CN112565983A

CN112565983A - Vibrating diaphragm for sound production device and sound production device

Info

Publication number: CN112565983A
Application number: CN202011204609.2A
Authority: CN
Inventors: 惠冰; 凌风光; 李春
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2020-11-02
Filing date: 2020-11-02
Publication date: 2021-03-26

Abstract

The embodiment of the disclosure provides a vibrating diaphragm for a sound generating device and the sound generating device, wherein the vibrating diaphragm comprises at least one elastomer layer containing a foaming thermoplastic elastomer and at least one rubber layer containing rubber, the foaming thermoplastic elastomer is obtained by the thermoplastic elastomer under a foaming condition, and the foaming thermoplastic elastomer is provided with foam holes which comprise at least one of closed foam holes and open foam holes. The elastomer layer of the vibrating diaphragm provided by the embodiment of the disclosure has a structure containing the closed cells and/or the open cells, so that the sound absorption performance can be improved while the light quality is kept, and the porous structure also has a good heat insulation effect, so that the influence of temperature change on the resonant frequency F0 of the sound generating device can be compensated, and the sound generating effect of the sound generating device is improved.

Description

Vibrating diaphragm for sound production device and sound production device

Technical Field

The disclosure relates to the technical field of electronic products, in particular to a vibrating diaphragm for a sound generating device and the sound generating device.

Background

The existing diaphragm for the sound generating device mostly adopts high polymer materials, such as engineering plastics like PEEK, PAR, PEI and PI, elastomer materials like TPU and TPEE, and adhesive films like acrylic adhesive film and silica gel adhesive film. In addition, silicone rubber has good thermal stability, good hydrophobic property and excellent resilience, and is also gradually used for manufacturing diaphragms with the improvement of high power, waterproof and high sound quality requirements.

The above materials all suffer from their own disadvantages. For example, engineering plastics such as PEEK and PAR have good temperature resistance, but have poor material resilience, and the product is easy to generate film folding and cannot play a waterproof role. The melting point of TPU, TPEE and other elastomer materials is lower, and the temperature resistance is poorer. Although the silicon rubber material has good thermal stability and rebound resilience, the silicon rubber diaphragm has high product distortion due to the fact that the silicon rubber material has symmetrical chemical structure, high stereoregularity, small steric hindrance of symmetrically substituted methyl groups and relatively low modulus or hardness of the silicon rubber, and the damping performance of the material is low.

Therefore, the comprehensive performance of the diaphragm is poor, and the requirement on the comprehensive performance of the sound production device cannot be met. Therefore, it is a technical problem in the art to provide a diaphragm for a sound generating device with high comprehensive performance and high reliability.

Disclosure of Invention

An object of the embodiments of the present disclosure is to provide a diaphragm for a sound generating apparatus and a new technical solution of the sound generating apparatus.

According to a first aspect of embodiments of the present disclosure, there is provided a diaphragm for a sound-emitting device, the diaphragm including at least one elastomer layer including a foamed thermoplastic elastomer obtained under a foaming condition for the thermoplastic elastomer and at least one rubber layer including rubber, the foamed thermoplastic elastomer having cells including at least one of closed cells and open cells.

Optionally, the diaphragm includes two elastomer layers and one rubber layer, and the rubber layer is sandwiched between the two elastomer layers;

or, the diaphragm comprises one layer of the elastomer layer and two layers of the rubber layers, and the elastomer layer is clamped between the two layers of the rubber layers.

Optionally, the foamed thermoplastic elastomer comprises at least one of a foamed thermoplastic polyolefin elastomer, a foamed thermoplastic nylon elastomer, a foamed thermoplastic vulcanizate, a foamed thermoplastic polyurethane elastomer, a foamed thermoplastic polyester elastomer, and a foamed polystyrene-poly (ethylene-butylene) -polystyrene block copolymer.

Optionally, the foaming conditions are chemical foaming or physical foaming.

Alternatively, the cell size ranges from 0.1 μm to 70 μm.

Optionally, the foamed thermoplastic elastomer has a density in the range of 0.1g/cm³-0.9g/cm³。

Optionally, the foamed thermoplastic elastomer has a glass transition temperature in the range of-80 ℃ to 0 ℃.

Optionally, the elastomeric layer has a thickness in a range of 10 μm to 100 μm; the thickness range of the rubber layer is 10-120 mu m.

Optionally, the total thickness of the diaphragm is in a range of 30 μm to 300 μm.

Alternatively, the rubber includes at least one of Natural Rubber (NR), styrene-butadiene rubber (SBR), cis-Butadiene Rubber (BR), Isoprene Rubber (IR), Chloroprene Rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), chlorinated nitrile rubber (HNBR), ethylene propylene rubber (EPDM), silicone rubber (Q), fluorine rubber (FPM), polyurethane rubber (AU), acrylate rubber (ACM), chlorosulfonated polyethylene rubber (CSM), epichlorohydrin rubber (CO), polysulfide rubber, and ethylene-vinyl acetate rubber.

Optionally, the shore hardness of the diaphragm is in a range of 25A-90A.

According to a second aspect of the embodiments of the present disclosure, there is provided a sound generating device, including a sound generating device main body and the vibrating diaphragm of the first aspect, the vibrating diaphragm is disposed on the sound generating device main body.

One technical effect of the disclosed embodiment is as follows:

the embodiment of the disclosure provides a diaphragm for a sound production device, the diaphragm comprises at least one elastomer layer containing a foamed thermoplastic elastomer and at least one rubber layer containing rubber, the foamed thermoplastic elastomer is obtained by foaming the thermoplastic elastomer, the foamed thermoplastic elastomer is provided with foam holes, and the foam holes comprise at least one of closed foam holes and open foam holes. The elastomer layer of the vibrating diaphragm provided by the embodiment of the disclosure has a structure containing the closed cells and/or the open cells, and the cells can improve the sound absorption performance, improve the sound production effect of the sound production device and simultaneously give consideration to the damping performance of the sound production device. Meanwhile, the bubble hole can keep the diaphragm to have light weight, and the sound production device has lower F0 under the condition of ensuring that the modulus loss of the diaphragm is smaller.

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

Drawings

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

Fig. 1 is a schematic structural diagram of a diaphragm according to an embodiment of the disclosure;

fig. 2 is a schematic structural diagram of another diaphragm provided in the embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of another diaphragm provided in the embodiment of the present disclosure;

fig. 4 is a graph of a sound generator F0 with diaphragms of the same thickness but different stiffness provided by an embodiment of the present disclosure;

fig. 5 is a test curve of vibration displacement of different parts of a diaphragm of a sound generating apparatus according to an embodiment of the present disclosure at different frequencies;

FIG. 6 is a test curve of vibration displacement of different parts of a conventional diaphragm under different frequencies in the prior art;

FIG. 7 is a harmonic distortion (THD) test curve of a diaphragm of an embodiment provided in the present disclosure and a conventional PEEK diaphragm;

fig. 8 is a test curve (SPL curve) of loudness of a diaphragm of an embodiment of the present disclosure at different frequencies than a conventional diaphragm.

Wherein: 100-a diaphragm; 1-an elastomeric layer; 2-rubber layer.

Detailed Description

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

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

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

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

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

Referring to fig. 1 to 3, the disclosed embodiments provide a diaphragm for a sound-generating device, such as a diaphragm for a speaker, the diaphragm 100 including at least one elastomer layer 1 including a foamed thermoplastic elastomer obtained under a foaming condition for a thermoplastic elastomer, and at least one rubber layer 2 including a rubber, the foamed thermoplastic elastomer having cells including at least one of closed cells and open cells.

Specifically, after the foamed thermoplastic elastomer obtains the foam holes under the foaming condition, when the foam holes are located in the middle of the foamed thermoplastic elastomer, the foam holes may become the closed foam holes surrounded by the hole walls, and when the vibration of the diaphragm 100 causes the sound-generating device to generate sound, the closed foam holes may also vibrate therewith, and the vibration of the closed foam holes may play a good rebound role in sound, so as to enhance the sound-generating intensity and effect of the sound-generating device; when the cells are in the middle of the foamed thermoplastic elastomer or close to the surface, the cells can form a channel communicated with the outside, namely, the open cells are formed, and the open cells can prolong the path of sound transmission, so that the strength and the effect of sound production of the sound production device are further enhanced. The cell size of the cells may range from 0.1 μm to 70 μm. Preferably, the pore size of the cells may further be 0.5 μm to 50 μm. When the pore diameter of the bubble is too small, the entering and the outgoing of the sounding device are not facilitated; when the pore diameter of the bubble is too large, the sound is reflected less in the bubble, which is not beneficial to enhancing the sound production of the sound production device.

Specifically, the elastomer layer 1 and the rubber layer 2 may be joined by thermal bonding. The connection mode of thermal bonding can improve the bonding performance between the elastomer layer 1 and the rubber layer 2, so that the bonded diaphragm 100 has higher wear resistance, and the elastomer layer 1 and the rubber layer 2 are not easy to crack, and the diaphragm 100 can have higher high-temperature resistance.

The vibrating diaphragm that this disclosed embodiment provided is in containing during elastomer layer 1, elastomer layer 1 has and contains closed cell and/or open cell's porous structure can keep lighter quality when improving sound absorption performance, and this porous structure still has better temperature-isolating effect moreover, can compensate the influence of temperature variation to sound generating mechanism resonant frequency F0, is guaranteeing under the less condition of vibrating diaphragm 100 modulus loss, make sound generating mechanism have lower F0, improved sound generating mechanism's vocal effect.

Specifically, since the diaphragm 100 is a composite diaphragm including the elastomer layer 1 and the rubber layer 2, at room temperature, the diaphragm 100 is in a high elastic state, a molecular chain of the diaphragm 100 is easy to move, and the friction force between molecules is large, so the diaphragm 100 has a good damping performance, and at room temperature, the loss factor of the diaphragm 100 is greater than 0.06, preferably greater than 0.1.

The excellent damping performance allows the diaphragm 100 to have a lower impedance curve, i.e., the diaphragm 100 has a lower quality factor Q. The damping performance of the diaphragm 100 is improved, the ability of the vibration system to suppress the polarization phenomenon during the vibration process is also enhanced, and the vibration consistency is better. The common engineering plastic diaphragm has low damping, the loss factor of the diaphragm is generally less than 0.01, the damping is small, and the vibration consistency is poor.

Fig. 5 is a test curve of vibration displacement of different parts of a diaphragm of a sound generating apparatus at different frequencies according to an embodiment of the present disclosure. Fig. 6 is a test curve of vibration displacement of different parts of a conventional diaphragm under different frequencies.

Wherein, the vibrating diaphragm is a rectangular corrugated rim vibrating diaphragm. The abscissa is frequency (Hz) and the ordinate is loudness displacement (mm). And (4) taking points at the edge position and the center position of the center part of the diaphragm for testing.

It can be seen that the curves in fig. 5 are more concentrated, while the curves in fig. 6 are more dispersed. This shows that this disclosure embodiment provides that the vibration uniformity of each part of vibrating diaphragm is better, and in the vibration process, the rocking vibration of vibrating diaphragm is few for sound generating mechanism's tone quality and listening stability are more excellent.

Compared with engineering plastics, the diaphragm 100 provided by the present disclosure has a wider elastic region, and when the strain of the diaphragm 100 occurs in this region, after the external force is removed, the diaphragm 100 has excellent resilience. The vibrating diaphragm 100 has less swing vibration in the vibration process, so that the tone quality and listening stability of the sound generating device are better.

Fig. 7 is a harmonic distortion (THD) test curve of a diaphragm according to an embodiment of the present disclosure and a conventional PEEK diaphragm, and it can be seen from fig. 7 that the diaphragm according to the embodiment of the present disclosure has a lower THD (total harmonic distortion) compared to the conventional PEEK diaphragm. This shows that the diaphragm of this disclosure has better anti polarization ability, and tone quality is better.

Alternatively, referring to fig. 2, the diaphragm 100 includes two elastomer layers 1 and one rubber layer 2, where the rubber layer 2 is sandwiched between the two elastomer layers 1; alternatively, referring to fig. 3, the diaphragm 100 includes one layer of the elastomer layer 1 and two layers of the rubber layers 2, and the elastomer layer 1 is sandwiched between the two layers of the rubber layers 2.

Specifically, when the diaphragm 100 has one layer of the elastic body layer 1 and one layer of the rubber layer 2, that is, the structure shown in fig. 1, the diaphragm 100 can exert the sound absorption and thermal insulation effects of the elastic body layer 1 and the high elasticity and flexibility of the rubber layer 2. When it is necessary to further improve the sound absorption and thermal insulation effects of the diaphragm 100, the diaphragm 100 may include a plurality of layers of the elastic body layer 1, for example, the diaphragm 100 shown in fig. 2 includes two layers of the elastic body layer 1 and one layer of the rubber layer 2, and the rubber layer 2 is sandwiched between the two layers of the elastic body layer 1; to further improve the elasticity and flexibility of the diaphragm 100, the diaphragm 100 may include a plurality of rubber layers 2, for example, the diaphragm 100 shown in fig. 3 includes one rubber layer 1 and two rubber layers 2, and the rubber layer 1 is sandwiched between the two rubber layers 2.

It should be noted that the number of the elastomer layer containing the foamed thermoplastic elastomer and the rubber layer containing the rubber in the diaphragm of the present invention and the distribution manner between the layers are not limited thereto, and may be selected according to the requirements of the actual use performance of the diaphragm, and the present invention is not limited thereto.

Optionally, the foamed thermoplastic elastomer comprises at least one of a foamed thermoplastic polyolefin elastomer (foamed TPO), a foamed thermoplastic nylon elastomer (foamed TPAE), a foamed thermoplastic vulcanizate (foamed TPV), a foamed thermoplastic polyurethane elastomer (foamed TPU), a foamed thermoplastic polyester elastomer (foamed TPEE), and a foamed polystyrene-poly (ethylene-butylene) -polystyrene block copolymer.

Specifically, the foamed thermoplastic elastomer comprises a hard segment and a soft segment, and the hard segment and the soft segment can be connected in series or in a grafting manner. Taking the foaming TPEE as an example, the hard segment of the foaming TPEE is a polyester segment containing PBT (polybutylene terephthalate), and the soft segment of the foaming TPEE is an aliphatic polyester or polyether segment. The hard segment endows the foamed thermoplastic elastomer with good thermal property and oil and solvent resistance, and can improve the temperature resistance and corrosion resistance of the diaphragm 100; the soft segment enables the foamed thermoplastic elastomer to have lower glass transition temperature and low-temperature flexibility, so that the use temperature range of the diaphragm 100 can be increased, and the applicability of the diaphragm 100 is improved.

Optionally, the foaming conditions are chemical foaming or physical foaming.

Specifically, the chemical foaming refers to a method of foaming the foamed thermoplastic elastomer material by generating gas using a chemical method. Specifically, the foamed thermoplastic elastomer is heated to melt, a chemical foaming agent is added into the melted foamed thermoplastic elastomer to form a mixture, and the mixture is continuously heated to decompose the chemical foaming agent so as to release gas, wherein the gas forms bubbles in the forming process of the foamed thermoplastic elastomer; or, the foaming thermoplastic elastomer material is subjected to chemical reaction among different components during heating, and gas released under the chemical reaction condition is foamed in the forming process of the foaming thermoplastic elastomer material. The physical foaming is a method of introducing compressed air into the foamed thermoplastic elastomer material under the heating condition to form bubbles in the foamed thermoplastic elastomer material and on the surface of the foamed thermoplastic elastomer material in the forming process. The physical foaming does not affect the chemical properties and molecular structure of the foamed thermoplastic elastomer material, and uniform bubbles can be formed inside the foamed thermoplastic elastomer material.

Since the bubbles are uniformly distributed in the foamed thermoplastic elastomer material, that is, the bubbles are formed, the overall density of the foamed thermoplastic elastomer material is reduced, and the weight of the diaphragm 100 having the same size is reduced. This makes the resilience performance of the diaphragm 100 better, and the amplitude is larger, and the problem that the diaphragm 100 deforms due to its own weight does not occur.

Optionally, the foamed thermoplastic elastomer comprises a compact layer on the surface and a porous structure coated inside the compact layer. Specifically, the porous structure inside the foamed thermoplastic elastomer can reduce the overall density of the foamed thermoplastic elastomer material, reduce the weight of the diaphragm 100 with the same size, improve the resilience of the diaphragm 100, and control the density of the foamed thermoplastic elastomer to be 0.1g/cm³-0.9g/cm³Preferably, the density of the foamed thermoplastic elastomer may be 0.1g/cm³-0.6g/cm³. The compact layer on the surface of the foamed thermoplastic elastomer can ensure the surface flatness of the diaphragm 100 after molding, and the aesthetic appearance of the diaphragm 100 is improved.

Optionally, the glass transition temperature of the foamed thermoplastic elastomer ranges from-80 ℃ to 0 ℃, preferably from-60 ℃ to 0 ℃.

Specifically, the soft segment in the foamed thermoplastic elastomer enables the foamed thermoplastic elastomer to have a lower glass transition temperature and low-temperature flexibility, so that the use temperature range of the diaphragm 100 can be increased, and the applicability of the diaphragm 100 is improved. When the foamed thermoplastic elastomer has more soft segments, for example, the ratio of the soft segments in the foamed thermoplastic elastomer ranges from 20% to 80%, the foamed thermoplastic elastomer can have a lower glass transition temperature. The glass transition temperature of the rubber is generally lower, and when the glass transition temperatures of the foamed thermoplastic elastomer and the rubber are both in the range of-50 ℃ to 0 ℃, the diaphragm 100 can keep very good elasticity in work in an environment lower than 0 ℃, so that the sound production device can show better sound production quality. Meanwhile, the risk of damage of the diaphragm 100 in a low-temperature environment is reduced, and the reliability of the diaphragm 100 is improved.

Optionally, the thickness of the elastomer layer is in the range of 10 μm to 100 μm, preferably, the thickness of the elastomer layer may be in the range of 20 μm to 90 μm; the thickness of the rubber layer ranges from 10 to 120 μm, and preferably, the thickness of the rubber layer may range from 20 μm to 90 μm. Further, the total thickness of the diaphragm 100 is in a range of 30 to 300 μm, preferably 50 to 200 μm.

In particular, the thickness of the diaphragm 100 has a great influence on the acoustic performance of the sound generating apparatus. In general, when the thickness of the diaphragm 100 is relatively low, although the sensitivity of the diaphragm 100 can be improved, the reliability of the diaphragm 100 is reduced; when the thickness of the diaphragm 100 is larger, although the reliability of the diaphragm 100 can be improved, the sensitivity of the diaphragm 100 is reduced. The thickness of the diaphragm 100 is controlled within a range of 30 μm to 300 μm, preferably 50 μm to 200 μm, and on the basis of ensuring the reliability of the diaphragm 100, that is, the elastic performance and the rigidity of the diaphragm 100 can both meet the manufacturing requirements of a sound generating device, so that the service life of the diaphragm 100 is ensured, and the sensitivity of the diaphragm 100 is improved.

Optionally, the rubber layer includes at least one of Natural Rubber (NR), styrene-butadiene rubber (SBR), Butadiene Rubber (BR), Isoprene Rubber (IR), Chloroprene Rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), chlorinated nitrile rubber (HNBR), ethylene propylene rubber (EPDM), silicone rubber (Q), fluorine rubber (FPM), polyurethane rubber (AU), acrylate rubber (ACM), chlorosulfonated polyethylene rubber (CSM), epichlorohydrin rubber (CO), polysulfide rubber, and ethylene-vinyl acetate rubber. Specifically, the rubber has high elasticity and flexibility, and can ensure the vibration sensitivity of the diaphragm 100.

Optionally, the shore hardness of the diaphragm 100 is in a range of 25A to 90A, and preferably, the shore hardness of the diaphragm 100 may be in a range of 35A to 80A.

Specifically, the resonant frequency F0 of the sound generating device is proportional to the modulus and thickness of the diaphragm. And for the composite diaphragm, the modulus is proportional to the hardness. Therefore, the modulus of the diaphragm 100 may be embodied by stiffness. The higher the material strength and stiffness of the diaphragm 100, the higher the F0 of the diaphragm material, resulting in a reduced loudness and a poor bass sound of the sound generating apparatus. Fig. 4 shows the F0 curve for a sound generator with diaphragms of the same thickness but different stiffness, and it can be seen from fig. 4 that as the stiffness of the diaphragm material increases, the F0 of the sound generator increases sharply.

The vibrating diaphragm for the sound production device provided by the disclosure can be a corrugated diaphragm or a flat-plate vibrating diaphragm. The resonant frequency F0 of this sound generating mechanism is directly proportional to the Young's modulus and the thickness of vibrating diaphragm, can realize F0's change through the thickness and the Young's modulus of change vibrating diaphragm, and the concrete theory of regulation is as follows:

wherein Mms is the equivalent vibration mass of the sounding device, Cms is the equivalent compliance of the sounding device:

wherein, C_m1For compliance with the elastic wave, C_m2The diaphragm compliance is achieved. When there is no elastic wave design, the equivalent compliance of the sounding device is the compliance of the vibrating diaphragm:

wherein W is the total width of the bending ring part of the diaphragm, and t is the thickness of the diaphragm; dvc is the joint outer diameter of the vibrating diaphragm and the voice coil; e is the Young modulus of the vibrating diaphragm material; a is₁And a₂To correct the coefficient, a₁The value of (a) depends on the shape of the diaphragm substrate₂Equal to h (edge height)/W; u is the Poisson's ratio of the vibrating diaphragm material.

It can be seen that to obtain a full bass and comfortable hearing, the diaphragm should have sufficient stiffness and damping while the sound generator has a low F0. The size of F0 can be adjusted by one skilled in the art by adjusting the stiffness and thickness of the diaphragm. Preferably, the shore hardness of the diaphragm 100 is preferably 35A-80A. The thickness of the diaphragm 100 is 50 μm to 200 μm. This enables the resonance frequency F0 of the sound generating device to reach 150Hz-1500 Hz. The low-frequency performance of the sound production device is excellent.

Fig. 8 is a test curve of loudness at different frequencies (SPL curve) for a diaphragm of one embodiment of the present disclosure and a conventional diaphragm. The vibrating diaphragm is a corrugated ring vibrating diaphragm. The abscissa is frequency (Hz) and the ordinate is loudness.

As can be seen from fig. 8, the mid-frequency performance of the diaphragms of the two sound generators is close. However, the sound generating device F0 of the diaphragm in the embodiment of the present disclosure is 834Hz, as shown at a in fig. 8; the sound generator F0 for a conventional diaphragm is 929Hz, as shown at b in fig. 8. This shows that the low frequency sensitivity of the diaphragm in this embodiment is higher than that of the conventional diaphragm. That is to say, the sound generating device that adopts the vibrating diaphragm of this disclosed embodiment has higher loudness and comfort level.

The present disclosure also provides a sound generating device, including the sound generating device main part with the vibrating diaphragm, vibrating diaphragm 100 sets up in the sound generating device main part, vibrating diaphragm 100 is configured to can vibrate the sound production, and then produces sound through the vibration. The sound generating device body may be configured with a coil, a magnetic circuit system, and other components, and the diaphragm 100 is driven to vibrate by electromagnetic induction.

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

Claims

1. A diaphragm for a sound-emitting device, wherein the diaphragm includes at least one elastomer layer including a foamed thermoplastic elastomer obtained under a foaming condition for the thermoplastic elastomer and at least one rubber layer including rubber, and the foamed thermoplastic elastomer has cells including at least one of closed cells and open cells.

2. The diaphragm of claim 1, wherein the diaphragm includes two elastomer layers and one rubber layer, and the rubber layer is sandwiched between the two elastomer layers;

3. The diaphragm of claim 1 wherein the foamed thermoplastic elastomer comprises at least one of a foamed thermoplastic polyolefin elastomer, a foamed thermoplastic nylon elastomer, a foamed thermoplastic vulcanizate, a foamed thermoplastic polyurethane elastomer, a foamed thermoplastic polyester elastomer, and a foamed polystyrene-poly (ethylene-butylene) -polystyrene block copolymer.

4. The diaphragm of claim 1 wherein the foaming condition is chemical foaming or physical foaming.

5. The diaphragm of claim 1, wherein the pore size of the pores is in the range of 0.1 μm to 70 μm.

6. The diaphragm of claim 1 wherein the foamed thermoplastic elastomer has a density in the range of 0.1g/cm³-0.9g/cm³。

7. The diaphragm of claim 1 wherein the foamed thermoplastic elastomer has a glass transition temperature in the range of-80 ℃ to 0 ℃.

8. The diaphragm of claim 1, wherein the thickness of the elastomer layer is in a range of 10 μm to 100 μm; the thickness range of the rubber layer is 10-120 mu m.

9. The diaphragm of claim 8 wherein the diaphragm has an overall thickness in the range of 30 μm to 300 μm.

10. The diaphragm of claim 1 wherein the rubber layer comprises at least one of Natural Rubber (NR), styrene-butadiene rubber (SBR), Butadiene Rubber (BR), Isoprene Rubber (IR), Chloroprene Rubber (CR), butyl rubber (IIR), nitrile rubber (NBR), chlorinated nitrile rubber (HNBR), ethylene propylene rubber (EPDM), silicone rubber (Q), fluoro rubber (FPM), urethane rubber (AU), acrylate rubber (ACM), chlorosulfonated polyethylene rubber (CSM), epichlorohydrin rubber (CO), polysulfide rubber, and ethylene-vinyl acetate rubber.

11. The diaphragm of claim 1, wherein the diaphragm has a shore hardness in a range of 25A to 90A.

12. A sound-generating device comprising a sound-generating device main body and the diaphragm of any one of claims 1 to 11, wherein the diaphragm is disposed on the sound-generating device main body.