JPS5844893A - Manufacture for speaker diaphragm - Google Patents

Abstract

PURPOSE:To easily form a diaphragm having high rigidity, by clipping a soften thermoplastic resin film heated between top and bottom dies, forming a core having a lot of projecting and recessing parts through pressure forming and sticking surface members on both sides of the core. CONSTITUTION:Recessing parts 4, projecting parts 8, projecting parts 5 and recessing parts 7 radially provided for a top metal die 2 and a bottom metal die 3 are arranged so as to be opposed respectively, and forming is done by the metal dies 2, 3 cliping a resin film 1 under vacuum. In this case, forming is done for the film 1 to be pressed on the recessing parts 4, 7, since the air in the parts 4 and 7 radially provided for the top and bottom metal dies 2 and 3 is suctioned from suction holes 6 and 9. A surface member is sticked on both sides of a core made of the resin film 1 to be formed. Thus, the core made of the film 1 has projecting parts up/downward, the strength of the core itself is large and the rigidity against bending can be improved.

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a speaker diaphragm having a side-inch structure in which surface materials are attached to both sides of a core material, and its purpose is to provide easy manufacturing and high rigidity characteristics. An object of the present invention is to provide a method for manufacturing a speaker diaphragm having the following.

In general, a speaker diaphragm is required to have high rigidity against bending in order to expand the reproduction frequency band by moving the divided resonance frequency to a higher frequency side. In order to satisfy such requirements, a speaker diaphragm with a side-inch structure has been known, which has a honeycomb structure made of aluminum with six sides and a surface texture applied to both sides. However, a Zandwich structure speaker diaphragm with a honeycomb structure is made by expanding a plurality of plate-shaped thin pieces bonded with adhesive, and the original honeycomb structure is made up of a plurality of plate-shaped thin pieces joined with adhesive and expanded. The manufacturing process of 4 itself is very complicated, resulting in high costs, and it has been kept in a state of rest in anticipation of its development as a speaker for audio equipment such as stereo receivers, radio receivers, television receivers, etc. However, in order to obtain a speaker diaphragm with a side-inch structure at a low cost, it is necessary to create a core material with many irregularities by vacuum-pressure forming a polymer resin film, and then apply a surface material on both sides of the core material. In this case, a polymer resin film of a certain thickness is heated and softened, and then molded by suction and pressure in a mold having uneven parts. The polymer resin film that is stretched by suction and pressure into the concave parts of the mold tends to be thinner than before molding, and this tendency becomes more pronounced as the depth of the concave and convex parts of the mold becomes deeper. In other words, as the thickness of a speaker diaphragm with a side switch structure using a core material made of vacuum-pressure molded polymer resin film becomes thicker, the thickness of the vertical beam of the core material becomes thinner, and the strength of the core material decreases. However, it also had the disadvantage of being low in rigidity even as a diaphragm for speakers.

The present invention solves these conventional drawbacks,
Hereinafter, a method of manufacturing a speaker diaphragm according to the present invention will be explained.

, The method for manufacturing a speaker diaphragm of the present invention involves sandwiching a polymer resin FILNO between two molds provided with four parts and a convex part facing each other on opposing surfaces. The material is softened by heating and molded by suction and pressure into the respective recesses of the two molds, and then surface materials are pasted on both sides of the molded core material made of polymer resin film.

The core material made of polymer resin film formed in this way has two protrusions that protrude downward, and if the thickness of the core material is the same, it can be vacuum-pressure molded in one mold with unevenness. It is possible to reduce the aperture ratio compared to the 6
The vertical beam of the moon can be thickened. Therefore, the strength of the heart itself is large, and the speaker vibration lT
It has the advantage that the rigidity against bending can be increased even as an il1 plate.

Next, a detailed explanation will be given based on an example. .

Example After heating a polyarylate resin film 1 manufactured by Unitika (Kiki) with a thickness of 100 μm to about 350°C to soften it,
As shown in the figure, it was inserted between the upper mold 2 and the lower mold 30. At this time, the lower metal paste 2←1 has a diameter of 28 mm, has a convex portion with a diameter of 3 Y nm at its center, and has a depth of 1 mm around this convex portion. The concave portions 4 and convex portions 6 with an opening angle of 16° were provided in a radial manner, and a suction hole 6 was provided in each of the concave portions 4 and convex portions 6 with an opening angle of 16°. It has a concave part with a diameter of 3 mm at its center, and concave parts 7 and convex parts 8 with a depth of 1.0 mm and an opening angle of 15 degrees are provided radially around this concave part. A suction hole 9 was provided in each of the holes.
The upper mold 2 and the lower mold 3 were arranged such that the concavo-convex portions at the center faced each other, and the concave portions 4 and the convex portions 'P, which were provided radially, and the convex portions 6 and the concave portions 7 faced each other.

Next, the -F lower mold 2.3 sandwiching the -J2 resin film 1 was molded in a vacuum atmosphere. At this time, as shown in FIG. 2, the resin film 1 allows the air in the four radial parts 4 and the recesses 7 provided in the upper mold 2 and the lower mold 3 to pass through the suction holes 6.9. It is molded so as to be pressed into the recesses 4 and 7 before being pulled out. The core material 12 formed in this manner has a diameter of 28 mm, a height of 2 mm, and uneven portions 10 and 11 extending radially, as shown in FIG.
I got it.

After that, a thin aluminum plate with a thickness of 20 μm was bonded to both sides of the Kishingetsu 12 as a surface material using an adhesive,
I got a speaker diaphragm for the tweeter.

The high frequency limit frequency of the speaker diaphragm configured in this way/
h is shown in Table 1. Moreover, the core material 12 formed as described above
Table 1 shows the thickness A of the convex portion 11, the thickness B4 of the concave portion 10, and the thickness C of the vertical beam.

Comparative Example A polyarylate resin film 21 of Unitika (II ff) having a thickness of 1001 m was heated to about 350° C. to soften it and then placed opposite to a mold 22 as shown in FIG. has a diameter of 28 mm and a convex part with a diameter of 3 mm (7) at its center, and a depth of 2.0 mm around this convex part.
Concave portions 23 and convex portions 24 with an opening angle of 16° in mm were provided radially, and a suction hole 25 was provided in each of the concave portions 23. Next, the mold 2 facing the resin film 21
In No. 2, the resin film 21 was molded in a vacuum atmosphere. At this time, the resin film 21 is molded so that it is pressed against the four radial parts 26 so that the air in the four radial parts 23 provided in the mold 22 can be extracted from the suction holes 25, as shown in FIG. As a result, the diameter is 28mm,
A core material with a height of 2 mm and uneven portions extending radially was obtained. Thereafter, thin aluminum plates with a thickness of 20 μm η were bonded to both sides of the core material using an adhesive to form a speaker diaphragm for a tweeter.

The upper limit frequency f of the speaker diaphragm configured in this way is
h is shown in Table 1. Further, Table 1 shows the thickness A of the convex portion, B of the concave portion, and the thickness C of the vertical beam of the core material formed as described above.

As is clear from Table 1, the molding method of this example
The film thickness C of the vertical beam is about 1.6 times thicker than the core material made by conventional molding method, and as a result, the rigidity against bending as a speaker diaphragm is higher and the upper limit frequency is also lower. You can see that it's getting higher.

In the above embodiments, a polyarylate resin film was used as the core material, but other than toba, thermoplastic resin films such as vinyl chloride, polyethylene, polypropylene, polycarbonate, polyacetate, etc. can also be used. In addition, in the example described above, the pattern of the core material was made into a radial uneven shape, but in addition to this, it could also be made into a triangular shape, a five-circular shape,
A pattern such as a rhombus or a hexagon may be used, and the same effect can be obtained even if the shape is an aggregate pattern thereof.

Further, in the embodiments described in (-), 6 pieces were formed by vacuum forming, but in addition to this, 6 pieces may be formed by pressure forming or vacuum pressure forming. 1. In the case of air pressure molding, holes for pressurization are also provided in each of the radial convex parts 5 and 8 of the upper and lower molds 2 and 3, and compressed air is sent through these holes to form the four opposing parts 4.
．． The resin film 1 may be pressure-bonded to the 7.
At this time, the suction hole 9 is simply used as an escape hole for the air in the recesses 4 and 7. In addition, in the case of vacuum-pressure molding, holes for pressurization are provided in each of the radial convex parts 6 and 8 of the upper and lower molds 2.3, and compressed air is sent through these holes, and vacuum is drawn through the suction holes 9. Then, the recesses 4 of the upper and lower molds 2 and 3
, 7, and press the resin film 1 onto each of them.'': Yes. Moreover, it is needless to say that the core material 12 having a plurality of irregularities may be bonded with the surface material after removing the soil surface and lower surface 9/- of the irregularities.

As described above, according to the present invention, the thickness of the vertical beam of the core material can be formed thicker, so the strength of the core material itself is increased, and the rigidity against bending as a speaker diaphragm is increased. Therefore, the upper limit frequency can be moved to the higher side, and a wider band can be achieved. However, since the core material is formed by molding, the structure is simpler and easier to assemble than when a conventional honeycomb structure is used as the core material, and it is highly anticipated that it will be used in popular audio equipment.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams for explaining the manufacturing process of the speaker diaphragm of the present invention, Figure 3 is a plan view of the core material used in the same diaphragm, and Figures 4 and 6 are the conventional FIG. 3 is a diagram illustrating the manufacturing process of a speaker diaphragm. 1...Resin film, 2...2 molds, 3...Lower mold, 4. Finished... Concavity, 6,
8...Convex part, 6,910 z(--yu... Suction hole, -10...Concave part, 1
1...Protrusion, 12...Heartwood. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 3 Figure 4

Claims (1)

[Claims] The convex part of the upper mold and the four parts of the lower mold are arranged so as to face each other, and a thermoplastic resin film that is heated and softened is sandwiched between these two lower molds to perform direct air molding or pressure molding. Alternatively, a method for producing a diaphragm for a speaker, comprising forming a core material having a large number of irregularities by vacuum-pressure forming, and then bonding surface materials to both sides of the core material.