阅读说明：本技术 用于发声装置的振动板及发声装置 (Vibrating plate for sound production device and sound production device ) 是由 惠冰 凌风光 李春 于 2020-11-02 设计创作，主要内容包括：本申请实施例提供了一种用于发声装置的振动板及发声装置,所述振动板至少部分采用复合材料制成,所述复合材料包括聚合物基体和分散在所述聚合物基体中的补强材料,所述补强材料包括碳纤维,所述补强材料在所述复合材料中的质量分数范围为10％-70％。本申请实施例提供的振动板至少部分采用复合材料制成,所述复合材料通过将所述碳纤维补强材料分散在所述聚合物基体中,增强了所述振动板的模量和结构强度,使得安装所述振动板的发声装置具有较宽的频响范围和较低的失真,提高了发声装置的发声效果。(The embodiment of the application provides a vibration board and sound generating mechanism for sound generating mechanism, the vibration board is at least partly to adopt combined material to make, combined material includes the polymer base and disperses the reinforcement material in the polymer base, the reinforcement material includes the carbon fiber, the reinforcement material is in the mass fraction scope in the combined material is 10% -70%. The vibration board that this application embodiment provided at least part adopts combined material to make, combined material is through inciting somebody to action carbon fiber reinforcement material disperses in the polymer base, strengthened the modulus and the structural strength of vibration board make the installation the sound generating mechanism of vibration board has the frequency response scope of broad and lower distortion, has improved sound generating mechanism's vocal effect.)

1. The vibrating plate for the sound production device is characterized in that at least part of the vibrating plate is made of a composite material, the composite material comprises a polymer matrix and a reinforcing material dispersed in the polymer matrix, the reinforcing material comprises carbon fibers, and the mass fraction range of the reinforcing material in the composite material is 10% -70%.

2. A vibrating plate according to claim 1, wherein the polymer matrix comprises at least one of polypropylene (PP), Polycarbonate (PC), Polyamide (PA), Polyoxymethylene (POM), polyphenylene oxide (PPO).

3. A vibration plate according to claim 1, wherein an orientation angle of the carbon fiber is less than or equal to 30 °.

4. A vibrating plate according to claim 1, wherein the carbon fiber form factor is in the range of 0.1-1.5.

5. The vibrating plate according to claim 1, wherein the carbon fiber is a chopped carbon fiber, and a length of the chopped carbon fiber is in a range of 0.1mm to 20 mm.

6. A vibrating plate according to claim 1, characterized in that the modulus of the vibrating plate is greater than or equal to 2.5 GPa.

7. A vibration plate according to claim 1, wherein a molding manner of the vibration plate is injection molding.

8. The vibrating plate according to claim 1, wherein the vibrating plate is a single-layer vibrating plate made of the composite material;

or the vibration plate is a composite vibration plate, the composite vibration plate comprises at least two layers, and at least one layer of the composite vibration plate comprises the composite material.

9. A vibration plate according to claim 8, wherein the single layer vibration plate has a thickness in a range of 50 μm to 2800 μm.

10. A sound-generating device comprising a vibration system and a magnetic circuit system cooperating with said vibration system, said vibration system comprising a vibration plate according to any one of claims 1 to 9.

Technical Field

The application belongs to the technical field of electronic products, specifically, this application relates to a vibration board and sound generating mechanism for sound generating mechanism.

Background

A speaker is an important acoustic component in a portable electronic device, and is used to convert a sound wave electric signal into a sound signal and generate an external sound. In order to reduce the distortion of the speaker and to improve the sensitivity of the speaker, a vibration plate is usually fixed to the center of the vibration film to enhance the rigidity of the center of the vibration film.

The conventional vibrating plate is generally formed by punching wood chips, plastic or aluminum, which results in low strength of the vibrating plate. In the vibrating process of the vibrating diaphragm, the vibrating plate may be deformed, which affects the sound quality and the service life of the speaker.

Disclosure of Invention

An object of the embodiment of the application is to provide a vibrating plate for a sound generating device and a technical scheme of the sound generating device.

According to a first aspect of embodiments of the present application, there is provided a vibration plate for a sound generating apparatus, the vibration plate being at least partially made of a composite material, the composite material including a polymer matrix and a reinforcing material dispersed in the polymer matrix, the reinforcing material including carbon fibers, and a mass fraction of the reinforcing material in the composite material being in a range of 10% to 70%.

Optionally, the polymer matrix comprises at least one of polypropylene (PP), Polycarbonate (PC), Polyamide (PA), Polyoxymethylene (POM), polyphenylene oxide (PPO).

Optionally, the orientation angle of the carbon fibers is less than or equal to 30 °.

Optionally, the carbon fiber form factor ranges from 0.1 to 1.5.

Optionally, the carbon fibers are chopped carbon fibers, and the length of the chopped carbon fibers ranges from 0.1mm to 20 mm.

Optionally, the modulus of the vibration plate is greater than or equal to 2.5 GPa.

Optionally, the vibration plate is formed by injection molding.

Optionally, the vibrating plate is a single-layer vibrating plate, and the single-layer vibrating plate is made of the composite material;

or the vibration plate is a composite vibration plate, the composite vibration plate comprises at least two layers, and at least one layer of the composite vibration plate comprises the composite material.

Optionally, the thickness of the single-layer vibrating plate is in a range of 50 μm to 2800 μm.

According to a second aspect of embodiments of the present application, there is provided a sound generating apparatus, comprising a vibration system and a magnetic circuit system cooperating with the vibration system, wherein the vibration system comprises the vibration plate of the first aspect.

One technical effect of the embodiment of the application is as follows:

the embodiment of the application provides a vibration board for a sound generating device, at least part of the vibration board is made of composite materials, the composite materials comprise a polymer matrix and reinforcing materials dispersed in the polymer matrix, the reinforcing materials comprise carbon fibers, and the mass fraction range of the reinforcing materials in the composite materials is 10% -70%. The vibration board that this application embodiment provided at least partly adopts combined material to make, combined material is through inciting somebody to action carbon fiber reinforcement material disperses in the polymer base body, strengthened the modulus and the structural strength of vibration board make the vibration board material have the frequency response scope of broad and lower distortion simultaneously to can improve sound generating mechanism's vocal effect.

Further features of the present application and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

Drawings

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

FIG. 1 is a graph of mass fraction of carbon fiber reinforcement material in the composite material versus modulus of the vibration plate made from the composite material provided in the examples of the present application;

fig. 2 is a graph comparing Fr test curves of the vibration plate provided in the example of the present application and the conventional vibration plate.

Detailed Description

Various exemplary embodiments of the present application 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 application 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 application, 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.

The embodiment of the application provides a vibration board for sound generating mechanism, and this sound generating mechanism can be the speaker, the vibration board is at least partly to adopt combined material to make, combined material includes the polymer base and disperses the reinforcement material in the polymer base, the reinforcement material includes the carbon fiber, the reinforcement material is in the mass fraction scope in the combined material is 10% -70%. Optionally, the mass fraction of the reinforcing material in the composite material may range from 20% to 50%. The reinforcing material may be uniformly dispersed in the polymer matrix to improve the performance stability of the composite.

Specifically, Carbon Fiber (CF) is a novel fiber material of high-strength and high-modulus fiber with a carbon content of more than 95%. The carbon fiber is a microcrystalline graphite material obtained by stacking organic fibers such as flaky graphite microcrystals along the axial direction of the fiber and performing carbonization and graphitization treatment. The carbon fiber has the characteristics of outer flexibility and inner rigidity, is lighter in density than metal aluminum, but higher in strength than steel and iron, and has the characteristics of corrosion resistance and high modulus. The modulus may be an elastic modulus, specifically including a flexural modulus, a compressive modulus, and a shear modulus. Fig. 1 shows a graph of mass fraction of carbon fiber reinforcement in the composite material versus modulus of the vibrating plate made from the composite material, and it can be seen that as the mass fraction of carbon fiber in the composite material increases, the flexural modulus of the vibrating plate made from the composite material increases significantly. In particular to the process that the mass fraction of the carbon fiber reinforced material in the composite material is increased from 10% to 50%, the flexural modulus of the vibrating plate is increased from 3.6GPa to 12.3 GPa; in the process that the mass fraction of the carbon fiber reinforced material in the composite material is increased from 50% to 70%, the flexural modulus of the vibrating plate is improved, but the reinforcing effect of the carbon fiber reinforced material is fully exerted, and the flexural modulus of the vibrating plate is not obviously improved. When the mass fraction of the carbon fiber reinforcing material in the composite material exceeds 70%, too much carbon fiber may lower the melt index of the polymer matrix, resulting in poor flowability of the polymer matrix and reduced uniformity of dispersion of the reinforcing material in the composite material.

The vibration board that this application embodiment provided at least part adopts combined material to make, combined material is through inciting somebody to action carbon fiber reinforcement material disperses in the polymer base, strengthened the modulus and the structural strength of vibration board make the installation the sound generating mechanism of vibration board has the frequency response scope of broad and lower distortion, has improved sound generating mechanism's vocal effect. In addition, the carbon fiber reinforcing material can also improve the heat resistance, the dimensional stability and the damping performance of the vibration plate.

Optionally, the polymer matrix comprises at least one high molecular Polymer of Polypropylene (PP), Polycarbonate (PC), Polyamide (PA), Polyoxymethylene (POM), polyphenylene oxide (PPO). The carbon fiber reinforced polypropylene material has higher elastic modulus, heat resistance and dimensional stability, and simultaneously has proper damping performance, so that the vibrating plate has wider frequency response range and lower distortion, and the sound production effect of sound production devices such as a loudspeaker is improved.

Specifically, the polymer material such as polypropylene has chemical resistance, heat resistance, high-strength mechanical properties and good high-wear-resistance processability, and when the carbon fiber reinforcement material is dispersed in the polymer matrix, the carbon fiber reinforcement material needs to be uniformly dispersed in the polymer matrix in a molten state after the polymer matrix is melted, so that the carbon fiber reinforcement material can be more uniformly and sufficiently dispersed due to the good flowing property of the polymer material such as polypropylene, and the uniformity and the performance stability of the composite material are improved.

Optionally, the orientation angle of the carbon fibers is less than or equal to 30 °.

Specifically, the orientation angle is an included angle between graphite microcrystals in the carbon fibers and a fiber axis, and when the orientation angle is smaller than or equal to 30 degrees, the elastic modulus of the carbon fibers is large, so that the elastic modulus of the composite material can be improved, the vibrating plate has high elastic modulus and structural strength, and the high-frequency acoustic performance of the sound generating device provided with the vibrating plate is improved.

Optionally, the carbon fiber form factor ranges from 0.1 to 1.5.

Specifically, the shape factor is a ratio of a packing thickness of graphite crystallites in the carbon fiber to a basal plane width of the graphite crystallites. When the orientation angle of the carbon fiber is fixed, the elastic modulus of the carbon fiber decreases as the form factor increases. When the shape factor of the carbon fiber is 0.1-1.5, the elastic modulus of the carbon fiber is high, and the ratio of the elastic modulus to the tensile strength of the carbon fiber is also high, so that the elastic modulus of the composite material can be improved, and the vibrating plate has high elastic modulus and structural strength.

Optionally, the carbon fibers are chopped carbon fibers, the diameter of the chopped carbon fibers ranges from 3 μm to 100 μm, and the length of the chopped carbon fibers ranges from 0.1mm to 20 mm.

Specifically, the chopped carbon fibers are formed by chopping carbon fiber filaments through a fiber cutting machine, and the chopped carbon fibers have the advantages of uniform dispersion, various feeding modes, simple process and the like, so that the application range of the chopped carbon fibers is widened. In the forming process of the composite material, the chopped carbon fibers are mixed with the polymer matrix, and the chopped carbon fibers can be uniformly dispersed in the polymer matrix through the interface infiltration effect of the polymer matrix, so that the performances of the composite material, such as tensile strength, bending modulus and the like, are remarkably improved, and the modulus and strength of the vibrating plate are also improved. The relationship between the length of the carbon fiber and the elastic modulus of the vibration plate is given in table 1, and it can be seen from the table that the elastic modulus of the vibration plate increases as the length of the carbon fiber increases. Particularly, in the process of increasing the length of the carbon fiber from 0.1mm to 20mm, the modulus (particularly, the bending modulus) of the vibration plate is increased from 3.41GPa to 4.93GPa, and the structural strength of the vibration plate is remarkably improved. When the length of the carbon fiber is greater than 20mm, for example, the length of the carbon fiber is 25mm, the modulus of the vibrating plate is 4.89Gpa, which is substantially equivalent to 4.93Gpa when the length of the carbon fiber is 20 mm. When the carbon fiber is excessively long, the uniformity of the carbon fiber dispersed in the polymer matrix is poor when the vibration plate is molded, resulting in an increase in the defective rate of the vibration plate.

TABLE 1 relationship between carbon fiber length and diaphragm modulus

Carbon fiber length (mm)	Modulus of vibrating plate (GPa)
		0.1	3.41
0.7	3.65
		10	4.37
20	4.93
		25	4.89

Alternatively, the modulus of the vibration plate is greater than or equal to 2.5GPa, and the modulus may be an elastic modulus, specifically including a flexural modulus, a compressive modulus, and a shear modulus.

Specifically, the modulus of general plastics or rubber is approximately 1GPa-2GPa, which is not enough to meet the vibration requirement of the vibrating plate. The carbon fiber reinforced material is dispersed in the polymer matrix to form the composite material, and the vibrating plate obtained by the composite material has higher modulus which can reach 2.5GPa or even higher. When the modulus of the vibration plate is increased, the acoustic Fh (high frequency resonance peak) of the vibration plate is delayed, and the Fr (frequency loudness curve) flatness and frequency loudness of the vibration plate are increased, so that the sound production device provided with the vibration plate has high-frequency sound production quality. Fig. 2 is a graph comparing the Fr test curves of the vibrating plate provided in the embodiment of the present application and the conventional vibrating plate, in which the vibrating plate provided in the embodiment of the present application is a single-layer vibrating plate, the single-layer vibrating plate is entirely made of a composite material, the mass fraction of the carbon fiber reinforcing material in the composite material is 35%, the carbon fibers are chopped carbon fibers, the diameter of the chopped carbon fibers is 8 μm, the length of the chopped carbon fibers is 1.2mm, and the polymer matrix is polypropylene. A conventional vibration plate employs a plastic vibration plate. As can be seen from the figure, the vibration plate Fh provided by the embodiment of the present application is approximately at 16000Hz, as shown at a in fig. 2; whereas Fh of the conventional vibrating plate is only at 13000Hz, as shown at b in fig. 2.

Optionally, the vibration plate is formed by injection molding.

Specifically, in the injection molding process of the vibrating plate, the melting plasticization and the flow molding of the vibrating plate raw material can be respectively carried out in the charging barrel and the die cavity, and the die forming the die cavity can be always in a state that the raw material solution is rapidly cooled and molded, so that the molding cycle of the vibrating plate is greatly shortened. Meanwhile, on the premise of ensuring the good processing flowability of the raw materials, the die can be precisely processed to obtain a vibrating plate product with better dimensional stability.

Optionally, the vibrating plate is a single-layer vibrating plate, and the single-layer vibrating plate is made of the composite material;

or the vibration plate is a composite vibration plate, the composite vibration plate comprises at least two layers, and at least one layer of the composite vibration plate comprises the composite material.

Specifically, when the vibrating plate is a single-layer vibrating plate, the single-layer vibrating plate may be made of the composite material to ensure the modulus and structural strength of the single-layer vibrating plate. When the vibrating plate is a composite vibrating plate, namely the vibrating plate comprises a plurality of layers, one layer can be made of the composite material, and the other layers are made of polymer materials such as plastics or rubber; for example, when the number of layers of the vibration plate is greater than two, the two layers made of the composite material may be located on the inner side and the outer side of the vibration plate, and further sandwich other layers therebetween, so as to enhance the strength of the exposed layer of the vibration plate. In addition, when the vibrating plate comprises a plurality of layers, the layers can be compositely bonded by adopting glue layers, so that the aim of fixing the vibrating plate structure is fulfilled.

Optionally, the thickness of the single-layer vibrating plate ranges from 50 μm to 2800 μm, and preferably ranges from 100 μm to 2000 μm.

Specifically, when the thickness of the single-layer vibrating plate is too low, the modulus and the structural strength of the single-layer vibrating plate are low, and the single-layer vibrating plate is damaged in the vibrating process; when the thickness of the single-layer diaphragm is too high, although the modulus and the structural strength of the single-layer diaphragm are sufficiently large, the sound production sensitivity of the speaker is affected by the excessive weight of the diaphragm, and the sound production effect of the speaker is affected. Vibrating plate

The embodiment of the application also provides a sound generating device, including vibration system and with the magnetic circuit that vibration system mutually supported, vibration system include the vibration board.

Specifically, the vibration plate is made of a composite material, and the composite material disperses the carbon fiber reinforcing material in the polymer matrix, so that the modulus and the structural strength of the vibration plate are enhanced, the sound generating device has a wider frequency response range and lower distortion, and the sound generating effect of the sound generating device is improved.

Although some specific embodiments of the present application have been described in detail by way of example, 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 application. 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 application. The scope of the application is defined by the appended claims.