JPS63287195A - Diaphragm for electro-acoustic transducer - Google Patents

Abstract

PURPOSE:To realize a diaphragm with high elasticity and high loss by using continuous alumina fiber of a high elastic modulus, and combining the among the fibers with a metal, a inorganic substance, an organic substance, or others. CONSTITUTION:A continuous alumina fiber of a high elasticity having an elastic modulus of 10X10<3>kgf/mm<2> or higher is used, and a metal, or a nonorganic substance, or an organic substance, or a mixture of the two of these substances are packed among the fibers to combine them. For the combination substance, aluminum epoxy resin, phenol resin, etc., can be used. To produce this diaphragm, first, one of the said substances is added to the said continuous fibers, then the mixture 1 is injected to metal dies 2, 3 from an inlet 4 and cooled to be solidified. As a result, the diaphragm with high elasticity and high loss can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a diaphragm for electroacoustic transducers having high elasticity and high loss.

(Summary of the Invention) The present invention provides a diaphragm for an electroacoustic transducer that uses high-modulus alumina continuous fibers as a base material, and uses metals, inorganic substances,
The diaphragm is bonded and filled with an organic substance or a mixture thereof to obtain a diaphragm with high elasticity and high loss.

(Prior Art and Problems to be Solved by the Invention) Conventionally, speaker suspension plates have been made by molding plastic films, woven fabrics, metal plates, etc., or by paper-molding natural fibers or synthetic fibers. Many of the things that are made are used. However, since these have a small elastic modulus, it has not been possible to obtain good frequency characteristics. In order to improve this problem, attempts have been made to improve the elasticity of the diaphragm by using carbon fiber having high elasticity. Although carbon film is chemically stable to organic substances, it has weak adhesion to organic substances and has a limited number of additives, making it impossible to obtain a sufficient composite effect.

In addition, metals such as aluminum produce aluminum carbide in the joints when molded at high temperatures, and this product has low mechanical strength, making it difficult to obtain sufficient composite effects. ing.

(Means for Solving the Problems) The present invention aims to eliminate these drawbacks and, in particular, to provide an imaging plate having 8 elasticity and high loss.

The alumina continuous fibers that can be used in the present invention contain Al2O3 in a weight ratio of 40-6 or more and have the following physical properties.

Fiber diameter: 3~20μm Specific gravity: 2.6~3.9! ! J Strong I
I: 100 to 250K (lL'11m2 Tensile modulus: 10 to 40 x 103 gf/mm2 The interfiber bonding material includes light metals such as aluminum, and the inorganic substance includes inorganic binders (product names: Kanbe CF, LA
: Manufactured by Kansai Paint Co., Ltd.).

As the organic substance, epoxy resin, phenol resin, polypropylene resin, vinyl chloride resin, etc. can be used. Furthermore, as the interfiber bond and filler, it is possible to use not only the above-mentioned metals, inorganic substances, and organic substances alone, but also mixtures thereof.

Next, the present invention will be explained in detail. Note that the embodiments are merely illustrative, and it goes without saying that various changes and improvements can be made without departing from the spirit of the present invention.

(Example 1) The alumina continuous fiber used was Denka alumina long fiber (trade name of Denki Kagaku Kogyo Co., Ltd.), and I! Miscellaneous characteristics are shown in Table 1.

Table 1 Table 2 shows the physical properties of a unidirectionally reinforced epoxy resin prepared from the present fiber, glass fiber, and carbon fiber. The amount of fiber blended at this time was 60% in terms of volume fraction.

Table 2 Table 3 shows the physical properties when unidirectionally reinforced aluminum was produced using this fiber. The fiber composition at this time is 50 in terms of volume fraction.
%.

Note that the present invention is preferably used as a skin material for a flat plate diaphragm having a honeycomb core structure.

(Example 2) Tensile modulus is 16X10' gf, 'mm2 [lI
Alumina continuous fiber with a diameter of 1011 m and a length of 0.5 to 1 mm
35% by weight of aluminum cut into pieces and heated and melted
Added.

As shown in FIG. 1, this mixture 1 is injected through the injection port 4 of a mold consisting of an upper mold 2 and a lower mold 3, and is cooled and solidified. 5 is gas venting. The physical properties of the photographic plate obtained in this way, which has a thickness of approximately 100 μl1), are that the tensile strength is approximately 5 times that of 100% aluminum, and the tensile modulus is approximately 2.
I got twice as much.

(Effects of the Invention) As described above, the present invention provides a diaphragm with high elasticity and high loss by using alumina continuous fibers and bonding and filling the fibers with metal, inorganic material, organic material, or a mixture thereof. can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the manufacturing state of the present invention.

Claims (1)

[Claims] Alumina continuous fibers with an elastic modulus of 10 x 10^3 Kgf/mm^2 or more are used, and metals, inorganic substances,
Combined with organic substances or a mixture of two or more of these,
A diaphragm for an electroacoustic transducer characterized by being filled.