CN111534058A

CN111534058A - Acoustic adjusting material, filling method, sound production device and electronic equipment

Info

Publication number: CN111534058A
Application number: CN202010660089.XA
Authority: CN
Inventors: 潘泉泉; 姚阳阳; 凌风光; 李春; 刘春发
Original assignee: Goertek Inc
Current assignee: Goertek Inc
Priority date: 2020-07-10
Filing date: 2020-07-10
Publication date: 2020-08-14
Also published as: WO2022007333A1

Abstract

The invention discloses an acoustic adjusting material, a sound production device, a filling method and electronic equipment. The acoustic conditioning material includes: the acoustic improvement filler comprises an expandable thermoplastic elastomer filler and an acoustic improvement filler, wherein the expandable thermoplastic elastomer filler is foamed under a triggered condition to form a foam filler so as to provide a buffer effect for the acoustic improvement filler when the acoustic improvement filler is collided in a moving mode, and the volume of the expanded expandable thermoplastic elastomer filler is changed along with the change of temperature and/or foaming time. In this way, the risk of breaking the acoustic improvement filler is greatly reduced, and the durability and the service life of the acoustic adjusting material are improved.

Description

Acoustic adjusting material, filling method, sound production device and electronic equipment

Technical Field

The invention relates to the technical field of electroacoustic conversion, in particular to an acoustic adjusting material of a sound generating device, a filling method, the sound generating device and electronic equipment.

Background

A sound generating device, such as a receiver or a speaker, generally includes a housing, and a sound generating unit accommodated in the housing. The sound production monomer divides the cavity in the shell into a front sound cavity and a rear sound cavity. The front sound cavity is communicated with the sound outlet, and sound waves generated by the sound generating monomer are radiated from the front sound cavity. The back sound cavity is communicated with the sound production monomer. The vibrating air flow on the opposite side of the sound wave can radiate into the rear sound cavity. The back sound cavity is used for adjusting the low-frequency effect of the sound generating device.

For better tuning of the low frequency effect, the rear sound cavity is typically filled with sound absorbing particles. Inhale the sound granule can adsorb, desorption vibration gas to make sound generating mechanism's low frequency effect better.

However, during operation, the sound-absorbing particles may collide with each other, resulting in breakage. On the one hand, the breakage can produce the dust, and the dust gets into the sound production monomer, can cause the sound production monomer abnormal operation. On the other hand, sound absorbing particle breakage will raise the F0 of the sound generating device, causing the low frequency effect to be poor.

Chinese utility model patent ZL201921855579.4 discloses a filler for speaker, this filler includes expandable filler and acoustics filler, and wherein expandable filler can be when the inflation triggers from first size permanent inflation to second size, plays the fixed action to acoustics filler, improves the sound quality of equidirectional to can reduce the removal of acoustics filler, so as not to produce and flow and make an uproar (0007 section). However, when triggered by expansion, the expandable filler is permanently expanded from an initial first size to a fixed second size, the size of the expandable filler is not changed any more, and the expansion degree of the expandable filler cannot be effectively adjusted according to different use environmental conditions, so that the applicability of the expandable filler is reduced.

Therefore, a new technical solution is needed to solve the above technical problems.

Disclosure of Invention

An object of the present invention is to provide a new technical solution for an acoustic conditioning material of a sound emitting device.

According to a first aspect of the present invention, there is provided an acoustic conditioning material. The acoustic conditioning material includes: an expandable thermoplastic elastomer padding that expands under triggered conditions into a foam padding to dampen the movement of the acoustic improvement padding, and an acoustic improvement padding, the volume of the expandable thermoplastic elastomer padding after expansion varying with temperature and/or expansion time. Optionally, the expandable thermoplastic elastomer filler is in the class of one or more of polyolefin thermoplastic elastomers, thermoplastic vulcanizates, thermoplastic polyurethane elastomers, thermoplastic polyester elastomers, and styrenic block copolymers. .

Optionally, the acoustic improvement filler is a material with acoustic properties made of one or more of activated carbon, zeolite powder, silica, porous alumina, molecular sieves, metal-organic framework materials.

Optionally, the expandable thermoplastic elastomer filler is in the form of particles, flakes or blocks.

Optionally, the expandable thermoplastic elastomer filler has a density of 0.005g/mL to 0.8g/mL after foaming.

Optionally, the expandable thermoplastic elastomer filler is in the form of particles, and after expansion, the expandable thermoplastic elastomer filler has a physical size of 0.1mm to 23 mm.

Optionally, the expandable thermoplastic elastomer filler comprises a thermoplastic elastomer material and a blowing agent mixed together, wherein the blowing agent comprises a low boiling alkane or the like.

Optionally, the expandable thermoplastic elastomer filler is triggered by at least one of thermal radiation, optical radiation, electromagnetic radiation.

Optionally, before foaming, the expandable thermoplastic elastomer filler accounts for 0.01% -40% of the total volume of the acoustic conditioning material; after foaming, the volume of the foam filler accounts for 0.05-65% of the total volume of the acoustic conditioning material.

Optionally, before foaming, the expandable thermoplastic elastomer filler accounts for 0.1% -20% of the total volume of the acoustic conditioning material; after foaming, the volume of the foam filler is 5% -60% of the total volume of the acoustic conditioning material.

Optionally, the acoustic enhancement filler is cushioned by a foam filler formed from the expandable thermoplastic elastomer filler after foaming.

Optionally, the expandable thermoplastic elastomer filler is triggered by a physical foaming process or a chemical foaming process.

Optionally, the expandable thermoplastic elastomer filler increases in volume by a factor of 2 to 140 after foaming.

Optionally, the volume of the expandable thermoplastic elastomer filler increases by a factor of 3 to 110 after foaming.

Optionally, the foaming process of the expandable thermoplastic elastomer filler comprises a first foaming stage and a second foaming stage, the first foaming stage resulting in a first foam cushion filler, the second foaming stage resulting in a second foam cushion filler.

Optionally, the volume of the second foam cushion filler is 1-25 times the volume of the first foam cushion filler. According to a second aspect of the present disclosure, a sound emitting device is provided. This sound generating mechanism includes casing, sound production monomer and foretell acoustics adjusting material, the inside formation cavity of casing, the cavity includes back vocal cavity, sound production monomer sets up in the cavity, sound production monomer with back vocal cavity intercommunication, back vocal cavity includes the filling district, acoustics adjusting material sets up in the filling district.

Optionally, the acoustic conditioning material has a fill rate of 50% -95% in the filling zone prior to foaming.

Optionally, the expandable thermoplastic elastomer filler and the acoustic enhancement filler are both particulate materials,

the expandable thermoplastic elastomer filler is mixed with the acoustic improvement filler and filled in the filling area.

Optionally, the expandable thermoplastic elastomer filler and the acoustic enhancement filler are both bulk materials,

the expandable thermoplastic elastomer filler is arranged alternately with the acoustic improvement filler; or the expandable thermoplastic elastomer filler and the acoustic improvement filler in the block shape in the same layer are distributed in an array, and the expandable thermoplastic elastomer filler and the acoustic improvement filler are arranged in an interlaced manner.

Optionally, the expandable thermoplastic elastomer filler forms a lattice structure, and the acoustic improvement filler is filled in gaps formed by the expandable thermoplastic elastomer filler; or the acoustic improvement filler forms a lattice structure, and the expandable thermoplastic elastomer filler is filled in gaps formed by the acoustic improvement filler.

According to a third aspect of the present disclosure, there is provided a filling method of an acoustic conditioning material of a sound emitting device. The acoustic conditioning material is disposed within the filling area of the rear acoustic cavity of the sound generating device in any of the following ways:

the acoustic adjusting material is granular, and the filling area is filled with the expandable thermoplastic elastomer filling material and then filled with the acoustic improving filling material;

the acoustic adjusting material is granular, and firstly, acoustic improving filler is filled into the filling area, and then expandable thermoplastic elastomer filler is filled into the filling area;

the acoustic adjusting material is granular, the expandable thermoplastic elastomer filler and the acoustic improving filler are mixed firstly, and then the mixed expandable thermoplastic elastomer filler and the acoustic improving filler are filled into the filling area;

an expandable thermoplastic elastomer filler is first arranged in at least one wall portion of the filling zone to form an expandable thermoplastic elastomer filler layer, and then an acoustically improving filler is filled into the filling zone.

According to a fourth aspect of the present disclosure, an electronic device is provided. The electronic equipment comprises the sound generating device.

According to one embodiment of the present disclosure, the acoustic conditioning material includes an expandable thermoplastic elastomer filler and an acoustic improvement filler. Upon being triggered, the expandable thermoplastic elastomer filler foams, becoming a foam that provides a cushioning effect to acoustically improve the flow, impact of the filler. In the working process of the sound generating device, the expandable thermoplastic elastomer filler greatly reduces the risk of breaking the filler in an acoustic improvement manner, and improves the durability and the service life of the acoustic adjusting material.

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

Drawings

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

Fig. 1 is a schematic illustration of a particulate acoustic conditioning material in an unfoamed state according to an embodiment of the disclosure.

Fig. 2 is a schematic view of a foaming state of a particulate acoustic adjusting material according to an embodiment of the present disclosure.

Fig. 3 is a schematic view of a bulk acoustic conditioning material in an unfoamed state according to an embodiment of the disclosure.

Fig. 4 is a schematic view of a foaming state of a bulk acoustic adjusting material according to an embodiment of the present disclosure.

Fig. 5 is a schematic diagram of an unfoamed state of an array of distributed bulk acoustic conditioning material according to an embodiment of the disclosure.

Fig. 6 is a schematic illustration of an unfilled state of a grille-structure acoustic conditioning material in accordance with an embodiment of the present disclosure.

Description of reference numerals:

11: a housing; 12: a sounding monomer; 13: a gap; 14: an expandable thermoplastic elastomer filler; 15: an acoustic improving filler; 16: the posterior acoustic chamber.

Detailed Description

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

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

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

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

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

According to one embodiment of the present disclosure, an acoustic conditioning material for a sound generating device is provided. As shown in fig. 1 to 2, the acoustic conditioning material includes: an expandable thermoplastic elastomer filler 14 and an acoustic improving filler 15. The expandable thermoplastic elastomer padding 14 is foamed under triggered conditions into a foam padding to dampen the movement of the acoustic enhancement padding 15, the volume of the expandable thermoplastic elastomer padding 14 foaming varying with temperature and/or with foaming time.

The degree of cushioning of the expandable thermoplastic elastomer filler 14 upon a moving impact can be flexibly controlled by the temperature and time of its foaming. When the expandable thermoplastic elastomer filler 14 is expanded, the temperature increases, the damping of the expandable thermoplastic elastomer filler 14 increases, and the cushioning ability of the expandable thermoplastic elastomer filler 14 increases. The higher the temperature is, the larger the volume of the foam cushion filler is in a set time; the longer the foaming time, the greater the volume of foam cushion at a given temperature.

When the sound generating device is impacted by external force, the foam filler provides buffer force for the flow and collision of the acoustic improvement filler, and the collision probability of the acoustic improvement filler is reduced. In this way, the risk of breaking the acoustic improvement filler is greatly reduced, and the durability and the service life of the acoustic adjusting material are improved.

The expandable thermoplastic elastomer filler 14 refers to a thermoplastic elastomer material that can be expanded under a set trigger condition. In the non-triggered condition, expandable thermoplastic elastomer filler 14 has a smaller volume. This allows the material to be easily filled into a defined cavity, for example the filling area of the rear acoustic cavity. The material foams under a triggered condition, thereby providing cushioning for the acoustically improved padding when impacted.

The expandable thermoplastic elastomer filler is one or more of polyolefin thermoplastic elastomer, thermoplastic vulcanizate, thermoplastic polyurethane elastomer, thermoplastic polyester elastomer and styrene block copolymer. The materials can be triggered under the condition of heat radiation, so that the foaming is realized. And, under different trigger temperatures, the foamed volume is different, and changes with the temperature change in the application process.

The acoustically improving filler 15 means a porous material capable of adsorbing and desorbing the vibrating gas. For example, the acoustic adjusting material includes an acoustic performance material made of one or more of activated carbon, zeolite powder, silica, porous alumina, molecular sieve, metal-organic framework material, and the like. The acoustic improvement filler 15 may be in the form of particles, flakes, blocks, or the like.

Optionally, the expandable thermoplastic elastomer filler is spherical, spheroidal, rod-like, cylindrical, square or radial. The filling effect of the shape is good, and the filling rate is high.

In the disclosed embodiment, the acoustic conditioning material includes an expandable thermoplastic elastomer filler 14 and an acoustic improvement filler 15. The expandable thermoplastic elastomer padding 14 is foamed under triggered conditions into foam padding to dampen the movement of the acoustic enhancement padding 15. The acoustic enhancement filler 15 is less likely to collide during operation of the sound generating apparatus. In this way, the expandable thermoplastic elastomer filler 14 greatly reduces the risk of breakage of the acoustic enhancement filler 15, increasing the durability and service life of the acoustic conditioning material.

Further, the expandable thermoplastic elastomer filler 14 forms cells after being expanded. The expandable thermoplastic elastomer material has elasticity, and the cells can change their volume according to the change of the external pressure, thereby providing a buffering action to the movement of the acoustic improving filler 15. In this way, the expandable thermoplastic elastomer filler 14 can effectively buffer the flow, impact of the acoustic improvement filler 15.

In particular, the expandable thermoplastic elastomer filler 14 effectively dampens the vibrations of the acoustic conditioning material when the sound generating device is operated at high power.

In addition, when the sound generating device is impacted by external force, the cells provide buffering force for the acoustic improvement filler 15, and gas in the cells is subjected to stagnation and compression, so that external energy is consumed and dissipated. The cells gradually terminate the impact load with a small negative acceleration, and therefore, the expandable thermoplastic elastomer filler 14 has a good shock-proof effect.

In addition, the different triggering temperatures enable the expandable thermoplastic elastomer filler 14 to change the volume of foaming so as to adapt to different application environments, and therefore the acoustic conditioning material has stronger weather resistance and adaptability.

Optionally, the expandable thermoplastic elastomer filler is triggered by a physical foaming process or a chemical foaming process. The physical foaming method is as follows: a method for foaming a thermoplastic elastomer by a volatile component of the thermoplastic elastomer or a volatile component dispersed in the thermoplastic elastomer during molding.

For example, the physical foaming method may be a method in which an inert gas is dissolved in a thermoplastic elastomer under a predetermined pressure, and then the gas is released by a pressure reduction method, thereby forming bubbles in the thermoplastic elastomer.

Alternatively, the low boiling point alkane may be added to the thermoplastic elastomer, and then the heating may be performed to volatilize the low boiling point alkane, thereby forming bubbles in the thermoplastic elastomer. The low boiling alkane includes at least one of petroleum ether, butane, pentane, etc. These materials are all capable of volatilizing under heat, thereby forming bubbles within the thermoplastic elastomer. The plurality of bubbles forms a foam.

The chemical foaming method is as follows: the thermoplastic elastomer is foamed by chemically generating a gas: the chemical foaming agent added to the thermoplastic elastomer is heated to decompose and release gas to foam. Among them, the foaming agent may be, but not limited to, ammonium carbonate, sodium bicarbonate, ammonium chloride, urea, and the like. The foaming agent is decomposed under heating to generate a gas, thereby forming bubbles in the thermoplastic elastomer.

The foaming may be carried out by using a gas released by a chemical reaction between the components of the thermoplastic elastomer.

The volume of expansion is different under different trigger conditions. For example, the higher the trigger temperature, the greater the volume expansion, and the lower the trigger temperature, the less the volume expansion. The greater the concentration of blowing agent, the greater the volume expansion; the smaller the concentration of the blowing agent, the smaller the volume expansion.

In one example, the expandable thermoplastic elastomer filler 14 includes an expandable thermoplastic elastomer material and a blowing agent mixed together, wherein the blowing agent includes a low boiling alkane. For example, low boiling alkanes have a boiling point of 30 ℃ to 40 ℃. In the preparation process, the thermoplastic elastomer material and the foaming agent are mixed together in a high-pressure reaction kettle. The process is simple and the expandable thermoplastic elastomer filler 14 can be formed by one reaction.

It is also possible to add a foaming agent to the expandable thermoplastic elastomer material, so that the foaming agent penetrates into the expandable thermoplastic elastomer material.

The low boiling alkane includes at least one of petroleum ether, butane, pentane, etc. These materials are all capable of volatilizing under a set trigger condition to form cells within the expandable thermoplastic elastomer material. The plurality of cells form a foam.

Of course, the kind of the foaming agent is not limited to the above examples, and those skilled in the art can select the foaming agent according to actual needs.

In one example, the expandable thermoplastic elastomer filler 14 is at least one of an expandable TPEE, an expandable TPU, or other high molecular polymer. The expandable thermoplastic elastomer filler 14 is capable of foaming in volume under a set trigger condition, thereby damping the movement of the acoustic improvement filler 15.

For example, expandable TPEE comprises TPEE and a blowing agent mixed together.

The expandable TPEE filler has the characteristics of light weight, no water absorption, ageing resistance, strong corrosion performance, strong toughness, no toxicity and no pollution.

The kind, amount and the like of the foaming agent can be selected by those skilled in the art according to actual needs.

In one example, the expandable thermoplastic elastomer filler 14 is in the form of particles or sheets. These materials have good fluidity and can be easily filled in a cavity.

The filling zone of the rear acoustic cavity 16 of the sound-emitting device can be filled directly with the expandable thermoplastic elastomer filling 14 in the form of granules or flakes.

It is also possible to prepare the expandable thermoplastic elastomer filler 14 in the form of particles or sheets into a predetermined shape and fill the filling region of the rear sound chamber 16 of the sound generating device.

It is also possible that one of the expandable thermoplastic elastomer filler 14 and the acoustic improvement filler 15 is prepared in a set three-dimensional structure, and the other is filled in the gaps of the three-dimensional structure in a granular or sheet form.

In one example, the expandable thermoplastic elastomer filler 14 is in particulate form. After foaming, the expandable thermoplastic elastomer filler 14 has a physical size of 0.1mm to 25 mm.

Within this size range, the cushioning effect of the expandable thermoplastic elastomer filler 14 to the acoustic improving filler 15 is good, and the cushioning effect of the cells is good.

In addition, the particles are moderate in size, the airflow channel of the acoustic improvement filler 15 cannot be blocked, and the adsorption and desorption effects of the acoustic adjusting material on the vibrating airflow are good.

Further, the expandable thermoplastic elastomer filler is in the form of particles, and after being expanded, the expandable thermoplastic elastomer filler 14 has a physical size of 0.5mm to 2 mm. In this range, the cushioning effect of the acoustic improving filler by the expandable thermoplastic elastomer filler 14 forming cells is more excellent.

In one example, the expandable thermoplastic elastomer filler 14 has a density of 0.2g/mL to 1.5g/mL when the acoustic enhancement filler is unfoamed. In this density range, the density of the entirety of the acoustic conditioning material is small, which makes the weight of the entirety of the sound emitting device light.

Preferably, the expandable thermoplastic elastomer filler 14 has a density of 0.5g/mL to 1.2g/mL, within which the acoustic conditioning material has little effect on the overall weight of the sound emitting device.

In one example, the expandable thermoplastic elastomer filler has a density of 0.005g/mL to 0.8g/mL after foaming. Within this range, the foam padding has good cushioning effect on the acoustic improvement padding, high structural strength, and good durability.

Preferably, the expandable thermoplastic elastomer filler has a density of 0.01g/mL to 0.08 g/mL. Within this range, the cushioning effect of the foam padding on the acoustic improvement padding is more excellent.

In one example, the expandable thermoplastic elastomer filler 14 is triggered by at least one of thermal radiation, optical radiation, electromagnetic radiation. Under the above irradiation conditions, the foaming agent in the expandable thermoplastic elastomer filler 14 volatilizes and becomes large in volume, forming cells in the expandable thermoplastic elastomer material, thereby causing the expansion of the expandable thermoplastic elastomer material.

Under the same temperature condition, the volume of the expandable thermoplastic elastomer filler 14 can be increased to an appropriate value under a certain trigger time, and if the trigger time is too short, the expansion ratio of the expandable thermoplastic elastomer filler 14 is small, and the function of buffering the acoustic improvement filler 15 is not achieved.

At the same trigger time and at a certain trigger temperature, the volume of the expandable thermoplastic elastomer filler 14 can be increased to an appropriate value, and cell breakage occurs more easily at higher temperatures; conversely, the lower the trigger temperature, the smaller the foaming volume of the expandable thermoplastic elastomer filler 14, and the less the function as the buffering acoustic improvement filler 15.

In addition, the cells within the expandable thermoplastic elastomer filler 14 are not broken.

The blowing agent in the expandable thermoplastic elastomer filler 14 is triggered by means of ultraviolet radiation when subjected to light radiation. The foaming agent becomes larger in volume under heated conditions, thereby forming cells in the expandable thermoplastic elastomer filler.

When electromagnetic radiation is applied, the acoustic conditioning material is heated under the influence of the alternating magnetic field. The foaming agent volatilizes, thereby forming cells within the expandable thermoplastic elastomer filler 14.

The triggering mode is simple to operate, and the controllability of the size of the foam holes is strong.

Of course, the triggering mode of the expandable thermoplastic elastomer filler 14 is not limited to the above-described embodiment, and those skilled in the art can select the triggering mode according to actual needs.

In one example, the expandable thermoplastic elastomer filler comprises 0.01% to 40% of the total volume of the acoustic conditioning material prior to foaming; after foaming, the expandable thermoplastic elastomer filler 14 accounts for 0.05-65% of the volume of the acoustic adjusting material.

Before foaming, the proportion of the acoustic improvement filler is large in the proportion range, and the acoustic improvement filler can be uniformly dispersed in the cavity.

The larger the proportion of the expandable thermoplastic elastomer filler 14 in the acoustic adjusting material is, the smaller the filling amount of the acoustic improving filler 15 is, and the effects of adsorption and desorption of vibration gas of the acoustic adjusting material are reduced; conversely, the smaller the proportion of the expandable thermoplastic elastomer filler 14 in the acoustic adjusting material, the less the effect of cushioning is exerted.

In the above-mentioned volume ratio range, although the filling amount of the acoustic improvement filler 15 is relatively reduced, the expandable thermoplastic elastomer filler 14 can form channels after foaming, so that the vibration gas can easily enter and exit the acoustic adjusting material, and the sound absorbing effect of the acoustic adjusting material is remarkably improved.

The shape retention effect of the acoustic improving filler 15 is good and the durability is good due to the cushioning effect of the expandable thermoplastic elastomer filler 14.

Further, before foaming, the expandable thermoplastic elastomer filler accounts for 0.1% -20% of the total volume of the acoustic adjusting material; after foaming, the volume of the foam filler is 5% -60% of the total volume of the acoustic conditioning material. Within this range, the sound absorbing effect of the acoustic adjusting material is more excellent and the durability is excellent.

In one example, the expandable thermoplastic elastomer filler 14 comprises 0.1% to 20% by mass of the total mass of the acoustic conditioning material. Within this range, a higher filling rate in the cavity can be achieved with less expandable thermoplastic elastomer filler 14.

In addition, the mass ratio of the expandable thermoplastic elastomer filler 14 is low, so that the effect of the acoustic adjusting material in adsorbing and desorbing the vibrating gas is not affected.

Further, the expandable thermoplastic elastomer filler 14 accounts for 1% to 5% by mass of the total mass of the acoustic adjusting material. Within this range, the acoustic adjusting material has good durability and good effects of adsorbing and desorbing the vibrating gas.

In a particular example, the process of foaming the expandable thermoplastic elastomer padding 14 comprises a first foaming stage resulting in a first foam padding and a second foaming stage resulting in a second foam padding. The cushioning effect of the expandable thermoplastic elastomer filler 14 can be flexibly controlled by the stage foaming of the expandable thermoplastic elastomer filler 14.

Under the triggering condition, the expandable thermoplastic elastomer 14 expands in different volumes with different temperatures and/or expansion times. In application after foaming, the first foam cushion filler is subjected to a second stage foaming process along with the change of the use temperature, and the foaming volume is different along with different temperatures and/or foaming time in the second stage foaming process. After foaming, the first foam cushion filling has a certain inhibiting effect on the acoustic improvement effect, because it occupies the back cavity volume.

Therefore, at the initial stage of filling, the expandable thermoplastic elastomer 14 is subjected to the first stage foaming, and the first foam cushion filler provides a certain cushion effect. In the practical application process, if meet sound generating mechanism high power operation under the high temperature environment, when sound generating mechanism is in high power operation, the gluing agent that the filler was improved to acoustics can be ageing, and intensity variation, and the filler is improved to acoustics is broken easily. Under the condition, the expandable thermoplastic elastomer 14 is easier to continue to expand, the damping characteristic of the surface of the first foam buffer filler is further improved, and the buffer is provided for the collision of the acoustic improvement filler, so that the crushing of the acoustic improvement filler is reduced.

Even under normal circumstances, the adhesive of the acoustic improving filler slowly ages with time, resulting in a decrease in strength. In the process, the volume of the first foam buffering filler is slowly changed, the surface damping characteristic is increased, the buffering capacity is enhanced, and under the condition, the expandable thermoplastic elastomer 14 can be subjected to foaming change at the second stage, so that the damping is enhanced, the buffering effect is improved, and the fragile phenomenon caused by poor strength of the acoustic improvement filler is effectively avoided.

Specifically, referring to table 1, the volume of the expandable thermoplastic elastomer filler 14 after foaming varies with the foaming temperature and/or the foaming time, and the damping of the expandable thermoplastic elastomer filler increases when the temperature rises in a certain temperature range, and the buffering capacity of the expandable thermoplastic elastomer filler is enhanced; the damping of the expandable thermoplastic elastomer filler increases over time and the cushioning capacity of the expandable thermoplastic elastomer filler increases over a range of temperatures. Therefore, the degree of foaming of the expandable thermoplastic elastomer filler 14 can be controlled by the foaming temperature and/or the foaming time.

TABLE 1 volume as a function of temperature data for the first foaming stage of expandable materials

When the expandable thermoplastic elastomer filler 14 is applied to the sound-emitting device, if the expandable thermoplastic elastomer filler 14 has been expanded to the maximum expanded volume, the strength of the acoustic improvement filler 15 may be weakened during long-term use at high temperature, and there is still a risk of breakage. If the expandable thermoplastic elastomer filler 14 is subjected to the first foaming stage to obtain the first foam filler, and the first foam filler is not foamed to the maximum foaming volume, the expandable thermoplastic elastomer filler 14 is applied to the sound generating device, and in the long-term high-temperature use process of the sound generating device, the expandable thermoplastic elastomer filler 14 is subjected to the second foaming stage at high temperature, so that the expandable thermoplastic elastomer filler 14 can be foamed continuously, the volume of the expandable thermoplastic elastomer filler 14 is increased, and then the acoustic improvement filler 15 can be further buffered, and the service life of the acoustic improvement filler 15 is ensured.

The expandable thermoplastic elastomer filling 14 may frequently undergo a plurality of high-temperature foaming processes during a long-term high-frequency use of the sound emitting device, and therefore, the second foaming stage herein refers not only to one foaming stage but also to a plurality of foaming stages. For example, when the sound generating device is operated for a long time and at a high power, the interior of the sound generating device generates a high temperature, and at this time, the expandable thermoplastic elastomer filler 14 can be subjected to a foaming stage, and when the sound generating device is operated for a plurality of times for a long time and at a high power, the expandable thermoplastic elastomer filler 14 undergoes a plurality of foaming processes.

Optionally, the volume of the second foam padding is 1-25 times the volume of the first foam padding.

Specifically, if the maximum foaming volume is not reached after the expandable thermoplastic elastomer filler 14 has been subjected to the first stage foaming, the volume of the expandable thermoplastic elastomer filler 14 after continuing the second stage foaming may be further increased.

In a specific embodiment, referring to Table 2, the expandable thermoplastic elastomer filler 14 has a volume of expansion that increases with increasing temperature in the range of 80 to 100 DEG C

TABLE 2 volume as a function of temperature data for the second foaming stage of the expandable Material

Specifically, the physical size of the expandable thermoplastic elastomer filler 14 may be comparable to the physical size of the acoustic improving filler 15 before foaming, which facilitates uniform mixing of the expandable thermoplastic elastomer filler 14 and the acoustic improving filler 15; it is also possible that the physical size of the expandable thermoplastic elastomer filler 14 is larger or smaller than that of the acoustic improving filler 15, which facilitates the increase in the filling amount of the acoustic adjusting material. After foaming, the expandable thermoplastic elastomer filler 14 has a significantly increased volume and a significantly reduced density, which can provide a significant cushioning effect to the acoustic enhancement filler 15 during a moving collision.

According to another embodiment of the present disclosure, a sound generating device is provided. The sound generating device comprises a shell 11, a sound generating unit 12 and the sound adjusting material of the sound generating device provided by the disclosure. The interior of the housing 11 forms a cavity. The cavity comprises a rear acoustic cavity 16. The rear acoustic chamber 16 includes a filling section. The filling area may be the entire rear acoustic chamber 16 or may be a portion of the rear acoustic chamber 16. The sound generating unit 12 is arranged in the cavity. The sound generating unit 12 is communicated with the rear sound cavity 16. The acoustic conditioning material is disposed within the filling zone.

The sound production device has the characteristics of good sound production effect, good low-frequency effect and good durability.

In one example, the filling rate of the acoustic conditioning material in the filling zone is 55% -95% without being triggered. Within this ratio range, the foaming of the expandable thermoplastic elastomer filler 14 provides a cushioning effect against the flow and impact of the acoustically improved filler.

Preferably, the filling rate of the acoustic conditioning material in the filling zone is 60% to 85% in the non-triggered condition. Within the range, after being triggered, the acoustic adjusting material can better play a buffering role, can provide buffering for the flowing and collision of the acoustic improving filler, and prevents the acoustic improving filler from being broken.

In one example, as shown in fig. 3-4, both the expandable thermoplastic elastomer filler 14 and the acoustic improvement filler 15 are bulk materials. The expandable thermoplastic elastomer filler 14 is arranged alternately with the acoustic improving filler 15. In this example, the expandable thermoplastic elastomer filler 14 can effectively press the acoustic improvement filler 15 in the direction of arrangement of the two fillers, thereby enabling the acoustic improvement filler 15 to effectively cushion.

In one example, as shown in fig. 5, the expandable thermoplastic elastomer filler 14 and the acoustic improvement filler 15 in the form of blocks in the same layer are distributed in an array, and the expandable thermoplastic elastomer filler 14 and the acoustic improvement filler 15 are arranged alternately.

In this example, in the foamed state, the expandable thermoplastic elastomer filler 14 can effectively press the acoustic improvement filler 15 in all directions of the same layer, thereby effectively damping the movement of the acoustic improvement filler 15.

In one example, as shown in fig. 6, the expandable thermoplastic elastomer filler 14 forms a lattice structure. The acoustic improvement filler 15 is filled in the gap 13 formed by the expandable thermoplastic elastomer filler 14.

Alternatively, the acoustic improvement filler 15 forms a lattice structure. The expandable thermoplastic elastomer filler 14 is filled in the gap 13 formed by the acoustic improvement filler 15.

For example, the grid cells of the grid structure are rectangular, circular, oval, triangular, or rhombic, etc. The grating structure makes the structure of the acoustic adjusting material regular, and the stability and consistency of the adsorption and desorption vibration gas are good.

During filling, the housing 11 is opened and the grid structure is first placed in the filling zone; then, the acoustic improving filler 15 or the expandable thermoplastic elastomer filler 14 is filled in the gap 13 formed by the lattice structure; next, the case 11 is closed; finally, the expandable thermoplastic elastomer filler 14 is foamed by means of heat radiation or the like.

The above filling method can achieve the foaming of the expandable thermoplastic elastomer filler 14 after the triggering, and further squeeze the acoustic improvement filler 15, and form the buffering effect.

In one example, the volume of the expandable thermoplastic elastomer filler increases 2 to 140 times after foaming. Thus, the foam padding has a good cushioning effect on the acoustic improvement padding 15.

Preferably, the volume of the expandable thermoplastic elastomer filler increases 3 to 110 times after foaming. Within the range, the foam filler has moderate buffering force and better buffering effect.

According to another embodiment of the present disclosure, there is provided a filling method of an acoustic conditioning material. The acoustic conditioning material is disposed within the filling area of the rear acoustic cavity of the sound generating device in any of the following ways:

in one example, the acoustic conditioning material is disposed within the filling zone in any of the following ways:

for example, as shown in fig. 1-2, the acoustic conditioning material is in the form of particles. The filling zone is filled with the expandable thermoplastic elastomer filling 14 first, and then with the acoustic improvement filling 15. In this example, a filling opening is provided in the housing 11. During filling, the granules are filled from the filling opening into the filling area. It is possible to use particles of different physical sizes for the acoustic improvement filler 15. The expandable thermoplastic elastomer filling 14 also employs particles of different physical sizes to provide a high fill rate of the acoustic tuning material in the filling zone.

It is also possible to use particles of the same physical size for both the acoustic improving filler 15 and the expandable thermoplastic elastomer filler 14 to ensure the consistency of the acoustic conditioning material.

For example, the acoustic conditioning material is in particulate form. The acoustic improvement filler 15 is first filled into the filling zone, and then the expandable thermoplastic elastomer filler 14 is filled into the filling zone. Likewise, during filling, the granules are filled from the filling opening into the filling region. It is possible to use particles of different physical sizes for the acoustic improvement filler 15. The expandable thermoplastic elastomer filling 14 also employs particles of different physical sizes to provide a high fill rate of the acoustic tuning material in the filling zone.

For example, the acoustic conditioning material is in particulate form. The expandable thermoplastic elastomer filler 14 and the sound-improving filler 15 are mixed first, and then the expandable thermoplastic elastomer filler 14 and the sound-improving filler 15 after mixing are filled into the filling zone.

Likewise, during filling, the granules are filled from the filling opening into the filling region. It is possible to use particles of different physical sizes for the acoustic improvement filler 15. The expandable thermoplastic elastomer filling 14 also employs particles of different physical sizes to provide a high fill rate of the acoustic tuning material in the filling zone.

For example, as shown in fig. 3-4, expandable thermoplastic elastomer filler 14 is first disposed in at least one wall portion of the filling zone to form an expandable thermoplastic elastomer filler layer; then, the acoustic improvement filler 15 is filled into the filling zone.

In this example, the acoustic conditioning material may be in the form of particles or sheets. The expandable thermoplastic elastomer filling 14 is bonded to at least one wall portion of the filling zone with an adhesive. The filling zone is then filled with the acoustically improving filler 15. In the triggered condition, the expandable thermoplastic elastomer filler 14 of the wall portion is foamed, thereby pressing the acoustic improvement filler 15 to dampen the movement of the acoustic improvement filler 15. The foamed expandable thermoplastic elastomer filler 14 serves as a buffer for the acoustic improving filler 15.

Optionally, a layer of expandable thermoplastic elastomer filler is formed in two opposing walls of the cavity. In the triggered condition, the expandable thermoplastic elastomer padding 14 of the two walls is foamed, so that the acoustic improvement padding 15 is squeezed in two opposite directions, which makes the foam padding have a better cushioning effect on the acoustic improvement padding 15.

In addition, the foamed expandable thermoplastic elastomer filler layer provides a cushioning effect on opposite sides of the acoustic improving filler 15, which makes the acoustic adjusting material more durable.

Further, an expandable thermoplastic elastomer filler layer is formed on all the wall portions of the cavity. In this way, the expandable thermoplastic elastomer filler layer provides a cushioning effect in any direction of the acoustic improving filler 15, which makes the durability of the acoustic adjusting material more excellent.

According to yet another embodiment of the present disclosure, an electronic device is provided. The electronic device may be, but is not limited to, a cell phone, a tablet, a smart watch, a game console, a learning machine, and the like.

The electronic equipment comprises the sound generating device of the embodiment of the disclosure. The electronic equipment has the characteristic of good acoustic effect.

< example 1>

The acoustic conditioning material includes an acoustic improving filler 15 and an expandable TPEE filler. The material of the acoustic improvement filler 15 is zeolite. The zeolite is in the form of granules with a physical size of 0.3mm-0.5mm and a density of 0.5 g/mL. The mass fraction of the expandable poly TPEE filler is 4 percent.

The sound generating device is a micro speaker module. The volume of the rear acoustic chamber 16 of the micro-speaker module is 0.4 cc. The acoustic conditioning material is mixed and filled into the rear acoustic chamber 16.

After filling, the micro-speaker module was placed in an oven and heated at 110 ℃ for 20 minutes to foam the expandable TPEE filler.

The foamed foam buffering filler has a physical size of 1.4mm and a density of 0.09g/mL, and the volume of the foam buffering filler accounts for 27% of the volume of the acoustic material filling mixture.

< comparative example 1>

In this example, the acoustic conditioning material and speaker module are consistent with the embodiments. Wherein the expandable TPEE filler is not triggered.

< comparative example 2>

The material of the acoustic adjusting material is zeolite. The zeolite is in the form of granules with a physical size of 0.3mm-0.5mm and a density of 0.5 g/mL.

The sound generating device is a micro speaker module. The module is the same as the module used in the embodiment. Acoustic conditioning material is potted into the rear acoustic chamber 16.

< test items >

1. F0 test: and respectively testing the frequency response curves of the three micro loudspeaker modules, and acquiring F0 of the three micro loudspeaker modules.

2. And (3) reliability testing: at the same power, three micro-speaker modules operated for 100 hours. Then, the F0 for the three micro-speaker modules was tested again.

After the test was completed, the acoustic conditioning material of the three micro-speaker modules was removed and the particle integrity of the acoustically improved filler 15 was observed.

< test results >

Table 1-comparative table of F0 for three micro speaker modules

	Comparative example 2	Comparative example 1	Example 1
				Micro speaker module F0	781 Hz	784 Hz	786 Hz

As can be seen from table 1, the F0 differences between the three micro-speakers are small. This indicates that, in example 1, although the foam cushion filler occupies a part of the volume of the rear chamber, the adsorption and desorption effects of the acoustic control material on the vibrating gas are not deteriorated.

TABLE 2-reliability comparison table for two micro speaker modules

	F0 before reliability test	F0 after reliability test	△ F0 variation	Acoustically modifying material particle state
					Comparative example 2	781 Hz	918 Hz	137 Hz	Severe particle breakage
Example 1	786 Hz	792 Hz	6 Hz	Without change

As can be seen from table 2, the F0 of the micro-speaker module of this example 1 was little changed and the particle state was not changed after the reliability test was performed. Whereas the F0 of the micro-speaker module of comparative example 2 showed a significant increase and the particles were severely broken.

This shows that the reliability of the acoustic adjustment material used in this embodiment is significantly better than that of the acoustic adjustment material used in comparative example 2, since the particles of the acoustic adjustment material are unchanged.

< example 2>

The acoustic conditioning material includes an acoustic improving filler 15 and an expandable TPEE filler. The material of the acoustic improvement filler 15 is zeolite. The zeolite is in the form of granules with a physical size of 0.3mm-0.5mm and a density of 0.5 g/mL. The mass fraction of expandable TPEE filler is 10 percent.

The foamed foam buffering filler has a physical size of 0.36mm and a density of 0.1g/mL, and the volume of the foam buffering filler accounts for 25% of the volume of the acoustic material filling mixture.

< comparative example 3>

< comparative example 4>

< test items >

< test results >

Table 3-comparative table of F0 for three micro speaker modules

Acoustic conditioning material	Comparative example 4	Comparative example 3	Example 2
				Micro speaker module F0	781 Hz	783 Hz	785 Hz

As can be seen from table 3, the F0 differences for the three micro-speakers are small. This indicates that, in example 2, the volume of the cavity portion was occupied after foaming, but the adsorption and desorption effects of the acoustic control material on the vibration gas were not deteriorated.

TABLE 4-reliability comparison table for two micro speaker modules

	F0 before reliability test	F0 after reliability test	△ F0 variation	Acoustically modifying material particle state
					Comparative example 4	781 Hz	918 Hz	137 Hz	Severe particle breakage
Example 2	785 Hz	791 Hz	6 Hz	Without change

As can be seen from table 4, after the reliability test was performed, F0 of the micro-speaker module of example 2 was changed by 6 Hz, whereas F0 of the micro-speaker module of comparative example 4 was changed by 137 Hz.

This shows that the reliability of the acoustic adjustment material used in this embodiment is significantly better than that of the acoustic adjustment material used in comparative example 4, since the particles of the acoustic adjustment material are unchanged.

< example 3>

The acoustic conditioning material includes an acoustic improving filler 15 and an expandable TPEE filler. Wherein, the material of the acoustic improvement filler 15 is molecular sieve. The molecular sieve is granular, the physical size is 0.3mm-0.5mm, and the density is 0.5 g/mL. The mass fraction of expandable TPEE filler is 1.7 percent.

The physical size of the foam cushion filler after foaming was 20mm, the density was 0.07g/mL, and the volume of the foam cushion filler was 55% of the volume of the acoustic material-filled mixture.

< comparative example 5>

< comparative example 6>

The material of the acoustic adjusting material is a molecular sieve. The molecular sieve is granular, the physical size is 0.3mm-0.5mm, and the density is 0.5 g/mL.

< test items >

< test results >

TABLE 5-comparative table of F0 for three micro speaker modules

Acoustic conditioning material	Comparative example 6	Comparative example 5	Example 3
				Micro speaker module F0	781 Hz	785 Hz	786 Hz

As can be seen from table 5, F0 for the speaker of example 3 was substantially the same as that of comparative examples 5 and 6. This indicates that, in example 3, although the foam cushion filler occupies a part of the volume of the rear chamber, the adsorption and desorption effects of the acoustic conditioning material on the vibrating gas are not deteriorated.

TABLE 6-reliability comparison table for two micro speaker modules

	ReliabilityF0 before sexual test	F0 after reliability test	△ F0 variation	Acoustically modifying material particle state
					Comparative example 6	781 Hz	918 Hz	137 Hz	Severe particle breakage
Example 3	786 Hz	791 Hz	5 Hz	Without change

As can be seen from table 6, the F0 of the micro-speaker module of this example 3 was little changed and there was no change in the particle state after the reliability test was performed. Whereas the F0 of the micro-speaker module of comparative example 6 showed a significant increase and the particles were severely broken.

This shows that the reliability of the acoustic adjustment material used in this embodiment is significantly better than that of the acoustic adjustment material used in comparative example 6, since the particles of the acoustic adjustment material are unchanged.

In the above embodiments, the differences between the embodiments are described in emphasis, and different optimization features between the embodiments can be combined to form a better embodiment as long as the differences are not contradictory, and further description is omitted here in consideration of brevity of the text.

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

Claims

1. An acoustic conditioning material, comprising: the acoustic improvement filler comprises an expandable thermoplastic elastomer filler and an acoustic improvement filler, wherein the expandable thermoplastic elastomer filler is foamed under a triggered condition to form a foam filler so as to provide a buffer effect for the acoustic improvement filler during moving collision, the foamed volume of the expandable thermoplastic elastomer filler is changed along with the change of temperature and/or foaming time, the damping of the expandable thermoplastic elastomer filler is increased when the temperature is increased, and the buffer capacity is enhanced.

2. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler is of the type of one or more of a polyolefin thermoplastic elastomer, a thermoplastic vulcanizate, a thermoplastic polyurethane elastomer, a thermoplastic polyester elastomer, and a styrenic block copolymer.

3. The acoustic conditioning material of claim 1, wherein the acoustic improving filler is a material with acoustic properties made of one or more of activated carbon, zeolite powder, silica, porous alumina, molecular sieve, metal-organic framework material.

4. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler is in the form of particles, flakes, or blocks.

5. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler has a density of 0.005g/mL to 0.8g/mL after foaming.

6. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler is in particulate form and, after expansion, has a physical size of 0.1mm to 23 mm.

7. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler comprises a thermoplastic elastomer material and a blowing agent mixed together, wherein the blowing agent comprises a low boiling alkane.

8. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler is triggered by at least one of thermal radiation, optical radiation, electromagnetic radiation.

9. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler comprises 0.01% -40% of the total volume of the acoustic conditioning material prior to foaming; after foaming, the volume of the foam filler accounts for 0.05-65% of the total volume of the acoustic conditioning material.

10. The acoustic conditioning material of claim 1, wherein the expandable thermoplastic elastomer filler comprises 0.1% -20% of the total volume of the acoustic conditioning material prior to foaming; after foaming, the volume of the foam filler is 5% -60% of the total volume of the acoustic conditioning material.

11. Acoustic conditioning material according to any of claims 1-10, characterized in that the expandable thermoplastic elastomer filler is triggered by a physical or chemical foaming process.

12. The acoustic conditioning material of claim 1, wherein the foaming process of the expandable thermoplastic elastomer filler includes a first foaming stage resulting in a first foam cushion filler and a second foaming stage resulting in a second foam cushion filler.

13. The acoustic conditioning material of claim 12, wherein the volume of the second foam cushion filler is 1-25 times the volume of the first foam cushion filler.

14. A sound generating device, comprising a housing, a sound generating unit and the acoustic adjusting material according to any one of claims 1 to 13, wherein the interior of the housing forms a cavity, the cavity comprises a rear sound cavity, the sound generating unit is disposed in the cavity, the sound generating unit is communicated with the rear sound cavity, the rear sound cavity comprises a filling area, and the acoustic adjusting material is disposed in the filling area.

15. The sound generating apparatus of claim 14, wherein the acoustic conditioning material has a fill rate of 50% -95% in the filling zone prior to foaming.

16. The sound-emitting device according to claim 14, wherein both the expandable thermoplastic elastomer filler and the acoustic enhancement filler are particulate materials,

17. The sound emitting device of claim 14, wherein the expandable thermoplastic elastomer filler and the acoustic enhancement filler are both bulk materials,

18. The sound-emitting device according to claim 14, wherein the expandable thermoplastic elastomer filler forms a lattice structure, and the acoustic improvement filler is filled in gaps formed by the expandable thermoplastic elastomer filler; or

The acoustic improvement filler forms a lattice structure, and the expandable thermoplastic elastomer filler is filled in gaps formed by the acoustic improvement filler.

19. A method of filling an acoustic conditioning material for a sound generating device, wherein the acoustic conditioning material of any of claims 1-13 is disposed in a filling area of a rear acoustic cavity of the sound generating device in any of the following ways:

20. An electronic device, characterized in that it comprises a sound emitting device according to any one of claims 14-18.