JP2007208906A - Method for manufacturing diaphragm for loudspeaker and diaphragm for speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a diaphragm for a loudspeaker in a multilayer structure by paper manufacturing, without applying adhesives, and to prevent failures, such as peelings between diaphragm layers, and to manufacture a diaphragm for a speaker satisfying desired conditions, where materials whose characteristics are different are layered by paper manufacturing. <P>SOLUTION: This method for manufacturing a diaphragm for the loudspeaker having a multilayer structure where a plurality of diaphragm layers are layered includes successively injecting suspension, in which the formation materials of a diaphragm layer are contained by isolating a liquid layer R52 in which the formation materials of the diaphragm layer are not contained in a common paper manufacturing tank 22, and layering a plurality of diaphragm layers by successively paper manufacturing the suspension. Thus, a diaphragm for a loudspeaker in a multilayer structure by paper manufacturing can be manufactured without applying any adhesive in comparison with a conventional manufacturing method for preliminarily paper manufacturing each diaphragm layer, and then for adhering them with an adhesive. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a speaker diaphragm and a speaker diaphragm.

  In general, a speaker device is said to have higher performance as it has higher sensitivity, a wider reproduction frequency band, and lower acoustic distortion. Therefore, it is desirable that the speaker diaphragm, which has a great influence on the above characteristics, among the main components of the speaker device, has a low material density, a high Young's modulus, and an appropriate internal loss. Further, for example, a speaker device used in a vehicle or outdoors, a speaker device used in a portable information processing device or a portable information processing device, and the like, the usage form of the speaker device is dramatically expanded, and durability and heat resistance are increased. A speaker diaphragm having high performance, water resistance, light weight, high acoustic characteristics, and the like is desired.

  However, when the speaker diaphragm is made of a single material, the above-mentioned conditions may simultaneously impose contradictory physical characteristics against the material of the speaker diaphragm, and a speaker that satisfies these conditions highly. It is difficult to form a diaphragm for use. For this reason, a diaphragm for a speaker in which materials having different characteristics are laminated so as to satisfy a desired condition is manufactured (for example, see Patent Document 1).

  By the way, as a general method for manufacturing a speaker diaphragm, for example, a method is known in which beaten wood pulp is dispersed in water, and the paper is made by a net having a desired shape and paper making. In addition, as a method for manufacturing a diaphragm having a general multi-layer structure, papers made of different forming materials are separately made, for example, a method in which an adhesive is applied and pasted by a pressure device, a paper-made semi-dried inner cone paper and A method of laminating and sandwiching a semi-dried inner-layer corn paper made between the outer-surface corn paper and heating and pressurizing is known (for example, see Patent Document 1).

JP-A-3-210897

  However, in the above-described method for manufacturing a speaker diaphragm having a multi-layer structure, different forming materials are made in advance a plurality of times, and then, for example, an adhesive is applied and then bonded by a pressure device. A pressure forming process is required. In addition, these processes require a relatively long time. Moreover, in order to perform these processes, a comparatively large-scale installation is required.

  Further, in the above-described manufacturing method, the layers made in advance are dehydrated and overlapped. For example, when the fiber layers are laminated, the bonding between the layers is relatively weak, and there is a possibility that problems such as delamination occur. When a problem such as delamination occurs, there is a problem that the acoustic characteristics of the speaker are remarkably deteriorated.

  This invention makes it an example of a subject to cope with such a problem. That is, making a diaphragm for a speaker having a multilayer structure by papermaking without applying an adhesive, preventing problems such as peeling between diaphragms, and satisfying a desired condition by stacking materials having different characteristics It is an object of the present invention to produce a diaphragm for use in papermaking.

  In order to achieve such an object, the present invention comprises at least the configurations according to the following independent claims.

  The invention according to claim 1 is a method for manufacturing a diaphragm for a speaker having a multilayer structure in which a plurality of diaphragm layers are laminated, and a liquid that does not contain a material for forming the diaphragm layer in a common papermaking tank A plurality of diaphragm layers are laminated by sequentially injecting a suspension liquid containing a material for forming the diaphragm layer through layers, and sequentially making the suspension liquid.

  The invention according to claim 10 is a loudspeaker diaphragm having a multilayer structure in which a plurality of diaphragm layers are laminated, and the diaphragm layers are separated from each other by a liquid layer not including a material for forming each diaphragm layer. A plurality of diaphragm layers are laminated by sequentially making a suspension containing a forming material, and the diaphragm layers are hydrogen-bonded.

  A speaker diaphragm manufacturing method according to an embodiment of the present invention is a speaker diaphragm manufacturing method having a multilayer structure in which a plurality of diaphragm layers are stacked. In this manufacturing method, a suspension liquid containing a diaphragm layer forming material is sequentially injected into a common papermaking tank across a liquid layer that does not include the diaphragm layer forming material. Paper is made sequentially and a plurality of diaphragm layers are stacked. At this time, the liquid layer is separated from the upper part of the papermaking tank, the diaphragm layer forming material is dispersed in the liquid and sequentially injected, and the forming material is sucked through the papermaking net provided at the lower part of the papermaking tank. Paper making.

  In the method for manufacturing the speaker diaphragm, a suspension liquid containing the diaphragm layer forming material is sequentially injected into a common papermaking tank with a liquid layer not including the diaphragm layer forming material interposed therebetween, Since the suspension liquid is sequentially made and a plurality of diaphragm layers are laminated, for example, after making each diaphragm layer in advance, compared with the conventional manufacturing method in which the adhesive layers are bonded, without applying an adhesive. Thus, a speaker diaphragm having a multilayer structure can be manufactured by papermaking.

  Also, for example, after making each diaphragm layer in advance, compared with the conventional manufacturing method in which they are pressed and bonded by a press device, a diaphragm diaphragm for a multilayer structure is produced by the above-mentioned making. The bonding force becomes relatively large, and problems such as delamination can be prevented. Moreover, in the diaphragm according to the present invention manufactured by the above manufacturing method, since the bonding force between the diaphragms is relatively large due to hydrogen bonding between the diaphragms, problems such as delamination are reduced.

  In addition, in the manufacturing method of the speaker diaphragm, which is simply made by sequentially injecting the forming material of each diaphragm layer into the papermaking tank, the forming materials are mixed in the papermaking tank. In the manufacturing method of the speaker diaphragm according to the present invention, the suspension liquid containing the formation material of each diaphragm layer is formed in the papermaking tank. Since the layers are separated by a liquid layer that does not contain the material for forming the layers, it is possible to prevent the materials for forming the diaphragm layers from being mixed with each other. A speaker diaphragm having a multilayer structure can be produced by papermaking without mixing the forming materials. Further, by sequentially stacking materials having different characteristics by papermaking, a speaker diaphragm that satisfies a desired condition can be easily manufactured.

  Hereinafter, a method for manufacturing a speaker diaphragm according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram for explaining a speaker diaphragm according to a first embodiment of the present invention. FIG. 1A is a half sectional view for explaining a speaker device employing a speaker diaphragm according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view for explaining the speaker diaphragm shown in FIG. FIG. 1C is an enlarged cross-sectional view of the speaker diaphragm shown in FIG.

  As shown in FIG. 1A, a speaker device 10 employing a speaker diaphragm according to the first embodiment of the present invention includes a magnetic circuit 1 formed by a magnet 1A, a plate 1B, and a yoke 1C, and a magnetic circuit. 1 has a voice coil 3 wound around a voice coil bobbin 2 and a speaker diaphragm 4 fixed at the center to the voice coil bobbin 2. The outer peripheral edge of the speaker diaphragm 4 is fixed to the speaker frame 7 via an edge 5 and a gasket 6. The voice coil bobbin 2 is fixed to the speaker frame 7 by a damper 8, and the opening of the voice coil bobbin 2 is covered with a center cap 9.

  The speaker diaphragm 4 has a multilayer structure in which a plurality of diaphragm layers are stacked. The speaker diaphragm 4 according to the present embodiment includes a first diaphragm layer 41 and a second diaphragm layer 42 as shown in FIGS. In this embodiment, the speaker diaphragm 4 having a two-layer structure will be described. However, the present invention is not limited to this form, and the speaker diaphragm 4 may have a multilayer structure having two or more layers.

  As a material for forming each diaphragm layer of the diaphragm 4 for the speaker, wood pulp fiber, non-wood pulp fiber, chemical fiber, synthetic fiber, animal fiber, plant fiber, organic fiber, inorganic fiber, glass fiber, carbon fiber, ceramic Various materials such as fiber materials such as fibers, powdered materials such as mica powder, graphite, carbon-based materials, metal materials, ceramic materials, and resins, and micro hollow bodies such as foamed materials in the form of hollow particles are used. can do. The forming material 411 of the first diaphragm layer 41 and the forming material 421 of the second diaphragm layer 42 may be different types of materials or the same type of materials.

  As will be described later, a suspension containing the diaphragm layer forming material is sequentially made between the diaphragm layers of the speaker diaphragm 4 with a liquid layer not including the diaphragm layer forming material interposed therebetween. A plurality of diaphragm layers are laminated, and the diaphragm layers are hydrogen-bonded. The speaker diaphragm 4 having this structure has a relatively large coupling force between the diaphragm layers, so that problems such as delamination can be prevented. Further, for example, when various fibers are used as the material for forming each diaphragm layer, the speaker diaphragm 4 having a structure laminated by papermaking entangles the fibers between the diaphragm layers, and thus the bonding force between the layers is large. In addition, problems such as delamination can be prevented.

  FIG. 2 is a view for explaining the speaker diaphragm manufacturing apparatus according to the first embodiment of the present invention. 3 is a perspective view of the manufacturing apparatus shown in FIG. The loudspeaker diaphragm manufacturing apparatus 20 according to this embodiment includes a suspension liquid containing a diaphragm layer forming material in a common papermaking tank with a liquid layer not including the diaphragm layer forming material interposed therebetween. Are sequentially injected, and the suspension is sequentially made to laminate a plurality of diaphragm layers.

  For example, as shown in FIG. 2, the manufacturing apparatus 20 according to this embodiment includes a papermaking mold 21, a papermaking tank 22, a papermaking net 23, a rectifying unit 240, a rectifying plate 24, a liquid injection unit 25, a forming material injection unit 26, It has a first forming material injection part 261, a second forming material injection part 262, a third forming material injection part 263, a pump 27, a control circuit 28, and a sensor 29. The papermaking tank 22 corresponds to an embodiment of the papermaking tank of the present invention. The papermaking net 23 corresponds to an embodiment of the papermaking net of the present invention. The rectification unit 240 corresponds to an embodiment of the rectification unit of the present invention. The rectifying plate 24 corresponds to an embodiment of the rectifying plate of the present invention.

  As shown in FIG. 2, the papermaking mold 21 is formed in a substantially cylindrical shape, and a papermaking net 23 is provided at the center of the concave portion 21A, and a suction port is provided at the bottom central portion of the concave portion 21A. 21B is formed. The papermaking tank 22 is formed in a substantially cylindrical shape, for example, and is disposed on the papermaking mold 21. In the present embodiment, a circumferential step portion 21 </ b> C formed at the upper edge of the papermaking mold 21 and a lower portion 22 </ b> A of the papermaking tank 22 are detachably fitted. A suspension liquid containing a liquid such as water or a material for forming a diaphragm is injected into the papermaking tank 22. Further, as will be described later, the papermaking tank 22 is provided with a cylinder so that a suspension containing the diaphragm layer forming material can be sequentially injected across the liquid layer not including the diaphragm layer forming material. It is preferable that the length of is formed more than a predetermined length.

  The papermaking net 23 is formed in a predetermined shape according to the shape of the speaker diaphragm, for example, and is formed in a cone shape in this embodiment. In the papermaking net 23, for example, a plurality of holes are formed in a net shape, and the forming material is deposited on the papermaking net 23 out of the suspension liquid containing the material for forming the diaphragm layer, and the liquid passes through the holes. Let As the papermaking net 23, for example, a metal net or punching metal can be employed.

  The rectification unit 240 is provided in the upper part of the papermaking tank 22 and injects liquid into the papermaking tank 22 from the upper part of the papermaking tank 22 in a vortex. Specifically, the rectifying unit 240 injects a forming material and a liquid to form a liquid vortex in the upper part of the liquid layer that does not include the forming material of the diaphragm layer in the papermaking tank 22. Has the function of dispersing in.

  The rectifying unit 240 according to the present embodiment includes a rectifying plate 24 as shown in FIGS. The rectifying plate 24 is provided below the inner peripheral upper end 22B of the papermaking tank 22 by a specified distance 22C. 2 and 3, the rectifying plate 24 includes a central opening 241 having an opening diameter 241A formed in the central portion of the rectifying plate 24, and between the opening 242 and the outer peripheral end 24A of the rectifying plate 24. The material injection opening 242 for injecting the material for forming the diaphragm layer is formed.

  In the rectifying unit 240 configured as described above, for example, when a liquid such as water is injected from the liquid injection unit 25 along the circumferential direction from the outer peripheral end 24A of the rectifying plate 24, a liquid vortex is formed on the rectifying plate 24. Thus, the vortex liquid can be injected into the papermaking tank 22 from the central opening 241. Further, the material for forming the diaphragm layer can be injected into the papermaking tank 22 from the material injection opening 242. More specifically, when a vibrating plate forming material or a suspension liquid containing the forming material is introduced into the liquid forming the vortex on the rectifying plate 24, the forming material moves on the rectifying plate 24 along the flow of the liquid. While rotating, it is injected into the papermaking tank 22 from the material injection opening 242. The forming material is injected into the papermaking tank 22 from the central opening 241 along the flow of the liquid.

  In the rectifying unit 240 having the above-described configuration, the diaphragm forming material is injected into the papermaking tank 22 from the material injection opening 242 and the central opening 241, so that the forming material is easily dispersed in the liquid in the papermaking tank 22. Can be made.

  The liquid injection unit 25 injects a liquid such as water, which is a solvent of the vibration plate forming material, into the papermaking tank 22. For example, as illustrated in FIG. 2, the liquid outlet 25 </ b> A of the liquid injection unit 25 is provided above the rectifying plate 24 of the rectifying unit 240. For example, the liquid injection unit 25 injects liquid along the circumferential direction from the outer peripheral end 24 </ b> A of the rectifying plate 24 to form a liquid vortex on the rectifying plate 24.

  The forming material injection unit 26 injects a forming material of the diaphragm. For example, as shown in FIG. 2, the injection outlet of the forming material injection unit 26 is disposed above the rectifying plate 24 of the rectifying unit 240. In addition, the forming material injecting unit 26 injects, for example, the forming material of the diaphragm directly or a suspension liquid containing the forming material in a liquid. In addition, the forming material injection unit 26 includes a plurality of forming material injection units, in the present embodiment, a first forming material injection unit 261, a second forming material injection unit 262, and a first forming material injection unit, for injecting the forming material of each diaphragm layer. 3 forming material injection portion 263. The first forming material injection unit 261 injects a forming material for forming the first diaphragm layer. For example, the first forming material injection part 261 may be disposed above the central opening 241 of the rectifying plate 24 or may be disposed above the rectifying plate 24 other than that. When forming the first diaphragm layer, in order to simplify the operation, when the suspension containing the first diaphragm layer forming material is directly injected into the papermaking tank 22, the first forming material injection section It is preferable to arrange 261 above the central opening 241. The second forming material injection unit 262 and the third forming material injection unit 263 inject the forming material of the second diaphragm layer or other diaphragm layers.

  The pump 27 is composed of a suction pump, for example, and is disposed in the suction port 21 </ b> B of the papermaking mold 21. The pump 27 sucks liquid or the like through a papermaking net 23 provided at the lower part of the papermaking tank 22.

  The control circuit 28 comprehensively controls the entire manufacturing apparatus 20 to realize the function according to the present invention. For example, the control circuit 28 controls driving of, for example, the liquid injection unit 25, the formation material injection unit 26, the first formation material injection unit 261, the second formation material injection unit 262, the third formation material injection unit 263, and the pump 27. To do. At this time, the control circuit 28 performs the above control based on the detection result of the sensor 29 provided in the papermaking tank 22, as shown in FIG. The sensor 29 detects characteristics relating to the liquid and the forming material in the papermaking tank 22 such as the liquid level, the degree of dispersion of the forming material in the liquid, the degree of the vortex flow of the liquid, and the like, and a signal indicating the detection result. Output to the control circuit 28.

  Next, a method for manufacturing the speaker diaphragm according to the first embodiment of the present invention using the manufacturing apparatus 20 will be described with reference to the drawings. In this embodiment, water is used as the liquid used for papermaking.

[First diaphragm layer forming step]
First, as shown in FIG. 2, a suspension containing the forming material 411 of the first diaphragm layer 41 is injected into the papermaking tank 22. At this time, the forming material 411 may be directly injected from the first forming material injection unit 261 into the papermaking tank 22 while injecting a liquid such as water 251 from the liquid injection unit 25 into the papermaking tank 22 or may be prepared in advance. The suspension containing the formed forming material 411 may be injected into the papermaking tank 22 from the first forming material injection unit 261. In the papermaking tank 22, as shown in FIG. 2, a suspension liquid layer R51 in which the forming material 411 is dispersed in water is formed. In the regular shape paper mesh 23, the liquid passes through the mesh, and the forming material 411 is deposited on the paper mesh 23. At this time, the liquid may be forcibly sucked by the pump 27, or the forming material 411 may be naturally deposited on the papermaking net 23 without the forced suction.

[Liquid layer injection process]
FIG. 4 is a view for explaining a liquid layer injection step of the method for manufacturing the speaker diaphragm according to the first embodiment of the present invention.

  After injecting the forming material 411 of the first diaphragm layer 41 into the papermaking tank 22, the liquid injection unit 25 injects a predetermined amount of water 251 as shown in FIG. In the papermaking tank 22, as shown in FIG. 4, a liquid layer R <b> 52 that does not contain a diaphragm layer forming material is formed. The thickness of the liquid layer R52 (the length along the vertical direction of the papermaking tank 22) can be determined according to various conditions such as the specific gravity of the material forming each diaphragm layer, the falling speed in the liquid, and the like. preferable.

[Second diaphragm layer forming step]
FIG. 5 is a view for explaining a second diaphragm layer forming step of the method for manufacturing the speaker diaphragm according to the first embodiment of the present invention. FIG. 6 is a top view of the speaker diaphragm manufacturing apparatus 20. FIG. 7 is a diagram for explaining a process of dispersing the forming material in the liquid. FIG. 8 is a view for explaining the state of deposition after the injection of the suspension containing the material for forming the second diaphragm layer.

  Next, as shown in FIGS. 5 to 8, the forming material 421 of the second diaphragm layer 42 is injected from the second forming material injection portion 262. At this time, as shown in FIGS. 5 to 8, for example, water 251 is injected from the liquid injection unit 25 along the circumferential direction from the outer peripheral end 24 </ b> A of the rectifying plate 24, and the vortex of the water 251 is generated on the rectifying plate 24. When the suspension liquid is formed and the suspension liquid containing the forming material 421 is injected from the second forming material injection portion 262, the forming material 421 rotates on the current plate 24 along the flow of the water 251 and the material injection opening portion 242 is rotated. The remaining forming material 421 is injected into the papermaking tank 22 from the central opening 241 along the flow of the liquid 251.

  In the papermaking tank 22, as shown in FIGS. 5 and 7, a suspension liquid layer R 53 including the forming material 421 for the second diaphragm layer 42 is formed on the upper side of the liquid layer R 52. Further, since the water 251 and the suspension liquid are injected in a vortex form from the rectifying unit 240, a vortex is formed at a shallow position (upper part) in the papermaking tank 22, and the material for forming the diaphragm layer is substantially uniform in the water 251. scatter. That is, as shown in FIG. 7, in the papermaking tank 22, the suspension liquid layer R51 containing the forming material 411 of the first diaphragm layer 41 and the forming material 421 of the second diaphragm layer 42 were included. Between the suspension liquid layer R53, a liquid layer R52 that does not include a diaphragm forming material is formed. Then, as shown in FIG. 8, the paper is sequentially made by the paper making net 23 in this state. At this time, the forming material may be sucked by the pump 27 through the papermaking net 23 to perform forced dehydration, or papermaking may be performed by natural fall. The strength of suction of the pump 27 is appropriately set according to the amount of water supplied from the liquid injection unit 25 and the like.

  As shown in FIG. 8, after injecting the forming material 421, a prescribed amount of water 251 may be injected from the liquid injecting unit 25 to form the liquid layer R <b> 54 that does not include the forming material of the diaphragm layer. The liquid injection unit 25 appropriately injects the water 251 in accordance with the state of the suspension liquid layer R53, the state of lamination on the papermaking net 23, and the like, and suppresses the injection of the water 251 at a predetermined timing.

[Molding process]
FIG. 9 is a diagram for explaining a molding process of the speaker diaphragm according to the first embodiment of the present invention. After the paper making, the first diaphragm layer 41 and the second diaphragm layer 42 laminated on the paper making net 23 are formed by a forming method such as a hot press method, a wet press method, an oven method, etc. The speaker diaphragm 4 is produced as shown in FIGS. The first diaphragm layer 41 and the second diaphragm layer 42 laminated on the papermaking net 23 are taken out, and for example, as shown in FIG. 9, a female die 61 provided with a heating unit 611 and a heating unit 621 are provided. The speaker diaphragm 4 having a predetermined shape is manufactured by heating and pressurizing with a mold 60 having a male mold 62.

Next, a specific example of a method for manufacturing a speaker diaphragm having a two-layer structure will be described.
As the forming material 411 of the base material layer (first diaphragm layer 41), wood pulp fiber NBKP (softwood bleached kraft pulp) is employed. First, the NBKP of this wood pulp fiber is beaten and set to a beating degree of about 20 ° SR (Shopper Ligler) and dispersed in water to prepare a suspension having a concentration of about 1.0 g / L. As shown in FIG. 2, the suspension is injected from the first forming material injection unit 261 into the papermaking tank 22. The forming material 411 starts to settle due to the weight of the fiber after the injection, and then is deposited on the paper mesh 23 having a predetermined shape when sucked by the pump 27 from the suction port 21B through the paper mesh 23. At this time, water 251 is continuously injected from the rectifying plate 24 at a rate of about 5 L (liter) per minute, and as shown in FIGS. 4, 5, and 7, the liquid does not contain the material for forming the diaphragm layer. Layer R52 is formed.

Next, NBKP (coniferous tree bleached kraft pulp) is adopted as the surface layer (second diaphragm layer 42) forming material 421, and a NBKP raw material adjusted to a beating degree of about 20 ° SR is dispersed in water to obtain a concentration of 1. It is adjusted to about 0 g / L, similarly injected from the rectifying plate 24, sucked through the papermaking net 23 by the pump 27, and deposited on the papermaking net 23. In this case, the strength of the suction needs to be balanced with the amount of water supplied. The pump 27 according to the present embodiment can be adjusted to a vacuum pressure of about 0 to 500 mmHg (0 to 66660 Pa). Then stop water injection. Next, the papermaking tank 22 is removed, and the papermaking net 23 is placed on the mold 60 having the same shape and sucked to move the deposited material onto the mold 60 as shown in FIG. At this time, the mold 60 is heated to a temperature of about 160 ° C. and dried by pressing at a pressure of about 2 kg / cm ² (196 kPa) for about 40 seconds. In the example described above, the first diaphragm layer 41 and the second diaphragm layer 42 may be dyed in different colors.

The physical properties of the speaker diaphragm 4 produced in the above embodiment were measured. The density ρ is 0.633 g / cm ³ (633 kg / m ³ ), the Young's modulus E is 3.93 × 10 ⁹ N / m ² , the internal loss is 5.00 × 10 ⁻² , and the propagation velocity (E / ρ) ^0.5 was 2.49 × 10 ³ m / sec.

For comparison, physical properties were also measured on a conventional paper-making diaphragm, and the density ρ was 0.592 g / cm ³ (592 kg / m ³ ), and the Young's modulus E was 3.89 × 10 ⁹ N / m ² , internal loss was 4.85 × 10 ⁻² , and propagation velocity (E / ρ) ^0.5 was 2.57 × 10 ³ m / sec.

  As described above, the density was higher than the conventional value, the Young's modulus was higher, the internal loss was higher, and the propagation speed was slightly lower.

  As described above, in the present embodiment, the suspension liquid containing the diaphragm layer forming material is sequentially separated in the common papermaking tank 22 by separating the liquid layer R52 not including the diaphragm layer forming material. Injecting and sequentially making the suspension liquid and laminating a plurality of diaphragm layers, for example, after making each diaphragm layer in advance, apply the adhesive compared to the conventional manufacturing method of bonding with adhesive Therefore, a speaker diaphragm having a multilayer structure can be manufactured by papermaking.

  Further, since the speaker diaphragm having a multilayer structure is manufactured by the above papermaking, the coupling force between the diaphragm layers becomes relatively large, and problems such as delamination can be prevented. Moreover, in the diaphragm according to the present invention manufactured by the above manufacturing method, since the bonding force between the diaphragms is relatively large due to hydrogen bonding between the diaphragms, problems such as delamination are reduced. In addition, a diaphragm having a multilayer structure having desired physical properties and acoustic characteristics can be obtained by appropriately selecting a material for forming the diaphragm layer. Further, while maintaining the physical characteristics of the diaphragm made by papermaking, an appropriate internal loss can be obtained, and a novel appearance can be produced.

[Second Embodiment]
FIG. 10 is a diagram for explaining a method of manufacturing the speaker diaphragm 4b according to the second embodiment of the present invention. A description of the same configuration, operation, and the like as in the first embodiment will be omitted.

  In the manufacturing method of the speaker diaphragm 4b according to the present embodiment, the speaker diaphragm 4b is manufactured by paper making and then molding by an oven method. Specifically, for example, as shown in FIG. 10, the first diaphragm layer 41 b and the second diaphragm layer 42 laminated by the paper making are placed in a mold 63 having a hollow portion 631 in a drying pot 600. Then, it is dried by a heating device 64 such as a gas stove disposed above the mold 63 while being sucked by the vacuum pump 632. In this embodiment, the speaker diaphragm 4b is produced only by drying without applying pressure.

  Next, a specific method for manufacturing the speaker diaphragm 4b will be described. First, as in the first embodiment, two kinds of raw materials of 20 ° SR of NBKP of different colors dyed in a desired color tone are deposited on the papermaking net 23 and transferred to a drying mold 63, It puts in the drying pot 600 by which the heating apparatus 64 provided with a gas stove and a shielding board is arrange | positioned upwards. From the lower side of the mold 63, suction is performed with a vacuum pressure of about 500 mmHg (66660 Pa) to 600 mmHg (79992 Pa), and drying is performed with hot air from the heating device 64. In this step, the speaker diaphragm 4b can be produced without applying pressure by a so-called oven method in which the deposited material is dried without pressing.

The physical properties of the speaker diaphragm 4b produced in the above embodiment were measured. Density ρ is 0.434 g / cm ³ (434 kg / m ³ ), Young's modulus E is 1.22 × 10 ⁹ N / m ² , internal loss is 6.61 × 10 ⁻² , and propagation velocity (E / ρ) ^0.5 was 1.68 × 10 ³ m / sec.

  As described above, in the method for manufacturing the speaker diaphragm 4b according to the present embodiment, the speaker diaphragm 4b with low density and high internal loss can be manufactured. Further, the speaker diaphragm 4b obtained by the above manufacturing method is a laminate of oven cones, and even if the two layers of the first diaphragm layer 41b and the second diaphragm layer 42b are peeled off, the fibers of each other Since the adhesive strength between the layers is so great that they are destroyed at the same time, delamination can be prevented.

[Third Embodiment]
FIG. 11 is a diagram for explaining a speaker diaphragm 4c according to a third embodiment of the present invention. FIG. 11A is a cross-sectional view for explaining the speaker diaphragm 4c, and FIG. 11B is an enlarged cross-sectional view of the speaker diaphragm 4c shown in FIG. The description of the same configuration and operation as those in the first and second embodiments is omitted. As shown in FIG. 11, the speaker diaphragm 4c according to the present embodiment has a three-layer structure of a first diaphragm layer 41c, a second diaphragm layer 42c, and a third diaphragm layer 43c. A foam layer is formed in the intermediate layer of the second diaphragm layer 42c. This foamed layer is produced by making a fine hollow body (a foamed material 422 having a hollow particle shape) that expands by heating, and then compressing it by heating.

  FIG. 12 is a diagram for explaining a method of manufacturing the speaker diaphragm 4c according to the third embodiment of the present invention. A method of manufacturing the speaker diaphragm 4c having the above configuration will be briefly described. In the present embodiment, in the papermaking tank 22, after injecting a suspension containing the material for forming the first diaphragm layer 41, a liquid layer R 52 is formed, and a micro hollow body having a property of expanding by heating (hollow) A particulate foam material 422) is injected. Thereafter, as shown in FIG. 12, a liquid layer R53 that does not contain the diaphragm forming material is formed, and the suspension liquid that contains the third diaphragm forming layer 431 (432) forming material from the third forming material injecting portion 263. Is injected into the papermaking tank 22 to form a suspended layer R55. When the pump 27 sucks the paper through the papermaking net 23, the first diaphragm layer 41c, the second diaphragm layer 42c, and the third diaphragm layer 43c are stacked on the papermaking net 23. As shown in FIG. 9, the first diaphragm layer 41c, the second diaphragm layer 42c, and the third diaphragm layer 43c of this laminated structure are heated and pressurized by a mold 60 as in the first embodiment. Thus, a speaker diaphragm 4c having a three-layer structure as shown in FIG. 11 is produced.

  A specific manufacturing method will be described below. As a material for forming the base material layer (first diaphragm layer 41c), a pulp fiber prepared to NBKP 20 ° SR is used as in the first embodiment, and the pulverized size is used to further increase the waterproof property of the pulp material. Add about 5% of the agent. As a material for forming the intermediate layer (second diaphragm layer 42c), for example, a fine hollow body having an average particle diameter of about 20 μm and a property of expanding by heating is dispersed in water to a concentration of about 1.0 g / L. Is made. After injecting water 251 into this turbid liquid in the same manner as in the first embodiment, the pulp raw material 431 (the same as the base material layer (first diaphragm layer 41c) as the material for forming the surface layer (third diaphragm layer 43c) ( 90%), a mixture of mica powder 432 at a rate of 10% is prepared to a concentration of about 1.0 g / L, and a sizing agent is similarly added to about 5% to prepare a turbid liquid. After the liquid is poured into the papermaking tank 22, the first diaphragm layer 41c, the second diaphragm layer 42c, and the third diaphragm layer 43c are sucked from the suction port through the papermaking net 23 and deposited on the papermaking net 23. Is press-dried by a mold 60 heated to about 160 ° C. as in the first embodiment. When heated, the minute hollow body expands and a foam layer is formed on the second diaphragm layer 42c as shown in FIG. 11 (b).

The physical properties of the speaker diaphragm 4c produced in the above embodiment were measured. The density ρ is 0.516 g / cm ³ (516 kg / m ³ ), the Young's modulus E is 2.24 × 10 ⁹ N / m ² , the internal loss is 5.17 × 10 ⁻² , and the propagation velocity (E / ρ) ^0.5 was 2.08 × 10 ³ m / sec.

  As described above, in the present embodiment, as the material for forming the second diaphragm layer 42c, unfoamed particles (micro hollow bodies) that are foamed by heating are employed. By pressurizing and heating, the speaker diaphragm 4c having a three-layer structure including a foam layer in the intermediate layer can be easily manufactured. That is, the low-density speaker diaphragm 4c can be manufactured by the above manufacturing method. Since the foamed particles of the material forming the intermediate layer (second diaphragm layer 42c) of the speaker diaphragm 4c have heat-fusibility, the foamed particles are heated to form an intermediate layer (second diaphragm) having no air permeability. Layer 42c) can be formed. By reducing the air permeability, it is possible to prevent water droplets from entering the diaphragm surface.

  In the present invention, the most hydrogen bond that dries the wood pulp fiber is used. However, when the wood pulp fiber comes into contact with water droplets, the bonding strength is weakened. Therefore, it is usually impregnated with acrylic lacquer or the like to impart moisture resistance, but by having a layer that does not have air permeability in the intermediate layer, it prevents ingress of water droplets in combination with a sizing agent, etc. A decrease can be prevented. The air permeability of the diaphragm according to the present invention was not confirmed even in the air permeability test by JISP8117. Further, the speaker diaphragm 4c can obtain surface gloss and a novel appearance by adding mica to the surface layer (third diaphragm layer 43c).

  The present invention is not limited to the embodiment described above. You may combine embodiment and the specific example which were mentioned above. Moreover, the forming material of each diaphragm layer mentioned above is not restricted to embodiment mentioned above.

  As described above, this is a method for manufacturing a speaker diaphragm having a multilayer structure in which a plurality of diaphragm layers are laminated. In this manufacturing method, for example, as shown in FIG. The liquid layer R52 that does not contain the plate layer forming material is separated from the liquid layer R52, and the suspension liquid containing the vibration plate layer forming material is sequentially injected, and the suspension liquid is sequentially made to stack a plurality of vibration plate layers. Therefore, for example, after making each diaphragm layer in advance, it is possible to produce a diaphragm for a speaker having a multilayer structure by making paper without applying an adhesive as compared with a conventional manufacturing method in which each diaphragm layer is bonded with an adhesive.

  Also, for example, after making each diaphragm layer in advance, compared with the conventional manufacturing method in which they are pressed and bonded by a press device, a diaphragm diaphragm for a multilayer structure is produced by the above-mentioned making. The bonding force becomes relatively large, and problems such as delamination can be prevented. Moreover, in the diaphragm according to the present invention manufactured by the above manufacturing method, since the bonding force between the diaphragms is relatively large due to hydrogen bonding between the diaphragms, problems such as delamination are reduced.

  Further, in the manufacturing method of the speaker diaphragm in which the forming material of each diaphragm layer is simply injected into the papermaking tank 22 and the papermaking is performed, these forming materials are mixed in the papermaking tank 22 and papermaking is performed in the mixed state. However, in the method for manufacturing a speaker diaphragm according to the present invention, a suspension liquid containing the formation material of each diaphragm layer is formed in the papermaking tank 22. Since the diaphragm layers are separated by the liquid layer R52 that does not include the diaphragm layer forming material, it is possible to prevent the diaphragm layer forming materials from being mixed with each other. A diaphragm for a loudspeaker having a multilayer structure can be manufactured by papermaking without mixing the material for forming the diaphragm layer.

  Further, by sequentially stacking materials having different characteristics by papermaking, a speaker diaphragm that satisfies a desired condition can be easily manufactured.

  In the method for manufacturing a speaker diaphragm according to the present invention, the specific effects described later can be obtained.

  1. According to the present invention, when producing and manufacturing fiber materials such as wood pulp fibers, chemical fibers, and inorganic fibers, powders such as mica powder, graphite, amorphous carbon, and micro hollow bodies, etc. It is possible to easily manufacture a speaker diaphragm having a multilayer structure in which a plurality of layers are stacked.

  2. According to the present invention, when the material for forming each layer is laminated, the material layer of each layer is injected into the same papermaking tank 22 with the liquid layer R52 interposed therebetween, and this is sucked to make the paper, so that the diaphragm for a speaker can be easily used. Can be produced.

  3. According to the present invention, the adhesion between the layers does not require an adhesive or the like, and utilizes a bonding force based on hydrogen bonding between fibers such as wood pulp. Even in a multilayer structure, the weight increases. Can be prevented.

  4). According to the present invention, in a diaphragm made by papermaking, a diaphragm having a two-layer, three-layer, and multi-layer structure can be formed by a simple process. The plate 4 can be produced.

  5. According to the present invention, since sufficient water is present when the pulp fibers are dried in bonding between the respective layers that form the laminated structure, the fiber-to-fiber bond can have a strong structure. For example, in a manufacturing method in which bonding is performed by press molding, a papermaking base material having a low density called an oven type cannot be produced. However, in the present invention, an oven type low-density multilayer structure can be produced.

  6). According to the present invention, it is possible to freely set a desired strength by selecting a material as necessary at the time of design, such as a hard surface layer and a soft inside.

  7). According to the present invention, it is possible to obtain a multilayer structure without air permeability by inserting a fusion fiber or the like into the intermediate layer and fusing it.

  8). According to the present invention, in order to laminate the liquid layers with each other, strictly speaking, since the materials forming the layers are partially mixed, the bonding force between the layers is strong, and problems such as delamination can be reduced. it can.

  9. According to the present invention, even if the specific gravity of the forming material of each diaphragm layer is different, the turbid layer containing each forming material is sequentially made by separating the liquid layer, so that the forming material of each layer is not complicated. A speaker diaphragm having a structure can be manufactured.

It is a figure for demonstrating the diaphragm for speakers concerning 1st Embodiment of this invention. (A) is a half sectional view for explaining a speaker device employing the speaker diaphragm according to the first embodiment of the present invention. (B) is sectional drawing for demonstrating the speaker diaphragm shown to (a). (C) is a cross-sectional enlarged view of the speaker diaphragm shown in (b). It is a figure for demonstrating the manufacturing apparatus of the diaphragm for speakers which concerns on 1st Embodiment of this invention. It is a perspective view of the manufacturing apparatus shown in FIG. It is a figure for demonstrating the liquid layer injection | pouring process of the manufacturing method of the diaphragm for speakers which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the 2nd diaphragm layer formation process of the manufacturing method of the diaphragm for speakers which concerns on 1st Embodiment of this invention. It is a top view of the manufacturing apparatus 20 of the diaphragm for speakers. It is a figure for demonstrating the process of disperse | distributing a forming material in a liquid. It is a figure for demonstrating a mode that it accumulates after injection | pouring of the suspension liquid containing the formation material of a 2nd diaphragm layer. It is a figure for demonstrating the shaping | molding process of the diaphragm for speakers which concerns on 1st Embodiment of this invention. It is a figure for demonstrating the manufacturing method of the diaphragm 4b for speakers which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the diaphragm 4c for speakers which concerns on 3rd Embodiment of this invention. (A) is sectional drawing for demonstrating the diaphragm 4c for speakers, (b) is a cross-sectional enlarged view of the diaphragm 4c for speakers shown to (a). It is a figure for demonstrating the manufacturing method of the diaphragm 4c for speakers which concerns on 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic circuit 1A Magnet 1B Plate 1C Yoke 2 Voice coil bobbin 3 Voice coil 4 Speaker diaphragm 5 Edge 6 Gasket 7 Speaker frame 8 Damper 9 Center cap 10 Speaker apparatus 20 Manufacturing apparatus 21 Papermaking mold 22 Papermaking tank 23 Papermaking network 24 Rectification Plate 25 Liquid injection portion 26 Forming material injection portion 27 Pump 28 Control circuit 41, 41b, 41c First diaphragm layer 42, 42b, 42c Second diaphragm layer 43c Third diaphragm layer 240 Rectifier 261 First forming material injection Part 262 second forming material injection part 263 third forming material injection part R52 liquid layer (water layer not including diaphragm forming material)

Claims (10)

A method for manufacturing a speaker diaphragm having a multilayer structure in which a plurality of diaphragm layers are laminated,
Into a common papermaking tank, a suspension containing the diaphragm layer forming material is sequentially injected across a liquid layer that does not contain the diaphragm layer forming material, and the suspension is sequentially made. A method for manufacturing a speaker diaphragm, comprising laminating the plurality of diaphragm layers.   From the upper part of the papermaking tank, the forming material of the diaphragm layer is dispersed in the liquid, sequentially injected across the liquid layer, and the forming material is sucked through the papermaking net provided at the lower part of the papermaking tank. The method for manufacturing a speaker diaphragm according to claim 1, wherein the paper making is performed. The papermaking tank has a rectifying unit that injects liquid into the papermaking tank in a vortex from the top of the papermaking tank,
The forming material and the liquid are injected from the rectifying unit, and a liquid vortex is formed on the liquid layer not including the forming material of the diaphragm layer in the papermaking tank, and the forming material is used as the liquid. The method for manufacturing a speaker diaphragm according to claim 2, wherein the speaker diaphragm is dispersed therein. The rectifying unit has a rectifying plate having an opening formed in a central part,
4. The method for manufacturing a speaker diaphragm according to claim 3, wherein a liquid vortex is formed on the rectifying plate, and the vortex liquid is injected into the papermaking tank from the opening. In the current plate, an opening for injecting the forming material is formed between the opening and the outer peripheral end,
5. The method for manufacturing a speaker diaphragm according to claim 4, wherein the forming material is injected into the papermaking tank from at least an opening for injecting the forming material.   6. The material for forming the diaphragm layer having a different specific gravity is sequentially made and laminated with a liquid layer not including the material for forming the diaphragm layer being separated. A manufacturing method of the diaphragm for speakers described in 1.   The material for forming the diaphragm layer includes any of wood pulp fibers, non-wood pulp fibers, chemical fibers, inorganic fibers, mica powder, graphite, carbon-based materials, metal materials, ceramic materials, and hollow particle foam materials. The manufacturing method of the diaphragm for speakers as described in any one of Claims 1-6 characterized by the above-mentioned.   The speaker diaphragm manufacturing method according to any one of claims 1 to 7, wherein after the paper making, the speaker diaphragm is molded by any one of a hot press method, a wet press method, and an oven method. The material for forming the diaphragm layer includes a foamed material having a hollow particle shape,
7. The diaphragm layer including a foamed layer is formed by heating and pressurizing the sheet speaker diaphragm in a mold after the sheet making. A manufacturing method of the diaphragm for speakers described in 1. A speaker diaphragm having a multilayer structure in which a plurality of diaphragm layers are laminated,
A plurality of diaphragm layers are laminated by sequentially forming a suspension containing the diaphragm layer forming material across a liquid layer not including the diaphragm layer forming material, and the diaphragm layers are stacked. A speaker diaphragm characterized by being hydrogen-bonded.

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