JPS59129414A - Manufacture of resin molded coil - Google Patents

Abstract

PURPOSE:To obtain a resin sealed coil having no insulation defect in its cooling air passage by such an arrangement wherein an insulation board which is treated by a hardening accelerator and excellent in impregnating resin is provided inside and outside a cooling air passage between an inner and outer coil, or between wound layers, and the outermost wound layer is wrapped around with a tape treated by a hardening accelerator, and the coil unit is impregnated with resin. CONSTITUTION:A low voltage coil 2 is provided on a winding frame 1, a lead wire 2b is drawn out, and an asbestos board 10 treated by a hardening accelerator is provided around the coil 2, and a cooling air passage is formed by a space insulator 4 and a board 11 similar to the board 10 is provided. Around the coil, a coil 5 is wound, and a high voltage coil is completed by placing an insulator 6 between layers and a glass tape 3 treated by a hardening accelerator is wrapped around it. Outside the upper and lower ends of wound layers of the coils 2, 5, asbestos is arranged as conventionally. After the hardening accelerator adhere to the lower end of the coil of this composition, resin is caused to impregnate under vacuum and it is dried, and by this, the resin is gelled and it prevents resin not hardened yet from the leaking and the generation of an area not impregnated and a cooling air passage is also formed nicely, and a resin sealed coil excellent in cooling capacity can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical outline of the invention] The present invention relates to a method for manufacturing a resin molded coil of impregnated tights used in electromagnetic induction equipment such as dry transformers and reactors.

[Technical background of the invention and its problems]

Recently, in the field of dry type transformers, molded dry type transformers have appeared, which are made by impregnating and hardening resin to improve insulation properties. This molded dry type transformer is generally constructed by arranging resin-molded coils concentrically around an iron core cape.

There are two main methods for manufacturing the coils used in molded dry transformers: methods that use molds and methods that do not. For this reason, the so-called impregnation type method of manufacturing resin molded coils without using a mold is increasing. In the case of impregnated tights, there is no extra resin layer attached, so there is no cracking that is typical of molded coils, and the product can be made smaller and lighter.

Furthermore, since a low viscosity resin can be used, the resin is well impregnated into the coil, the heat resistance and insulation properties of the resin are effectively exhibited, and a highly reliable resin molded coil can be obtained. However, since a low viscosity resin is used and no mold is used, there is a risk that the resin impregnated into the coil may leak out, and the key to this manufacturing method is how to prevent this.

The conventional impregnation type manufacturing method is as follows: (1) A coil impregnated with resin is taken out from a resin impregnation tank, and then the coil is rotated by a rotation drive device.
A method of curing the resin by heating the coil. (2) A curing accelerator is attached in advance to the inside of the coil or to the coil insulation layer, and the curing accelerator is impregnated with the resin. The curing accelerator and resin react to form a keloid. A known method is to take the coil out of the resin impregnation tank once the resin has stopped leaking and to cure the resin in a heating furnace. Of these, regarding method (1),
It requires work to connect the coil to a rotary drive device, and due to the equipment limitations of the rotary drive device, it has the drawback of not being suitable for mass production, and in recent years, manufacturing method (2) has been attracting attention. Ta.

This manufacturing method (2) will be explained with reference to the drawings.

FIGS. 1 and 2 show an example of a resin molded coil produced by a conventional manufacturing method.

To manufacture a resin molded coil by this conventional method, the conductor 2a is wound on a winding frame to form the inner coil 2, the lead wire 2b is drawn upward, and the outer periphery is impregnated with a curing accelerator. The outer insulating layer 3 is formed by winding the hoop tape. A spacer insulator 4 is provided on the outside of the outer peripheral insulator layer 3.
Place. A glass tape to which a curing accelerator has been applied in advance is wound on the outside of this spacer insulator 4 to form an insulating layer 3, and then a conductor 5a is wound to form an outer coil 5, and the lead wire 5b is passed above the coil. Pull out. The outer coil 5 is formed of a plurality of conductor winding layers with an interstage insulator 6 in between.

Additionally, end insulators 7 are provided outside the upper and lower ends of the conductor-wound layer of each coil 2.5 in order to insulate the coil and improve mechanical strength, and this end insulator 7 is also treated with a hardening accelerator. I'll keep it. Further, the outer circumferential surface of the outer coil 5 was also treated with a curing accelerator, and an insulating layer 3 was formed using lath tape. In this way, the insulating layer 3 and end insulator 7 located on the outer surface of the coil are treated with a curing accelerator in advance, and the entire coil is impregnated with resin in an impregnating bath (not shown), and then left as is at a predetermined temperature. do. Then, the resin impregnated into the insulating layer 3 and the end insulator 7 reacts with the hardening accelerator and becomes dull, and even when the coil is taken out of the impregnation tank, the resin impregnated into the coil is blocked by the dulled insulating layer 3, etc. Let it harden until it no longer drips.

At that point, the coil was taken out of the impregnation tank and heated in a heating furnace to harden the resin to obtain a resin-molded coil.

However, the following drawbacks were found in this conventional manufacturing method. That is, in FIG. 1, the outer insulating layer 3 of the spacer insulator 4 falls between the wave pitches of the spacer insulator 4, and although not shown in FIG. 1, a gap is created between it and the outer coil 5. When the viscosity of the resin to be impregnated is low, a void or a zide is formed between the outer coil 5 and the insulating layer 3, causing partial discharge in this portion, resulting in a low dielectric breakdown voltage. In this case, it is possible to increase the viscosity of the resin so that the surface tension of the resin holds the resin in the voids in the kernel part, but then this part becomes resin-rich.
Cracks occur and cause partial discharge, which not only leads to a drop in the voltage across the insulating layer and across, but also causes excess resin to adhere to the cooling airways, narrowing the gap between the cooling airways and deteriorating the cooling effect. There were drawbacks.

In order to prevent this depression of the cooling airway portion, there is a method of reducing the pitch of the 40 waves of spaced insulators, but this method has drawbacks such as sacrificing cooling efficiency and increasing the coil size and weight.

[Object of the invention] The present invention has been made to eliminate the above-mentioned drawbacks.
To provide an economical method for manufacturing a resin molded coil that does not cause insulation defects in the portion facing the cooling airway, secures a cooling airway of a predetermined size, and does not impair cooling characteristics. With the goal.

[Summary of the invention]

To achieve this purpose, on the inner and outer peripheries of the cooling airways formed between the inner and outer coils or between the conductor winding layers,
An insulating boat made of a material with good resin impregnation properties and treated with a curing accelerator is provided, and a coil is provided with an outer insulating layer treated with a curing accelerator on the outside of the outermost winding layer. After treating the insulator with a curing accelerator, it is impregnated with resin in an impregnating bath to insulate it. - When the resin impregnated into the outer circumferential insulating layer and the lower end insulating material reacts with the curing accelerator and becomes rubberized, the coil is removed from the impregnation tank and heated to harden the resin. .

[Embodiments of the invention]

The method for manufacturing a resin molded coil according to the present invention will be described below with reference to FIGS. 3 to 5.

Figures 3 and 4 show an example of a cylindrical fill, in which a conductor 2& is wound on a winding frame 1 to form an inner (low voltage) coil 2 having at least one winding layer, and a lead wire 2b is directed upward. Pull it out. The outer periphery of the inner coil 2 is coated with an aromatic polyamide (trade name: HA, l- #-de, made by Nippon Aroma),
Provide an insulating g-pyo made of asbestos or mineral fiber.

For example, imidazole IB2MZ (?
Insulation is applied to the plate 9 by impregnating it with a solution prepared by dissolving 1:1 in ethyl alcohol (general rule), and then drying it. Next, this insulation, j? - A corrugated spacing insulator 4 is arranged around the outer periphery of the door 10 to form a cooling airway.

The outer periphery of this spaced insulator 4 is an insulator treated with a curing accelerator in the same manner as described above. - Provide a do 1 no. A conductor 5a is wound around the outer periphery of the conductor 5a, and a plurality of the wound layers are provided via an interlayer insulator 6 to form an outer (high voltage) coil 5, and a lead wire 5b is formed.
bring out. The outer circumferential insulating layer 3 is formed by winding a high-strength fiber material such as glass tenor, which has been treated with a curing accelerator, around the outer periphery of the outer coil 5 to a required thickness.

End insulators 7, 2 are disposed outside the upper and lower ends of each of the winding layers of the inner and outer coils 2, 5, as in the prior art. These end insulators 7, 7 are made of a material that is well impregnated with resin. - For example, aromatic polyamide nonwoven fabric (Nippon Vilene HC)
5408), aromatic polyamide felt (Nippon Vilene gHP-121), asbestos, rock wool, etc. can be used.

The lower end of the coil thus formed was coated with imidazole I
The curing accelerator, such as B2MZ or 2E4MZ, is immersed in a solution of a solvent such as ethyl alcohol or water to adhere the curing accelerator to the lower end of the coil insulator 7 and the interlayer insulator 6, and then the coil Dry the solvent and evaporate the water. Next, this coil is placed in an impregnating bath (not shown) kept under vacuum with a low viscosity resin (for example, acid anhydride epoxy resin EP82).
8. Impregnate with hardening agent HN2200, etc.). After injection of the resin is completed, pressure is applied to further impregnate the inside of the coil 9-. After that, insulation boat 1θ.

The resin impregnated into the coil 1, the upper end insulator 7, etc. reacts with the curing accelerator to form a resin, and is cured until the resin impregnated into the coil no longer leaks even when the coil is removed from the impregnation tank. At that point, the coil is taken out of the impregnating tank, placed in a heating furnace (not shown), and heated to harden the resin, thereby obtaining a resin molded coil.

In this way, in the present invention, the resin impregnated into the insulating dates 10 and 11, the outer peripheral insulating layer 3, and the lower end of the coil, which have been treated with a curing accelerator in advance, reacts with the curing accelerator to form a seal layer. do. Therefore, the inner coil 2 is in the state of a container in which the bottom, inner and outer circumferences are closed by the wire 10 and the upper end insulator 7, etc., and the outer coil 5 is not insulated. - Since the bottom, inner and outer periphery of the coil are blocked by the outer insulating layer 3, upper end insulating layer 7, etc., the uncured resin inside the coil is 10- No leakage during curing in a heating furnace. Therefore, since there is no resin-unimpregnated portion in each coil 2, 5, the insulation performance of the coil can be improved, and heat transfer is improved, so that cooling performance can be improved. Moreover, the resin is not only passed through the end insulators 7, 7, but also the insulation made of a material with good resin impregnation properties.
Since it can be impregnated through the wires 10 and 11 and the outer peripheral insulating layer 3, the inside of the coil can be impregnated in a short time.

On the other hand, since the bottom of the cooling airway portion is not blocked, the resin flows down when the coil is pulled up from the impregnation tank, and after the coil is heated and hardened, the size of the cooling airway is maintained as designed. In particular, in the method of the present invention, since a low-viscosity resin can be used as the resin, excess resin easily falls off, and there is no possibility of forming resin pools that can cause cracks in the cooling airways and on the inner and outer circumferential surfaces of the coil. Also, the insulation is
There is no drop into the cooling airway, and each coil 2, 5
There is no risk of forming a resin-rich portion between the insulating board 10° and the insulating board 10°, or blocking the cooling airway. Therefore, since a cooling airway of a predetermined size can be secured, cooling performance is not impaired.

Although the above embodiment has been described with reference to the case where there is a cooling airway between the inner and outer coils 2 and 5, it is also possible to implement the case where there is a cooling airway between the winding layers of each coil 2.5. That is, when the outer coil 5 is composed of four winding layers as shown in FIG. Insulating boards 1θ and 1no may be provided on the inner and outer peripheries of the airway. In this case, the inner periphery of the first winding layer is made of a material with poor resin permeability, such as glass-mixed polyamide. - An insulating layer 3a made of a high-strength fiber material treated with a hardening accelerator is provided.

In addition, the insulating layer provided around the outer circumference of the outermost wound layer is not only an insulating layer 3a made of a high-strength fiber material, but also an insulating layer 3b made of a material with poor resin permeability is interposed in the middle to improve the sealing effect of the resin. do.

Furthermore, the spacing insulator 4 is not limited to a wave-shaped one, and can also be constructed by arranging insulating rods at intervals in the circumferential direction.

〔Effect of the invention〕

As explained above, according to the manufacturing method of the present invention, it is possible to impregnate the inside of the coil with a low-viscosity resin, and since the resin does not leak outside during the curing process, the insulating layer inside the coil is not left untreated. A resin molded coil with excellent insulation performance can be obtained without forming an impregnated part. In addition, since there is no excess resin attached to the cooling airway, the size of the design can be ensured. Also, there is no unimpregnated part inside the coil, so heat transfer is good9, and the resin molded coil has excellent cooling. Obtainable.

On the other hand, since there is no need for special equipment such as a rotary drive device or a mold, there are great economic effects such as simplification of the manufacturing process and time reduction.

[Brief explanation of drawings]

1 and 2 are a plan view and a partial sectional view of a resin-molded coil manufactured by a conventional manufacturing method, and FIGS. 3 and 4 are a plan view and a partial sectional view of a resin-molded coil manufactured by the manufacturing method of the present invention. 5 are sectional views showing main parts according to another embodiment of the present invention. 1... winding frame, 2... inner coil, 2&... conductor,
3... Insulating layer, 4... Spacing insulator, 5... Outer coil, 6... Interlayer insulator, 7... End insulator, 10
．． 11...Insulation board. Applicant's agent Patent attorney Takehiko Suzue 14- Figure 1, 2nd flash, 3rd WJ Figure 4, h t=L

Claims (1)

[Claims] End insulators are provided outside the upper and lower ends of the winding layer in which the conductor is wound, and the inner and outer peripheries of the cooling airways formed between the inner and outer coils or between the winding layers are made of a material that is easily impregnated with resin. A coil is provided with an insulating date that is formed and treated with a curing accelerator, and an outer insulating layer that is treated with a curing accelerator on the outside of the outermost wound layer, and the lower end of the coil is provided with an insulating date that is treated with a curing accelerator. After the application, the coil is impregnated with a resin in an impregnating tank, and when the resin impregnated into the insulating board, the outer peripheral insulating layer, and the lower end insulator reacts with the curing accelerator and becomes a rubber, the coil is impregnated with the impregnated resin. A method of manufacturing a resin molded coil by removing it from a tank and heating it to harden the resin.