Diaphragm, speaker, and method for manufacturing diaphragm

Abstract

To provide a diaphragm or the like that can improve productivity.SOLUTION: Since a diaphragm 110 contains thermoplastic fiber 160 and foamed particles 190, during manufacturing, a mixture of these is made into paper and shaped, and then heat-pressed to produce the diaphragm 110. Therefore, the diaphragm 110 can be manufactured by a simpler method than before, and productivity can be improved.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a diaphragm and a method for manufacturing a diaphragm. [Background technology]

[0002] For example, Patent Document 1 discloses a speaker diaphragm formed by mixing an acrylic composite resin with various fibers to create a sheet, heating it to form a foamed sheet, and then hot press molding it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-347907 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the manufacture of the above-mentioned diaphragm, since the steps of polymerization of the acrylic composite resin, foaming heat treatment, hot pressing of the sheet, etc., require a very long time, there has been a problem in that productivity is low.

[0005] Therefore, an object of the present disclosure is to provide a diaphragm or the like that can improve productivity. [Means for solving the problem]

[0006] A diaphragm according to one aspect of the present disclosure includes thermoplastic fibers and foam particles.

[0007] A speaker according to another aspect of the present disclosure includes the above-mentioned diaphragm, a voice coil body coupled to the diaphragm, and a magnetic circuit that generates a steady magnetic flux that acts on a magnetic flux that changes based on an electric signal generated by the voice coil body.

[0008] In a method for producing a diaphragm according to another embodiment of the present disclosure, thermoplastic fibers and foamed particles are mixed together, then the mixture is made into a paper sheet, and the resulting mixture is then hot-pressed. Effect of the Invention

[0009] According to the present disclosure, the productivity of diaphragms can be improved. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a speaker according to an embodiment. [Diagram 2] FIG. 2 is an enlarged image diagram illustrating components of a diaphragm according to an embodiment. [Diagram 3] FIG. 3 is a flowchart showing a flow of the manufacturing method of the diaphragm according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A diaphragm according to one aspect of the present disclosure includes thermoplastic fibers and foam particles.

[0012] According to this, since the diaphragm contains thermoplastic fibers and foam particles, the diaphragm can be manufactured by making a mixture of these into a paper and shaping it, and then performing a hot press process. Therefore, the diaphragm can be manufactured by a simpler method than before, and productivity can be improved.

[0013] In addition, since the diaphragm contains foam particles, the weight of the diaphragm can be reduced. In addition, the foam particles arranged in the gaps between the thermoplastic fibers expand when heated, thereby reducing the size of the gaps. This improves the airtightness and waterproofness of the diaphragm. In addition, the sound speed can be increased, making it possible to improve the performance of the speaker.

[0014] The diaphragm may further include reinforcing fibers.

[0015] Here, since reinforcing fibers have the properties of being lightweight and highly rigid, if the diaphragm contains reinforcing fibers, it is possible to realize a diaphragm that is both lightweight and strong.

[0016] Additionally, the diaphragm may further include fibrillated fibers.

[0017] The fibrillated fibers are fluffy fibers. This fluffing allows the foam particles to be captured more reliably, thereby preventing the foam particles from falling off the diaphragm during production.

[0018] In addition, the thermoplastic fibers may be 10% or more and 40% or less of the total weight of the diaphragm, the foamed particles may be 5% or more and 30% or less of the total weight of the diaphragm, the reinforcing fibers may be 20% or more and 60% or less of the total weight of the diaphragm, and the fibrillated fibers may be 10% or more and 30% or less of the total weight of the diaphragm.

[0019] According to this, since the thermoplastic fibers, foam particles, reinforcing fibers, and fibrillated fibers are blended so as to satisfy the above conditions, it is possible to realize a diaphragm having a good balance between weight and sound quality.

[0020] The diaphragm may further include a water- and oil-resistant agent.

[0021] According to this, since the diaphragm contains a water- and oil-resistant agent, it is possible to increase the resistance of the diaphragm to water and oil.

[0022] The diaphragm may further include a loss material.

[0023] According to this, since the diaphragm contains a loss material, the internal loss of the diaphragm can be improved.

[0024] A speaker according to another aspect of the present disclosure includes the above-mentioned diaphragm, a voice coil body coupled to the diaphragm, and a magnetic circuit that generates a steady magnetic flux that acts on a magnetic flux that changes based on an electric signal generated by the voice coil body.

[0025] According to this, since the diaphragm of the speaker contains thermoplastic fibers and foam particles, the diaphragm can be manufactured by making a mixture of these into a paper and shaping it, and then performing a hot press process. Therefore, the diaphragm can be manufactured by a simpler method than before, and productivity can be improved.

[0026] In addition, since the diaphragm contains foam particles, the weight of the diaphragm can be reduced. In addition, the foam particles arranged in the gaps between the thermoplastic fibers expand when heated, thereby reducing the size of the gaps. This improves the airtightness and waterproofness of the diaphragm. In addition, the sound speed can be increased, making it possible to improve the performance of the speaker.

[0027] In a method for producing a diaphragm according to another embodiment of the present disclosure, plastic fibers and foamed particles are mixed together, then the mixture is made into a paper sheet, and the resulting mixture is then hot-pressed.

[0028] According to this method, the diaphragm can be manufactured by making a mixture of thermoplastic fiber and foamed particles into a paper shape and then performing a hot press process. Therefore, the diaphragm can be manufactured in a simpler manner than before, and productivity can be improved.

[0029] In addition, since the diaphragm contains foam particles, the weight of the diaphragm can be reduced. In addition, the foam particles arranged in the gaps between the thermoplastic fibers expand when heated, thereby reducing the size of the gaps. This improves the airtightness and waterproofness of the diaphragm. In addition, the sound speed can be increased, making it possible to improve the performance of the speaker.

[0030] [Embodiment Mode] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that each of the embodiments described below shows a specific example of the present disclosure. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims showing the highest concept will be described as optional components.

[0031] (Speaker) First, a speaker having a diaphragm according to the present disclosure will be described. Fig. 1 is a cross-sectional view showing a speaker 100 according to an embodiment.

[0032] As shown in FIG. 1, the speaker 100 includes a diaphragm 110, a magnetic circuit 120, a base member 130, and a voice coil body 140. The diaphragm 110 is a member to which the voice coil body 140 is coupled, and is a member that generates sound by vibrating the air by displacing in the front-rear direction (Z-axis direction in the drawing) based on the vibration of the voice coil body 140 from a neutral position. In the case of this embodiment, the shape of the diaphragm 110 is a so-called cone type whose diameter gradually decreases from the front side (Z-axis positive side in the drawing) to the rear side. The outer periphery of the diaphragm 110 is coupled to the edge of the base member 130 via an edge 111 that has more flexibility and restorability than the shape of the diaphragm 110. The shape of the diaphragm 110 is not particularly limited, and examples include a cone shape, an elliptical cone shape, and a pyramid shape. It may also be a flat shape such as a disk, an elliptical plate, or a flat plate.

[0033] Magnetic circuit 120 is a component that generates a steady magnetic flux that acts on the magnetic flux that changes based on an electric signal from voice coil body 140. Magnetic circuit 120 is fixed to base member 130 so as to be located behind diaphragm 110, and includes an annular magnetic gap 121 that faces diaphragm 110. Magnetic gap 121 is an air gap that generates a steady magnetic flux in a direction that intersects with the magnetic flux generated in voice coil body 140.

[0034] The magnetic circuit 120 is an external magnet type and includes a cylindrical magnet 122 magnetized in the front-rear direction, an annular top plate 123 arranged on the surface of the magnet 122 facing the diaphragm 110, a disk-shaped base plate 124 arranged on the opposite side of the magnet 122 from the top plate 123, and a center pole 125 inserted into a through hole in the top plate 123 from the center of the base plate 124 to form a magnetic gap 121 between the base plate 124 and the top plate 123. The base plate 124 and the center pole 125 are formed integrally. The top plate 123, the base plate 124, and the center pole 125 are made of magnetic material.

[0035] The type of magnetic circuit 120 is not particularly limited, and an internal magnet type magnetic circuit 120 may be used.

[0036] Magnet 122 is a permanent magnet in the shape of a circular plate with a through hole formed in the center through which center pole 125 is inserted. One end of magnet 122 in the thickness direction (front-rear direction) is an N pole, and the other end is an S pole. A top plate 123 is fixed to a surface on one pole side of magnet 122, and a base plate 124 is fixed to a surface on the other pole side.

[0037] The base member 130 is a member called a frame or the like that serves as the structural foundation of the speaker 100, and holds the magnetic circuit 120 and the diaphragm 110 so that they are disposed at predetermined positions. The base member 130 is made of, for example, metal, resin, or the like.

[0038] The voice coil body 140 is a component whose rear end is disposed in the magnetic gap 121 of the magnetic circuit 120 and whose front end is coupled to the diaphragm 110, and which generates a magnetic flux based on an input electric signal and vibrates in the front-rear direction due to interaction with the magnetic circuit 120. The winding axis (center axis) of the voice coil body 140 is disposed in the direction of vibration (amplitude) of the diaphragm 110 (Z-axis direction in the figure) and is perpendicular to the direction of the magnetic flux in the magnetic gap 121. In the case of this embodiment, the voice coil body 140 includes a coil formed by winding a wire made of a metal such as copper in a circular (cylindrical) shape multiple times, and a bobbin around which the coil is wound. The bobbin is a cylindrical member made of a material such as aluminum or resin, and its front end is coupled to the diaphragm 110 and its rear end is disposed in the magnetic gap 121.

[0039] (diaphragm) Next, specific components of diaphragm 110 will be described. Fig. 2 is an enlarged image diagram showing the components of diaphragm 110 according to the embodiment. Fig. 2 is an enlarged diagram showing the surface of diaphragm 110. As shown in Fig. 2, diaphragm 110 includes thermoplastic fiber 160, reinforcing fiber 170, fibrillated fiber 180, and expanded particles 190.

[0040] The thermoplastic fibers 160 are, for example, fibrous bodies made of resin. The thermoplastic fibers 160 function as a binder between the reinforcing fibers 170. Examples of the resin that constitutes the thermoplastic fibers 160 include PP (polypropylene resin) and PET (polyethylene terephthalate resin). The thermoplastic fibers 160 are preferably contained in the diaphragm 110 in a range of 10% to 40% of the total weight of the diaphragm 110.

[0041] The reinforcing fibers 170 are fibers having a higher elastic modulus than the thermoplastic fibers 160. Examples of the reinforcing fibers 170 include inorganic fibers such as glass fibers, alumina fibers, and carbon fibers, and fibers derived from plants such as bamboo and hemp. The reinforcing fibers 170 are preferably contained in the diaphragm 110 in a range of 20% to 60% of the total weight of the diaphragm 110.

[0042] The fibrillated fibers 180 are fibers that are split in the axial direction and are fluffy. Examples of the fibrillated fibers 180 include thermoplastic chemical fiber fibrillated pulp, KEPAL (registered trademark), SWP (registered trademark), etc. The fibrillated fibers 180 are preferably contained in the diaphragm 110 in a range of 10% to 30% of the total weight.

[0043] The expanded particles 190 are acrylic particles that expand when heated. The expanded particles 190 expand several tens of times when heated. An example of the expanded particles 190 is expandable microspheres. The expanded particles 190 are preferably contained in the diaphragm 110 in a range of 5% to 30% of the total weight of the diaphragm 110.

[0044] In this embodiment, the content ratio of thermoplastic fibers 160 is 20% of the total weight of diaphragm 110, reinforcing fibers 170 is 40% of the total weight of diaphragm 110, fibrillated fibers 180 is 20% of the total weight of diaphragm 110, and foamed particles 190 is 20% of the total weight of diaphragm 110. In addition, it is preferable that the specific gravity of diaphragm 110 is 0.5 or less. This allows the magnetic circuit 120 and speaker 100 to be lightweight. Furthermore, it is preferable that the thickness of diaphragm 110 is 0.5 mm or less. This also allows the magnetic circuit 120 and speaker 100 to be lightweight.

[0045] (Vibration plate manufacturing method) Next, a description will be given of a method for manufacturing the diaphragm 110. Fig. 3 is a flowchart showing the flow of a method for manufacturing the diaphragm 110 according to the embodiment.

[0046] 3, in the mixing step S1, the thermoplastic fibers 160, the reinforcing fibers 170, the fibrillated fibers 180, and the expanded particles 190 are mixed in a predetermined ratio with water to prepare a mixed liquid. At this time, the mixed liquid is stirred with a mixer to mix the thermoplastic fibers 160, the reinforcing fibers 170, the fibrillated fibers 180, and the expanded particles 190 evenly.

[0047] Next, in the papermaking process S2, the mixture is filled into a papermaking mold corresponding to the shape of the diaphragm 110, and dehydrated. This forms a wet diaphragm 110. At this time, the expanded particles 190 are captured by the fluffing of the fibrillated fibers 180, so that the expanded particles 190 are prevented from falling off together with the water.

[0048] Next, in the heat pressing process S3, the wet diaphragm 110 is heated and pressurized by a heat press machine. This causes the diaphragm 110 to dry and harden. At this time, the foamed particles 190 in the diaphragm 110 expand. At this time, the foamed particles arranged in the gaps formed by the entangled fibers (thermoplastic fibers 160, reinforcing fibers 170, and fibrillated fibers 180) expand to reduce the gaps. This improves the airtightness and waterproofness of the diaphragm 110.

[0049] (Effects, etc.) As described above, according to the present disclosure, since the diaphragm 110 contains the thermoplastic fibers 160 and the foamed particles 190, during manufacturing, the mixture of these is paper-made, shaped, and then heat-pressed to manufacture the diaphragm 110. Therefore, the diaphragm 110 can be manufactured by a simpler method than before, and productivity can be improved.

[0050] Furthermore, since the diaphragm 110 contains the foamed particles 190, the weight of the diaphragm 110 can be reduced. In addition, the foamed particles 190 arranged in the gaps between the thermoplastic fibers 160 expand when heated, thereby reducing the size of the gaps. This improves the airtightness and waterproofness of the diaphragm 110, thereby increasing the speed of sound and improving the performance of the speaker 100. The speed of sound in the diaphragm is preferably 2500 m / s or higher. This allows for a wider bandwidth and allows for the output of rich sound with a large amount of information.

[0051] Furthermore, since the diaphragm 110 contains the foamed particles 190, the weight of the diaphragm 110 can be reduced. In addition, the foamed particles 190 arranged in the gaps between the thermoplastic fibers 160 expand when heated, thereby reducing the size of the gaps. This improves the airtightness and waterproofness of the diaphragm 110. Furthermore, the speed of sound can be increased, enabling the speaker 100 to have higher performance.

[0052] Here, since the reinforcing fibers 170 have the properties of being lightweight and highly rigid, if the diaphragm 110 contains the reinforcing fibers 170, it is possible to realize a diaphragm 110 that is lightweight and has high strength.

[0053] Here, the fibrillated fibers 180 are fluffy fibers. This fluffing makes it possible to more reliably capture the expanded particles 190. This makes it possible to prevent the expanded particles 190 from falling off the diaphragm 110 during production.

[0054] The thermoplastic fibers 160 account for 10% to 40% of the total weight of the diaphragm 110, the expanded particles 190 account for 5% to 30% of the total weight of the diaphragm 110, the reinforcing fibers 170 account for 20% to 60% of the total weight of the diaphragm 110, and the fibrillated fibers 180 account for 10% to 30% of the total weight of the diaphragm 110. Since the thermoplastic fibers 160, the expanded particles 190, the reinforcing fibers 170, and the fibrillated fibers 180 are blended to satisfy these conditions, it is possible to realize a diaphragm 110 with a good balance between weight and sound quality.

[0055] [others] The diaphragm 110 and the like according to the present disclosure have been described above based on the embodiment, but the present disclosure is not limited to this embodiment. As long as it does not deviate from the spirit of the present disclosure, various modifications conceived by a person skilled in the art to this embodiment and forms constructed by combining components in different embodiments may also be included within the scope of one or more aspects of the present disclosure.

[0056] The diaphragm 110 may further include a water-resistant and oil-resistant agent. If the diaphragm 110 includes a water-resistant and oil-resistant agent, it is possible to increase the resistance of the diaphragm 110 to water and oil. The resistance to chemicals such as car shampoo is also increased. Examples of the water-resistant and oil-resistant agent include fluorine-based water-resistant and oil-resistant agents.

[0057] The diaphragm 110 may further include a loss material. If the diaphragm 110 includes a loss material, it is possible to improve the internal loss of the diaphragm 110. The loss material is also called a vibration loss material or a damping material, and is a material that has the function of improving the internal loss.

[0058] In the above embodiment, the diaphragm 110 includes the thermoplastic fibers 160, the reinforcing fibers 170, the fibrillated fibers 180, and the expanded particles 190. However, it is sufficient that the diaphragm includes at least the thermoplastic fibers 160 and the expanded particles 190.

[0059] [Note] The above description of the embodiments and the like discloses the following techniques.

[0060] (Technology 1) The thermoplastic fiber includes a thermoplastic fiber and a foam particle. diaphragm.

[0061] (Technology 2) Further, the present invention includes a reinforcing fiber. The diaphragm described in technique 1.

[0062] (Technology 3) Further comprising fibrillated fibers, The diaphragm described in technique 2.

[0063] (Technology 4) The thermoplastic fibers account for 10% to 40% of the total weight of the diaphragm, The foam particles account for 5% to 30% of the total weight of the diaphragm, The reinforcing fibers account for 20% to 60% of the total weight of the diaphragm, The fibrillated fibers account for 20% to 60% of the total weight of the diaphragm. The diaphragm described in technique 3.

[0064] (Technology 5) It also contains water and oil resistant agents. The diaphragm according to any one of the first to fourth aspects.

[0065] (Technology 6) In addition, loss materials are included. The diaphragm according to any one of the first to fifth aspects.

[0066] (Technology 7) A diaphragm according to any one of techniques 1 to 7; a voice coil assembly coupled to the diaphragm; a magnetic circuit that generates a steady magnetic flux that acts on the magnetic flux that changes based on an electric signal generated by the voice coil body; Speaker.

[0067] (Technology 8) The plastic fiber and the foam particles are mixed and then molded into paper. After the molding, the molding is heat pressed. A method for manufacturing a diaphragm. [Industrial Applicability]

[0068] The present disclosure is applicable to diaphragms and the like formed by papermaking. [Explanation of symbols]

[0069] 100 Speakers 101 Gap 110 Diaphragm 111 Edge 120 Magnetic Circuit 121 Magnetic Gap 122 Magnet 123 Top Plate 124 Base Plate 125 Center Pole 130 Foundation members 140 Voice coil body 160 Thermoplastic Fibers 170 Reinforced Fiber 180 Fibrillated Fibers 190 Foam particles

Claims

1. The thermoplastic fiber includes a thermoplastic fiber and a foam particle. diaphragm.

2. Further, the present invention includes a reinforcing fiber. The diaphragm according to claim 1 .

3. Further comprising fibrillated fibers, The diaphragm according to claim 2 .

4. The thermoplastic fiber accounts for 10% to 40% of the total weight of the diaphragm, The foam particles account for 5% to 30% of the total weight of the diaphragm, The reinforcing fibers account for 20% to 60% of the total weight of the diaphragm, The fibrillated fibers account for 10% to 30% of the total weight of the diaphragm. The diaphragm according to claim 3 .

5. It also contains water and oil resistant agents. The diaphragm according to claim 4.

6. In addition, loss materials are included. The diaphragm according to claim 4 or 5.

7. A diaphragm according to any one of claims 1 to 5, a voice coil assembly coupled to the diaphragm; a magnetic circuit that generates a steady magnetic flux that acts on the magnetic flux that changes based on an electric signal generated by the voice coil body; Speaker.

8. The thermoplastic fibers and the foam particles are mixed and then molded into paper. After the molding, the molding is heat pressed. A method for manufacturing a diaphragm.

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