CN214381368U

CN214381368U - Sound monomer

Info

Publication number: CN214381368U
Application number: CN202120300918.3U
Authority: CN
Inventors: 王苗苗; 李波波; 郭晓冬
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2021-02-02
Filing date: 2021-02-02
Publication date: 2021-10-08
Anticipated expiration: 2031-02-02
Also published as: WO2022166375A1

Abstract

The utility model discloses a sounding monomer, the sounding monomer includes the casing that has accommodating space, and locate accommodating space's magnetic conduction vibrating diaphragm and two magnetic circuit, two the magnetic circuit relative interval sets up, magnetic circuit includes the magnet steel of subsides setting on the casing and the coil of winding the magnet steel setting, the magnet steel is solid construction; the magnetic conduction vibrating diaphragm is arranged between the two magnetic circuits and is respectively arranged at intervals with the two magnetic circuits, and the magnetic conduction vibrating diaphragm is used for vibrating and sounding under the action of an alternating electromagnetic field generated by the magnetic circuits. The utility model discloses a set up the coil around the magnet steel for the central zone of magnetic conduction vibrating diaphragm produces bigger drive power, is favorable to the magnetic conduction vibrating diaphragm to produce the vibration.

Description

Sound monomer

Technical Field

The utility model relates to an electroacoustic conversion technology field, in particular to sound production monomer.

Background

Often need set up miniature speaker among the current electronic equipment, current miniature speaker is mostly through the voice coil loudspeaker voice coil circular telegram to make the voice coil loudspeaker voice coil move in the clearance, so that voice coil loudspeaker voice coil drive vibrating diaphragm vibration. Because the in-process of vibrating diaphragm vibration sound production, voice coil loudspeaker voice coil and vibrating diaphragm together move, lead to the vibration quality big, high frequency tone quality is not good, and electro-acoustic conversion efficiency is low.

Therefore, it is desirable to provide a novel sounding unit to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

The utility model mainly aims at providing a sound production monomer aims at solving at least one technical problem in the current speaker structure.

In order to achieve the above object, the sound generating unit provided by the present invention comprises a housing having an accommodating space, and a magnetic conductive diaphragm and two magnetic circuits disposed in the accommodating space, wherein the two magnetic circuits are disposed at a relative interval, the magnetic circuits comprise magnetic steel attached to the housing and a coil disposed around the magnetic steel, and the magnetic steel is of a solid structure; the magnetic conduction vibrating diaphragm is arranged between the two magnetic circuits and is respectively arranged at intervals with the two magnetic circuits, and the magnetic conduction vibrating diaphragm is used for vibrating and sounding under the action of an alternating electromagnetic field generated by the magnetic circuits.

Optionally, the magnetizing directions of the magnetic steels of the two magnetic circuit systems are the same, and the current directions of the coils of the two magnetic circuit systems are opposite.

Optionally, the housing includes a first magnetic yoke and a second magnetic yoke that cooperate to form the receiving space, the magnetic conductive diaphragm is disposed between the first magnetic yoke and the second magnetic yoke, and the two magnetic circuit systems are disposed in a space surrounded by the first magnetic yoke and the magnetic conductive diaphragm and a space surrounded by the second magnetic yoke and the magnetic conductive diaphragm, respectively.

Optionally, the first yoke comprises a top wall and a first side wall extending from the top wall, and the second yoke comprises a bottom wall and a second side wall extending from the bottom wall; the magnetic steel of one of the two magnetic circuit systems is arranged on the top wall and forms a first gap with the first side wall, the magnetic steel of the other magnetic circuit system is arranged on the bottom wall and forms a second gap with the second side wall, and the two coils are respectively arranged in the first gap and the second gap.

Optionally, the first side wall and the second side wall fix the magnetically conductive diaphragm from two opposite sides of the magnetically conductive diaphragm, respectively.

Optionally, the first magnetic yoke and/or the second magnetic yoke is provided with a sound outlet communicated with the accommodating space.

Optionally, an end of the first sidewall near the second sidewall is recessed to form the sound outlet.

Optionally, the sound outlet holes are formed in the bottom wall and the top wall, and the two sound outlet holes are respectively communicated with the first gap and the second gap. .

Optionally, the magnetic conductive diaphragm is a planar magnetic conductive diaphragm.

Optionally, the magnetic conductive diaphragm is a metal diaphragm.

The magnetic circuit system is arranged on the two sides of the magnetic conduction vibrating diaphragm, so that the energizing condition of the coil can be controlled, the magnetic circuit system generates an alternating electromagnetic field, the magnetic conduction vibrating diaphragm can vibrate in a vibration space under the action of the alternating electromagnetic field, a voice coil connected with the vibrating diaphragm is omitted, only the magnetic conduction vibrating diaphragm vibrates, the quality of a vibration part to be driven by the magnetic circuit system is small, the high-frequency performance can be improved, and the sound-electricity conversion efficiency can be improved; the utility model discloses a set up the coil around the magnet steel for the central zone of magnetic conduction vibrating diaphragm produces bigger drive power, is favorable to the magnetic conduction vibrating diaphragm to produce the vibration.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic cross-sectional view of an embodiment of the sound generating unit of the present invention;

fig. 2 is a schematic view of a disassembled structure of an embodiment of the sound-generating unit of the present invention;

FIG. 3 is a schematic view of the force analysis of the sounding unit according to the present invention under the condition that the coil is not energized;

fig. 4 is a schematic view illustrating a stress analysis under the condition that the coil of the sounding unit of the present invention is energized.

Examples reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Sound monomer	1	Shell body
11	First magnetic yoke	111	Roof wall
				113	First side wall	12	Sound outlet
13	Second magnetic yoke	131	Bottom wall
				133	Second side wall	3	Magnetic conduction vibrating diaphragm
5	Magnetic circuit system	51	Magnetic steel
				53	Coil

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit ly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides a sound production monomer 10.

Referring to fig. 1 and 2, the technical solution of the present invention provides a sound generating unit 10, where the sound generating unit 10 includes a housing 1 having an accommodating space, and a magnetic conductive diaphragm 3 and two magnetic circuits 5 disposed in the accommodating space, the two magnetic circuits 5 are disposed at a relative interval, the magnetic circuit 5 includes a magnetic steel 51 attached to the housing 1 and a coil 53 disposed around the magnetic steel 51, and the magnetic steel 51 is a solid structure; the magnetic conduction vibrating diaphragm 3 is arranged between the two magnetic circuits 5 and is respectively arranged at intervals with the two magnetic circuits 5, and the magnetic conduction vibrating diaphragm 3 is used for vibrating and sounding under the action of an alternating electromagnetic field generated by the magnetic circuits 5.

In the prior art, the voice coil is connected with the vibrating diaphragm, the voice coil is inserted into the magnetic gap, and after the voice coil is electrified, the voice coil reciprocates in the magnetic gap under the action of a magnetic field so as to push the vibrating diaphragm to vibrate. The utility model discloses with prior art in the structure difference of voice coil promotion vibrating diaphragm sound production lie in the utility model discloses in not set up the voice coil loudspeaker voice coil of being connected with magnetic conduction vibrating diaphragm 3, coil 53 sets up with the 3 intervals of magnetic conduction vibrating diaphragm. When the coils 53 on the two sides of the magnetic conduction diaphragm 3 are energized, the two magnetic circuit systems 5 generate an alternating electromagnetic field under the interaction, and the magnetic conduction diaphragm 3 directly moves along the connecting line direction of the two magnetic circuit systems 5 under the action of the alternating electromagnetic field, namely vibrates and produces sound in the vibration space formed between the two magnetic circuit systems 5. In the sounding process of the sounding unit 10, only the magnetic conductive diaphragm 3 moves, and the coil 53 and the magnetic steel 51 in the magnetic circuit system 5 can be stationary. When the coils 53 on both sides of the magnetic conduction diaphragm 3 are not powered on, the magnetic conduction diaphragm 3 is only under the action of the magnetic field generated by the magnetic steels 51 on both sides, and the magnetic size, shape and size and the like of the two magnetic steels 51 can be controlled at the moment, so that the magnetic conduction diaphragm 3 can be kept static at the preset position in the vibration space.

Compare in setting up the mode with coil 53 at magnet steel 51 inboard, the utility model discloses a set up coil 53 around magnet steel 51 for in the magnetic field that magnetic circuit 5 produced, central zone's permanent magnetic field intensity is bigger than in the regional permanent magnetic field intensity in border, when coil 53 circular telegram, the magnetic field intensity in alternating magnetic field that the central zone of magnetic conduction vibrating diaphragm 3 experienced is greater than the magnetic field intensity in alternating magnetic field that the border region of magnetic conduction vibrating diaphragm 3 received, consequently, the drive power that the central zone of magnetic conduction vibrating diaphragm 3 received is greater than the drive power that the border region of magnetic conduction vibrating diaphragm 3 received, so that magnetic conduction vibrating diaphragm 3 receives alternating electromagnetic field effect and sound production vibration more easily. In one embodiment, the magnetic steel 51, the coil 53 and the balancing diaphragm are coaxially arranged to facilitate vibration balancing.

In the utility model, the magnetic circuit system 5 is arranged on the two sides of the magnetic conduction vibrating diaphragm 3, so that the magnetic circuit system 5 can generate an alternating electromagnetic field by controlling the power-on condition of the coil 53, the magnetic conduction vibrating diaphragm 3 can vibrate in a vibration space under the action of the alternating electromagnetic field, and a voice coil connected with the vibrating diaphragm is omitted, so that only the magnetic conduction vibrating diaphragm 3 vibrates, the vibration part to be driven by the magnetic circuit system 5 has small quality, the high-frequency performance can be improved, and the sound-electricity conversion efficiency can be improved; the utility model discloses a set up coil 53 around magnet steel 51 for the drive power that the central zone of magnetic conduction vibrating diaphragm 3 produced is bigger, is favorable to magnetic conduction vibrating diaphragm 3 to produce the vibration.

Optionally, the magnetizing directions of the magnetic steels 51 of the two magnetic circuits 5 are the same, and the current directions of the coils 53 of the two magnetic circuits 5 are opposite.

Referring to fig. 3 and 4, fig. 3 is a force analysis diagram of the magnetically conductive diaphragm 3 in an embodiment when the coil 53 is not energized; fig. 4 is a force analysis diagram of the magnetically conductive diaphragm 3 in an embodiment when the coil 53 is energized. In the embodiment shown in fig. 3, the magnetic steel 51 located above the magnetic conductive diaphragm 3 and the magnetic steel 51 located below the magnetic conductive diaphragm 3 both have an N-pole upper end and an S-pole lower end, that is, the magnetization directions of the magnetic steel 51 are the same, and the direction shown by the magnetic induction line comes out from the N-pole and enters the S-pole, and meanwhile, the magnetic induction line is the direction shown by the arrow in the figure because the magnetic conductive diaphragm 3 has magnetic conductivity. Because the magnetic force direction that the magnetic conduction vibrating diaphragm 3 receives two magnet steels 51 is opposite, make the suspension that the magnetic conduction vibrating diaphragm 3 can be balanced between two magnet steels 51.

In the embodiment shown in fig. 4, the magnetic steel 51 located above the magnetic conductive diaphragm 3 and the magnetic steel 51 located below the magnetic conductive diaphragm 3 both have an N-pole upper end and an S-pole lower end, and the current directions of the coil 53 located outside the upper magnetic steel 51 are left-side in and right-side out, and the current directions of the coil 53 located outside the lower magnetic steel 51 are right-side in and left-side out, that is, the current directions of the two coils 53 are opposite. According to the ampere rule, the upper end of the coil 53 above the magnetic conductive diaphragm 3 is determined to be an S-pole, the lower end is determined to be an N-stage, the upper end of the coil 53 below the magnetic conductive diaphragm 3 is determined to be an N-pole, and the lower end of the coil is determined to be an S-stage.

The opposite two sides of the magnetic conduction vibrating diaphragm 3 are magnetized by the upper magnetic steel 51 and the lower magnetic steel 51 to generate polarity, the upper side of the magnetic conduction vibrating diaphragm 3 is an N pole, and the lower side is an S pole; the lower extreme of top coil 53 is that the upside homopolar repellent of N utmost point and magnetic conduction vibrating diaphragm 3, and the upper end of below coil 53 is that the downside opposite sex of N utmost point and magnetic conduction vibrating diaphragm 3 inhales mutually for magnetic conduction vibrating diaphragm 3 is under the effect of two superimposed forces, and downward deformation produces the vibration, thereby further improves this sound production monomer 10's electroacoustic conversion efficiency.

From another point of view, as shown in fig. 3, when the two coils are not energized, the magnetic flux in the magnetic conductive diaphragm is Φ a ═ Φ_g1+Φ_g2＝Φ_g+(-Φ_g) 0 is approximately distributed; wherein phi is_g1Magnetic flux, phi, generated by the upper magnet 51_g1Is defined as the positive direction, phi_g2The magnetic flux generated by the lower magnetic steel 51 is the same as the magnetic flux generated by the upper magnetic steel 51 in magnitude and opposite in direction, and the direction of the magnetic flux is a negative direction.

As shown in fig. 4, when the two coils are energized with reverse currents, the magnetic flux of the magnetic conductive diaphragm 3, which is subjected to the upper magnetic circuit system 5, is: phi is a₁＝φ_g1+φ_i1＝φ_g+(-φ_i) The direction of the magnetic flux generated by the current in the upper coil 53 is opposite to the direction of the magnetic flux generated by the upper magnetic steel 51, and is a negative direction.

The magnetic flux of the magnetic conduction diaphragm 3, which is subjected to the magnetic circuit system 5 below, is as follows: phi is a₂＝φ_g2+φ_i2＝(-φ_g)+(-φ_i) The direction of the magnetic flux generated by the current in the lower coil 53 is the same as the direction of the magnetic flux generated by the lower magnetic steel 51, and is a negative direction.

Therefore, the magnetic diaphragm 3 receives the magnetic flux φ of the upper magnetic circuit system 5₁Magnetic flux phi of lower magnetic circuit system 5 applied to magnetically permeable diaphragm 3₂。

When the two coils are energized with reverse currents, phi A' is equal to phi₁₊φ_2＝φ_g+(-φ_i)+(-φ_g)+(-φ_i)＝-2φ_iIf the power-on state is the last state, the power-off state is the initial state, and the magnetic flux variation in the magnetic conductive diaphragm 3 is: delta phi is phi A' -phi A is-2 phi_i-0＝-2φ_i。

The electromagnetic force F phi received by the magnetic conduction diaphragm 3 is in direct proportion to the change rate of the magnetic flux, namely F phi and delta phi/delta t are equal to-2 phi_i/. DELTA.t is proportional.

In the embodiment shown in fig. 4, the magnetic conductive diaphragm 3 is pushed by the electromagnetic force F phi to move closer to the lower magnetic circuit system 5. Similarly, when the current direction of the coil 53 above and below the magnetic conductive diaphragm 3 is opposite to that shown in fig. 4, the magnetic flux Φ of the upper magnetic circuit 5 received by the magnetic conductive diaphragm 3 can be known through the derivation process described above₁' > magnetic flux phi of the magnetic conductive diaphragm 3 under the magnetic circuit system 5₂And, a magnetically permeable diaphragm 3The electromagnetic force F phi ' is proportional to the magnetic flux change rate, i.e. F phi ' and delta phi '/[ delta ] t are 2 phi_i/. DELTA.t is proportional. The electromagnetic force generated by the magnetic circuit system 5 pushes the magnetic diaphragm 3 to move towards the upper magnetic circuit system 5, so that the magnetic diaphragm 3 can be controlled to vibrate and sound through controlling the current in the coil 53.

Referring to fig. 1 and 2 again, the housing 1 includes a first magnetic yoke 11 and a second magnetic yoke 13 that cooperate to form the accommodating space, the magnetic conductive diaphragm 3 is disposed between the first magnetic yoke 11 and the second magnetic yoke 13, and the two magnetic circuit systems 5 are respectively disposed in a space surrounded by the first magnetic yoke 11 and the magnetic conductive diaphragm 3 and a space surrounded by the second magnetic yoke 13 and the magnetic conductive diaphragm 3. First yoke 11 and second yoke 13 are magnetic conduction spare, and magnetic conduction vibrating diaphragm 3 directly contacts with the casing 1 of magnetic conduction, and the magnetic circuit is concentrated more, complete to make magnetic circuit 5's magnetic field can concentrate in casing 1, be favorable to promoting electroacoustic conversion efficiency.

Alternatively, the first yoke 11 includes a top wall 111 and a first side wall 113 extending from the top wall 111, and the second yoke 13 includes a bottom wall 131 and a second side wall 133 extending from the bottom wall 131; the magnetic steel 51 of one of the two magnetic systems 5 is disposed on the top wall 111 and forms a first gap with the first side wall 113, the magnetic steel 51 of the other magnetic system 5 is disposed on the bottom wall 131 and forms a second gap with the second side wall 133, the two coils 53 are respectively disposed in the first gap and the second gap, i.e., from outside to inside, the first side wall 113, one coil 53 and one magnetic steel 51 are sequentially sleeved, and the second side wall 133, the other coil 53 and the other magnetic steel 51 are sequentially sleeved. The magnetic steel 51 can be directly attached to the top wall 111 or the bottom wall 113, and the coil 53 can be wound on the magnetic steel 51, or can be wound in advance and then attached to the top wall 111 or the bottom wall 113. All parts of the magnetic circuit system 5 are sequentially sleeved, so that the size of the sounding single body 10 is effectively reduced.

Optionally, the first side wall 113 and the second side wall 133 fix the magnetic conductive diaphragm 3 from two opposite sides of the magnetic conductive diaphragm 3, that is, the edge of the magnetic conductive diaphragm 3 may be fixed at the end of the first side wall 113 or the second side wall 133 by gluing, welding, and the like, and then the first magnetic yoke 11 and the second magnetic yoke 13 are fixed by matching with the cover, so that other fixing structures are not required, and parts are fewer, thereby facilitating product assembly. Simultaneously because magnetic conduction vibrating diaphragm 3 is directly fixed through first yoke 11 and second yoke 13 for do not set up other fixed part between magnetic conduction vibrating diaphragm 3 and the magnetic circuit 5, the magnetic field distribution between magnetic conduction vibrating diaphragm 3 and the magnetic circuit 5 does not receive other fixed part influences, does not need independent part to support magnetic circuit 5, can reduce the clearance of magnetic conduction vibrating diaphragm 3 and magnetic circuit 5, is favorable to promoting the acoustoelectric conversion efficiency.

The first magnetic yoke 11 and/or the second magnetic yoke 13 are provided with sound outlet holes 12 communicated with the accommodating space, so that the airflow pushed by the magnetic conduction diaphragm 3 can be favorably spread to the outside. The person skilled in the art can open the sound outlet 12 communicating the accommodating space and the outside at different positions of the housing 1 according to the requirement. For example, the sound outlet 12 is opened on the first sidewall 113 and/or the second sidewall 133, and specifically, an end of the first sidewall 113 close to the second sidewall 133 is recessed to form the sound outlet 12. In another embodiment, the sound outlet holes 12 are opened on the bottom wall 131 and the top wall 111, and the two sound outlet holes 12 are respectively communicated with 12 the first gap and the second gap.

In an embodiment, the magnetic conductive diaphragm 3 is a planar magnetic conductive diaphragm or a metal diaphragm. Compare the vibrating diaphragm that has a roll over ring structure among the prior art, the utility model discloses in the plane magnetic conduction vibrating diaphragm 3 that provides can reduce the size of sound production monomer 10. Specifically, the magnetic conductive diaphragm 3 includes a metal main body, and the metal main body includes one or more of stainless steel S430, silicon steel, SPCC, iron-nickel alloy, iron-cobalt-vanadium alloy, and soft magnetic ferrite. Compared with a vibrating diaphragm made of rubber or paper, when the metal main body vibrates, the emitted tone quality has metal texture. The magnetic conduction vibrating diaphragm 3 can also comprise a damping layer arranged on the metal main body, and the damping layer can be a film layer, PEEK, TPU, TPEE and the like. Can adjust the damping nature of magnetic conduction vibrating diaphragm 3 through the damping layer, be favorable to the balance of the vibration of magnetic conduction vibrating diaphragm 3, bring more exquisite sense of hearing. In another embodiment, the magnetic conductive diaphragm 3 includes a substrate and a magnetic conductive layer disposed on the substrate, the substrate is any one of metal or nonmetal, elastomer or non-elastomer, and the magnetic conductive layer is made of powder with soft magnetic properties such as nickel, iron-nickel alloy, iron-phosphorus alloy, and is disposed on the substrate by plating, deposition, magnetron sputtering, and the like. The thickness of magnetic conduction vibrating diaphragm 3 is 10 ~ 40 um.

The above is only the preferred embodiment of the present invention, not so limiting the patent scope of the present invention, all of which are in the utility model discloses a conceive, utilize the equivalent structure transform that the content of the specification and the attached drawings did, or directly/indirectly use all to include in other relevant technical fields the patent protection scope of the present invention.

Claims

1. A sounding monomer is characterized by comprising a shell with an accommodating space, a magnetic conduction vibrating diaphragm and two magnetic circuit systems, wherein the magnetic conduction vibrating diaphragm and the two magnetic circuit systems are arranged in the accommodating space, the two magnetic circuit systems are arranged at intervals, each magnetic circuit system comprises a magnetic steel attached to the shell and a coil arranged around the magnetic steel, and the magnetic steel is of a solid structure; the magnetic conduction vibrating diaphragm is arranged between the two magnetic circuits and is respectively arranged at intervals with the two magnetic circuits, and the magnetic conduction vibrating diaphragm is used for vibrating and sounding under the action of an alternating electromagnetic field generated by the magnetic circuits.

2. The sounding unit as claimed in claim 1, wherein the magnetic steels of the two magnetic systems have the same magnetizing direction, and the coils of the two magnetic systems have opposite current directions.

3. The sounding unit according to claim 1, wherein the housing includes a first magnetic yoke and a second magnetic yoke that cooperate to form the receiving space, the magnetically conductive diaphragm is disposed between the first magnetic yoke and the second magnetic yoke, and the two magnetic circuit systems are disposed in a space surrounded by the first magnetic yoke and the magnetically conductive diaphragm and a space surrounded by the second magnetic yoke and the magnetically conductive diaphragm, respectively.

4. The sound generating unit of claim 3, wherein the first yoke includes a top wall and a first side wall extending from the top wall, and the second yoke includes a bottom wall and a second side wall extending from the bottom wall; the magnetic steel of one of the two magnetic circuit systems is arranged on the top wall and forms a first gap with the first side wall, the magnetic steel of the other magnetic circuit system is arranged on the bottom wall and forms a second gap with the second side wall, and the two coils are respectively arranged in the first gap and the second gap.

5. The sound generating unit as claimed in claim 4, wherein the first sidewall and the second sidewall fix the magnetically conductive diaphragm from opposite sides of the magnetically conductive diaphragm, respectively.

6. The sounding unit as claimed in claim 4, wherein the first yoke and/or the second yoke has a sound hole communicating with the receiving space.

7. The sound generating unit of claim 6, wherein the end of the first sidewall adjacent the second sidewall is recessed to form the sound outlet aperture.

8. The sound generating unit as claimed in claim 6, wherein the sound outlet holes are opened in the bottom wall and the top wall, and the two sound outlet holes are respectively communicated with the first gap and the second gap.

9. The sound generating unit as claimed in any one of claims 1 to 8, wherein the magnetically conductive diaphragm is a planar magnetically conductive diaphragm.

10. The sounding unit of any one of claims 1 to 8, wherein the magnetically permeable diaphragm is a metal diaphragm.