JP3369607B2 - Three-layer insulated wire, method of manufacturing the same, and transformer using the three-layer insulated wire - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to an manufacturing method thereof a three-layer insulated wire that is a dielectric layer 3 layers, more particularly,
When immersed in a solder bath, its insulating layer can be removed in a short time and solder can be attached to the conductor, so it has excellent soldering characteristics. In addition, the insulating characteristics of the insulating layer are less likely to deteriorate over time, and it can be used in electrical and electronic equipment. 3-layer insulated wire useful as a winding wire or lead wire for transformers to be taken into
The present invention relates to a transformer using the three-layer insulated wire .

[0002]

2. Description of the Related Art The structure of a transformer is based on the IEC standard (Internat
ional Electrotechnical Communication Standard) Pu
b.950,65,335,601 etc. That is, in these standards, the enamel coating that covers the conductor in the winding is not recognized as an insulating layer, and at least three insulating layers are formed between the primary winding and the secondary winding, or Thickness should be 0.4mm or more, edge distance between primary and secondary windings should be 5mm or more, depending on the applied voltage, and 300 on primary side and secondary side.
It is specified that the device withstands 1 minute or more when 0V is applied.

For this reason, in the transformers that currently occupy the mainstream seat, the cross-sectional structure illustrated in FIG. 1 is adopted. That is, the bobbin 2 with the collar on the ferrite core 1
The primary winding 4 covered with the enamel is wound in a state where the insulating barriers 3 for securing the edge distance are arranged at both ends of the peripheral surface of the bobbin 2 and then the primary winding 4 is wound.
At least three layers of the insulating tape 5 are wound on the insulating tape layer, and the insulating barrier 3 for securing the edge distance is arranged on the insulating tape layer. Then, the secondary winding 6 also coated with the enamel is wound. It is a rotated structure.

By the way, in recent years, as shown in FIG. 2, a transformer having no insulating barrier 3 or insulating tape layer 5 has begun to appear in place of the transformer having the sectional structure shown in FIG. Compared with the transformer of the structure of FIG. 1, this transformer is
It has the advantages that the entire device can be downsized and that the work of winding the insulating tape can be omitted.

In the case of manufacturing the transformer shown in FIG. 2, in the primary winding 4 and the secondary winding 6 used, at least three insulating layers 4b (on the outer circumference of one or both conductors 4a (6a)). 6b), 4c (6c), and 4d (6d) are formed, and it is necessary that the insulating layers can be separated from each other in relation to the IEC standard.

In such a winding, first, an insulating tape is wound around the outer periphery of a conductor to form a first insulating layer, and then an insulating tape is wound on the second insulating layer, It is known that an insulating layer having a three-layer structure is formed in which a third insulating layer is sequentially formed and layers are separated from each other. Further, there is known a winding in which a fluororesin is sequentially extrusion-coated on the outer periphery of a conductor which is enamel-coated with polyurethane, and an extrusion-coated layer having a three-layer structure is used as an insulating layer as a whole.
-56112 publication).

[0007]

However, in the case of the former winding, the winding work of the insulating tape is unavoidable, so that the productivity is remarkably lowered, and therefore the manufacturing cost is increased. In addition, the latter winding has the advantage that it has good heat resistance because the insulating layer is made of fluorine-based resin, but on the other hand, the adhesion between layers is poor, so it has a high reliability as an insulated wire. There is a problem of lack of sex.

Furthermore, since this insulating layer cannot be removed even by dipping it in a solder bath, for example, in the terminal processing performed when connecting an insulated wire to a lead pin of a component,
There is a problem that the insulating layer of the terminal has to be peeled off by a functional means with low reliability. INDUSTRIAL APPLICABILITY The present invention solves the above-mentioned problems in the conventionally known three-layer insulated wire and satisfies the above-mentioned IEC standard. As a matter of course, the insulating layer is easily removed by dipping in a solder bath And a three-layer insulated wire that can be processed and has excellent terminal processability
An object of the present invention is to provide a manufacturing method thereof and a transformer using the three-layer insulated wire .

[0009]

To achieve the above object SUMMARY OF THE INVENTION In the present invention, the three-layer insulated wire consisting of an insulating layer of three-layer cover the surface of the conductor and the conductor,
A resin obtained by blending 5 to 40 parts by weight of an ethylene-based copolymer having a carboxylic acid or a carboxylic acid salt in a side chain with 100 parts by weight of a thermoplastic linear polyester resin for each of the three insulating layers. extrusion coating layer der the admixture is, the
Cut the insulating layer in the longitudinal direction for about 50 cm, and then cut
Make one notch along the entire circumference in the direction
Fix it to the twister and pinch the other end with the chuck of the twister
Hold directly and rotate the chuck in this state to
When twisted, the three insulating layers peel off into each layer.
The rotational speed of the chuck is provided three-layer insulated wire, characterized in der Rukoto than 90 times of time, also, when the extrusion coating of at least one insulating layer is finished, the surface of the extruded covering layer Characterized by cooling below 100 ° C
A method for manufacturing a three- layer insulated wire is provided. Also, these three layers
A transformer using an insulated wire is provided.

[0010] insulating layer before Symbol 3 layer in the three-layer insulated wire of the present invention is the extrusion coating layer described later to the resin blend. The resin mixture, which is a material for each insulating layer, contains a thermoplastic linear polyester resin and an ethylene copolymer, which will be described later, as essential components. Among them, as the thermoplastic linear polyester resin, a resin obtained by an ester reaction of an aromatic dicarboxylic acid or a dicarboxylic acid, a part of which is substituted with an aliphatic dicarboxylic acid, and an aliphatic diol is used. For example, it is possible to polyethylene terephthalate resin (PET), polybutylene terephthalate resin (PBT), and polyethylene naphthenate tallate resin mentioned as a representative example.

Examples of the aromatic dicarboxylic acid used during the synthesis of the thermoplastic linear polyester resin include terephthalic acid, isophthalic acid, terephthaldicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, diphenyl ether carboxylic acid and methyl terephthalate. Acid, methyl isophthalic acid, etc. can be mentioned. Of these, terephthalic acid is particularly preferable.

Examples of the aliphatic dicarboxylic acid substituting a part of the aromatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid and the like. The amount of substitution of these aliphatic dicarboxylic acids is the same as that of aromatic dicarboxylic acids.
It is preferably less than 0 mol%, particularly 20 mol%.
It is preferably less than. On the other hand, examples of the aliphatic diol used in the ester reaction include ethylene glycol, trimethylene glycol, tetramethylene glycol, hexanediol and decanediol. Of these, ethylene glycol and tetramethyl glycol are preferable. Moreover, as the aliphatic diol, a part thereof may be oxyglycol such as polyethylene glycol or polytetramethylene glycol.

The other essential component of the resin mixture, which is the material for each insulating layer, is, for example, an ethylene-based copolymer in which a side chain of polyethylene is bound with a carboxylic acid or a metal salt of a carboxylic acid. This ethylene-based copolymer acts to suppress crystallization of the thermoplastic linear polyester resin described above, thereby suppressing deterioration of the electrical characteristics of the formed insulating layer over time and, at the same time, between the insulating layers. Contributes to ensuring good peelability.

The carboxylic acid to be bonded is, for example,
Examples thereof include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and phthalic acid. Examples of metal salts thereof include Na and Zn. , K, Mg and the like. As such an ethylene-based copolymer, for example, a part of the carboxylic acid of the ethylene-methacrylic acid copolymer is made into a metal salt, and a resin generally called an ionomer (for example, Himilan; trade name, Mitsui Polychemical Co., Ltd. )), An ethylene-acrylic acid copolymer (for example, EAA; trade name, manufactured by Dow Chemical Co.), and an ethylene-based graft polymer having a carboxylic acid in a side chain (for example, Admer; trade name, Mitsui Petrochemical Industry Co., Ltd. ) Made).

In the resin mixture, the blending ratio of the thermoplastic linear polyester resin and the ethylene copolymer is set in the range of 5 to 40 parts by weight with respect to the former 100 parts by weight. If the latter is less than 5 parts by weight,
Although there is no problem in the heat resistance of the formed insulating layer, the effect of suppressing the crystallization of the thermoplastic linear polyester resin becomes small, so that minute cracks occur on the insulating layer surface during coiling, so-called crazing phenomenon frequently occurs. As the insulating layer deteriorates with time, it causes a significant decrease in the dielectric breakdown voltage. If the blending amount is more than 40 parts by weight, the heat resistance of the insulating layer will be significantly deteriorated. The preferable mixing ratio of both is 100 parts by weight of the former and 7 to 25 parts by weight of the latter.

In the three- layer insulated wire of the present invention, the resin mixture described above is extrusion-coated on the outer periphery of the conductor to form the first insulating layer having a desired thickness, and then the first insulating layer is formed. The outer periphery of the resin mixture is extrusion-coated to form a second insulating layer having a desired thickness, and the outer periphery of the second insulating layer is extrusion-coated to form a third layer having a desired thickness. It is manufactured by forming an insulating layer for the eyes. If necessary, another insulating layer may be provided outside the three insulating layers.

At this time, the resin mixture used for each extrusion coating may have the same composition for each layer,
The composition of the components may be changed within the above-mentioned permissible blending ratio range. Further, it is preferable to control the total thickness of the formed three insulating layers to 100 μm or less, and if the thickness of the second insulating layer is made thicker than the thickness of the other insulating layers, IEC standard 950 is applied. The specified electrical characteristics can be easily realized.

Further, when the extrusion coating of each layer is completed, the surface of each extrusion coating layer is cooled to 100 ° C. or lower by a method such as water cooling or air cooling, and then the next extrusion coating layer is formed. Effectively, the peelability between the layers is improved.

[0019]

In three-layer insulated wire the present invention, since none of the three layers insulating layer is formed by extrusion coating method of a resin blend, productivity during production becomes very high. Further, the delamination property is good, and at the time of processing the terminal, direct soldering can be performed. The ethylene-based copolymer serves to suppress crystallization of the polyester resin, which is the base resin, so that the electrical characteristics of the insulating layer are not easily deteriorated.

[0020]

Examples of the invention

Examples 1 to 4 and Comparative Examples 1 to 4 The components shown in Table 1 were kneaded in the indicated proportions (parts by weight) to prepare resin blends for each extrusion coating layer. An annealed copper wire having a wire diameter of 0.6 mm was used as a conductor, and the resin mixture was extrusion-coated on the outer periphery thereof to form each extrusion coating layer with the indicated thickness to produce a three-layer insulated electric wire. In addition, in the case of Example 1, after each extrusion coating was completed, the surface of the formed extrusion coating layer was once water-cooled to 100 ° C., and then the next extrusion coating layer was formed thereon.

Each insulating layer of the electric wire of Comparative Example 3 is formed by winding the indicated polyester film.

[0022]

[Table 1]

With respect to the above seven types of three-layer insulated wires, various characteristics were measured according to the following specifications. Solderability: The temperature of the end of the wire about 40mm is 400 ℃
Immerse in the molten solder, and measure the time (seconds) until the solder adheres to the immersed 30 mm portion. The shorter this time is, the better the solderability is.

Electrical insulation: For each of the two-layer and three-layer coatings immediately after production, a bare copper wire is used on one side according to the two-strand method specified in JISC3003, and the breakdown voltage at that time is measured. . Regarding the three-layer coated electric wire, after leaving it in the atmosphere for one year, the dielectric breakdown voltage was similarly measured by the two-strand method to examine the change with time in the electric insulating property.

Heat resistance: JISC for 3-layer coated wire and bare copper wire
Twist two in accordance with 3003, in that state, the temperature 20
After heat treatment at 0 ° C for 7 days, measure the dielectric breakdown voltage. The larger this value is, the better the heat resistance is. Crazing resistance: After the wire has been left in the atmosphere for 6 months, the wire is aligned and mechanically wound on a coil reel having a diameter of 12 mm, and whether or not crazing has occurred on the wire surface is observed.

Delamination: About 50 cm in the longitudinal direction of the insulating layer
After cutting with a cutter knife over one end, sandwich one end of the electric wire in the mandrel, rotate the mandrel to twist the electric wire, and measure the number of mandrel rotations until each layer of the three insulating layers peels from each other. The smaller this value is, the better the delamination property of the insulating layer is.

The above results are collectively shown in Table 2.

[0028]

[Table 2]

[0029]

As is apparent from the above description, the present invention
The three- layer insulated wire has high productivity during manufacturing because all of the insulating layers are formed by extrusion coating. Also, the insulating layer has solderability, heat resistance, crazing resistance, delamination resistance, and electrical insulation. Is excellent, and the deterioration of characteristics over time is small.
Therefore, its industrial value is extremely large as a transformer winding or lead wire satisfying the IEC standard.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a transformer having a conventional structure.

FIG. 2 is a cross-sectional view showing an example of a transformer having a structure having a three-layer insulated wire as a winding wire.

[Explanation of symbols]

1 Ferrite core 2 bobbins 3 Insulation barrier 4 primary winding 4a conductor 4b, 4c, 4d insulating layer 5 insulating tape 6 secondary winding 6a conductor 6b, 6c, 6d insulating layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01B 13/14 H01B 13/14 Z // B29L 31:34 B29L 31:34 (72) Inventor Mitsuru Inoue 2 Marunouchi, Chiyoda-ku, Tokyo 6-1-1, Furukawa Electric Co., Ltd. (56) Reference JP-A-4-10305 (JP, A) Actual Kaihei 3-110721 (JP, U) (58) Fields investigated (Int.Cl. ⁷⁾ , DB name) H01B 7/02 B29C 47/02 C09D 167/02 C09D 177/00 H01B 3/30 H01B 13/14

Claims (3)

(57) [Claims] 1. A three-layer insulated wire consisting of an insulating layer of three-layer you cover the surface of the conductor and the conductor, the insulating layer of the three layers, both, thermoplastic linear polyester resin 10
To 0 parts by weight, Ri extruded covering layer der resin blend formed by blending the ethylene copolymer 5-40 parts by weight of a carboxylic acid or carboxylic acid salt in the side chain, the longitudinal of said insulating layer
After slicing for about 50 cm in the direction, the entire circumference also in the circumferential direction
Make one notch across and fix one end to the twister
Then, hold the other end straight with a zipper chuck.
In this state, the chuck was rotated and twisted in the longitudinal direction.
When the three insulating layers are separated into the layers,
3 the rotational speed of the jack is characterized in der Rukoto below 90 times
Layer insulated wire. 2. A 3-layer insulation method for producing a wire the insulating layer of the three layers on the surface of the conductor formed by extrusion coating, when the extrusion coating of each layer is completed, the surface of the extruded covering layer 100
A method for producing a three- layer insulated wire, which comprises cooling to below ℃. 3. The use of the three-layer insulated wire according to claim 1.
Characteristic transformer.