CN220915423U - Micro-speaker and acoustic device - Google Patents

Abstract

The utility model discloses a micro-speaker and an acoustic device, wherein the micro-speaker comprises a shell, a magnetic circuit system and a vibration system, wherein the magnetic circuit system and the vibration system are fixed on the shell, the magnetic circuit system comprises a magnetic yoke, a central magnetic assembly arranged on the magnetic yoke, two inner magnetic assemblies and two outer magnetic assemblies, the two inner magnetic assemblies are arranged between the two outer magnetic assemblies, and the central magnetic assembly is arranged between the two inner magnetic assemblies; the vibration system comprises a vibration film and a voice coil assembly, wherein the vibration film comprises an outer fixing part, a first folding ring, a vibration part, a second folding ring and an inner fixing part which are sequentially connected from outside to inside, the outer fixing part is fixed on a shell, the inner fixing part is fixed on a central magnetic assembly, the voice coil assembly comprises two voice coils, the two voice coils are all connected with the vibration part, each voice coil surrounds one inner magnetic assembly, the central magnetic assembly comprises a central magnet, a central magnetic guide plate and an auxiliary magnet, the central magnetic guide plate and the auxiliary magnet are sequentially overlapped in the vibration direction of the vibration film, and the auxiliary magnet and the central magnet are magnetized along the vibration direction of the vibration film and are opposite in magnetizing direction.

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 major indicator of the performance of micro-speakers, while the driving force factor BL value is a key factor affecting the sensitivity of the speaker. The existing loudspeaker magnetic circuit design has low central magnetic utilization rate, and BL is very difficult to lift under the condition that the product size is unchanged, so that the requirements of customers on tone quality cannot be met.

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 of the micro-speaker.

To achieve the above object, the present utility model provides a micro-speaker comprising

The magnetic circuit comprises a magnetic yoke, a central magnetic assembly, two inner magnetic assemblies and two outer magnetic assemblies, wherein the central magnetic assembly, the two inner magnetic assemblies and the two outer magnetic assemblies are alternately arranged on the magnetic yoke, the two inner magnetic assemblies are arranged between the two outer magnetic assemblies, the central magnetic assembly is arranged between the two inner magnetic assemblies, the two inner magnetic assemblies are symmetrically arranged relative to the central magnetic assembly, and the two outer magnetic assemblies are symmetrically arranged relative to the central magnetic assembly; the vibration system comprises a vibrating diaphragm and a voice coil assembly for driving the vibrating diaphragm to vibrate, the voice coil assembly comprises two voice coils, the two voice coils are connected with the vibrating diaphragm, and each voice coil is arranged around one inner magnetic assembly; wherein,

The center magnetic assembly comprises a center magnet, a center magnetic guide plate and an auxiliary magnet which are sequentially overlapped on the magnetic yoke along the vibration direction of the vibrating diaphragm, wherein the auxiliary magnet and the center magnet are magnetized along the vibration direction of the vibrating diaphragm and are opposite in magnetizing direction.

In an embodiment, the inner magnetic assembly comprises an inner magnet and an inner magnetic conductive plate which are sequentially overlapped on the magnetic yoke along the vibration direction of the vibrating diaphragm, the outer magnetic assembly comprises an outer magnet and an outer magnetic conductive plate which are sequentially overlapped on the magnetic yoke along the vibration direction of the vibrating diaphragm, the central magnetic conductive plate and the inner magnetic conductive plate are oppositely arranged, and the inner magnetic conductive plate and the outer magnetic conductive plate are oppositely arranged.

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

In an embodiment, the vibrating diaphragm includes an outer fixing portion, a first folding ring, a vibrating portion, a second folding ring and an inner fixing portion which are sequentially connected from outside to inside, wherein the outer fixing portion is fixed on the housing, and the inner fixing portion is fixed on the auxiliary magnet.

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.

In an embodiment, the voice coil is strip-shaped, the voice coil has two long sides and two short sides that end to end, the center magnetic assembly, the inner magnetic assembly, the outer magnetic assembly are arranged along the short side direction at intervals, the center magnetic assembly, the inner magnetic assembly, the outer magnetic assembly are strip-shaped, and the length direction of the center magnetic assembly, the inner magnetic assembly and the outer magnetic assembly is along the long side direction.

In one embodiment, the extended length of the central magnetic assembly and the extended length of the outer magnetic assembly are greater than the extended length of the inner magnetic assembly.

In one embodiment, the central magnetic assembly has an extension length that is greater than the extension length of the outer magnetic assembly and the extension length of the inner magnetic assembly.

In one embodiment, a width of the outer magnetic assembly along the short side direction is defined as a, a width of the inner magnetic assembly along the short side direction is defined as b, and a width of the central magnetic assembly along the short side direction is defined as c; wherein (a+1/2*c)/b is more than or equal to 0.8 and less than or equal to 1.2.

In one embodiment, the ratio of the length of the long side of the voice coil to the length of the short side of the voice coil is 3:1 to 7:1.

In one embodiment, the housing has a major axis side and a minor axis side connected end to end, the major axis side being parallel to the direction of the major axis side and the minor axis side being parallel to the direction of the minor axis side.

In an embodiment, the micro-speaker further includes a plurality of centering pieces, the centering pieces including a first fixing portion, a second fixing portion, and an elastic portion connecting the first fixing portion and the second fixing portion, the first fixing portion being connected to the voice coil, the second fixing portion being connected to the housing, the plurality of centering pieces being symmetrically disposed on two sides of a short side of the voice coil;

The miniature loudspeaker further comprises an auxiliary vibrating diaphragm, wherein the auxiliary vibrating diaphragm comprises an inner connecting part, a deformation part and an outer connecting part which are connected, the inner connecting part is connected with the voice coil, the outer connecting part is connected with the shell, the auxiliary vibrating diaphragm is multiple, and the auxiliary vibrating diaphragm is symmetrically arranged on two sides of the short sides of the voice coil.

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

According to the technical scheme of the miniature loudspeaker, the two outer magnetic assemblies, the two inner magnetic assemblies and the central magnetic assembly are arranged on the magnetic yoke in parallel, the central magnetic assembly is arranged between the inner magnetic assemblies, and the inner magnetic assemblies are arranged between the outer magnetic assemblies, namely, the central magnetic assembly is additionally arranged in the central area of the magnetic circuit system, so that the central area of the magnetic circuit system is fully utilized, and the magnetic field strength is improved under the condition that the size of a product is not increased. The two voice coils are further arranged to surround the inner magnetic assemblies respectively, so that the BL value of the micro-speaker is improved. Meanwhile, the central magnetic assembly comprises an auxiliary magnet and a central magnet with opposite magnetizing directions, so that the magnetic field strength is further enhanced, and the driving force of the magnetic circuit system is improved.

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 an exploded view of the micro-speaker of the present utility model;

FIG. 4 is a schematic top view of a micro-speaker of the present utility model;

FIG. 5 is a schematic cross-sectional view of a micro-speaker along line A-A of FIG. 4 in one embodiment;

FIG. 6 is a schematic cross-sectional view of a micro-speaker along line A-A of FIG. 4 in one embodiment;

FIG. 7 is a schematic diagram illustrating magnetizing directions of a magnetic circuit system according to an embodiment;

FIG. 8 is a schematic cross-sectional view of a micro-speaker along line A-A of FIG. 4 in one embodiment;

FIG. 9 is a schematic cross-sectional view of a micro-speaker along line A-A of FIG. 4 in one embodiment;

FIG. 10 is a schematic cross-sectional view of a micro-speaker along line A-A of FIG. 4 in one embodiment;

Fig. 11 is a schematic diagram showing the separation of the vibration system, the magnetic circuit system and the housing of the micro-speaker of fig. 9;

fig. 12 is an exploded schematic view of a magnetic circuit system of the micro speaker of fig. 9;

Fig. 13 is an exploded view of the magnetic circuit of the micro speaker of fig. 10;

Fig. 14 is a schematic structural view of a centering pad and an auxiliary diaphragm of the micro-speaker of the present utility model.

Reference numerals illustrate:

Reference numerals	Name of the name	Reference numerals	Name of the name
				100	Micro-speaker	22	Central magnetic assembly
1	Vibration system	221	Central magnet
				11	Vibrating diaphragm	2211	A first upper convex part
111	External fixing part	2212	First lower convex part
				112	First folding ring	222	Central magnetic conductive plate
113	Vibration part	2221	Raised portion
				114	Second folding ring	2222	First upper concave part
115	Internal fixing part	223	Auxiliary magnet
				12	Voice coil	23	Inner magnetic assembly
13	Connecting piece	231	Inner magnet
				14	Centering support piece	2311	A second upper convex part
141	First fixing part	2312	A second lower convex part
				142	Elastic part	232	Inner magnetic conductive plate
143	Second fixing part	2321	Second upper concave part
				15	Auxiliary vibrating diaphragm	24	External magnetic assembly
151	Inner connecting part	241	External magnet
				152	Deformation part	2411	Third lower convex part
153	External connection part	242	External magnetic conductive plate
				2	Magnetic circuit system	3	Outer casing
21	Magnetic yoke	31	First leakage hole
				211	First concave part	4	Breathable spacer
212	Second concave part	41	Bottom wall
				213	Third concave part	42	Side wall
214	Second leakage hole	200	Acoustic device

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.

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 major indicator of the performance of micro-speakers, while the driving force factor BL value is a key factor affecting the sensitivity of the speaker. The existing loudspeaker magnetic circuit design has low central magnetic utilization rate, and BL is very difficult to lift under the condition that the product size is unchanged, so that the requirements of customers on tone quality cannot be met.

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 14 in combination, in the embodiment of the present utility model, a micro-speaker 100 includes a housing 3, a vibration system 1 fixed to the housing 3, and a magnetic circuit 2, wherein the magnetic circuit 2 includes a yoke 21, a central magnetic assembly 22, two inner magnetic assemblies 23, and two outer magnetic assemblies 24 spaced apart from each other and arranged on the yoke 21, the two inner magnetic assemblies 23 are arranged between the two outer magnetic assemblies 24, and the central magnetic assembly 22 is arranged between the two inner magnetic assemblies 23; the vibration system 1 includes a diaphragm 11 and a voice coil 12 assembly for driving the diaphragm 11 to vibrate, the voice coil 12 assembly includes two voice coils 12, both voice coils 12 are connected with the diaphragm 11, and each voice coil 12 is disposed around an inner magnetic assembly 23.

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

The magnetic circuit system 2 comprises a magnetic yoke 21, two outer magnetic assemblies 24, two inner magnetic assemblies 23 and a central magnetic assembly 22 which are arranged on the magnetic yoke 21 in parallel, wherein the central magnetic assembly 22 is positioned between the inner magnetic assemblies 23, the inner magnetic assemblies 23 are positioned between the outer magnetic assemblies 24, and the outer magnetic assemblies 24 are connected with the shell 3 to fix the magnetic circuit system 2 and the shell 3. In the magnetic circuit system 2, a magnetic gap is formed around each inner magnetic assembly 23, two voice coils 12 are disposed corresponding to the two magnetic gaps, and each voice coil 12 is disposed around one inner magnetic assembly 23, i.e. each voice coil 12 is disposed corresponding to one magnetic gap. Compared with the conventional magnetic circuit loudspeaker, the utility model divides the middle magnetic circuit of the conventional loudspeaker into three parts, namely the central magnetic component 22 of the magnetic circuit system 2 and the inner magnetic components 23 positioned at two sides of the central magnetic component 22, so that a magnetic gap is formed between the central magnetic component 22 and the inner magnetic components 23 at two sides, the utilization rate of the magnet is improved, and the magnetic field intensity in the magnetic circuit system 2 is improved. In the micro-speaker 100 of the present utility model, the voice coil 12 assembly can use the magnetic field between the inner magnetic assembly 23 and the outer magnetic assembly 24, and also can use the magnetic field between the inner magnetic assembly 23 and the center magnetic assembly 22, 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.

Alternatively, the center magnet assembly 22, the inner magnet assembly 23 and the outer magnet assembly 24 are disposed at equal intervals, i.e., the interval between the inner magnet assembly 23 and the center magnet assembly 22 is equal to the interval between the inner magnet assembly 23 and the outer magnet assembly 24. The width of the magnetic gap surrounding each inner magnetic assembly 23 is ensured to be equal, and the vibration balance of the voice coil 12 is improved.

Optionally, the two inner magnetic assemblies 23 are symmetrically disposed about the central magnetic assembly 22, and the two outer magnetic assemblies 24 are symmetrically disposed about the central magnetic assembly 22, so that the magnetic field distribution is more uniform, and the vibration consistency of the two voice coils 12 is improved.

In one embodiment, as shown in fig. 5, the diaphragm 11 includes an outer fixing portion 111, a first ring 112, a vibrating portion 113, a second ring 114, and an inner fixing portion 115 sequentially connected from outside to inside, the outer fixing portion 111 is fixed to the housing 3, and the inner fixing portion 115 is fixed to the central magnetic assembly 22. The first and second bending rings 112 and 114 are respectively disposed at both sides of the vibration part 113, so that the vibration stability of the vibration part 113 can be improved. The outer fixing portion 111 may be injection-molded or heat-press-combined with the housing 3, thereby improving the combination stability between the diaphragm 11 and the housing 3. Specifically, both voice coils 12 are connected to the vibration part 113.

In one embodiment, the inner fixing portion 115 is elongated, and the width of the inner fixing portion 115 is smaller than the width of the central magnetic assembly 22, so configured, firstly, the effective vibration area Sd of the diaphragm 11 can be reduced too much; secondly, in the vibration direction of the diaphragm 11, a part of the second collar 114 is opposite to a part of the central magnetic assembly 22, the inner side of the vibration part 113 is closer to the central magnetic assembly 22, and then the assembly position of the voice coil 12 positioned on the inner side can be closer to the central magnetic assembly 22, so that the magnetic field strength of the magnetic gap can be ensured to the greatest extent without additionally increasing the gap between the central magnetic assembly 22 and the inner magnetic assembly 23.

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 assembly 22 includes a central magnet 221 and a central magnetic conductive plate 222 sequentially stacked on the yoke 21; the inner magnetic assembly 23 includes an inner magnet 231 and an inner magnetic conductive plate 232 sequentially stacked on the yoke 21, the outer magnetic assembly 24 includes an outer magnet 241 and an outer magnetic conductive plate 242 sequentially stacked on the yoke 21, the center magnetic conductive plate 222 is disposed opposite to the inner magnetic conductive plate 232, and the inner magnetic conductive plate 232 is disposed opposite to the outer magnetic conductive plate 242. It can be understood that the central magnet 221 and the central magnetic conductive plate 222 are stacked on the magnetic yoke 21 along the vibration direction of the diaphragm 11, the inner magnet 231 and the inner magnetic conductive plate 232 are stacked on the magnetic yoke 21 along the vibration direction of the diaphragm 11, and the outer magnet 241 and the outer magnetic conductive plate 242 are stacked on the magnetic yoke 21 along the vibration direction of the diaphragm 11.

In this embodiment, the center magnet 221, the inner magnet 231, and the outer magnet 241 are magnetized along the vibration direction of the diaphragm 11, the magnetization directions of the center magnet 221 and the outer magnet 241 are the same, and the magnetization directions of the center magnet 221 and the inner magnet 231 are opposite. So arranged, a magnetic gap is formed around each inner magnet 231, and the voice coil 12 is forced to vibrate in the magnetic gap to drive the vibrating diaphragm 11 to vibrate and sound.

As a specific embodiment, as shown in fig. 5 to 7, an auxiliary magnet 223 is disposed on a side of the central magnetically permeable plate 222 away from the central magnet 221, and the central magnet 221 and the auxiliary magnet 223 are magnetized in the vibration direction of the diaphragm 11, and the magnetization directions of the central magnet 221 and the auxiliary magnet 223 are opposite. By providing the auxiliary magnet 223 on the central magnetic conductive plate 222, the magnetic induction line passing through the magnetic gap can be further increased, the magnetic field strength is improved, the driving force of the magnetic circuit system 2 to the voice coil 12 is improved, and the loudness and sensitivity of the micro-speaker 100 are further improved. Specifically, the auxiliary magnet 223 and the center magnet 221 are each N-pole at one end near the center magnetically permeable plate 222.

In the present embodiment, the internal fixing portion 115 of the diaphragm 11 is fixed to the auxiliary magnet 223, and may be fixed by adhesion or the like. The outer fixing portion 111, the first ring 112, the vibrating portion 113, the second ring 114, and the inner fixing portion 115 of the diaphragm 11 may be an integrally formed structure, which improves the consistency of vibration of the diaphragm 11.

In this embodiment, the magnetic circuit system 2 may also have different arrangements. As shown in fig. 8 to 10, the central magnetically permeable plate 222 has a convex portion 2221 that is convex in a direction away from the yoke 21, and the inner fixing portion 115 is fixed to the convex portion 2221. While the diaphragm 11 is fixed, the use of components is reduced, and the cost and the assembly process are saved. Preferably, the boss 2221 is located in a middle region of the central magnetically permeable plate 222.

Of course, in other embodiments, the central magnetic conductive plate 222 may not have the protruding portion 2221, and an auxiliary case (not shown in the drawings) is provided on a side of the central magnetic conductive plate 222 away from the central magnet 221, and the inner fixing portion 115 is fixed to the auxiliary case, that is, the inner fixing portion 115 is fixed to the central magnetic assembly 22 through the auxiliary case.

As shown in fig. 9 to 13, in an embodiment, the central magnet 221 has a first upper protruding portion 2211 protruding toward a direction away from the yoke 21, and the central magnetically permeable plate 222 is provided with a first upper recessed portion 2222 corresponding to the first upper protruding portion 2211, and the first upper protruding portion 2211 is fittingly engaged with the first upper recessed portion 2222. The provision of the first upper protruding portion 2211 can effectively increase the size of the central magnet 221, and enhance the magnetizing rate of the central magnet 221. The central magnetically permeable plate 222 is correspondingly provided with a first upper recess 2222 that better cooperates with the central magnet 221 to guide the magnetic induction lines into the magnetic gap and to increase the magnetic field strength in the magnetic gap. Preferably, the first upper lobe 2211 is located in a middle region of the central magnet 221.

In an embodiment, the inner magnet 231 has a second upper protrusion 2311 protruding toward a direction away from the yoke 21, and the inner magnetic conductive plate 232 is provided with a second upper recess 2321 corresponding to the second upper protrusion 2311, and the second upper protrusion 2311 is fittingly coupled with the second upper recess 2321. The size of the inner magnet 231 can be effectively increased, and the magnetizing rate of the inner magnet 231 can be improved; the inner magnetic conductive plate 232 is provided with a first upper recess 2222, which can better cooperate with the second inner magnet 231 to guide the magnetic induction wire into the magnetic gap and increase the magnetic field intensity in the magnetic gap. Preferably, the second upper protrusion 2311 is located at a middle region of the inner magnet 231.

In an embodiment, the outer magnet 241 has a third upper protrusion protruding toward a direction away from the yoke 21, and the outer magnetic conductive plate 242 is provided with a third upper recess corresponding to the third upper protrusion, and the third upper protrusion is combined with the third upper recess in a matching manner. The size of the outer magnet 241 can be effectively increased, the magnetizing rate of the outer magnet 241 can be increased, and the magnetic field strength in the magnetic gap between the outer magnetically permeable plate 242 and the inner magnet 231 can be increased.

In this embodiment, in order to increase the magnetic field strength, the magnetic circuit system 2 may have other embodiments.

In one embodiment, the central magnet 221 has a first lower protruding portion 2212 protruding toward the direction approaching the yoke 21, and the yoke 21 is provided with a first lower recessed portion 211 corresponding to the first lower protruding portion 2212. Specifically, the first lower protruding portion 2212 is located in the middle region of the central magnet 221, and the first lower recessed portion 211 is formed by recessing the side of the yoke 21 facing the central magnet 221 toward the side facing away from the central magnet 221.

In one embodiment, the inner magnet 231 has a second lower protrusion 2312 protruding toward the direction approaching the yoke 21, and the yoke 21 is provided with a second lower recess 212 corresponding to the second lower protrusion 2312. Specifically, the second lower protrusion 2312 is located at the middle region of the inner magnet 231, and the second lower recess 212 is formed by recessing one side of the yoke 21 facing the inner magnet 231 toward the side facing away from the inner magnet 231.

In one embodiment, the outer magnet 241 has a third lower protrusion 2411 protruding toward the direction approaching the yoke 21, and the yoke 21 is provided with a third lower recess 213 fittingly engaged with the third lower protrusion 2411. Specifically, the third lower convex portion 2411 is provided at the outer edge region of the outer magnet 241, and the third lower concave portion 213 is formed by recessing the outer edge of the yoke 21 toward the inside of the accommodating space.

It should be noted that the above embodiments may be combined, for example, in another embodiment, the central magnet 221 has a first upper protruding portion 2211 protruding in a direction away from the yoke 21, the central magnetic conductive plate 222 is provided with a first upper recessed portion 2222 that is fittingly engaged with the first upper protruding portion 2211, the inner magnet 231 has a second upper protruding portion 2311 protruding in a direction away from the yoke 21, and the inner magnetic conductive plate 232 is provided with a second upper recessed portion 2321 that is fittingly engaged with the second upper protruding portion 2311. Or the center magnet 221 has a first lower protruding portion 2212 protruding toward the direction approaching the yoke 21, the inner magnet 231 has a second lower protruding portion 2312 protruding toward the direction approaching the yoke 21, and the yoke 21 is provided with a first lower recessed portion 211 corresponding to the first lower protruding portion 2212 and a second lower recessed portion 212 corresponding to the second lower protruding portion 2312. Or each magnet has a corresponding upper and lower protrusion, etc. Other embodiments are possible and are not listed here.

In the micro-speaker 100 of the present utility model, the voice coil 12 is long, the voice coil 12 has two long sides and two short sides connected end to end, the center magnetic assembly 22, the inner magnetic assembly 23, and the outer magnetic assembly 24 are arranged at intervals along the short sides, the center magnetic assembly 22, the inner magnetic assembly 23, and the outer magnetic assembly 24 are long, and the length direction thereof is along the long sides. The voice coil 12, the central magnetic assembly 22, the inner magnetic assembly 23 and the outer magnetic assembly 24 are all in long strips and have the same extending direction, so that the long side of the voice coil 12 is positioned in the magnetic gap, namely most of the voice coil 12 is utilized, the utilization rate of the voice coil 12 is improved, and the BL value of the micro-speaker 100 is further improved.

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 11 adopts the double-folded-ring design including the first folded ring 112 and the second folded ring 114, so that Sd is reduced, and Sd is reduced to be able to raise the low frequency.

Further, the design of the utility model is that the vibration system 1 comprises a vibrating diaphragm 11 and two voice coils 12 for driving the vibrating diaphragm 11 to vibrate;

And, the magnetic circuit system 2 includes two outer magnetic assemblies 24, two inner magnetic assemblies 23 and a central magnetic assembly 22 disposed on the magnetic yoke 21 in parallel, a magnetic gap is formed around each inner magnetic assembly 23, and each voice coil 12 is disposed around one inner magnetic assembly 23, so as to greatly increase 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 central magnetic assembly 22 further adds an auxiliary magnet 223, which can also greatly enhance the BL of the product. The middle-low frequency performance of the loudspeaker 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.

As a specific embodiment, the central magnet assembly 22 has an extension length greater than that of the inner magnet assembly 23, and the outer magnet assembly 24 has an extension length greater than that of the inner magnet assembly 23. The extended length of the center magnet assembly 22 and the outer magnet assembly 24 increases to raise the BL value when the magnetic field strength is raised. Alternatively, the extension length of the central magnetic assembly 22 is larger than the extension length of the outer magnetic assembly 24 and the extension length of the inner magnetic assembly 23, that is, the length of the central magnetic assembly 22 is longest, so that the external space of the micro-speaker 100 is fully utilized to maximize the size of the central magnetic assembly 22, further improve the magnetic field strength and improve the BL value.

In one embodiment, as shown in fig. 6, the width of the outer magnetic assembly in the short side direction is defined as a, the width of the inner magnetic assembly in the short side direction is defined as b, and the width of the center magnetic assembly in the short side direction is defined as c; wherein (a+1/2*c)/b is more than or equal to 0.8 and less than or equal to 1.2. Specifically, the value of (a+1/2*c)/b may be 0.8, 0.9, 1, 1.1, 1.2. The width of the inner magnetic assembly 23 is guaranteed, the utilization rate of the magnetic circuit system 2 is improved, and the magnetic field strength is improved.

Specifically, (a+1/2*c)/b is 1. I.e. the width of the inner magnet assembly 23 is equal to the sum of the width of the outer magnet assembly 24 and the width of the 1/2 central magnet assembly 22, i.e. a magnetic gap is formed between each inner magnet assembly 23 and the magnets of equal size, so that the utilization of the magnets can be maximized and the arrangement of the magnetic circuit system 2 optimized.

In one embodiment, the ratio of the length of the long side of the voice coil 12 to the length of the short side of the voice coil 12 is 3:1 to 7:1. by the arrangement, the length of the long side of the voice coil 12 can be increased, the utilization rate of the voice coil 12 to the magnetic field is increased, and the BL value is increased. Specifically, the ratio of the length of the long side to the length of the short side may be 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, etc., which is not limited herein.

In one embodiment, the housing 3 has a major axis side and a minor axis side connected end to end, the long side being parallel to the direction of the major axis side and the short side being parallel to the direction of the minor axis side. The shell 3 is matched with the vibration system 1 and the magnetic circuit system 2 to the greatest extent, so that the size of the shell 3 is saved, and the miniature design of the miniature loudspeaker 100 is facilitated.

As shown in fig. 3 and 14, in an embodiment of the present utility model, the micro speaker 100 further includes a centering support 14, where the centering support 14 includes a first fixing portion 141, a second fixing portion 143, and an elastic portion 142 connecting the first fixing portion 141 and the second fixing portion 143, the first fixing portion 141 is connected to the voice coil 12, and the second fixing portion 143 is connected to the housing 3. The centering support piece 14 is connected with the voice coil 12 and the shell 3, so that the voice coil 12 is restrained from vibrating along the vibration direction, polarization, oblique vibration and the like are avoided, and the vibration stability of the vibration system 1 is improved. Optionally, the centering support 14 is disposed on a side of the voice coil assembly away from the diaphragm 11, so as to improve the supporting and centering capability of the centering support 14 on the voice coil assembly.

Alternatively, the number of the centering support pieces 14 is two, and the two centering support pieces 14 are symmetrically arranged on two sides of the short side of the voice coil 12. Each centering support 14 has two first fixing portions 141, and each first fixing portion 141 is connected to a short side of one voice coil 12. Alternatively, the centering support 14 may be a plurality of centering support 14, such as four, and the plurality of centering support 14 may be symmetrically disposed.

In one embodiment, the centering support 14 is a conductive support, such as a flexible circuit board. The first fixing portion 141 of the spider 14 is provided with an inner pad, the second fixing portion 143 is provided with an outer pad, the elastic portion 142 is provided with a conductive line connecting the inner pad and the outer pad, and the two voice coils 12 are connected in series through the spider 14. Further, a conductive terminal is provided on the housing 3, an inner pad is connected to a lead wire of the voice coil 12, and an outer pad is connected to the conductive terminal, so that electrical connection of the voice coil 12 to an external circuit is achieved.

As shown in fig. 3 and 14, in an embodiment, the micro-speaker 100 further includes an auxiliary diaphragm 15, where the auxiliary diaphragm 15 includes an inner connecting portion 151, a deformation portion 152, and an outer connecting portion 153 connected to each other, the inner connecting portion 151 is connected to the voice coil 12, and the outer connecting portion 153 is connected to the housing 3. The auxiliary vibrating diaphragm 15 is connected with the voice coil 12 and the shell 3, so that the voice coil 12 is restrained from vibrating along the vibration direction, polarization, oblique vibration and the like are avoided, and the vibration stability of the vibration system 1 is improved. Optionally, the auxiliary diaphragm 15 is disposed on a side of the centering support 14 away from the voice coil assembly, so as to further enhance the centering capability of the voice coil assembly and avoid interference with the centering support 14.

Alternatively, two auxiliary diaphragms 15 are provided, and the two auxiliary diaphragms 15 are symmetrically disposed on two sides of the short side of the voice coil 12. Each auxiliary diaphragm 15 has two inner connecting portions 151, and each inner connecting portion 151 is connected to a short side of a voice coil 12. Or the auxiliary diaphragm 15 may be plural, for example, four, etc., and plural auxiliary diaphragms 15 are symmetrically disposed.

In one embodiment, the auxiliary diaphragm 15 is provided with a conductive layer, the conductive layer includes a first conductive layer disposed on the inner connecting portion 151, a second conductive layer disposed on the deformation portion 152, and a third conductive layer disposed on the outer connecting portion 153, the first conductive layer, the second conductive layer, and the third conductive layer are connected to form at least one conductive circuit, and the two voice coils 12 are connected in series through the conductive layers. Further, the housing 3 is provided with a conductive terminal, the first conductive layer is electrically connected to the lead wire of the voice coil 12, and the third conductive layer is electrically connected to the conductive terminal. The electrical connection of the voice coil 12 to an external circuit is achieved through the conductive layer.

Alternatively, the conductive layer is a conductive coating applied to the auxiliary diaphragm 15, or the conductive layer may be a combination of conductive materials and the auxiliary diaphragm 15, or the like. The leads and conductive layers of the voice coil 12 may be connected by conductive glue.

In the micro-speaker 100 of the present utility model, the first folder ring 112 is protruded toward the direction approaching the magnetic circuit 2, and the second folder ring 114 is protruded toward the direction away from the magnetic circuit 2. The first ring 112 protrudes toward the direction close to the magnetic circuit 2, and after the micro-speaker 100 is combined with the housing component of the acoustic device 200, the area of the sound emitting channel of the diaphragm 11 can be increased, which is beneficial to smoother radiation of sound waves to the outside. The second ring 114 is protruded towards the direction away from the magnetic circuit system 2, so that the second ring 114 can be prevented from interfering with the sound production of the central magnetic assembly 22 in the vibration process, and the reliability of the micro-speaker 100 is improved.

In one embodiment, a connecting piece 13 is disposed between the vibration portion 113 and the voice coil 12, and the connecting piece 13 connects the vibration portion 113 and the voice coil 12. The connection of the diaphragm 11 and the voice coil 12 by the connection member 13 can release the height design of the voice coil 12, making the size setting of the voice coil 12 more flexible. Alternatively, the connection member 13 includes two, and each voice coil 12 is connected to the vibration portion 113 through one connection member 13.

Alternatively, the connecting member 13 is a connecting coil, which is wound with an enameled wire. Preferably, the mass of the connection coil is smaller than that of the voice coil 12, and the vibration sensitivity of the diaphragm 11 is improved.

Alternatively, the connector 13 is made of carbon fiber or metal, and the vibration portion 113 is made of carbon fiber or metal, and the connector 13 is integrally formed with or separately formed from the vibration portion 113. The split molding can be specifically adhesive connection or welding connection. Optionally, the connecting piece 13 is a metal skeleton, the vibration part 113 is made of metal, the connecting piece 13 and the vibration part 113 are integrally formed, the connection strength of the voice coil 12 and the vibration part 113 is improved, and the connection reliability between the voice coil 12 and the vibration part 113 is improved.

In one embodiment, the micro-speaker 100 of the present utility model further has a leakage hole, which communicates with the internal space and the external space of the micro-speaker 100, and the ventilation spacer 4 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 3 and the yoke 21, or provided on the yoke 21, or provided between the housing 3 and the yoke 21 and on the yoke 21 at the same time.

As a specific embodiment, the yoke 21 is plate-shaped, the housing 3 includes an annular frame and a positioning protrusion provided at one end of the annular frame and facing the yoke 21, the yoke 21 has a positioning recess for positioning in cooperation, and positioning combination of the housing 3 and the yoke 21 is achieved by cooperation of the positioning protrusion and the positioning recess. At this time, a first leakage hole 31 is formed between the housing 3 and the yoke 21. Further, the yoke 21 is provided with a through hole communicating the magnetic gap and the external space, and the through hole serves as a second leakage hole 214. The air-permeable spacer 4 includes a side wall 42 covering the first leakage hole 31 and a bottom wall 41 covering the second leakage hole 214, the bottom wall 41 of the air-permeable spacer 4 being connected to the yoke 21, the side wall 42 being connected to the housing 3. With this arrangement, after the micro-speaker 100 is applied to the acoustic device 200, the external space of the micro-speaker 100 forms a rear cavity, the rear cavity can be filled with sound-absorbing particles, and the air-permeable spacer 4 does not occupy the volume of the rear cavity, so as to realize the maximum filling of the sound-absorbing particles, maximize the virtual volume of the rear cavity, thereby improving the acoustic performance of the acoustic device 200, and improving the suitability of the micro-speaker 100, and the micro-speaker 100 can be adapted to different acoustic devices 200.

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 (10)

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

The magnetic circuit system comprises a magnetic yoke, a central magnetic assembly, two inner magnetic assemblies and two outer magnetic assemblies, wherein the central magnetic assembly, the two inner magnetic assemblies and the two outer magnetic assemblies are arranged on the magnetic yoke at intervals, the central magnetic assembly is arranged between the two inner magnetic assemblies, the two inner magnetic assemblies are symmetrically arranged relative to the central magnetic assembly, and the two outer magnetic assemblies are symmetrically arranged relative to the central magnetic assembly;

The vibration system comprises a vibrating diaphragm and a voice coil assembly for driving the vibrating diaphragm to vibrate, the voice coil assembly comprises two voice coils, the two voice coils are connected with the vibrating diaphragm, and each voice coil is arranged around one inner magnetic assembly; wherein,

The center magnetic assembly comprises a center magnet, a center magnetic guide plate and an auxiliary magnet which are sequentially overlapped on the magnetic yoke along the vibration direction of the vibrating diaphragm, wherein the auxiliary magnet and the center magnet are magnetized along the vibration direction of the vibrating diaphragm and are opposite in magnetizing direction.

2. The micro-speaker of claim 1, wherein the inner magnetic assembly comprises an inner magnet and an inner magnetic conductive plate sequentially stacked on the yoke along the vibration direction of the diaphragm, the outer magnetic assembly comprises an outer magnet and an outer magnetic conductive plate sequentially stacked on the yoke along the vibration direction of the diaphragm, the center magnetic conductive plate is disposed opposite to the inner magnetic conductive plate, and the inner magnetic conductive plate is disposed opposite to 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, wherein the diaphragm comprises an outer fixing portion, a first folder ring, a vibrating portion, a second folder ring, and an inner fixing portion, which are sequentially connected from outside to inside, the outer fixing portion being fixed to the housing, and the inner fixing portion being fixed to the auxiliary magnet.

5. The micro-speaker of claim 4, 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.

6. The micro-speaker of any one of claims 1 to 5, wherein the voice coil is in a long strip shape, the voice coil has two long sides and two short sides connected end to end, the center magnetic assembly, the inner magnetic assembly, and the outer magnetic assembly are arranged at intervals along the short side direction, and the center magnetic assembly, the inner magnetic assembly, and the outer magnetic assembly are all in a long strip shape, and the length direction thereof is along the long side direction.

7. The micro-speaker of claim 6, wherein the extension length of the center magnetic assembly and the extension length of the outer magnetic assembly are greater than the extension length of the inner magnetic assembly;

And/or the extension length of the central magnetic component is greater than the extension length of the outer magnetic component and the extension length of the inner magnetic component;

And/or defining the width of the outer magnetic assembly along the short side direction as a, the width of the inner magnetic assembly along the short side direction as b, and the width of the central magnetic assembly along the short side direction as c; wherein (a+1/2*c)/b is more than or equal to 0.8 and less than or equal to 1.2.

8. The micro-speaker of claim 6, wherein,

The ratio of the length of the long side of the voice coil to the length of the short side of the voice coil is 3:1 to 7:1, a step of;

and/or the shell is provided with a long axis side and a short axis side which are connected end to end, the long axis side is parallel to the direction of the long axis side, and the short axis side is parallel to the direction of the short axis side.

9. The micro-speaker of claim 6, further comprising a plurality of centering tabs symmetrically disposed on both sides of a short side of the voice coil, wherein the centering tabs comprise a first fixing portion, a second fixing portion, and an elastic portion connecting the first fixing portion and the second fixing portion, the first fixing portion is connected to the voice coil, the second fixing portion is connected to the housing;

The miniature loudspeaker further comprises an auxiliary vibrating diaphragm, wherein the auxiliary vibrating diaphragm comprises an inner connecting part, a deformation part and an outer connecting part which are connected, the inner connecting part is connected with the voice coil, the outer connecting part is connected with the shell, the auxiliary vibrating diaphragm is multiple, and the auxiliary vibrating diaphragm is symmetrically arranged on two sides of the short sides of the voice coil.

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