JPS601999A - Manufacture of voice coil - Google Patents

Abstract

PURPOSE:To adhere closely and strongly a bobbin and a coil even with any kind of bobbin material and insulating paint by adhering closely the coil to the voice coil bobbin having small holes through the utilization of anchoring effect. CONSTITUTION:Polyimide is impregnated with do glass cloth of the bobbin 1. Small holes 2 are made with an equal distance along the circumference of the upper end and the lower end of the contact part of the coil of the bobbin 1. Further, a polyimide insulating paint 4 is coated to the coil 3', after heating the coil 3' for 10min at 120 deg.C and for 20min at 200 deg.C, the coil is wound on the bobbin 1. The upper end and the lower end of the coil 3 are covered thinly with the paint and the paint is coated so as to be impregnated into the small holes 2 for a small amount, the coil is heated for 10min at 120 deg.C and for 20min at 200 deg.C and further heated and cured for 30min at 300 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a voice coil to be attached to an acoustic diaphragm of a speaker or the like.

Conventional configuration and its problems The required properties of the voice coil bobbin (hereinafter referred to as bobbin) around which the voice coil of a speaker etc. is wound are lightweight, high rigidity, excellent heat resistance, and resistance to temperature and humidity. It is stable and does not deform, and it also has good compatibility with adhesives and good adhesion to coils.

Traditionally, high heat-resistant bobbin materials are lightweight, highly rigid,
Polyimide is used because it is stable with respect to temperature and humidity and has excellent heat resistance. However, polyimide has poor compatibility with adhesives and has problems with adhesion to coils. For this reason, when a material with poor adhesiveness such as polyimide is used as a bobbin material, attempts have been made to improve the adhesiveness by subjecting it to surface treatment, but the effect is insufficient and the cost increases. In addition, polyimide insulation paint, which has excellent heat resistance, is being used to improve the heat resistance of voice coils, but polyimide insulation paint has poor adhesion to bobbin materials, so it must be modified or mixed with other resins. Adhesion has been improved by mixing. However, this improvement in adhesion has the disadvantage that the heat resistance of the insulating paint decreases.

OBJECTS OF THE INVENTION The present invention provides a method for manufacturing a voice coil in which the bobbin and the coil can be firmly bonded even when a bobbin material with poor adhesiveness or an insulating paint is used.

Structure of the Invention The present invention provides a method for firmly adhering the bobbin and the coil using a bobbin material with poor adhesion or an insulating paint with poor adhesion by providing a small hole in the bobbin and utilizing the anchoring effect. This is a voice coil manufacturing method that can be used.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, numeral 1 is bobean, which is a glass cloth impregnated with polyimide. Reference numeral 2 designates several small holes equally spaced along the circumference of the upper and lower ends of the contact portion of the first coil of the bobbin. 3 is a coil, which is made of polyimide, such as Trenice@2000 (Toshi product name)
After applying an insulating paint of 12C) and heating it for 10 minutes at 200°C and 20 minutes at 200°C, wrap it around the bobbin 1.

In Fig. 2, the upper and lower ends of the coil 3 are thinly covered with TRENICE@2000, and a small amount is applied to the small holes 2, and heated at 120°C for 10 minutes and 20°C for 20 minutes.
It is a cross-sectional view of a state in which it was further heated and cured at 300° C. for 30 minutes. 4 is this insulating paint.

In the state shown in FIG. 1, the paint has completely turned into polyimide and has not been cured, and is in the state of polyamide, which easily dissolves in the applied TRENICE #2000. Then it was 120℃ again.
When heated for 10 minutes at 200°C, 20 minutes at 200°C, and 30 minutes at 300°C, it becomes one with the Trenice #200o applied later, and the entire body becomes polyimide and hardens, creating a strong voice with strong adhesion between bobbin 1 and coil 3. A coil is obtained. Although polyimide bobbin material and insulating paint have been described here, this manufacturing method is not limited to bobbin imide, and can be used with any bobbin material or insulating paint, regardless of the adhesion between the bobbin material and insulating paint. Even with this, the resulting voice coil has a strong adhesion between the bobbin and the coil. Further, the small holes may be provided not only at the upper end and the lower end of the coil, but also between them.

Effects of the Invention As described above, the present invention makes it possible to create a voice coil with strong adhesion between the bobbin and the coil, regardless of the bobbin material or insulating paint, by using the anchoring effect to bring the coil into close contact with the voice coil bobbin provided with small holes. can get.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a state in which a coil is wound around a bobbin provided with small holes, and Fig. 2 is a sectional view of a main part in a state in which the bobbin and the coil are brought into close contact using the anchoring effect of insulating paint. 1...Bobbin, 2...Small hole, 3...
...Coil, 4...Insulating paint.

Claims (1)

[Claims] A method for manufacturing a voice coil, characterized in that a coil is brought into close contact with a voice coil bobbin provided with small holes by utilizing an anchoring effect.