JPS6347039B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diaphragm for a speaker, and provides a diaphragm for a speaker that can reduce high-frequency resonance peaks.

When a flat diaphragm is used as a diaphragm of a speaker, the above-mentioned effect is not present, so that flat frequency characteristics can be obtained up to the high-frequency resonance point. In order to expand the band, it is necessary to improve the specific elastic modulus (E/P) of the diaphragm, but as the specific elastic modulus improves, the high-frequency resonance also increases. etc., the peak is cut electrically or it is used in a substantially narrow band. Other methods for cutting the high-frequency resonance peak of the diaphragm include using a high mechanical loss material in combination with the surface material, or using a high mechanical loss material in the voice coil connection portion. However, these methods have drawbacks such as a reduction in the reproduction frequency band and a decrease in efficiency due to an increase in weight.

The present invention eliminates the drawbacks of the above-mentioned conventional example and efficiently realizes high-frequency resonance peak cutting.
This effect is demonstrated in flat plate diaphragms with a Sanderch structure in which a surface material is bonded to the surface of a core material.

A feature of the present invention lies in the use of a surface material of a diaphragm having a sanderch structure having partial slit-like cuts. By optimally selecting the cut shape, position, and size, it is possible to greatly reduce the high-frequency resonance peak without significantly lowering the reproduction frequency band.

A conventional example and an embodiment of the present invention will be described below.

Conventional Example In FIG. 1, 1 is a honeycomb core material, and surface materials 2 and 2' made of 30 μm aluminum foil are adhered to the front and back surfaces of this core material 1 using film adhesives 3 and 3'. This film adhesive 3,
3', film adhesives 3, 3' are interposed between the core material 1 and the surface materials 2, 2',
The adhesive film 3, 3' is melted and bonded by heating. The completed diaphragm has a thickness of 3
mm, diameter 8cm, weight 2.5g. In FIG. 1, 4 is a cylindrical coil bobbin fixed to the lower surface of the diaphragm, and a voice coil 5 is wound around this coil bobbin 4. The diaphragm is supported by the frame via an edge member, and the voice coil 5
is inserted into the annular magnetic gap of the magnetic circuit.

Embodiment As shown in FIGS. 2 and 3, surface materials 2 and 2' are bonded to the front and back surfaces of a core material 1 using film adhesives 3 and 3', as in the conventional example. In the example, concentric partial slit-shaped cut portions 6 are formed at six locations on the surface material 2, 2'. Note that the cut portion 6 is formed at the surface material 2.
This is the difference between 2' and 2'.

Figure 4 shows a speaker a using the conventional diaphragm described above.
and shows the sound pressure frequency characteristics of speaker b using the diaphragm of the present invention, and when partial slit-shaped cut portions 6 are formed in the surface materials 2 and 2' as in the present invention, The peak value in high-frequency resonance can be reduced to 1/4 or less of that of the conventional example, and as a result, a more even sound pressure frequency characteristic can be obtained up to the high frequency range.

In the above embodiment, the slit-shaped cut portions 6 are formed on both the surface materials 2, 2', but the cut portions 6 may be formed on only one surface material. Further, the shape of the cut portion 6 is not limited to a circular shape, and a radial cut portion may be formed. In addition, when forming the slit-shaped cut portions 6 on both the surface materials 2 and 2', and when forming the cut portions 6 at the same location, the rigidity of the diaphragm may decrease. When forming the cut portions 6 at 2', it is preferable to form the cut portions at different locations as in the embodiment shown in FIG.

Although the above embodiment is an example of a circular diaphragm, the present invention is not limited to a circular diaphragm, and the same applies to a rectangular diaphragm or the like.

The present invention has the above-mentioned configuration, and can reduce the peak value in high-frequency resonance, and can obtain sound pressure frequency characteristics that are even in the high-frequency range.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional speaker diaphragm, FIG. 2 is a sectional view of a speaker diaphragm according to an embodiment of the present invention, FIG. 3 is a top view of the same, and FIG. 4 is a diaphragm of the present invention. and a sound pressure frequency characteristic diagram of a speaker using a conventional diaphragm. 1... Heart material, 2, 2'... Surface material, 3, 3'...
Film adhesive, 4... Coil bobbin, 5...
Voice coil, 6... Cutting section.

Claims (1)

[Claims] 1. A speaker diaphragm having a sandwich structure in which surface materials are bonded to the front and back surfaces of a core material, in which a plurality of partially concentric slits are formed in at least one of the surface materials.