JPH0879888A - Manufacture of voice coil - Google Patents

Abstract

PURPOSE: To reduce manufacturing cost and to make the manufacturing process and the quality of a product stable by connecting a conductive foil provided to a bobbin of a voice coil and a winding end through ultrasonic wave melting so as to simplify the processing of the winding end thereby attaining manufacturing by an automatic equipment in the manufacture of the voice coil of a dynamic speaker. CONSTITUTION: A winding start part 3a and a winding end part 3b of a winding 3 formed by winding a single layer of a flat wire are made to abut on conductive foils 2, 2 provided to a bobbin 1 without stripping off the insulation film and both are welded by applying and ultrasonic wave to the contact to manufacture the voice coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a voice coil in an electrodynamic loudspeaker, and particularly to a winding end portion of an edgewise wound voice coil in which an insulated wire having a rectangular cross section is wound around one layer. Regarding the improvement of the processing method of.

[0002]

2. Description of the Related Art In a conventional voice coil for an electrodynamic speaker, an edgewise winding voice coil, in which an insulated wire having a rectangular cross section is wound around one layer, is commonly known as shown in FIGS. The insulated wire having a rectangular cross section called a rectangular wire is wound along the bobbin 1 with the short side of the cross section of the rectangular wire being in contact with the bobbin 1 and the winding start end 3c at the upper end of the winding 3. Is drawn upward along the bobbin 1 as it is, but the winding end end 3d at the lower end is bent toward the inside of the winding 3 at the position of the gap of the seam portion of the bobbin 1, and the inner circumference of the winding 3 is kept as it is. It is pulled out upward along the surface and connected to a lead wire 4 (tinsel wire) for connection with a speaker input terminal. The winding end 3d of the winding 3 is drawn upward along the gap of the seam portion of the bobbin 1 because the diameter of the winding end drawn upward increases the wall thickness of the voice coil body. This is because, by using this structure, the substantial wall thickness can be reduced by at least the thickness of the material of the bobbin 1.

Further, since the edgewise winding voice coil has a good space factor in the magnetic air gap and is lightweight and can enhance the efficiency of the speaker, the aluminum wire is used for the winding 3 particularly for the purpose of a high-frequency speaker. Voice coil using is often used.

[0004]

In the conventional edgewise winding voice coil having such a structure, the treatment of the winding end portion, particularly the winding end portion 3d is complicated, and the rectangular wire is folded and the winding 3 is wound.
Since drawing out upward along the inner peripheral surface of the above is a manual work that requires skill and cannot be mass-produced by an automatic machine, the manufacturing cost cannot be reduced.

Further, in the voice coil having the conventional structure, since it is often connected to the lead wire 4 by soldering at the most tip end of the winding end, the insulating coating in this portion is removed in advance by pre-processing and the flux is removed. Had to be applied and placed, which also resulted in high component prices.

Further, since the insulated electric wire is forcibly bent at the winding end portion 3d, the strength of the bent portion is insufficient especially when an aluminum wire is used, and product defects due to disconnection frequently occur. There was a flaw.

In view of the above, the present invention eliminates the drawbacks of the conventional example described above and replaces the end portion of the voice coil winding with the bobbin 1.
It is an object of the present invention to provide an improved manufacturing method for obtaining a voice coil processed by using the conductive foil provided in.

[0008]

A method of manufacturing a voice coil according to the present invention for achieving the above object will be described with reference to FIGS. 1 and 2. A conductive foil 2 is formed on two surfaces of a bobbin 1 of the voice coil. , 2 are attached and the insulated wire having a rectangular cross section is wound in a single layer to form a winding start end 3a and a winding end 3b of a winding 3 of a voice coil.
In the method of manufacturing a voice coil electrically connected to the second conductive coil 2, the conductive foils 2, 2 are provided with the winding start end 3a and the winding end 3b of the winding 3 of the voice coil being provided with an insulating coating. The method of manufacturing a voice coil is characterized in that the winding ends are connected to the conductive foil by means of ultrasonic fusion.

As shown in FIG. 5, the means for ultrasonic welding comprises an oscillator 5, a magnetostrictive ultrasonic transducer 6 connected to the oscillator 5 and a jig 7 for welding. The winding start end 3a and the winding end 3b of the winding 3 are held in contact with the conductive foils 2 and 2 while the insulating coating is applied, and the ultrasonic output end of the magnetostrictive ultrasonic transducer 6 is When an ultrasonic wave is applied by pressing the portion so as to sandwich the end of the winding wire 3 and the conductive foil, friction is generated between the end portion of the winding wire 3 and the conductive foil, and the insulating film of the insulated wire is generated by frictional heat. Is melted and destroyed, and at the same time, the core wire portion of the winding wire 3 and the conductive foil 2 are directly contacted and fused.

[0010]

In the method of manufacturing a voice coil having such a structure, when manufacturing a voice coil of edgewise winding, the winding ends are formed in the same shape on the conductive foils 2 and 2 provided on the bobbin 1 in advance. It ’s just fusion,
There is no need for manual work such as folding back of a rectangular wire and drawing upward along the inner peripheral surface of the winding wire 3, which is required in the prior art.

Further, since the fusion work is performed in a state in which the insulation coating of the insulated wire is applied to the conductive foils 2 and 2 having the winding ends provided on the bobbin 1 in advance, like a conventional voice coil,
It is not necessary to remove the insulating coating in this portion by pre-processing in advance and apply flux to leave it.

[0012] In particular, even if the wire is made of a material whose surface is easily oxidized, such as an aluminum wire, the oxide film is destroyed and fused, so that no special flux is required and no trouble such as chemical corrosion occurs. .

Further, since the insulated wire is not mechanically formed into an unreasonable shape in the treatment of the winding end portion 3d, cracks are inherently present in the bent portion even when an aluminum wire is used. There is no shortage of strength of the insulated wire at the site.

[0014]

1 shows the structure of a voice coil for a speaker according to the method for manufacturing a voice coil of the present invention. Conductive foils 2 are attached in advance to two locations on the bobbin 1 of the voice coil. The insulated wire having a rectangular cross section, which is called a rectangular wire, is wound along the bobbin 1 with the short side of the rectangular wire in contact with the bobbin 1 to form a single winding 3 of the voice coil. . The voice coil is completed by electrically connecting the winding start end 3a and the winding end 3b of the winding 3 to the conductive foils 2a and 2b, respectively.

In order to electrically connect the ends of the winding 3 to the conductive foils 2 and 2, the conductive foils 2 and 2 are wound with the winding start end 3a and the winding end 3b having an insulating coating. Abutting each
It is connected by means of ultrasonic fusion.

As shown in FIG. 2, the ultrasonic welding means comprises an oscillator 5, a magnetostrictive ultrasonic vibrator 6 connected to the oscillator 5, and a welding jig 7 for welding. The winding start end portion 3a and the winding end end portion 3b of the winding wire 3 are held in contact with the conductive foils 2 and 2, respectively, while the insulating coating is still applied, to cure the end portion of the winding wire 3 and the conductive foil. When the ultrasonic wave is applied by sandwiching the base of the tool 7 and the ultrasonic output end of the magnetostrictive ultrasonic transducer 6 and applying ultrasonic waves, frictional heat is generated between the end of the winding 3 and the conductive foil, At the same time that the insulating coating of the insulated wire is melted and destroyed by the frictional heat, the core wire portion of the winding wire 3 and the conductive foil are in direct contact with each other and are also fused by the frictional heat. In this case, even if an oxide film is attached to the surface of the core wire of the winding wire 3 and the surface of the conductive foil, the insulating film is melted and destroyed, and at the same time, it is mechanically removed, so that the two are completely fused.

The means for ultrasonic fusion is not limited to the above-mentioned structure. For example, the ultrasonic vibrator uses a magnetostrictive alloy containing a rare earth element in addition to the conventional magnetostrictive type, or a ceramic. It may be electrostrictive.

Although the loudspeaker according to the present invention has been described above in detail with reference to the representative embodiment, the embodiment of the voice coil manufacturing method according to the present invention is not limited to the structure of the above embodiment. The present invention can be appropriately modified and implemented as long as it has the constituent features described in the above-mentioned claims, exhibits the action of the present invention, and has the effects described below.

[0019]

[Effect] The speaker according to the present invention has the following effects.

(1) In the edge-wise winding voice coil, the winding ends are simply fused to the conductive foils provided on the bobbin in the same shape. It is not necessary to perform manual work that requires skill such as pulling the winding wire upward along the inner peripheral surface. Therefore, not only the work cost becomes easy, but also the parts cost can be reduced because mass production can be performed by an automatic machine.

(2) Since the fusion work is performed in a state where the insulation coating of the insulated wire is applied to the conductive foil having the winding end portion provided in advance on the bobbin, this portion is preliminarily formed like a conventional voice coil. There is no need to remove the insulating coating by pre-processing and apply flux to set it. Therefore, similarly to the above, the cost of parts can be reduced by reducing the work cost.

(3) Even if the wire is made of a material whose surface is easily oxidized, such as an aluminum wire, a special flux is not required because the oxide film is destroyed and fused. Therefore, like the above effect (2), it is possible to expect a reduction in component cost.

(4) In the effect (3), the fact that no special flux is required makes it possible to obtain a product having excellent weather resistance without causing troubles such as chemical corrosion.

(5) Since there is no mechanically unreasonable shape in the treatment of the end portion of the winding as in the conventional case, cracks are inherently present in the bent portion even when an aluminum wire is used. There is no shortage of strength of the insulated wire at the site. Further, by mass-producing with an automatic machine, the quality of parts becomes uniform, and in combination with the effect (4), a highly reliable product can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view of a voice coil manufactured by a method for manufacturing a voice coil according to the present invention.

FIG. 2 is a sectional view of the voice coil of the present invention.

FIG. 3 is a perspective view of a conventional edgewise winding voice coil.

FIG. 4 is a cross-sectional view of a conventional edgewise winding voice coil.

FIG. 5 is an explanatory diagram showing a configuration of an ultrasonic fusing means according to an embodiment of the present invention.

[Explanation of symbols]

 1 bobbin 2 conductive foil 3 voice coil winding 3a winding start end 3b winding end 4 connection lead wire 5 oscillator 6 magnetostrictive ultrasonic transducer 7 jig

Claims (1)

[Claims] 1. A winding start end portion 3a of a winding 3 of a voice coil, wherein conductive foils 2, 2 are attached to two surfaces of a bobbin 1 of the voice coil, and an insulated electric wire having a rectangular cross section is wound around one layer. In a method of manufacturing a voice coil in which winding end portions 3b are electrically connected to the conductive foils 2 and 2, respectively, a winding start end portion 3a and a winding end portion 3 of a winding 3 of the voice coil are provided.
A method for manufacturing a voice coil, characterized in that b is brought into contact with the conductive foils 2 and 2 while the insulating coating is applied, and the winding end portion and the conductive foil are connected by means of ultrasonic fusion.