JPS61131699A - Diaphragm for loudspeaker and its production - Google Patents

Abstract

PURPOSE:To obtain a diaphragm for loudspeaker of excellent characteristic with wide piston motion band by providing a fibric layer of highly elastic fiber on at least the outer surface of the diaphragm base material with honeycomb core and forming a film on the surface of said fiber layer. CONSTITUTION:A cloth of carbon fiber is impregnated with an epoxy resin, and heated/pressed with the diaphragm base material with honeycomb core 2 by an autoclave method or a compression method. In this way, the honeycomb core 2 and the fiber 3 are properly bonded in the effect due to the self welding of the epoxy resin to make a structure body. Next, this body is heated and press-adhered for 30min by a metallic die for molding diaphragm which is applied with an acetate cellulose solution on its surface. Thus the diaphragm is formed with a film layer 4 consisting of acetate cellulose on its surface. The diaphragm for loudspeaker constituted in such a manner has a high elasticity and rigidity as well as heat resistance and solvent resistance and hence is of excellent characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a diaphragm for a speaker and a method for manufacturing the diaphragm, particularly a diaphragm having high elasticity and high strength.

The present invention relates to a diaphragm that is ideal for use in woofers as it not only has excellent heat resistance but also has low distortion and can expand the piston motion band, and a manufacturing method that can easily and accurately manufacture such a diaphragm. .

(Prior Art) Pulp cones and resin cones are used as conventional loudspeaker diaphragms, but these diaphragms generally have drawbacks such as insufficient rigidity and low heat resistance.

Furthermore, in order to eliminate the above-mentioned drawbacks of the pulp cone and increase the rigidity of the diaphragm, a diaphragm in which a synthetic resin layer is formed on the surface of a base cloth made of carbon fibers has also been proposed.

(Problems to be Solved by the Invention) The conventional diaphragm mainly made of carbon fiber described above lacks surface stability due to pinholes and voids in the surface resin layer, and especially when there are pinholes, air load becomes difficult to apply, causing third-order distortion.

In addition, various multilayer diaphragms have been proposed that are made of composites of a diaphragm base material and other members, but the means for connecting the diaphragm base material and other members, the means for forming the surface layer, etc. This is extremely important when trying to obtain excellent characteristics as

The first object of the present invention is to provide a piston with high elasticity, high strength, excellent weather resistance and heat resistance, and also surface stability with little distortion and significantly improve the piston motion band. The object of the present invention is to provide a diaphragm for a speaker that can perform the following functions.

Another object of the present invention is to produce a speaker which can easily produce the above-mentioned diaphragm, can accurately form a film layer of cellulose acetate on the surface during molding of the diaphragm, and has good mold releasability. An object of the present invention is to provide a method for manufacturing a diaphragm for use in automobiles.

"Structure of the Invention" (Means for Solving Problems) A speaker diaphragm according to the present invention includes a fibrous layer made of high elastic Jl material provided on at least the surface side of a diaphragm base material made of a honeycomb core. ! A film layer made of cellulose acetate is formed on the surface of the layer.

And the fibers that should be placed on the back side! ! The calendar may be made of a different type of high elastic fiber from the fiber layer to be provided on the front side.Also, a paper layer may be provided on the back side of the diaphragm base material, and a film layer made of acetocellulose may be placed on the surface of the paper layer. can also be formed.

The method for manufacturing a speaker diaphragm according to the present invention involves impregnating a woven fabric made of highly elastic W&fibers such as carbon fiber with a thermosetting resin such as an epoxy resin, and heating this and a diaphragm base material made of a honeycomb core. A structural body is obtained by applying pressure, and a diaphragm is obtained by molding this structural body under heating and pressure using a diaphragm molding die coated with an acetate cellulose solution.

(Function) The speaker diaphragm according to the present invention has a structure consisting of a diaphragm base material made of Nicum core and a fiber layer made of high elastic fibers, and has high elasticity and high rigidity, and the surface of the fiber layer has Since the film layer is made of cellulose acetate, it not only has weather resistance, heat resistance, and solvent resistance, but also has surface stability, which makes it difficult to apply air loads due to pinholes, voids, etc. Third-order distortion does not occur.

In addition, the speaker diaphragm according to the present invention includes a woven fabric made of highly elastic fibers such as carbon fiber impregnated with a thermosetting resin such as an epoxy resin, and this is placed on a diaphragm base material surface made of a honeycomb core. When this is heated and pressurized by an autoclave method or compression method, the woven fabric made of M&fibers is cured, and the honeycomb core and the woven fabric made of high elastic fibers are accurately bonded together due to the self-fusing property of the thermosetting resin. You can obtain a structure based on both.

Next, this structure is heated and pressurized with a diaphragm molding die coated with an acetate cellulose solution to form a diaphragm, and an acetate cellulose thin film is formed and fused onto the high elastic fiber base fabric.

This acetate cellulose film does not adhere to the mold and has excellent mold releasability, so it has extremely good moldability.It also has no pinholes and is effective in modifying the surface of the fiber base, and has excellent weather resistance and It has excellent heat resistance and solvent resistance.

(Example) An example of a speaker diaphragm according to the present invention will be described based on the drawings together with a manufacturing method thereof.

In the figure, reference numeral 1 indicates the entire diaphragm, and a fibrous layer 3 made of high elastic fibers is provided at least on the surface side of a diaphragm base material 2 made of a honeycomb core, and a film R4 made of acetate cellulose is provided on the surface of the mta layer 3. It is formed.

FIG. 1 shows the above fiber layer 3 and film layer 4 on a diaphragm base material 2.
Fig. 2 shows an example in which the paper layer 5 is provided on one side (front side), and Fig. 3 shows an example in which the paper layer 5 is provided on the back side, and a film layer made of cellulose acetate is provided on the surface. 6 is shown. 7 is an edge member. Note that although the illustrated example shows an example in which a cone diaphragm is used, it goes without saying that this may be a plane diaphragm.

Paper honeycomb cores are effective as honeycomb materials because they are lightweight.

In the configuration example shown in FIG. 2, the fiber Ia calendar 3 on the back side may be the same as the fiber on the front side, or may be a woven fabric or non-woven fabric made of other high elastic fibers different from this, but in any case, Since pinholes and the like are likely to appear, it is desirable to form the film layer 6 on the surface thereof.

゛ Next, to describe a manufacturing example, first, as an example, a woven fabric made of carbon fiber is impregnated with epoxy resin, and this is heated to a surface pressure of 1.0 to 1.0 by autoclave method or compression method.
Heat and pressurize at 5 Kg/Cm' and a temperature of 130°C for 30 minutes. As a result, the woven fabric made of the fibers is cured, and the honeycomb core and the woven fabric made of carbon fibers are accurately bonded to each other by the self-fusing property of the epoxy resin, so that a structure made of both can be obtained.

Next, this structure was placed in a diaphragm molding die coated with an acetate cellulose solution under the same conditions as above - i.e., a surface pressure of 1
．． When a diaphragm is molded by heating and pressing at a temperature of 0-5 g/crn' and a temperature of 130° C. for 30 minutes, an acetate cellulose thin film is formed and fused onto the carbon fiber base fabric.

"Effects of the Invention" According to the speaker diaphragm according to the present invention, it has a structure consisting of a diaphragm base material made of a honeycomb core and a fiber layer made of high elastic fibers, and has high elasticity and high rigidity, and the fiber #I
Since a film layer made of cellulose acetate is formed on the surface of the layer, it not only has weather resistance, heat resistance, and solvent resistance, but also has surface stability and is less susceptible to air loads due to pinholes and voids. Therefore, the piston motion band can be significantly expanded, and a speaker diaphragm with excellent characteristics can be obtained.

Further, the speaker diaphragm according to the present invention includes a woven fabric made of highly elastic fibers such as carbon fiber impregnated with a thermosetting resin such as an epoxy resin, and placed on a diaphragm base material surface made of a honeycomb core. When this is heated and pressurized, the woven fabric made of the fibers is cured, and the honeycomb core and the woven fabric made of high elastic fibers are accurately bonded together due to the self-fusing property of the thermosetting resin, thereby obtaining a structure made of both. This structure is then heated and pressurized in a diaphragm molding mold coated with an acetate cellulose solution to form a diaphragm.A thin film of acetate cellulose is formed and fused onto the high elastic fiber base fabric, making it easy to mold. Moreover, it can be coated accurately.

This acetate cellulose film does not adhere to the mold and has excellent mold releasability, so it has extremely good moldability.It also has no pinholes and is effective in modifying the surface of the fiber base, and has excellent weather resistance and Since it has excellent heat resistance and solvent resistance, it is possible to easily manufacture a speaker diaphragm with excellent characteristics.

[Brief explanation of the drawing]

The drawings show an example of a speaker diaphragm according to the present invention,
Figure 1 shows the fiber #i layer and film layer on one side of the diaphragm base material (
FIG. FIG. 2 is a sectional view showing an example in which paper scraps are provided on both the front and back sides, and FIG. 3 is a sectional view showing an example in which paper waste is provided on the back side and a film layer of cellulose acetate is formed on the surface thereof. l: entire speaker diaphragm, 2: diaphragm base material 3: fiber mN
, 4: Film layer, 5: Paper layer, B: Film layer.

Claims (1)

[Claims] 1. A fiber layer made of high elastic fibers is provided on at least the surface side of the diaphragm base material made of a honeycomb core, and a film layer made of cellulose acetate is formed on the surface of the fiber layer. Features speaker diaphragm. 2. The speaker diaphragm according to claim 1, wherein the fiber layer to be provided on the back side is a different type of high elastic fiber from the fiber layer to be provided on the front side. 3. The speaker diaphragm according to claim 1, wherein a paper layer is provided on the back side of the diaphragm base material, and a film layer made of acetocellulose is formed on the surface of the paper layer. . 4. A structure is obtained by impregnating a woven fabric made of high elastic fibers such as carbon fibers with a thermosetting resin such as an epoxy resin and heating and pressurizing this and a diaphragm base material made of a honeycomb core.
A method for manufacturing a diaphragm for a speaker, which comprises heating and press-molding this structure using a diaphragm molding die coated with an acetate cellulose solution.