Sound-absorbing component, sound-producing apparatus and electronic device

Abstract

The present invention relates to the field of acoustics. Disclosed are a sound-absorbing component, a sound-producing apparatus and an electronic device. The sound-absorbing component comprises a housing and molecular sieve powder with which the housing is filled; the housing is made of a flexible air-permeable material, and comprises a main body portion and a cover portion; the main body portion defines an accommodating space, the accommodating space being filled with the molecular sieve powder; the cover portion covers the main body portion so as to seal the accommodating space; the main body portion is formed as a porous structure by stacking fiber filaments, the filament diameter of the fiber filaments being 0.05-10 μm, the air permeability of the main body portion being 100-1000 mm / s, and the average particle size of the molecular sieve powder being greater than 10 μm. The present invention solves the technical problem that sound-absorbing particles are easily broken, resulting in the broken powder contaminating sound-producing units. Moreover, compared with sound-absorbing particles, the molecular sieve powder does not need to be bonded and molded by using a bonding agent, such that the impact on the sound-absorbing performance caused by blockage of molecular sieve pore channels due to bonding agents can be eliminated, thus achieving better acoustic improvement performance.

Description

Sound absorption assembly, sound production device and electronic equipment TECHNICAL FIELD

[0001] The present application relates to the field of acoustics, in particular to a sound absorption assembly, a sound production device and an electronic equipment. BACKGROUND

[0002] In recent years, with the increasing trend of thinness of electronic products, the space left for loudspeakers is becoming smaller. With the flattening of the micro loudspeaker module, the cavity volume of the acoustic back cavity is reduced. To solve the problem of reduced low-frequency performance of the loudspeaker caused by the reduction of space, sound absorption particles made of porous materials can be filled into the back acoustic cavity. The sound absorption particles utilize the rapid adsorption-desorption properties of the special physical pore structure inside the porous material to achieve the effect of virtually increasing the resonance space of the acoustic back cavity of the loudspeaker, thereby effectively reducing the resonance frequency F0 of the loudspeaker and improving the low-frequency sensitivity.

[0003] At present, the average particle size of the sound absorption particles filled in the back cavity of the loudspeaker is 300-400 μm, and the volume of the sound absorption particles accounts for about 80% of the total volume of the back cavity. Moreover, there is a gap space when the sound absorption particles are stacked, which cannot effectively fill the volume of the back cavity, resulting in a reduction in the acoustic improvement effect. In addition, a glue adhesive needs to be added to form the sound absorption particles, and the glue adhesive will block some of the pores of the molecular sieve powder, causing further loss of acoustic performance. Moreover, the sound absorption particles move and collide in the back cavity, which is prone to breakage and powder pollution of the sound production unit. SUMMARY

[0004] The main purpose of the present application is to provide a sound absorption assembly, a sound production device and an electronic equipment, which aims to solve the technical problem that the sound absorption particles filled in the back cavity of the existing loudspeaker are prone to breakage, resulting in pollution of the sound production unit.

[0005] To achieve the above-mentioned purpose, the present application provides a sound absorption assembly, comprising a shell and a molecular sieve powder filled in the shell, wherein the shell is a flexible and breathable material, the shell comprises a main body part and a cover part, the main body part defines a containing space, the molecular sieve powder is filled in the containing space, and the cover part is arranged on the main body part to seal the containing space. The main body part is formed into a porous structure stacked by fiber filaments, the fiber filaments have a filament diameter of 0.05-10 μm, the main body part has a gas permeability of 100-1000 mm / s, and the average particle size of the molecular sieve powder is greater than 10 μm.

[0006] In an embodiment, the fiber filaments comprise at least one of chemical fibers, modified chemical fibers and natural fibers.

[0007] And / or, the melting point of the fiber filaments is greater than 100℃.

[0008] In an embodiment, the areal density of the main body part is 15-550 g / m 2 ;

[0009] And / or, the thickness of the main body part is 0.05-4 mm.

[0010] In an embodiment, the sound absorption coefficient of the main body part is greater than 0.3.

[0011] In an embodiment, the ratio of the pore volume of micropores to the pore volume of mesopores in the molecular sieve powder is greater than 0.5.

[0012] In an embodiment, the volume ratio of the molecular sieve powder to the volume of the accommodation space is greater than 50%.

[0013] In an embodiment, the cover part is double-sided tape, hot melt adhesive film, plastic film or the same material as the main body part.

[0014] In an embodiment, the main body part and the cover part are connected by hot melt packaging or adhesion.

[0015] The present application also provides a sound emitting device, comprising a sound emitting monomer, a shell and an internal cavity surrounded by the shell and the sound emitting monomer, wherein the internal cavity is filled with the sound absorbing assembly as described above.

[0016] In an embodiment, the shell comprises a first shell and a second shell arranged oppositely, and the sound absorbing assembly is arranged between the first shell and the second shell.

[0017] Or, an adhesive layer is arranged on the inner wall of the shell, and the adhesive layer is adhesively connected with the sound absorbing assembly.

[0018] The present application also provides an electronic device comprising the sound emitting device as described above.

[0019] The application provides an acoustic absorption assembly, a sound production device and an electronic device. The acoustic absorption assembly comprises a shell and a molecular sieve powder filled in the shell. The shell is made of a flexible and breathable material. The shell comprises a main body part and a cover part. The main body part defines a containing space, and the molecular sieve powder is filled in the containing space. The cover part is arranged on the main body part to seal the containing space. The main body part is formed as a porous structure stacked by fiber filaments. The diameter of the fiber filaments is 0.05-10 microns. The air permeability of the main body part is 100-1000 mm / s. The average particle size of the molecular sieve powder is greater than 10 microns. The shell of the acoustic absorption assembly is made of a flexible and breathable material. The porous structure of the main body part can make the gas in the rear cavity flow in and out smoothly, and has certain acoustic performance. The diameter of the fiber filaments is 0.05-10 microns, and the air permeability of the main body part is 100-1000 mm / s. The main body part structure can maintain good air permeability while intercepting the molecular sieve powder, thereby avoiding the problem of powder leakage and pollution. The average particle size of the molecular sieve powder is greater than 10 microns, which is larger than the particle size of general molecular sieve powder materials. The internal structure of the molecular sieve powder is more compact, and more pore structure units can be contained in a unit volume. In addition, the molecular sieve powder does not need to be bonded and formed using a binder compared with sound absorption particles, thereby solving the problem of the binder in the sound absorption particles affecting the sound absorption performance due to the blockage of the molecular sieve pore channel, and having better acoustic improvement performance. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments or the related art, the drawings needed to be used in the embodiments or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the drawings, and for those skilled in the art, other drawings can be obtained from the structures shown in the drawings without creative labor.

[0021] Fig. 1 is a cross-sectional view of an embodiment of the acoustic absorption assembly;

[0022] Fig. 2 is a cross-sectional view of another embodiment of the acoustic absorption assembly using adhesive connection;

[0023] Fig. 3 is a cross-sectional view of an embodiment of the sound production device;

[0024] Fig. 4 is a cross-sectional view of another embodiment of the sound production device.

[0025] Legend: 100, sound production device; 110, sound production unit; 120, shell; 121, first shell; 122, second shell; 130, acoustic absorption assembly; 131, shell; 131a, main body part; 131b, cover part; 132, molecular sieve powder; 133, adhesive layer; 140, rear sound cavity.

[0026] The objectives, functional characteristics and advantages of the present application will be further described with reference to the accompanying drawings in conjunction with embodiments. DETAILED DESCRIPTION

[0027] In order to make the above objectives, characteristics and advantages of the present application more apparent, clear and complete, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0028] The present embodiment provides a sound absorption assembly 130, and Fig. 1 is a sectional view of a sound absorption assembly according to an embodiment of the present application. Referring to Fig. 1, the sound absorption assembly 130 includes a shell 131 and a molecular sieve powder 132 filled in the shell 131. The shell 131 is a flexible and breathable material. The shell 131 includes a main body part 131a and a cover part 131b. The main body part 131a defines a containing space, and the molecular sieve powder 132 is filled in the containing space. The cover part 131b is arranged on the main body part 131a to seal the containing space. The main body part 131a is formed as a porous structure stacked by fiber filaments. The diameter of the fiber filaments is 0.05-10 μm. The air permeability of the main body part 131a is 100-1000 mm / s. The average particle size of the molecular sieve powder 132 is greater than 10 μm.

[0029] In the present embodiment, the shell 131 is made of a flexible and breathable material. The flexible shell 131 can well wrap the molecular sieve powder 132 therein, and the good air permeability ensures the transmission rate of the rear cavity gas. The main body part 131a is formed as a porous structure stacked by fiber filaments. The diameter of the fiber filaments has a certain influence on the pore size and air permeability of the porous structure of the main body part 131a.

[0030] Specifically, the diameter of the fiber filaments is controlled in the range of 0.05-10 μm, for example, 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 3 μm, 5 μm, 7 μm, 10 μm, etc. The smaller the diameter of the fiber filaments, the thinner the thickness of the formed main body part 131a, and the better the air permeability can be obtained. When the diameter exceeds 10 μm, the formed pore size is larger, the air permeability is larger, and it is not easy to intercept the powder. The minimum value of the diameter of the fiber filaments in the present embodiment can reach 0.05 μm, forming a film material with excellent thickness and air permeability performance, which is used to make the main body part 131a.

[0031] In this embodiment, the air permeability of the main body 131a is controlled to be 100-1000 mm / s, for example, 100 mm / s, 200 mm / s, 300 mm / s, 400 mm / s, 500 mm / s, 600 mm / s, 700 mm / s, 800 mm / s, 900 mm / s, 1000 mm / s, etc. It is understood that if the air permeability is too low, the efficiency of gas passing through the main body 131a in the rear cavity decreases, affecting the acoustic performance of the internal molecular sieve powder 132. If the air permeability is too high, it indicates that the pore size in the main body 131a is too large or the pore structure is too sparse, which easily affects the interception of the molecular sieve powder 132, resulting in powder leakage. Controlling the air permeability of the main body 131a within a suitable range allows for the interception of the molecular sieve powder 132 while its own packed pore structure provides certain acoustic performance.

[0032] In some feasible embodiments, the fiber filaments include 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, etc. Modified chemical fibers can be prepared by modifying the aforementioned chemical fibers such as polypropylene fibers, viscose fibers, polyamide fibers, polyester fibers, and polyacrylonitrile fibers. Natural fibers include cotton, linen, wool, silk, etc. This embodiment can use a wide variety of fiber filament types from diverse sources; one type of fiber filament can be selected according to actual product performance requirements, or two or more types of fiber filaments can be mixed.

[0033] In some feasible embodiments, the melting point of the fiber filament is greater than 100°C, for example, 110°C, 120°C, 130°C, 140°C, etc. It is understood that the temperature of the rear cavity of the sound-generating device 100 can reach 100°C. Selecting a fiber filament with a melting point greater than 100°C can prevent the main body 131a from melting. If the fiber filament melts, parameters such as the pore structure and air permeability of the main body 131a will be affected, leading to an impact on acoustic performance. Therefore, selecting a fiber filament with a melting point greater than 100°C helps the sound-absorbing component 130 maintain its acoustic performance in high-temperature operating environments.

[0034] In some feasible embodiments, the areal density of the main body 131a is 15-550 g / m³. 2 For example, 15g / m 2 50g / m 2 100g / m 2 150g / m 2 200g / m 2 250g / m 2 300g / m 2 350g / m 2 400g / m 2 450g / m2 500 g / m2 2 550 g / m2 2 It can be understood that if the areal density of the main body 131a is too small, the porous structure is too sparse to effectively intercept the molecular sieve powder 132, and if the areal density is too large, the structure is too dense, which will affect the air flow in and out, affect the air adsorption and desorption function of the inner molecular sieve powder 132, and occupy too much rear cavity space. Controlling the areal density of the main body 131a within a suitable range can effectively intercept the molecular sieve powder 132 and avoid adversely affecting the gas adsorption and desorption function of the molecular sieve powder 132.

[0035] In some possible implementations, the thickness of the main body 131a is 0.05-4 mm, for example, 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 3.5 mm, 4 mm, etc. It can be understood that if the thickness of the main body 131a is too thin, the porous structure composed of fiber filaments is loose and cannot intercept the molecular sieve powder 132, and if the thickness is too thick, it will affect the air flow in and out, affect the air adsorption and desorption function of the inner molecular sieve powder 132, and occupy too much rear cavity space. Controlling the thickness of the main body 131a within the range of 0.05-4 mm can intercept the molecular sieve powder 132 while maintaining the smooth entry and exit of the rear cavity gas. Further, the thickness of the main body 131a can be controlled between 0.1-1 mm to obtain the best air permeability.

[0036] In some possible implementations, the sound absorption coefficient of the main body 131a is greater than 0.3, for example, 0.31, 0.33, 0.35, 0.4, 0.45, 0.5, etc. It can be understood that the sound absorption coefficient can represent the ability of a material to absorb sound energy, and the greater the sound absorption coefficient of the main body 131a, the stronger its sound absorption ability, which can reduce the reflection and resonance of sound waves. The sound absorption coefficient of the main body 131a is greater than 0.3, which has the function of improving the resonance frequency of the sound generating device 100, thereby improving the sound absorption effect of the sound absorption assembly 130 as a whole on the basis of the sound absorption effect of the molecular sieve powder 132, which is conducive to further improving the low-frequency performance of the sound generating device 100.

[0037] The average particle size of the molecular sieve powder 132 in this embodiment is greater than 10 μm, for example, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, etc. It can be understood that the molecular sieve powder 132 has many pore structure units with uniform pore size inside, and has good sound absorption performance. The average particle size of the molecular sieve powder 132 affects the number of pore structure units in a unit volume. The particle size of the commonly used molecular sieve powder material is usually 1-2 μm, and the number of pore structure units in a unit volume is small, and the acoustic performance is poor. The D50 of the molecular sieve powder 132 in this embodiment is greater than 10 μm under the laser particle size instrument, and the structure inside the molecular sieve powder 132 is closely arranged, and there are more pore structure units in a unit volume, and the acoustic performance is better. The molecular sieve powder 132 with a particle size greater than or equal to 10 μm is not easy to produce dust, and the harm to the respiratory system of the human body during operation is smaller.

[0038] In some possible embodiments, the ratio of the pore volume of the micropores to the pore volume of the mesopores in the molecular sieve powder 132 is greater than 0.5, for example, 0.55, 0.6, 0.65, 0.7, 0.8, etc. It can be understood that the pore size of the micropores is smaller than that of the mesopores, and the micropores can adsorb and desorb nitrogen and oxygen molecules in the air. If the proportion of the pore volume of the micropores is less than 0.5, the adsorption and desorption function of the molecular sieve powder 132 to the air will be reduced, and the acoustic performance will be affected. The molecular sieve powder 132 with a pore distribution ratio of micropores greater than 0.5 has better acoustic performance.

[0039] In some possible embodiments, the ratio of the volume of the molecular sieve powder 132 to the volume of the accommodation space is greater than 50%, for example, 55%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc. It can be understood that the shell 131 needs to occupy a certain volume in the rear cavity, and the molecular sieve powder 132 is located in the accommodation space of the shell 131. If the ratio of the volume of the molecular sieve powder 132 to the volume of the accommodation space is less than 50%, the entire sound absorption assembly 130 occupies a certain volume but does not provide effective acoustic improvement effect. Therefore, the ratio of the volume of the molecular sieve powder 132 to the volume of the accommodation space is greater than 50%, and in the case of occupying a certain volume, the filling amount of the molecular sieve powder 132 is more, and the number of channels in the molecular sieve powder 132 is more, which is more conducive to the adsorption and desorption of the gas in the rear cavity, and provides better acoustic improvement effect.

[0040] In some possible embodiments, the cover part 131b is double-sided adhesive tape, hot melt adhesive film, plastic film or the same material as the main part 131a. It can be understood that the cover part 131b is arranged on the main part 131a to confine the molecular sieve powder 132 in the shell 131. The cover part 131b is made of double-sided adhesive tape, hot melt adhesive film or other materials with certain adhesive effect. Alternatively, the cover part 131b can be made of plastic film or the same material as the main part 131a. When the main part 131a and the cover part 131b are made of the same material, the cover part 131b also has the function of improving the resonance frequency of the sound production device 100, like the main part 131a.

[0041] In some possible embodiments, the main part 131a and the cover part 131b are connected by hot melt packaging or adhesion. It can be understood that the connection mode between the main part 131a and the cover part 131b can be selected according to the materials of the two parts. For example, when the main part 131a and the cover part 131b are made of the same material, hot melt packaging is adopted. When the main part 131a and the cover part 131b are made of different materials and the adhesive effect between the two materials is insufficient, adhesion is adopted. FIG. 2 is a sectional view of the sound absorption assembly 130 connected by adhesion. As shown in FIG. 2, the sound absorption assembly 130 includes the shell 131 and the molecular sieve powder 132 filled in the shell 131. The shell 131 includes the main part 131a and the cover part 131b. The adhesion layer 133 is arranged between the main part 131a and the cover part 131b to connect the main part 131a and the cover part 131b.

[0042] In this embodiment, the shell 131 of the sound absorption assembly 130 is made of flexible and breathable material. While containing the molecular sieve powder 132, the porous structure of the main part 131a allows the gas in the rear cavity to flow in and out smoothly, has certain acoustic performance, the fiber diameter of the fiber is 0.05-10 μm, and the air permeability of the main part 131a is 100-1000 mm / s. Therefore, the main part 131a can maintain good air permeability while intercepting the molecular sieve powder 132, and the problem of powder leakage and pollution can be avoided. The average particle size of the molecular sieve powder 132 is greater than 10 μm, which is larger than the particle size of general molecular sieve powder materials. The internal structure of the molecular sieve powder 132 is more compact, and more pore structure units can be contained in a unit volume. In addition, the molecular sieve powder 132 does not need to be bonded by using an adhesive, so that the influence of the adhesive on the sound absorption performance caused by the blockage of the molecular sieve pore channel can be eliminated, and the acoustic improvement performance is better.

[0043] The embodiment of the present application also provides a sound production device 100, referring to FIG. 3, the sound production device 100 comprises a sound production unit 110, a shell 120 and an internal cavity surrounded by the shell 120 and the sound production unit 110, and the internal cavity is filled with the sound absorption assembly 130 as above. The sound production unit 110 divides the shell 120 into a front sound cavity and a rear sound cavity 140, and the sound absorption assembly 130 can be filled in the rear sound cavity 140.

[0044] Optionally, referring to FIG. 4, the shell 120 comprises a first shell 121 and a second shell 122 arranged oppositely, and the sound absorption assembly 130 is clamped between the first shell 121 and the second shell 122; or, an adhesive layer is arranged on the inner wall of the shell 120, and the adhesive layer is adhesively connected with the sound absorption assembly 130. Through the space limiting action of the first shell 121 and the second shell 122, the sound absorption assembly 130 is limited in the cavity of the rear sound cavity 140 of the sound production device 100. Or the sound absorption assembly 130 can be attached to the inner wall of at least one side of the rear sound cavity 140 through the arrangement of the double-sided adhesive layer.

[0045] The sound production device 100 provided by the present application solves the technical problem that the sound absorption particles are easy to break and cause pollution of the sound production unit 110. Compared with the prior art, the beneficial effects of the sound production device 100 provided by the embodiment of the present application can refer to the beneficial effects of the sound absorption assembly 130 of the above embodiment, which will not be repeated here.

[0046] The embodiment of the present application also provides an electronic device comprising the sound production device 100 as described in the above embodiment.

[0047] In the present embodiment, the electronic device comprises a mobile phone, a notebook computer, a tablet computer, a VR (Virtual Reality) device, an AR (Augmented Reality) device, a TWS (True Wireless Stereo) earphone, a smart speaker, a smart wearable device and the like.

[0048] Compared with the prior art, the beneficial effects of the electronic device provided by the embodiment of the present application are the same as those of the sound production device 100 of the above embodiment, which will not be repeated here.

[0049] The sound absorption assembly of the present application is described in detail below with specific embodiments and comparative examples. It should be understood that the following description is only exemplary and not a specific limitation of the present application. Moreover, the selection of the comparative examples is to prove the technical progress of the technical solutions of the present application, and the technical solutions in the comparative examples are not all conventional technologies in the technical field.

[0050] Embodiment 1

[0051] The main body part 131a and the cover part 131b are both made of a porous structure film material of polypropylene fibers. The average fiber diameter of the film material is 5 μm, the sound absorption coefficient of the film material is 0.43, the thickness of the film material is 0.16 mm, and the air permeability of the film material is 290 mm / s. The ZSM-5 molecular sieve powder has an average particle size of 12 μm and a silicon-aluminum ratio of 132.

[0052] The preparation process of the sound absorption assembly 130 is described below.

[0053] 1. The film material is placed in a shaped tooling according to the shape of the rear cavity space, the internal volume of the tooling is 0.18 ml, and the upper and lower molds are closed.

[0054] 2. The tooling is placed on the heating table of the vulcanizing machine, the heating temperature is set to 130°C, the pressure is 0.1 MPa, and the pressure is maintained for 60 s.

[0055] 3. After the hot pressing is completed, the cooled tooling is taken out, and the space-shaped main body part 131a is obtained by opening the mold.

[0056] 4. The ZSM-5 molecular sieve powder is filled in the containing space of the main body part 131a obtained by stamping until the containing space of the main body part 131a is 100% volume filled.

[0057] 5. The planar film material is placed on the upper surface of the main body part 131a filled with the ZSM-5 molecular sieve powder, and then the planar mold is used for secondary hot pressing, the temperature is 150°C, the pressure is 0.1 MPa, and the pressure is maintained for 60 s.

[0058] 6. After the secondary hot pressing is completed, the encapsulated shell 131 is taken out by opening the mold, and the sound absorption assembly 130 containing the ZSM-5 molecular sieve powder as the sound absorption material is obtained.

[0059] 7. The sound absorption assembly 130 with a volume of 0.18 ml is filled into the loudspeaker with a rear cavity volume of 0.29 ml, and the overall loudspeaker is assembled.

[0060] Comparative Example 1

[0061] 0.18 ml of ZSM-5 molecular sieve sound absorption particles (particles formed by bonding a plurality of ZSM-5 molecular sieve powders with an adhesive) with a particle size of 300-400 μm are taken using a 0.18 ml funnel measuring cup, and are filled into a loudspeaker with a rear cavity volume of 0.29 ml. The filling port is sealed by PET, and the overall loudspeaker is assembled.

[0062] Comparative Example 2

[0063] The main body 131a and the cover 131b are made of a porous structure film material made of fiber filaments of polypropylene fibers. The average filament diameter of the fiber filaments in the film material is 5 μm, the sound absorption coefficient of the film material is 0.43, the thickness of the film material is 0.16 mm, and the air permeability of the film material is 290 mm / s.

[0064] The preparation process of the sound absorption assembly 130 refers to the following steps:

[0065] 1. Place the film material in a shaped tooling made according to the shape of the back cavity space, the internal volume of the tooling is 0.18 ml, and the upper and lower molds are closed.

[0066] 2. Place the tooling on the heating table of the vulcanizing machine, set the heating temperature to 130°C, the pressure to 0.1 MPa, and the holding time to 60 s.

[0067] 3. After the hot pressing is completed, the cooled tooling is taken out, and the space-shaped main body 131a is obtained by opening the mold.

[0068] 4. Place the flat film material on the upper surface of the main body 131a, and then use a flat mold for secondary hot pressing, with a temperature of 150°C, a pressure of 0.1 MPa, and a holding time of 60 s.

[0069] 5. After the secondary hot pressing is completed, the encapsulated shell 131 is taken out by opening the mold, and the sound absorption assembly 130 is obtained.

[0070] 6. The sound absorption assembly 130 with a volume of 0.18 ml is filled into a loudspeaker with a back cavity volume of 0.29 ml, and the overall loudspeaker is assembled.

[0071] Comparative Example 3

[0072] The main body 131a and the cover 131b are made of a porous structure film material made of fiber filaments of polypropylene fibers. The average filament diameter of the fiber filaments in the film material is 5 μm, the sound absorption coefficient of the film material is 0.43, the thickness of the film material is 0.16 mm, and the air permeability of the film material is 290 mm / s. ZSM-5 molecular sieve sound absorption particles (particles formed by bonding multiple ZSM-5 molecular sieve powders with an adhesive) with a particle size of 300-400 μm and a silicon-aluminum ratio of 132 are selected.

[0073] The preparation process of the sound absorption assembly 130 refers to the following steps:

[0074] 1. Place the film material in a shaped tooling made according to the shape of the back cavity space, the internal volume of the tooling is 0.18 ml, and the upper and lower molds are closed.

[0075] 2. Place the tooling on the heating table of the vulcanizing machine, set the heating temperature to 130°C, the pressure to 0.1 MPa, and the holding time to 60 s.

[0076] 3. After the hot pressing, the cooled tooling is taken out, and the mold is opened to obtain the main body part 131a in a space covering shape.

[0077] 4. The containing space of the main body part 131a obtained by stamping is filled with ZSM-5 molecular sieve sound-absorbing particles until the containing space of the main body part 131a is 100% volume filled.

[0078] 5. A planar film material is placed on the upper surface of the main body part 131a filled with ZSM-5 molecular sieve sound-absorbing particles, and a flat plate mold is used for secondary hot pressing at a temperature of 150°C, a pressure of 0.1 MPa, and a holding time of 60 s.

[0079] 6. After the secondary hot pressing is completed, the mold is opened to take out the packaged shell 131, and a sound-absorbing assembly 130 containing ZSM-5 molecular sieve sound-absorbing particles as sound-absorbing material is obtained.

[0080] 7. The obtained sound-absorbing assembly 130 with a volume of 0.18 ml is filled into a loudspeaker with a rear cavity volume of 0.29 ml, and the overall loudspeaker is assembled.

[0081] It should be noted that the loudspeakers used in the above embodiment 1 and comparative examples 1-3 are all the same model. The loudspeakers assembled from embodiment 1 and comparative examples 1-3 are tested.

[0082] Acoustic performance evaluation: The loudspeakers assembled from embodiment 1 and comparative examples 1-3 are tested for IMP (Impedance, impedance), and the resonant frequency F0 of each loudspeaker is measured as shown in Table 1 below.

[0083] Table 1

[0084] From the results in Table 1, it can be seen that, in comparison between Example 1 and Comparative Example 1, the resonance frequency F0 of the loudspeaker of Example 1 is 16 Hz lower than that of Comparative Example 1, indicating that the acoustic performance improvement effect of Example 1 is stronger than that of Comparative Example 1, and Example 1 can better reduce the resonance frequency of the loudspeaker and has better bass sound quality. The difference between Example 1 and Comparative Example 1 includes whether the shell 131 and the form of the sound-absorbing material are used, and both factors can affect the resonance frequency reduction effect. Further analysis can find that, when the sound-absorbing assembly 130 of Comparative Example 2 only has the shell 131 material, the resonance frequency of the loudspeaker can be reduced by 6 Hz, indicating that the shell 131 material itself also has a certain acoustic improvement performance. In comparison between Example 1 and Comparative Example 3, it is found that the resonance frequency F0 of the loudspeaker of Example 1 is 10 Hz lower than that of Comparative Example 3, indicating that, in the case of 100% filling in the shell 131 of the same volume, the form of filling the molecular sieve powder 132 has a lower resonance frequency and better sound quality than the form of filling the large-particle-size sound-absorbing particles, because the average particle size of the sound-absorbing particles of Comparative Example 3 is large, and the particle accumulation will produce larger gap space than the powder filling mode of Example 1, causing a certain space waste, while the molecular sieve powder 132 of Example 1 produces smaller gap space, which can increase the volume of the effective sound-absorbing material in the sound-absorbing assembly 130, so the resonance frequency reduction effect is better. Therefore, the sound-absorbing assembly 130 provided by the embodiment of the present application can effectively fill the back cavity volume on the one hand due to the small particle size of the molecular sieve powder 132, and on the other hand can increase the shell 131 with acoustic improvement performance, thereby having a better effect of reducing the resonance frequency of the loudspeaker.

[0085] Reliability experiment test: the loudspeakers of Example 1 and Comparative Example 1 were continuously powered for 24 h in a -20℃ environment, with a voltage of 2.2V and a BFPP signal. After the experiment, the resonance frequency F0 of each group of loudspeakers was measured, and the back cavity powder pollution was observed after the product was disassembled. The test results are shown in Table 2.

[0086] Table 2

[0087] From the results in Table 2, it can be seen that, after the low-temperature BFPP experiment, the F0 change of the loudspeaker of Example 1 is small, being 3 Hz, while the F0 change of the loudspeaker of Comparative Example 1 is large, being 13 Hz. After the product is disassembled, there is no broken powder in the loudspeaker of Example 1, while there is broken powder pollution in the loudspeaker of Comparative Example 1, because the membrane material used in the shell 131 of Example 1 has a suitable wire diameter, thickness and air permeability, which can provide a certain acoustic improvement performance and effectively intercept the filled molecular sieve powder 132 through the packaging effect of the shell 131, indicating that the sound-absorbing assembly 130 of the embodiment of the present application effectively avoids the broken powder pollution of the sound-absorbing particles and is more resistant to harsh reliability conditions.

[0088] Roller drop test: the loudspeaker of example 1 and comparative example 1 was assembled in a 200g drop tool, 1m high, and dropped 400 times. After the experiment, the product was disassembled, and the back cavity powder contamination was observed. The test results are shown in Table 3 below.

[0089] Table 3

[0090] As can be seen from the results in Table 3, no powder loss was found after disassembly of the loudspeaker of example 1, and the particles of the loudspeaker of comparative example 1 were contaminated with powder, which was due to the fact that the film material used in the shell 131 of example 1 had a suitable wire diameter, thickness and air permeability, which could effectively intercept the filled molecular sieve powder 132 through the packaging effect of the shell 131 while providing certain acoustic improvement performance, indicating that the sound absorption assembly 130 of the present application effectively avoids the powder loss of the sound absorption particles and is more resistant to harsh reliability conditions.

[0091] The above is only a preferred embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A sound absorbing assembly, characterized by, The sound-absorbing assembly comprises a shell and a molecular sieve powder filled in the shell, the shell is a flexible and breathable material, the shell comprises a main body part and a cover part, the main body part defines a containing space, the molecular sieve powder is filled in the containing space, and the cover part is arranged on the main body part to seal the containing space, wherein the main body part is formed into a porous structure stacked by fiber filaments, the fiber filaments have a filament diameter of 0.05-10 μm, the main body part has a gas permeability of 100-1000 mm / s, and the average particle size of the molecular sieve powder is greater than 10 μm.

2. The sound absorption assembly of claim 1, wherein, The fiber filaments comprise at least one of chemical fibers, modified chemical fibers and natural fibers. And / or, the melting point of the fiber filaments is greater than 100 ℃.

3. The sound absorption assembly of claim 1, wherein, The areal density of the main body portion is 15-550 g / m 2 ; And / or, the thickness of the main body part is 0.05-4 mm.

4. The sound absorption assembly of claim 1, wherein, The sound-absorbing coefficient of the main body part is greater than 0.

3.

5. The sound absorption assembly of claim 1, wherein, The ratio of the pore volume of micropores to the pore volume of mesopores in the molecular sieve powder is greater than 0.

5.

6. The sound absorption assembly of claim 1, wherein, The ratio of the volume of the molecular sieve powder to the volume of the containing space is greater than 50%.

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

8. The sound absorption assembly of claim 1, wherein, The main body part and the cover part are connected by hot melt packaging or adhesion.

9. A sound producing device, characterized by The sound-emitting device comprises a sound-emitting unit, a shell and an internal cavity surrounded by the shell and the sound-emitting unit, and the internal cavity is filled with the sound-absorbing assembly.

10. The sound production device of claim 9, wherein, The shell comprises oppositely arranged first and second shell bodies, and the sound-absorbing assembly is arranged between the first and second shell bodies. Or, an adhesive layer is arranged on the inner wall of the shell, and the adhesive layer is adhesively connected with the sound-absorbing assembly.

11. An electronic device, comprising: The sound-emitting device comprises the sound-emitting device according to claim 9 or 10.

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