JPS61107898A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To improve a characteristic of a diaphragm by forming a ceramics layer at the surface and rear of a mesh-shaped base material and laying the mesh-shaped base material in the ceramics layer with the mesh-shaped base material composed by weaving and knitting a silicone carbide fiber as a core base. CONSTITUTION:A diaphragm for the speaker 1 covers the surface and rear of the mesh-shaped base material 2 with a ceramics layer 3 and the base material 2 is laid in the ceramics layer 3. The base material 2 consists of a woven or knitted silicone carbide fiber. As a ceramics, for example, a colloidal solution of alumina is impregnated to the mesh-shaped base material composed of the silicone carbide fiber, and after wind-drying, the preburning is executed at 100 deg.C for 3hr in the heating furnace, and thereafter, the temperature gradually rises, when the burning is executed at 1,100 deg.C for 3hr, an alpha-alumina is obtained. Thus, the brittleness in the ceramics single body is deleted, as well as a tensile strength, and the amplitude of an elastic modulus of the silicone carbide fiber improve the characteristics as the diaphragm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a diaphragm used in a speaker.

[Prior art and its problems]

The characteristics of a speaker diaphragm include being lightweight, having a large Young's modulus, and having a moderately large internal loss. Paper, resin, metal, etc. are materials that meet these characteristics. Can be mentioned.

Since these base materials have drawbacks when used alone, they are often used as a mixture or composite with other materials.

For example, paper diaphragms are made by mixing glass fibers or collagen into pulp to improve heat and moisture resistance, or by mixing carbon fiber to improve Young's modulus and heat resistance. be.

Further, a fiber-reinforced composite material imaging plate is also known.

For example, carbon fibers are plated, or carbon fibers are impregnated with thermosetting resin and cured.

In addition, alumina fibers and nitrided boron fibers have been developed, but the materials themselves are expensive and cannot be accepted in the general market, and their strength deteriorates significantly at high temperatures, so they do not allow vibrations. There was a problem that it did not fit well as a board.

[Purpose of the invention]

The purpose of the present invention is to overcome the problems of the conventional diaphragm mentioned above,
DESCRIPTION OF THE PREFERRED EMBODIMENTS An object of the present invention is to provide a speaker diaphragm that can satisfy required characteristics in a well-balanced manner.

〔Example〕

FIG. 1 is a sectional view of a speaker diaphragm 1 according to an embodiment (dome type) of the present invention, and FIG. 2 is an enlarged sectional view of section A thereof.

In Fig. 2, 2 is a mesh base material made of woven and knitted silicon carbide fibers, 3 is a ceramic layer formed on the front and back surfaces of the mesh base material 2, and the mesh base material 2 is embedded in the ceramic layer 3. has been done.

FIGS. 3 and 4 are diagrams for explaining a method of manufacturing a speaker diaphragm according to the present invention.

In FIG. 3, IA is a diaphragm fabric made of a mesh base material impregnated with a ceramic colloidal solution in advance;
4 is a pair of molds provided above and below.

In FIG. 4, IB is the diaphragm material temporarily formed by the above-mentioned mold 4, and while being sandwiched between the molds 4 from above and below, the whole is placed in a heating furnace 5, fired, and released from the mold. After cooling, a speaker diaphragm as shown in FIG. 1 is obtained.

In the present invention, the silicon carbide fibers that govern the characteristics of the speaker diaphragm have the following physical characteristics.

Fiber diameter -10~12μm Specific gravity = 2.8 Tensile strength = 250~300kg/+n'' Elastic modulus =
20 X 103kg/va2 Ceramics include alumina Aβ203, zirconia ZrO2, titania T i O2, mullite 3A7!203 2S
io2, chromia Cr2O3, magnesia MgO, beryllia BeO% silica SiO2, titanium carbide T
For iC% carbide, boron 84C1 silicon carbide SiC and silicon nitride 5i3f%L can be used.

For example, a colloidal solution of alumina is impregnated into a mesh base material made of silicon carbide fibers, and after air drying, it is heated in a heating furnace for one hour.
After pre-baking at 00℃ for 3 hours, the temperature was gradually raised to 11
When fired at 00° C. for 3 hours, α-alumina was obtained as the ceramic layer 3, and the diaphragm made of the silicon carbide fiber mesh base material was lightweight and highly rigid.

〔Effect of the invention〕

Since the speaker diaphragm of the present invention has the above configuration,
The following effects can be achieved.

■ As the interlining of the composite uses a mesh base material made of woven and knitted silicon carbide fibers, it eliminates the brittleness of the ceramic alone, and also has the tensile strength and elasticity of the silicon carbide fibers themselves. The large ratio improves the characteristics as a diaphragm.

■ Ceramic layers cover the front and back surfaces of the mesh base material, and the mesh base material is embedded within the ceramic layer, so the entire diaphragm forms a membrane with no air leakage, allowing for imaging with less split vibration. It can be made into a board.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a speaker diaphragm according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of section A in Fig. 1, Fig. 3 is a front view of the mold, and Fig. 4 is a heating It is a sectional view of a furnace. DESCRIPTION OF SYMBOLS 1...Speaker diaphragm, IA, IB...Diaphragm fabric, 2...Mesh base material, 3...Ceramics layer, 4
... Mold, 5... Heating furnace. Patent applicant Pioneer Corporation Figure 1 I Figure 2 ■ Figure 3 4 Go to 1B-6q-

Claims (1)

[Claims] A mesh base material made of woven or knitted silicon carbide fibers is used as an interlining, a ceramic layer is formed on the front and back surfaces of the mesh base material, and the mesh base material is embedded in the ceramic layer. A speaker diaphragm that is characterized by a .