JPH0456520B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method of manufacturing a speaker vibrating structure, and in particular, it provides a method of manufacturing a speaker vibrating structure consisting of a combination of a plurality of structural members. Here, the term "speaker vibration structure" refers to a structure that includes at least a diaphragm part and a voice coil frame part, and is made up of a plurality of structural members. Background Art and Its Problems The physical properties required of a speaker diaphragm are (1) high Young's modulus, (2) low density, and (3) large internal loss. With such materials,
It widens the Vistonik movement band, suppresses unnecessary peaks, and enables high frequency playback with less distortion. However, with conventional acoustic materials, there has been a tendency to create a contradiction in that increasing the Young's modulus of the diaphragm material generally reduces internal loss. Various methods have been studied to increase Young's modulus, and diaphragms made of metals and inorganic materials are being actively developed. However, there are no useful metal materials other than beryllium, which has a toxicity problem, and ceramic materials, which have recently been attracting attention, have high Young's modulus ceramics, which have a large specific gravity and are difficult to sinter. There's a problem. Methods for forming a desired ceramic layer on a metal base material with a relatively high Young's modulus by chemical or physical methods include electron beam evaporation, sputtering, ion plating, CVD, etc. However, both require special equipment and have the problem of high costs.
Furthermore, in this method, since the base material is much thicker than the ceramic layer, the contribution rate of the properties of the ceramic layer is not very high. As described above, it is difficult to provide a speaker diaphragm that simultaneously satisfies the physical properties (1) to (3) above using conventional materials. Additionally, a honeycomb diaphragm has been introduced as a diaphragm with structurally improved rigidity. In a honeycomb structure, vibrations are propagated in the radial direction, so it is necessary to have high radial rigidity, and the surface skin material is subject to both tensile and compressive forces, so it is necessary to have a small elongation modulus. required. In addition, it is difficult to mold a speaker diaphragm having a complex shape not only with a honeycomb structure but also with a ceramic material. In any case, to improve performance, materials with low specific gravity and good physical properties are required, but the dilemma is that it is difficult to obtain a material that satisfies all of these properties. OBJECTS OF THE INVENTION An object of the present invention is to provide a method for manufacturing a speaker vibration structure that satisfies the characteristics (1) to (3) above at the same time. Further, according to the present invention, it is also possible to provide a method for manufacturing a vibrating structure made of a ceramic material that integrates two or more structural members, such as a voice coil frame and a diaphragm. Furthermore, it is also possible to provide a method for manufacturing a ceramic vibrating structure having a complicated shape such as a honeycomb structure. Summary of the Invention In order to achieve the above object and provide a speaker vibration structure with excellent reproduction characteristics, a method for manufacturing a speaker vibration structure according to the present invention includes impregnating an organosilicon polymer that becomes ceramic by firing. molding two or more constituent members including the diaphragm portion using a material that can be easily molded; adhering or joining the two or more constituent members; By impregnating each of the constituent members, and by firing the two or more bonded or bonded and impregnated constituent members, the easily moldable material is composited with the ceramics from the organosilicon polymer and is integrally molded. Obtaining a speaker vibrating structure, and having the following configurations. The organosilicon polymer used in the method of the present invention, which becomes ceramics by firing, has a skeleton.

[Formula] Mainly composed of bonds and has a number average molecular weight of about 100 to 100
Examples include polysylmethylene polymers having a molecular weight of about 50,000 to 20,000, preferably about 500 to 20,000. These are generally called polycarbosilanes. These organosilicon polymers can be synthesized, for example, by a method of thermal decomposition condensation of monosilane, a method of thermal decomposition condensation of polysilane, and the like. In addition, the material that is easy to mold for molding two or more constituent members used in the method of the present invention (hereinafter referred to as "substrate material") may be either a natural polymeric substance or a synthetic polymeric substance. Examples include organic polymeric substances. Examples of polymeric substances include cellulose, protein, isoprene, bits, lignin poval, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, furan resin, polyester, and polyolefin. Examples include polystyrene, phenolic resin, polyamide, polyimide, polyamideimide, polybenzimidazole, polyurethane, polyphenylene sulfide, polyphenylene oxide, polysulfone, and polyfluoroethylene. It will be done. These base material materials can be easily formed into constituent members of a speaker vibration structure, and when fired in a vacuum or non-oxidizing atmosphere, they form a structure consisting of fibrous, granular and/or thin film carbon. can do. The timing for impregnating the organosilicon polymer into the base material is before the base material is formed into a constituent member, after the base material is formed into a constituent member and before adhesion or bonding, or before adhesion or bonding is performed. Impregnation may be performed later or before firing, or impregnation may be performed multiple times by combining these periods. The amount of organosilicon polymer impregnated into the base material is 50 to 200% based on the weight of the base material, whether it is impregnated before molding or after molding.
%. If a speaker diaphragm is manufactured outside this range, it will not be possible to obtain a speaker diaphragm having the preferable physical properties described in (1) to (3) above, and a speaker diaphragm that integrates a voice coil frame and a diaphragm will not be produced. If manufactured, there would be further disadvantages in terms of weight or strength of the voice coil frame. According to the method of the present invention, a molded article constructed by adhering or bonding two or more constituent members and impregnating it with an organosilicon polymer can be produced in a vacuum or in a non-oxidizing gas atmosphere such as an inert gas at a temperature of about 700 to 2,000 yen. °C, preferably about
It is fired at a temperature range of 800-1800℃. Further, the organosilicon polymer in the molded body can be made infusible at a stage before this firing, so that the above-mentioned firing can be performed in a better condition. This infusibility can be achieved by leaving it in an atmosphere of one or more gases selected from air, ozone, oxygen, and halogens, especially oxidizing gases, for several minutes or more, or by heating it from above room temperature to about 300°C. A method of heating at a low temperature, or, if oxidation is not preferred, a method of irradiating with ultraviolet rays, γ-rays, or electron beams at room temperature in a non-oxidizing atmosphere such as vacuum or inert gas can be used. Through this infusibility step, crosslinking with the base material in the molded article can be achieved. This crosslinked structure can prevent volatilization or melting of the organosilicon polymer during the firing process, and can increase the firing residue rate. Further, in this infusibility step, even if the base material in the molded article melts or softens during the heating process, deformation of the molded article due to melting or softening can be prevented by making the organosilicon polymer infusible. Examples The shape of the diaphragm portion of the speaker vibrating structure manufactured according to the present invention may be any of a cone shape, a dome shape, and a honeycomb shape. In particular, in the case of a dome-shaped diaphragm, as shown in FIG. 1, a diaphragm 1 impregnated with an organic silicon polymer solution and a voice coil frame 2 are bonded together and then fired. Furthermore, in the case of a dome-shaped diaphragm with an integrally molded edge portion, as shown in FIG. A viscous liquid of an organosilicon polymer is used as an adhesive to bond and integrate the parts before firing, and after the bonded portion is treated to be infusible, the whole is impregnated with an organosilicon polymer solution and fired to form a speaker vibrating structure. Unify. Furthermore, in the case of a honeycomb type diaphragm, as shown in FIG. 4, two surface layers 6 and 7 and a honeycomb core layer 8 impregnated with an organosilicon polymer that becomes ceramic by firing are bonded together. The bonded surface layers 6, 7 and honeycomb core layer 8 are impregnated with the organosilicon polymer and then baked to be integrated, and a normal paper voice coil frame 9 is bonded to one surface layer 7. Accordingly, a speaker vibrating structure as shown in FIG. 3 can be obtained. Next, specific examples of the present invention will be described with reference to the drawings. Specific example 1 Disperse 5g of cotton linter in water and make paper to 205×
After sufficiently dehydrating a 255 mm wet paper, a part of it was pressure-molded in a mold having the shape of a diaphragm with an edge part 4a shown in Fig. 2, and dried to a thickness of about 50 μm. A paper molded article was obtained. This paper molded article shrinks by 35% in both length and width during the subsequent firing process, so it is shaped to a large size with this shrinkage in mind in advance. Approximately 5% of SiC fibers, whiskers, etc.
By containing the above amount, this shrinkage can be reduced to substantially zero. The paper molded article was molded so that the dimensions after firing were as shown in FIG. 2. R = 30 mm, H = 6 ± 0.5 mm, h = 4 ± 0.5 mm, D = 29 ± 0.2 m, L = 41 ± 0.5 mm This paper molded body is made of the same material and has the same inner diameter D.
After bonding and integrating the voice coil bobbin with the diaphragm-shaped paper molded body using a viscous liquid of an organosilicon polymer as an adhesive, the bonded portion is
Infusibility treatment is performed in air at 200 to 300℃, and then the whole is reduced to a number average molecular weight that includes some siloxane bonds.
It was immersed in a 20wt% xylene solution of polycarbosilane 1300 and dried at below 50°C. The amount of polycarbosilane deposited was 191 mg. Next, this paper molded body was dried and subjected to the above-mentioned infusibility treatment, and then heated to 600 °C at a temperature increase rate of 100 °C/h in a nitrogen atmosphere furnace, and thereafter at a temperature increase rate of 200 to 300 °C/h. It was heated to 1200°C, held at that temperature for 10 minutes, and then cooled to room temperature. In this way, a speaker vibration structure made of a silicon carbide-carbon composite material was obtained. The wet paper of the cotton linter was impregnated and fired in the same manner as described above to form a flat plate with a thickness of approximately 50 μm without pressure forming using a mold. We then measured its properties as a diaphragm material and obtained the following results. Density = approximately 2-24 g/cm ³ , Young's modulus = 10 ² GPa, resonance sharpness = approximately 100. When we measured the reproduction characteristics of the fired speaker vibration structure (Fig. 2), we found that this structure was suitable for high-fidelity reproduction in terms of output frequency characteristics, reproduction band, and efficiency, as expected from the characteristic values of the flat fired product. It was hot. Specific Example 2 A speaker vibrating structure including a honeycomb type diaphragm was manufactured as follows. In Figures 3 and 4, chemical pulp or other suitable paper material is used as the base material for the two surface layers 6 and 7.
Paper with a thickness of 200 to 220 μm is made using the normal manufacturing method,
This is pressed to 140 mm in consideration of the final finished thickness.
Adjust the thickness to ~150μm, vertical: 34.5mm horizontally,
Two substrates weighing 50-60 mg were obtained. On the other hand, for the honeycomb core layer, a honeycomb with a cell size of 3 mm and a core thickness of 3 mm is formed using 100 μm thick kraft paper, and like the surface layers 6 and 7, the final required dimensions are 24 mm each in length and width. −30
% and -25% baking shrinkage in the thickness direction, the base material was cut to 34.2 mm in both length and width to obtain a base material weighing approximately 100 mg. The process of impregnating this core layer with a 10 to 20 wt% solution of organosilicon polymer in xylene and drying it is repeated 2 to 5 times, and when the weight after impregnation reaches 120 to 150 mg, some of the xylene solvent is volatilized at room temperature. Then, hot air drying is performed at 200 to 220°C for 30 minutes for both air drying and infusibility (polymerization). Organosilicon polymer xylene 10 used for impregnation
~Volatilize xylene from a 20wt% solution to 5000~
An appropriate amount of adhesive 10 having a viscosity of 8000 cps is applied to both the upper and lower end surfaces of the honeycomb core base material, and the previously obtained surface layer base material is adhered. This adhesive is of course turned into SiC by firing and becomes a part of the honeycomb structure, and may be formed into a sheet and placed. After drying the adhesive layer with hot air for 15 to 20 minutes at 200℃ to make it infusible, the weight is 200 to 220 mg.
xylene 10 ~ again to the honeycomb structure formed with
The process of impregnating with a 20wt% solution and drying is repeated an appropriate number of times. At this time, the amount of impregnation is 6 to 8% per step.
To increase. Once the appropriate weight is reached, dry and infusible.
After heating at 200 to 220°C for 20 to 30 minutes, the honeycomb structure was held between graphite plates and heated at 1100°C in nitrogen.
Bake at ~1200℃ for 10-30 minutes. As a result, vertical:
Width 24mm each, thickness 2.5-2.7mm, total weight 150-220mg
An integrated inorganic honeycomb structure was obtained. A voice coil frame 9 having a diameter of 17 mm was adhered to this honeycomb structure to obtain a speaker vibrating structure. When the output frequency characteristics of this vibrating structure were measured, as shown by the solid line in FIG.
Compared to the previous model, the reproduction band was expanded and the peaks and valleys of the divided vibration bands were small, making it suitable for high-fidelity reproduction. Effects of the Invention In the method for manufacturing a speaker vibration structure according to the present invention, two or more structures including a diaphragm portion are formed using an easily moldable material that can be impregnated with an organosilicon polymer that becomes ceramic by firing. Molding a member, adhering or joining the two or more constituent members, impregnating each of the two or more constituent members with the organosilicon polymer, and firing the bonded or bonded and impregnated two or more constituent members. By doing so, a speaker vibrating structure in which the easily moldable material is composited with the ceramics made from the organosilicon polymer and integrally molded is obtained. Therefore, according to the present invention, a ceramic vibrating structure having a complicated shape can be manufactured very easily, and there is no fear of uneven thickness of the ceramic vibrating structure. Furthermore, the constituent members including the diaphragm portion are made of an easily moldable material that can be impregnated with an organosilicon polymer that becomes ceramics by firing.
Because it is integrally molded from a ceramic matrix, it can simultaneously satisfy low density, high Young's modulus, and high internal loss, which were difficult to obtain with conventional materials. A speaker vibrating structure having excellent reproduction characteristics can be provided.

[Brief explanation of drawings]

1 to 4 each show an example of a speaker vibration structure manufactured by the manufacturing method of the present invention, and FIG. 1 shows the first example,
FIG. 2 is a sectional view of a structure in which a dome-shaped diaphragm and a voice coil frame are integrated by adhesive bonding, and FIG. 2 shows a second embodiment, in which a dome-shaped diaphragm and a voice coil frame are integrated by adhesive A sectional view of the structure, FIG. 3 shows a third embodiment, and a sectional view of a speaker diaphragm having a honeycomb-type diaphragm, and FIG. 4 shows each of the honeycomb-type diaphragms shown in FIG. FIG. 5 is a perspective view showing the member, and FIG. 5 is a graph showing the reproduction output frequency characteristics of the speaker vibrating structure manufactured according to the present invention. In addition, in the symbols used in the drawings, 1,
4... Vibration plate, 4a... Edge portion, 2, 5, 9...
...Voice coil frame, 3...Voice coil, 6,7
. . . surface layer, 8 . . . honeycomb core layer, 10 . . . adhesive.

Claims (1)

[Scope of Claims] 1. Molding two or more constituent members including a diaphragm portion using an easily moldable material that can be impregnated with an organosilicon polymer that becomes ceramics by firing; Impregnating each of the two or more constituent members with the organosilicon polymer; Burning the two or more constituent members that have been bonded or bonded and impregnated. 1. Obtaining a speaker vibrating structure in which ceramics made from the above organosilicon polymer are composited with a readily available material and integrally molded. 2. The method of manufacturing a speaker vibration structure according to claim 1, wherein the adhesive used for the bonding includes an organosilicon polymer that becomes ceramics upon firing.