JPH0119316B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm for a speaker, and an object thereof is to provide a diaphragm for a speaker that is easy to manufacture and has high rigidity.

In general, in order to expand the reproduction band (piston vibration area) of a speaker, the lighter and more rigid the diaphragm material is, the better.Furthermore, it is better to use a flat diaphragm to eliminate the front chamber effect of cone-shaped speakers. . In order to make a flat plate lightweight and highly rigid, it is thought to be best to use a sandwich structure in which a surface material with a high modulus of elasticity such as metal is bonded to a lightweight core material. Conventionally, flat plate speakers have often used a core made of aluminum honeycomb having a hexagonal cell shape, or a sandwich structure made of plastic foam as a core. however,
The manufacturing method of aluminum honeycomb is complicated and the manufacturing cost is high, making it difficult to use it as a popular stereo speaker. In addition, those using foam as a core material have a disadvantage that they have lower rigidity than honeycomb, making it impossible to obtain sufficiently satisfactory characteristics.

The present invention solves these conventional drawbacks by forming radial bending ribs on the surface of a metal foil plate, and bonding a surface material to the surface of this core material. This has the advantage that it is possible to obtain a speaker diaphragm that is easy to manufacture, lightweight, and highly rigid.

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

Example 1 As shown in Fig. 3, a plurality of radial bending ribs 1a were provided on an Al foil disk to form a core material 1, and an Al foil disk as a surface material 2 was bonded to the surface of this core material 1. . Here, the core material 1 is as shown in Figure 2.
A 28φ disc 3 is made of Al foil (thickness 20 μm), and a plurality of slits 4 are made radially in this disc 3, and slits 5 are made in the same direction at the tip. Next, by bending the portion with the slits 4 and 5 perpendicularly to the disk 3, the bent rib 1a shown in FIG.
The thickness of this core material 1 was 1.0 mm. Finally, Al (thickness: 20 μm) is laminated as a surface material to form a diaphragm. This was incorporated into a unit as a tweeter diaphragm, and its frequency characteristics were measured and are shown in curve A in FIG. In addition, a diaphragm using styrene foam (40 times foamed) as the core material and Al (20 μm) as the surface material (diaphragm thickness 2 mm)
In order to compare the frequency characteristics of the conventional example, the fourth
This is shown in curve C in the figure.

<Example 2> A core material was prepared in the same manner as in Example 1, and a polyethylene terephthalate film (thickness 40 μm) was used as a surface material.
A diaphragm made by laminating both sides of the diaphragm was assembled into a speaker unit, and the frequency characteristics were measured, as shown in curve B in FIG.

By providing slits in the metal foil and bending it to form a core material with bent ribs as in the above embodiments, it is possible to obtain a flat plate diaphragm with a sanderch structure that is simpler and cheaper than Al honeycomb. Furthermore, it provides an excellent diaphragm with higher rigidity than a sandwich structure using polymer foam as the core material.

As described above, according to the present invention, since the surface is attached to the core material in which radial bending ribs are formed on a metal foil plate, a speaker diaphragm that is easier to manufacture and has a higher rigidity than one with an aluminum honeycomb structure can be obtained. There are advantages that can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the speaker diaphragm of the present invention, FIGS. 2 and 3 are illustrations for explaining the production of the core material of the same diaphragm, and FIG. 4 is a perspective view showing an embodiment of the speaker diaphragm of the present invention. FIG. 2 is a comparative characteristic diagram of conventional speaker diaphragms. 1... Heartwood, 1a... Bent rib, 2... Surface.

Claims (1)

[Claims] 1 A disk made of metal foil is characterized by making a plurality of cuts radially from the center to form cut and raised ribs as a core material, and laminating a thin metal film or a thin polymer film to this core material as a surface material. Diaphragm for speakers.