JP2022154778A - Speaker diaphragm, speaker, electronic device, and moving body - Google Patents

Abstract

To provide a speaker diaphragm capable of achieving satisfactory characteristics and high sound quality by achieving high performance with high rigidity and high elastic modulus, and the manufacturing method thereof.SOLUTION: The manufacturing method of a speaker diaphragm is a method to obtain a sheet-like resin member by mixing carbon fiber 27B into thermoplastic epoxy resin 27A using a papermaking method. The obtained sheet-shaped resin member is further heat-press molded into the shape of the speaker diaphragm 27.EFFECT: In addition to the high rigidity and elastic modulus of the base thermoplastic epoxy resin 27A, the rigidity and the elastic modulus can be furthermore increased by mixing carbon fiber 27B. With this, a speaker diaphragm 27 capable of achieving high sound quality can be obtained.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to speaker diaphragms used in various audio equipment, speakers using the same, and electronic equipment and mobile bodies using the speaker.

A conventional technique will be described with reference to FIG. FIG. 6 is a cross-sectional view of a conventional injection-molded resin speaker diaphragm.

As shown in FIG. 6, the loudspeaker diaphragm 27 is obtained by hot-melting resin pellets in a mold having a predetermined shape and injection molding the melted resin pellets. A single material such as polypropylene is generally used as the type of resin material for these injection moldings.

In addition, a blend type resin material in which different types of resin are mixed is sometimes used for the purpose of adjusting the physical properties of the speaker diaphragm, that is, adjusting the characteristics and sound quality of the speaker.

Furthermore, in order to adjust the physical property values, which are difficult to adjust with these resin materials, reinforcing materials are mixed in to adjust the physical property values, and the speaker characteristics and sound quality are adjusted.

For example, Patent Document 1 and Patent Document 2 are known as prior art document information related to the invention of this application.

JP-A-2005-238758 JP-A-55-115794

In general, polypropylene is often used as the base resin for blend-type resin materials. When polypropylene is used as the base resin, it is inexpensive and has good productivity, but has the problem of low rigidity and elastic modulus as a speaker diaphragm.

In order to improve rigidity and elastic modulus, fibrous reinforcing materials are sometimes mixed, but the fibrous reinforcing materials are crushed finely by the screw during injection molding, and the original fibrous reinforcing materials There was a problem that it was not possible to take full advantage of the performance of

Therefore, the present disclosure solves this problem, and provides a speaker diaphragm that has high rigidity and elastic modulus and can achieve high sound quality, a speaker that includes the speaker diaphragm, an electronic device that includes the speaker, and a moving object. It is intended to

In order to achieve this object, the present disclosure comprises a loudspeaker diaphragm by mixing carbon fiber into a thermoplastic epoxy resin.

In order to achieve this object, another aspect of the present disclosure includes a magnetic circuit, a frame coupled with the magnetic circuit, a speaker diaphragm coupled to an outer peripheral portion of the frame, and the speaker vibration. a voice coil coupled to a plate and having a portion of the speaker diaphragm positioned in the magnetic gap of the magnetic circuit, wherein the speaker diaphragm is made of carbon in thermoplastic epoxy resin; A speaker composed of mixed fibers.

In order to achieve this object, another aspect of the present disclosure is an electronic device including a speaker and an amplifier circuit for an input signal to the speaker, wherein the speaker includes a magnetic circuit and the magnetic circuit. a speaker diaphragm coupled to the outer periphery of the frame; and a speaker diaphragm coupled to the speaker diaphragm, a portion of the speaker diaphragm being disposed in the magnetic gap of the magnetic circuit. and a voice coil, wherein the speaker diaphragm is formed by mixing carbon fiber into a thermoplastic epoxy resin.

In order to achieve this object, another aspect of the present disclosure is a moving object including a speaker, a housing to which the speaker is attached, and driving means for moving the speaker and the housing. a frame coupled to the magnetic circuit; a speaker diaphragm coupled to an outer peripheral portion of the frame; a speaker diaphragm coupled to the speaker diaphragm; and a voice coil part of which is arranged in the magnetic gap of the magnetic circuit, and the speaker diaphragm is made of thermoplastic epoxy resin mixed with carbon fiber.

As described above, according to the present disclosure, the carbon fiber can be uniformly blended by mixing the carbon fiber, which has a good affinity, with the thermoplastic epoxy resin to improve the dispersibility. Therefore, in addition to the high rigidity and elastic modulus of the thermoplastic epoxy resin used as the base, the rigidity and elastic modulus can be increased by mixing carbon fibers, and a speaker diaphragm capable of realizing high sound quality can be obtained.

2 is a cross-sectional view of the speaker diaphragm in Embodiment 1. FIG. 2 is a plan view of the speaker diaphragm in Embodiment 1. FIG. FIG. 10 is a cross-sectional view of a speaker according to Embodiment 2; FIG. 11 is an external view of an electronic device according to Embodiment 3; FIG. 11 is a cross-sectional view of a moving body according to Embodiment 4; FIG. 2 is a cross-sectional view of a conventional speaker diaphragm;

Embodiments of the present disclosure will be described below with reference to the drawings.

(Embodiment 1)
The present disclosure will be described below using Embodiment 1. FIG.

FIG. 1 shows a cross-sectional view of a diaphragm of one embodiment of the present disclosure. FIG. 2 illustrates a plan view of a diaphragm of one embodiment of the present disclosure. As shown in FIGS. 1 and 2, speaker diaphragm 27 is formed by mixing carbon fiber 27B into thermoplastic epoxy resin 27A.

In the case of this embodiment, a sheet-like resin member is obtained by mixing carbon fiber 27B into thermoplastic epoxy resin 27A by a papermaking method. The obtained sheet-shaped resin member is further heat-press-molded into the shape of the loudspeaker diaphragm 27 . By manufacturing the speaker diaphragm 27 by such a manufacturing method, the carbon fibers 27B can be uniformly dispersed in the thermoplastic epoxy resin 27A. The thermoplastic epoxy resin 27A is used because it has good compatibility with the carbon fiber 27B in the papermaking method and has a good familiarity. Therefore, in addition to the high rigidity and elastic modulus of the thermoplastic epoxy resin 27A serving as the base, the rigidity and elastic modulus can be increased by mixing the carbon fiber 27B, thereby obtaining the speaker diaphragm 27 capable of realizing high sound quality. can be done.

In addition, by adopting such a manufacturing method, the carbon fiber 27B as a reinforcing material is finely crushed by the screw during injection molding as in the conventional manufacturing method by injection molding, and the original performance of the reinforcing material is lost. You can solve the problem that you can't make the most of it.

Furthermore, conventionally, a base resin that is not compatible with or familiar with the carbon fiber 27B is used. In this case, if a sheet made of a conventional resin material is heat-pressed to stretch the material and then molded into the shape of the speaker diaphragm, the carbon fibers 27B are entangled with each other, resulting in poor dispersibility. There is a problem that the carbon fiber 27B becomes uneven in the speaker diaphragm 27, and the speaker diaphragm 27 is cracked or torn. In the case of the present embodiment, by using the thermoplastic epoxy resin 27A as the base resin, it is possible to solve the uneven distribution of the carbon fibers 27B and the occurrence of cracks and breakage of the speaker diaphragm 27. FIG.

Further, the epoxy resin employed in the present embodiment is thermoplastic epoxy resin 27A instead of thermosetting epoxy resin. For this reason, hot press molding becomes possible, and the carbon fiber 27B can be uniformly dispersed and blended with the thermoplastic epoxy resin 27A. Mixing 27B produces a great effect that the rigidity and elastic modulus can be increased.

Next, detailed contents will be described.

The mixing ratio of the carbon fiber 27B to the thermoplastic epoxy resin 27A is selected from the range of 10% by weight or more and 50% by weight or less. By setting this mixing ratio, it is possible to obtain the necessary properties in a well-balanced manner, and it is possible to obtain the effect of realizing high rigidity and elastic modulus. If the mixing ratio of the carbon fibers 27B to the thermoplastic epoxy resin 27A is less than 10%, there is a possibility that the carbon fibers 27B are less effective in improving the rigidity and elastic modulus of the thermoplastic epoxy resin 27A. Therefore, it becomes difficult to obtain the desired sound quality and characteristics of the speaker diaphragm 27 . On the other hand, when the mixing ratio of the carbon fiber 27B to the thermoplastic epoxy resin 27A is more than 50%, productivity tends to decrease.

The fiber length distribution of the mixed carbon fibers 27B is a distribution in which the length selected from the range of 2 mm or more and 10 mm or less becomes a peak. By using the carbon fibers 27B having fiber lengths with such a distribution, the carbon fibers 27B have good dispersibility when compounded with the thermoplastic epoxy resin 27A while maintaining the high rigidity and elastic modulus of the carbon fibers 27B. can be uniformly blended into the thermoplastic epoxy resin 27A, and the composite effect is efficiently exhibited. As a result, it is possible to increase the rigidity and elastic modulus of the obtained speaker diaphragm 27, which is a great effect.

If the peak of the fiber length distribution of the mixed carbon fibers 27B is shorter than 2 mm, the effects of the carbon fibers 27B cannot be efficiently exhibited, and significant improvement in rigidity and elastic modulus cannot be expected. On the other hand, if the peak of the fiber length distribution of the mixed carbon fibers 27B is longer than 10 mm, aggregates of the carbon fibers 27B appear on the surface of the speaker diaphragm 27, which tends to impair the appearance, resulting in poor productivity and quality. tends to decrease.

Using PP (polypropylene) resin, PET (polyethylene terephthalate) resin, and ABS (acrylonitrile butadiene styrene) resin as base resin materials, carbon fiber is mixed to create a speaker diaphragm, and carbon fiber is added to thermoplastic epoxy resin. Table 1 shows the results of comparison with a speaker diaphragm made by mixing

From Table 1, it is clear that the speaker diaphragm 27 using the thermoplastic epoxy resin 27A as the base resin has an improved elastic modulus compared to the speaker diaphragm using other types of resins as the base resin. There is a trend toward higher sound quality. More specifically, the speaker diaphragm 27 with the thermoplastic epoxy resin 27A as the base resin has about twice as much power as the speaker diaphragm with the PP resin as the base resin, and about twice as much as the speaker diaphragm with the PET resin as the base resin. A high elastic modulus of 1.5 times was obtained. In addition, it was possible to obtain a higher elastic modulus than the speaker diaphragm using ABS resin as the base resin.

As described above, the present disclosure is a speaker diaphragm based on a resin material in which carbon fiber 27B is mixed with thermoplastic epoxy resin 27A. As a result, the carbon fibers 27B can be mixed uniformly with the thermoplastic epoxy resin 27A by mixing the carbon fibers 27B, which are well-suited to each other, into the thermoplastic epoxy resin 27A to improve dispersibility. For this reason, even if the material is stretched and formed into the shape of the speaker diaphragm 27 during hot press molding, the carbon fibers 27B become uneven, and cracks and tears occur in the speaker diaphragm. You can get rid of it without a hitch. Therefore, in addition to the high rigidity and modulus of elasticity of the thermoplastic epoxy resin 27A serving as the base, the rigidity and modulus of elasticity can be increased by mixing the carbon fiber 27B, and a speaker diaphragm capable of realizing high sound quality can be obtained. can.

Also, a sheet-shaped resin member obtained by mixing the thermoplastic epoxy resin 27A and the carbon fiber 27B by a papermaking method is heat-press-molded into the shape of the speaker diaphragm 27. The screw does not crush the carbon fibers 27B finely. Thereby, it is possible to obtain the speaker diaphragm 27 in which the original performance of the carbon fiber 27B as a reinforcing material can be fully exhibited.

Further, as means for adjusting the physical properties of the speaker diaphragm 27, a resin other than the thermoplastic epoxy resin may be further mixed. As the resin other than the thermoplastic epoxy resin to be mixed, it is preferable to select a resin softer than the thermoplastic epoxy resin 27A. As a result, it is possible to easily adjust the sound quality and acoustic characteristics such as suppressing excessive height of the rigidity and elastic modulus. Resins softer than the thermoplastic epoxy resin 27A include PP (polypropylene) resin, PET (polyethylene terephthalate) resin, ABS (acrylonitrile butadiene styrene) resin, and the like.

Moreover, not only one type of these relatively soft resins but also a plurality of types may be blended and mixed. By blending and mixing multiple types of resins, it is possible to reflect the physical properties of each resin, so it is possible to finely adjust the sound quality and acoustic characteristics. Therefore, by mixing these relatively soft resins, the compatibility with the carbon fibers 27B, which has not been good in the past, is improved due to the presence of the thermoplastic epoxy resin 27A. The fibers 27B can be uniformly dispersed and blended. Then, a manufacturing method is adopted in which a sheet formed by mixing these relatively soft resins by a paper-making method is heated and press-molded into the shape of a speaker diaphragm, thereby uniformly dispersing the carbon fibers 27B. can be blended together. Furthermore, by using this manufacturing method, the peak of the fiber length distribution of the carbon fibers 27B can be within the range of 2 mm or more and 10 mm or less, so that the effects of the carbon fibers 27B can be fully exhibited. .

As described above, by mixing these relatively soft resins, it is possible to finely adjust the physical properties of the speaker diaphragm in addition to the mixing effect of the thermoplastic epoxy resin 27A and the carbon fiber 27B. , desired sound quality and acoustic characteristics can be realized.

(Embodiment 2)
The present disclosure will be described below using Embodiment 2. FIG.

FIG. 3 shows a sectional view of the loudspeaker according to the second embodiment. As shown in FIG. 3, a magnetized magnet 21 is sandwiched between an upper plate 22 and a yoke 23 to form an internal magnet type magnetic circuit 24 .

Yoke 23 of magnetic circuit 24 is coupled to frame 26 . An edge 27 e of the speaker diaphragm 27 described in the first embodiment is adhered to the peripheral edge portion 26 a of the frame 26 . A center portion of the speaker diaphragm 27 is coupled to one end of the voice coil body 28 . The other end of the voice coil body 28 is arranged so as to fit into the magnetic gap 25 of the magnetic circuit 24 . In this embodiment, the voice coil body 28 includes the voice coil 28a and the bobbin 28b around which the voice coil 28a is wound, but the voice coil body 28 without the bobbin 28b may also be used.

Although the speaker 10 having the inner magnetic circuit 24 has been described in the second embodiment, the present invention is not limited to this, and may be applied to the speaker 10 having an outer magnetic circuit.

According to the speaker 10 described in Embodiment 2, it is possible to realize a speaker with good characteristics and good sound quality. In particular, since the rigidity and elastic modulus of the speaker diaphragm 27 can be increased, it is possible to achieve an improvement in the upper limit frequency in terms of the characteristics of the speaker.

As for the sound quality of the speaker 10, high-fidelity reproduction and high-definition sound quality can be realized due to the improved rigidity and elastic modulus of the speaker diaphragm 27 (Embodiment 3).
The present disclosure will be described below using a third embodiment.

FIG. 4 shows an external view of an audio mini-component system, which is an electronic device according to an embodiment of the present disclosure.

The speaker 10 is incorporated in the enclosure 11 to configure a speaker system 16 .

The amplifier 12 is an electronic device including a circuit for amplifying electric signals input to the speaker system 16 . An operation unit 13 such as a player outputs a source input to an amplifier 12 which is an amplifying circuit. The audio mini-component system 14, which is an electronic device, has the amplifier 12, the operating section 13, and the speaker system 16 as described above. The amplifier 12, the operation section 13, and the enclosure 11 are the main body of the mini component system 14. FIG. That is, the speaker 10 is attached to the main body of the mini component system 14 .

The voice coil body 28 of the speaker 10 is supplied with power from the amplifier 12 of the main body, vibrates the speaker diaphragm 27, and emits sound. As a result, the mini-component system 14 can be obtained, which enables high-fidelity reproduction, high-definition sound quality, and excellent characteristics, which have not been possible in the past.

(Embodiment 4)
The present disclosure will be described below using Embodiment 4. FIG.

FIG. 5 shows a cross-sectional view of an automobile 15, which is a moving body according to the fourth embodiment. As shown in FIG. 5, an automobile 15, which is a moving object, has the speaker 10 described in the second embodiment on its rear tray, front panel, or the like. The speaker 10 is used as part of car navigation and car audio. The automobile 15 includes a driving means 15a to move the speaker 10 together with a vehicle body 15b functioning as a housing for accommodating the speaker 10. As shown in FIG.

As a result, by utilizing the features of the speaker 10, it is possible to realize a moving object such as an automobile that is capable of high-fidelity reproduction, good sound quality with high clarity, and good characteristics.

A loudspeaker diaphragm, a loudspeaker, an electronic device, and a moving object according to the present disclosure can be applied to electronic devices that require high sound quality, as well as devices such as automobiles.

10 Speaker 11 Enclosure 12 Amplifier 13 Operation Unit 14 Mini Component System 15 Car 15a Driving Means 15b Car Body 16 Speaker System 21 Magnet 22 Top Plate 23 Yoke 24 Magnetic Circuit 25 Magnetic Gap 26 Frame 26a Periphery 27 Speaker Diaphragm 27A Thermoplastic Epoxy Resin 27e edge 28 voice coil body 28a voice coil 28b bobbin

Claims (10)

A loudspeaker diaphragm made of thermoplastic epoxy resin containing carbon fiber. 2. The loudspeaker diaphragm according to claim 1, wherein the content ratio of carbon fiber to said thermoplastic epoxy resin is 10% by weight or more and 50% by weight or less. 3. The loudspeaker diaphragm according to claim 1, wherein the fiber length distribution of the carbon fibers has a peak at a length selected from a range of 2 mm or more and 10 mm or less. 4. The loudspeaker diaphragm according to claim 1, further comprising a resin other than said thermoplastic epoxy resin. 5. The speaker diaphragm according to claim 4, wherein the resin other than the thermoplastic epoxy resin is a polypropylene resin. A method of manufacturing a speaker diaphragm by mixing carbon fiber into a thermoplastic epoxy resin by a papermaking method. 7. The method for producing a loudspeaker diaphragm according to claim 6, wherein the sheet-shaped resin member obtained by the papermaking method is heat-press molded. a magnetic circuit;
a frame coupled with the magnetic circuit;
a speaker diaphragm according to any one of claims 1 to 5, which is coupled to the outer peripheral portion of the frame;
a voice coil coupled to the speaker diaphragm and having a portion of the speaker diaphragm disposed in the magnetic gap of the magnetic circuit;
A speaker with a A speaker according to claim 8;
an amplifier circuit for an input signal to the speaker;
electronic equipment. A speaker according to claim 8;
a housing to which the speaker is attached;
driving means for moving the speaker and the housing;
A mobile body with

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