JPS605206B2 - Electrical equipment coil and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrical equipment coil and a method of manufacturing the same.

Conventional methods for manufacturing resin molded coils for transformers, etc.
A method in which the coil body is housed in a mold and a mold resin mixed with filler such as silica powder is vacuum cast inside the mold, and a state in which a fibrous insulating material is wound around the coil body. There is a method in which the fibrous insulating material is vacuum impregnated with mold resin without using a mold.

FIG. 1 is a partially cross-sectional view of a resin molded coil manufactured by the former method, in which 10 is a molded resin layer "21,
22, 23, 24 are coil bodies, 31, 32 are terminals, 4
0' is an interlayer insulator.

Each of the coil bodies 21 to 24 includes an insulated wire 50 wound in several layers with an interlayer insulator 40 interposed therebetween. Each coil millet 2
1 to 24 are arranged one above the other at a predetermined interval, and each of the coil bodies 21 to 24 is connected in series, and a terminal 3 is connected at the end of winding 24 of the upper and lower coil bodies 21 and at the beginning of winding.
1 and 32 are connected, and the coil body 21 in this state
24 are housed in a mold (not shown). Then, mold resin containing filler such as silica is vacuum molded into the mold.
A mold resin layer 10 is formed around the outer periphery of the coil bodies 21 to 24 by curing the mold resin. In this case, the mold resin contains filler, so the viscosity at the time of casting is approximately 1.
It is as high as 0,000 centipoise, and the impregnating property of the mold resin becomes poor. For this reason, it has conventionally been necessary to limit the winding width h of each coil body 21 to 24 to about 10 mm in order to improve the impregnability of the molding resin. Also, the coil body 21~
Conventionally, it has been necessary to limit the winding length of the coil bodies 21 to 24 in order to reduce the thermal stress generated in the molded resin layer at the corners of the coil body 24. In order to satisfy both of these conditions, the coil mill body was divided into a plurality of pieces 21 to 24 as shown in the figure. Therefore, the time for winding the coil bodies 21 to 24, the time for connecting the coil bodies 21 to 24,
This had the disadvantage that it took a lot of time to store it in the mold. In addition, in the former method described above, it is difficult to provide a cooling duct for cooling the coil body within the coil because the coil bodies 21 to 24 are separated, and it is difficult to provide a cooling duct for cooling the coil body within the coil. It is necessary to reduce the current density of the insulated wires 50 constituting the elements 21 to 24, which is not economically preferable. FIG. 2 is a partially cross-sectional view of a resin molded coil manufactured by the latter method, in which an insulated wire 50 with an insulated outer periphery is wound in several layers with an interlayer insulator 40 in between, as in FIG. 1. Coil bodies 21 to 24 are obtained.

A fibrous insulating material 60 with good impregnability is wound in a toroidal shape around the outer periphery of each of the coil bodies 21 to 24 to a thickness of 1 to 2 ribs, and the coil bodies 21 to 24 are molded with a low viscosity molding resin. The mold resin is stored in a tank and subjected to vacuum co-immersion, and then the mold resin impregnated with the insulating material 60 is cured. The coil element body impregnated and cured with the insulating material 60' mold resin (hereinafter referred to as resin-cured coil element bodies 21A to 24A)
is inserted into the outer periphery of the insulating tube 70, and the resin-cured coil body 21 is
A spacer 80 is interposed between A to 24A. The resin-cured coil bodies 21A to 24A are connected in series, and terminals 31 and 32 are connected to the end of the resin-cured coil body 21A and the beginning of the resin-cured coil body 24A. In order to improve impregnating properties in such a manufacturing method, a molding resin with low viscosity is used.

For this reason, while the coil bodies 21 to 24 are pulled up from the mold resin bath and heated to harden, a sealing resin is applied to prevent the mold resin from dripping and creating voids inside the coil bodies 21 to 24. It is necessary to pull up and harden the bodies 21 to 24 while rotating them. Further, as in the former manufacturing method, since the coil bodies 21 to 24 are divided into a plurality of pieces in order to easily manufacture them, it is difficult to provide the cooling duct. This invention was made in view of the above circumstances, and it is economically advantageous because it allows cooling ducts to be easily installed without the need for molds or applying sealing resin, and can also be easily manufactured even with complex coil shapes. The purpose of the present invention is to provide a coil for electrical equipment and a method for manufacturing the same.

The present invention will be described below with reference to the drawings, but first the structure of the electrical equipment coil will be described.

As shown in Fig. 3a and b, the coil bodies 21 and 22 are the same.
A plurality of duct pieces 90 (eight in the figure) are arranged between the coil bodies 21 and 22 at equal intervals in all directions of the axis, thereby providing necessary insulation and cooling. A space 95 is formed. Since the coil bodies 21 and 22 have the same structure except for the difference in size, only the coil body 22 will be explained here. That is, as shown in FIG. 4, a rigid cylindrical insulator 1 having a large number of holes 100a.
00 is disposed, and one layer of insulating wire 60 is wound around the outer periphery of this cylindrical insulator 100 with a porous insulator 111 in between. An interlayer insulator 110 is disposed around the outer periphery of this insulating wire 50, in which the inner and outer peripheries of a film-like insulator 112 are sandwiched between porous insulators lil. One layer of insulated wire 50 connected in series with the insulated wire 50 disposed on the inner circumferential side is wound around the outer periphery of this interlayer insulator 110. An insulator 111 is provided.
Further, end insulators 113 made of porous insulators are provided between the ends of the insulating wires 50 and the ends of the porous insulators 111 in each layer. The width of the Oribe insulator 113 is approximately equal to the thickness of the insulating wire 50, for example, two ribs. The porous insulator 1 1 1 and the end insulator 1
13 is cured by being impregnated with mold resin or vacuum.
It is needless to say that the coil bodies 21 and 22 are connected in series, for example, and terminals are provided in the weave as in the past. A coil having such a configuration is manufactured as follows.

For example, as shown in FIG. 4, a cylindrical insulator 100a is obtained by forming a rigid insulator into a cylindrical shape, in which holes 100a having a diameter of 5 ribs are bored at equal intervals and having a thickness of, for example, 0.25 ribs. A porous insulator 111 with good impregnability is wound around the outer periphery of this cylindrical insulator, for example, to a thickness of 0.5, and one layer of insulating wire 50 is wound around the outer periphery of this porous insulator 111. A porous insulator 1 1 1 is wound around the outer periphery of the insulating wire 50 to a thickness of, for example, 0.5 mm, and a film-like insulator 112 having a high dielectric strength, for example, a length of 0.25 mm is wound on top of this. A porous insulator 111 is further wound thereon to a thickness of, for example, 0.5 ribs, and one layer of insulating wire 50 is wound around the outer periphery of the porous insulator 111. In this way, a coil body 22 is obtained, a coil body 21 is obtained in the same manner, and the coil bodies 21 and 22 are arranged concentrically as shown in FIG. A plurality of pieces 90 are inserted at equal intervals. When winding the insulated wire 50, end insulators 1 to 13 made of a porous insulator are placed on both ends of the coil bodies 21 and 22 so that the thickness is approximately equal to that of the insulated wire 50.
For example, wrap it around 2 inches wide. The entire coil thus formed is vacuum-dried, and then the porous insulator 111 and the end insulator 113 are impregnated with a molding resin, which is heated and cured to complete a molded coil. When impregnated with mold resin, the mold resin may drip from the coil and create voids inside the coil bodies 21 and 22. To prevent this, the viscosity of the mold resin at the time of impregnation must be 500.
It is clear from experimental results that a range of 0 to 20,000 centipoise is optimal. In order to obtain a high viscosity mold resin, a high viscosity mold resin may be used, or a low viscosity mold resin may be adjusted to have a high viscosity by adding a filler.
FIG. 5 shows that the above-mentioned mold resin is used for coil bodies 21 and 22.
This is a diagram showing how the water is immersed in water, and the arrows indicate the route.

Porous insulator 1 from the outer periphery of coil bodies 21 and 22
The impregnating path through 1 to the film-like insulator 112 is about 10 willows at most, and the cylindrical insulator 112 is impregnated from the inside.
The path of impregnation through the 0 holes 100a to the film-like insulator 112 depends on the pitch of the holes 100a, but for example, if the pitch of the holes 100a is set to 20 holes, the impregnation path will be roughly equivalent to 10 scales. The similar clam immersion route is short, so 20
It has been confirmed through experiments that the mold resin can be impregnated to a viscosity of 0.000 centipoise.

When a coil coated with high-viscosity molding resin is taken out from the molding resin tank, there will be excess molding resin attached to the surface, so before entering the curing process, the coil must be heated to a temperature higher than the curing temperature, such as the viscosity of the molding resin - temperature. Characteristics Although it varies depending on the curing temperature, for example, hot air at 130°C is blown onto the surface of the coil to drip excess mold resin.
Cure at a temperature of Porous insulator 111 and end insulator 113 of the resin molded coil thus made
It has excellent crack resistance because it is impregnated with molding resin.

Furthermore, since the resin molded coil made by the above-mentioned method has a thin insulating layer, there is almost no temperature difference between the inside and the surface of the molded coil, so the stress generated by heat is also reduced. In addition, crack resistance is poor in areas with large lumps of molded resin, so
To prevent this, a filler such as silica powder may be added to the mold resin. Since the above-mentioned method of the present invention is an impregnation casting method, a mold is not required, and there is no need to apply sealing resin to prevent mold resin from leaking, so it is possible to provide a cooling duct inside the coil, for example. Can be cast into complex shapes. Furthermore, coil bodies 21 and 22
Since the porous insulating material 111 impregnated with the molding resin is disposed on both sides of the interlayer insulating material 11 and the film-like insulating material 112 having high dielectric strength, the thickness of the interlayer insulating material 11 can be reduced. Insulation between the coil bodies 21 and 22 is achieved by a porous insulator 111 impregnated with mold resin on the outer periphery of the coil mill 22 and a space 95 and a cylindrical insulator 100 on the inner periphery of the coil body 21. -Since it is composed of a porous insulator 111 impregnated with a resin, the voltage is mostly applied to the space 95.
However, since the porous insulator 111 is between the two electrodes (the insulated wire 50), the partial discharge voltage is high and the impulse withstand voltage is also high. The present invention is not limited to the embodiments described above, but can be modified as follows.

In other words, depending on the rating of the electrical equipment, the film-like insulator 11
2 can be omitted. In this case, the cylindrical insulator 10
Even if the zero hole 100a is not formed, the mold resin can be completely impregnated through the outermost porous insulator 111 and the porous insulator 111 interposed between the layers. Furthermore, depending on the rating of the electrical equipment, it may be more economical to design the number of layers to be an odd number.

In that case, the coil body may be arranged as shown in FIG. That is, when the number of layers of the coil body 22 is reduced to one, the molding resin can be impregnated from the outer periphery, so that the hole 100a of the cylindrical insulator 100 can be eliminated. Furthermore, since the mold coil described above uses a porous insulator 111 and a thin, rigid cylindrical insulator 100, its mechanical strength is weak until it is impregnated with the mold resin and hardened, so it has the disadvantage of requiring disposable tools for transportation. There is.

To solve this problem, as shown in FIG. 7, a plurality of duct pieces 115 are arranged at equal intervals above the secondary coil 114, which has thick insulated wires and strong mechanical strength, to create a space 116 necessary for cooling and insulation. If the coil elements 21 and 22 are directly wound by providing a holder, transportation is possible without a special jig. Also, the secondary coil 114
The molded coil 117 (primary coil) and the secondary coil 1 described above are formed by impregnating and casting a molding resin together with the molded coil 117 (primary coil) and the secondary coil 1.
14 can be firmly bonded together via the duct piece 90, for example, the axial mechanical force generated by a secondary short circuit of a transformer can be applied to the coil holder and wall lamp (both shown in the figure) that attach the primary coil and secondary coil. This has the advantage of simplifying the coil holder and wall lamp. In addition, the coil body 2 is directly placed on the secondary coil 114.
2, the molded coil can be made into a rectangular tube shape other than a cylinder, as shown in FIG. In the case of a conventional rectangular cylindrical molded coil, the core inserted inside the coil has a rectangular cross section, so it is lighter in weight than a stepped core.
Although it has advantages such as low processing costs, it can only be applied to small capacity transformers, for example, because the mechanical force in the radial direction is weak. However, in this invention, since both the primary coil and the secondary coil, which are arranged concentrically, can be impregnated with mold resin, the mechanical force in the radial direction is improved.
It is possible to manufacture transformers of approximately 00KVA. According to the invention described above, a cooling duct (referred to as a space in the embodiment) can be easily provided without the need for a mold or the application of sealing resin, and even if it has a complicated shape, it can be manufactured easily. It is possible to provide an electrical equipment coil and a method for manufacturing the same which are both economically advantageous.

[Brief explanation of the drawing]

1 and 2 are partially sectional front views of different conventional molded coils, and FIGS. 3 a and 3 b are partially sectional front views and plan views of an embodiment of the electrical equipment coil according to the present invention. Figure 4 is a front view of the rigid insulator used in the same example, Figure 5 is a diagram for explaining the state in which the mold resin is impregnated in the same example, Figures 6, 7, and 8. The figures are a partially sectional front view, a top view, and a plan view of different modifications of the invention. 21-24... Coil body, IQ0...
・Cylindrical insulator, 100a...hole, 110...
...Interlayer insulator, 111... Porous insulator, 1
12...Film-like insulator, 113...
・End insulator, 114...Secondary coil, 115
...Duct piece, 116...Space,
117...Primary coil. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Scope of Claims] 1. A plurality of cylindrical coil bodies are arranged concentrically, and a space is formed between the coil bodies by a plurality of duct pieces, and the inner and outer peripheries of each of the coil bodies are and an electrical equipment coil having at least a porous insulator between layers, the porous insulator being impregnated and cured with a molding resin. 2. At least a porous insulator is provided between the inner periphery, outer periphery, and layers of a plurality of cylindrical coil bodies, and the porous insulator is disposed concentrically with a space between the coil bodies. A method for manufacturing an electrical equipment coil, comprising impregnating and casting a mold resin having a viscosity of 5000 centipoise or more or a mold resin containing a filler through the space, and curing the product.