JPS59117398A - Diaphragm for speaker and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture easily a diaphragm made of a hollow core by fitting a slit to sides other than a base of a triangle where each side of a regular polygon drawn on a core member made of a metallic foil as the base, and bending the slit so as to arrange it to a prescribed pattern. CONSTITUTION:A cell pattern 2 comprising lots of regular polygons is drawn on the metallic foil 5 forming the core member of the diaphragm. Further, the slit 1 is fitted to sides other than the base of each triangle where each side of, e.g., a regular hexagon is taken as the base. Further, the metallic foil 5 is clipped between female and male metallic dies 3, 4 having the same pattern as the cell pattern 2 and having a clearance corresponding to the thickness of the metallic foil 5 and is pressed. Then, the metallic foil 5 is cut off into a circle having a prescribed diameter. The core member which comprises the hollow core taking the tip of each folding piece as a paste margin and arranging into a prescribed pattern is formed. A metallic plate is stuck to the core member by an adhesives as the surface member. Thus, the manufacturing process is simplified and the metallic diaphragm having excellent characteristics is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a speaker diaphragm made of a sand inch structure in which surface materials are bonded to both sides of a core material, and a method for manufacturing the same.

Conventional configurations and their problems In general, it is considered ideal for a speaker diaphragm to vibrate as a piston over the famous frequency band used, and the sound pressure frequency may cause the diaphragm to deform during vibration or cause split vibration. Characteristics, distortion factor 1 phase characteristics, etc. deteriorate, which impedes high-fidelity reproduction. In order to solve these problems, a flat plate diaphragm made of a sandwich structure using an aluminum honeycomb core as the core material has recently been adopted, but the production cost of the aluminum honeycomb core is extremely high due to the complicated manufacturing process. The disadvantage is that it is expensive. Furthermore, metal foil such as aluminum has low elongation, so if it is deep drawn into a honeycomb shape by press forming or the like, the foil will break and cannot be used as a core material.

Therefore, instead of using aluminum honeycomb, a method is being considered in which a plastic film is heat-formed in one step and used as a core material. However, the elastic modulus of plastic, which is the core material, is significantly lower than that of aluminum, and diaphragms made of this core material have low rigidity, the piston vibration area is narrow, and it is difficult to secure a sufficiently wide playback band. .

OBJECTS OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned conventional drawbacks and provide a high-performance speaker diaphragm at low cost.

Structure of the Invention The spill force diaphragm of the present invention has a core material made of metal foil, a triangular bent piece whose base is each side of a polygon, and a plurality of bent pieces of the plurality of bent pieces. The feature is that the tip is a hollow core with cells arranged in a predetermined pattern that are bent as glue allowances. According to this configuration, cuts such as slits or grooves are provided radially from the center of each cell portion arranged in a predetermined pattern on the metal foil, and then the cut portions corresponding to the cell portions having the radial cuts are provided. It can be molded using a concavo-convex mold.

During this forming process, the slits provided in the cells widen, or the concave grooves are cut and widened, making it possible to perform deep drawing without the drawback of low elongation of the metal material, which was previously complicated. Even aluminum honeycomb core materials that require extensive manufacturing processes can be formed in one step. Therefore, a diaphragm using such an integrally molded aluminum honeycomb core material provides a speaker diaphragm with high rigidity, high performance, and low cost.

Example Examples of the present invention will be described below.

<Example 1> Al foil (thickness 201 mm) 5 is cut radially with a cutter or the like from the center of the hexagon toward each vertex as shown by the solid line in FIG. 1, and slits 1 are made. Next, as shown in FIG.
Then, as shown in FIG. 2, the hexagonal cell pattern 2 is press-molded to a height of 0.9 mm using the male and female molds 3 and 4 so as not to shift. In this case, the male and female molds 3 and 4 are provided with unevenness corresponding to the hexagonal cell pattern 2 shown by the dotted line in FIG. Next, the above AI
The foil was cut into a circular shape with a diameter of 2.8 mm to form a hollow core material.

When press-formed in this way, a hexagonal cell is formed into a predetermined shape, which has triangular bent pieces with each side of the hexagon as the base, and where the tips of the plurality of bent pieces are bent as glue allowances. The core material may be made of Al and consists of hollow cores arranged in a pattern. Next, a surface material was laminated to this core material to form a tweeter diaphragm having a diameter of 28 mm. At this time, an Al foil (thickness: 20 μm, diameter: 2 smm) was used as a surface material, and a polyamide film adhesive was used as an adhesive. The sound pressure frequency characteristic of a speaker assembled using this diaphragm is shown by curve a in FIG. 3. In addition, the sound pressure frequency characteristics (see the curve in Figure 3) of a conventional tweeter speaker whose core material is aluminum honeycomb are shown for comparison. The diaphragm according to this example can be manufactured by the manufacturing method described above, is lower in cost than conventional aluminum honeycomb, and has excellent sound pressure frequency characteristics as shown in Fig. 3. .

In Example 1, the core material was formed by making slits 1 along the solid lines in Figure 1, or instead of forming slits, A4 foil (thickness: 40 μm) 5 was formed along the solid line pattern as shown in Figure 4. ○. A concave groove 8 is formed by etching to a depth of 1 μm, and this can be press-formed in the same manner as in Example 1 to obtain a similar core material. In this case, since the etched pattern portion is cut first during press molding, the molding can be completed in the same manner as in Example 1 in which slits were made.

<Example 2> As shown in FIG. 5, an Al foil (thickness: 20 μm) is cut radially from the center of a triangle toward each vertex using a cutter or the like to form slits 9.

Next, the triangular cell pattern 10 shown by the dotted line in FIG.
The height of the A4 foil with the slits 9 is set to ○ so that the pattern does not shift using a male mold with a corresponding unevenness and a clearance equal to the thickness of the Al foil. Press mold to gmm. This is cut into a circle with a diameter of about 28 cm to obtain the core material. A surface material was bonded to this core material to form a tweeter diaphragm with a diameter of 28 mm.

In this case, the surface material was Al foil (thickness: 20 μm).

28 mm in diameter), and a polyamide film adhesive was used as the adhesive. Figure 6 shows the sound pressure frequency characteristics of a speaker assembled using this diaphragm.

In the above embodiments, the cell pattern of the core material is hexagonal or triangular, but the cell pattern is not limited to this, and the same effect can be obtained with polygonal shapes such as quadrangular, pentagonal, and decagonal. Furthermore, the diameter of the core material is not limited to 28 mm, but can be freely changed according to the required characteristics, and can also be used as a diaphragm for larger-diameter squawkers and woofers.

Effects of the Invention As detailed above, according to the present invention, it is made of metal foil,
The core material is a hollow core having triangular bent pieces whose bases are each side of a polygon, and in which cells arranged in a predetermined pattern are formed by bending the tips of the plurality of bent pieces as glue allowances. However, cuts such as slits or grooves are made in advance radially from the center of each cell arranged in a predetermined pattern in the metal foil used as the core material, and the metal foil has unevenness corresponding to the cell pattern with these cuts. By press-forming using male and female molds, the metal foil can be molded into a predetermined shape in one step without destroying it. In other words, by making cuts in the metal foil in advance, it becomes possible to perform deep drawing that cannot be formed using only the elongation rate of the metal, and the core material can be formed in such a single step. For this reason, the conventional manufacturing process for aluminum honeycomb (adhesive is applied to Al foil in strips in different patterns, a predetermined number of foils with different application patterns are laminated alternately, and cut according to the height of the diaphragm) is used. ,
This cut material is expanded and used as a core material), which is much easier to manufacture and lower in cost.

Since the core material is still metal, the characteristics of the diaphragm are as good as those of aluminum honeycomb, and it has the advantage of producing a high-performance speaker compared to diaphragms made of other plastic materials.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the slit pattern and molding pattern of the core material according to the present invention, Fig. 2 is a schematic explanatory diagram of the same forming method, and Fig. 3 is a diagram showing the sound of the speaker diaphragm of the present invention and the conventional speaker diaphragm. 4 is a cutaway perspective view of a main part of a pot explaining another molding method; FIG. 5 is a diagram showing a slit pattern and a molding pattern in another embodiment of the present invention; FIG. Figure 6 is a sound pressure frequency characteristic diagram of the same diaphragm. 1.9...Slit pattern, 2. IQ・・
・Cell pattern of heartwood, 3, 4... Mold, 5.
...Ae foil, 8...Etching groove. Name of agent: Patent attorney Toshio Nakao and 1 other person58
5 Figure 2 Figure 3 (dB+ -X number, Figure 4 Figure 5 Figure 6 Figure 86-

Claims (2)

[Claims] (1) Consisting of a sandwich structure in which surface materials are bonded to both sides of a metal core material, the metal core material has triangular bent pieces whose bases are each side of a polygon, and the plurality of the above-mentioned 1. A diaphragm for a speaker, characterized in that it is a metal hollow core in which cells are arranged in a predetermined pattern, each of which is bent using the tips of its bent pieces as adhesive margins. (2) Cuttings such as slits or grooves are made radially from the center of each cell arranged in a predetermined pattern on the metal foil, and then a concavo-convex mold is formed corresponding to the cell portion having the radial cuts. The metal foil is formed by forming a triangular bent piece with each side of the polygon as the base,
A core material such as a metal hollow core is obtained in which cells are arranged in a predetermined pattern by bending the tips of the bent pieces as adhesive margins, and then surface materials are bonded to both sides of the core material. A method for manufacturing a speaker diaphragm.