阅读说明：本技术 一种振动板以及发声装置 (Vibration board and sound generating mechanism ) 是由 李美玲 凌风光 李春 于 2019-08-02 设计创作，主要内容包括：本发明公开了一种振动板,包括至少一层碳纤维层,所述碳纤维层采用长纤维和树脂浸润混合制成,所述树脂中添加有碳纤维粉,所述树脂中的碳纤维粉的质量含量为5％-25％,所述碳纤维层中的长纤维的质量含量为40％-75％。本发明在树脂中添加碳纤维粉改善了长纤维在预浸过程中而造成的开缝缺陷,提高碳纤维层的整体强度和耐磨性。(The invention discloses a vibrating plate which comprises at least one carbon fiber layer, wherein the carbon fiber layer is prepared by soaking and mixing long fibers and resin, carbon fiber powder is added into the resin, the mass content of the carbon fiber powder in the resin is 5% -25%, and the mass content of the long fibers in the carbon fiber layer is 40% -75%. According to the invention, the carbon fiber powder is added into the resin, so that the slotting defect caused by long fibers in the pre-dipping process is overcome, and the overall strength and the wear resistance of the carbon fiber layer are improved.)

1. The vibrating plate is characterized by comprising at least one carbon fiber layer, wherein the carbon fiber layer is prepared by soaking and mixing long fibers and resin, carbon fiber powder is added into the resin, the mass content of the carbon fiber powder in the resin is 5% -25%, and the mass content of the long fibers in the carbon fiber layer is 40% -75%.

2. The vibrating plate according to claim 1, wherein the carbon fiber powder is long cylindrical fine particles obtained by subjecting the long fibers to surface treatment, process grinding, micro-screening, and high-temperature drying.

3. A vibration plate according to claim 2, wherein the carbon fiber powder has a diameter in the range of 4 to 7 μm, a length in the range of 0.01 to 12mm, and a specific surface area of more than 0.321663m²/g。

4. The vibrating plate according to claim 1, wherein the long fiber has a strength in the range of T300 to T1000, and a modulus in the range of M30 to M60.

5. The vibrating plate according to claim 1, wherein a surface treatment agent and a dispersant are added to the carbon fiber powder;

And/or carrying out ultrasonic treatment on the carbon fiber powder.

6. A vibrating plate according to claim 5, wherein the surface treatment agent is at least one of a silane coupling agent and a plasma treatment agent, and the dispersant is at least one of Methyl Cellulose (MC), sodium carboxymethyl cellulose (CMC), and hydroxyethyl cellulose (HEC).

7. The vibrating plate of claim 1, wherein the vibrating plate is a single-layer vibrating plate comprising a carbon fiber layer, and the thickness of the single-layer vibrating plate is in a range of 0.05mm to 0.3 mm.

8. A vibrating plate according to claim 1, characterized in that the vibrating plate is a composite vibrating plate comprising a plurality of carbon fiber layers, the composite vibrating plate having a thickness in the range of 0.1-0.5 mm.

9. A vibrating plate according to claim 8, further comprising an intermediate layer disposed between the carbon fiber layers, the intermediate layer having a thickness in a range of 0.05-0.4 mm.

10. the vibrating plate according to claim 9, wherein the intermediate layer is made of a foam material or an engineering plastic, and the foam material is at least one of a PMI foam material, a PI foam material and a polyester foam material.

11. The vibration plate according to claim 1 or 10, wherein the vibration plate is formed in one step by a hot press process, and the vibration plate has a flat plate structure, or has a convex structure or a concave structure.

12. A sound-generating device, comprising a vibration system and a magnetic circuit system cooperating with the vibration system, wherein the vibration system comprises a diaphragm and a vibrating plate according to any one of claims 1 to 11, and the diaphragm and the vibrating plate are connected by bonding.

Technical Field

The present invention relates to the field of electroacoustic conversion, and more particularly, to a vibrating plate and a sound generating device.

Background

Carbon fibers have the advantage of high specific modulus, so that the carbon fibers are widely applied to the fields of aerospace and the like, and in recent years, the carbon fibers are gradually applied to the field of acoustics to improve the rigidity of a loudspeaker and the high-frequency performance of the loudspeaker.

since products in the acoustic field are limited in mass, light in mass and small in structure are required, and thus, carbon fiber materials used as speakers are prepregs of unidirectional fibers. The material has obvious orientation, and edge cracks are easy to generate in a certain direction due to the strength reduction in the direction during processing and use, and noise and the like are usually generated when the material is manufactured into a loudspeaker.

Disclosure of Invention

An object of the present invention is to provide a vibration plate and a sound emitting device.

According to the first aspect of the invention, the vibrating plate comprises at least one carbon fiber layer, wherein the carbon fiber layer is prepared by infiltrating and mixing long fibers and resin, carbon fiber powder is added into the resin, the mass content of the carbon fiber powder in the resin is 5% -25%, and the mass content of long fibers in the carbon fiber layer is 40% -75%.

Optionally, the carbon fiber powder is long cylindrical particles prepared by performing surface treatment, process grinding, micro-screening and high-temperature drying on the long fibers.

Optionally, the carbon fiber powder has a diameter ranging from 4 to 7 μm, a length ranging from 0.01 to 12mm, and a specific surface area greater than 0.321663m²/g。

Optionally, the long fiber has a strength in the range of T300-T1000 and a modulus in the range of M30-M60.

Optionally, a surface treatment agent and a dispersing agent are added into the carbon fiber powder;

And/or carrying out ultrasonic treatment on the carbon fiber powder.

Optionally, the surface treatment agent adopts at least one of silane coupling agent and plasma treatment agent, and the dispersing agent adopts at least one of Methyl Cellulose (MC), sodium carboxymethyl cellulose (CMC) and hydroxyethyl cellulose (HEC).

Optionally, the vibrating plate is a single-layer vibrating plate, the single-layer vibrating plate includes a carbon fiber layer, and a thickness of the single-layer vibrating plate ranges from 0.05mm to 0.3 mm.

Optionally, the vibrating plate is a composite vibrating plate, the composite vibrating plate includes a plurality of carbon fiber layers, and the thickness of the composite vibrating plate ranges from 0.1 mm to 0.5 mm.

Optionally, the vibrating plate further comprises an intermediate layer, the intermediate layer is arranged between the carbon fiber layers, and the thickness of the intermediate layer ranges from 0.05mm to 0.4 mm.

Optionally, the intermediate layer is made of a foam material or engineering plastics, and the foam material is at least one of PMI foam material, PI foam material and polyester foam material.

Optionally, the vibration plate is formed in one step by using a hot pressing process, and the vibration plate is of a flat plate structure, or the vibration plate has a convex structure or a concave structure.

According to another aspect of the present invention, a sound generating device is provided, which includes a vibration system and a magnetic circuit system cooperating with the vibration system, where the vibration system includes a vibrating diaphragm and the vibrating diaphragm, and the vibrating diaphragm are connected by bonding.

The inventor of the present invention finds that in order to improve the structure of the unidirectional carbon fiber vibration plate, the prior art adopts a mode of adding a symmetrical layer on the vibration plate. However, adding a symmetrical ply increases the overall mass of the diaphragm, which in turn results in a decrease in the modulus to density ratio. Those skilled in the art have not recognized that when such a diaphragm is applied to a speaker, the sensitivity and high frequency FR of the speaker are reduced, resulting in a reduction in acoustic performance. Therefore, the technical task to be achieved or the technical problems to be solved by the present invention are never thought or anticipated by those skilled in the art, and therefore the present invention is a new technical solution.

The invention has the beneficial effects that: compared with the prior art, the carbon fiber layer is prepared by soaking and mixing long fibers and resin, and the carbon fiber powder is added into the resin, so that the strength of the vibrating plate in all directions or the local strength of the vibrating plate is reinforced, and the strength of the vibrating plate is improved.

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 graph showing the relationship between the mass content of the carbon fiber powder of the present invention and the tensile strength of the resin.

Fig. 2 shows THD curves of a carbon fiber vibration plate in the prior art and an improved carbon fiber vibration plate according to the present invention.

Fig. 3 is a RB graph showing a carbon fiber vibration plate of the related art and an improved carbon fiber vibration plate of the present invention.

Fig. 4 shows an amplitude cloud of the diaphragm at a high frequency of 10k before and after the improvement.

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 invention, the vibrating plate comprises at least one carbon fiber layer, the carbon fiber layer is made by infiltrating and mixing long fibers and resin, carbon fiber powder is added into the resin, the mass content of the carbon fiber powder in the resin is 5% -25%, and the mass content of long fibers in the carbon fiber layer is 40% -75%.

Optionally, the vibrating plate is a single-layer vibrating plate, specifically, the single-layer vibrating plate includes a carbon fiber layer, and a thickness of the single-layer vibrating plate is in a range of 0.05mm to 0.3 mm. The inventor finds that the thickness of the vibrating plate is within the range, the vibrating plate is light in weight, the vibration frequency of each position of the vibrating plate is consistent under the action of the driving force, the vibrating plate has the strength capable of fully bearing the sound pressure when being applied to a sound generating device, the vibrating consistency of the vibrating plate and the vibrating plate is good in the vibrating process of the vibrating plate, and the acoustic performance of the sound generating device is excellent.

Optionally, the vibrating plate is a composite vibrating plate, the composite vibrating plate includes a plurality of carbon fiber layers, and the thickness of the composite vibrating plate ranges from 0.1 mm to 0.5 mm. The inventor finds that the thickness of the vibrating plate is in the range, the vibrating plate is light in weight, the vibration frequency of each position of the vibrating plate is consistent under the action of the driving force, the amplitude of vibration of the vibrating plate can be larger, when the vibrating plate is made into a sound generating device, the vibrating plate is bonded with the vibrating plate to vibrate together, the vibration space allowance in the sound generating device is larger, and the listening effect of the sound generating device can be better.

Optionally, the vibrating plate further comprises an intermediate layer, the intermediate layer is arranged between the carbon fiber layers, and the thickness of the intermediate layer ranges from 0.05mm to 0.4 mm. The middle layer and the carbon fiber layer are connected in a bonding mode and the like.

Optionally, the intermediate layer is made of a foam material or engineering plastics, and the foam material is at least one of PMI foam material, PI foam material and polyester foam material.

According to one embodiment of the invention, the carbon fiber layer is made by infiltrating and mixing the long fibers with a resin to which carbon fiber powder is added.

Optionally, the long fibers are unidirectional carbon fibers, the long fibers have a strength in the range of T300-T1000, and the long fibers have a modulus in the range of M30-M60.

Specifically, the resin is epoxy resin, and carbon fiber powder is added into the epoxy resin. The epoxy resin has strong adhesion, outstanding dimensional stability and durability, and good chemical performance; the carbon fiber powder retains the excellent performance of carbon fiber, has fine shape, pure surface and large specific surface area, is easy to be wetted and uniformly dispersed by resin, and can be well compatible with the resin. Meanwhile, the carbon fiber powder has high strength and light weight, and the long fiber is soaked in the resin to form a carbon fiber layer; the carbon fiber layer is light in weight and strong in acid resistance and alkali resistance; when the carbon fiber layer is manufactured into the vibrating plate through hot press molding, the vibrating plate is light in weight and strong in chemical resistance; when the vibration plate is applied to the sound generating device, the vibration plate is light in weight, moderate in rigidity and good in acoustic performance, and has certain flexibility, so that a good supporting effect can be achieved, the vibration consistency of the vibration plate and the vibration plate is good, the high-frequency tone quality of the sound generating device is improved, and the acoustic performance of the sound generating device is good.

The mass content of the carbon fiber powder in the resin is 5-25%, namely the mass content of the carbon fiber powder accounts for 5-25% of the total mass of the resin. When the content of the carbon fiber powder in the resin is low, the resin has the defects of bubbles and the like due to the addition of a small amount of the carbon fiber powder, so that long fibers are soaked in the resin to form a carbon fiber layer with a rough surface, and when the carbon fiber layer is manufactured into a vibrating plate by hot press molding, the vibrating plate has the rough surface and uneven quality and density; when the vibrating plate is applied to the sound generating device, in the vibrating process of the vibrating diaphragm, the vibrating consistency of the vibrating diaphragm and the vibrating plate cannot be guaranteed due to the rough surface and uneven quality and density of the vibrating diaphragm, and the vibrating diaphragm is easy to polarize in the vibrating process, so that the acoustic performance of the sound generating device is lost; when the carbon fiber powder content is higher than 25%, the resin viscosity is high, so that the wettability of resin and long fibers is poor, the resin cannot be compatible with the long fibers better, the tensile strength of the resin is reduced, the tensile strength of a formed carbon fiber layer is reduced, the texture is uneven, the strength perpendicular to the direction of the long fibers is inconsistent, when the carbon fiber layer is manufactured into the vibrating plate through hot press forming, the texture of the vibrating plate is uneven, the wear resistance and the overall strength of the vibrating plate are uneven, when the vibrating plate is applied to a sound generating device, the vibrating diaphragm is in the vibrating process, the vibrating consistency of the vibrating diaphragm and the vibrating plate is poor due to the uneven texture of the vibrating plate, and the FR high frequency and the acoustic performance of the sound generating device are reduced.

The mass content of long fibers in the carbon fiber layer is 40-75%, when the content of the long fibers is low, the forming effect of the carbon fiber layer along the length direction of the long fibers is poor, the strength of the long fibers in the length direction is reduced, and the mass and the strength of the carbon fiber layer are reduced; when the content of the long fibers is high, the strength of the carbon fiber layer is not uniform, the carbon fiber layer is made into the vibrating plate, so that the wear resistance and the overall strength of the vibrating plate are not uniform, and when the vibrating plate is applied to the sound production device, the vibrating diaphragm is poor in vibration consistency of the vibrating diaphragm and the vibrating plate due to the fact that the texture of the vibrating plate is not uniform in the vibrating process.

Optionally, the carbon fiber powder is subjected to surface treatment and dispersing agent treatment, and/or carbon fiber powder is subjected to ultrasonic treatment.

The surface treating agent is at least one of silane coupling agent and plasma treating agent; the dispersant is at least one of Methylcellulose (MC), sodium carboxymethylcellulose (CMC) and hydroxyethyl cellulose (HEC).

The surface treating agent introduces polar groups to the surface of the carbon fiber powder, so that the carbon fiber powder can be better compatible with resin. The dispersing agent can well break the agglomeration of the carbon fiber powder and better disperse the carbon fiber powder in the resin. The ultrasonic treatment is to disperse the carbon fiber powder in a vibration mode so that the carbon fiber powder is better compatible with resin.

Optionally, a side feeding mode can be adopted, and specifically, a feeding machine is adopted to uniformly add the carbon fiber powder into the resin, so that the carbon fiber powder is better compatible with the resin.

Alternatively, the carbon fiber powder may be added during the curing of the resin to form a film or before the resin is not cured, so that the carbon fiber powder is compatible with the resin.

Fig. 1 is a graph showing the relationship between the mass content of carbon fiber powder and the tensile strength of resin, the tensile strength: the ability of a material to resist permanent deformation and failure under an external force.

As shown in fig. 1, the abscissa represents the carbon fiber content (%), and the ordinate represents the tensile strength (MPa). When the carbon fiber content is 0-5%, the tensile strength of the resin is gradually reduced; when the carbon fiber content is 5% -20%, the tensile strength of the resin is gradually improved along with the gradual increase of the carbon fiber powder content; when the carbon fiber content is 20-30%, the tensile strength of the resin is gradually reduced along with the gradual increase of the carbon fiber powder content.

When the carbon fiber content is 15% -25%, the tensile strength of the resin is improved relative to the strength of the resin, when the tensile strength of the resin is improved, the tensile strength of a carbon fiber layer formed by soaking long fibers and the resin is improved, when the carbon fiber layer is manufactured into a vibration plate through hot press molding, the tensile strength of the vibration plate is large, the permanent deformation and damage resistance is high, the vibration plate is applied to a sound production device, the vibration plate is connected with the vibration plate in an adhesive mode, the vibration consistency of the vibration plate and the vibration plate is good in the vibration process of the vibration plate, and the acoustic performance of the sound production device is good.

Optionally, the diaphragm is bonded to the vibrating plate, specifically, the diaphragm is bonded to the vibrating plate by glue or an adhesive tape, and the diaphragm is formed by compounding one or more materials of engineering plastics (such as peek, par, and the like), elastomer materials (such as tpu, tpee, silicon rubber, and the like), adhesive films (such as acrylate adhesives, silicone adhesives, and the like), and the like; the thickness of the vibrating diaphragm is between 0.01mm and 0.5mm, the sensitivity of the vibrating diaphragm of the sound production device is higher in the thickness range, the vibrating diaphragm generates larger amplitude and higher corresponding speed under the condition of applying the same driving force, and further, the margin of the vibration space of the vibrating diaphragm is larger.

Optionally, the carbon fiber powder is isometric cylindrical particles obtained by performing surface treatment, process grinding, micro-screening and high-temperature drying on long fibers, the diameter range of the carbon fiber powder is 4-7 μm, the length range of the carbon fiber powder is 0.01-12mm, and the specific surface area of the carbon fiber powder is larger than 0.321663m²(ii) in terms of/g. Specific surface area: the specific surface area of the carbon fiber powder in the invention is the total surface area of the carbon fiber powder in unit mass.

The specific surface area of the carbon fiber powder is larger than 0.321663m²And/g, the carbon fiber powder can be well compatible with the resin without influencing the infiltration of the resin and the long fiber. Meanwhile, the carbon fiber powder can well improve the hardness, crack resistance, wear resistance and dimensional stability of the resin; the carbon fiber powder also overcomes the defect of slotting caused by the expansion of long fibers, and improves the phenomenon of edge cracking of the long fibers.

In the carbon fiber layer formed by impregnating the long fibers with the resin in the present embodiment, the carbon fiber layer has improved overall strength and hardness, good rigidity, and improved wear resistance. When the carbon fiber layer is manufactured into the vibrating plate through hot press molding, the strength perpendicular to the long fiber direction is enhanced, the strength of the carbon fiber layer in each direction is enhanced, the wear resistance of the vibrating plate is improved, and the rigidity is improved; the uniformity of the strength is improved, and the vibrating plate is applied to the sound generating device, so that the high frequency FR of the sound generating device is improved, the THD (total harmonic distortion) and RB (noise ratio) are reduced, and the polarization in the high-frequency vibration process is obviously reduced.

Fig. 2 is a graph showing THD (total harmonic distortion) curves of a carbon fiber vibration plate and a vibration plate of the present invention in the prior art. As shown in fig. 2, the abscissa is frequency (Hz), the ordinate is total harmonic distortion (%), and the solid line is the THD graph of the carbon fiber vibration plate in the related art; the broken line is the THD curve of the vibrating plate of the present invention. As can be seen from fig. 2, in the high frequency region, the THD curve of the vibrating plate of the present invention is relatively lower, and the peak and valley phenomena existing in the carbon fiber vibrating plate in the prior art do not occur.

Fig. 4 shows an amplitude cloud at a high frequency of 10k for a prior art diaphragm and a diaphragm of the present invention. As shown in fig. 4, the first graph is an amplitude cloud graph of a carbon fiber vibrating plate in the prior art at a high frequency of 10k, and the second graph is an amplitude cloud graph of a vibrating plate of the present invention at a high frequency of 10k, and as can be seen from fig. 4, when the vibrating plate of the present invention vibrates in a high frequency of 10k, the vibration amplitude of the vibrating plate still exists and the vibration consistency is still good, and the upper and lower vibration amplitudes shown in the first graph are not consistent, and the vibration amplitudes are obviously in a disordered state.

FIG. 3 is a RB (noise ratio) graph of a prior art carbon fiber vibrating plate and a vibrating plate of the present invention, as shown in FIG. 2, with the abscissa being frequency (Hz), the ordinate being RB (%), and the solid line being the RB graph of the prior art carbon fiber vibrating plate; the dotted line is the RB graph of the vibrating plate of the present invention. In a high-frequency area, the RB curve of the vibrating plate is relatively lower, which shows that the vibrating plate generates less noise in the vibrating process and effectively improves the listening yield.

Optionally, the vibration plate is formed in one step by using a hot pressing process, and the vibration plate is of a flat plate structure, or the vibration plate has a convex structure or a concave structure.

Alternatively, the long fiber direction of the carbon fiber layer is perpendicular to the long axis of the diaphragm during the cutting process, so that the overall strength of the diaphragm can be improved.

Optionally, the vibrating plate is adapted for SPK, RCV configuration.

According to another embodiment of the present invention, a sound generating device is provided, which includes a vibration system and a magnetic circuit system cooperating with the vibration system, wherein the vibration system includes a diaphragm and the above-mentioned diaphragm, and the diaphragm are connected by bonding. The sound generating device has good high-frequency sound quality, THD and RB are reduced, and the acoustic performance of the sound generating device is improved.

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.