CN119277246A

CN119277246A - Sound absorbing components, sound generating devices and electronic equipment

Info

Publication number: CN119277246A
Application number: CN202411375107.4A
Authority: CN
Inventors: 李春; 潘泉泉; 凌风光; 王翠翠; 周树芝; 张成飞
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2024-09-29
Filing date: 2024-09-29
Publication date: 2025-01-07

Abstract

The present invention discloses a sound-absorbing component, a sound-generating device and an electronic device, and relates to the field of acoustics. The sound-absorbing component includes a shell and a molecular sieve powder filled in the shell. The shell is a flexible breathable material. The shell includes a main body and a cover part. The main body defines a storage space, and the molecular sieve powder is filled in the storage space. The cover part is covered on the main body to seal the storage space, wherein the main body is formed into a porous structure stacked by fiber filaments, the fiber filaments have a diameter of 0.05-10μm, the air permeability of the main body is 100-1000mm/s, and the average particle size of the molecular sieve powder is greater than 10μm. The present invention solves the technical problem that sound-absorbing particles are easily broken, resulting in broken powder contaminating the sound-generating monomer, and the molecular sieve powder does not need to be bonded and formed using an adhesive relative to the sound-absorbing particles, thereby eliminating the adhesive blocking the molecular sieve pores and affecting the sound absorption performance, and has better acoustic improvement performance.

Description

Sound-absorbing assembly, sound-producing device and electronic equipment

Technical Field

The invention relates to the field of acoustics, in particular to a sound absorption assembly, a sound generating device and electronic equipment.

Background

In recent years, under the trend of increasingly lighter and thinner electronic products, the space left for speakers is becoming smaller. Along with the flattening of the micro-speaker module, the cavity volume of the acoustic rear cavity is reduced. In order to solve the problem of low-frequency performance reduction of the loudspeaker caused by space reduction, sound-absorbing particles made of porous materials can be filled into the rear acoustic cavity, and the effect of virtual increase of the resonant space of the acoustic rear cavity of the loudspeaker is realized by utilizing the rapid adsorption-desorption property of special physical pore channel structures in the porous materials to the rear cavity gas, so that the resonant frequency F0 of the loudspeaker is effectively reduced, and the low-frequency sensitivity is improved.

At present, the average particle size of sound-absorbing particles filled in a rear cavity of a loudspeaker is 300-400 mu m, the filling volume of the sound-absorbing particles is up to about 80% of the total volume of the rear cavity, and when the sound-absorbing particles are piled up, a gap space exists, the volume of the rear cavity cannot be effectively filled, so that the acoustic improvement effect is reduced, the adhesive molding particles are required to be added in the process of manufacturing the sound-absorbing particles, the adhesive can block part of pore channels of the molecular sieve raw powder, further loss of acoustic performance is caused, the sound-absorbing particles move in the rear cavity to collide, and the problems of crushing and powder pollution to sounding monomers are easy to occur.

Disclosure of Invention

The invention mainly aims to provide a sound absorption assembly, a sound production device and electronic equipment, and aims to solve the technical problem that sound absorption particles filled in a rear cavity of an existing loudspeaker are easy to break, so that sound production monomers are polluted.

In order to achieve the above object, the present invention provides a sound absorbing assembly, including a housing and molecular sieve powder filled in the housing, the housing being a flexible air permeable material, the housing including a main body portion and a cover portion, the main body portion defining an accommodating space, the molecular sieve powder being filled in the accommodating space, the cover portion being covered on the main body portion to seal the accommodating space, wherein the main body portion is formed into a porous structure formed by stacking fiber filaments, the fiber filaments have a filament diameter of 0.05-10 μm, the air permeability of 100-1000mm/s, and the molecular sieve powder has an average particle diameter of more than 10 μm.

In one embodiment, the fiber filaments comprise at least one of chemical fibers, modified chemical fibers, and natural fibers;

And/or the fiber filaments have a melting point greater than 100 ℃.

In one embodiment, the body portion has an areal density of 15-550g/m ²;

And/or the thickness of the main body part is 0.05-4mm.

In one embodiment, the body portion has an acoustic absorption coefficient greater than 0.3.

In one embodiment, the ratio of pore volume of micropores to pore volume of mesopores in the molecular sieve powder is greater than 0.5.

In an embodiment, the volume of the molecular sieve powder is greater than 50% of the volume of the accommodation space.

In an embodiment, the cover part is a double sided tape, a hot melt adhesive film, a plastic film or the same material as the main body part.

In one embodiment, the body portion and the cover portion are connected by means of heat fusion encapsulation or gluing.

The invention also provides a sound production device which comprises a sound production monomer, a shell and an inner cavity surrounded by the shell and the sound production monomer, wherein the sound absorption component is filled in the inner cavity.

In one embodiment, the housing comprises a first shell and a second shell which are oppositely arranged, and the sound absorbing assembly is clamped between the first shell and the second shell;

or, an adhesive layer is arranged on the inner wall of the shell, and the adhesive layer is in adhesive connection with the sound absorbing component.

The invention also provides an electronic device comprising a sound emitting arrangement as described above.

The invention provides a sound absorption assembly, a sound production device and electronic equipment, wherein the sound absorption assembly comprises a shell and molecular sieve powder filled in the shell, the shell is made of flexible breathable materials, the shell comprises a main body part and a sealing cover part, the main body part defines an accommodating space, the molecular sieve powder is filled in the accommodating space, the sealing cover part is covered on the main body part to seal the accommodating space, the main body part is formed into a porous structure formed by stacking fiber filaments, the filament diameter of the fiber filaments is 0.05-10 mu m, the air permeability of the main body part is 100-1000mm/s, and the average particle size of the molecular sieve powder is larger than 10 mu m. The shell of the sound absorbing component adopts flexible ventilation materials, the main body part of the porous structure can enable rear cavity gas to smoothly enter and exit while containing molecular sieve powder, the sound absorbing component has certain acoustic performance, the filament diameter of fiber filaments is 0.05-10 mu m, the ventilation rate of the main body part is 100-1000mm/s, so that the main body part structure can maintain good ventilation performance while intercepting the molecular sieve powder, the problem of powder leakage pollution is avoided, the average grain diameter of the molecular sieve powder is larger than 10 mu m, the grain diameter of the molecular sieve powder is larger than that of a common molecular sieve powder material, the structural arrangement of the interior of the molecular sieve powder is more compact, more pore structure units can be contained in unit volume, in addition, the molecular sieve powder is bonded and molded relative to sound absorbing particles without using adhesives, and therefore the problem that the blocking of the molecular sieve is influenced by the adhesives in the sound absorbing particles can be solved, and the sound absorbing component has better acoustic improvement performance.

Drawings

In order to more clearly illustrate the embodiments of the present drawings or the technical solutions in the related art, the drawings that are required to be used in the embodiments or the related technical descriptions will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present drawings, and other drawings may be obtained according to the structures shown in the drawings without inventive efforts to those of ordinary skill in the art.

Fig. 1 is a cross-sectional view of one embodiment of a sound absorbing assembly in accordance with the present invention;

fig. 2 is a cross-sectional view of another embodiment of a sound absorbing assembly according to the present invention using an adhesive connection;

FIG. 3 is a cross-sectional view of an embodiment of a sound emitting device according to the present invention;

Fig. 4 is a cross-sectional view of another embodiment of a sound emitting device according to the present invention.

Reference numerals illustrate:

100. 110, sounding monomer;

120. A housing 121, a first housing 122, a second housing;

130. the sound-absorbing component comprises a sound-absorbing component, a shell, 131a, a main body part, 131b, a sealing cover part, 132, molecular sieve powder, 133 and an adhesive layer;

140. A posterior acoustic cavity.

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

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, the following description of the embodiments accompanied with the accompanying drawings will be given in detail. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, the sound absorbing assembly 130 includes a housing 131 and a molecular sieve powder 132 filled in the housing 131, the housing 131 is made of a flexible air-permeable material, the housing 131 includes a main body 131a and a cover 131b, the main body 131a defines a containing space, the molecular sieve powder 132 is filled in the containing space, and the cover 131b covers the main body 131a to seal the containing space, wherein the main body 131a is formed into a porous structure formed by stacking fiber filaments, the filament diameter of the fiber filaments is 0.05-10 μm, the air permeability of the main body 131a is 100-1000mm/s, and the average particle size of the molecular sieve powder 132 is greater than 10 μm.

In this embodiment, the shell 131 is made of a flexible air-permeable material, and the flexible shell 131 can well wrap the molecular sieve powder 132 therein, so that good air permeability ensures the permeability of the rear cavity gas. The body 131a is formed in a porous structure formed by stacking filaments, and the filament diameter of the filaments has a certain influence on the pore diameter and air permeability of the porous structure of the body 131 a.

Specifically, the present embodiment controls the filament diameter of the filament within a range of 0.05 to 10. Mu.m, for example, 0.05. Mu.m, 0.1. Mu.m, 0.5. Mu.m, 1. Mu.m, 3. Mu.m, 5. Mu.m, 7. Mu.m, 10. Mu.m, etc. The smaller the filament diameter of the fiber filament, the thinner the thickness of the formed body portion 131a can be, and a better air permeability can be obtained, whereas when the filament diameter exceeds 10 μm, the larger the pore diameter is formed, the larger the air permeability is, and the powder is not easily intercepted. The minimum value of the wire diameter in this example can be 0.05. Mu.m, and a film excellent in thickness and air permeability can be formed for the main body 131a.

The air permeability of the main body portion 131a is controlled to be 100 to 1000mm/s, for example, 100mm/s, 200mm/s, 300mm/s, 400mm/s, 500mm/s, 600mm/s, 700mm/s, 800mm/s, 900mm/s, 1000mm/s, or the like in this embodiment. It can be appreciated that the air permeability is too small, the efficiency of the rear cavity gas penetrating the main body portion 131a is reduced, the acoustic performance of the internal molecular sieve powder 132 is affected, the air permeability is too large, the size of the holes in the main body portion 131a is larger or the structure of the holes is sparse, the interception of the molecular sieve powder 132 is easily affected, and the powder leakage problem occurs. The air permeability of the main body 131a is controlled within a proper range, so that the molecular sieve powder 132 can be intercepted, and the stacking pore structure of the molecular sieve powder can provide certain acoustic performance.

In some possible embodiments, the filaments comprise at least one of chemical fibers, modified chemical fibers, and natural fibers. Specifically, usable chemical fibers include polypropylene fibers, viscose fibers, polyamide fibers, polyester fibers, polyacrylonitrile fibers, and the like. The modified chemical fiber can be prepared by modifying the chemical fibers such as polypropylene fiber, viscose fiber, polyamide fiber, polyester fiber, polyacrylonitrile fiber and the like. Natural fibers include cotton, hemp, wool, silk, and the like. The fiber yarn used in this embodiment is of various types and wide sources, and one of the fiber yarns can be selected according to the actual product performance requirements, or two or more fiber yarns can be mixed.

In some possible embodiments, the melting point of the filaments is greater than 100 ℃, e.g., 110 ℃, 120 ℃, 130 ℃, 140 ℃, etc. It will be appreciated that the temperature of the rear cavity of the sound emitting device 100 may reach 100 ℃, and that the melting point of the filament is selected to be greater than 100 ℃, so as to prevent the melting of the main body portion 131 a. The hole structure of the main body portion 131a and the air permeability of the holes are affected after the fiber yarns are melted, which will result in the influence of acoustic performance, so that the fiber yarns are selected to have a melting point of more than 100 ℃ to help the acoustic assembly 130 maintain acoustic performance in a high-temperature working environment.

In some possible embodiments, the body portion 131a has an areal density of 15-550g/m ², such as ,15g/m²、50g/m²、100g/m²、150g/m²、200g/m²、250g/m²、300g/m²、350g/m²、400g/m²、450g/m²、500g/m²、550g/m², or the like. It can be appreciated that the surface density of the main body 131a is too small, so that the porous structure thereof is sparse, and the molecular sieve powder 132 cannot be effectively intercepted, while the surface density is too large, and the structure is too compact, which will affect the air inlet and outlet, affect the air adsorption and desorption functions of the internal molecular sieve powder 132, and occupy too much back cavity space. The surface density of the main body 131a is controlled within a proper range, so that the molecular sieve powder 132 can be effectively intercepted and adverse effects on the gas adsorption and desorption functions of the molecular sieve powder 132 can be avoided.

In some possible embodiments, the thickness of the body portion 131a is 0.05-4mm, e.g., 0.05mm, 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 3.5mm, 4mm, etc. It can be understood that if the thickness of the main body 131a is too thin, the porous structure formed by the fiber filaments is loose, the molecular sieve powder 132 is not blocked, and if the thickness is too thick, the air flow in and out is affected, the air adsorption and desorption function of the internal molecular sieve powder 132 is affected, and too much rear cavity space is occupied. The thickness of the main body 131a is controlled to be in the range of 0.05-4mm, so that the blocking effect of the molecular sieve 132 is achieved, and the smooth in-and-out of the rear cavity gas is maintained. Further, the thickness of the body portion 131a may be controlled to be between 0.1 and 1mm to obtain optimal air permeability.

In some possible embodiments, the sound absorption coefficient of the body portion 131a is greater than 0.3, e.g., 0.31, 0.33, 0.35, 0.4, 0.45, 0.5, etc. It will be appreciated that the greater the coefficient of sound absorption of the body portion 131a, which may be indicative of the ability of the material to absorb sound energy, the greater the sound absorption thereof, which may reduce reflections and resonances of sound waves. The main body 131a has a sound absorption coefficient greater than 0.3, and thus has a function of improving the resonance frequency of the sound generating device 100, so that the overall sound absorption effect of the sound absorbing assembly 130 can be improved on the basis that the molecular sieve powder 132 has the sound absorption effect, and the low-frequency performance of the sound generating device 100 can be further improved.

The molecular sieve powder 132 in this example has an average particle diameter of more than 10. Mu.m, for example, 11. Mu.m, 12. Mu.m, 13. Mu.m, 14. Mu.m, 15. Mu.m, etc. It can be understood that the molecular sieve powder 132 has a plurality of pore canal and pore structural units with uniform pore diameters, and has adsorption and desorption effects on air and good sound absorption performance. The average particle size of the molecular sieve powder 132 affects the number of pore building blocks per unit volume, and the particle size of common molecular sieve powder materials is typically 1-2 μm, with a smaller number of pore building blocks per unit volume and poorer acoustic properties. The molecular sieve powder 132 of the embodiment has the advantages that the D50 is larger than 10 μm in the test of the laser particle size analyzer, the internal structure of the molecular sieve powder 132 is compact, more pore structure units can be arranged in unit volume, the acoustic performance is better, the molecular sieve powder 132 with the particle size larger than or equal to 10 μm is not easy to generate dust, and the damage to the respiratory system of a human body in the operation process is smaller.

In some possible embodiments, the ratio of pore volume of micropores to pore volume of mesopores in the molecular sieve powder 132 is greater than 0.5, e.g., 0.55, 0.6, 0.65, 0.7, 0.8, etc. It can be understood that the pore diameter of the micropores is smaller than that of the mesopores, the micropores can absorb and desorb nitrogen and oxygen molecules in the air, the pore volume of the micropores is smaller than 0.5, and the adsorption and desorption functions of the molecular sieve powder 132 on the air are reduced, so that the acoustic performance is affected. Molecular sieve powders 132 having a pore distribution ratio with a micropore ratio greater than 0.5 will have better acoustic properties.

In some possible embodiments, the volume of the molecular sieve powder 132 is greater than 50% of the volume of the receiving space, e.g., 55%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc. It will be appreciated that the housing 131 needs to occupy a certain volume in the rear cavity, the molecular sieve powder 132 is located in the accommodating space of the housing 131, and in the case that the volume of the molecular sieve powder 132 is less than 50% of the volume of the accommodating space, the entire sound absorbing assembly 130 occupies a certain volume but does not provide an effective acoustic improvement effect. Therefore, the volume of the molecular sieve powder 132 is greater than 50% of the volume of the accommodating space, and under the condition of occupying a certain volume, the filling number of the molecular sieve powder 132 is more, the number of pore channels in the molecular sieve powder 132 is more, the adsorption and desorption of the rear cavity gas are more facilitated, and a better acoustic improvement effect is provided.

In some possible embodiments, the cover portion 131b is a double sided tape, a hot melt adhesive film, a plastic film, or the same material as the main body portion 131 a. It is understood that the cover portion 131b is covered on the main body portion 131a, the molecular sieve powder 132 is limited in the housing 131, and the cover portion 131b may be made of a material having a certain adhesion function, such as a double-sided adhesive tape, a hot melt adhesive film, or the like, or may be made of a plastic film or the same material as the main body portion 131 a. When the main body 131a and the cover 131b are made of the same material, the cover 131b also has an effect of improving the resonance frequency of the acoustic device 100, as in the main body 131 a.

In some possible embodiments, the body portion 131a and the cover portion 131b are connected by means of heat fusion encapsulation or gluing. It will be appreciated that the connection between the main body 131a and the cover 131b may be selected according to the materials thereof, for example, in the case where the main body 131a and the cover 131b are made of the same material, hot-melt encapsulation is used, and in the case where the main body 131a and the cover 131b are made of different materials, and the bonding effect between the two materials is insufficient, adhesion is used. Fig. 2 is a cross-sectional view of a sound absorbing assembly 130 using an adhesive connection, and as shown in fig. 2, the sound absorbing assembly 130 includes a case 131 and a molecular sieve powder 132 filled in the case 131, the case 131 includes a main body portion 131a and a cover portion 131b, and an adhesive layer 133 is provided between the main body portion 131a and the cover portion 131b to connect the main body portion 131a and the cover portion 131 b.

In this embodiment, the shell 131 of the sound absorbing assembly 130 is made of a flexible air-permeable material, the molecular sieve powder 132 is contained, the main body 131a of the porous structure can enable the back cavity gas to smoothly enter and exit, the sound absorbing assembly has certain acoustic properties, the filament diameter of the fiber filaments is 0.05-10 μm, the air permeability of the main body 131a is 100-1000mm/s, so that the main body 131a structure can maintain good air permeability while intercepting the molecular sieve powder 132, the problem of powder leakage pollution is avoided, the average particle size of the molecular sieve powder 132 is larger than 10 μm, the particle size of the molecular sieve powder 132 is larger than that of a common molecular sieve powder material, the internal structure arrangement of the molecular sieve powder 132 is more compact, more pore structure units can be contained in a unit volume, and in addition, the molecular sieve powder 132 does not need to be bonded and molded by using an adhesive, thereby eliminating the influence of the adhesive on the blocking of the molecular sieve on the sound absorbing performance, and the sound absorbing performance is improved better.

Referring to fig. 3, the sound generating device 100 includes a sound generating unit 110, a housing 120, and an internal cavity surrounded by the housing 120 and the sound generating unit 110, where the internal cavity is filled with the sound absorbing assembly 130 as described above. The sounding body 110 divides the housing 120 into a front sound chamber and a rear sound chamber 140, and the sound absorbing assembly 130 may be filled in the rear sound chamber 140.

Alternatively, referring to fig. 4, the housing 120 includes a first case 121 and a second case 122 disposed opposite to each other, and the sound absorbing assembly 130 is interposed between the first case 121 and the second case 122, or an adhesive layer is provided on an inner wall of the housing 120 and is adhesively connected to the sound absorbing assembly 130. The sound absorbing assembly 130 is confined in the cavity of the rear sound chamber 140 of the sound generating apparatus 100 by the space-limiting action of the first and second housings 121 and 122. Or the sound absorbing assembly 130 may be attached to the inner wall of the rear acoustic chamber 140 on at least one side by an adhesive layer such as double sided tape.

The sound generating device 100 provided by the invention solves the technical problem that sound absorbing particles are easy to break, so that the sound generating unit 110 is polluted. Compared to the prior art, the sound generating device 100 provided in the embodiment of the present invention may refer to the beneficial effects of the sound absorbing assembly 130 in the above embodiment, and will not be described herein.

The embodiment of the invention also provides an electronic device, which comprises the sound generating device 100 described in the above embodiment.

In this embodiment, the electronic device includes a mobile phone, a notebook computer, a tablet computer, a VR (Virtual Reality) device, an AR (Augmented Reality ) device, a TWS (True Wireless Stereo, true wireless) earphone, an intelligent sound box, an intelligent wearable device, and the like.

Compared with the prior art, the beneficial effects of the electronic device provided by the embodiment of the invention are the same as those of the sound generating device 100 of the above embodiment, and are not described herein.

The sound absorbing assembly of the present invention is described in detail below in specific examples and comparative examples. It is to be understood that the following description is exemplary only and is not intended to limit the invention in any way. Moreover, the comparative examples were chosen to demonstrate the technical progress of the present invention, and the technical solutions in the comparative examples are not all conventional in the art.

Example 1

The main body 131a and the cover 131b are each made of a porous membrane material formed by stacking filaments of polypropylene fibers. The average wire diameter of the fiber wires in the membrane material is 5 mu m, the sound absorption coefficient of the membrane material is 0.43, the thickness of the membrane material is 0.16mm, and the air permeability of the membrane material is 290mm/s. ZSM-5 molecular sieve powder with an average particle diameter of 12 mu m and a silicon-aluminum ratio of 132 is selected.

The process for preparing the sound absorbing assembly 130 refers to the following steps:

1. And placing the membrane material in a shape covering tool manufactured according to the space shape of the rear cavity, wherein the inner volume of the tool is 0.18ml, and closing the upper die and the lower die.

2. The tooling is placed on a heating table of a vulcanizing machine, the heating temperature is set to be 130 ℃, the pressure is 0.1MPa, and the temperature and pressure are maintained for 60s.

3. And after the hot pressing is finished, taking out the cooled tool, and opening the die to obtain the space-covered main body part 131a.

4. The storage space of the body 131a obtained by punching was filled with ZSM-5 molecular sieve powder until 100% by volume of the storage space of the body 131a was filled.

5. And (3) placing the planar membrane on the upper surface of the main body 131a filled with ZSM-5 molecular sieve powder, and carrying out secondary hot pressing by using a flat plate die at the temperature of 150 ℃ and the pressure of 0.1MPa for 60s.

6. After the completion of the secondary hot pressing, the encapsulated case 131 is taken out by opening the mold, and the sound absorbing assembly 130 containing the ZSM-5 molecular sieve powder as a sound absorbing material is obtained.

7. The sound absorbing assembly 130 having a volume of 0.18ml was loaded into a speaker having a rear cavity volume of 0.29ml, and the assembly was completed to obtain an integral speaker.

Comparative example 1

Using a 0.18ml funnel measuring cup, taking 0.18ml ZSM-5 molecular sieve sound absorption particles (particles formed by bonding a plurality of ZSM-5 molecular sieve powders through an adhesive) with the particle size of 300-400 mu m, filling the particles into a loudspeaker with the rear cavity volume of 0.29ml, and sealing a filling port by PET, thereby assembling the whole loudspeaker.

Comparative example 2

The main body 131a and the cover 131b are each made of a porous membrane material formed by stacking filaments of polypropylene fibers. The average wire diameter of the fiber wires in the membrane material is 5 mu m, the sound absorption coefficient of the membrane material is 0.43, the thickness of the membrane material is 0.16mm, and the air permeability of the membrane material is 290mm/s.

4. And placing the planar membrane on the upper surface of the main body 131a, and performing secondary hot pressing by using a flat plate die, wherein the temperature is 150 ℃, the pressure is 0.1MPa, and the temperature and pressure are maintained for 60 seconds.

5. After the secondary hot pressing is completed, the mold is opened, and the packaged shell 131 is taken out, so that the sound absorbing assembly 130 is obtained.

6. The sound absorbing assembly 130 having a volume of 0.18ml was loaded into a speaker having a rear cavity volume of 0.29ml, and the assembly was completed to obtain an integral speaker.

Comparative example 3

The main body 131a and the cover 131b are each made of a porous membrane material formed by stacking filaments of polypropylene fibers. The average wire diameter of the fiber wires in the membrane material is 5 mu m, the sound absorption coefficient of the membrane material is 0.43, the thickness of the membrane material is 0.16mm, and the air permeability of the membrane material is 290mm/s. And selecting ZSM-5 molecular sieve sound absorption particles (particles formed by bonding a plurality of ZSM-5 molecular sieve powders through an adhesive), wherein the particle size is 300-400 mu m, and the silicon-aluminum ratio is 132.

4. The storage space of the body 131a obtained by punching was filled with the ZSM-5 molecular sieve sound absorbing particles until 100% by volume of the storage space of the body 131a was filled.

5. And (3) placing the planar membrane on the upper surface of the main body part 131a filled with ZSM-5 molecular sieve sound absorption particles, and carrying out secondary hot pressing by using a flat plate die at the temperature of 150 ℃ and the pressure of 0.1MPa for 60s.

6. After the completion of the secondary hot pressing, the encapsulated casing 131 is taken out by opening the mold, and the sound absorbing assembly 130 containing the ZSM-5 molecular sieve sound absorbing particles as a sound absorbing material is obtained.

The speakers used in example 1 and comparative examples 1 to 3 above were all speakers of the same type. Experimental tests were performed on speakers assembled in example 1 and comparative examples 1 to 3.

Acoustic performance evaluation the speakers assembled in example 1 and comparative examples 1 to 3 were subjected to an IMP (Impedance) test, and the resonant frequency F0 of each speaker was measured, and the results are shown in table 1 below.

TABLE 1

As can be seen from the results in table 1, the example 1 and the comparative example 1 are compared, and the resonance frequency F0 of the speaker of example 1 is lower than that of comparative example 1 by 16Hz, which means that the acoustic performance improvement effect of example 1 is stronger than that of comparative example 1, the resonance frequency of the speaker can be reduced better, the bass tone quality is better, and the difference in the form of whether the case 131 and the sound absorbing material are used or not is included between example 1 and comparative example 1, which both factors may affect the reduction effect of the resonance frequency. Further analysis shows that comparative example 2 can lower the resonant frequency of the speaker by 6Hz when the sound absorbing assembly 130 is made of only the material of the housing 131, which means that the material of the housing 131 itself also has a certain acoustic improvement performance. In combination with the comparison of example 1 and comparative example 3, it was found that the resonance frequency F0 of the speaker of example 1 was 10Hz lower than that of comparative example 3, indicating that the form of loading the molecular sieve powder 132 had a lower resonance frequency than the form of loading the large-particle-diameter sound-absorbing particles in the case of 100% filling in the same volume of the housing 131, and had a better sound quality, because the average particle diameter of the sound-absorbing particles of comparative example 3 was larger, a larger gap space was generated when the particles were piled up than in the powder filling manner of example 1, resulting in a certain space waste, while the generation of the gap space of the loading of the molecular sieve powder 132 of example 1 was smaller, which could increase the volume of the effective sound-absorbing material in the sound-absorbing assembly 130, so that the effect of lowering the resonance frequency was better. Therefore, the sound absorbing assembly 130 provided by the embodiment of the invention has the advantages that on one hand, the particle size of the molecular sieve powder 132 is smaller, the volume of the rear cavity can be effectively filled, and on the other hand, the shell 131 with the acoustic improvement performance is added, so that the effect of reducing the resonance frequency of the loudspeaker is better.

Reliability test the speakers of example 1 and comparative example 1 were continuously energized for 24 hours at a set voltage of 2.2V at-20C with a BFPP signal. After the experiment is finished, the resonant frequency F0 of each group of speakers is measured, and the powder pollution condition of the rear cavity is observed after the product is disassembled. The test results are shown in table 2 below.

TABLE 2

As can be seen from the results in table 2, the speaker of example 1 showed a small change in F0 of 3Hz and a large change in F0 of 13Hz after the low temperature BFPP test. After the product is disassembled. The speaker of example 1 has no broken powder, and the speaker of comparative example 1 has broken powder pollution, because the membrane material adopted by the housing 131 of example 1 has proper wire diameter, thickness and air permeability, and can effectively intercept the filled molecular sieve powder 132 through the encapsulation of the housing 131 while providing certain acoustic improvement performance, which indicates that the sound absorbing assembly 130 of the embodiment of the invention effectively avoids the broken powder pollution of sound absorbing particles and is more tolerant to severe reliability conditions.

Roller drop test example 1 and comparative example 1 speakers were assembled in a 200g drop tool, 1m height, and dropped 400 times. And disassembling the product after the experiment, and observing the pollution condition of the powder in the rear cavity. The test results are shown in table 3 below.

TABLE 3 Table 3

Experimental group	Dismantling the product and powder pollution of the rear cavity
		Example 1	Without any means for
Comparative example 1	With pollution of broken powder

As can be seen from the results in table 3, the speaker of example 1 was disassembled, and the particles of the speaker of comparative example 1 were contaminated by broken powder, because the membrane material used in the housing 131 of example 1 had a suitable wire diameter, thickness and air permeability, and the filled molecular sieve powder 132 was effectively intercepted by the encapsulation of the housing 131 while providing a certain acoustic improvement performance, which indicates that the sound absorbing assembly 130 of the present invention effectively avoided the broken powder of the sound absorbing particles, and was more resistant to severe reliability conditions.

The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims

1. The sound absorbing assembly is characterized by comprising a shell and molecular sieve powder filled in the shell, wherein the shell is made of flexible breathable materials, the shell comprises a main body part and a sealing cover part, an accommodating space is defined by the main body part, the molecular sieve powder is filled in the accommodating space, the sealing cover part is arranged on the main body part in a covering mode to seal the accommodating space, the main body part is of a porous structure formed by stacking fiber filaments, the filament diameter of the fiber filaments is 0.05-10 mu m, the air permeability of the main body part is 100-1000mm/s, and the average particle size of the molecular sieve powder is larger than 10 mu m.

2. The sound absorbing assembly of claim 1, wherein the fiber filaments comprise at least one of chemical fibers, modified chemical fibers, and natural fibers;

And/or the fiber filaments have a melting point greater than 100 ℃.

3. The sound absorbing assembly of claim 1, wherein the body portion has an areal density of 15-550g/m ²;

And/or the thickness of the main body part is 0.05-4mm.

4. The sound absorbing assembly of claim 1, wherein the body portion has a sound absorption coefficient greater than 0.3.

5. The sound absorbing assembly of claim 1, wherein the ratio of pore volume of micropores to pore volume of mesopores in the molecular sieve powder is greater than 0.5.

6. The sound absorbing assembly of claim 1, wherein the volume of the molecular sieve powder is greater than 50% of the volume of the receiving space.

7. The sound absorbing assembly of claim 1, wherein the cover portion is a double sided adhesive, a hot melt adhesive film, a plastic film, or the same material as the main body portion.

8. The sound absorbing assembly of claim 1, wherein the body portion and the cover portion are joined by hot melt encapsulation or adhesive.

9. A sound generating device, comprising a sound generating unit, a housing, and an internal cavity surrounded by the housing and the sound generating unit, wherein the internal cavity is filled with the sound absorbing assembly according to any one of claims 1 to 8.

10. The sound emitting apparatus of claim 9, wherein the housing comprises oppositely disposed first and second housings, the sound absorbing assembly sandwiched between the first and second housings;

11. An electronic device comprising the sound emitting apparatus according to claim 9 or 10.