JPS5915369B2 - Method for manufacturing self-supporting coils - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a self-supporting coil that is excellent in workability in a range shape.

Conventionally, when manufacturing a self-supporting coil, a self-bonding insulated wire (hereinafter referred to as a "fused wire") made by baking a composition mainly composed of thermoplastic synthetic resin was used, and the method described below was used. It is known to bond the fused coatings of fused wires together to form a coil.

[1] External heating method A method in which a fused wire is wound around a winding frame to form a coil, and then heated from the outside to fuse the fused layer film and form a coil.

[2] Electric heating method A method in which a coil is formed by winding a fused wire around a winding frame, and then a coil is formed by passing an electric current through the conductor and using the heat generated to fuse the fusion layer film.

[3] Solvent bonding method A method in which a fused wire is immersed in a solvent and wound around a winding frame to form a coil, and the wires are bonded together to form a coil.

In particular, the current heating method is widely used as a method for manufacturing deflection coils for televisions because it allows coils with complex shapes to be produced with high efficiency.

On the other hand, as the quality of electrical equipment has recently improved and costs have been reduced by 10%, it has become necessary to improve the heat resistance of self-supporting coils and to mold them into more complex shapes. In order to improve the heat resistance of self-supporting coils, it is necessary to maintain the coil shape in a slightly high temperature atmosphere, and a fusion layer with a high heat distortion temperature is required. In addition, in order to form a coil with a complex shape, it is necessary to wind up the fused wire smoothly against the winding frame, and it is necessary to have sufficient surface smoothness so that the wire distribution density of the coil does not change when heated. Despite the deviations in temperature distribution caused by uniformity, it is required that each part of the coil be sufficiently bonded. As a solution to this problem, [1] change the composition of the fusion layer.

[2] Changing the amount of current during electrical heating.

Various studies have been conducted on this, but in the former case, it is difficult to satisfy both properties because heat resistance and adhesion are inversely related, and in the latter case, it is difficult to satisfy both properties by extending the energizing time or applying a large current. , the adhesion will improve in the parts of the coil where the wire distribution density is low, but on the other hand, the temperature will rise significantly in the parts of the coil where the wire distribution density is high, leading to thermal deterioration and thermal softening, which will have a negative impact on the electrical insulation properties of the wire coating. give. Furthermore, since the coil temperature becomes high, when the coil is taken out from the winding frame, the distortion of the coil becomes large, so it is necessary to extend the cooling time, which has the disadvantage of causing a decrease in coil production efficiency. Recently, self-supporting coils have become smaller and more complex, and when coils are formed by the current heating method, deviations in temperature distribution due to uneven distribution density of wires in the coil are further increasing.

Deviations in temperature distribution caused by non-uniform wire distribution density in the coil are caused by differences in heat dissipation during electrical heating. That is, it is related to the thermal conductivity of the winding frame material, and when a material with high thermal conductivity is used, the amount of heat generated by electrical heating is relatively smoothly conducted to the winding frame. The portion of the coil where the electric wire distribution density is low has a large contact ratio with the winding frame, and conducts a large amount of heat, making it difficult for the temperature of the fusion wire itself to rise. The same is true for areas with a high wire distribution density, but the contact ratio with the winding frame is small, and the temperature of the fused wire itself increases. In addition, when a material with low thermal conductivity is used, the amount of heat generated by electrical heating is difficult to conduct, and while the temperature rises in the parts of the coil with a low wire distribution density, the temperature rises in the parts of the coil with a high wire distribution density. The amount of heat generated is stored internally, and the temperature of the fusion wire itself rises significantly. This slope ζ becomes more significant as the amount of current applied or the time of current applied is increased.

Conventionally, the material for the winding frame was hemlock iron and its chrome-plated products,
Aluminum and epoxy resin composites mixed with aluminum powder are used. , the cooling time of the coil is extended, which is a disadvantage that requires attention in terms of coil production efficiency.

As a result of various studies, the present inventors have found that when combining materials with high thermal conductivity and materials with low thermal conductivity as the winding frame material in accordance with the wire distribution density of the coil in the winding frame for coil forming, the temperature distribution of the coil is The inventors have discovered that it is possible to increase the coil production efficiency because the deviation is small and the energization conditions can be relaxed without impairing adhesiveness, and the present invention has been achieved.

To this invention, a coil is manufactured by an electric heating method in which a self-fusion insulated electric wire is wound around a winding frame to form a coil, the coil is fused by electric heating, the coil is cooled and formed, and the coil is removed. Therefore, the surface of the winding frame material with high thermal conductivity is in contact with the part of the coil where the wire distribution density is high, and the surface of the winding frame material with low thermal conductivity is in contact with the part of the coil where the wire distribution density is low. The present invention relates to a method for manufacturing a self-supporting coil, which is characterized by using a winding frame having a material surface with partially different thermal conductivity.

In the present invention, the self-bonding insulated wire is one that is usually commercially available, and is made of polyurethane, formal, polyester, polyesterimide (or other synthetic resin that has been insulated in advance) on the conductor, and then polyvinyl butyral, polyamide, epoxy, etc. It refers to a product formed by baking a heat-softening resin mainly composed of resin or the like as a fusion layer using a conventional method.

Current heating method is a method in which a fused wire is wound around a winding frame to form a coil, and then an electric current is passed through the conductor and the heat generated is used to fuse the fusion layer film to form a coil. There is a method for manufacturing a coil for a television deflection yoke.

It is desirable to use a high current short time method as the energization condition. The wire distribution density of a coil is the wire distribution density in each part forming the coil.
It represents the state of gathering of fused copper wires, where the high part is where the coil shape is thick and densely gathered, and the low part is where the coil shape is thin and gathered in parallel.

The coil winding frame is assembled in accordance with the coil shape design so that a material with high thermal conductivity is in contact with the thick part of the coil shape, and a material with low heat conductivity is in contact with the thin part of the coil shape.

The material with high thermal conductivity may be any metal, but iron and its alloys, plating materials, and aluminum and its alloys can generally be used in view of the durability of the winding frame.

Substances with low thermal conductivity are those whose thermal conductivity is relatively lower than metals, such as ceramics, heat-resistant synthetic resins (for example, polytetrafluoroethylene, phenolic resin, epoxy resin), and composites thereof. things are available. The method of manufacturing the winding frame is not particularly limited, but from the viewpoint of durability, iron chrome plating is used as the base material, and ceramics, heat-resistant synthetic resin, etc. are embedded and pasted in the parts of the coil where the wire distribution density is low. When using a winding frame with partially different thermal conductivity according to the present invention, it is preferable to apply a coating or coating.Compared with the conventional winding frame made only of materials with high thermal conductivity, the wire distribution density of the coil is lower during electrical heating. Because the temperature rises easily in low-temperature areas, the amount of current flowing can be relaxed without impairing adhesion.On the other hand, since the temperature rise in areas with high distribution density can be suppressed, it is possible to improve the electrical insulation properties of the wire coating. The negative effects are eliminated, and damage caused by layer shorting of the coil and thermal deterioration can be prevented.

Furthermore, when the coil is left to cool, the portions with high wire density where the coil temperature tends to rise come into contact with the surface of the material with high thermal conductivity, thereby preventing an extension of the cooling time.

In addition, compared to when using a winding frame made only of materials with low thermal conductivity, there is no noticeable difference when heating with electricity, but when the coil is left to cool, the VC does not change when the coil is left to cool. The amount of heat dissipated by conduction and diffusion of heat is small, the coil temperature is difficult to drop, and the cooling time needs to be extended, but as described above, when the winding frame of the present invention is used, there is no need for such a winding.

The present invention is a manufacturing method in which there is little deviation in the temperature distribution of the coil during electrical heating, and the coil temperature decreases in a short time when the coil is removed. Therefore, by carrying out the present invention, it becomes possible to industrially advantageously continuously produce high-quality coils. The present invention will be explained below with reference to Examples. Embodiments 1, 2, 3 For manufacturing horizontal crane-shaped coils for television deflection yokes,
As shown in Figure 1, a base material A made of chrome-plated iron is coated with ceramic (Example 1), Teflon coating (Example 2), aluminum A winding frame prepared by pasting a powder-mixed epoxy resin composite (Example 3) was used, and a wire diameter of 0.4wn having a JISO type structure with a fusion layer made of polyamide and an insulating layer made of polyesterimide was used. The fused electric wire is wound with a coil winding machine to form a coil, heated with electricity to fuse the coil, then formed by pressing, and after cooling,
The coil was removed to produce a deflection coil.

The following table shows the results of tests conducted using conventional methods regarding energization conditions, coil characteristics, coil adhesion, and coil forming workability.

As a comparative example, a conventional winding frame made of iron chrome plating and a winding frame made of an epoxy resin composite material mixed with aluminum powder are used.

Compared to the conventional method, the coil distortion is better when the normal conditions are weak, and when the coil forming workability is very strong, the coil forming workability is the same, but the adhesiveness is excellent. I understand that.

Judgment criteria 1. The coil strain represents the degree of deformation of the coil released from the coil winding frame from the standard coil shape, and those with a large amount of deformation were considered unacceptable, and those with a small amount of deformation were evaluated as excellent.

2. For damage to the coil, a pressure test was conducted on the coil, and those that caused layer shortening were considered to be found, while those that passed the test were judged as non-existent.

3. Adhesiveness Regarding the adhesion state of the fused wire in the part of the coil where the wire distribution density is low, those with large wire dislocation were evaluated as poor, and those with no dislocation were evaluated as excellent.

4. The releasability of the coil represents the degree of difficulty in removing the coil from the winding frame after molding, with difficult ones being rated as poor and easy ones being rated excellent.

5. The coil cooling time represents the press molding time in which the coil distortion is good, and the shorter the coil cooling time, the better the molding workability is.

6. The strength of the current heating condition was determined by increasing the amount of current applied by 30% of the weak condition.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view perpendicular to the coil wire of one example of a winding frame around which a coil is wound (related to a horizontal horn-shaped coil for a television deflection yoke). A... Frame made of chrome-plated iron base material, B... A frame made of a material with low thermal conductivity, 1... Part of the coil with a high wire distribution density, 2... A portion of the coil with a low wire distribution density part.

Claims (1)

[Claims] 1. When manufacturing a coil using the current heating method, which involves winding self-fusing insulated wire around a winding frame to form a coil, fusing the coil by current heating, cooling the coil, and removing the coil, the wire distribution in the coil is determined. The surface of the winding frame material with high thermal conductivity is in contact with the high-density area, and the surface of the winding frame material with low thermal conductivity is in contact with the area with low wire distribution density of the coil, so that it is partially thermally conductive. 1. A method of manufacturing a self-supporting coil, characterized in that a winding frame having a material surface with different surface characteristics is used.