JPS6265313A - Manufacture of resin molded coil - Google Patents

Abstract

PURPOSE:To prevent the deterioration of impregnated resin due to the elution of a hardening accelerator when a multiplex winding coil is resin-impregnated by a method wherein a hardening accelerator is adhered to the insulating coating of a conductor and the heat-proof board of an end part insulating material only, and the hardening accelerator is not adhered to an interlayer insulating material and the insulating material on the outer circumference. CONSTITUTION:A board 3b, having a high resin impregnating property, composed of a heat-proof board 3a and rock wool is used as an end-part insulating material 3 in assembled form using a hardening accelerator at least on the heat-proof board only of the lower end insulating material 3, and no hardening accelerator treatment is performed on the board 3b having a high sucking property of the hardening accelerator. Accordingly, the generation of so-called migrating phenomenon of the hardening accelerator, wherein the hardening accelerator adhered to the material elutes in the course of the resin impregnating treatment, is reduced and the resin can be maintained at a fixed viscosity, because no deterioration of impregnated resin is generated. Besides, as the board 3b is compressed by pressing the board 3a from both sides by pinching it from the inner and the outer circumferences of the board 3b, no resin leak is generated on the part above-mentioned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing resin molded coils used in high voltage, large capacity molded dry transformers, reactors, and the like.

[Technical background of the invention and its problems] There are two main methods for manufacturing coils used in molded dry ovens: methods that use molds and methods that do not use molds. The method of manufacturing resin molded coils without using a mold is increasing because it has advantages in terms of productivity such as maintenance and economy. As one method that does not use this mold,
As described in the above publication, there is a method in which an insulating layer is formed by attaching a curing accelerator to an insulator in advance and reacting it with a resin, and this method has the advantage that the resin treatment step can be performed in a cylindrical manner.

When manufacturing a resin molded coil by this method, first, a plurality of conductor winding layers each formed by winding a conductor are wound concentrically around an insulating cylinder with an interlayer insulator interposed therebetween.
A multi-wound coil is formed by providing end insulators at the upper and lower ends of each conductor-wound layer, and by providing an outer peripheral insulator at the outermost periphery of the conductor-wound layer. A curing accelerator is applied to the upper end insulator, the outer circumferential insulator, and, if necessary, the interlayer insulator in this multi-wound coil. Then, this multi-wound coil is placed in a resin bath and impregnated with resin. When the impregnated resin reacts with the curing accelerator and becomes a gel, the multi-wound coil is taken out, and then the impregnated resin is heated and cured to form a resin molded coil. Manufacture.

In this method of manufacturing a resin molded coil, the end insulator is a nonwoven fabric to which a curing accelerator has been applied in advance;
A sheet-like insulator such as rock wool that is easily impregnated with resin is used. When such a material is used, during the resin impregnation treatment of the coil, a portion of the curing accelerator that has been attached to the end insulator in advance is leached into the impregnated resin, shortening the pot life of the impregnated resin. For this reason, when the impregnated resin is used repeatedly, it becomes very difficult to adjust the viscosity of the impregnated resin, resulting in poor resin yield. In particular, when non-woven fabrics, rock wool, etc. are impregnated with resin, the curing accelerator content increases dramatically, so that the tendency to thicken due to dissolution is more likely to occur. In addition, rock wool has the disadvantage that mechanical strength such as tensile properties decreases when treated with a curing accelerator, so when winding a coil, the rock wool may break when used as an end insulator, making work extremely difficult. It gets worse.

In addition, since materials that are easily impregnated with resin, such as non-woven fabric and rock wool, do not have good mechanical properties such as compressive strength, the end insulation may lose its shape during handling such as transporting the coil until it is impregnated with resin. This may lead to resin leakage and insulation defects.

[Object of the Invention] In order to solve the above-mentioned problems, an object of the present invention is to provide a method for manufacturing a resin molded coil having a multi-wound structure that has excellent impregnability and good quality.

[Summary of the invention] The method for manufacturing a resin molded coil according to the present invention involves winding a conductor having an insulating coating that is easily impregnated with resin into a cylindrical shape, and providing end insulators on the outside of the upper and lower ends of the conductor-wound layer. When forming a multi-wound coil by providing multiple layers concentrically with interlayer insulators in between, a heat-resistant board with good resin impregnation and a board with a thick resin content are used as the end insulator in combination. At the same time, a curing accelerator is attached only to the heat-resistant board of the insulator at least at the upper end and the insulating coating of the conductor, and then the multi-wound coil is placed in a resin bath and impregnated with resin, so that the impregnated resin is mixed with the curing accelerator. The method is characterized in that the multi-wound coil is taken out from the resin bath at the point when it has reacted and turned into a gel, and the impregnated resin is heated and cured. In other words, when impregnating a multi-wound coil with resin, the curing accelerator is applied only to the insulation coating of the conductor and the heat-resistant board of the end insulation, and the curing accelerator is not applied to the interlayer insulation or the outer insulation. This prevents a part of the curing accelerator from leaching into the impregnating resin and deteriorating the impregnating resin.

[Embodiments of the invention] Embodiments of the present invention illustrated in the drawings will be described below.

1 to 3 show an embodiment of the present invention, and this embodiment shows a case where a multi-wound resin molded coil used as a high voltage coil is manufactured.

FIGS. 1 and 2 are a cross-sectional view and a plan view of a multi-turn coil. A wavy insulator 2 for main insulation is arranged around the entire circumference of an insulating cylinder 1 made of epoxy glass or the like so that the waves are continuous in the circumferential direction. Note that FIG. 1 shows only a part of this wavy insulator 2. As shown in FIG. This wavy insulator 2
The axial length of is almost the same as the axial length of the insulating cylinder 1.

Next, the conductor 4 is wound in a cylindrical shape a predetermined number of times around the outer periphery of the wavy insulator 2, except for both ends in the axial direction, to form a 1WA conductor winding layer. This conductor 4 is coated with an insulating coating 5 made of an insulating material that is easily impregnated with resin, such as aramid nonwoven fabric. Next, end insulators 3 are placed outside the upper and lower ends of the first conductor winding layer. The end insulator 3 is formed of a band-shaped heat-resistant board 3a with good resin impregnation and a band-shaped board 3b with a large resin content. This end insulator 3 is a heat-resistant board 3a with good resin impregnation properties, and a board 3b with a large resin content ω is sandwiched from both the inner and outer periphery sides and fixed with adhesive tape, glass tape, etc. and bonded.

The material forming the end insulator 3 is a rock wool mixed aramid board (manufactured by Nippon Aroma, trade name: RA board) for a heat-resistant board with good resin impregnation, and a rock wool board (for a large board containing Ijj4 fat). (manufactured by Donami Paper Industries, trade name: Allotx) is used. Subsequently, a wavy insulator 6 as an interlayer insulator is wound and fixed around the entire circumference of the layer consisting of the first conductor winding layer and the end insulator 3 in the same manner as the wavy insulator 2. Thereafter, in the same manner, the wavy insulator 6 and the layer consisting of the conductor winding layer and the end insulator 3 are alternately and concentrically combined and formed sequentially up to the eWA. Thereafter, a multi-wound coil 8 is constructed by winding a nonwoven fabric tape or glass tape with good resin impregnation properties as the outer peripheral insulator 7 around the outer periphery of the sixth conductor-wound layer and the end insulator 3. In addition, U is a conductor winding start part, ■ is a conductor winding end part, and T1 to T6 are tap terminals. In this example, the insulating coating 5 of the conductor 4 and the heat-resistant board 3a of the end insulator 3 are coated with, for example, an imidazole-based curing accelerator IB2MZ (curing accelerator manufactured by Shikoku Kasei, trade name CUREZOL) as a curing accelerator. Attach it in advance. The method of applying this curing accelerator is to add 100MZ to ethyl alcohol.
This was done by diluting the solution at a ratio of 0:90, impregnating the insulator in the solution, and then evaporating the solvent. Next, after pre-drying this multi-wound coil 8, it is set in a resin tank 9 as shown in FIG.
Vacuum pressure impregnation. The multi-il one-turn coil 8 is left in this state, and the curing accelerator attached to each insulator and the impregnated resin 11 react and gel, and when the impregnated resin 11 no longer leaks from the multi-il coil 8, The wound coil 8 is taken out from the resin tank 9. Thereafter, the multi-wound coil 8 is heated in a heating furnace or the like to harden the resin 11 impregnated into the multi-wound coil 8. In this example, as the impregnating resin 11, the main ingredient is T.
VB-2703A liquid (manufactured by Toshiba Chemical, trade name) is used as a curing agent, and B-570 (manufactured by Dainippon Ink, trade name) is used, respectively, and impregnated at a resin temperature of 70 to 90°C. It was left for 2 hours. In this way, as the end insulator 3, a combination of a heat-resistant board 3a and a high-resin-containing board 3b made of rock wool is used, and the curing accelerator treatment is performed at least on the heat-resistant board 3a of the upper end insulator 3. Since the board 3b, which absorbs a large amount of curing accelerator, is not treated with curing accelerator, the curing accelerator attached to the material is dissolved in the impregnating resin during the process of impregnating the coil with resin.
This reduces the so-called curing accelerator migration phenomenon. Therefore, since the impregnated resin does not deteriorate, it is easy to maintain a constant viscosity, and the coil can be used repeatedly by replenishing only the amount of resin impregnated and attached to the coil. On the other hand, in order to prevent resin leakage from the end insulator 3, by sandwiching the heat-resistant board 3a from both the inner and outer periphery of the board 3b, the board 3b can be mounted in a compressed state by being pressed from both sides, so that the resin leakage from that part can be prevented. No resin leakage occurs. In addition, regarding the boundary between the heat-resistant board 3a and the board 3b, due to the action of the curing accelerator attached to the heat-resistant board 3a, it reacts with the impregnated resin and quickly gels, resulting in resin leakage and cracks due to poor adhesion. There have been no outbreaks. Furthermore, the coil (before being impregnated with resin)
Even when transporting a bare coil state), the heat-resistant board 3 a 1. Since the mechanical strength is high, the end insulator 3 will not be displaced, buckled, deformed, or other damage will occur. Therefore, resin molded coils of high quality can be obtained without resin leakage due to damage. In addition, the board 3b, which is not treated with a hardening accelerator, has sufficient resistance to the tension generated when installing the board 3b as the end insulator 3 during coil winding, so it is very easy to work with. It has the advantage of being easier to carry out.

Regarding the structure of the end insulator 3 in the above embodiment, the heat-resistant board 3a at both the upper end and the lower end was explained using a hardening accelerator attached, but the upper end It is not necessarily necessary to attach a curing accelerator to a heat-resistant board made of an insulating material.

[Effects of the Invention] As described above, according to the method of manufacturing a resin molded coil according to the present invention, a heat-resistant board with good resin impregnation properties and a hardening accelerator attached as an end insulator and a hardening accelerator treatment are used. By using a large board with a high resin content in combination, it is possible to prevent deterioration of the impregnated resin due to migration of the curing accelerator during the resin impregnation process, and to prevent the end insulator from being damaged during the resin impregnation process. A resin molded coil that does not cause resin leakage due to deformation, damage, etc. can be obtained.

[Brief explanation of drawings]

1 to 3 each show an embodiment of the manufacturing method of the present invention, and FIG. 1 shows the i-I of the resin molded coil in FIG. 2.
FIG. 2 is a plan view showing a resin-molded coil, and FIG. 3 is an explanatory view showing a step of impregnating the coil with resin. DESCRIPTION OF SYMBOLS 1... Insulating tube, 3... End insulator, 3a... Heat resistant board, 3b... Board with high resin content, 4... Conductor, 5... Insulating coating, 6. ...Wavy insulator, 7...Peripheral insulator. Agent Patent Attorney Noriyuki Chika Yudo Hiroshi Mimata Collection of works 1, 2, 3

Claims (1)

[Claims] A plurality of conductor winding layers each having a conductor having a resin-impregnable insulation coating wound into a cylindrical shape are provided concentrically with interlayer insulators in between, and edge insulators are provided on the outside of the upper and lower ends of each conductor winding layer. When forming a multi-wound coil by attaching a curing accelerator to the insulating coating of the conductor and at least one end of the insulator, the multi-wound coil is impregnated with resin in a fat bath, and the impregnated resin is In the method for producing a resin molded coil, the multi-wound coil is taken out from the resin tank at the point when it reacts with the curing accelerator and becomes gelled, and the impregnated resin is cured. Using a combination of heat-resistant board and board with high resin content,
A method for producing a resin molded coil, characterized in that a curing accelerator is attached only to heat-resistant boards with good resin impregnation properties.