JPS5955698A - Production of edge for diaphragm of speaker - Google Patents

Abstract

PURPOSE:To reduce production cost and to improve a frequency characteristic by forming many punches at the peripheral part of a sheet base material consisting of a thermoplastic resin utilizing a center part thereof for a diaphragm and press molding the peripheral part under heating to obtain an edge. CONSTITUTION:The sheet base material 2 consisting of about 0.1-0.3mm. thermoplastic resin is prepared by forming many punches 1 uniformly and dispersively on the edge place E of a circular diaphragm part D. In addition, a ring-like thermoplastic thin film sheet 3 with 15-20mum thickness is prepared so as to coincide with the edge part E. The periphery of the base material 2 is clamped by a clamper 4 and the edge part E put on the sheet 3 is arranged on a lower metal mold 7. The 1st upper metal mold 9 is dropped from the peripheral part of the base material 2 to press mold under heating the base material 2 like an edged shape and the sheet 3 is thermally melted with the base material 2. Subsequently, the 2nd upper metal mold 11 is dropped to press mold under heating the part D like a diaphragm shape. Thus, the diaphragm 12 having the edge 13 caulked with the sheet 3 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a speaker diaphragm edge for holding a speaker diaphragm to a frame or the like.

[Prior art] Edges for speaker diaphragms must have appropriate flexibility in order to hold the diaphragm in the correct position and to vibrate the diaphragm linearly in the vibration direction of the diaphragm. It won't happen. Currently, the edge material that meets these conditions is a free edge type that uses flexible cloth, urethane foam, rubber, etc., and attaches the edge material around a diaphragm that is separate from the edge material. speakers are common. However, this type of speaker
Applying adhesive to bond the diaphragm and edge material together,
Since it requires complicated manufacturing processes such as adhesion and drying, it has the drawback of poor mass productivity and high costs.

On the other hand, in contrast to this free edge type, fixed edge type speakers in which the diaphragm and the edges are integrally molded from a continuous base material are also in practical use, but it is difficult to provide the diaphragm with the necessary high rigidity. At the same time, it was difficult to obtain sufficient flexibility for the edges from the same base material as the diaphragm.

[Object of the Invention] The present invention has been made in view of the above-mentioned points, and provides a speaker vibration that can provide necessary flexibility even though it is a fixed edge type edge that is integrated with a diaphragm. The present invention provides a method for manufacturing a board edge.

[Structure of the Invention] The method of manufacturing an edge for a speaker diaphragm of the present invention includes using a thermoplastic resin sheet as a base material that will become the diaphragm and the edges, and applying a thermoplastic resin sheet to the peripheral portions of the sheet base material that are to become the edges. This is achieved by providing a large number of perforations to impart the necessary flexibility to the edge, and by pressurizing and heating the peripheral portion of the sheet base material where the perforations are provided into the shape of the edge.

[Example] An example of the method of manufacturing an edge for a speaker diaphragm according to the present invention will be described based on FIGS. 1 to 4.

First, as shown in Fig. 1, a large number of perforations (1) (1), .
A sheet base material (2) having a thickness of approximately 0.1 to 0.3 m is prepared, in which the following materials are uniformly dispersed. Thermoplastic resin is used as this sheet base material (2) in order to facilitate the subsequent heating and pressure forming. polypropylene, polyester,
Polyamide, polyvinyl chloride, etc. are suitable.

On the other hand, as shown in FIG.
A thin film sheet (3) of about 20 μm is prepared. This thin film sheet (3) is also selected from the same materials as the sheet base material (2).

Next, as shown in FIG. 3, the periphery of the sheet base material (2) is clamped with a clamper (4),
With the thin film sheet (3) placed on the edge portion E of 2), this sheet base material (2) is placed in the diaphragm-shaped recess (
5) and an annular groove (6) having an edge shape around the recess (5). Then, while heating this sheet base material (2) with hot air, a first upper plate having an annular protruding strip (8) having a 3-edge shape is inserted from above the peripheral portion of this base material (2). The shape (9) is lowered and the edge portion E of the sheet base material (2) is heated and pressure-molded into an edge shape, and the thin film sheet (3) at this portion E is thermally fused to the sheet base material. Subsequently, a second upper mold (11) equipped with a diaphragm-shaped convex portion (10) is lowered from above the center of the sheet base material (2), and the diaphragm of the sheet base material (2) is lowered. Heat and pressure mold the area into a diaphragm shape.

Thus, as shown in FIG. 4, the edge (13), which has a U-shaped cross section and is integrally connected to the periphery of the diaphragm (12) formed into a conical shape, has a flexible material attached to the edge (13). A large number of perforations (1) (1), etc. are provided to give sex,
Furthermore, the edge (13) is sealed by the thin film sheet (3) completely adhered to the upper surface of the edge (13). The flexibility of such an edge (13) is due to the flexibility of the perforation (1) (
1) It is set depending on the aperture area ratio of .

As the sheet base material (2), a composite material in which a reinforcing agent is mixed into a thermoplastic resin may be used.
There is a product in which 0% by weight and 20% by weight of scaly mica are uniformly dispersed, and if this is used, the Young's modulus as a diaphragm will be 920kg/nff1l2, and the density will be 1.17g.
/am”, the sound speed is 2.8 km/sec, and the Q value is 20.
It is possible to do this. On the other hand, the shape of the large number of perforations (1) (1), , , at the edge portion E of the sheet base material (2) is not limited to a circular shape, and may be in the shape of a slit, but these perforations (1) ( 1) It is desirable that the arrangement is isotropic in order to vibrate the diaphragm (12) with good linearity.

In addition, another example method includes perforation (1) of edge (13).
(1), , are formed with small openings, and these perforations (1) (1
),,.

By coating and filling the inside with a damping agent such as acrylic resin or urethane resin, the edges (13) can be sealed, making it possible to eliminate the need for the thin film sheet (3) in the above embodiment.

Even when using a damping agent like this, or when using a thin film sheet (3) as described above, if materials with high internal loss are selected and used, the diaphragm (12)
The resonance phenomenon of the edge (13) during driving can be suppressed, and the frequency characteristics of the speaker can be flattened.

[Effects] The method for manufacturing the edge for a speaker diaphragm of the present invention involves providing a large number of perforations in the periphery of a sheet base material made of thermoplastic resin whose central portion is used as a diaphragm, and press-heat-molding the periphery. Since the edge is obtained by using the diaphragm, there is no need to glue a separate edge to the diaphragm, which not only improves mass production, but also allows the edge to have a certain flexibility by providing a large number of holes in the edge. It becomes possible to grant the following. Furthermore, since the thin film sheet is applied to the edge where the perforation is arranged, the edge can be sealed, and furthermore, the resonance phenomenon of the edge can be suppressed by this thin film sheet.

Therefore, the method of the present invention greatly contributes to reducing the manufacturing cost and improving the frequency characteristics of speakers.

[Brief explanation of the drawing]

FIGS. 1 to 4 are process diagrams showing a method for manufacturing a 7-edge for a speaker diaphragm according to the present invention, (1) shows drilling,
<2> is the sheet base material, (3> is the thin film sheet, (7) is the lower mold, (9) and (11) is the upper mold, (12) is the diaphragm, (
13) shows the edges, respectively. Applicant Sanyo Electric Co., Ltd. Agent Patent Attorney Shizuo Sano 8-

Claims (1)

[Scope of Claims] 1) A large number of perforations are provided around the periphery of a sheet base material made of thermoplastic resin whose central portion is used as a diaphragm, and the periphery of the sheet base material where the perforations are provided is shaped into an edge shape. A method for manufacturing an edge for a speaker diaphragm, which is characterized by pressurized and heated molding. 2) A thin film sheet made of thermoplastic resin is bonded to the peripheral area of the sheet base material in which the perforation is provided, and the peripheral area is pressurized and heated into an edge shape, as described in claim 1. A method for manufacturing edges for speaker diaphragms.
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