WO2022217805A1 - Sound production device - Google Patents

Abstract

Disclosed is a sound production device, comprising sound-absorbing particles, a sound production unit, and a housing having an accommodating cavity, wherein the sound production unit is accommodated in the accommodating cavity, and the sound production unit divides the accommodating cavity into a front cavity and a rear cavity. The sound-absorbing particles are particles which can be attracted by a magnetic component, at least a portion of cavity walls forming the front cavity and/or the rear cavity in the housing have magnetism, and the sound-absorbing particles fill the front cavity and/or the rear cavity. There is a magnetic attraction force between the sound-absorbing particles under the action of a magnetic field of the cavity walls, and there is a magnetic attraction force between the sound-absorbing particles and the cavity walls. In the present invention, the sound-absorbing particles are used to achieve a virtual increase effect of a resonant space of an acoustic rear cavity of the sound production device, and free flow between the sound-absorbing particles is restricted by means of the cavity walls of the rear cavity having the magnetism, thereby reducing the collision and breakage of the sound-absorbing particles, and effectively protecting the acoustic performance of the sound production device.

Description

sound device technical field

The invention relates to the technical field of electro-acoustic conversion, in particular to a sound-emitting device.

Background technique

As an important acoustic component of portable electronic equipment, a sound-emitting device is used to complete the conversion between electrical signals and acoustic signals, and is an energy conversion device. In order to reduce the volume of the sound-emitting device, sound-absorbing particles are usually filled in the back cavity of the sound-emitting device to achieve a virtual increase in the resonance space of the acoustic rear cavity of the speaker. Friction and collision cause the sound-absorbing particles to break, and enter the speaker unit to cause pollution, resulting in the failure of acoustic performance.

Therefore, it is necessary to provide a new sound-generating device to solve the above-mentioned technical problems.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a sound-generating device, which aims to solve the problem that the sound-absorbing particles are easily broken, and the powder of the broken sound-absorbing particles enters the speaker unit to cause pollution and lead to the failure of its acoustic performance.

In order to achieve the above object, the present invention proposes a sound-generating device, wherein the sound-generating device comprises sound-absorbing particles, a sound-generating unit, and a casing having a cavity, the sound-generating unit is accommodated in the cavity, and the sound-generating unit is The single body divides the cavity into a front cavity and a rear cavity; the sound-absorbing particles are particles that can be attracted by magnetic components, and at least part of the cavity walls forming the front cavity and/or the rear cavity in the housing have magnetic properties , the sound-absorbing particles are filled in the front cavity and/or the rear cavity; the sound-absorbing particles are attracted to each other under the action of the magnetic field of the cavity wall, and are attracted by the cavity wall with magnetism.

Preferably, the housing comprises a magnetic part, a bottom wall and a plurality of side walls connected end to end, the bottom wall and a plurality of the side walls together enclose the front cavity and/or the rear cavity, the The magnetic element is arranged on the bottom wall and/or any one of the side walls.

Preferably, the number of the magnetic members is two, the two magnetic members are respectively disposed on two opposite side walls, and the opposite magnetic poles of the two magnetic members are opposite to each other.

Preferably, the magnetic member is one of NdFeB magnets, ferrite magnets, AlNiCo magnets, FeCrCo magnets, Samarium Cobalt magnets and rubber magnets.

Preferably, the thickness of the magnetic member is 0.1-2 mm.

Preferably, the magnetic member is attached or embedded on the side wall.

Preferably, the sound absorbing particles comprise a porous matrix and a ferromagnetic material.

Preferably, the porous matrix comprises at least one of zeolite, activated carbon, porous alumina, porous silica, hydrated aluminosilicate and metal organic framework material, and the particle size of the porous matrix is 0.1-80 μm.

Preferably, the ferromagnetic material comprises one or more of iron, cobalt, nickel and lanthanide rare earth metals, and/or one of oxides or compounds of iron, cobalt, nickel and lanthanide rare earth metals Or more, the particle size of the ferromagnetic material is 0.01-80 μm.

Preferably, in the sound-absorbing particles, the mass percentage of the porous base material is 50% to 96%; the mass percentage of the ferromagnetic material is 0.01% to 70%.

Preferably, the sound-absorbing particles further include an adhesive, and in the sound-absorbing particles, the weight percentage of the adhesive is 3% to 10%.

Preferably, the sound-absorbing particles further include an adhesive, and in the sound-absorbing particles, the particle size of the sound-absorbing particles is 100-600 μm.

Preferably, the sound-absorbing particles are also filled in the front cavity.

In the technical scheme of the present invention, the special physical pore structure inside the sound-absorbing particles is used to rapidly attract and desorb the gas in the back cavity, so as to realize the effect of virtual enlargement of the resonance space of the acoustic back cavity of the sound-emitting device, thereby effectively reducing the resonance frequency F0 during the sound-emitting period and increasing the low frequency. sensitivity. And by setting a cavity wall with a magnetic back cavity, a magnetic field is formed inside the back cavity, some of the sound-absorbing particles filled in the back cavity are directly attracted to the cavity wall of the back cavity, and the rest of the sound-absorbing particles close to the cavity wall are indirectly separated from the sound-absorbing particles. The sound-absorbing particles are attracted to the cavity wall, and the sound-absorbing particles are attracted to each other under the action of the magnetic field, which can limit the free flow between the sound-absorbing particles, avoid or even eliminate the friction and collision between the sound-absorbing particles, thereby eliminating the collision between the sound-absorbing particles. Flow noise, reduce the collision and breakage of sound-absorbing particles, and prevent the broken powder of sound-absorbing particles from entering the sound-emitting unit to cause pollution, effectively protecting the acoustic performance of the sound-emitting device.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

1 is a schematic structural diagram of a sound-emitting device in an embodiment of the present invention;

FIG. 2 is a table of reliability experimental data of the sound-absorbing particles filled in the sound-emitting device of the present invention.

Description of reference numbers:

label	name	label		name
100	sound device	31	back cavity
1	sound-absorbing particles	32	Magnetic parts
2	sounding unit	33	bottom wall
3	case	34	side wall

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relationship between various components under a certain posture (as shown in the accompanying drawings). The relative positional relationship, the movement situation, etc., if the sound of the specific gesture changes, the directional indication also changes accordingly.

In addition, descriptions such as "first", "second", etc. in the present invention are only for descriptive purposes, and should not be construed as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, "fixed" may be a fixed connection, a detachable connection, or an integrated; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be an internal communication between two elements or an interaction relationship between the two elements, unless otherwise explicitly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

The present invention provides a sounding device.

As shown in FIG. 1 , in an embodiment of the present invention, a sound-generating device 100 includes sound-absorbing particles 1 , a sound-generating unit 2 and a casing 3 with a cavity. The sound-generating unit 2 is accommodated in the cavity, and the The cavity is divided into a front cavity and a rear cavity 31 . The sound-absorbing particles 1 are particles that can be sound-absorbing by magnetic components, at least part of the cavity walls forming the front cavity and/or the rear cavity 31 in the housing 3 are magnetic, and the sound-absorbing particles 1 are filled in the front cavity and/or the rear cavity 31, The sound-absorbing particles 1 are attracted to each other under the action of the magnetic field of the cavity wall, and are attracted by the cavity wall with magnetism.

In the above embodiment, the special physical pore structure inside the sound-absorbing particles 1 is used to rapidly adsorb and desorb the gas in the back cavity 31 to achieve a virtual increase in the resonance space of the acoustic back cavity 31 of the sound-emitting device 100, thereby effectively reducing the 100 resonance frequency during sound production. F0, improve low frequency sensitivity. And by forming a magnetic cavity wall on at least part of the cavity wall of the rear cavity 31, and forming a magnetic field inside the rear cavity 31, the sound-absorbing particles 1 can be attracted by the magnetic cavity wall of the rear cavity 31. Due to the polarization of the magnetic cavity wall, The sound-absorbing particles 1 themselves are also magnetic and can attract each other. The sound-absorbing particles 1 are attracted to each other under the action of the magnetic field, and the sound-absorbing particles 1 are attracted by the magnetic cavity wall as a whole, so that the free flow between the sound-absorbing particles 1 can be restricted, and the friction and collision between the sound-absorbing particles 1 can be avoided or even eliminated. Thereby, the flow noise generated between the sound-absorbing particles 1 and the collision between the sound-absorbing particles and the cavity wall is eliminated, the collision and crushing of the sound-absorbing particles 1 is reduced, and the broken powder of the sound-absorbing particles 1 is prevented from entering the sound-emitting unit 2 to cause pollution, effectively protecting the sound-emitting device. 100 acoustic performance.

The sound-absorbing particles 1 are spherical in shape and 100-600 μm in diameter. The diameter of the sound-absorbing particles 1 matches the volume of the rear cavity 32, and the diameter of the sound-absorbing particles 1 is 100-600 μm, which is convenient for granulation and molding when manufacturing the sound-absorbing particles 1, and meets the filling rate requirements of the sound-absorbing particles 1 in the rear cavity 32.

In the embodiment shown in FIG. 1 , the sound-absorbing particles 1 are only filled in the rear cavity 31 . In another embodiment, the sound-absorbing particles 1 can also be filled only in the front cavity, and the sound-absorbing particles 1 in the front cavity are also in the front cavity. The cavity wall attracts each other under the action of the magnetic field, and is attracted by the magnetic front cavity wall. The sound-absorbing particles 1 are arranged in the front cavity to adjust the high-frequency performance of the sound-emitting device. Of course, the sound-absorbing particles 1 can be filled in the rear cavity 31 and the front cavity at the same time, so that the sound-absorbing particles 1 in the front cavity are attracted by the cavity wall of the front cavity, and the sound-absorbing particles 1 filled in the rear cavity 31 are attracted by the cavity wall of the rear cavity 31. Adjust both high and low frequency performance.

Specifically, the housing 3 includes a magnetic member 32 , a bottom wall 33 and a plurality of side walls 34 connected end to end. The bottom wall 33 and the plurality of side walls 34 together enclose a front cavity and/or a rear cavity 31 , and the magnetic member 32 is disposed in the bottom wall 33 and/or either side wall 34. The plurality of side walls 34 are connected to each other to form a cylindrical structure. One end of the cylindrical structure is connected to the chamber in which the sounding unit 2 is installed, and the other end is connected to the bottom wall 33 . The bottom wall 33 and the plurality of side walls 34 are on at least one of them. Magnetic members 32 are provided. By placing the magnetic member 32 on the bottom wall 33 or the side wall 34 , the sound-absorbing particles 1 are concentrated near the side wall 34 or the bottom wall 33 , so as to prevent the sound-absorbing particles 1 from being too close to the sound-generating unit 2 and prevent the acoustic performance of the entire sound-generating device 100 from being affected. influences. In this embodiment, the bottom wall 33 is a wall surface opposite to the air-permeable side of the sound generating unit 2 , and the side walls are other irregular wall surfaces.

In one embodiment, an isolation net can be set in the back cavity 31, and the sound-emitting unit 2 and the sound-absorbing particles 1 are arranged on opposite sides of the isolation net, thereby preventing the sound-absorbing particles 1 from entering the chamber where the sound-emitting unit 2 is installed, avoiding The acoustic performance of the entire sound-emitting device 100 is affected.

In a reliability verification experiment, two groups of sound-emitting devices were set up for reliability experiments, and the two groups of sound-emitting devices were operated at 70°C, voltage 3.18V, pink noise signal, and continuously energized for 144h. After the experiment, the resonant frequency F0 of the sound-emitting device was measured, the sound-absorbing particles were disassembled, and the phenomenon of breakage was observed. The difference between the two groups of sound-emitting devices is that the shell of one group of sound-emitting devices is not magnetic, that is, no magnetic field is formed in the rear cavity; the shell of the other group of sound-emitting devices is magnetic, that is, a magnetic field is formed in the rear cavity; please refer to Figure 2, p. The resonance frequency of a group of sound-emitting devices 100 before the reliability test is 792 Hz, and the resonance frequency after the reliability test is completed is 886 Hz. The removed sound-absorbing particles 1 are worn and partially damaged. The resonant frequency of the second group of sound-emitting devices before the reliability experiment was 791 Hz, and the resonant frequency after the reliability experiment was completed was 800 Hz, and the sound-absorbing particles removed did not change significantly. That is, the present invention provides a magnetic field by adding a magnetic member to the cavity wall of the rear cavity, and the sound-absorbing particles are attracted to the cavity wall under the action of magnetic attraction, which effectively limits the free flow between the sound-absorbing particles 1 and avoids or eliminates the sound-absorbing particles. The friction and collision between the sound-absorbing particles 1 can eliminate the flow noise caused by the collision between the sound-absorbing particles 1, reduce the phenomenon of the sound-absorbing particles 1 being broken due to the collision between the sound-absorbing particles 1, and the resonance frequency changes before and after the reliability test are small, which can effectively protect the sound. Acoustic performance of device 100 .

In order to improve the magnetic field strength, the number of the magnetic members 32 is two, the two magnetic members 32 are respectively disposed on two opposite side walls 34, and the opposite magnetic poles of the two magnetic members 32 are opposite to each other. That is, there is an attractive force between the two magnetic parts, so that the magnetic field formed between the two magnetic parts 32 is stable and uniform in intensity, which can avoid the phenomenon of mutual repulsion between the sound-absorbing particles 1, further restrict the free flow of the sound-absorbing particles 1, and eliminate the The sound-absorbing particles 1 are broken or surface changes caused by collision and friction are eliminated, and the failure problem of the sound-absorbing particles 1 caused by such changes is solved.

When the rear cavity 31 has an irregular spatial shape, the magnetic member 32 can be arranged on any two opposite side walls 34 on the cavity wall.

Specifically, the magnetic member 32 is one of NdFeB magnets, ferrite magnets, AlNiCo magnets, FeCrCo magnets, Samarium Cobalt magnets and rubber magnets. Different types of magnets can be selected according to the different needs of the magnetic field strength. In order to prevent the sound-absorbing particles 1 from colliding with the magnetic members 32 during the process of moving to the magnetic members 32 , a buffer layer may be provided on the outer side of the magnetic members 32 to further protect the integrity of the sound-absorbing particles 1 .

In a preferred embodiment, the magnetic member 32 is in the shape of a sheet, and the thickness of the magnetic member 32 is 0.1-2 mm. Therefore, while ensuring the strength of the magnetic field, the space occupied by the magnetic member 32 is reduced, the filling amount of the sound-absorbing particles 1 is ensured, and the effect of virtual increase of the resonance space of the acoustic rear cavity 31 of the speaker is realized, thereby effectively reducing the resonance frequency of the sound-emitting device 100 and improving the low frequency. sensitivity.

Of course, the pre-prepared magnetic member 32 can be attached or embedded on the side wall 34 . For example, the magnetic member 32 embedded in the side wall 34 is formed by an injection molding process. The magnetic member 32 may be exposed on the side wall 34 or completely sealed in the side wall 34 . In other embodiments, magnetic paint may also be coated on the cavity wall of the rear cavity 31 or a portion of the cavity wall corresponding to the housing 3 may be made of a material with magnetic properties.

In one embodiment, the sound-absorbing particles 1 are made by mixing a porous matrix and a ferromagnetic material. By uniformly mixing and connecting the porous matrix and the ferromagnetic material to form the sound-absorbing particles 1, and using the special physical pore structure inside the porous material to rapidly adsorb and desorb the gas in the rear cavity 31, the effect of virtual enlargement of the resonance space of the acoustic rear cavity 31 of the speaker is realized. , the sound-absorbing particles 1 can be attracted by the magnetic cavity wall by using the magnetic permeability of the ferromagnetic material. The porous matrix and the ferromagnetic material can be connected by an adhesive to form the sound-absorbing particles 1 . In other embodiments, other processing methods can also be used to connect the porous matrix and the ferromagnetic material, such as wrapping the porous matrix on the outside of the ferromagnetic material or wrapping the ferromagnetic material on the outside of the porous matrix.

When preparing the sound-absorbing particles 1, the porous material and the ferromagnetic material are uniformly dispersed in water according to a preset ratio to form a mixture; an adhesive is added to the mixture according to a preset ratio and stirred evenly to form a wet material; the wet material is made by a molding process A particle embryo body of uniform size is formed, and the particle ligand is dried to obtain the sound-absorbing particle 1. By doping the ferromagnetic material when preparing the sound-absorbing particles 1 , the prepared sound-absorbing particles 1 can be attracted by the cavity wall of the back cavity 31 , or can be attracted to each other under the action of the magnetic field of the back cavity 31 .

Specifically, the porous matrix includes at least one of zeolite, activated carbon, porous alumina, porous silica, hydrated aluminosilicate and metal organic framework materials, and the particle size of the porous matrix is 0.1-80 μm. Metal-organic framework materials are composed of metal ions and organic small molecule ligands to form porous materials with periodic network structure. The metal-organic framework materials have micropores and mesopores. The pore size of the micropores ranges from 0.3 to 0.8 nanometers. Pore diameters range from 2-40 nanometers. Wherein, the metal ions include at least one ion of copper, iron, zinc, manganese, indium, cadmium and cobalt; the small molecule ligands at least include at least one of formic acid, malonic acid, tartaric acid or citric acid.

Specifically, the ferromagnetic material includes one or more of iron, cobalt, nickel and lanthanide rare earth metals, and/or one or more of iron, cobalt, nickel and oxides or compounds of lanthanide rare earth metals The particle size of the ferromagnetic material is 0.01 to 80 μm. Selecting a similar range for the particle size of the porous and the particle size of the ferromagnetic material is to ensure the structural stability of the sound-absorbing particles 1 and the bonding strength between the raw materials of the sound-absorbing particles 1 . That is, ferromagnetic materials can be made of one or more ferromagnetic metal powders, or one or more ferromagnetic metal oxide powders, or a mixture of ferromagnetic metal powders and ferromagnetic metal oxide powders . In order to ensure that the sound-absorbing particles 1 are attracted under the action of magnetic force. The ferromagnetic material can specifically be selected from iron powder, nickel powder, cobalt powder, ferroferric oxide powder, ferrite powder, aluminum-cobalt-nickel alloy powder, neodymium-iron-boron powder, iron-chromium-cobalt alloy powder, samarium-cobalt alloy powder, and the like. The ferromagnetic material can be made of powder material. The porous matrix and the ferromagnetic material are uniformly mixed and connected to form sound-absorbing particles 1. The special physical pore structure inside the porous material is used to rapidly attract and desorb the gas in the back cavity to realize the acoustic back cavity of the speaker. Virtually increase the effect of resonance space. Of course, the ferromagnetic material can also be a monolithic material, and the sound-absorbing particles 1 are formed by covering the outer periphery of the ferromagnetic material with the porous matrix.

From the selection of the above materials, it can be seen that the ferromagnetic material in the sound-absorbing particle 1 can be a material such as iron powder that cannot generate magnetism itself, or can be a material that can generate magnetism such as NdFeB. Correspondingly, the formed sound-absorbing particle 1 itself It can be non-magnetic or magnetic, as long as it can be attracted by the magnetic cavity wall. For the sound-absorbing particles 1 that do not generate magnetism themselves, after being loaded into the front cavity and/or the rear cavity, they can be magnetized by the magnetic cavity wall to become the sound-absorbing particles 1 that can generate magnetism.

In addition, the sound-absorbing particles 1 also include an adhesive, and the adhesive is used for bonding the porous matrix and the ferromagnetic material. The porous matrix and the ferromagnetic material are bonded together by an adhesive to provide appropriate viscosity, which is convenient for the molding of the sound-absorbing particles 1, which is beneficial to improve the mechanical strength of the green body after molding, prevent the ferromagnetic material from separating from the porous matrix, and ensure sound absorption. Persistence of particle 1 magnetic properties. The adhesive can be one or more of polyacrylic, polyurethane and polyvinyl acetate adhesives. The mass percentage of the adhesive is 3% to 10%. In the case of ensuring that the porous matrix and the ferromagnetic material can be bonded together, during the preparation process, too much adhesive will block the voids on the porous matrix and control the adhesive. The amount of α is beneficial to control the size and number of pores in the magnetic sound-absorbing particles 1.

In the sound-absorbing particle 1, the mass percentage of the porous base material is 50%-96%, the mass percentage of the ferromagnetic material is 0.1%-70%, and the mass percentage of the adhesive is 3%-10%. In an embodiment, in the sound-absorbing particle 1, the mass percentage of the porous base material is 72%, the mass percentage of the ferromagnetic material is 20%, and the mass percentage of the adhesive is 8%. Balance the mass percentage of the porous substrate and the ferromagnetic material in the sound-absorbing particle 1, ensure the sound-absorbing ability of the sound-absorbing particle 1, control the sound-absorbing particle 1 to be tightly attracted by the magnetic cavity wall in the magnetic field, and ensure the porous The base material and the ferromagnetic material can be firmly bonded and not easily broken.

In one embodiment, in the sound-absorbing particle 1, the mass percentage of the porous base material is 50%, the mass percentage of the ferromagnetic material is 40%, and the mass percentage of the adhesive is 10%. By making the mass percentage of the ferromagnetic material as large as possible, it is ensured that the sound-absorbing particles 1 are attracted by the cavity wall or the sound-absorbing particles 1 under the action of the magnetic field formed by the cavity wall of the rear cavity 31 .

In an embodiment, in the sound-absorbing particle 1, the mass percentage of the porous base material is 94%, the mass percentage of the ferromagnetic material is 1%, and the mass percentage of the adhesive is 5%. When the volume of the rear cavity 31 is small, the mass percentage content of the porous substrate can be increased to enhance the effect of virtual enlargement of the resonance space of the rear cavity 31 of the speaker acoustics and effectively reduce the resonance frequency of the speaker.

When preparing the sound-absorbing particles 1, the porous material, the ferromagnetic material and the adhesive are mixed in a preset ratio to form a wet material;

Among them, the porous material and the ferromagnetic material can be uniformly dispersed in water at a fixed ratio to form a mixture; the adhesive is added to the mixture according to a preset ratio and stirred evenly to form a wet material; of course, the water can also be replaced with other solvents, Mixing the porous material and the ferromagnetic material first is beneficial to the uniform mixing of the porous material and the ferromagnetic material. Alternatively, the porous material and the ferromagnetic material are directly put into the adhesive aqueous solution for mixing and stirring to form a wet material.

Agglomeration granulation, extrusion granulation, spray granulation, etc. can be used to form particle embryos, and then the particle embryos with a particle size of 100-600 μm are screened and dried to obtain sound-absorbing particles 1 . The mixture can also be filled into a mold to form a particle body with a particle size of 100-600 μm, and the obtained particle body is dried to obtain the sound-absorbing particle 1 .

In one embodiment, the dried zeolite material and the ferric oxide material are added to the solvent water at a fixed ratio, and mechanically stirred for 1.5 h at 500 rpm to obtain a uniformly dispersed mixed suspension solution; polyacrylic acid adhesive is added to the mixture. The agent was mechanically stirred for 0.5h at 500rpm to form a wet mass. Wherein, the added mass of zeolite is 27% of the total mass of the above slurry; the added mass of ferric oxide material is 2.8% of the total mass of the above slurry; the added mass of polyurethane is 0.2% of the total mass of the above mixed suspension solution. In the slurry, the solid mass is 30% of the total mass of the above mixed suspension solution.

Add the uniformly dispersed wet material into the spray drying granulator, set the inlet temperature of the spray drying granulator to 140-160°C, the outlet temperature of 100-110°C, and the spray pressure of 0.5MPa, and dry and granulate to obtain preliminary shaped particles. .

The above-mentioned preliminary shaped particles were heated, cured and dried in an oven at 120° C. for 0.5 h to obtain dry particles. The above-mentioned dry particles are sieved with a mesh to obtain sound-absorbing particles 1 having a particle size of about 100 to 600 μm.

When preparing the sound-absorbing particles, by doping the ferromagnetic material when preparing the sound-absorbing particles, the prepared sound-absorbing particles can be attracted by the magnetic member attached to the rear cavity. The back cavity of the thus-produced sound-emitting device is filled with magnetic sound-absorbing particles, and the sound-absorbing particles can be attracted to each other under the action of magnetic force, thereby restricting the free flow between particles, avoiding or eliminating friction and collision between sound-absorbing particles, Thereby, the flow noise generated by the collision between the sound-absorbing particles is eliminated, and the phenomenon that the sound-absorbing particles are broken due to the collision between the sound-absorbing particles is reduced. In this way, the powder with broken sound-absorbing particles will not enter the sound-emitting unit to cause pollution, and the acoustic performance of the sound-emitting device will be effectively protected.

The above descriptions are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformations made by the contents of the description and drawings of the present invention, or the direct/indirect application Other related technical fields are included in the scope of patent protection of the present invention.

Claims (13)

1. A sound-generating device, characterized in that the sound-generating device comprises sound-absorbing particles, a sound-generating unit, and a housing having a cavity, the sound-generating unit is accommodated in the cavity, and the sound-generating unit stores the container. The cavity is divided into a front cavity and a rear cavity; the sound-absorbing particles are particles that can be attracted by magnetic components, and at least part of the cavity walls forming the front cavity and/or the rear cavity in the housing have magnetism, and the sound-absorbing particles fill in the front cavity and/or the rear cavity; the sound-absorbing particles are attracted to each other under the action of the magnetic field of the cavity wall, and are attracted by the cavity wall with magnetism.
2. The sound-emitting device according to claim 1, wherein the housing comprises a magnetic member, a bottom wall and a plurality of side walls connected end to end, the bottom wall and the plurality of side walls together enclose the front In the cavity and/or the rear cavity, the magnetic element is arranged on the bottom wall and/or any one of the side walls.
3. The sounding device according to claim 2, wherein the number of the magnetic parts is two, the two magnetic parts are respectively disposed on two opposite side walls, and the two magnetic parts have opposite magnetic poles Magnetic opposite.
4. The sound-emitting device according to claim 2, wherein the magnetic member is one of NdFeB magnets, ferrite magnets, AlNiCo magnets, FeCrCo magnets, Samarium Cobalt magnets and rubber magnets or variety.
5. The sound-emitting device according to claim 2, wherein the thickness of the magnetic member is 0.1-2 mm.
6. The sound-emitting device according to claim 2, wherein the magnetic member is attached to or embedded on the side wall.
7. The sound-emitting device according to any one of claims 1 to 6, wherein the sound-absorbing particles comprise a porous matrix and a ferromagnetic material.
8. The sound-emitting device of claim 7, wherein the porous matrix comprises at least one of zeolite, activated carbon, porous alumina, porous silica, hydrated aluminosilicates and metal organic framework materials, the The particle size of the porous matrix is 0.1 to 80 μm.
9. The sound-emitting device of claim 7, wherein the ferromagnetic material comprises one or more of iron, cobalt, nickel and lanthanide rare earth metals, and/or iron, cobalt, nickel and lanthanide One or more of oxides or compounds of rare earth metals, and the particle size of the ferromagnetic material is 0.01-80 μm.
10. The sound-emitting device according to claim 7, characterized in that, in the sound-absorbing particles, the mass percentage of the porous base material is 50% to 96%; the mass percentage of the ferromagnetic material is 0.01%～70%.
11. The sound-emitting device according to claim 7, wherein the sound-absorbing particles further comprise an adhesive, and the weight percentage of the adhesive in the sound-absorbing particles is 3% to 10%.
12. The sound-emitting device according to any one of claims 1 to 6, wherein the sound-absorbing particles have a particle size of 100-600um.
13. The sound-emitting device according to any one of claims 1 to 6, wherein the front cavity is filled with sound-absorbing particles.

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