JP2011109722A - Speaker frame, speaker with the same, electronic apparatus, and moving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightweight speaker frame having high rigidity and a speaker with the same that are used for audio equipment. <P>SOLUTION: The speaker frame is a resin frame for a speaker that is obtained by injection molding. The frame is the speaker frame with at least resin and cellulose fiber. The cellulose fiber is bamboo fiber that includes bamboo fiber that is micronized to a microfibril state to comprise the speaker frame, thereby achieving the productive speaker frame that has lightweight, high rigidity, high internal loss, and superior appearance. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a speaker frame, a speaker using the same, an electronic device, and a moving device.

  In order to prevent the vibration of the diaphragm from being transmitted to the magnetic circuit or to be difficult to resonate, the speaker frame is required to have high rigidity, vibration suppression effect, and high internal loss. Resins have been used.

  However, the iron plate has a problem that the magnetic leakage is large and the appearance is lacking in a high-class appearance, and the aluminum die-casting has the disadvantage that it is excellent in magnetic leakage and appearance quality, is high in rigidity but very expensive. Therefore, recently, in order to solve this problem, a thermoplastic synthetic resin is often used by being molded into the shape of a speaker frame by injection molding. In particular, in the case of a resin frame, the degree of freedom of shape is large, and it is also suitable for weight reduction that has recently been required.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2003-37891 A

  A conventional resin speaker frame can be reduced in weight, but an inorganic filler such as glass fiber or mica is added because the rigidity of the base resin alone is low. In particular, polypropylene having a small specific gravity and a large internal loss is used because of its light weight, moldability, and acoustic performance. However, in order to satisfy the acoustic performance, it is necessary to add an inorganic filler with a weight ratio of 30% or more. However, when an inorganic filler is added, the rigidity increases, but the specific gravity also increases, so the weight of the frame increases. Further, since the internal loss is reduced, the effect of absorbing unnecessary vibration is reduced.

  Therefore, an object of the present invention is to provide a speaker frame that realizes light weight, high rigidity, and high internal loss.

  In order to achieve the above object, the present invention provides a speaker frame comprising a resin and bamboo fiber, wherein the bamboo fiber has a fiber length of 0.2 mm or more and 3 mm or less, and the mixing ratio into the resin is 15 wt. % To 70% by weight, the average fiber diameter is 10 μm or less, and the microfibril state is partially refined.

  With this configuration, the use of bamboo fiber is lighter than the conventional resin frame, and the internal loss is increased while maintaining sufficient rigidity. Therefore, resonance is reduced, the sound pressure-frequency characteristics are flattened, and distortion is reduced. In addition, by including bamboo fiber that has been refined into a microfibril state in a part of the bamboo fiber, a speaker frame with higher strength and greater rigidity can be obtained.

Sectional drawing of the flame | frame for speakers in one embodiment of this invention Sectional drawing of the speaker in one embodiment of this invention 1 is an external view of an electronic device according to an embodiment of the present invention. Sectional drawing of the moving apparatus in one embodiment of this invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
Hereinafter, the present invention will be described using the first embodiment. FIG. 1 is a sectional view of a speaker frame according to an embodiment of the present invention.

  The frame 1 is formed by injection molding a material in which bamboo fiber 1C partially mixed to a microfibril state is mixed with resin 1A and bamboo fiber 1B. Here, the bamboo fiber functions to improve the rigidity of the resin alone, and the rigidity is further improved by including the bamboo fiber refined to a microfibril state. Moreover, it can be light and have a large internal loss as compared with an inorganic filler.

  The speaker frame of the present invention uses an olefin resin as the resin 1A. By using an olefin-based resin, moldability can be improved. In particular, when polypropylene is used, a frame having a large internal loss can be obtained.

  In addition, a speaker frame with improved heat resistance can be obtained by using engineering plastic. In addition, by using a biodegradable plastic, it is possible to provide an environment-friendly high performance speaker frame that can avoid discharge of excess carbon dioxide during disposal. In addition, polylactic acid is more transparent and rigid than other biodegradable plastics, and a high-rigidity and environmentally friendly speaker frame is possible without impairing the appearance color of bamboo fiber.

  This time, the resin 1A will be described with respect to an example in which polypropylene is used. A pellet was prepared by kneading bamboo fiber and bamboo fiber and a reinforcing material into polypropylene, and a plate having a thickness of 0.3 mm was formed from the pellet by injection molding. Then, after measuring the specific gravity, a sample having a size of 32 mm × 5 mm, which is a part of the sample, is extracted, the elastic modulus and the internal loss are measured, and compared with the characteristics of a resin mixed with a conventional reinforcing material, The result was obtained.

  As is clear from Table 1, the frame material according to the present invention has a small specific gravity, and has a higher elastic modulus and higher internal loss than conventional resin frames with reinforcing materials. It turns out that it is obtained.

  Here, since bamboo fiber has a large internal loss, it has a large effect of absorbing unnecessary vibrations, and the elastic modulus can be improved more than the resin alone. Furthermore, by using bamboo fibers that are partially refined to a microfibril state, the entanglement of the fibers is strengthened, and a speaker frame with higher strength and rigidity can be obtained.

  In addition, as for the bamboo fiber used here, it is desirable for fiber length to be 0.2 mm or more and 3 mm or less. If the bamboo fibers are longer than 3 mm, poor dispersion occurs during kneading with the resin, or poor appearance of the molded product due to secondary aggregation of the long fibers. On the other hand, if the bamboo fiber is shorter than 0.2 mm, sufficient strength cannot be obtained, and the effect of the bamboo fiber cannot be obtained.

  In addition, bamboo fibers refined to a microfibril state are not entangled when the fiber diameter is larger than 10 μm, and the fiber itself generally has a higher elastic modulus as the aspect ratio (fiber length / fiber diameter) increases.

  Furthermore, it becomes possible to mix bamboo fiber 60weight% or more by using bamboo powder for bamboo fiber. Moreover, since bamboo powder is more dispersible than fiber, it is possible to uniformly disperse up to 70% by weight bamboo fiber, and to obtain a speaker frame with excellent appearance in which bamboo fiber is uniformly dispersed at a high concentration. be able to.

  Furthermore, the mixing ratio of bamboo fiber is preferably 15% by weight or more and 70% by weight or less, but when bamboo powder is not used, it is preferably 15% by weight or more and 60% by weight or less. With this configuration, it is possible to efficiently draw out the effects when kneaded with the resin, and to improve productivity and quality.

  This is because when the bamboo fiber is less than 15% by weight, the high elasticity and high strength, which are the characteristics of the bamboo fiber, cannot be exhibited, and when it is more than 70% by weight, uniform dispersion is difficult and the fluidity is lowered. Is difficult, the productivity is lowered, and the degree of freedom in shape is reduced.

  Furthermore, when raising the elasticity modulus of a flame | frame, it can also be comprised by mixing in glass fiber, mica, or what combined these as a reinforcing material.

  In this case, in order to obtain a sufficient elastic modulus in the speaker frame, it is desirable to mix 10% by weight or more of a reinforcing material. Further, although the elastic modulus improves as the mixing ratio of the reinforcing material increases, the specific gravity increases and the internal loss decreases.

  In addition to the above, the reinforcing material can also contain so-called inorganic fillers such as talc, graphite, and glass flakes, and organic fibers such as aramid fibers and carbon fibers. In addition, when an aramid fiber that has been refined to a microfibril state is used as the aramid fiber, the entanglement between the fibers is improved, and a speaker frame with higher strength and higher rigidity can be obtained.

  Then, by mixing hydrolyzable long-chain alkylsilane as a compatibilizing agent, the olefin resin and bamboo fiber can be bound more firmly. Especially when the carbon number of the alkyl group is 6 or more, the carbon chain is long, so it is effective to bind the olefin resin and bamboo fiber particularly firmly, and it is lightweight and highly rigid utilizing the properties of bamboo fiber. A speaker frame can be obtained. The hydrolyzable long-chain alkylsilane used here is more effective as hexyltrimethoxysilane or decyltrimethoxysilane, but a silane coupling agent or acid-modified polypropylene resin can also be used.

  As described above, the present invention is a speaker frame including a resin and a cellulose fiber, and the cellulose fiber is made of bamboo fiber, thereby having low specific gravity, high elastic modulus, high internal loss, and high quality. A speaker frame having excellent productivity can be obtained.

(Embodiment 2)
Hereinafter, the present invention will be described using the second embodiment. FIG. 2 is a sectional view of the speaker 10 according to the embodiment of the present invention.

  As shown in FIG. 2, a magnetized magnet 2 is sandwiched between an upper plate 3 and a yoke 4 to form an internal magnet type magnetic circuit 5. Any one of the frames 1 to 14 is coupled to the yoke 4 of the magnetic circuit 5. The outer periphery of the diaphragm 7 is bonded to the peripheral edge of the frame 1 via the edge 9. One end of the voice coil 8 is coupled to the central portion of the diaphragm 7 and the other end is coupled so as to fit into the magnetic gap 6 of the magnetic circuit 5. In the above, the speaker having the inner magnet type magnetic circuit 5 has been described. However, the present invention is not limited to this, and the present invention may be applied to a speaker having an outer magnet type magnetic circuit.

  With this configuration, as described in the first embodiment, a lightweight speaker with excellent appearance and high productivity can be realized by using a speaker frame having a low specific gravity, a high elastic modulus, and a high internal loss. Can do.

(Embodiment 3)
Hereinafter, the present invention will be described using the third embodiment. FIG. 3 is an external view of an audio minicomponent system that is an electronic apparatus according to an embodiment of the present invention.

  The speaker 10 is incorporated in the enclosure 11 to constitute a speaker system 21. The amplifier 12 includes an amplification circuit for an electric signal input to the speaker system 21. An operation unit 13 such as a player outputs a source input to the amplifier 12. As described above, the audio mini-component system 14 that is an electronic device includes the amplifier 12, the operation unit 13, and the speaker system 21. The amplifier 12, the operation unit 13, and the enclosure 11 are main body units of the mini component system 14. That is, the speaker 10 is attached to the main body of the mini component system 14. The voice coil of the speaker 10 is supplied with power from the amplifier 12 of the main body and emits sound from the diaphragm. With this configuration, it is possible to obtain a mini component system 14 that enables high-precision characteristic creation, sound creation, and design that could not be realized in the past.

  In addition, although the audio | voice minicomponent system 14 was demonstrated as an application to the apparatus of the speaker 10, it is not limited to this. Application to portable devices that can be carried is also possible. Furthermore, it can be widely applied and deployed in video equipment such as liquid crystal televisions and plasma display televisions, information communication equipment such as mobile phones, and electronic equipment such as computer-related equipment.

(Embodiment 4)
Hereinafter, the present invention will be described using the fourth embodiment. FIG. 4 shows a cross-sectional view of an automobile 15 which is a moving apparatus according to an embodiment of the present invention.

  As shown in FIG. 4, an automobile 15 is configured by incorporating the speaker 10 of the present invention into a rear tray or a front panel and using it as a part of car navigation or car audio. By adopting this configuration, it is possible to improve the appearance quality, characteristics, and sound quality of mobile devices such as automobiles equipped with the speaker 10 by creating highly accurate characteristics, making sound, and designing using the features of the speaker 10. Can be improved.

  The speaker frame, the speaker, the electronic device, and the moving device according to the present invention can be applied to an electronic device such as an audiovisual device or an information communication device that requires high-precision characteristics and sound creation, and further to a device such as an automobile.

DESCRIPTION OF SYMBOLS 1 Frame 1A Resin 1B Bamboo fiber 1C Bamboo fiber refined to microfibril state 2 Magnet 3 Upper plate 4 Yoke 5 Magnetic circuit 6 Magnetic gap 7 Diaphragm 8 Voice coil 9 Edge 10 Speaker 11 Enclosure 12 Amplifier 13 Operation unit 14 Mini component system 15 Car 21 Speaker system

Claims (18)

A speaker frame including a resin and bamboo fiber, wherein the bamboo fiber has a fiber length of 0.2 mm to 3 mm, a mixing ratio in the resin of 15 wt% to 70 wt%, and an average fiber A speaker frame having a diameter of 10 μm or less and partially miniaturized to a microfibril state. The speaker frame according to claim 1, wherein the speaker frame is formed by injection molding. The speaker frame according to claim 1, wherein the resin is a crystalline or amorphous olefin resin. The speaker frame according to claim 1, wherein the resin is polypropylene. The speaker frame according to claim 1, wherein the resin is engineering plastic. The speaker frame according to claim 1, wherein the resin is a biodegradable plastic. The speaker frame according to claim 1, wherein the biodegradable plastic is polylactic acid. The speaker frame according to claim 1, wherein at least a part of the bamboo fiber is bamboo powder. The speaker frame according to claim 1, further comprising a reinforcing material. The speaker frame according to claim 9, wherein the reinforcing material is one of glass fiber, mica, aramid fiber, carbon fiber, or a combination thereof. The speaker frame according to claim 10, wherein the aramid fiber is treated so as to at least partially become fine to a microfibril state. The speaker frame according to claim 1, further comprising a compatibilizing agent that improves the adhesion between the resin and the bamboo fiber. The speaker frame according to claim 12, wherein the compatibilizing agent is a hydrolyzable long-chain alkylsilane. The speaker frame according to claim 13, wherein the hydrolyzable long-chain alkylsilane has 6 or more carbon atoms. The speaker frame according to claim 1 coupled to a magnetic circuit and the magnetic circuit; a diaphragm coupled to an outer peripheral portion of the frame; and a portion coupled to the diaphragm, and a part of the diaphragm being coupled to the magnetic circuit. A speaker comprising: a voice coil disposed within a range of action of magnetic flux generated from a circuit. The speaker frame according to claim 1, which is coupled to the main body, the magnetic circuit, and the magnetic circuit, and the diaphragm coupled to the outer peripheral portion of the frame and the diaphragm, and a part of the diaphragm is coupled to the diaphragm. An electronic apparatus comprising: a voice coil disposed within a range of action of magnetic flux generated from a magnetic circuit; and a speaker fed from the main body. The electronic device according to claim 16, wherein the main body includes at least a circuit that amplifies an input signal to the speaker. The speaker frame according to claim 1 coupled to a magnetic circuit and the magnetic circuit; a diaphragm coupled to an outer peripheral portion of the frame; and a portion coupled to the diaphragm, and a part of the diaphragm being coupled to the magnetic circuit. A moving device equipped with a speaker including a voice coil arranged within an action range of magnetic flux generated from a circuit.

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