CN111147987B

CN111147987B - Sound-absorbing particle, sound-generating device, and electronic apparatus

Info

Publication number: CN111147987B
Application number: CN202010001822.7A
Authority: CN
Inventors: 潘泉泉; 姚阳阳; 牟雅静; 李春
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2020-01-02
Filing date: 2020-01-02
Publication date: 2022-01-07
Anticipated expiration: 2040-01-02
Also published as: WO2021135875A1; CN111147987A

Abstract

The invention discloses a sound-absorbing particle, a sound-producing device and an electronic device, comprising: activated carbon particles and a high molecular polymer binder mixed with the activated carbon particles; the activated carbon particles comprise an activated carbon particle inner core and a hydrophobic layer coated on the outer surface of the activated carbon particle inner core; the hydrophobic rate of the hydrophobic layer is more than 99%; the active carbon particle inner core comprises three elements of carbon, hydrogen and oxygen; the active carbon particle inner core comprises a disordered layer structure formed by randomly stacking molecular fragments of a two-dimensional graphite layer structure and/or a three-dimensional graphite microcrystal; the inner core of the activated carbon particle has a loose pore structure. The invention has the technical effects that the hydrophobic layer is arranged outside the inner core of the activated carbon particle, so that the moisture entering the inner core of the activated carbon particle can be reduced, and the sound absorption capability of the sound absorption particle is improved. The sound absorption particles are filled in the sound production device, so that the resonance frequency of the sound production device can be reduced, and the sound production performance of the sound production device can be improved.

Description

Sound-absorbing particle, sound-generating device, and electronic apparatus

Technical Field

The present invention relates to the field of acoustic technologies, and in particular, to a sound-absorbing particle, a sound-generating device, and an electronic apparatus.

Background

A sound generating device is a device used in an electronic apparatus to convert an electrical signal into a sound signal. The resonance frequency of the sound generating device is an important acoustic performance index, and the reduction of the resonance frequency of the sound generating device is beneficial to improving the acoustic effect of the sound generating device.

The resonant frequency refers to the frequency at which the sound generating device gradually increases from a low frequency range and the vibration intensity reaches the strongest vibration, or the frequency at which the impedance characteristic of the sound generating device is measured and the impedance value reaches the maximum value for the first time is called the resonant frequency or resonant frequency of the sound generating device, i.e. f 0.

How to reduce F0 of a sound generating device to improve the acoustic performance of the sound generating device is a problem to be solved in the art.

Disclosure of Invention

An object of the present invention is to provide a sound-absorbing particle, a sound-generating device, and a new technical solution of an electronic apparatus.

According to a first aspect of the present invention, there is provided a sound-absorbing particle comprising:

activated carbon particles and a high molecular polymer binder mixed with the activated carbon particles;

the activated carbon particles comprise an activated carbon particle inner core and a hydrophobic layer coated on the outer surface of the activated carbon particle inner core;

the hydrophobic rate of the hydrophobic layer is more than 99%;

the active carbon particle inner core comprises three elements of carbon, hydrogen and oxygen;

the active carbon particle inner core comprises a disordered layer structure formed by randomly stacking molecular fragments of a two-dimensional graphite layer structure and/or a three-dimensional graphite microcrystal;

the active carbon particle inner core has a loose pore canal structure.

Optionally, the activated carbon particles have a hydrophobicity of greater than 95%.

Optionally, the material of the hydrophobic layer comprises one of zeolite, aerogel, porous organic polymer.

Optionally, the pore structure comprises nano-scale micropores and mesopores.

Optionally, the pore size of the micropores ranges from 0.6nm to 1.3nm, and the pore size of the mesopores ranges from 2nm to 3.5 nm.

Optionally, the shape of the activated carbon particles comprises at least one of spherical, spheroidal, platelet, and rod shapes.

Optionally, the activated carbon particles have a particle size in the range of 0.1 μm to 100 μm.

Optionally, the sound absorbing particles are configured to have an adsorption amount of nitrogen gas of greater than or equal to 0.05 mmol/g.

According to a second aspect of the present invention, there is provided a sound emitting device comprising:

the device comprises a shell, a first fixing piece and a second fixing piece, wherein an accommodating cavity is formed in the shell;

the vibration assembly is arranged in the accommodating cavity and divides the accommodating cavity into a front sound cavity and a rear sound cavity;

the sound-absorbing particles as claimed in any one of the preceding claims, wherein the sound-absorbing particles are disposed within the rear acoustic cavity.

According to a third aspect of the present invention, there is provided an electronic device comprising the sound emitting apparatus described above.

According to an embodiment of the disclosure, the hydrophobic layer is arranged outside the activated carbon particle inner core, so that moisture entering the activated carbon particle inner core can be reduced, and the sound absorption capacity of the sound absorption particle is improved. The sound absorption particles are filled in the sound production device, so that the resonance frequency of the sound production device can be reduced, and the sound production performance of the sound production device can be improved.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a cross-sectional view of an activated carbon particle in one embodiment of the present disclosure.

Fig. 2 is a cross-sectional view of a sound-generating device to which sound-absorbing particles are applied in one embodiment of the present disclosure.

In the figure, 1 is a sound absorption particle, 11 is an activated carbon particle inner core, 12 is a hydrophobic layer, 2 is a shell, 21 is a front sound cavity, 22 is a rear sound cavity, and 3 is a vibration component.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

According to an embodiment of the present invention, there is provided a sound-absorbing particle, as shown in fig. 1, including: activated carbon particles and a high molecular polymer binder mixed with the activated carbon particles; the activated carbon particles comprise an activated carbon particle inner core and a hydrophobic layer 12 coated on the outer surface of the activated carbon particle inner core; the hydrophobic layer 12 has a hydrophobicity greater than 99%; the active carbon particle inner core 11 comprises three elements of carbon, hydrogen and oxygen; the active carbon particle inner core 11 comprises a disordered layer structure formed by randomly stacking molecular fragments of a two-dimensional graphite layer structure and/or a three-dimensional graphite microcrystal; the activated carbon particle core 11 has a loose pore structure.

In this embodiment, the sound-absorbing particle includes an activated carbon particle composed of an activated carbon particle core 11 and a hydrophobic layer 12 coated on an outer surface of the activated carbon particle core, and the activated carbon particle and a high molecular polymer binder are mixed together to form the sound-absorbing particle. The high molecular polymer adhesive has excellent performances of high adhesion, flexibility, water resistance, permeability resistance, crack resistance, aging resistance and the like. A large number of activated carbon particles can be firmly bonded together to form granules. The active carbon particles are in an amorphous structure, and the amorphous structure can improve the adaptability of the active carbon particles to different application scenes. For example, activated carbon sound absorbing particles can be used in different sound emitting devices. And the effect of reducing the resonance frequency F0 of the sound generating device can be achieved, and the medium and low frequency tone quality of the sound generating device can be improved. The effective volume of the sound cavity in the sound production device can be effectively enlarged through the absorption and release effects of the sound absorption particles on air.

The hydrophobic layer 12 has a hydrophobic rate of more than 99%, and the hydrophobic layer 12 with the hydrophobic rate can effectively prevent moisture from entering the activated carbon particle inner core 11, so that the water absorption of the activated carbon particles is reduced. So that the pore channel structure in the active carbon particle inner core 11 is not occupied by water molecules. The pore structure can adsorb the sound in the sound production device applied by the sound absorption particles, and reduce the resonance frequency of the sound production device.

For example, the activated carbon particle formed by the activated carbon particle core 1 coated with the hydrophobic layer 12 has a hydrophobicity ratio of more than 95% in the entire structure of the activated carbon particle. The activated carbon particles have excellent hydrophobic rate, and the water absorption rate of the activated carbon particles is further reduced. So that the pore channel structure in the active carbon particle inner core 11 is not occupied by water molecules. The pore structure can adsorb the sound in the sound production device applied by the sound absorption particles, and further reduces the resonant frequency of the sound production device.

The high molecular polymer adhesive has excellent adhesive property, and can aggregate a plurality of activated carbon particles together to form sound-absorbing particles. The sound-absorbing particles are formed to integrate the sound-absorbing function of the activated carbon particles, and a three-dimensional pore structure is formed in the sound-absorbing particles. The absorption and release capacity of the sound absorption particles to air can be improved.

For example, the activated carbon particles can be spherical, spheroidal, platelet, rod, and the like.

For example, the activated carbon particles in the shape of spheres, which are bonded together, are stacked to form macropores, and the macropores further improve the air absorption and release capacity of the sound absorption particles. The active carbon particles in the sheet shape can improve the structural stability of the active carbon sound-absorbing particles and reduce the risks of dusting and damage. Meanwhile, the carbonization process of the flake amorphous activated carbon particles is simple and convenient, and the cost is lower.

The preparation process of the sound-absorbing particles is simple, the manufacturing is easy to realize, the additional production cost is not increased, the mass manufacturing can be realized, and the sound-absorbing particles are suitable for large-batch industrial production.

In the present disclosure, the hydrophobic layer 12 coats the outer surface of the activated carbon particle core 11. The hydrophobic layer 12 has hydrophobicity, so that the active carbon particle inner core 11 can be effectively prevented from adsorbing a large amount of water, and the water absorption rate of the sound-absorbing particles is reduced. The influence of moisture entering the active carbon particle inner core 11 on the sound absorption effect of the sound absorption particles is avoided.

For example, the thickness of the water-repellent layer 12 may be 0.1 μm to 10 μm. Within this thickness range, the hydrophobic layer 12 can provide sufficient water-repellent ability, effectively avoiding the problem of the sound-absorbing ability of the sound-absorbing particles being reduced as a result of a large amount of moisture entering the activated carbon particle core 11. For example, moisture can be prevented from entering the transported pore structure in the activated carbon particle core 11. The loose pore structure can effectively achieve the sound absorption effect.

The water-repellent layer 12 has a thickness of, for example, 2 μm to 6 μm. The thickness of the hydrophobic layer 12 has a superior water-repellent ability within this thickness range, improving the ability to prevent moisture from entering the activated carbon particle core 11. The sound absorption reliability of the sound absorption particles is improved.

In one embodiment, the material of the hydrophobic layer 12 comprises one of zeolite, aerogel, porous organic polymer.

The materials of zeolite, aerogel and porous organic polymer have excellent waterproof performance, and do not influence the sound absorption performance of the sound absorption particles. For example, a hydrophobic layer of zeolite made of zeolite prevents a large amount of moisture from entering the sound-absorbing particles by the hydrophobic properties of the zeolite material. And an aerogel hydrophobic layer made using the aerogel, a porous organic polymer hydrophobic layer made using the porous organic polymer.

The thickness of the water-repellent layer 12 made of one of the above-described zeolite, aerogel and porous organic polymer is set to 0.1 μm to 10 μm. Alternatively, the thickness is set at 2 μm to 6 μm. The water absorption rate of the sound-absorbing particles can be effectively reduced, and the resonant frequency F0 of a sound-generating device to which the sound-absorbing particles are applied can be reduced.

For example, the hydrophobic layer 12 accounts for 1 to 50% by mass of the sound-absorbing particle, and the activated carbon particle core 11 accounts for 50 to 99% by mass of the sound-absorbing particle.

Specifically, the water-repellent layer 12 is made of one material of zeolite, aerogel, and porous organic polymer within the above-described set thickness range. And setting the mass percentage of the different materials in the sound-absorbing particles. The water absorption rate of the sound-absorbing particles and the resonance frequency F0 can be reduced to more preferable values. See in particular the contents shown in tables 1 to 3. Tables 1 to 3 show the water absorption rates of the sound-absorbing particles at the mass fraction and thickness of the hydrophobic layer 12 of different materials and the resonance frequency lowering effect of the sound-generating device to which the sound-absorbing particles are applied, which are obtained through experiments.

TABLE 1

Zeolite coating mass (wt%)	0	0.1～5	5～20	20～40	30～50
						Zeolite coating thickness (um)	0	0.1～2	2～4	2～6	4～10
F0 reducing effect (Hz)	170	165	160	158	150
						Water absorption (%)	35％	24％	16％	5％	2％

TABLE 2

TABLE 3

As can be seen from tables 1 to 3: when the hydrophobic layer 12 made of any one of zeolite, aerogel and porous organic polymer is coated outside the activated carbon particle core 11, the thickness of the hydrophobic layer 12 and the mass percentage of the hydrophobic layer 12 increase. The water absorption of the sound-absorbing particles is significantly reduced, and the resonance frequency F0 of the sound-generating device to which the sound-absorbing particles are applied is significantly reduced.

It can be seen that the sound-absorbing particles in the present disclosure are effective in reducing the water absorption rate, as well as in reducing the resonant frequency F0 of the sound-generating device to which the sound-absorbing particles are applied. The medium and low frequency performance of the sound generating device is improved.

In one embodiment, the activated carbon particles are at least one of spherical, spheroidal, platelet, and rod shaped.

The active carbon particles with different shapes are mixed together, so that the sound-absorbing particles with pore structures among the active carbon particles can be formed. The sound absorption performance of the sound absorption particles is increased.

For example, the sound-absorbing particles are made by mixing activated carbon particles of different shapes with a high molecular polymer binder. The sound-absorbing particles can be made in granular form. The sound production device has limited structural space, and the sound absorption particles are made into particles, so that the sound absorption particles are more easily filled in the limited space.

For example, the sound absorbing particles may be granular. May be a sound-absorbing particle comprising the sound-absorbing particle described above.

After the spherical carbon particles are bonded to form the sound absorption particles, more uniform and finer pore channel structures can be formed among the carbon particles, and the acoustic performance of the sound absorption particles is further improved. The adoption of the flake-shaped carbon particles can improve the structural stability of the sound-absorbing particles and reduce the risks of dusting and damage. Meanwhile, as the carbonization process of the flake amorphous activated carbon particles is simple and convenient and the cost is lower, the flake amorphous activated carbon particles are preferred from the industrial application perspective.

In the above example, the activated carbon particle core 11 includes three elements of carbon, hydrogen, and oxygen; among the three elements of carbon, hydrogen and oxygen in the activated carbon particle core 11, the carbon element accounts for the largest proportion, and the hydrogen element and the oxygen element only account for a small amount. The proportion of carbon element is increased, and the loose pore canal structure formed in the active carbon particle inner core 11 can be prevented from being too sparse. Thereby avoiding the pore diameter of the pore channel structure from becoming larger. The pore diameter of the pore channel structure is increased, so that the accumulated pore volume of the sound-absorbing particles is reduced, and the capacity of absorbing and air is reduced.

For example, the activated carbon particle core 11 includes a turbostratic structure formed by random packing of molecular fragments of a two-dimensional graphite layer structure and/or a three-dimensional graphite crystallite; the activated carbon particle core 11 has a loose pore structure.

A large number of irregular bonds are present on the edges of the two-dimensional graphite layer structure and the three-dimensional graphite crystallites. Irregular bonds can form tight connection between the two-dimensional graphite layer structure and the three-dimensional graphite microcrystal and form a pore channel structure by interweaving. The valence electrons of carbon have an sp2 hybrid orbital and an sp3 hybrid orbital, thereby forming a hexagonal carbon network plane. The active carbon particles formed by the random accumulation can form a fine and rich pore channel structure so as to meet the structural requirements of the sound-absorbing particles on the pore channel structure.

The two-dimensional graphite layer structure and/or the disordered layer structure formed by the random accumulation of the molecular fragments of the three-dimensional graphite microcrystals in the activated carbon particle core 11 mainly affect the pore structure formed in the material. The more the content of the two structures in the material is, after the material is subjected to the processing procedure of the carbonization process, the more uniform the pore structure is and the smaller the pore diameter of the pore structure is, so that the sound-absorbing particles can generate a good effect of reducing the resonant frequency.

In one embodiment, the channel structure includes nano-scale micro-and meso-pores.

The activated carbon particle core 11 has a large number of micropores and mesopores therein. The large number of micropores can increase the total accumulated pore volume of the particles on one hand and can improve the adsorption capacity of the activated carbon particles on air molecules on the other hand. A large number of micropores with small pore diameters can adsorb a large number of air molecules, so that the acoustic performance of the prepared sound-absorbing particles is improved. When air molecules need to be quickly sucked into or released from the micropores, the mesopores provide enough flowing space for the air molecules, so that the air molecules can be quickly moved, and the conditions of air blockage and micropores are reduced.

For example, the pore size of the micropores ranges from 0.6nm to 1.3nm, and the pore size of the mesopores ranges from 2nm to 3.5 nm.

Limiting the pore size of the micropores to the above-described pore size range enables the activated carbon particles to contain a sufficient number of micropores therein. The mesopores are within the pore size range, so that the performance of the whole particles for absorbing air, which is caused by reducing the accumulated pore volume of the activated carbon particles, can be prevented from being reduced. Therefore, the pore size ranges of the micropores and mesopores can improve the sound absorption performance of the sound absorption particles.

The inventor of the present invention verifies that the sound-absorbing particles of the present disclosure are filled in the rear sound cavity 22 of the sound-generating device, and the volume of the rear sound cavity 22 can be enlarged by N times by the absorption and release action of the sound-absorbing particles on air, which is equivalent to enlarging the volume of the rear sound cavity 22, where N is greater than 1. In the rear cavity 22 of the sound generating device, the forced vibration of the particles of sound-absorbing particles consumes the energy of the sound waves, which is equivalent to an increase in the air compliance in the volume of the rear cavity 22, thereby lowering the resonance frequency.

In one embodiment, the activated carbon particles have a particle size in the range of 0.1 μm to 100 μm.

By controlling the particle size of the activated carbon particle cores 11 and by controlling the particle size of the sound-absorbing particles, the effects of optimum bulk density and reduction of the resonance frequency can be achieved.

For example, the sound-absorbing particles are configured to have an adsorption amount of nitrogen gas of 0.05mmol/g or more. Thereby guarantee to inhale the sound granule and have sufficient absorption and desorption performance to the air to satisfy the needs in equivalent dilatation cavity space.

According to an embodiment of the present invention, there is provided a sound generating device, as shown in fig. 2, including: the device comprises a shell 2, wherein an accommodating cavity is formed in the shell 2; the vibration component 3 is arranged in the accommodating cavity and divides the accommodating cavity into a front sound cavity 21 and a rear sound cavity 22; as with the sound-absorbing particle 1 described above, the sound-absorbing particle 1 is disposed in the rear sound cavity 22.

In this embodiment, the sound-absorbing particles 1 may be granular. The sound-absorbing particles 1 are placed in a receiving cavity provided in the sound-generating device. The sound-absorbing particles 1 can be encapsulated in the accommodating cavity through the mesh cloth. Vibration subassembly 3 is arranged in the sound generating mechanism sound production, and at the in-process that vibration subassembly 3 takes place, holds the intracavity and inhale sound granule 1 and can realize adsorbing, the release effect to the interior gas that changes because of sound generating mechanism to reach increase back sound chamber 22 volume, reduce resonant frequency's effect.

The sound-absorbing particles 1 provided by the present disclosure can be applied to different types of sound-generating devices such as earphones, headphones, speakers, sound boxes, and the like. The sound absorption particles 1 are put into the rear sound cavity 22 of the sound generating device, which is equivalent to virtually enlarging the volume of the rear sound cavity 22 and also equivalent to increasing the damping of the sound generating device, so that the resonance intensity is reduced. Finally, the resonance frequency of the sound generating device can be reduced, and the effect of improving the acoustic performance of the sound generating device is achieved.

According to an embodiment of the present disclosure, an electronic device is provided, which includes the sound generating apparatus.

The sound generating device in the electronic equipment has the performance of reducing the resonance frequency of the sound generating device. The acoustic performance of the sound generating device in the electronic equipment is improved. The usability of the electronic equipment is improved. For example, the electronic device may be a cell phone, tablet computer, or other electronic device.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. An acoustical particle, comprising:

the active carbon particles comprise an active carbon particle inner core and a hydrophobic layer coated on the outer surface of the active carbon particle inner core, the hydrophobic layer is made of a material different from that of the active carbon particle inner core, and the hydrophobic layer is made of a material with hydrophobicity;

the material of the hydrophobic layer comprises one of zeolite, aerogel and porous organic polymer;

the hydrophobic rate of the hydrophobic layer is more than 99%;

the active carbon particle inner core has a loose pore canal structure.

2. The sound-absorbing particles according to claim 1, wherein the activated carbon particles have a hydrophobicity of more than 95%.

3. The sound-absorbing particle according to claim 1, wherein the pore structure includes nano-scale micro-pores and meso-pores.

4. The sound-absorbing particle according to claim 3, wherein the pore diameter of the micropores is in the range of 0.6nm to 1.3nm, and the pore diameter of the mesopores is in the range of 2nm to 3.5 nm.

5. The sound-absorbing particle according to claim 1, wherein the activated carbon particle has a shape including at least one of a sphere, a spheroidal shape, a sheet shape, and a rod shape.

6. The sound-absorbing particles according to claim 1, wherein the activated carbon particles have a particle size in the range of 0.1 μm to 100 μm.

7. The sound-absorbing particle according to claim 1, wherein the sound-absorbing particle is configured to have an adsorption amount of nitrogen gas of 0.05mmol/g or more.

8. A sound generating device, comprising:

the sound-absorbing particles of any one of claims 1-7, disposed within the rear acoustic cavity.

9. An electronic device characterized by comprising the sound emitting apparatus according to claim 8.