JPH07105985B2 - Flat diaphragm - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat diaphragm used for a flat speaker used in various audio equipment.

Configuration of Conventional Example and Problems Thereof In general, a flat panel speaker was constructed as shown in FIG.

That is, a ring-shaped magnet 3 and a ring-shaped plate 4 are laminated on a plate 2 having a center pole 1 and a frame 6 is connected on a magnetic circuit 5 formed by connecting the ring-shaped plate 4 to each other. 7, an edge 8 such as a free edge is attached, a peripheral portion of a flat plate vibration plate 9 is connected to the edge 8, and a drive cone 10 is connected to the lower surface of the flat plate vibration plate 9.
A voice coil 12 which fits in the magnetic gap 11 of the magnetic circuit 5 is connected to the central portion of the above, and the voice coil 12 is held by a damper 13.

A conventional method of manufacturing the flat plate diaphragm 9 in such a flat panel speaker will be described with reference to FIG.

That is, the core material 15 is cut to an arbitrary width (Fig. 2a), the adhesive 16 is applied at a constant interval and laminated (Fig. 2b), and when the predetermined thickness is reached, the block 17 is heated and pressure-bonded. (FIG. 2c), and the block 17 is sliced to an arbitrary width to obtain a block 18. (FIG. 2d) The block 18 is expanded to form a hexagonal honeycomb core 19 (FIG. 2e). The surface skin material 20 was adhered to both surfaces with a thermoplastic adhesive to form the flat diaphragm 9 (FIG. 2f). Such a flat plate diaphragm 9 has conventionally used a sheet made of aluminum foil or natural fiber as the core material 15. When the aluminum foil is used as the core material 15, there are drawbacks such as high cost, heavy weight, and weak adhesion to the surface skin material 20 made of aluminum foil or the like. When the natural fiber sheet is used as the core material 15, the adhesive strength with the surface skin material 20 is good, but the buckling strength when made into a honeycomb shape is weak, and there is a drawback that the reproduction frequency band is lowered.

It is an object of the present invention to eliminate the above-mentioned conventional drawbacks, and to provide a flat diaphragm that achieves high buckling strength and weight reduction at the same time and has a flat frequency characteristic at low cost. is there.

In order to achieve the above-mentioned object, the present invention is to adhere a sheet made of natural fibers to one or both sides of a metal foil, apply an adhesive agent to the combined body at a predetermined interval, and stack a plurality of sheets on top of each other. The bonded structure is heated and stretched to form a honeycomb structure, and the surface skin material is attached to the top and bottom to form a flat plate vibration plate. With this structure, high buckling strength and weight reduction are achieved. It is possible to realize a flat speaker with flat frequency characteristics.

Description of Examples Examples of the present invention will be described below.

FIG. 3 shows an embodiment of the present invention.

21 and 22 are natural fiber sheets, 23 is aluminum foil, 24 is a rotating roller, and 25 is a combination of these. That is, an acrylic adhesive is applied to the rotating rollers 24 in advance, and 10 μ of natural fiber sheets 21 and 22 each having a 7 μ aluminum foil 23 sandwiched between the rotating rollers 24 are passed through and bonded to each other. Got After that, the honeycomb core 19 is formed by the method described in FIG. 2 and the aluminum surface skin material is formed on both sides.
FIG. 4 shows the flat diaphragm 9 to which 20 is attached. This honeycomb structure is lighter in weight, has a higher internal loss, and has a larger vibration loss than the aluminum honeycomb structure. Also, the adhesive strength with the aluminum surface skin material is extremely strong. Therefore, the high frequency part of the frequency characteristic shown in FIG. 5 is particularly stable, the high frequency peak that is present in the conventional flat panel speaker A is suppressed, and the frequency characteristic is flat. FIG. 5B shows the frequency characteristics of the flat speaker using the flat diaphragm of the present invention.

EFFECTS OF THE INVENTION Since the flat plate vibration plate of the present invention is configured as described above, not only is it realized to reduce the weight, but the adhesive force between the honeycomb structure and the surface skin material is strong, and the vibration loss is remarkably large. Abnormal resonance such as resonance is effectively suppressed, and flat frequency characteristics with few peaks and dips can be obtained. Further, it is possible to provide at low cost a flat diaphragm that has higher buckling strength than the craft honeycomb and is strong against deformation due to humidity.

[Brief description of drawings]

FIG. 1 is a sectional view showing a general flat plate speaker, FIG. 2 is a process drawing showing a manufacturing method of a honeycomb core, and FIG. 3 shows a manufacturing method of a core material of a flat plate diaphragm in one embodiment of the present invention. FIG. 4 is a process diagram, FIG. 4 is a partially cutaway, partially enlarged perspective view of the flat plate diaphragm, and FIG. 5 is a flat plate speaker using the flat plate diaphragm of the present invention in comparison with a conventional flat plate speaker using an aluminum honeycomb core. 3 is a frequency characteristic diagram of FIG. 5 ... Magnetic circuit, 6 ... Frame, 7 ... Gasket,
8 ... edge, 9 ... vibration plate, 10 ... drive cone,
11 …… magnetic gap, 12 …… voice coil, 13 …… damper, 15 …… core material, 16 …… adhesive, 17 …… block, 18 …… block, 19 …… honeycomb core, 20 …… surface skin Material, 21,22 ...... Core sheet made of natural fiber, 23 ...... Aluminum foil, 24 ...... Rotating roller, 25 ...... Combined body.

Claims (1)

[Claims] 1. A sheet made of natural fibers is adhered to one side or both sides of a metal foil, an adhesive is applied to the combined body at predetermined intervals, and a large number of sheets are laminated and adhered to each other and then heated and stretched. A flat plate diaphragm in which a honeycomb structure is formed and surface skin materials are attached to the top and bottom.