JPS58182995A - Diaphragm for speaker - Google Patents

Abstract

PURPOSE:To obtain a diaphragm having high internal loss with a light weight, by folding a plate body made of paper impregnated with viscous elastic member in zigzag, and expanding the plate in ring shape so that the one side is taken as an inner circumference and the other side is taken as an outer circumference, and bonding a surface member on both sides of the member. CONSTITUTION:The surface member 2 is bonded on both sides of a ring shaped frame member 1 to form a flat diaphragm 3, and a long rectangular shaped plate 4 made of the member 1 is folded in zigzag with an equal pitch. The plate is expanded so that one side 4a is taken as the inner circumference and the other side 4b is taken as the outer circumference. The member 1 is made of special paper where latex is impregnated to craft paper, and aluminum foil having a prescribed thickness as a surface contact member 2 is thermally adhered on both the sides of the member 1 by using a polyamide film adhesives to form the diaphragm. The sound pressure characteristics at high frequencies are made flat to attain high performance speaker, allowing to obtain the diaphragm with light weight, high rigidity and high internal loss.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm for a speaker, and particularly an object of the present invention is to provide a diaphragm for a speaker that is lightweight, has high rigidity, and has high internal loss.

Paper cones are generally used as diaphragms for speakers.

Metal bars, various foams, honeycomb materials, and the like are each used depending on the purpose, but none of them satisfy all of the characteristics required for the diaphragm, and each has its advantages and disadvantages. Speaker diaphragms using aluminum honeycomb materials have been proposed in the past in order to be lightweight and have high rigidity, but these have had the disadvantage of being difficult to process and form, and also being heavy. Further, when a planar diaphragm is constructed using a sandwich structure having the aluminum honeycomb material as a core material, a major drawback is that a sharp peak occurs in the sound pressure characteristics at the resonance frequency. The larger the sound pressure peak at fh, the narrower the usable flat frequency band, making it difficult to design a speaker system.

The present invention eliminates these drawbacks and flattens the sound pressure characteristics in the high range, thereby achieving higher performance of the speaker.

The present invention will be described below with reference to drawings of embodiments.

FIG. 1 shows an embodiment of the present invention. In FIG. 1, 1 is an annular skeleton member, and 2 is a surface material adhered to both sides of this annular skeleton member 10, which constitutes a flat diaphragm 3. are doing.

The annular skeleton member 1 is made by bending a long rectangular plate-like body 4 into a zigzag shape at equal pitches as shown in FIG. 2, and as shown in FIG. Inner peripheral edge, other side (4
It is developed into an annular shape with the outer peripheral edge (B side) and its both end surfaces are glued together. Highly elastic sheets serving as surface materials 2, 2 are adhered to both surfaces of the frame member 1 formed into an annular shape as described above. Here, for the above-mentioned skeleton member 1, a special paper having a density of 0.91 and a thickness of 80 μm, which is obtained by impregnating kraft paper with 6 to 10% (weight ratio) of latex, was used. Also.

Both surfaces of the skeleton member 1 have a thickness of 50 mm as surface materials 2, 2.
A diaphragm was made by thermally adhering μm aluminum foil using a polyamide film adhesive.

A diaphragm with a thickness of 6 mm and an outer diameter of 190 mm was created using the method described above, and the anechoic chamber characteristics (1 m/IW, JIS standard box) were measured when this was used as a 26 mm diameter speaker.
It is shown in Figure 4. Figure 4d shows the sound pressure frequency characteristics of this example, and for comparison, Figure 4d shows the characteristics of a speaker made in the same way using a Noricam material made of aluminum with a core material of 2.0 μm. show. As is clear from the results in Figure 4, while having fh equal to that of conventional speakers,
An ideal speaker with a small fh peak can be obtained. This is because the braking effect at fh is effective because a composite material of paper and viscoelastic material with a large internal loss is used for the core frame member. In addition, the manufacturing method of the skeleton member as the core material of this example is simpler than that of the conventional non-nicum material, so it has the advantage that a high-performance speaker diaphragm can be manufactured at low cost.

In addition, although the above embodiment described a flat plate diaphragm,
As shown in FIG. 6, this can be used as a cone-shaped diaphragm 6 to increase the rigidity and increase the fh of the speaker.

As described in detail above, according to the present invention, a rectangular plate-shaped body is bent into a zigzag shape and expanded into an annular shape so that the - side becomes the inner circumferential surface and the other side becomes the outer circumferential surface. Since the surface material is bonded to both sides of this annular frame member, it has the advantage of being easier to manufacture than the conventional honeycomb core material, and the frame member is made of composite paper impregnated with a viscoelastic material. Since a rectangular plate-like body is used, it is possible to reduce the peak of fll and flatten the sound pressure frequency characteristics, and the viscoelastic material is structurally impregnated into a bent skeletal member with a zigzag shape. This has the advantage that only the peak can be reduced without any decrease in 1 h.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing one embodiment of the speaker diaphragm of the present invention, Fig. 2 is a perspective view of a skeleton member used in the diaphragm before development, and Fig. 3 is a sectional view of the skeletal member used in the diaphragm. A top view, FIG. 4 is a comparison diagram of the sound pressure frequency characteristics of the speaker diaphragm of the present invention and a conventional speaker diaphragm, and FIG. 5 is a sectional view showing another embodiment of the speaker diaphragm of the present invention 9. It is. 1... Skeleton member, 2... Surface material. Name of agent: Patent attorney Toshio Nakao and one other person? Figure 2 Figure 3

Claims (1)

[Claims] A rectangular plate-like composite of paper impregnated with a viscoelastic material is bent into a zigzag shape, and expanded into a ring with the inner circumferential surface on the negative side and the outer circumferential surface on the other side. A speaker diaphragm made by bonding surface materials to both sides of the component.