JPS6129599B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a speaker diaphragm having a sanderch structure with excellent frequency characteristics in the high range.

Physical properties generally required for speaker diaphragms include:
(a) The areal density may be small, and (b) the specific elastic modulus E/ρ may be large. (E: elastic modulus, ρ: density).

Reducing the areal density is necessary to reduce the weight of the diaphragm and increase the sound pressure. Increasing the comparative elastic modulus is also necessary in order to expand the range of piston movement of the speaker.

In order to meet the above-mentioned physical properties required for a speaker diaphragm, a speaker diaphragm has been developed that has a structure in which a honeycomb core made of a thin film of metal or polymeric material is used as the core material, and thin films of fiber-reinforced plastic are bonded to both sides of the honeycomb core. .

Conventionally, a method for manufacturing a speaker diaphragm having a three-layer sandwich structure in which a thin film of fiber-reinforced plastic is bonded to both sides of a core material such as the honeycomb core described above is as follows. The surface in contact with the honeycomb core, which will serve as the core material, is roughened with sandpaper, etc., and a liquid adhesive or film adhesive is applied to the skin material and pasted on both sides of the honeycomb core, so that the honeycomb core is seated. Generally, a manufacturing method has been adopted in which a moderate amount of pressure is applied from the outside of the skin material to cure and bond the skin material.

In the above manufacturing method, adhesive must be used for the skin material in order to bond the skin material to the honeycomb core as the core material, which increases the weight of the speaker diaphragm, reduces the sound pressure, and deteriorates the characteristics of the honeycomb structure diaphragm. There were some flaws that I couldn't get enough of. In addition, from the manufacturing process perspective, the manufacturing process is extremely complicated, including molding the skin material, sanding the adhesive surface of the skin material, applying adhesive, and bonding and molding the honeycomb structure sanderch board, resulting in expensive speaker vibration. It had the drawback of becoming a board.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and when manufacturing a speaker diaphragm having a three-layer sandwich structure,
A fiber-reinforced plastic base material, such as glass fiber cloth or carbon fiber cloth, is placed in a mold with unevenness that matches the shape of the speaker diaphragm, and a resin such as epoxy resin or non-carbon fiber is used to make the reinforced plastic. By impregnating the cloth with something like saturated polyester resin, and at the same time, before the resin of the skin material hardens, a honeycomb core as a core material is placed on top of the skin material, and the uneven mold is closed and hardened. The purpose of this invention is to reduce the amount of resin as an adhesive as much as possible, reduce the weight of the speaker diaphragm, increase the specific elastic modulus E/ρ, and manufacture it very easily.

An embodiment of this invention will be described below. FIG. 1 is a schematic cross-sectional view of a speaker diaphragm having a three-layer sandwich structure according to an embodiment of the present invention, and FIG. 2 is a perspective view of an aluminum honeycomb core 2 used as a core material. To manufacture a diaphragm for a Sanderch structure speaker, first, as shown in FIG.
A glass cloth 5 serving as a base material for the skin material is brought into close contact with the convex mold 4, and the glass cloth 5 is impregnated with an epoxy resin 6. Next, as shown in FIG. 4, while rotating the molds 3 and 4, the entire surface is uniformly impregnated with the epoxy resin 6 using a spatula 7 or the like. Then, as shown in Fig. 5, the aluminum honeycomb core 2 is sandwiched between the concave mold 3 and the convex mold 4, the mold is closed, and a bolt 8 is installed in the center of the mold.
The nut 9 is tightened, and the product is placed in a constant temperature bath 10 shown in FIG. 6 to be heated and hardened to produce a speaker diaphragm.

The speaker diaphragm manufactured as described above can significantly reduce the amount of adhesive used to bond the core material and the skin material compared to conventional manufacturing methods, resulting in a lighter speaker diaphragm and higher sound pressure. Moreover, since the specific elastic modulus E/ρ increases, the effect of expanding the region of piston movement of the speaker becomes large. In addition, there is little variation in the adhesive strength between the skin material and the core material, resulting in stable quality, and because the molding of the skin material and the adhesion of the skin material and the core material are performed at the same time, the manufacturing process can be greatly shortened.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a speaker diaphragm having a three-layer sandwich structure, Fig. 2 is an external perspective view of an aluminum honeycomb core as a core material, and Fig. 3 is a vibration plate for a speaker with a three-layer sandwich structure according to the present invention. 4 is a cross-sectional view showing the state in which the skin material of the plate is molded; FIG. 4 is a cross-sectional view showing the state in which the resin for the skin material molded in FIG. 3 is impregnated while rotating the mold with a spatula in order to make it uniform. , Fig. 5 is a cross-sectional view showing the state before the skin material 1 and the aluminum honeycomb core 2 are sandwiched between the molds and heated and hardened, and Fig. 6 is a sectional view showing the state before heating and hardening of the diaphragm for a three-layer sandwich structure speaker. FIG. In addition, the same reference numerals in the figures indicate the same or corresponding parts, 1 is fiber reinforced plastic which is the skin material, 2 is
is an aluminum honeycomb core as a core material, 3 is a concave mold for molding, 4 is a convex mold for molding, 5 is glass cloth as a base material for the skin material, 6 is an epoxy resin for the skin material, 7 is a molding spatula, 10 is This is a constant temperature bath for heating and curing.

Claims (1)

[Claims] 1 A three-layer sandwich structure with a honeycomb core made of a thin film of metal or polymer material, or a core material with a structure in which a part of it is cut out to increase flexibility, and a thin film of fiber-reinforced plastic bonded to both sides of the honeycomb core. In the speaker diaphragm, a cloth-like base material made of an inorganic or polymeric material, which serves as the skin material, is tightly attached to the mold with unevenness that matches the shape of the speaker diaphragm, and a thermosetting resin is used as the base material. A manufacturing method that simultaneously manufactures a speaker diaphragm with a three-layer sandwich structure by sandwiching the core material between concave and convex molds and applying pressure from both sides before the impregnated resin hardens.