Sound absorption assembly, sound production device and electronic equipment
By filling the speaker's back cavity with large-particle molecular sieve powder and utilizing the sound absorption performance of the shell, the problem of sound absorption particles being easily broken and adhesive blocked is solved, and the low-frequency performance and acoustic improvement of the speaker are improved, avoiding powder pollution .
Patent Information
- Application Number
- CN202411376354.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-01-07
AI Technical Summary
The sound-absorbing particles filled in the rear cavity of existing speakers are prone to shattering, resulting in smaller improvements in low-frequency performance, and adhesive blocks the molecular sieve holes, affecting the acoustic performance, and prone to powder contamination problems.
Molecular sieve powder is used as sound absorbing material, by filling the sub-sieve powder in the shell, using its average particle size greater than 10 μm and a bulk density of 0.45-0.8 g/ml, a tight structure is formed to improve the sound absorption effect, and the sound absorption coefficient through the shell The main body part greater than 0.25 helps improve sound absorption performance and avoids the use of adhesive to solve the blockage problem.
It effectively improves the low-frequency acoustic performance of the speaker, reduces the resonant frequency, avoids the breakage of sound-absorbing particles and powder pollution, and improves the acoustic improvement effect and reliability.
Smart Images

Figure CN119277250A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of acoustics, and in particular to a sound absorbing component, a sound generating device and an electronic device. Background Art
[0002] In recent years, with the trend of electronic products becoming increasingly thin and light, the space left for speakers is getting smaller and smaller. With the flattening of micro speaker modules, the volume of the acoustic back cavity is reduced. In order to solve the problem of reduced low-frequency performance of the speaker caused by reduced space, sound-absorbing particles made of porous materials can be filled into the back cavity, and the special physical channel structure inside the porous material can be used to quickly adsorb and desorb the gas in the back cavity, so as to achieve the virtual enlargement effect of the resonance space of the speaker's acoustic back cavity, thereby effectively reducing the speaker's resonance frequency F0 and improving low-frequency sensitivity.
[0003] At present, the average particle size of the sound-absorbing particles filled in the rear cavity of the speaker is 300-400μm, and the filling volume of the sound-absorbing particles accounts for up to about 80% of the total volume of the rear cavity. In addition, there are gaps when these sound-absorbing particles are stacked, and they cannot effectively fill the volume of the rear cavity, resulting in a decrease in the acoustic improvement effect. In the production of sound-absorbing particles, adhesives need to be added to form particles. The adhesives will block some pores of the molecular sieve raw powder, causing further loss of acoustic performance. In addition, the sound-absorbing particles move and collide in the rear cavity, which makes them prone to breakage and powder contamination of the sound-emitting monomers. Summary of the invention
[0004] The main purpose of the present invention is to provide a sound absorbing component, a sound-generating device and an electronic device, aiming to solve the technical problem that the sound absorbing particles filled in the rear cavity of the existing speaker are easy to break and the low-frequency performance of the speaker is slightly improved.
[0005] To achieve the above-mentioned purpose, the present invention provides a sound absorbing component, comprising a shell and a molecular sieve powder filled in the shell, the shell comprising a main body and a cover part, the main body defines a accommodating space, the molecular sieve powder is filled in the accommodating space, the cover part is covered on the main body to seal the accommodating space, wherein at least a portion of the main body is formed as a sound absorbing structure, the sound absorption coefficient of the main body is greater than 0.25, the average particle size of the molecular sieve powder is greater than 10 μm, and the packing density of the molecular sieve powder is 0.45-0.8 g / ml.
[0006] In one embodiment, the main body is formed into a porous structure formed by stacking fiber filaments, and the fiber filaments include at least one of chemical fibers, modified chemical fibers and natural fibers.
[0007] In one embodiment, the fiber filament has a diameter of 0.05-10 μm;
[0008] And / or, the melting point of the fiber filaments is greater than 100°C.
[0009] In one embodiment, the air permeability of the main body is 150-1000 mm / s.
[0010] In one embodiment, the surface density of the main body is 20-600 g / m 2 .
[0011] In one embodiment, the thickness of the main body is 0.08-4.5 mm;
[0012] And / or, the silicon to aluminum ratio of the molecular sieve powder is less than 200.
[0013] In one embodiment, the volume of the molecular sieve powder accounts for more than 55% of the volume of the containing space.
[0014] In one embodiment, the sealing cover is a breathable structure, a sound-absorbing structure or a sealed structure.
[0015] In one embodiment, the main body and the cover are connected by hot-melt sealing or gluing.
[0016] The present invention further provides a sound-generating device, comprising a sound-generating unit, a shell, and an internal cavity surrounded by the shell and the sound-generating unit, wherein the internal cavity is filled with the sound-absorbing component described above.
[0017] In one embodiment, the housing comprises a first shell and a second shell arranged opposite to each other, and the sound absorbing assembly is sandwiched between the first shell and the second shell;
[0018] Alternatively, an adhesive layer is provided on the inner wall of the shell, and the adhesive layer is adhesively connected to the sound absorbing component.
[0019] The present invention also provides an electronic device, comprising the sound generating device as described above.
[0020] The present invention provides a sound absorbing component, a sound-generating device and an electronic device. The sound absorbing component includes a shell and molecular sieve powder filled in the shell. The shell includes a main body and a cover part. The main body defines a storage space. The molecular sieve powder is filled in the storage space. The cover part is covered on the main body to seal the storage space. At least a portion of the main body is formed as a sound absorbing structure. The sound absorption coefficient of the main body is greater than 0.25. The average particle size of the molecular sieve powder is greater than 10 μm, and the bulk density of the molecular sieve powder is 0.45-0.8 g / ml. At least part of the main body is formed into a sound-absorbing structure, and the sound absorption coefficient of the main body is greater than 0.25. Therefore, while the molecular sieve powder plays a role in sound absorption, the main body can also assist in improving the sound absorption performance. The main body can also accommodate the molecular sieve powder, intercept the diffusion of the molecular sieve powder to the rear sound cavity, and solve the problem of powder leakage pollution. The average particle size of the molecular sieve powder is greater than 10μm, and the packing density is 0.45-0.8g / ml, which is larger than the particle size of the common molecular sieve powder material. The larger packing density also makes the internal structure of the molecular sieve powder more tightly arranged, and more pore structure units can be contained in a unit volume. Moreover, the molecular sieve powder does not need to be bonded and formed with an adhesive relative to the sound-absorbing particles, thereby solving the problem of the adhesive in the sound-absorbing particles blocking the molecular sieve pores and having better acoustic improvement performance. In addition, since the sound absorption coefficient of the main body is greater than 0.25, the main body has a certain sound absorption effect, thereby improving the sound absorption capacity of the sound-absorbing component and the sound absorption effect, thereby effectively improving the low-frequency acoustic performance of the sound-generating device. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present drawings or related technologies, the drawings required for use in the embodiments or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present drawings. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.
[0022] Figure 1 A cross-sectional view of an embodiment of a sound absorbing assembly according to the present invention;
[0023] Figure 2 A cross-sectional view of another embodiment of the sound absorbing assembly according to the present invention, which is connected by adhesive bonding;
[0024] Figure 3 It is a cross-sectional view of an embodiment of the sound-generating device according to the present invention;
[0025] Figure 4 It is a cross-sectional view of another embodiment of the sound-generating device according to the present invention.
[0026] Description of reference numerals:
[0027] 100. sound generating device; 110. sound generating unit;
[0028] 120, housing; 121, first housing; 122, second housing;
[0029] 130, sound absorbing component; 131, shell; 131a, main body; 131b, cover; 132, molecular sieve powder; 133, adhesive layer;
[0030] 140. Posterior vocal cavity.
[0031] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0032] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.
[0033] The embodiment of the present invention provides a sound absorbing assembly 130, Figure 1 This is a cross-sectional view of a sound absorbing component according to an embodiment of the present invention, referring to Figure 1 The sound absorbing component 130 includes a shell 131 and a molecular sieve powder 132 filled in the shell 131, the shell 131 includes a main body 131a and a cover 131b, the main body 131a defines a receiving space, the molecular sieve powder 132 is filled in the receiving space, and the cover 131b is covered on the main body 131a to seal the receiving space, wherein at least a portion of the main body 131a is formed as a sound absorbing structure, the sound absorption coefficient of the main body 131a is greater than 0.25, the average particle size of the molecular sieve powder 132 is greater than 10μm, and the packing density of the molecular sieve powder 132 is 0.45-0.8g / ml.
[0034] In this embodiment, the molecular sieve powder 132 is confined in the shell 131 to prevent the molecular sieve powder 132 from diffusing outside the accommodation space. At least part of the main body 131a is formed as a sound-absorbing structure with a sound-absorbing function. The sound-absorbing structure may include a porous sound-absorbing structure, a resonant sound-absorbing structure, and a special sound-absorbing structure. The porous sound-absorbing structure absorbs sound energy through the friction between the sound wave and the surface of the material. The resonant sound-absorbing structure absorbs sound energy through resonance. The special sound-absorbing structure is suitable for specific sound-absorbing needs. The sound absorption coefficient of the main body 131a is greater than 0.25, for example, 0.28, 0.3, 0.33, 0.35, 0.4, 0.45, 0.5, etc. It can be understood that the sound absorption coefficient can characterize the ability of the material to absorb sound energy. The larger the sound absorption coefficient of the main body 131a, the stronger its sound absorption ability is, which can reduce the reflection and resonance of the sound wave. The sound absorption coefficient of the main body 131a is greater than 0.25, which means that it has the function of improving the resonance frequency of the sound-generating device 100. Therefore, on the basis of the sound absorption effect of the molecular sieve powder 132, the overall sound absorption effect of the sound-absorbing component 130 can be improved, which is conducive to further improving the low-frequency performance of the sound-generating device 100.
[0035] In some feasible embodiments, the main body 131a is formed into a porous structure formed by stacking fiber filaments, and the fiber filaments include at least one of chemical fibers, modified chemical fibers and natural fibers. Specifically, the chemical fibers that can be used include polypropylene fibers, viscose fibers, polyamide fibers, polyester fibers, polyacrylonitrile fibers, etc. The modified chemical fibers can be prepared by modifying the above-mentioned chemical fibers such as polypropylene fibers, viscose fibers, polyamide fibers, polyester fibers, polyacrylonitrile fibers, etc. Natural fibers include cotton, linen, wool, silk, etc. There are many types of fiber filaments that can be used in this embodiment, and the sources are wide. Fiber filaments of one material can be selected according to the actual product performance requirements, or fiber filaments of two or more materials can be mixed.
[0036] In some feasible embodiments, the diameter of the fiber filaments is 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 131a can be, and a better 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 molecular sieve powder 132. The minimum value of the wire diameter of this embodiment can reach 0.05 μm, forming a membrane material with excellent thickness and air permeability performance, which is used to make the main body 131a.
[0037] In some feasible implementations, the melting point of the fiber filaments is greater than 100°C, for example, 102°C, 103°C, 105°C, 110°C, etc. It is understandable that the temperature of the rear cavity of the sound-generating device 100 can reach 100°C, and the melting point of the fiber filaments is selected to be greater than 100°C, which can prevent the main body 131a from melting. After the fiber filaments melt, the parameters such as the pore structure and air permeability of the pores of the main body 131a are affected, which will lead to the impact of acoustic performance. Therefore, the melting point of the fiber filaments is selected to be greater than 100°C, which helps the sound-absorbing component 130 maintain acoustic performance in a high-temperature working environment.
[0038] In some feasible embodiments, the air permeability of the main body 131a is 150-1000mm / s, for example, 150mm / s, 200mm / s, 300mm / s, 400mm / s, 500mm / s, 600mm / s, 700mm / s, 800mm / s, 900mm / s, 1000mm / s, etc. If the air permeability is too small, the efficiency of the back cavity gas passing through the main body 131a will be reduced, affecting the adsorption and desorption rate of the internal molecular sieve powder 132, and further affecting the sound absorption effect; if the air permeability is too large, it means that the size of the pores in the main body 131a is too large or the pore structure is sparse, which is easy to affect the interception of the molecular sieve powder 132 and cause powder leakage. Controlling the air permeability of the main body 131a within an appropriate range can not only intercept the molecular sieve powder 132, but also its own stacked pore structure can provide certain acoustic performance.
[0039] In some feasible embodiments, the surface density of the main body 131a is 20-600 g / m 2 , for example, 20g / 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 / m 2 , 500g / m 2 , 550g / m 2 , 600g / m 2Etc. It is understandable that if the surface density of the main body 131a is too small, its porous structure will be sparse and unable to effectively intercept the molecular sieve powder 132, while if the surface density is too large and the structure is too dense, it will affect the in and out of the airflow, affect the air adsorption and desorption function of the internal molecular sieve powder 132, and occupy too much back cavity space. Controlling the surface density of the main body 131a within a suitable range can effectively intercept the molecular sieve powder 132 and avoid adverse effects on the gas adsorption and desorption function of the molecular sieve powder 132. The surface density of the main body 131a can be further controlled to be 35-100g / m 2 to obtain a main body 131a structure that can effectively intercept the molecular sieve powder 132 and has good acoustic performance.
[0040] In some feasible embodiments, the thickness of the main body 131a is 0.08-4.5mm, for example, 0.08mm, 0.1mm, 0.5mm, 1mm, 2mm, 3mm, 3.5mm, 4mm, 4.5mm, etc. It is understandable that if the thickness of the main body 131a is too thin, the porous structure composed of the fiber filaments is loose and cannot effectively intercept the molecular sieve powder 132, and if the thickness is too thick, it will affect the airflow in and out of the main body 131a, affect the air adsorption and desorption function of the internal molecular sieve powder 132, and occupy too much back cavity space. Controlling the thickness of the main body 131a within the range of 0.08-4.5mm can keep the back cavity gas smoothly in and out while intercepting the molecular sieve powder 132. The thickness of the main body 131a can also be further controlled within the range of 0.1-1mm to obtain the best air permeability.
[0041] The average particle size of the molecular sieve powder 132 of this embodiment is greater than 10μm, for example, 11μm, 12μm, 13μm, 14μm, 15μm, etc. It can be understood that the molecular sieve powder 132 has many pores and holes with uniform pore size, which are pore structure units, and has an adsorption and desorption effect on air, and has good sound absorption performance. The average particle size of the molecular sieve powder 132 affects the number of pore structure units per unit volume. The particle size of common molecular sieve powder materials is usually 1-2μm, the number of pore structure units per unit volume is small, and the acoustic performance is poor. The molecular sieve powder 132 of this embodiment is tested under a laser particle size analyzer. D50 is greater than or equal to 10μm. The internal structure of the molecular sieve powder 132 is closely arranged, and there can be more pore structure units per unit volume, which has better acoustic performance, and the molecular sieve powder 132 with a particle size greater than or equal to 10μm is not easy to dust, and it is less harmful to the human respiratory system during operation.
[0042] The packing density of the molecular sieve powder 132 of the present embodiment is 0.45-0.8g / ml, for example, 0.45g / ml, 0.5g / ml, 0.6g / ml, 0.7g / ml, 0.75g / ml, 0.8g / ml, etc. It can be understood that the packing density of the molecular sieve powder 132 refers to the mass of the molecular sieve powder 132 per unit volume when the molecular sieve powder 132 is freely filled in a container and the container is just filled, which reflects the degree of compactness between the molecular sieve powders 132. The size of the packing density will affect the use effect and application scope of the molecular sieve powder 132. In the present embodiment, the smaller the packing density of the molecular sieve powder 132, the looser the molecular sieve powder 132, the larger the gap space in the shell 131, the fewer the pore structure units of the molecular sieve powder 132 per unit volume, the worse the acoustic performance, and the improvement of the packing density also has certain limitations. Different types of molecular sieve powders 132 have different packing densities, which mainly depend on factors such as the particle size, specific surface area, porosity, and mechanical strength of the molecular sieve powder 132. The molecular sieve powder 132 in this embodiment has a packing density in the range of 0.45-0.8 g / ml, has a large mechanical strength, and has a compact internal structure, so it has a high packing density, so under the same volume, there can be more porous structural units to improve the acoustic performance.
[0043] In some feasible embodiments, the silicon-aluminum ratio of the molecular sieve powder 132 is less than 200, for example, 80, 100, 130, 150, 180, etc. It is understandable that the larger the silicon-aluminum ratio of the molecular sieve powder 132, the higher the requirements for raw materials and the greater the difficulty of production. The silicon-aluminum ratio of the molecular sieve powder 132 of this embodiment is less than 200. While having the ability to adsorb and desorb molecules in the air, the requirements for raw materials for synthesizing the molecular sieve powder 132 are reduced, the production cost is reduced, and it is easier to synthesize crystals with an average particle size greater than 10 μm.
[0044] In some feasible embodiments, the volume of the molecular sieve powder 132 accounts for a proportion of the volume of the accommodation space that is greater than 55%, for example, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc. It is understandable that the shell 131 needs to occupy a certain volume in the back cavity, and the molecular sieve powder 132 is located in the accommodation space of the shell 131. When the volume of the molecular sieve powder 132 accounts for a proportion of the volume of the accommodation space that is less than 55%, the entire sound absorbing assembly 130 occupies a certain volume but cannot provide an effective acoustic improvement effect. Therefore, when the volume of the molecular sieve powder 132 accounts for a proportion of the volume of the accommodation space that is greater than 55%, when occupying a certain volume, the filling amount of the molecular sieve powder 132 is greater, and the number of pores in the molecular sieve powder 132 is greater, which is more conducive to the adsorption and desorption of the gas in the back cavity, and provides a better acoustic improvement effect.
[0045] In some feasible embodiments, the cover portion 131b is a breathable structure, a sound-absorbing structure or a closed structure. The breathable structure allows air molecules to pass through, and the cover portion 131b with a breathable structure can also have certain acoustic properties. The cover portion 131b with a sound-absorbing structure can use the same material as the main body 131a. The cover portion 131b with a closed structure mainly serves to seal the accommodation space.
[0046] In some feasible embodiments, the main body 131a and the cover 131b are connected by hot-melt packaging or gluing. It is understandable that the connection method between the main body 131a and the cover 131b can be selected according to the materials of the two. For example, when the main body 131a and the cover 131b are made of the same material, hot-melt packaging is used. When the main body 131a and the cover 131b are made of different materials and the bonding effect between the two materials is insufficient, gluing is used. Figure 2 FIG. 1 is a cross-sectional view of a sound absorbing assembly 130 connected by adhesive bonding, as shown in FIG. Figure 2 As shown, the sound absorbing component 130 includes a shell 131 and a molecular sieve powder 132 filled in the shell 131. The shell 131 includes a main body 131a and a cover 131b. An adhesive layer 133 is provided between the main body 131a and the cover 131b to connect the main body 131a and the cover 131b.
[0047] In the present embodiment, at least a portion of the main body 131a is formed as a sound-absorbing structure, and the sound absorption coefficient of the main body 131a is greater than 0.25. Therefore, while the molecular sieve powder 132 plays a role in sound absorption, the main body 131a can also assist in improving the sound absorption performance. The main body 131a can also accommodate the molecular sieve powder 132, intercept the diffusion of the molecular sieve powder 132 to the rear sound cavity, and solve the problem of powder leakage pollution. The average particle size of the molecular sieve powder 132 is greater than 10 μm, and the packing density is 0.45-0.8 g / ml, which is larger than the particle size of the common molecular sieve powder 132 material. The larger packing density also makes the internal structure of the molecular sieve powder 132 more tightly arranged, and more pore structure units can be included in a unit volume. Moreover, the molecular sieve powder 132 does not need to be bonded and formed using an adhesive relative to the sound-absorbing particles, thereby solving the problem of the adhesive in the sound-absorbing particles occupying the filling space, and increasing the volume of the effective sound-absorbing material in the sound-absorbing component 130, so it has good acoustic improvement performance. In addition, since the sound absorption coefficient of the main body 131a is greater than 0.25, the main body 131a has a certain sound absorption effect, thereby improving the sound absorption capacity of the sound absorbing component 130 and the sound absorption effect, thereby effectively improving the low-frequency acoustic performance of the sound-generating device 100.
[0048] The embodiment of the present invention further provides a sound generating device 100, referring to Figure 3The sound device 100 includes a sound unit 110, a housing 120, and an internal cavity surrounded by the housing 120 and the sound unit 110, and the internal cavity is filled with the above-mentioned sound absorbing component 130. The sound unit 110 divides the housing 120 into a front sound cavity and a rear sound cavity 140, and the sound absorbing component 130 can be filled in the rear sound cavity 140.
[0049] Optionally, refer to Figure 4 The housing 120 includes a first housing 121 and a second housing 122 that are arranged opposite to each other, and the sound absorbing component 130 is sandwiched between the first housing 121 and the second housing 122; or, an adhesive layer is provided on the inner wall of the housing 120, and the adhesive layer is bonded and connected to the sound absorbing component 130. Through the spatial limiting effect of the first housing 121 and the second housing 122, the sound absorbing component 130 is confined in the cavity of the rear sound cavity 140 of the sound-generating device 100. Alternatively, the sound absorbing component 130 can be attached to the inner wall of at least one side of the rear sound cavity 140 by setting an adhesive layer such as a double-sided adhesive.
[0050] The sound-generating device 100 provided by the present invention solves the technical problem that the sound-absorbing particles are easily broken, resulting in contamination of the sound-generating unit 110. Compared with the prior art, the beneficial effects of the sound-generating device 100 provided by the embodiment of the present invention can refer to the beneficial effects of the sound-absorbing assembly 130 of the above embodiment, and will not be repeated here.
[0051] An embodiment of the present invention further provides an electronic device, which includes the sound-generating device 100 as described in the above embodiment.
[0052] In this embodiment, the electronic devices include mobile phones, laptop computers, tablet computers, VR (Virtual Reality) devices, AR (Augmented Reality) devices, TWS (True Wireless Stereo) headphones, smart speakers, smart wearable devices, etc.
[0053] Compared with the prior art, the beneficial effects of the electronic device provided by the embodiment of the present invention are the same as the beneficial effects of the sound-generating device 100 of the above embodiment, which will not be elaborated herein.
[0054] The sound absorbing assembly of the present invention is described in detail below with specific embodiments and comparative examples. It is worth noting that the following description is only exemplary and not a specific limitation of the present invention. Moreover, the comparative examples are selected to demonstrate the technical progress of the technical solution of the present invention, and not all of the technical solutions in the comparative examples are conventional technologies in the technical field.
[0055] Example 1
[0056] The main body 131a and the cover 131b are both made of a porous structure membrane material formed by stacking polypropylene fiber filaments. The sound absorption coefficient of the membrane material is 0.38, the thickness of the membrane material is 0.13mm, and the air permeability of the membrane material is 300mm / s. ZSM-5 molecular sieve powder is selected, with an average particle size of 15μm, a silicon-aluminum ratio of 130, and a bulk density of 0.6g / ml.
[0057] The preparation process of the sound absorbing component 130 is as follows:
[0058] 1. Place the membrane material in a molded tooling made according to the shape of the back cavity space. The internal volume of the tooling is 0.26ml, and the upper and lower molds are closed.
[0059] 2. Place the tooling on the vulcanizer heating table, set the heating temperature to 130°C, the pressure to 0.1MPa, and keep the temperature and pressure for 60s.
[0060] 3. After the hot pressing is completed, the cooled tooling is taken out and the mold is opened to obtain the main body 131a with a spatial conformation.
[0061] 4. The accommodation space of the main body 131a obtained by punching is filled with ZSM-5 molecular sieve powder until the accommodation space of the main body 131a is 100% filled by volume.
[0062] 5. Place the flat membrane material on the upper surface of the main body 131a filled with ZSM-5 molecular sieve powder, and then use a flat mold to perform secondary hot pressing at a temperature of 150°C and a pressure of 0.1 MPa, and keep the temperature and pressure for 60 seconds.
[0063] 6. After the secondary hot pressing is completed, the mold is opened and the packaged shell 131 is taken out to obtain the sound absorbing component 130 containing ZSM-5 molecular sieve powder as the sound absorbing material.
[0064] 7. The sound absorbing component 130 with a volume of 0.26 ml is loaded into the loudspeaker with a rear cavity volume of 0.35 ml, and the whole loudspeaker is obtained after the assembly is completed.
[0065] Comparative Example 1
[0066] Use a 0.26ml funnel measuring cup to take 0.26ml of ZSM-5 molecular sieve sound-absorbing particles with a particle size of 300-400μm (particles formed by bonding multiple ZSM-5 molecular sieve powders with an adhesive), fill them into a speaker with a rear cavity volume of 0.35ml, seal the filling port with PET, and assemble the entire speaker.
[0067] Comparative Example 2
[0068] The main body 131a and the cover 131b are both made of a porous structure membrane material formed by stacking fiber filaments of polypropylene fibers. The sound absorption coefficient of the membrane material is 0.38, the thickness of the membrane material is 0.13 mm, and the air permeability of the membrane material is 300 mm / s.
[0069] The preparation process of the sound absorbing component 130 is as follows:
[0070] 1. Place the membrane material in a molded tooling made according to the shape of the back cavity space. The internal volume of the tooling is 0.26ml, and the upper and lower molds are closed.
[0071] 2. Place the tooling on the vulcanizer heating table, set the heating temperature to 130°C, the pressure to 0.1MPa, and keep the temperature and pressure for 60s.
[0072] 3. After the hot pressing is completed, the cooled tooling is taken out and the mold is opened to obtain the main body 131a with a spatial conformation.
[0073] 4. Place the flat film material on the upper surface of the main body 131a, and then use a flat mold to perform secondary hot pressing at a temperature of 150°C and a pressure of 0.1MPa, and keep the temperature and pressure for 60s.
[0074] 5. After the secondary hot pressing is completed, the mold is opened and the packaged shell 131 is taken out to obtain the sound absorbing component 130.
[0075] 6. The sound absorbing component 130 with a volume of 0.26 ml is loaded into the loudspeaker with a rear cavity volume of 0.35 ml, and the whole loudspeaker is obtained after the assembly is completed.
[0076] Comparative Example 3
[0077] The main body 131a and the cover 131b are both made of a porous structure membrane material formed by stacking fiber filaments of polypropylene fibers. The sound absorption coefficient of the membrane material is 0.38, the thickness of the membrane material is 0.13mm, and the air permeability of the membrane material is 300mm / s. ZSM-5 molecular sieve sound-absorbing particles (particles formed by bonding multiple ZSM-5 molecular sieve powders with an adhesive) are selected, with a particle size of 300-400μm, a silicon-aluminum ratio of 130, and a bulk density of 0.39g / ml.
[0078] The preparation process of the sound absorbing component 130 is as follows:
[0079] 1. Place the membrane material in a molded tooling made according to the shape of the back cavity space. The internal volume of the tooling is 0.26ml, and the upper and lower molds are closed.
[0080] 2. Place the tooling on the vulcanizer heating table, set the heating temperature to 130°C, the pressure to 0.1MPa, and keep the temperature and pressure for 60s.
[0081] 3. After the hot pressing is completed, the cooled tooling is taken out and the mold is opened to obtain the main body 131a with a spatial conformation.
[0082] 4. The receiving space of the main body 131 a obtained by punching is filled with ZSM-5 molecular sieve sound-absorbing particles until the receiving space of the main body 131 a is filled with 100% of its volume.
[0083] 5. Place the flat membrane material on the upper surface of the main body 131a filled with ZSM-5 molecular sieve sound-absorbing particles, and then use a flat mold to perform secondary hot pressing at a temperature of 150° C. and a pressure of 0.1 MPa for 60 seconds.
[0084] 6. After the secondary hot pressing is completed, the mold is opened and the packaged shell 131 is taken out to obtain the sound absorbing component 130 containing ZSM-5 molecular sieve sound absorbing particles as the sound absorbing material.
[0085] 7. The sound absorbing component 130 with a volume of 0.26 ml is loaded into the loudspeaker with a rear cavity volume of 0.35 ml, and the whole loudspeaker is obtained after the assembly is completed.
[0086] It should be noted that the loudspeakers used in the above embodiment 1 and comparative examples 1-3 are all loudspeakers of the same model. Experimental tests were performed on the loudspeakers assembled in embodiment 1 and comparative examples 1-3.
[0087] Acoustic performance evaluation: The loudspeakers assembled in Example 1 and Comparative Examples 1-3 were subjected to IMP (Impedance) tests, and the resonant frequency F0 of each loudspeaker was measured and the results are shown in Table 1 below.
[0088] Table 1
[0089]
[0090] From the results in Table 1, it can be seen that, compared with Example 1 and Comparative Example 1, the resonance frequency F0 of the speaker of Example 1 is about 18 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 can better reduce the resonance frequency of the speaker, and has better bass sound quality. The variables between Example 1 and Comparative Example 1 include whether to use the shell 131 and the form of the sound absorbing material, and these two factors may affect the effect of reducing the resonance frequency. Further analysis shows that when the sound absorbing component 130 of the speaker of Comparative Example 2 only has the shell 131 material, the resonance frequency of the speaker can be reduced by 10 Hz, indicating that the shell 131 material itself also has certain acoustic improvement performance. By comparing Example 1 with Comparative Example 3, it can be found that the resonant frequency F0 of the speaker in Example 1 is 8 Hz lower than that in Comparative Example 3, indicating that under the condition of 100% filling in the same volume shell 131, the form of filling the molecular sieve powder 132 with a smaller particle size has a lower resonant frequency and better sound quality than the form of filling the sound-absorbing particles with a larger particle size. This is because the average particle size of the particles in Comparative Example 3 is larger, and when the particles are piled up, a larger gap space will be generated than the powder filling method in Example 1, resulting in a certain amount of space waste, while the gap space generated by filling the molecular sieve powder 132 in Example 1 is smaller, which can increase the volume of the effective sound-absorbing material in the sound-absorbing component 130, so the effect of reducing the resonant frequency is better. Therefore, the sound-absorbing component 130 provided in the embodiment of the present invention, on the one hand, has a smaller particle size of the molecular sieve powder 132, which can effectively fill the volume of the back cavity, and on the other hand, increases the shell 131 with acoustic improvement performance, thereby having a better effect of reducing the resonant frequency of the speaker.
[0091] Reliability test: The speakers of Example 1 and Comparative Example 1 were placed in a -20°C environment, set to a voltage of 2.2V, fed with a BFPP signal, and powered on for 24 hours. After the experiment, the resonant frequency F0 of each group of speakers was measured, and the products were disassembled to observe the powder contamination of the rear cavity. The test results are shown in Table 2 below.
[0092] Table 2
[0093]
[0094] From the results in Table 2, it can be seen that after the low-temperature BFPP test, the change in F0 of the speaker of Example 1 is relatively small, which is 8Hz, while the change in F0 of the comparative example 1 is relatively large, which is 18Hz. After disassembling the product. The speaker of Example 1 has no powder, while the speaker of the comparative example 1 has powder pollution. This is because the membrane material used in the shell 131 of Example 1 has a suitable thickness and air permeability. While providing certain acoustic improvement performance, it can effectively intercept the filled molecular sieve powder 132 through the packaging effect of the shell 131, indicating that the sound absorbing component 130 of the present invention effectively avoids the pollution of sound absorbing particles and powder, and is more resistant to harsh reliability conditions.
[0095] Drum drop test: The speakers of Example 1 and Comparative Example 1 were assembled in a 200g drop fixture, dropped from a height of 1m, and dropped 400 times. After the test, the products were disassembled and the powder contamination in the rear cavity was observed. The test results are shown in Table 3 below.
[0096] Table 3
[0097] Experimental Group Disassemble the product and check the powder contamination in the rear cavity Example 1 none Comparative Example 1 There is powder pollution
[0098] It can be seen from the results in Table 3 that the speaker of Example 1 has no powder crushing, while the sound-absorbing particles of the speaker of Comparative Example 1 are contaminated with powder crushing. This is because the membrane material used in the shell 131 of Example 1 has a suitable thickness and air permeability. While providing certain acoustic improvement performance, the filled molecular sieve powder 132 can be effectively intercepted through the packaging effect of the shell 131, which means that the sound-absorbing component 130 of the present invention effectively avoids the powder crushing of the sound-absorbing particles and is more resistant to harsh reliability conditions.
[0099] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A sound absorbing component, characterized in that: The invention comprises a shell and molecular sieve powder filled in the shell, wherein the shell comprises a main body and a cover part, the main body defines a storage space, the molecular sieve powder is filled in the storage space, and the cover part is covered on the main body to seal the storage space, wherein at least a part of the main body is formed as a sound absorbing structure, the sound absorption coefficient of the main body is greater than 0.25, the average particle size of the molecular sieve powder is greater than 10 μm, and the packing density of the molecular sieve powder is 0.45-0.8 g / ml.
2. The sound absorbing assembly according to claim 1, characterized in that The main body is formed into a porous structure formed by stacking fiber filaments, and the fiber filaments include at least one of chemical fibers, modified chemical fibers and natural fibers.
3. The sound absorbing assembly according to claim 2, characterized in that: The fiber diameter is 0.05-10 μm; And / or, the melting point of the fiber filaments is greater than 100°C.
4. The sound absorbing assembly according to claim 1, characterized in that The air permeability of the main body is 150-1000 mm / s.
5. The sound absorbing assembly according to claim 1, characterized in that: The surface density of the main body is 20-600g / m 2 .
6. The sound absorbing assembly according to claim 1, characterized in that: The thickness of the main body is 0.08-4.5 mm; And / or, the silicon to aluminum ratio of the molecular sieve powder is less than 200.
7. The sound absorbing assembly according to claim 1, characterized in that The volume of the molecular sieve powder accounts for more than 55% of the volume of the containing space.
8. The sound absorbing assembly according to claim 1, wherein: The sealing cover is a breathable structure, a sound-absorbing structure or a sealed structure.
9. The sound absorbing assembly according to claim 1, characterized in that: The main body and the cover are connected by hot-melt sealing or gluing.
10. A sound-generating device, characterized in that: The invention comprises a sound-emitting unit, a shell, and an internal cavity surrounded by the shell and the sound-emitting unit, wherein the internal cavity is filled with the sound-absorbing component according to any one of claims 1 to 9.
11. The sound generating device according to claim 10, characterized in that: The housing comprises a first shell and a second shell which are arranged opposite to each other, and the sound absorbing assembly is sandwiched between the first shell and the second shell; Alternatively, an adhesive layer is provided on the inner wall of the shell, and the adhesive layer is adhesively connected to the sound absorbing component.
12. An electronic device, characterized in that: Comprising a sound-generating device as claimed in claim 10 or 11.
Citation Information
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