JPH01238004A - Resin-molded coil and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve electrical insulation characteristics and cooling characteristics and miniaturize a unit by fixedly mounting an inner coil and an outer coil through a connecting member for connecting first and second resin layers. CONSTITUTION:A resin-molded coil includes an outer coil 10 and an inner coil 20 both disposed coaxially. A first resin layer 20a is formed on one end surface of the inner coil 20 while a first resin layer 20b on the otherend surface. A second resinlayer 10a is formed on one end surface of the outer coil 10, oppositely to the first resin layer 20a. Further, a second resin layer 10b is formed on the other end surface, oppositely to the first resin layer 20b. The first and second resin layers 20, 10 extend coaxially in an axial direction of the coil. A resin duct 3, a connecting member, is formed between the first and second resin layers 20a and 10a, and between 20b and 10b as one body for fixing the inner and outer coils 10 and 20. Therefore, any electric field is prevented from concentrating to improve an air flow between the coils.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to stationary induction equipment such as molded transformers, and particularly to a high and low voltage integrated resin molded coil suitable for electrical characteristics and cooling characteristics.

[Conventional technology]

Conventionally, air ducts for molded coils have had a structure in which a wave-shaped spacer is disposed at the height of the coil in the axial direction between the inner and outer coils to form an air duct, as described in Japanese Patent Publication No. 60-5213.

[Problem to be solved by the invention]

Conventional inner and outer coil integrated technology places an insulator shaped into a corrugated or circular shape between the inner and outer coils to reduce the degree of concentration of electric field between the two coils. Cooling characteristics were sacrificed because it was necessary to increase the distance between the coils and to strengthen the insulation of each opposing coil.

Insulators are also wound between the inner and outer coils.

Resin-molded coils injected with casting resin have the risk of significantly reducing the corona characteristics due to peeling of the insulating layer between both coils and the windings, and also significantly sacrifice cooling characteristics in terms of heat dissipation of the coil. Ta.

An object of the present invention is to provide a resin molded coil that can be made smaller by improving the electrical insulation properties and cooling properties between the inner coil and the outer coil, and a method for manufacturing the same.

[Means to solve the problem]

The objects are arranged concentrically and spaced apart from each other.

and a resin molded coil comprising an inner coil and an outer coil, each of which is molded with resin, a first resin layer formed on one end surface of the inner coil so as to extend in the axial direction of the inner coil, and the outer coil. a second resin layer formed on one end surface of the outer coil to extend in the axial direction of the outer coil and facing the first resin layer;
This is achieved by providing a connecting member that connects the resin layer and the second resin layer, and fixing the inner coil and the outer coil by the connecting member.

[Effect]

Since the connecting member that fixes the inner coil and the outer coil together is provided between the insulating layers formed on the end face of the coil,
Since only an air layer exists between at least the opposing windings between the inner and outer coils, it is as if the inner and outer coils have been disassembled and the distance between the two coils is maintained appropriately. Therefore, since there is no substance with a higher dielectric constant than air between the inner and outer coil windings, it is possible to prevent the concentration of electric fields, prevent deterioration of corona characteristics between the inner and outer coils, and reduce AC withstand voltage and impulse voltage. It is possible to prevent the electrical strength from decreasing. Furthermore, since the connecting member is present only at the ends of the coils, the air flow between both coils becomes smoother, further improving the cooling characteristics.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to Figs. 1 to 16.6 A first embodiment of the present invention will be explained with reference to Figs. The manufacturing method of this embodiment will be described below. First, wire is wound around a winding form through an interlayer insulator to form a winding wire.
The inner winding 2 and the outer winding 1 are respectively prepared as primary windings, and the inner winding 2 and the outer winding 1 are concentrically combined and arranged in a casting mold 8, as shown in FIG. After casting the injection resin 6, a resin block 7, which is made of the same material as the injection resin 6 and whose surface has been roughened to improve adhesion, is placed on the bottom and inner periphery of each winding 1 and 2, or on the outer periphery. Insert it on the side.

Furthermore, in order to integrate both windings between the two windings, space molds 4 and 5 as shown in FIG. 5 are used to form resin ducts 3 as connecting members provided at the upper and lower ends of the coil.
Insert and place. Thereafter, the casting resin 6 is injected from the upper part of the injection mold 8 and cured in a curing furnace to form the winding wire 1.
An insulating layer is formed on the outer periphery and both end surfaces of 2, and a resin duct 3 is formed.

After curing, the space molds 4 and 5 are removed as shown in FIG. 6, and the casting mold 8 is also removed to form a resin molded coil with integrated inner and outer windings as shown in FIGS. 1 to 3.

The space mold in this example has an inner coil obtained by forming insulating layers on the inner and outer peripheries and both end surfaces of the inner winding 2, and an inner coil obtained by forming insulating layers on the inner and outer peripheries and both end surfaces of the outer winding 1. It is interposed over the entire circumference between the outer coil and the outer coil, and is divided into predetermined lengths in the circumferential direction so that it can be easily removed after hardening. A mold 4 shown in FIG. 5(a) is an example of a mold, and a groove 4a for forming a resin duct 3 is provided on one side in the axial direction of the mold. . The mold 4 is divided into predetermined lengths in the circumferential direction, and the grooves 4a are arranged at different positions vertically for each adjacent mold. In order to provide the resin duct 3, which is a connecting member, with a good balance between the upper end flange and the lower end of the resin molded coil, it is desirable to have an even number of molds 4. , ), the coil is pulled out in the direction opposite to the opening of the groove 4a, thereby forming a resin duct 3 between the resin layers on the end face of the coil.

The structure of the mold is not limited to this, and the mold 5 may have the structure shown in FIG. 5(b). A notch 5a is formed for forming the number 3. After the resin has hardened, the mold 5 is pulled out in the direction opposite to the axial opening of the notch 5a, as shown in FIG. can be formed. The resin molded coil manufactured in this way includes a first resin layer 20a formed on one end surface of the inner coil 20 so as to extend in the axial direction of the inner coil 20;
A first resin formed on the other end surface of the inner coil 2o so as to extend in the axial direction of the inner coil 20! 20b, and a second resin M20b formed on one end surface of the outer coil 1o to extend in the axial direction of the outer coil 10 and facing the first resin M20a.
a resin layer 10a, and a first resin M formed on the other end surface of the outer coil 10 so as to extend in the axial direction of the outer coil 10.
20b and a second resin layer 10b facing the resin layer 10b.

The first resin layer 20a, the second resin layer 10a, and the first
A resin duct 3 as a connecting member is integrally formed between the resin layer 20b and the second resin layer 10b, and fixes the inner coil 20 and the outer coil 1o.

Next, a second embodiment of the present invention will be described with reference to FIGS. 8 to 13.

In this embodiment, the present invention is applied to an FRP mold type.The manufacturing method of this embodiment will be explained below. 1st
As shown in FIG. 2, first, a prepreg insulating layer 9 is formed by winding a prepreg chive or a prepreg sheet around a winding form 12. An inner winding 2 is made by alternately winding wires and glabellar insulators. Then, a prepreg insulating layer 9 is formed on this outer periphery in the same manner as on the inner periphery. At this time, the prepreg insulating layer 9 at the end of the winding is bent inward, so the insulating material 11. For example, wrap and insert thick Nomex, fully cured prepreg sheet material, or tape material.
After winding the inner winding, insert resin duct 3 on the outside of the inner winding.
A space mold 4 for forming a space is placed around the entire circumference between the inner coil and the outer coil. Next, the outer winding 1 is wound in the same manner as the inner winding 2. Thereafter, as shown in FIG. 3, both ends of both windings are filled with Patelesine 1O and hardened to form an insulating layer. To form an insulating layer, one side of the winding wire may be filled with Patele resin 1o, and the casting resin 6 may be injected from the other. The resin duct 3 is manufactured by filling or injecting the putty resin 10 or the casting resin 6. After the resin and prepreg insulating layers have hardened, the space mold 4 is removed, and an FRP mold type resin molded coil shown in FIGS. 8 to 10 is completed.

Note that the mold 5 shown in FIG. 5(b) may be used as the space mold.

The resin molded coil manufactured in this way has a first resin layer 40a formed on one end surface of the inner coil 40 so as to extend in the axial direction of the inner coil 40, and an inner coil formed on the other end surface of the inner coil 4o. A first resin layer 40b formed to extend in the axial direction of the outer coil 30, and a second resin layer formed on one end surface of the outer coil 3o to extend in the axial direction of the outer coil 30 and facing the first resin layer 40a. layer 30a
and a second resin layer 30b formed on the other end surface of the outer coil 30 to extend in the axial direction of the outer coil 30 and facing the first resin layer 40b; The resin layer 30a and the first resin layer 40b and the second
A resin duct 3 as a connecting member is integrally formed between the resin layer 30b and the inner coil 40 and the outer coil 3.
Fix o.

According to the above embodiment, both the inner and outer windings can be molded with resin and can be integrated without sacrificing insulation, so when assembled with the iron core as one device, it is not only easy to work, but also easy to support the coil. becomes.

In the above embodiment, as shown in FIGS. 4 and 11, the resin ducts 3 formed between both windings are arranged alternately at the upper and lower parts of the coil. May be co-located.

An example of such a configuration will be described as a third embodiment of the present invention with reference to FIGS. 14 and 15.

In this embodiment, a ring-shaped resin block 13 is inserted between the end face of the inner coil 20 and the end face of the outer coil 10, and this resin block 13 is hardened together with the insulating layer on the end face to form the inner coil 20. outer coil 1
0 is fixed. The resin block 13 consists of an inner ring part 13c, an outer ring part 13b, and a connecting part 13a as a connecting member, and is made of the same material as the resin 6 to be filled. Ring part 1
The inner circumferential surface of the ring portion 3c and the outer circumferential surface of the ring portion 13b are roughened to improve compatibility with the resin to be cast.

In this embodiment, the space mold is divided into a mold 15 inserted below the joint 13a of the resin block 13 and a mold 16 inserted into other parts, as shown in FIG. . The space mold 15 is the space mold 5
It is formed by removing the notch 5a, and the width is approximately equal to the width obtained by subtracting the width in the circumferential direction. Space mold 1
6 has the same shape as the space mold 15, but differs from the mold 15 in width in the circumferential direction and length in the axial direction. That is, the mold 16 has a circumferential width that is equal to or slightly larger than the circumferential width of the connecting portion 13a of the resin block 13, and an axial length that is equal to or slightly larger than the circumferential width of the connecting portion 13a of the resin block 13. The length is approximately equal to the length. The molds 15 and 16 are inserted between the inner coil 20 and the outer coil 10 during filling with casting resin. The molds 15 and 16 are arranged adjacent to each other in the space between the inner coil 20 and the outer coil 10 over the entire circumference. Mold 15 and Mold 1
The joint portion 13a of the resin block 13 engages with the groove-shaped portion formed by the difference in length in the axial direction of the resin block 131, resulting in 131 turns of the resin block! 1.2. Positioning between the molds 15 and 16 can be facilitated. In addition, as shown in FIG. 16, the inner peripheral surface 13c and the outer peripheral surface 1 of the resin block 13
3b may be formed with a protrusion 13d to position the resin block 13 in the axial direction. According to this, the connecting portion 13a can be provided reliably separated from the opposing portion of the roll $1.2. .

To remove the gold piece after the resin has hardened by heating, first, the mold 15 is pulled out in the axial direction, and then the mold 16 is moved in the circumferential direction to be shifted from the position below the connection part 13a, and then moved in the axial direction. In this embodiment, the resin block 13 is formed into a ring shape in advance, but it may be divided into a plurality of pieces in the circumferential direction and combined into a ring shape.

〔Effect of the invention〕

According to the present invention, since the connecting member that integrates the inner and outer coils is provided on the resin layer at the end of the coil, it is possible to prevent concentration of the electric field between the two coils at opposing portions of the inner and outer windings. The electrical insulation properties between both coils can be improved or the interval between both coils can be narrowed, making it possible to reduce the size of the coil.

Also, since the coil cooling air flows smoothly between both coils, the cooling characteristics of the coil are further improved. Furthermore, since the coil can be integrated, the mechanical strength against electromagnetic mechanical force in the event of a short circuit is improved.

This has the advantage that the equipment can be easily assembled.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional perspective view showing the structure of a resin molded coil in a first embodiment of the present invention. FIG. 2 is a partially sectional plan view of the resin molded coil in this embodiment, FIG. 3 is a side view of the resin molded coil in this embodiment, and FIG. 4(a). (b) and (C) are the AA' cross sections in FIG. 2, respectively. Cross-sectional view showing the BB' cross section and the c-c' cross section, Fig. 5 (a
) and (b) are space type 4 and space type 5, respectively.
A perspective view showing a state in which the two are combined, FIGS. 6(a) and (b)
7(a), (b), and (c) are plan views showing the extraction directions of the space mold 4 and the space mold 5, respectively.
are AA' section 1, BB' section, and c in Fig. 2, respectively.
A sectional view showing the state of the -c' cross section during resin casting,
FIG. 8 is a partially cross-sectional perspective view showing the structure of a resin molded coil according to a second embodiment of the present invention, FIG. 9 is a partially cross-sectional plan view of the resin molded coil according to the present embodiment, and FIG. FIG. 10 is a side view of the resin molded coil in this example, and FIG. 11(a). (b) and (C) are the EE' cross section and F-
FIG. 12 is a cross-sectional view showing the state of this embodiment when winding; FIG. 13 is a cross-sectional view showing the state of this embodiment when filled with resin. FIG. 14 is a partially sectional perspective view showing the structure of a resin molded coil in a third embodiment of the present invention, FIG. 15 is a perspective view showing a state in which space molds 15 and 16 are combined,
FIG. 16 is a sectional view showing the main parts of this example during casting. 3.13a: Connection member, 10-30: Outer coil, 10
a, 30a: second resin layer, 10b, 30b: second resin layer, 20.40: inner coil. 20a', '40a: first resin layer, 20b, 40b:
First resin layer No. (Fig. 1ab: $2 Meki J!jJ Fig. 3 t)ノ＄ 7 Zutei 8 Figure 30 Hisashi: Size 42, U-shaped eyebrows 4
ob: Prisoner hr # Tsukisho Ashi3 ob: Humiliation 2. -#Sugesho Formation Figure 9 $72 Figure 3 Figure 271

Claims (2)

[Claims] 1. In a resin molded coil consisting of an inner coil and an outer coil that are arranged concentrically apart from each other and are each molded with resin, a resin molded coil is formed on one end surface of the inner coil so as to extend in the axial direction of the inner coil. a first resin layer, a second resin layer formed on one end surface of the outer coil to extend in the axial direction of the outer end coil and facing the first resin layer; 2
A resin molded coil comprising: a connecting member for connecting resin layers, and the inner coil and the outer coil are fixed to each other by the connecting member. 2. The first coil winds the inner coil and the outer coil, respectively.
a second step of concentrically combining the inner coil and the outer coil; a third step of inserting a mold forming a connecting member between the inner coil and the outer coil; A fourth step of filling each end face of the inner coil and the outer coil with resin to form a resin layer and a connecting member, and a fifth step of removing a mold forming the connecting member. A method of manufacturing a resin molded coil.