JPS5931277B2 - Manufacturing method of speaker diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing a speaker diaphragm having a high elastic modulus.

Conventionally, paper has often been used for speaker diaphragms.

This is because paper has appropriate elastic modulus and internal loss, and can be made lighter. Recently, organic foams and metals such as aluminum have been used as materials to replace paper, but they have advantages and disadvantages, such as organic foams having a low elastic modulus, and metal diaphragms having low internal loss and increasing weight. , it cannot be said to be optimal as a diaphragm for speakers. Furthermore, in order to improve the elastic modulus of paper, diaphragms made of a mixture of inorganic fibers and organic synthetic fibers have been developed, but no significant improvement in the elastic modulus could be expected. The present invention eliminates the above-mentioned conventional drawbacks and provides a method for manufacturing a speaker diaphragm having a particularly high elastic modulus.One embodiment of the present invention will be described below.

Example High-density polyethylene fiber and carbon fiber (6mwL, fiber diameter 9μ) were mixed at a ratio of 85:15, and the fabric weight was 100/77.
A Z'' mixed paper sheet is prepared.

After vapor-depositing aluminum to a thickness of 10μ on one side of this mixed paper sheet (thickness 250μ), this mixed paper sheet was heated at a temperature of 250°C to melt the high-density polyethylene fibers that make up the mixed paper sheet, and then formed into a dome shape. do. FIG. 1 shows the completed dome-shaped diaphragm. In Figure 1, 1 is a sheet of molten high-density polyethylene containing carbon fibers, and on one side of this sheet is an aluminum layer 2.
is vapor-deposited, and the adhesion to the aluminum layer 2 is strengthened by the molten high-density polyethylene, so the elastic modulus is improved by 20% compared to the mixed sheet alone. In this example, no reduction in internal loss was observed compared to the mixed sheet alone. FIG. 2 shows the sound pressure frequency characteristics of a speaker using the diaphragm of the above embodiment and a speaker using a diaphragm made of a single mixed sheet.

According to the speaker a using the diaphragm of the present invention, the high frequency range is expanded compared to the speaker b using the diaphragm made of a single mixed sheet. Note that the present invention is not limited to the above-mentioned embodiments, and it is possible to form a metal layer on the surface of a mixed sheet with thermoplastic resin fibers or organic fibers, and to firmly adhere the metal layer with the molten thermoplastic resin. be.

Note that polyethylene fibers, polypropylene fibers, polyester fibers, etc. can be used as thermoplastic resin fibers, carbon fibers, glass fibers, alumina fibers, etc. can be used as inorganic fibers, and aromatic polyamide fibers etc. can be used as organic fibers. can. Also, the metal layer is aluminum,
Titanium, beryllium, boron, or the like may be formed by a vapor deposition method, a plating method, or the like. The thickness of the metal layer may range from several microns to several hundred microns; if it is thicker than this, the elastic modulus will improve, but
This reduces internal loss and increases the weight of the diaphragm. Further, the metal layer may be formed not only on one side but also on both sides of the mixed sheet. The present invention is a manufacturing method as described above, and particularly has the advantage of improving the elastic modulus.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a speaker diaphragm obtained according to an embodiment of the present invention, and FIG. 2 is a sound pressure frequency characteristic diagram of a speaker using the same diaphragm and a speaker using a conventional diaphragm. 1...Mixed paper sheet, 2...Aluminum layer.

Claims (1)

[Claims] 1. A sheet is prepared by mixing thermoplastic resin fibers and inorganic fibers or organic fibers, a metal layer is formed on at least one side of the mixed sheet by vapor deposition or plating, and the thermoplastic resin fibers of the mixed sheet are heated. A method of manufacturing a speaker diaphragm, which comprises melting it and then forming it into a diaphragm shape.