CN112770236A

CN112770236A - Sound monomer

Info

Publication number: CN112770236A
Application number: CN202110143933.6A
Authority: CN
Inventors: 王苗苗; 郭晓冬
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2021-02-02
Filing date: 2021-02-02
Publication date: 2021-05-07
Also published as: WO2022166376A1

Abstract

The invention discloses a sound production monomer, which comprises a shell with an accommodating space, a magnetic conduction vibration diaphragm and two magnetic circuit systems, wherein the magnetic conduction vibration diaphragm and the two magnetic circuit systems are arranged in the accommodating space, a vibration space is formed between the two magnetic circuit systems, the magnetic conduction vibration diaphragm is arranged in the vibration space and is respectively arranged at intervals opposite to the two magnetic circuit systems, the magnetic conduction vibration diaphragm is used for vibrating and producing sound under the action of an alternating electromagnetic field generated by the magnetic circuit systems, a sound outlet is formed in the shell, the magnetic circuit systems comprise magnetic conduction cores which are arranged opposite to the sound outlet, and a plurality of pore structures which are used for communicating the sound outlet with the vibration space are formed in the magnetic conduction cores. The sounding monomer disclosed by the invention has a plurality of pore structures, so that ventilation structures such as through holes are prevented from being formed on components of a magnetic circuit system, the air flow balance is ensured, and the magnetism of the magnetic circuit system is improved.

Description

Sound monomer

Technical Field

The invention relates to the technical field of electroacoustic conversion, in particular to a sounding 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.

Disclosure of Invention

The invention mainly aims to provide a sounding monomer, and aims to solve at least one technical problem in the existing loudspeaker structure.

In order to achieve the above object, the sound-producing unit provided by the present invention includes a housing having an accommodating space, and a magnetic conductive diaphragm and two magnetic circuits disposed in the accommodating space, wherein a vibration space is formed between the two magnetic circuits, the magnetic conductive diaphragm is disposed in the vibration space and is respectively disposed opposite to the two magnetic circuits at an interval, the magnetic conductive diaphragm is configured to vibrate and produce sound under the action of an alternating electromagnetic field generated by the magnetic circuits, a sound outlet is formed in the housing, the magnetic circuits include magnetic conductive cores disposed opposite to the sound outlet, and a plurality of pore structures for communicating the sound outlet and the vibration space are formed in the magnetic conductive cores.

Optionally, the magnetic circuit system further includes a magnetic steel and a coil disposed around the magnetic steel, and the magnetically permeable core is disposed in the magnetic steel.

Optionally, an airflow channel is arranged in the magnetic steel, an opening at one end of the airflow channel is opposite to the magnetic-conductive vibrating diaphragm, the airflow channel is communicated with the sound outlet and the vibrating space, and the magnetic-conductive core is arranged in the airflow channel.

Optionally, the sound outlet, the magnetic steel, the magnetic core, the magnetic steel and the coil are coaxially arranged.

Optionally, the magnetically permeable core is foamed iron nickel.

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 steels of the two magnetic circuit systems are respectively attached to the top wall and the bottom wall, a first magnetic gap is formed between one magnetic steel and the first side wall, a second magnetic gap is formed between the other magnetic steel and the second side wall, and the coils of the two magnetic circuit systems are respectively arranged in the first magnetic gap and the second magnetic 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 magnetic conductive diaphragm is a planar magnetic conductive diaphragm.

The magnetic circuit system is arranged on the two sides of the magnetic conduction vibrating diaphragm, so that the magnetic circuit system can generate an alternating electromagnetic field by controlling the electrifying condition of the coil, 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 mass 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; through the magnetic circuit system with a plurality of pore structures, the magnetism of the magnetic circuit system is increased while smooth air flow circulation between the vibration space and the sound outlet is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings 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 a sounding unit according to an embodiment of the present invention;

FIG. 2 is a schematic view of a disassembled structure of a sounding unit according to an embodiment of the present invention;

FIG. 3 is a schematic view of a force analysis of a coil according to an embodiment of the present invention when the coil is not energized;

fig. 4 is a schematic view illustrating a force analysis of a coil energized according to an embodiment of the sound generating unit of the present invention.

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	2	Magnetic member
3	Magnetic conduction vibrating diaphragm	5	Magnetic circuit system
				51	Magnetic steel	52	Air flow channel
53	Coil	55	Magnetic conduction core

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

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all the directional indicators (such as up, down, 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 movement situation, etc. in a specific posture (as shown in the drawing), 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 implicitly 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, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

The invention provides a sounding single body 10.

Referring to fig. 1 and 2, the technical solution of the present invention provides a sound-producing unit 10, where the sound-producing unit 10 includes a casing 1 having an accommodating space, and a magnetic conductive diaphragm 3 and two magnetic circuits 5 which are disposed in the accommodating space, a vibration space is formed between the two magnetic circuits 5, the magnetic conductive diaphragm 3 is disposed in the vibration space and is respectively disposed opposite to the two magnetic circuits 5 at an interval, the magnetic conductive diaphragm 3 is configured to vibrate and produce sound under the action of an alternating electromagnetic field generated by the magnetic circuits 5, the casing 1 is provided with a sound outlet 12, the magnetic circuits 5 include a magnetic conductive core 55 which is disposed opposite to the sound outlet 12, and a plurality of pore structures which are formed in the magnetic conductive core 55 and used for communicating the sound outlet 12 with the vibration space.

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. Compared with the structure that the voice coil pushes the vibrating diaphragm to sound in the prior art, the voice coil connected with the magnetic-conductive vibrating diaphragm 3 is not arranged in the invention. The magnetic circuit systems 5 located on both sides of the magnetic diaphragm 3 generate an alternating electromagnetic field, and the magnetic diaphragm 3 directly moves along the connecting line direction of the two magnetic circuit systems 5 under the action of the alternating electromagnetic field, i.e., vibrates and produces sound in a vibration space formed between the two magnetic circuit systems 5. In the sounding process of the sounding unit 10, only the magnetic diaphragm 3 moves.

The magnetic conduction core 55 is provided with a plurality of pore structures, so that air flow can flow between the sound outlet 12 and the vibration space through the pore structures, which is beneficial to sound transmission generated by the magnetic conduction diaphragm 3 and air pressure balance in the accommodating space. Compared with the hollow ventilation channel reserved in the prior art, the magnetic conducting core forming the pore structure can have magnetism, so that the magnetic system 5 with the pore structure has higher magnetism than the magnetic system with the hollow ventilation channel in the magnetic systems with the same volume and materials.

In the invention, the magnetic circuit systems 5 are arranged on the two sides of the magnetic conduction vibrating diaphragm 3, so that the magnetic circuit systems 5 can generate an alternating electromagnetic field by controlling the electrifying 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 mass of a vibration part to be driven by the magnetic circuit systems 5 is small, the high-frequency performance can be improved, and the sound-electricity conversion efficiency can be improved; by arranging the magnetic circuit system 5 with a plurality of pore structures, the magnetism of the magnetic circuit system 5 is increased while the smooth air flow between the vibration space and the sound outlet 12 is ensured.

Optionally, the magnetic circuit system 5 further includes a magnetic steel 51 and a coil 53 disposed around the magnetic steel 51, the magnetically permeable core 55 is disposed in the magnetic steel 51, and the magnetic steel 51 is a permanent magnet. When the coils 53 on both sides of the magnetic diaphragm 3 are energized, the two magnetic circuits 5 interact with each other to generate an alternating electromagnetic field. 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 conductive diaphragm 3 are not energized, the magnetic conductive diaphragm 3 is only acted by the magnetic fields generated by the magnetic parts 2 on both sides, and at this time, the magnetic size, shape size and the like of the two magnetic parts 2 can be controlled, so that the magnetic conductive diaphragm 3 can be kept static at the preset position in the vibration space.

Compared with the arrangement mode that the coil 53 is arranged on the inner side of the magnetic part 2, the coil 53 is arranged around the magnetic part 2, so that when the coil 53 is electrified, in a magnetic field generated by the magnetic circuit system 5, the strength of a permanent magnetic field in a central area is higher than that of a permanent magnetic field in an edge area, the magnetic field strength of an alternating magnetic field sensed by the central area of the magnetic conduction vibrating diaphragm 3 is higher than that of the alternating magnetic field received by the edge area of the magnetic conduction vibrating diaphragm 3, therefore, the driving force received by the central area of the magnetic conduction vibrating diaphragm 3 is higher than that received by the edge area of the magnetic conduction vibrating diaphragm 3, and the magnetic conduction vibrating diaphragm 3 is more easily subjected to the action of the.

An airflow channel 52 is arranged in the magnetic steel 51, an opening at one end of the airflow channel 52 faces the magnetic conductive diaphragm 3, the airflow channel 52 is communicated with the sound outlet 12 and the vibration space, and the magnetic conductive core 55 is arranged in the airflow channel 52. In this embodiment, the magnetic steel 51 and the magnetic core 55 are respectively and independently disposed components, and the magnetic core 55 may be a magnetic material with a foam-like loose structure, such as foam iron nickel. In other embodiments, the magnetic steel 51 and the magnetic core 55 may also be an integrally formed structure.

In an embodiment, the sound outlet 12, the magnetic steel 51, the magnetic core 55 and the coil 53 are coaxially disposed, so as to facilitate the balance of the magnetic field strength in the formed alternating electromagnetic field along the coaxial direction, and facilitate the vibration balance of the magnetic core 55.

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 conduction diaphragm 3 is subject to a lower magnetic circuit systemThe magnetic flux of the system 5 is: 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 5₂', and the electromagnetic force F phi' received by the magnetic conductive diaphragm 3 is proportional to the magnetic flux change rate, i.e. F phi 'and Δ 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 circuit 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 circuit system 5 is disposed on the bottom wall 131 and forms a second gap with the second side wall 133, and the sound outlet 12 is opened on the bottom wall 131 and the top wall 111. Two coils 53 set up respectively in first clearance with in the second clearance, have outside to interior promptly, first lateral wall 113, a coil 53 and a magnet steel 51 overlap in proper order and establish, and second lateral wall 133, another coil 53 and another magnet steel 51 overlap in proper order and establish. 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.

In an embodiment, the magnetic conductive diaphragm 3 is a planar magnetic conductive diaphragm. Compared with the vibrating diaphragm with the corrugated rim structure in the prior art, the planar magnetic-conductive vibrating diaphragm 3 provided by the invention can reduce the size of the sound-producing unit 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 the magnetic conduction vibrating diaphragm 3 is 10-40 um, and the elastic modulus is more than 30 GPa.

The invention also provides an earphone which comprises the sounding monomer 10.

The specific structure of the sounding unit 10 refers to the above embodiments, and since the earphone adopts all technical solutions of all the above embodiments, at least all the beneficial effects brought by the technical solutions of the above embodiments are achieved, and no further description is given here.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The utility model provides a sound production monomer, its characterized in that, sound production monomer is including the casing that has accommodating space and locate accommodating space's magnetic conduction vibrating diaphragm and two magnetic circuit, two form the vibration space between the magnetic circuit, the magnetic conduction vibrating diaphragm is located in the vibration space and respectively with two the relative interval of magnetic circuit sets up, the magnetic conduction vibrating diaphragm is used for vibrating the sound production under the effect of the alternating electromagnetic field that magnetic circuit produced, the phonate hole has been seted up on the casing, magnetic circuit include with the phonate hole sets up the magnetic conduction core relatively, be formed with in the magnetic conduction core a plurality of be used for the intercommunication the phonate hole with the pore structure in vibration space.

2. The sound generating unit as claimed in claim 1, wherein the magnetic circuit system further comprises a magnetic steel and a coil disposed around the magnetic steel, and the magnetically conductive core is disposed in the magnetic steel.

3. The sounding unit according to claim 2, wherein an airflow channel is disposed in the magnetic steel, an opening at one end of the airflow channel faces the magnetic conductive diaphragm, the airflow channel communicates with the sound outlet and the vibration space, and the magnetic conductive core is disposed in the airflow channel.

4. The sound generating unit of claim 1, wherein the magnetically permeable core is foamed iron nickel.

5. The sound generating unit according to claim 2, wherein said sound outlet, said magnetic steel, said magnetic core and said coil are coaxially disposed.

6. The sounding unit as claimed in claim 2, 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.

7. The sounding unit according to claim 2, 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.

8. The sound generating unit of claim 7, 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 steels of the two magnetic circuit systems are respectively attached to the top wall and the bottom wall, a first magnetic gap is formed between one magnetic steel and the first side wall, a second magnetic gap is formed between the other magnetic steel and the second side wall, and the coils of the two magnetic circuit systems are respectively arranged in the first magnetic gap and the second magnetic gap.

9. The sound generating unit as claimed in claim 8, wherein the first sidewall and the second sidewall fix the magnetically conductive diaphragm from opposite sides of the magnetically conductive diaphragm, respectively.

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