JPS6025108A - Method of producing insulated conductor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing an insulated conductor using an impregnation method that leaves no resin-unimpregnated portion in an insulating layer.

[Technical background of the invention and its problems]

Conventionally, an impregnation method has been used to manufacture insulated conductors. However, the impregnation method uses resin to fill the voids in the lining layer, which is made by wrapping multiple layers of insulating tape.
If the resin does not reach these voids, it will become an insulated conductor containing voids, and when the insulated conductor is used to form the windings of electrical equipment and is operated, the voids will cause deterioration due to radiation and moisture absorption. , thermal deterioration, and deterioration due to mechanical stress based on stress concentration. Therefore, in the case of the impregnation method, the resin reaches every void in the insulating layer,
Filling with resin is essential for obtaining high-performance insulated conductors and, ultimately, insulated coils. Especially with high voltage coils,
Since multiple layers of insulating tape, mainly made of mica tape, are wound, in order to avoid leaving any voids in the insulating layer, the vacuum is degassed in a vacuum impregnation tank beforehand, and then a low-viscosity resin is fed into the tank. A vacuum pressure impregnation method is used in which the coil is immersed in the resin, pressure is applied to the resin for a long period of time, the coil is removed from the resin, and the coil is heated to impregnate the insulating layer and harden the resin. It is. However, even with this -VJ method, if the insulating tape is rolled up too tightly, or if the adhesive in the insulating tape is somewhat sticky and the turns of the insulating tape stick together, there may be some unresolved material in the insulating layer. The impregnated portion may remain, resulting in an insulated coil with poor characteristics and a gap.

Insulated conductors (including coils) with such poor characteristics are those in which insulation Jd +21 is provided by wrapping an insulating tape around a conductor (1) with no irregularities on the surface, as shown in Figure 1, or insulated conductors (including coils) with As shown in the figure, there is an insulation breakdown (4) in the core wire (3).
When forming a conductor (1) by bundling a plurality of strands (5) provided with 11. j f6) is buried by the adhesive used to bundle the wires, or whether it is
1) The present inventor discovered that this phenomenon is often seen in cases where the wires are filled with solder fm and solder used to connect the core wires f31 and +31 at the ends.

Generally, the insulating layer (2) of the electrical conductor (1) is impregnated with resin by applying an insulating tape 7 to the insulating layer (2) as shown in FIG.
/Interlayer formed by stacking many layers of double-wound material (
8) and proceed in the direction of arrow A from the insulation surface side. However, if the insulating layer (2) is thick, the distance required for impregnation to reach the conductor (1) is long, and therefore the impregnation may not be completed within an economically reasonable time. At the end of the insulating layer (2), it is also impregnated into the interlayers (8) of the insulating layer (2) as shown by arrow B. However, in this case as well, if the length of the conductor is long, the impregnation cannot be completed within an economically reasonable period of time, as described above.

Generally, the insulation In+23 and the strand (5) shown in FIG.
(5) The gap (6) formed between the mutual corners is formed by the insulating layer (2
) is wider than the gap (8) formed between each layer, so the resin permeates through this gap (6) along the strands (5) as shown by the arrow I:r]C in Figure 3, and the strands The resin is impregnated between the insulation layers (2) from the wire (5) side as well. If this void (6) is filled with adhesive, solder, silver solder, etc., the wire (
The path of arrow C impregnating along 5) is cut off, and the path of arrow A,
Impregnation can only be carried out along the path indicated by arrow B. If a conductor (1) without irregularities shown in FIG. 1 is used, there is no possibility that the path indicated by arrow C will be formed from the beginning. Therefore, 41. of unevenness. An insulated conductor with poor characteristics is likely to be produced when an n-conductor is used or when the gap between the corners of the strands and the insulating layer is filled with adhesive, solder, silver solder, etc. Among insulated conductors, high-voltage coils in particular are generally extremely expensive, and it is necessary to reduce the incidence of such defective insulated conductors to zero.

[Purpose of the invention]

An object of the present invention is to provide a method for producing an insulated conductor that can be economically impregnated with resin.

[Summary of the invention]

In accordance with the present invention, a method for forming an insulated conductor in which a plurality of insulating layers are formed by winding an insulating tape around a gas conductor, and this insulating layer is impregnated with resin and cured, the total insulation 1- Let N be the total 1-edge layer layer, and divide the total 1-edge layer layer into 2N/7 inner insulation edges with a value of 1 or more, - and the remaining number of outer insulation edges, and divide both edge layers m 1ffl is located approximately in the center of the conductor, parallel to the conductor, and in the longitudinal direction, with a spacer interposed between the ends of the resin so that both ends protrude from at least the ends of the outer insulating layer. It has a vj characteristic in impregnating and curing the resin, and by impregnating the resin even from the gaps created by the insulating spacer, it is possible to make a good insulated conductor with no unimpregnated parts in a short time. The reason why the position of the insulating spacer was set at the above-mentioned position was that the inner insulating layer and the outer insulating layer were well impregnated with resin on average according to experimental results.
This is to avoid this because if the insulating spacer is placed directly on the conductor, the insulating layer will easily peel off from the conductor, and if peeling occurs on the conductor 1u where the Zth'4 field is the highest, deterioration will easily occur.

[Implementation sequence of the invention]

Practical Example 1 A first practical example of the present invention will be described below with reference to FIGS. 4 and 5. This S arrangement shows one insulation of the insulated coil connection rH of rotation I 1 number.

A rectangular cross section with no irregularities on the surface (calyx book (1), thickness 0
．． 24 mg, 32 width, 7 to 15 layers of insulating tape made of glass I-A11i sleeve-strength tape with 7 to 15 layers of epoxy resin as adhesive, wound 5 times in 1/2 layer C1, that is, 5 layers of inner insulation layer + 97 form. On the outside of the inner insulating layer (9), the thickness -Δ1 sa
i, a glass woven tape with a width of 4011 is bonded with an adhesive as a spacer 01, and both ends of the spacer OI are made to protrude from the ends of the inner insulating layer (9). Wrap the same insulating tape used for the inner insulating layer (9) around the outer circumference with 1/2 layer for 25 minutes.
By winding, 25 outer insulating layers OD were formed.

Therefore, the total number of insulating layers (2) N is 30 (N=5+25=30). In this case, it goes without saying that both ends of the spacer 4 should not protrude beyond the end of the outer insulating layer aυ. Thereafter, the conductor with the m insulation was placed in a vacuum impregnation tank, and epoxy resin of 1 poise, which had been reduced in pressure to 0.5 Torr or less, was poured into the tank, and the conductor was immersed in the resin. /cIJP G pressure was applied to the resin for a predetermined period of time. Incidentally, during this predetermined time, a wire mesh tape (not shown) is wound around the center of the outermost periphery of the insulating layer (2) of the insulated conductor, and changes in the capacitance stitch between the conductor (1) and the wire mesh are observed. Measured against resin pressurization time, curve a in Figure 6
This is the time taken to reach saturation. The conductor whose insulating layer (2) has been impregnated with resin in this way is taken out of the vacuum impregnation tank, a steel plate is placed around it, a heat-shrinkable tube is wound over it, and the conductor is cured by heating to obtain an insulated conductor.

Next, the effect will be explained.

If the insulating spacer Ql is not used, wrap a wire mesh tape around the center of the outermost periphery of the insulating layer (2) and measure the change in capacitance between the conductor (1) and the wire mesh with respect to the resin pressurization time. , the time until saturation is calculated as shown in the curve in Figure 6.
It takes several times as much time as in the case of curve a of this embodiment. Therefore, it is clear that according to the manufacturing method of this example, the resin can be reliably impregnated in a short period of time and is economically viable. Then, the inner insulating layer (9) is made into 5 layers, and the outer insulating layer (Qll) is made into 25 layers.
The reason for the layers is as follows.

That is, when the impregnation test was repeated by changing the position of the spacer (II) and the number of layers of insulating tape, in Fig. 7, the impregnation from the direction of the arrow indicated that the impregnation could be reached from the direction of the arrow A. The ratio of the spacer (11 From the side passage Q3 (see Figure 45), impregnation is carried out in the direction of the arrow from the outside to the inside.Therefore, if the spacer OI is positioned at 3N/10 layers or less from the inside, the inner insulation It was found that the resin impregnation of the inner part of the outer layer 1-(9) and the outer 1 edge layer 0υ was reliably carried out.

When impregnating the entire insulating layer (2) of the insulation layer C, it is a necessary condition to ensure that the inner layer is more impregnated than the outer layer in order to prevent deterioration due to high impurities on the inner side. Therefore, 3
The condition is that the value is 2N/7 or less, which is slightly smaller than N/10. In addition, if spacer a [is provided on conductor +1), the insulating layer (2) will easily peel off from the 4th body (1) due to thermal stress caused by the difference in thermal expansion coefficient with the conductor (1). When the 4th field is located directly above the highest conductor ('ill), it is easy to see the deterioration of the first edge layer (2), so it is necessary to
At least one layer must be provided with an inner insulating layer (9) (Q0 In Example 1, the total number of insulating layers is 30, so the integer is taken to be 8 layers, and one layer is provided as an inner insulating layer. It is necessary to have layer (9), and it is appropriate to have five layers.

Further, the reason why the insulating spacer OI is arranged approximately at the center in the width direction of the conductor (1) is that the electric field is highest at the corners of the conductor and the conductor is easily deteriorated. In general, the width of the insulating spacer a1 is 315 mm or less, preferably about half the width of the conductor (1), from the viewpoint of impregnability and deterioration resistance.

In addition, in FIG. 5, the arrangement of the insulating spacer O1 is similar to that of the conductor (1
), but it may be provided on four sides including the two narrow sides. Also, insulating spacer (
11 does not have to protrude from the end of the inner insulating layer (9), it is sufficient that it at least protrudes from the end of the outer insulating layer Qυ.

Embodiment 2 A second embodiment shown in FIGS. 8 and 9 uses a turbine generator 4.
This is an insulated conductor used as a half coil for machines. Core wire (3
) has a water hole I and an insulating coating (4) (5)
are bundled to form a conductor +1), but the inner insulating layer (9
) and the wire (5), the gap (6) created between the mutual corners of the conductor (1) is caused by the leakage of the clip a of the water pipe and the silver between the core wire (3) and the conductor (1) near both ends. Filled with flowing silver solder during brazing. Therefore, one layer of the same insulating tape as in Example 1 was wound twice four times to form a four-layer inner insulating layer +9), and a part of the layer at the end was wound up to the top of the clip I. A mica tape having the same thickness as the insulating tape described in Example 1, 24 mm, and width 32 mm was placed on the wide (68 mm) side of the conductor (1) so as to be located approximately at the center of the conductor (1). Tape t-4 is stacked and arranged as an insulating spacer OI, with both ends protruding above clip 04). The same insulation tape t″l as the inner insulation layer + 9) on the outer periphery
/ One outer edge j-aυ of the C20 layer was formed by double winding 20 times. Both ends of the four-edge spacer Q1 are connected to the outer insulating layer θ
The fact that it protrudes from both ends of D is also the same as in Example I. Next, in the same manner as in Example 1, the epoxy resin is impregnated with gold under pressure and cured by heating to obtain an insulated conductor for a half coil. Then, an insulating tape is further wound over the clip I to form a protective insulation a5.

Next, the effect will be explained.

The total number of insulating layers N is N=4+20=24. Therefore, since the inner insulating layer (9) has four layers, l and 6
A value between 1 and 2 is appropriate. FIG. 10 shows a comparison of the cumulative frequency distribution characteristics of Δtanδ of the insulated conductor thus obtained and the insulated conductor manufactured by the conventional method without an insulated spacer. Δtanδ is ta at rated magnetic pressure.
It is the difference between nδ and tanδ at (rated voltage −2 kV). It was found that the curve a representing the present example had a smaller Δtan δ and less variation than the curve a representing the conventional one. This is because the insulating spacer OI forms a passage a4 where the resin is impregnated, and the resin is impregnated through this passage aa, so that the resin can be completely impregnated within an economically viable short period of time. It is from.

In addition to mica tape, the present invention also uses polyester or aramid nonwoven felt, glass woven tape, glass rope, and glass aramid board (also known as GA board, a product of Nippon Aroma Co., Ltd.) as an insulating spacer OI. A laminated plate or the like may be used, and mica tape or nonwoven felt, which is compressed during molding and hardening after resin impregnation and is integrated with the inner and outer insulating layers (91, On) of the insulating tape (7), is particularly suitable. In addition, as the insulating tape (7), mica tape, polyester or polyimide film, polyester or aramid nonwoven tape, aramid paper, etc. can be used.For high voltage insulation, both the insulating spacer (11) and the insulating tape (7) are used. Mica tape is preferred because it has excellent partial brazing resistance.As the resin, solvent-free thermosetting resins such as epoxy, polyimide, and polyester are preferred.

〔Effect of the invention〕

As explained above, according to the present invention, the total number N of insulating layers can be reduced to 1.
The inner insulating layer is divided into four inner insulating layers of less than 2N/7 and the remaining number of outer insulating layers, which are located approximately in the center of the conductor between the two edge layers, and extend parallel to the conductor and extend over the entire length in the longitudinal direction. Furthermore, an insulating spacer was interposed so that both ends protruded at least from the outside, beyond the end of the copper layer, and the resin was impregnated and cured, so that the resin could pass not only through the outermost surface but also through the passages formed on both sides of the insulating spacer. Since the resin is impregnated into the inner and outer insulation layers, the insulation layer can be completely impregnated with the resin in an economically reasonable time. In addition, since the insulating spacer is located not directly above the conductor, but between the inner and outer insulating layers, and approximately at the center of the conductor width, the presence of the insulating spacer may cause electrical deterioration, mechanical stress deterioration, etc. to the insulating layer. This is an excellent method for manufacturing insulated conductors that does not have any negative effects.

[Brief explanation of drawings]

1 and 2 are cross-sectional views of insulated conductors manufactured by different conventional methods, FIG. 3 is an explanatory diagram showing the resin impregnation path in the insulating layer of FIG. 2, and FIG. A plan view of an insulated conductor showing a state in the middle of manufacturing in the first embodiment of the method, FIG. 5 is an enlarged cross-sectional view taken along line V-V in FIG. 4, and FIG. A curve diagram showing a comparison of the change in static 4 volume with respect to the resin impregnation time of L18 edge conductors manufactured by the method and the conventional method. FIG. 7 shows the course of resin impregnation in the insulating layer of the first row. Explanatory diagram, FA8 diagram is the second
With examples! ! ! ! 9 is an enlarged cross-sectional view taken along the -1 line in FIG. It is a curve diagram comparing and showing the cumulative frequency distribution of Δtanδ of manufactured insulated conductors. 1 - Conductor 2... Insulating layer 7 - Insulating tape 9-Inner insulating layer 1 ()... Insulating spacer 11... Outer Insulation 1 - Agent Patent attorney Inoue - Male @ Figure 1 Figure 2 Figure 3 □! Figure 10 h 44-

Claims (3)

[Claims] (1) In a method for manufacturing an insulated conductor, in which multiple insulating layers are formed on an electrical conductor by winding insulating tape, and the insulating layer is impregnated with resin and cured, when the total number of insulating layers is N, the total insulation II number is divided into an integer number of 1 or more and less than 2N/7 and an outer insulating layer of the remaining number, and is located approximately in the center of the conductor between both insulating layers, parallel to the conductor, and has a total length in the longitudinal direction. A method for manufacturing an insulated conductor, which comprises impregnating and curing a resin with an insulating spacer interposed so that both the ferrules extend over the outer insulating layer and protrude from at least the ends of the outer insulating layer. (2) The method for manufacturing an insulated conductor according to claim 1, wherein the width of the insulating spacer is 375 times or less the width of the conductor. (3) The method for manufacturing an insulated conductor according to claim 1 or 2, wherein the insulating spacer uses mica tape.