JPS6286810A - Manufacture of resin mold coil - Google Patents

Abstract

PURPOSE:To improve insulating and working performances, by putting thin insulating films on conductors and forming insulation coating composed of highly-enforced fibrous material around them with hardening accelerator attached and then hardening them. CONSTITUTION:Enamel films are formed by baking resin such as polyester on aluminum or copper conductors 1, and insulation coating 3 is formed on them by winding insulating materials, e.g., aramid non-fabrics, which are superior in resinous impregnation and beforehand attaching hardening accelerator reacting to the impregnation resin, so as to compose insulating conductors 4. These conductors 4 are wound on an insulating bobbin 6 through insulating materials 7 and 8. After the hardening accelerator is attached to the lower end part of this coil element, the coil element is put into a resin jar to perform resinous impregnation. At the time when the resin impregnating the insulating material becomes gelatinized with the impregnation resin reacting to the hardening accelerator attached in advance, the coil is drawn out from the resin jar and then the impregnation resin is hardened by heating to obtain a united resin mold coil.

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 resin molded coils: 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 of its economical advantages.

One method that does not use this mold is to attach a curing accelerator that reacts with the impregnated resin to the insulator in advance, and form an insulating layer by reacting with the impregnated resin. This method simplifies the resin processing process. There is an advantage that

The inventor filed a patent application in 1986-6375 for such a manufacturing method.
In No. 4, the following method is proposed. First, in order to secure a cooling airway and an insulation distance, a wavy insulator is placed on top of the insulating tube, and an insulated conductor coated with a heat-resistant nonwoven fabric impregnated with resin is wound on top of the wavy insulator. This insulated conductor is made by adhering in advance a curing accelerator that reacts with the impregnated resin to an insulating tape forming an insulating coating. Thereafter, each layer is sequentially wound while arranging the wavy insulator in the same manner, and end fillers are inserted outside the upper and lower ends of each layer to form a multi-wound coil. Thereafter, an outermost insulating layer is formed on the outermost periphery of the coil using an insulating material to which a curing accelerator has been previously attached, thereby forming a coil body. A curing accelerator is attached to the lower end of the coil element, and then the element is placed in a resin bath and impregnated with resin. Once it has reacted and turned into a gel, take it out of the resin tank,
Heat and harden in a drying oven or the like to obtain an integrated resin molded coil.

In this method of manufacturing resin molded coils, an insulating tape coated with a curing accelerator is directly wound onto the conductor to form an insulating coating. If a hardening agent is used and left standing for a long time before resin impregnation treatment, the curing accelerator and copper will react and green rust will occur. In addition, a resin layer is formed on the conductor, but the boundary between the resin and the conductor is prone to microcracks due to the difference in linear expansion coefficient between the two, so the temperature rise cannot be increased. In addition, it is necessary to make the insulating layer thick to prevent dielectric breakdown even if minute cracks occur. For this reason, it varies depending on the voltage, but 2 OK
In V class resin molded coils, it is necessary to cover the conductor with an insulation coating of about 1#, which results in a relatively large coil with a poor space factor of the conductor. In particular, in large-capacity coils, an insulated conductor in which a plurality of conductors are arranged in parallel is used, and in this case, the space factor of the conductor is extremely poor.

[Object of the Invention] The present invention has been made to address these problems, and provides a method for manufacturing a resin molded coil that has good insulation properties, is compact, and improves workability by improving the insulated conductor. This is what we provide.

[Summary of the Invention] The resin molded coil according to the present invention has a thin insulating coating applied to a conductor, and an insulating material with good resin impregnation property, to which a curing accelerator that reacts with the impregnating resin has been attached in advance, is wrapped around the outer periphery of the conductor. After winding this insulated conductor to form a coil element, it is stored in a resin bath and impregnated with resin, and the impregnated resin reacts with the hardening accelerator applied in advance. When the resin gelled, the coil conductor was removed from the resin bath and heated to harden. In other words, the conductor is insulated by a thin insulating coating formed on it, and the insulating coating around the outer periphery of the conductor allows other constituent materials and insulated conductors to be bonded together, resulting in improved moisture resistance and mechanical strength. Not only is it easy to measure, but copper conductors can now be used, allowing for miniaturization.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to drawings. FIG. 3 shows an example of an insulated conductor used in the method of manufacturing a resin molded coil of the present invention. Aluminum is an insulating material with good resin impregnation properties, such as aramid, which is made by baking a resin such as polyester or amide-imide ester imide onto a copper conductor 1 to form an enamel film, and then adhering a curing accelerator that reacts with the impregnating resin in advance. An insulated conductor 4 is formed by winding a nonwoven fabric, a high-strength fiber material, or the like to form an insulating coating 3. As shown in FIGS. 1 and 2, this insulated conductor 4 is wound onto an insulating tube 6 made of FRP or the like through a main insulating corrugated insulator 7 for keeping the cooling airway and insulation interval constant. Form the first layer. Subsequently, while arranging the wavy insulator 8 in the living room, a plurality of layers are wound concentrically with the required number of turns to form a multilayer coil body. Incidentally, end fillers 10 are also provided at the upper and lower ends of each wound layer in the same manner as in the prior art. Thereafter, the outermost layer 9 of the coil body is formed by winding a high-strength m-thread material, for example, a glass tape, to which a hardening accelerator that reacts with the impregnated resin has been applied. Note that (1) to (T6) are tap terminals. After a curing accelerator was attached to the lower end of the coil body formed in this way, it was placed in a resin bath and impregnated with resin, and the impregnated resin reacted with the curing accelerator attached in advance to impregnate it into the insulator. When the resin has gelled, the coil is taken out from the resin bath, and the impregnated resin is cured by heating in a heating furnace or the like to obtain an integral resin molded coil. In this example, the imidazole curing agent IB2MZ was used as the curing accelerator to be applied in advance.
(Shikoku Ishisei product name), dilute this 182MZ with ethyl alcohol in a range of 1 to 10%, and use the liquid to attach a curing accelerator to insulating materials and high strength ￥＠Ifi
It was used by impregnating the material and evaporating the solvent. As the impregnating resin, TVB-2703A liquid (manufactured by Toshiba Chemical, trade name) was used as the main agent, and 8-570 (manufactured by Dainippon Ink, trade name) was used as the curing agent, and the impregnation was carried out at a resin temperature of 70 to 80°C. The resin molded coil was left to stand for 1 to 2 hours to obtain an integral resin molded coil.

Since the molded coil constructed in this manner has the enamel film 2 on the conductor 1, the hardening accelerator previously attached to the insulating material does not come into direct contact with the conductor 1. Therefore, even if copper is used for the conductor 1, green rust will not occur. Therefore, it is possible to use a copper conductor, which has a higher conductivity than an aluminum conductor, so it can be made smaller.

In addition, since the enamel film 2 itself has excellent dielectric strength, the insulating film 3 wound thereon retains the impregnated resin and fixes the insulated conductors together. It is sufficient as long as it has the thickness necessary to fix the Q
, about imm thick, high strength tU with hardening accelerator attached
It is sufficient to simply wind the material. Therefore, the space factor of the conductor can be improved, and a small and lightweight resin molded coil can be obtained. On the other hand, even if the insulation thickness becomes thinner, the wavy insulation provided for cooling acts as a 9V insulation bar, so the insulation properties have almost no effect on the insulation thickness of the insulated conductor, and rather the insulation thickness is thinner. The cooling characteristics improve accordingly. Regarding microcracks, since the enamel film 2 is applied on the conductor 1, even if microcracks occur in the resin layer above it, there is no problem with insulation. We can provide good resin molded coils.

The explanation so far has been about the case where an enamel film is formed as a thin insulating film, but for economic reasons and when it is difficult to form an enamel film, it is possible to use a thin insulating tape such as polyimide coil or aramid vapor on the conductor instead of the enamel film. A similar effect can be obtained by using an insulated conductor having an insulating coating made of a high-strength fiber material on which a thin insulating coating is formed by winding the insulating conductor to form a thin insulating coating, and a hardening accelerator is previously applied thereon. In particular, in this case, the lap part of the insulating tape that forms the insulating film is also impregnated with the impregnated resin, and the outer insulating coating to which the curing accelerator has been applied prevents the impregnated resin from flowing out. There is also the advantage that the weak points of the insulating tape winding can be strengthened since breakage from the lap part can be prevented. Furthermore, a large capacity resin molded coil may use a plurality of insulated conductors wound in parallel. In this case, as shown in Fig. 4, a plurality of conductors each having an enamel film 2 applied on top of the conductor 1 are bundled together, and a high-strength fiber material to which a curing accelerator has been applied in advance is wound over the conductors. After forming the insulating coating 3, one insulated conductor 5 is constructed. A similar effect can be obtained by forming a coil body using this insulated conductor 5, impregnating it with resin, and curing it to manufacture a resin molded coil. Particularly in this case, since the potentials between the parallel conductors are the same, it is only necessary to have an insulating layer between them to reduce eddy current loss, and if this is made of an enamel film, the space factor will be further improved. Furthermore, even if there is a gap between adjacent conductors such as in a round wire, the impregnated resin will enter, and the insulating coating 3 on the outer periphery will act as a seal to prevent the impregnated resin from flowing out, so that no defects will be formed.

On the other hand, in order to reduce eddy current loss, when parallel conductors are used, the conductors are transposed at appropriate parts, but it is sufficient to transpose the plurality of conductors inside the insulation coating 3 as appropriate.

[Effects of the Invention] As explained above, the method for manufacturing a resin molded coil according to the present invention has the advantage of being able to reduce the thickness of the insulation coating, use a copper conductor, and provide a small resin molded coil with a good space factor. Manufacturability is improved because the thickness of the insulating coating can be thin instead of the hook.

[Brief explanation of drawings]

Figures 1 and 2 are longitudinal and cross-sectional views showing a coil body used in the method of manufacturing a resin-molded coil of the present invention, and Figure 3 shows an example of an insulated conductor used in the manufacturing method of the present invention. The sectional view shown in FIG. 4 is a view corresponding to FIG. 3 showing another embodiment. DESCRIPTION OF SYMBOLS 1... Conductor, 2... Enamel coating, 3... Insulating coating, 4.5... Insulated conductor 6... Insulating tube, 7...
- Wavy insulator for main insulation, 8... Wavy insulator for interlayer insulation, 9... Outer insulating layer, 10... End filling. Agent Patent Attorney Noriyuki Chika Yudo Hiroshi Mitsumata Figure 1 Figure 4

Claims (4)

[Claims] (1) Using an insulated conductor with a thin insulating coating on the conductor and an insulating coating made of a high-strength fiber material to which a curing accelerator has been attached in advance to the outer periphery, this insulated conductor is wound into a cylindrical shape to form a coil. After forming the element body, impregnating it with a resin, and when the impregnated resin reacts with the curing accelerator and gelling it, take out the coil element body from the impregnated resin and harden the impregnated resin to produce a resin molded coil. Method. (2) The method for manufacturing a resin molded coil according to claim 1, wherein the thin insulation coating of the insulated conductor is formed of an enamel coating. (3) The method for manufacturing a resin molded coil according to claim 1, wherein the thin insulation coating of the insulated conductor is formed of a thin insulation material. (4) The insulated conductor is formed by providing an insulating coating made of a high-strength fiber material to which a curing accelerator has been applied in advance on the outer periphery of a plurality of conductors each having a thin insulating coating. 2. A method for manufacturing a resin molded coil according to item 1.