JPH0322513A - Manufacture of resin-molded coil - Google Patents

Abstract

PURPOSE:To complete work by conducting a casting and hardening operation and unnecessitate a polishing work to attain the standard of the edge face of a coil by a method wherein, after an insulating material has been arranged on the inner and outer circumferences of a coil body, molding resin is injected on one edge face of the coil body, it is covered with a material having poor wetting property with the molding resin, and then the molded resin is inverted and hardened. CONSTITUTION:A sheet of glass cloth, in which semihardened epoxy resin is impregnated, is arranged on the side adjoining to the abovementioned molding resin, and an inner peripheral insulating material l and an outer peripheral insulating material 3 are formed by laminating a glass cloth single unit, in which semicured epoxy resin is impregnated, or a polyethylene telephthalate film (PET film). A coil winding 2 is composed of a conductor consisting of wire or sheet of foil of aluminum or copper, and the interlayer insulating material such as a PET film and the like. As the resin used when the first coil end part is molded, the material formed by mixing the fillers such as silica and the like of about 65 to 70wt.% into the basic resin composition and also by mixing colloidal silica therein in order togive thixotropic property, is used. After molding resin has been injected on the edge face of the coil 2, the layer which has poor wetting property with the molding resin 5, is covered by a material 8 which is formed on the surface contacting to the molding resin 8, the molding resin is inverted and hardened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing resin molded coils such as molded transformers.

Conventional technology The conventional method of manufacturing a molded coil is to arrange an insulating material on the inner and outer peripheral surfaces of a coil body made of interlayer insulating material and a conductor, then place it in a mold and inject molding resin. Another method includes disposing an insulating material on the inner and outer circumferential surfaces of the coil body, and then filling the ends of the coil with molding resin.

A partially cutaway perspective view of a molded coil manufactured using the latter method is shown in FIG. Further, FIG. 2 shows a cross-sectional view of a state in which the coil is housed in the mold and filled with molding resin.

In FIGS. 2 and 3, an inner insulating material 11 and an outer insulating material 13 are provided on the inner and outer peripheries of the coil body 12, and after being stored in a molding die 16, resin molding is performed to form a mold resin layer 15. do.

The conventional method of disposing insulating materials 11 and 13 on the inner and outer peripheries of the coil body 12 and molding the ends of the coil with resin is such that when one end surface (the end surface with no exposed wire) is molded first, the resin is To prevent leakage, seal large gaps on the end faces of the coil.

After that, the resin is injected and hardened, and then the coil body 12
By impregnating the coil, the lowered BA fat level is extracted and the end face of the coil is leveled. Next, flip the coil and inject the resin.
After curing, the resin surface B is replenished by impregnating the coil body 12 to compensate for the decrease in the resin surface, and the end surfaces of the coil are leveled by curing.

Problems to be Solved by the Invention However, in the conventional manufacturing method described above, a large amount of resin is required in the case of the mold method, and furthermore, it is difficult to level the upper end surface of the coil and adjust the coil height during casting. The final step, which may be difficult, requires polishing the end face of the coil. In addition, man-hours are required for removing and installing the mold and for maintenance.

In addition, in the conventional end face molding method, large gaps need to be padded to prevent resin leakage during the first molding process, and it takes 2 hours to mold one end face of the coil.
A total of four mold operations are required.

Means for Solving the Problems In order to solve the above problems, the method for manufacturing a resin monoled coil of the present invention includes disposing an insulating material on the inner and outer peripheries of the coil body, and forming a coil end surface where the lead wire is not exposed. After injecting the mold resin into the mold resin, cover the surface with a material that has at least a layer of poor wettability with the mold resin, turn it over, then harden it, and then cover the mold resin on the side where the lead wire is exposed. This is a method in which molding resin is injected into the edge and hardened.

Function: According to the method for manufacturing a resin molded coil described above, after injecting mold resin into the end face of the coil, the coil is covered with a material in which a layer having poor wettability with the mold resin is formed at least on the surface in contact with the mold resin, and the coil is inverted. Since it is cured, the Morolled resin will not leak into the gap between the inner insulating material button of the coil, the outer insulating material, and the lid.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1a is a schematic perspective view of a molded coil manufactured by a method according to an embodiment of the present invention.

5./ FIG. 1b is a partially cutaway perspective view of a coil in which molding resin is injected into the upper end of the coil by the molded coil manufacturing method according to the present invention. In the figure, reference numeral 1 denotes an inner circumferential insulating material, such as a single piece of glass cloth impregnated with semi-hardened epoxy resin, or a material in which a polyethylene terephthalate film (PIT film) is laminated to the above material. What is important here is that high adhesion between the molding resin and the inner circumferential insulating material 1 and the similar outer circumferential insulating material 3 is maintained.

Therefore, when the insulating material is bonded and used, a glass cloth impregnated with a semi-cured epoxy resin is placed on the side in contact with the mold resin.

2 is a coil body composed of a conductor made of aluminum or copper wire 1 or foil, and an interlayer insulating material such as PET film. 4 is a rising wire (plate) made of aluminum or copper. 5 is a molding resin, and the resin used when molding the first end of the coil is a basic resin composition mixed with a filler such as silica of about 65 to 70 wt%, and 0.5 wt% to give chicken tropic properties. Mixed with 1~2wt% colloidal silica? By using a material containing /\-, it is more advantageous to prevent resin leakage during curing.

FIG. 1C shows a state in which the lid is turned over after being covered with a material that has poor wettability with the mold resin. Furthermore, an enlarged sectional view showing an example of a material with poor wettability is shown in FIG. 1d.

In the figure, 6 is a support material such as an iron plate, an aluminum plate, or a stainless steel plate, 7 is a cushioning material such as rubber or felt, and 8 is a material with excellent peelability that has poor wettability with resin, such as Teflon sheet or silicone. Consists of rubber sheet and python sheet.

It is also possible to use this material by directly forming a Teflon film or a silicon release layer on the supporting material 6. Their use is determined by the viscosity and thixotopic properties of the mold fat.

Effects of the Invention As described above, the present invention provides an insulating material on the inner and outer peripheries of a coil body, and then injecting a molding resin into one end surface of the coil (the side where the lead wire is not exposed). After covering the lid with a material that has poor wettability, it is inverted and cured, so the work is completed with a single casting and curing operation, and polishing work is required to level the end face of the coil. do not. Furthermore, the amount of molding resin used is smaller than in conventional molding methods.

[Brief explanation of the drawing]

FIG. 1a is a schematic perspective view of a molded coil produced by a manufacturing method according to an embodiment of the present invention, FIGS.
Figure d is a schematic cross-sectional view of the lid used in the same manufacturing method, Figure 2 is a cross-sectional view of the main part of a molded coil manufactured by the conventional manufacturing method, and Figure 3 is a schematic cross-sectional view of the lid used in the same manufacturing method.
The figure is a partially cutaway perspective view of the same molded coil. 1... Inner circumference insulating material, 2... Coil body, 3... Outer circumference insulating material, 4... Standing wire (plate), 5...
- Mold resin, 6... Support material, 7... Buffer material, 8... Material with excellent resin removability.

Claims (1)

[Claims] a coil body made of an interlayer insulating material and a conductor; a first insulating layer on the inside of the coil body whose surface in contact with the molding resin is made of a semi-cured sheet material; and on the outer periphery of the coil body and in contact with the molding resin. a second insulating layer whose contacting surface is made of a semi-cured sheet material, and after injecting a molding resin into the end face portion of the coil where the lead wire of the coil is not exposed, the second insulating layer has poor wettability with the molding resin; A resin mold characterized by covering the material with a layer formed on its surface, inverting it, then curing it, and then injecting molding resin into the end of the side where the lead line is exposed and curing it. How to manufacture coils.