JPS6039933Y2 - insulated wire - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an insulated wire with improved electrical properties such as withstand voltage and dielectric properties.

More specifically, the present invention relates to an insulated wire in which an insulating layer is formed by combining an insulating paper tape and a plastic tape and winding them under certain conditions.

In recent years, with the advent of ultra-high voltage transformers and the like, there has been a demand for materials that have a simple structure as insulators and have improved electrical properties such as withstand voltage and dielectric properties over conventional ones.

In particular, in the case of transformers, etc., there is a demand for flat wires that have a good space factor and can be wound without gaps, and that satisfy the electrical characteristics described above.

Therefore, the inventors of the present invention conducted various experiments in search of an insulated wire that satisfies these conditions.

As a result, we have found that it is preferable to combine an insulating paper tape and a plastic tape and wrap them under certain conditions to form an insulating layer around the conductor, as described below.

The present invention was developed based on these results.

As mentioned above, the feature is that an insulating paper tape and a plastic tape are combined and wrapped around the conductor under certain conditions to form an insulating layer.

As a result, the advantages of insulating paper tape and the advantages of plastic tape are combined, and it is possible to provide a tape with excellent electrical properties such as withstand voltage and dielectric properties with a simple structure.

In particular, in the case of the present invention, each tape is simply rolled up;
It is not complicated to integrate like a laminate structure, so it is economical and can be used in places where strong forces such as bending stress are not applied, such as transformers, which are not moved once they are set. It is useful for many purposes.

Hereinafter, the specific configuration of the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the insulated wire of the present invention with the end partially peeled off, and FIG. 2 is a longitudinal sectional view thereof.

In the figure, 1 is a rectangular wire conductor, and an insulating paper tape 2 is wrapped just above this conductor, and on top of this is the above-mentioned insulating paper tape 2 and a plastic tape 3 having a dielectric constant of 2.5 or less and a thickness of 100μ or less. A combination of the two is rolled up, and furthermore, an insulating paper tape 2 is wrapped around the outermost layer on top of this.

At this time, it is preferable that the plastic tapes 3 are not wound adjacently so that the top and bottom overlap.

However, even if two or more layers of plastic tapes 3 are adjacent to each other, it is preferable that the total thickness of the polymerized tapes is 100 μm or less and that the tapes are wound with the same width.

Also, the plastic tape 3 is wound with a gap with a slight gap, and the gear width 4 is ITI.
It shall be less than or equal to rIIL.

These conditions have been clarified through various experiments conducted by the present inventors.

The reason why the insulating paper tape was wrapped directly above the conductor was because the presence of the plastic tape layer would lower the withstand voltage.

The reason for this is that homogeneous materials such as plastic do not have much of an effect on preventing damage from progressing from the conductor side, whereas paper has minute voids that prevent the progress of the damage and disperse it. This is thought to be because it has an effect.

The reason why the thickness of the plastic tape layer inside the insulating layer is set to 100 μm or less is that if the thickness of the layer exceeds 100 μm, the effect of improving the withstand voltage will not appear.

The reason for this is thought to be that plastic has a small effect of inhibiting the progression of fracture, so as the thickness of the plastic layer increases, the progression of fracture becomes more severe, leading to a decrease in withstand voltage.

Therefore, it is necessary to use a plastic tape with a thickness of 100 μm or less, and when two or more plastic tapes are stacked adjacently on one plastic tape layer, the total thickness must be 100 μm or less.

In addition, if the plastic tape is wrapped in an overlapping manner by partially overlapping one side edge, the plastic tape layer will not only become thicker as described above, but also impregnate the insulating oil when it is supplied to the insulating paper tape. Plastic tape needs to be gap-wound.

In this case, if the plastic tape layers overlap one another and are adjacent to each other, the insulating oil will not be sufficiently impregnated between the layers or into the insulating paper tape layer below, which is undesirable.

However, even if two or more plastic tapes are adjacent to each other, if the tape width and gear width are the same, they can be regarded as one tape and are allowed.

Furthermore, the reason why the gear tooth width during gap winding is set to 1rIrIn or less is that if it exceeds 1rIrIrL, the withstand voltage decreases.

The reason for this is thought to be that in oil-immersed insulators, the breakdown electric field force in the oil gap portion is generally weak, and therefore, an increase in the oil gap due to an increase in gear tooth width causes a decrease in withstand voltage.

The reason why we decided to wrap insulating paper tape around the outermost layer of insulation is that if there is plastic tape in this outermost layer, not only will the plastic tape easily attract dirt, but also the plastic will not easily slip on itself. This is because there are problems in use when using an insulated rectangular wire.

Further, when used in a transformer or the like, the withstand voltage between two wires becomes a problem, and if the outermost plastic tape layers come into contact with each other, the plastic becomes thicker, which is undesirable, as described above.

In terms of electrical properties, the plastic used in this invention has a low dielectric constant of 2.5 or less and high withstand voltage, as well as heat resistance, insulating oil resistance, etc. Examples include:

Polypropylene (PP), 4-methylpentene-1 ('r
px), polytetrafluoroethylene (PTFE), tetrafluoroethylenexalfluoropropylene copolymer (FEP), tetrafluoroethylene ethylene copolymer (
FEE).

Other examples include crosslinked plastic materials such as polyethylene (PE), polybutene (PB), and ethylene propylene copolymer (EP) to improve heat resistance and insulating oil resistance.

Furthermore, a material that is a mixture of two or more types of plastics may be used as long as it has excellent electrical properties, heat resistance, and insulating oil resistance.

Examples of the present invention will be described below.

Examples 1 to 9 Table 1 shows 12mm width x 3rIr! Example 1 An insulating layer was provided on an n-thick rectangular wire conductor by combining a 75μ thick insulating paper tape and polypropylene (PP) tapes of various thicknesses.
9 and Comparative Examples 1 to 5 which do not meet the conditions of the present invention are shown, as well as the results of measuring the positive polarity standard impulse breakdown voltage of the insulated rectangular wires made in this way.

Here, the tape width was 15rrr1n width, the insulating paper tape was wrapped in overlap, the polypropylene tape was wound in gaps, and the waist insulating layer was made to fall within the range of 0.9rrvn±10%.

Further, the outermost insulating layer was an insulating paper tape, and an electrode was provided outside the outermost layer to measure the breakdown voltage between the conductors.

As is clear from Table 1 above, when there was a polypropylene tape layer directly above the conductor, there was no improvement in breakdown voltage.

Also, the thickness of the polypropylene tape used is 100μ
If the total thickness exceeds 100 μm or the tape layers are vertically adjacent to each other and the total thickness exceeds 100 μm, the effect of improving the breakdown voltage is small.

Furthermore, it has been found that when the gear width of the gap-wound polypropylene tape exceeds one inch, the breakdown voltage does not improve much.

In the examples shown in Table 1, the number of insulating paper tape layers between the polypropylene tape layers was all one in order to improve the dielectric properties, but even if there are two or more insulating paper tape layers, the effect of improving the breakdown voltage appears.

This phenomenon is not limited to the above-mentioned polypropylene tape, but occurs in all plastic tapes as described above.

In addition, in the examples shown in Table 1, all insulating paper tapes are overlap-wound, but the method of winding the insulating paper tape, regardless of whether it is overlap-wound or gap-wound, is
This shows the effects shown in Table 1.

Examples 10 to 14 By using various plastic tapes with a thickness of 60μ and insulating paper tape with a thickness of 75μ, 12rIr! n width x 3rIr! An insulating layer was provided on a rectangular wire conductor having a thickness of rL.

The tape width was 15 TrrIn, the insulating paper tape was wound in an overlap manner, and the plastic tape was wound in a gap having a gear lug width of 0.1 to 0.2 TIrIn.

The insulation layer immediately above the conductor and the outermost insulation layer was made of insulating paper tape, and the inner layer other than this was made by alternately wrapping plastic tape and insulation paper tape to have an insulation layer thickness of 0.9 mm.

Table 2 shows Examples 10 to 14 constructed in this way, and Comparative Example 6, which is made only of insulating paper tape and does not meet the conditions of the present invention, and also shows an insulated flat rectangle constructed in this way as in the above case. This figure shows the results of measuring the positive polarity standard impulse breakdown voltage of the wire.

The measurement method at this time was the same as in the above-mentioned example.

As is clear from Table 2 above, an improvement in withstand voltage was observed in any case where the plastic had excellent electrical properties such as withstand voltage and dielectric properties.

Incidentally, although the above-mentioned embodiment has been explained using a rectangular wire, the present invention is not limited to this.

As is clear from the above, according to the present invention, insulating paper tape and plastic tape are combined and wrapped under certain conditions to form an insulating layer around the conductor. It is possible to provide an insulated wire with extremely excellent electrical properties such as characteristics.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the insulated wire of the present invention with the end partially peeled off, and FIG. 2 is a longitudinal sectional view taken along the line A--A in FIG. 1. 1... Conductor, 2... Insulating paper tape, 3
...Plastic tape, 4...Gear lub width.

Claims (1)

[Scope of utility model registration request] A combination of insulating paper tape and plastic tape is wrapped around the outer circumference of the conductor to form an insulating layer. At this time, insulating paper tape is wrapped directly above the conductor and on the outermost layer of the insulating layer, and insulating paper tape is wrapped around the inner layer of the insulating layer. , induction factor 2.5
Hereinafter, an insulated wire is characterized in that both plastic tapes having a thickness of 100 μm or less are wound therein, and the plastic tape is wrapped in gap winding, and the gear lug width thereof is ITIrIn or less.