JPH0321115Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to an improvement of a dome speaker vibration system, and relates to a speaker having a vibration system integrally made of a material that has high rigidity and is extremely easy to mold. Taking a dome-shaped speaker as an example, a general speaker includes a diaphragm 11, a voice coil 12 bonded to the bottom surface of the diaphragm 11, as shown in FIG.
A vibration system consisting of an edge part 13 that is bonded to the outer periphery of the diaphragm 11 and supports the diaphragm is sandwiched between the outer periphery of the edge part 13 by fixing rings 14 and 14', and a frame 15 or a magnetic circuit plate 16. It has a structure in which it is fixed by screws etc. The parts that make up these vibration systems, such as the diaphragm, edge part, fixing ring, and voice coil, are each manufactured separately, and are usually assembled into the speaker by gluing or other means during the preliminary processing process. However, this requires costs for preliminary processing,
Moreover, the assembly accuracy was also poor. To solve this problem, there is a speaker vibration system in which the above-mentioned parts constituting the vibration system are integrally molded from plastic. Because it is not possible to use a good heat-softening synthetic resin and to mix enough filler to improve the fluidity of the resin, the Young's modulus and specific strength of the diaphragm part are low and the rigidity is insufficient. The drawback was that good frequency characteristics could not be obtained because the piston vibration band was narrow. This idea uses a composite material obtained by mixing montmorillonite with a curing agent or curing accelerator adsorbed between the layers, a thermosetting resin monomer, carbon short fibers or silicon carbide whiskers, and heating and curing the mixture.
As shown in FIG. 2, a vibration system includes a diaphragm 1, an edge portion 2, a fixing ring or frame 4 for fixing the outer periphery of the edge portion 2 to a magnetic circuit, a voice coil portion 3, and a terminal portion 5. This is a speaker with a To explain in detail the composite material for molding used in the speaker vibration system of the present invention using an example using a dome diaphragm, montmorillonite, which adsorbs a hardening agent or hardening accelerator, is a type of hydrated silicate mineral.
It has the composition Al ₂ O ₃ 4SiO ₂・nH ₂ O, and is also called bentonite. ^Na
It has a three-layer structure with an ionic layer consisting of interlayer ions such as Ca ⁺ , and due to the presence of the interlayer ions, other ions and water can be adsorbed between the silicate layers, and the adsorbed substances can be removed by heating. It has the function of emitting light. In the embodiment of the present invention, the montmorillonite is immersed (60°C, several hours) in a solution of a hardening agent (diaminodiphenylmethane) dissolved in an appropriate solvent.
Next, it is washed with a solvent and then dried to obtain a composite in which a curing agent is adsorbed between the silicate layers. Next, 6 parts of the above composite, 29 parts of thermosetting resin (epoxy resin) monomer, 4.2 parts of curing agent (diaminodiphenylsulfone), 1 part of mold release agent (zinc stearate), short carbon fibers (average length 0.35mm) 60
The mixture is stirred under heat (85°C) to mix uniformly, cooled, and then ground to obtain a powdered mixture for molding. The above mixture is pressed in a mold of a predetermined shape (by setting the voice coil wire 31 and terminal fitting 51 in the mold predetermined position as necessary) at a temperature of 160°C, a pressing pressure of 50 kg/cm ² , and a molding time of 10 minutes. Molded. In the above composite material, the epoxy resin melts in the press mold once during molding, becomes low viscosity, and flows, but the curing agent adsorbed between the montmorillonite layers does not ooze out until a certain temperature (150°C), so the epoxy resin has low viscosity and fluidity. As a result, even if the mold has a complex shape, even thin parts such as the dome part 1 and the edge part 2, it is filled to every corner, and after that, when the mold temperature reaches the molding temperature, The curing agent adsorbed on the montmorillonite leaches out and hardens the epoxy resin. At this time, since it is cured with the flow flowing into every corner of the mold, it is possible to obtain a vibration system with extremely precise shape and dimensions. By integrally molding the ring part or the frame 4, the mutual positional relationship of these parts becomes highly accurate, so the trouble of adjusting the mutual positional relationship between the vibration system, magnetic circuit, and frame is eliminated when assembling the speaker. It is possible to do so. Further, by inserting the voice coil wire 31 and the terminal fitting 51 during molding, further labor savings can be achieved. Furthermore, since the main materials are a thermosetting resin and an inorganic filler, it is possible to obtain a product that is extremely stable against external conditions such as temperature and humidity. In this embodiment, a dome-shaped diaphragm is used as an example, but a flat plate type or other shapes can be molded in the same manner. Next, the physical properties (Young's modulus E, density P, specific strength E/
P) is shown in Table 1 in comparison with the conventional example. The conventional example compared is polypropylene resin.
This is a diaphragm made by injection molding a mixture of 15wt% carbon fiber.

[Table] Next
example
As is clear from this table, the diaphragm portion E/p of the vibration system according to the present invention is extremely high, and the divided vibration frequency of the diaphragm becomes high, expanding the reproduction band of the speaker and widening the frequency characteristics. It is possible to achieve good results over a period of time. The reason for the remarkable increase in E/p of the composite material of the present invention is that a blended polymer is formed in which the epoxy polymer and montmorillonite are firmly bonded between the layers of montmorillonite, and the blended polymer is carbonaceous. This is thought to be because the particles are organized into a three-dimensional network structure that entangles the particles. The same effect can be obtained by using high-rigidity fibers such as silicon carbide whiskers instead of the above-mentioned carbon fibers as the composite material of the present invention. As described above, the present invention is a composite material made by mixing montmorillonite with a hardening agent or hardening accelerator adsorbed between its layers, a thermosetting resin monomer, and high-rigidity fibers such as carbon fiber or silicon carbide whiskers, and heating and hardening the mixture to generate vibrations in a speaker. This is a speaker with a vibration system in which the plate part, edge part, voice coil part, fixing ring around the edge, or frame and terminal part are integrally molded, reducing speaker assembly costs and improving frequency characteristics and operational stability. It has a remarkable effect on the

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional speaker, and FIG. 2 is a sectional view of a vibration system of the speaker of the present invention. 1 is a diaphragm portion, 2 is an edge portion, 3 is a voice coil portion, 4 is a vibration system fixing ring portion, and 5 is a terminal portion.

Claims (1)

[Claims for Utility Model Registration] 1 At least the diaphragm part 1 of the diaphragm part 1, the edge part 2, the voice coil part 3, the fixing ring or frame 4 on the outer periphery of the edge part, and the terminal part 5 that constitute the speaker vibration system. , edge part 2, fixing ring or frame 4 on the outer periphery of the edge 3
In a speaker having a vibration system in which the above parts including parts are integrally molded, each part of the integrally molded vibration system is made of montmorillonite with a hardening agent or hardening accelerator adsorbed between the layers, a thermosetting resin monomer, carbon fiber or silicon carbide. A speaker characterized in that it is made of a composite material whose main material is a high-rigidity fiber such as a whisker, and which is made by uniformly mixing the above-mentioned main materials and curing the mixture by heating. 2. The speaker according to claim 1, wherein the thermosetting resin monomer is an epoxy resin monomer.