JPS58202506A - Resin-molded coil - Google Patents

Abstract

PURPOSE:To reduce tandelta and eliminate insulation defects due to voids, by forming upper and lower end insulators from a material excellent in resin impregnation properties, and impregnating a hardening accelerator only into a glass- cloth tape and the lower end insulator. CONSTITUTION:A bobbin 1 is wound with a secondary winding 2, and a lead 2' of the winding 2 is upwardly led out. Then, the outer periphery of the winding 2 is wound with a glass-cloth tape 3 impregnated with a hardening accelerator. A corrugated space insulator 4 is disposed and wound with the tape 3, which is then wound with a primary winding 5. Then, insulators 7, 8 are disposed at the upper and lower ends of the windings 5, 2, and only the lower-end insulator 8 is impregnated with a hardening accelerator. An interlayer insulator 6 is disposed between the layers of the primary winding 5, and the outermost periphery is wound with the tape 3. The upper end of the insulator 6 is inserted between the parts of the insulator 7 and exposed on the coil upper part surface, while the lower end of the insulator 6 is folded between the layers of the windings 5 so as not to be exposed on the coil lower part surface.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an impregnated type used in, for example, a dry type transformer. m
Regarding a 1m molded coil.

[Technical background of the invention and its problems]

In the field of dry type transformers, molded transformers in which the entire coil is molded with synthetic resin have appeared, and due to their excellent features such as compactness and flammability, they have become the mainstream of small transformers. .

There are 12 methods for manufacturing resin molded transformers: a mold type in which the entire coil is set in a mold and resin is injected and hardened, and an impregnated type in which the entire coil is impregnated with resin and then taken out and hardened. However, since the latter uses a resin with a lower viscosity than the former C, the impregnation of the resin into the coil is better, and a molded transformer with excellent insulation and heat resistance can be obtained. Since no excess resin adheres, no cracks occur, and the device can be made smaller and lighter.

Conventional methods for manufacturing this impregnation type include: (1) After taking the coil out of the impregnation tank, the coil is placed in a rotation drive device and hot air is blown in while rotating to harden the coil. ■
The inside of the coil or the coil insulation layer is impregnated with a curing accelerator in advance, and then impregnated with C resin.The curing accelerator and resin react to form a gel, and the resin leaks out of the coil.When the force is reached, the coil is closed. A method in which the material is taken out of the impregnation tank and cured in a heating furnace. Two methods are known, but method (2) is not suitable for mass-produced models due to equipment limitations of the rotary drive device, so method (2) is attracting attention.

1 is a plan view of a resin molded coil obtained by the method (2) above, and FIG. 2 is a detailed sectional view of FIG. 1.

As shown in the figure, the secondary winding 2 is wound around the C2 winding frame 1, and after the lead wire is pulled out upwardly, a glass cloth tape 3 is wound around the outer periphery of the secondary winding 2 to form an outer periphery insulating layer. Further i
n The outer side C2 is provided with a spacing insulator 4 to maintain insulation between the primary winding 5 and the secondary winding 2, and the primary winding 5 is wound through the glass cloth tape 3 on the outside I. , the lead wire 5' is pulled out above the coil. Thereafter, in the same manner, @green is wound through the interwave insulator 6 to form a coil.

End wire breakers 7.8 are provided at the upper and lower ends of the winding to insulate the coil and improve its mechanical strength. The interstage insulator 6ii passes through the end insulators 7 and 8 to the coil surface.

The entire 62-wound coil is impregnated in advance with a hardening accelerator solution, placed in a resin impregnation tank, and left as it is at a humidity that promotes gelation. After the resin gels and the resin inside the coil does not leak out, the coil is pulled up from the impregnating bath and hardened in a dryer to produce a resin molded coil.

By the way, Figure 3 shows the accuracy of the solution when an ethyl alcohol solution of IB2uz (hardening accelerator manufactured by Shikoku Kasei Co., Ltd.: trade name) of imidazole yarn is used as a hardening accelerator, and the interlayer after resin impregnation and hardening. This graph shows the relationship between tan δ and temperature characteristics.As the concentration of the curing accelerator solution increases (thus, tana increases). It is meant to reduce the insulation properties of the layer.It was also found that the hardening accelerator also reduces the heat-generating properties.Furthermore, when soaking in the curing accelerator solution C Nicoil, the inner and outer peripheries There is also the disadvantage that the glass tape that is wound is loosely wrapped (X7), making it impossible to maintain its original state.Furthermore, as the coil becomes larger, a large amount of curing accelerator is required, which increases costs. 01fc, which is the cause, is that the upper and lower ends, inner periphery, and outer periphery of the coil are covered with an insulating layer impregnated with a curing accelerator, so if this part gels before the resin is impregnated with light, the resin will no longer be used. could not be impregnated into the inside of the coil, and voids were formed inside the coil due to the subsequent curing and shrinkage of the resin, resulting in partial discharge when electrical stress was applied, which was unfavorable in terms of reliability. .

[Purpose of the invention]

The present invention overcomes the above-mentioned drawbacks, and its purpose is to
A molded coil with a small anδ and no insulation defects such as voids [Summary of the Invention] The present invention has been made to achieve the above object, Winding interlayer 1: ff(
An interstage insulator with good oil impregnation properties is inserted, and Niglass cloth tape is wound around the inner and outer circumferences of the electric winding, and upper end insulators and upper end insulators are placed at the upper and lower ends of the electric winding, respectively. One unit of resin molded coil is made by impregnating and hardening a synthetic resin into a coil provided with an insulator, and the upper and upper end insulators are made of a material with good resin impregnability, and the glass cloth tape and the upper end insulator are made of a material with good resin impregnation properties. The insulator is C2-shaped so that its upper end is exposed to the upper surface of the coil and its lower end does not reach the lower side of the coil. The material for the upper and upper end insulators is preferably one that is easily impregnated with resin, such as aromatic polyamide nonwoven fabric, asbestos mineral fiber board, glass cloth tape, or the like.

[Embodiments of the invention]

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

FIG. 4 is a partial sectional view of the resin molded coil of the present invention, and FIG. 5 is an enlarged view of the lower end of the coil. After winding the secondary winding 2 around the winding frame I and pulling out the lead wire 2' upward, the outer circumference of the secondary winding 2 is wound with Nikarasu cloth tape 3. This glass cloth tape 3 is pre-impregnated with a curing accelerator. Next, a wave-shaped spacing insulator 4 is placed,
A crow cloth tape 3 impregnated with a curing accelerator is wound around the outer periphery, and the next winding 5 of the missing number is wound. - The upper and lower ends In of the secondary i-wire 5 and the secondary winding 2 are each provided with an end insulator 7
．． Place 8. The upper and lower end insulators 7.8 are made of a material with good resin impregnation properties, such as aromatic polyamide nonwoven fabric (e.g. Nippon Vilene HHa5408), asbestos, mineral fiber board (product name: M Tosheet), etc. used. Among the upper and lower end insulators, only the lower end insulator 8 is impregnated with a curing accelerator.
□], j A crotch insulator 6 is placed between the layers C of the knee winding, and a glass cloth tape 3 treated with a curing accelerator is wound around the outermost circumference of the -th order winding. The upper end of the crotch insulator 6ii is inserted between the upper end insulators 7 and protrudes from the upper surface of the coil as shown in Figure 5. As shown in Figure 2, the lower end is completely bent between the wire 8 and the primary winding 5, so that the lower surface of the coil τ2 is not exposed. Stretch out the lower part of the coil (length ζ− without double rows)
The coil thus constructed can be immersed in the impregnated resin bath 5 to impregnate the entire coil with resin. The temperature of the impregnated resin at this time is set to a temperature suitable for unrolling the part treated with the curing accelerator. One coil is left in the impregnating tank, and when the gelation of the treated area has progressed to a point where the resin impregnated into the coil does not leak, the coil is removed from the soaking tank. Next f2,
This coil is placed in a heating furnace and the impregnated resin is completely cured to obtain a resin molded coil.

In this example, an epoxy resin acid anhydride system such as EP 828 (trade name manufactured by Shell Chemical Co., Ltd.) and 1mN-2200 (trade name manufactured by Hitachi Chemical Co., Ltd.) was used as the impregnating resin, and IB2MZ:ethyl was used as the curing accelerator. Alcohol =
A 10:90 solution was used. In the curing accelerator treatment, the object to be treated was immersed in the solution for 21 minutes and then dried to evaporate the ethyl alcohol solvent. The resin impregnation treatment was carried out by leaving the sample in the impregnated resin at 80 to 90 DEG C. for 1 hour, and as a result, the hardening accelerator-treated area gelled, and its sealing effect was exhibited in light.

〔Effect of the invention〕

As explained above, in the resin molded coil of the present invention, the lower end insulator and the glass cloth tapes on the inner and outer peripheries of the winding are pretreated with a curing accelerator. The curing reaction of the part progresses, resulting in gelation or hardening. Therefore, the coil is in the state 1 when the bottom and surroundings are closed, and the uncured resin impregnated inside the coil is also in the state 1 when the coil is pulled up or while it is hardening in the heating furnace.
-No leakage and no insulation defects such as voids due to resin dripping.

Further, since the upper insulator is not treated with a curing accelerator, it does not interact with the seal layer 12, and since the upper insulator and the interstage insulator are impregnated with resin, the resin is sufficiently impregnated into the coil. L7 Therefore, defects such as voids due to non-resin impregnation are not formed.

Further, since the lower end of the crotch insulator does not reach the surface of the coil, the resin inside the coil does not leak out through the crotch insulator. Since the curing accelerator is impregnated only into the glass cloth tape and the lower end insulator, the phenomenon of increase in tanJ does not occur. It has excellent insulating properties, with no loss of heat and low tanJ.

[Brief explanation of drawings]

Figures 1 and 2 are a plan view and a partial sectional view of a conventional resin molded coil, Figure 3 is a graph showing the relationship between curing accelerator solution, temperature characteristics of # degree and tanJ, and Figure 4 is a graph showing the relationship between temperature characteristics of the hardening accelerator solution and tanJ. 5 and 6 are respectively an enlarged view of the upper end and an enlarged lower end of the resin molded coil of the present invention. 1... Winding frame 2... Secondary winding 2'...
Secondary winding lead wire 3... Glass cloth tape 4... Spacing insulator 5.
...-Next winding 5'...-Next winding lead wire 6.
...Interstage insulator 7...Top end insulator 8...Lower end insulator (8733) Representative patent attorney Yoshiaki Inomata (and 1 others)
(11) Figure 1 Figure 3 Figure 4 2'5' /=27 1 ■ 13 Figure 5 Figure 6

Claims (2)

[Claims] (1) Interlayer I between the winding frame, the next electric winding that is wound 62 times on the winding frame, and the station electric winding: The inserted crotch insulator with good resin impregnation and the inside of the electric winding. A coil consisting of a glass cloth tape wound around the circumference and the outer circumference, and an upper end insulator and an upper end insulator disposed at the upper end and lower end of the electrical winding, respectively, is impregnated and hardened with a synthetic resin. In the resin-molded coil, the upper and upper end insulators are made of a material with good resin impregnation, only the glass cloth tape and the upper end insulator are impregnated with a curing accelerator, and the interstage insulator is impregnated with a curing accelerator. whose upper end is the upper surface of the coil (
A resin molded coil characterized in that the lower end portion is exposed and is not connected to the lower surface of the coil. (2) Claim 1, in which the upper end insulator is formed of polyamide nonwoven fabric, asbestos mineral fiber board, or glass cloth tape! Resin molded coil described in J.