JPS6142844B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a donut-shaped coil, and particularly relates to a method for manufacturing a donut-shaped coil, and in particular, a method for manufacturing a donut-shaped coil, in which a wire conductor layer with a relatively large cross-sectional shape and an insulating layer are interposed, which causes collapse and waviness during winding work. This invention relates to a method of manufacturing a donut-shaped coil formed by winding the coil around the coil.

In general, a donut-shaped coil has a core 1 fixed on a coil receiving plate 2, as shown in FIGS. 1 and 2.
The wire conductor 3 is sequentially wound around the wire while inserting the layer insulator 4. In such winding work, the bending accuracy of the wire conductor 3 allows the wire conductor 3 to
slumping and small undulations occur. In the donut-shaped coil, these wire conductors 3 are stacked in the thickness direction, which creates uneven gaps between adjacent wire conductors 3, resulting in areas where the layer insulation 4 is locally pressed. Then, there will be places where there are gaps. As a means of filling these gaps and expanding the bonding area, before inserting the layer insulator 4, the surface of the layer insulator 4 and the outer circumferential surface of the already wound wire conductor 3, as well as the wound surface of the layer insulator 4, are There is a method in which a high viscosity varnish 5a mixed with glass fiber cut into chips is applied to the inner peripheral surface of the wire conductor 3, the wire is inserted, and then the wire conductor 3 is wound.
In this case, as shown in FIG.
The varnish 5b escapes into the gap, and the excess varnish 5b is pushed out and flows onto the coil receiving plate 2 and the already wound wire conductor 3a. The varnish 5b that flowed out was wiped off and then cleaned with a solvent. Furthermore, when a room temperature curing type varnish is used as the varnish 5a, it hardens during the winding process, and the working environment of turning the coil receiving plate twice is better than that of a heat curing type varnish. During curing, there was a concern that peeling would occur between the stranded conductor 3 and the layer insulator 4 due to the difference in thermal expansion between the stranded conductors 3 due to the temperature difference. Furthermore, mechanical problems remain, and therefore heat-curing varnishes are currently used instead of room-temperature-curing varnishes. However, heat-curing varnishes are extremely sticky, not only during cleaning at the time of winding, but also during winding, and a small amount of varnish flows, resulting in continuous cleaning, resulting in poor workability and an enormous number of man-hours. There were such shortcomings.

The present invention has been made in view of the above points, and its purpose is to easily fill the gap between adjacent strand conductors during winding, and to improve workability. The present invention provides a method for manufacturing a donut-shaped coil.

In the present invention, before winding an unwound wire conductor, a prepreg resin film is attached to at least one surface of a layer insulator located between the wire conductor that has already been wound, and the wire conductor is spirally wound. After the first step of spinning, tension is applied in the winding direction of the wire conductor, surface pressure is applied in the winding thickness direction, and the prepreg resin film is softened by heating and holding in this state. a second step in which the material is extruded from a high surface pressure area to a low surface pressure area to obtain fluidity;
By repeating the above steps and the second step to complete all windings, the manufacturing method comprises a third step of heating the wire conductor all at once to soften the prepreg resin film again, and then harden it. , to achieve the desired purpose.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6. That is, the wire conductor 3 is wound around the winding core 1 fixed on the coil receiving plate 2 via the layer insulator 4.
As shown in the figure, before winding the unwound wire conductor 3b, a prepreg resin film 6 such as glass cloth or glass is coated on one or both sides of the layer insulator 4 located between the already wound wire conductor 3a. A prepreg resin film made by impregnating a nonwoven fabric or a polyester nonwoven fabric with a polyester or epoxy resin to make it semi-cured, or a so-called prepreg resin film made by making only the resin into a prepreg, is inserted. Incidentally, this prepreg resin film 6 may be attached to the wire conductor 3 side. This prepreg resin film 6 is the seventh
As shown in the figure, the dimensions rapidly change between 30 and 70℃ when the surface pressure is 0.5 to 3.0Kg/ ^cm2 , and gelation does not progress much when held at 70℃ for 10 hours. It has characteristics. A first step of combining and inserting the prepreg resin film 6, and as shown in FIG. 4, wrapping the wire conductor 3b to be wound, applying tension in the winding direction, and clamping the winding thickness direction. By doing,
Apply a surface pressure of 0.5 to 3.0 Kg/cm ² in the direction of the roll thickness. In addition, the already wound wire conductor 3a and the unwound wire conductor 3b are energized and heated with high frequency, and if the conductor has a cooling pipe, hot water or steam is passed through the prepreg resin. It is heated to 60 to 70°C, which is the optimum temperature based on the properties of the film 6, and held for several minutes. By heating in this way, the prepreg resin film 6 softens and acquires fluidity.
It is pushed out from areas with high surface pressure to areas with low surface pressure, filling the gap. Through this second step and the repetition of the first and second steps, the entire winding operation is completed as shown in Figure 5. Due to the difference in thermal expansion caused by the temperature difference caused by heating, minute gaps 7 are formed between the layer insulator 4 and the wire conductor 3, albeit here and there. However, as shown in FIG. 6, when the wire conductor 3 is heated and hardened all at once after winding, the prepreg resin film 6 softens again and becomes fluid, which occurs in the gap 7. The excess varnish 5b flows in and fills the area, and completely hardens while wetting the surface of the wire conductor 3.
The layers are glued together. By manufacturing the wire using the third step, the varnish does not flow out, cleaning is easy, and the wire conductor can be handled easily. This has the effect of improving workability and greatly reducing the number of work steps.

According to the method of manufacturing a donut-shaped coil of the present invention described above, before winding the unwound wire conductor,
A first step of spirally winding the wire conductor by adding a prepreg resin film to at least one surface of the layer insulator located between the already wound wire conductor, and after the first step, Applying tension in the winding direction of the wire conductor and applying surface pressure in the winding thickness direction,
In this state, the prepreg resin film is heated and held to soften it to obtain fluidity, and a second step is performed in which the prepreg resin film is extruded from a high area to a low area, and the first and second steps are repeated. After all winding is completed,
Since the manufacturing method consists of a third step of heating the wire conductors all at once to soften the prepreg resin film again and then harden it, the prepreg resin film is heated in the second step. It softens and becomes fluid, and since force is applied from both the winding direction and the winding thickness direction of the wire conductor, it is pushed out from areas with high surface pressure to areas with low surface pressure.
You can easily fill the gaps that occur during winding.
In addition, in the third step, after all winding is completed, the whole is heated all at once to remove the fine gaps that occur between the layer insulator and the wire conductor due to the difference in thermal elongation caused by the heating in the second step. By re-softening the resin film, excess varnish comes out fluidly and flows in and buries, and is completely cured while wetting the surface of the wire conductor, so varnish no longer flows out, making cleaning easier and greatly improving work efficiency. This method is very effective when manufacturing this kind of donut-shaped coil.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the winding work of a donut-shaped coil, FIG. 2 is a cross-sectional view taken along the line of FIG. 1 during winding in the conventional method, and FIGS. FIG. 7 is a sectional view showing the winding order of the coil, and a diagram showing the thermopressure characteristics of the prepreg resin film under a surface pressure of 2.0 kg/cm ² . 1... Winding core, 2... Coil receiving plate, 3... Element wire conductor, 4... Layer insulator, 6... Prepreg resin film.

Claims (1)

[Claims] 1. When forming a donut-shaped coil by winding a predetermined number of turns of a wire conductor in a spiral shape with a layer insulator interposed, the unwound wire conductor is wound around a winding core fixed on a coil receiving plate. a first step of winding the wire conductor with a prepreg resin film attached to at least one surface of the layer insulator located between the wire conductor and the wire conductor that has already been wound;
After the process, tension is applied in the winding direction of the wire conductor and surface pressure is applied in the direction of the winding thickness, and heating and holding in this state softens the prepreg resin film to obtain fluidity and reduce the surface pressure. A second process of extruding from a high part to a low part, and the first process and second process are repeated to complete all windings, and then the wire conductor is heated all at once to soften the prepreg resin film again. A method for manufacturing a donut-shaped coil comprising a third step of post-curing.