of the present utility model;

FIG. 6 is a schematic cross-sectional view of a micro-speaker of an embodiment taken along line A-A of FIG. 5;

FIG. 7 is a schematic cross-sectional view of a micro-speaker of an embodiment taken along line A-A of FIG. 5;

FIG. 8 is a schematic diagram showing the combination of a voice coil assembly and a resilient support of a micro-speaker according to one embodiment;

fig. 9 is a schematic diagram showing the separation of the magnetic circuit system and other components of the micro-speaker according to an embodiment.

Reference numerals illustrate:

the achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present utility model are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

Meanwhile, the meaning of "and/or" and/or "appearing throughout the text is to include three schemes, taking" a and/or B "as an example, including a scheme, or B scheme, or a scheme that a and B satisfy simultaneously.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

Loudness (sensitivity) is a main indicator for measuring the performance of a micro-speaker, and the skilled person finds that when the back cavity of the micro-speaker is small, the driving force factor BL value and the effective vibration area Sd of the diaphragm are key factors affecting the sensitivity. In one aspect, the skilled person is working to improve the magnetic circuit system to boost the BL value of the speaker. On the other hand, when researching to raise BL value, also researching how to design the combination of vibrating diaphragm and magnetic circuit to make miniature loudspeaker obtain better acoustic effect, satisfy customer's demand to tone quality.

Based on the above problems, the present solution provides a micro speaker, which includes a vibration system and a magnetic circuit system, wherein the magnetic circuit system has a magnetic gap, and a voice coil of the vibration system is disposed in the magnetic gap and is vibrated by force to drive a vibrating diaphragm to vibrate and sound. The acoustic device in this embodiment may be a portable mobile electronic product such as a mobile phone and an IPAD, or a wearable device such as a wristwatch, VR, AR, etc., which is not limited herein.

Referring to fig. 1 to 9, in the embodiment of the utility model, the micro-speaker 100 includes a housing 1, a vibration system 2 and a magnetic circuit 3 fixed to the housing 1, the magnetic circuit 3 includes a yoke 31, a central magnetic portion 32 spaced apart from the yoke 31, an inner magnetic portion 33 and an outer magnetic portion 34, the inner magnetic portion 33 is disposed around the central magnetic portion 32 with an inner magnetic gap formed therebetween, the outer magnetic portion 34 is disposed around the inner magnetic portion 33 with an outer magnetic gap formed therebetween, the vibration system 2 includes a diaphragm 21 and a voice coil assembly 22 for driving the diaphragm 21 to vibrate, the voice coil assembly 22 includes an inner voice coil 221 and an outer voice coil 222 disposed around the inner voice coil 221, the inner voice coil 221 is disposed in the inner magnetic gap, and the outer voice coil 222 is disposed in the outer magnetic gap.

In this embodiment, the casing 1 is used for supporting and fixing the vibration system 2 and the magnetic circuit system 3, and the casing 1 may be made of metal, plastic or the casing 1 is formed by combining a metal piece and a plastic piece. When the shell 1 is made of metal, the magnetic circuit 3 can be bonded or welded with the shell 1 or the shell 1 and the magnetic circuit 3 are integrally formed; when the housing 1 is made of plastic, the housing 1 and the magnetic circuit 3 are formed in a split manner, and a part of the magnetic components of the magnetic circuit 3 can be injection molded with the housing 1, and the rest of the magnetic components are further bonded, etc., without limitation.

The magnetic circuit 3 includes a yoke 31, a central magnetic portion 32, an inner magnetic portion 33 and an outer magnetic portion 34 which are alternately provided on the yoke 31, and the outer magnetic portion 34 is connected to the housing 1 to fix the magnetic circuit 3 to the housing 1. In the magnetic circuit 3, the inner magnetic portion 33 is disposed around the center magnetic portion 32 with an inner magnetic gap formed therebetween, and the outer magnetic portion 34 is disposed around the inner magnetic portion 33 with an outer magnetic gap formed therebetween. Compared with the conventional magnetic circuit loudspeaker, the central magnetic circuit loudspeaker has the advantages that the central magnetic part 32 is additionally arranged at the central part of the middle magnetic circuit of the conventional loudspeaker under the condition that the utilization rate of the central part of the middle magnetic circuit loudspeaker is lower, so that a magnetic gap is formed between the central magnetic part 32 and the outer inner magnetic part 33, the utilization rate of the magnet is improved, and the magnetic field intensity in the magnetic circuit system 3 is improved. In the micro-speaker 100 of the present utility model, the voice coil assembly 22 can use not only the magnetic field between the inner magnetic part 33 and the outer magnetic part 34, but also the magnetic field between the inner magnetic part 33 and the center magnetic part 32, so as to greatly increase the BL value of the micro-speaker 100 and thus the acoustic performance of the micro-speaker 100, without changing the product size. It will be appreciated that the inner magnetic portion 33 may be annular or a plurality of spaced apart portions surrounding the central magnetic portion 32, and the outer magnetic portion 34 may be annular or a plurality of spaced apart portions surrounding the inner magnetic portion 33, as not limited herein.

In an embodiment, as shown in fig. 4 and 7, the diaphragm 21 includes a first ring 211, a vibrating portion 212, and a second ring 213 sequentially connected from outside to inside, the first ring 211 has an outer fixing portion 2111, the outer fixing portion 2111 is fixed to the housing 1, the second ring 213 has an inner fixing portion 2131, and the inner fixing portion 2131 is fixed to the central magnetic portion 32. The first and second folding rings 211 and 213 are respectively disposed at both sides of the vibration part 212, so that the vibration stability of the vibration part 212 can be improved. The external fixing portion 2111 may be injection-molded or heat-pressed to be coupled to the housing 1, thereby improving coupling stability between the diaphragm 21 and the housing 1. Specifically, the inner voice coil 221 and the outer voice coil 222 are connected to the vibration portion 212.

In order to pursue miniaturization, thinning, etc. of the terminal equipment, the mounting space of the micro-speaker is increasingly reduced, and the rear cavity of the micro-speaker is consequently reduced, and in one embodiment, a rear cavity is formed among the housing of the micro-speaker, the magnetic circuit system, and the vibration system, and the volume Vb of the rear cavity is 1.5cm ³ or less. The improvement of the acoustic effect of the micro-speaker 100 of the present embodiment is particularly remarkable when the back volume of the micro-speaker is 1.5cm ³ or less, for example, 1.5cm³、1.4cm³、1.3cm³、1.2cm³、1.1cm³、1.0cm³、0.9cm³、0.8cm³、0.7cm³、0.6cm³、0.5cm³、0.4cm³ or the like. At this time, the vibration area of the diaphragm 21 is reduced, so that the sound pressure of the micro-speaker 100, especially the sound pressure in the middle-low frequency band, such as the sound pressure in the frequency bands of 30Hz-150Hz, 150Hz-500Hz, and 500Hz-5kHz, can be further improved, and the loudness and sensitivity of the micro-speaker 100 can be improved.

In one embodiment, the central magnetic portion 32 includes a central magnet 321 and a central magnetic conductive plate 322 sequentially stacked on the yoke 31; the inner magnetic part 33 includes an inner magnet 331 and an inner magnetic conductive plate 332 sequentially stacked on the yoke 31, the outer magnetic part 34 includes an outer magnet 341 and an outer magnetic conductive plate 342 sequentially stacked on the yoke 31, the center magnetic conductive plate 322 is disposed opposite to the inner magnetic conductive plate 332, and the inner magnetic conductive plate 332 is disposed opposite to the outer magnetic conductive plate 342. It can be understood that the center magnet 321 and the center magnetic conductive plate 322 are stacked on the magnetic yoke 31 along the vibration direction of the diaphragm 21, the inner magnet 331 and the inner magnetic conductive plate 332 are stacked on the magnetic yoke 31 along the vibration direction of the diaphragm 21, and the outer magnet 341 and the outer magnetic conductive plate 342 are stacked on the magnetic yoke 31 along the vibration direction of the diaphragm 21.

In this embodiment, the center magnet 321, the inner magnet 331 and the outer magnet 341 are magnetized along the vibration direction of the diaphragm 21, the magnetization directions of the center magnet 321 and the outer magnet 341 are the same, and the magnetization directions of the center magnet 321 and the inner magnet 331 are opposite. So arranged, the voice coil assembly 22 is forced to vibrate in the magnetic gap to drive the vibrating diaphragm 21 to vibrate and sound.

As a specific embodiment, as shown in fig. 3 to 7, an auxiliary magnet 323 is provided on a side of the central magnetically permeable plate 322 away from the central magnet 321, and the central magnet 321 and the auxiliary magnet 323 are magnetized in the vibration direction of the diaphragm 21, and the magnetization directions of the central magnet 321 and the auxiliary magnet 323 are opposite. The auxiliary magnet 323 is arranged on the central magnetic conductive plate 322, so that the magnetic induction line penetrating through the magnetic gap can be further increased, the magnetic field intensity is improved, the driving force of the magnetic circuit system 3 to the voice coil is improved, and the loudness and the sensitivity of the micro-speaker 100 are further improved. Alternatively, the auxiliary magnet 323 and the center magnet 321 are each N-pole at one end near the center magnetically permeable plate 322.

In the present embodiment, the inner fixing portion 2131 of the diaphragm 21 is fixed to the auxiliary magnet 323, and may be adhesively fixed. The first folding ring 211, the vibration part 212 and the second folding ring 213 of the diaphragm 21 may be an integrally formed structure, so as to improve the consistency of vibration of the diaphragm 21. Further, the auxiliary magnet 323 has an annular step 3231 at a side remote from the central magnetism guiding plate 322, and the inner fixing portion 2131 is fixed to the annular step 3231. So configured, firstly, the effective vibration area Sd of the diaphragm 21 can be reduced excessively; secondly, in the vibration direction of the diaphragm 21, a part of the second collar 213 is opposite to a part of the central magnetic portion 32, and the inner side of the vibration portion 212 is closer to the central magnetic portion 32, so that the assembly position of the inner voice coil 221 can be closer to the central magnetic portion 32, and the magnetic field strength of the magnetic gap can be ensured to the greatest extent without additionally increasing the gap between the central magnetic portion 32 and the inner magnetic portion 33.

In this embodiment, the magnetic circuit system 3 may also have different arrangements. For example, an auxiliary case (not shown) is provided on a side of the central magnetic plate 322 away from the central magnet 321, and the inner fixing portion 2131 is fixed to the auxiliary case, that is, the inner fixing portion 2131 is fixed to the central magnetic portion 32 through the auxiliary case.

The design of the utility model can improve the acoustic performance of medium and low frequency, and is specifically explained as follows:

at low frequencies, the effective sound pressure of the closed loudspeakers on the baffle at distance r is:

Wherein ω=2pi f;

Wherein ρ ₀ is air density, f is driving signal frequency, sd is effective radiation area of speaker, e _g is voltage, bl is driving force factor, re is product direct flow resistance, ω is angular frequency, cm is total force compliance;

Wherein, cms is the force of the loudspeaker, cas is the force of the rear cavity of the loudspeaker, and because the existing product is designed for a small rear cavity, cms is far greater than Cas, therefore,

Wherein Vb is the volume of the rear cavity of the loudspeaker, and C ₀ is the acoustic compliance of the loudspeaker; further, the processing unit is used for processing the data,

At this time, according to the above formula one, for the product of the small rear cavity of the present utility model, the diaphragm 21 adopts the double-folded-ring design including the first folded ring 211 and the second folded ring 213, so that Sd is reduced, and Sd is reduced to be able to raise the low-frequency sound pressure.

Further, in the design of the present utility model, the vibration system 2 includes a diaphragm 21 and a voice coil assembly 22 for driving the diaphragm 21 to vibrate, wherein the voice coil assembly 22 includes an inner voice coil 221 and an outer voice coil 222 disposed around the inner voice coil 221;

And, the magnetic circuit 3 includes a central magnetic portion 32, an inner magnetic portion 33 and an outer magnetic portion 34 disposed on the yoke 31 in parallel, the inner magnetic portion 33 is disposed around the central magnetic portion 32 and forms an inner magnetic gap therebetween, the outer magnetic portion 34 is disposed around the inner magnetic portion 33 and forms an outer magnetic gap therebetween, the inner voice coil 221 is disposed in the inner magnetic gap, and the outer voice coil 222 is disposed in the outer magnetic gap, thereby greatly improving the BL value of the micro-speaker 100.

According to the formula I, the BL is greatly improved on the basis of Sd reduction, so that the low-frequency performance of the product can be greatly improved.

At intermediate frequencies, the effective sound pressure of the closed loudspeakers on the baffle at distance r is:

wherein M is the vibration mass of the product.

According to the formula II, when the intermediate frequency is obtained, although the Sd of the loudspeaker is reduced, the BL lifting multiple is larger than the Sd reducing multiple, and the intermediate frequency can still be greatly improved.

Still further, the auxiliary magnet 323 is further added to the central magnetic portion 32, so that the BL of the product can be greatly improved. The middle-low frequency performance of the micro-speaker product can be further improved.

In conclusion, according to the scheme provided by the utility model, the product performance can be greatly improved in principle.

In one embodiment, the housing 1 has major and minor axis sides joined end to end, and the housing 1 is generally rectangular in configuration, rounded rectangular in configuration, etc., without limitation. The housing 1 may be further injection molded with conductive terminals to facilitate electrical connection of the voice coil assembly 22 to external circuitry.

In one embodiment, the voice coil assembly 22 has two opposite long sides, two opposite short sides, and a corner connecting the long sides and the short sides, which is understood as that the inner voice coil 221 has two opposite first long sides, two opposite first short sides, and a first corner connecting the first long sides and the first short sides, the outer voice coil 222 has two opposite second long sides and two opposite second short sides, and a second corner connecting the second long sides and the second short sides, the first long sides and the second long sides are opposite and form the long sides of the voice coil assembly 22 together, the first short sides and the second short sides are opposite and form the short sides of the voice coil assembly 22 together, and the first corner and the second corner form the corner of the voice coil assembly 22 together. The voice coil assembly 22 may be contoured to have a rounded rectangular shape, a racetrack shape, or the like. Further, the long side of the voice coil block 22 and the long side of the case 1 are disposed correspondingly, the short side of the voice coil block 22 and the short side of the case 1 are disposed correspondingly, and the corner of the voice coil block 22 and the corner of the case 1 are disposed correspondingly.

As shown in fig. 4, 8 and 9, in an embodiment, the micro-speaker 100 of the present utility model further includes an elastic support piece 23, where the elastic support piece 23 includes an inner connecting portion 231, an outer connecting portion 232, and a deformation portion 233 connecting the inner connecting portion 231 and the outer connecting portion 232, the inner connecting portion 231 is connected to the voice coil assembly 22, and the outer connecting portion 232 is connected to the housing 1. The elastic support piece 23 is connected with the voice coil assembly 22 and the shell 1, so that the voice coil assembly 22 is restrained from vibrating along the vibration direction, polarization, oblique vibration and the like are avoided, and the vibration stability of the vibration system 2 is improved.

The elastic support piece 23 includes a plurality of, and the elastic support piece 23 is located the voice coil assembly 22 and is kept away from one side of vibrating diaphragm 21, and the week side of voice coil assembly 22 is located at the interval, compares in the mode that elastic support piece 23 set up between voice coil assembly 22 and vibrating diaphragm 21, and elastic support piece 23 sets up in voice coil assembly 22 one end of keeping away from vibrating diaphragm 21, can further promote the centering force to voice coil assembly 22, promotes the vibration stability of voice coil assembly 22. Further, the magnetic circuit system 3 is provided with an avoidance gap for avoiding the elastic support piece 3.

Specifically, the inner connecting portion 231 includes a first connecting portion connected to the inner voice coil 221, a second connecting portion connected to the outer voice coil 222, and an intermediate portion connecting the first connecting portion and the second connecting portion, the inner magnetic portion 33 has a first avoiding gap 333 for avoiding the intermediate portion, the outer magnetic portion 34 has a second avoiding gap 343 for avoiding the deformation portion 233, and the first avoiding gap 333 and the second avoiding gap 343 are correspondingly communicated to form an avoiding gap. The inner connection portion 231 connects the inner voice coil 221 and the outer voice coil 222 at the same time, so that the vibration consistency of the voice coil assembly 22 is improved.

More specifically, the inner connecting portions 231 include four, the four inner connecting portions 231 are respectively disposed at corners of the voice coil assembly 22, the inner magnetic portion 33 includes four portions spaced apart from each other, and a first avoiding gap 333 is formed between two adjacent portions. Further, the width of the intermediate portion decreases and increases from the inner voice coil 221 to the outer voice coil 222, and the width of the first avoiding gap 333 decreases and increases from the inner voice coil 221 to the outer voice coil 222, and the outer shape of the inner magnetic portion 33 is substantially trapezoidal.

Correspondingly, the deformation parts 233 include four, the four deformation parts 233 are respectively disposed at corners of the voice coil assembly 22, the outer magnetic part 34 includes four parts spaced apart from each other, and a second avoiding gap 343 is formed between two adjacent parts. The second avoidance gap 343 is correspondingly communicated with the first avoidance gap 333 to form a avoidance gap.

In the above embodiment, the elastic support pieces 23 include four, and the four elastic support pieces 23 are provided at intervals at the corners of the voice coil assembly 22, that is, at the corners of the case 1, respectively. Or the elastic support pieces 23 include two, and the two elastic support pieces 23 are respectively arranged at two sides of the short side of the voice coil assembly 22, namely, at the short axis side of the housing 1.

In the above embodiment, the yoke 31 has the escape recess 312 for escaping the elastic leg 23. During the vibration of the elastic support piece 23, the avoiding recess 312 can further increase the lower vibration space of the elastic support piece 23. The relief recess 312 may be a recess or a through hole, etc., without limitation.

In one embodiment, the elastic support 23 includes four elastic support pieces, at least three elastic support pieces 23 are conductive support pieces, such as a flexible circuit board, and the inner voice coil 221 and the outer voice coil 222 are connected in series through the conductive support pieces and electrically connected to an external circuit.

Specifically, the bonding pad connected to the inner voice coil 221 is defined as a first bonding pad 231a, the bonding pad connected to the outer voice coil 222 is defined as a second bonding pad 231b, and the bonding pad connected to the external circuit is defined as a third bonding pad, and it is understood that the lead wire of the inner voice coil 221 is soldered to the first bonding pad 231a, and the lead wire of the outer voice coil 222 is soldered to the second bonding pad 231 b. A conductive support plate having a first pad 231a and a second pad 231b electrically connected to connect the inner voice coil 221 and the outer voice coil 222 in series; a conductive support plate is provided with a second bonding pad 231b and a third bonding pad which are electrically conducted and are used for electrically connecting the external voice coil 222 and an external circuit; an electrically conductive backing plate is provided with electrically conductive first and third pads 231a, for electrically connecting the inner voice coil 221 to external circuitry. The conductive path of the micro-speaker 100 may be: external circuit-third pad-second pad 231 b-external voice coil 222-second pad 231 b-first pad 231 a-internal voice coil 221-first pad 231 a-third pad-external circuit; or is: external circuit-third pad-first pad 231 a-internal voice coil 221-first pad 231 a-second pad 231 b-external voice coil 222-second pad 231 b-third pad-external circuit. Specifically, the first pad 231a and the second pad 231b are provided at the inner connection portion 231.

Further, when the conductive terminal is injection-molded on the housing 1, the third pad is electrically connected with the conductive terminal, and is electrically connected with an external circuit through the conductive terminal, so that the electrical connection of the voice coil assembly 22 to the external circuit is realized.

In the micro-speaker 100 of the present utility model, the first folder 211 is protruded toward the direction approaching the magnetic circuit 3, and the second folder 213 is protruded toward the direction departing from the magnetic circuit 3. The first ring 211 protrudes toward the direction close to the magnetic circuit 3, and after the micro-speaker 100 is combined with the housing of the acoustic device 200, the area of the sound emitting channel of the diaphragm 21 can be increased, which is beneficial to smooth radiation of sound waves to the outside. The second ring 213 is protruded towards the direction away from the magnetic circuit 3, so that the second ring 213 can be prevented from interfering with the central magnetic part 32 in the vibration process, and the reliability of the micro-speaker 100 is improved.

In an embodiment, the micro-speaker 100 of the present utility model further has a leakage hole, the leakage hole communicates with the internal space and the external space of the micro-speaker 100, and a ventilation spacer is provided to cover the leakage hole. The leakage hole may balance the air pressure difference between the inner space and the outer space of the micro speaker 100, improving the working stability thereof.

Alternatively, the leakage hole is provided between the housing 1 and the yoke 31, or provided on the yoke 31, or provided between the housing 1 and the yoke 31 and on the yoke 31 at the same time.

As a specific embodiment, the magnetic yoke 31 is plate-shaped, the housing 1 includes an annular frame 11 and a positioning post 12 provided at one end of the annular frame 11 and facing the magnetic yoke 31, the magnetic yoke 31 has a positioning recess 311 for positioning in cooperation, and positioning combination of the housing 1 and the magnetic yoke 31 is achieved by cooperation of the positioning post 12 and the positioning recess 311. At this time, a leakage hole is formed between the housing 1 and the yoke 31.

The utility model also proposes an acoustic device 200, the acoustic device 200 comprising a housing and the micro-speaker 100 described above, the micro-speaker 100 being arranged in the housing. The specific structure of the micro-speaker 100 refers to the structure of the micro-speaker 100 of the foregoing embodiment. Since the acoustic device 200 adopts all the technical solutions of all the foregoing embodiments, at least all the beneficial effects brought by the technical solutions of the foregoing embodiments are not described in detail herein.

The foregoing description of the embodiments of the present utility model should not be construed as limiting the scope of the utility model, but rather should be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the utility model as defined by the following description and drawings or as applied directly or indirectly to other related technical fields.

Claims

1. A micro loudspeaker is characterized by comprising a shell, a vibration system and a magnetic circuit system which are fixed on the shell,

The magnetic circuit system comprises a magnetic yoke, a central magnetic part, an inner magnetic part and an outer magnetic part which are arranged on the magnetic yoke at intervals, wherein the inner magnetic part is arranged around the central magnetic part and forms an inner magnetic gap between the inner magnetic part and the outer magnetic part, the outer magnetic part is arranged around the inner magnetic part and forms an outer magnetic gap between the inner magnetic part and the outer magnetic part,

The vibration system comprises a vibrating diaphragm and a voice coil assembly driving the vibrating diaphragm to vibrate, the voice coil assembly comprises an inner voice coil and an outer voice coil surrounding the inner voice coil, the inner voice coil is arranged in the inner magnetic gap, the outer voice coil is arranged in the outer magnetic gap, the vibrating diaphragm comprises a first folding ring, a vibrating part and a second folding ring which are sequentially connected from outside to inside, the first folding ring comprises an outer fixing part, the outer fixing part is fixed on the outer shell, the second folding ring comprises an inner fixing part, and the inner fixing part is fixed on the central magnetic part.

2. The micro-speaker of claim 1, wherein the center magnetic part comprises a center magnet and a center magnetic conductive plate sequentially stacked on the yoke, the inner magnetic part comprises an inner magnet and an inner magnetic conductive plate sequentially stacked on the yoke, the outer magnetic part comprises an outer magnet and an outer magnetic conductive plate sequentially stacked on the yoke, the inner magnetic gap is formed between the center magnetic conductive plate and the inner magnetic conductive plate, and the outer magnetic gap is formed between the inner magnetic conductive plate and the outer magnetic conductive plate.

3. The micro-speaker of claim 2, wherein the center magnet, the inner magnet, and the outer magnet are magnetized along a vibration direction of the diaphragm, the magnetization directions of the center magnet and the inner magnet are opposite, and the magnetization directions of the center magnet and the outer magnet are the same.

4. The micro-speaker of claim 1, further comprising an elastic support piece including an inner connection portion connected to the voice coil assembly, an outer connection portion connected to the housing, and a deformation portion connecting the inner connection portion and the outer connection portion.

5. The micro-speaker of claim 4, wherein the elastic support piece comprises a plurality of elastic support pieces, the plurality of elastic support pieces are arranged at one side of the voice coil assembly away from the vibrating diaphragm at intervals, and the magnetic circuit system is provided with an avoidance gap for avoiding the elastic support piece.

6. The micro-speaker of claim 5, wherein the inner connection part comprises a first connection part connected with the inner voice coil, a second connection part connected with the outer voice coil, and an intermediate part connecting the first connection part and the second connection part, the inner magnetic part has a first avoidance gap for avoiding the intermediate part, the outer magnetic part has a second avoidance gap for avoiding the deformation part, and the first avoidance gap and the second avoidance gap are correspondingly communicated to form the avoidance gap.

7. The micro-speaker of claim 5, wherein the elastic support pieces comprise four, and the four elastic support pieces are respectively disposed at four corners of the voice coil assembly;

Or the elastic support pieces comprise two, and the two elastic support pieces are respectively arranged on two opposite sides of the voice coil assembly.

8. The micro-speaker of claim 4, wherein the elastic support pieces include four, at least three of the four elastic support pieces are conductive support pieces, and the inner voice coil and the outer voice coil are connected in series through the conductive support pieces and electrically connected to an external circuit.

9. The micro-speaker of any one of claims 1 to 8, wherein the first collar is convex toward a direction closer to the magnetic circuit, and the second collar is convex toward a direction farther from the magnetic circuit.

10. An acoustic device comprising a housing and a micro-speaker according to any one of claims 1 to 9.