JPH10134642A - Multilayer insulated wire and transformer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer insulated wire which satisfies a demand for improvement in heat resistance and has required characteristics such as thermal shock resistance and slipperiness required for a coil application and a transformer using the same. . SOLUTION: In a multilayer insulated wire having two or more insulating layers on a conductor, the outermost layer is made of an extruded coating layer of a polyamide resin, and the other layers are made of an extruded coating layer of polyether sulfone. Provided are a multilayer insulated wire and a transformer using the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer insulated wire having excellent heat resistance and useful as a winding and a lead wire of a transformer to be incorporated in electric or electronic equipment, and a transformer using the same.

[0002]

2. Description of the Related Art The structure of a transformer conforms to the IEC standard (Internat
ional Electrotechnical Communication Standard) Pu
It is specified by blication 950, 65, 335, 601 and the like. 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 enamels between the primary winding and the secondary winding, including auxiliary insulation, are included.
The insulating layer of the layer is formed or the thickness of the insulating layer is 0.4 mm or more. For example, the creepage distance between the primary winding and the secondary winding is 5 mm or more, although it depends on the applied voltage. In addition, it is specified that a voltage of 3000 V is applied to the primary side and the secondary side for one minute or more.

[0003] Therefore, in the current mainstream transformer,
A cross-sectional structure as illustrated in FIG. 1 is employed. That is, a flanged bobbin 2 is fitted into the ferrite core 1, and enamel-coated 1 is provided in a state where insulating barriers 3 for securing a creepage distance are disposed on both sides of the periphery of the bobbin 2.
After the secondary winding 4 is wound, at least three layers of insulating tape 5 are wound on the primary winding 4 and the insulating barrier 3 for securing a creepage distance is arranged on the insulating tape. And a secondary winding 6 similarly wound with enamel.

In recent years, instead of the transformer having the cross-sectional structure shown in FIG. 1, a transformer having a structure not including the insulating barrier 3 and the insulating tape layer 5 as shown in FIG. 2 has begun to appear. This transformer has advantages that the whole can be reduced in size as compared with the transformer having the structure of FIG. 1 and that the winding work of the insulating tape can be omitted.

When the transformer shown in FIG. 2 is manufactured, the primary winding 4 and the secondary winding 6 used are provided with three insulating layers 4b around one or both conductors 4a (6a).
It is necessary that (6b), 4c (6c), and 4d (6d) are formed, and that delamination between these insulating layers is possible in relation to the IEC standard.

As such a winding, an insulating tape is wound around a conductor to form a first insulating layer, and an insulating tape is further wound thereon to form a second insulating layer. It is known that an insulating layer having a three-layer structure in which insulating layers of a layer are sequentially formed and the layers are separated from each other is formed. Further, there is known a winding in which a fluororesin is sequentially extruded on the outer periphery of a conductor which is enameled with polyurethane, and an extruded coating layer having a three-layer structure is used as an insulating layer as a whole (Japanese Utility Model Application Laid-Open No. 3-5).
No. 6112).

[0007]

However, in the case of the former winding, the winding of the insulating tape is indispensable, so that the productivity is remarkably reduced and the production cost is increased. In the case of (1), the insulating layer is formed of a fluorine-based resin, and thus has an advantage of good heat resistance. On the other hand, however, the insulating layer lacks reliability because of poor adhesion between layers. There is a problem.

In order to solve such problems, both the first and second insulating layers are formed by extrusion coating of a polyester resin, and the outermost third insulating layer is formed of a polyamide resin. (Japanese Patent Laid-Open No. 6-223634).

However, recently, there is a strong demand for downsizing of the transformer, and the heat generation of the transformer due to the downsizing has become a problem. Many have appeared. In order to meet such demands, it is necessary to further improve the heat resistance and to develop an insulated wire having a heat resistance of a heat class B class (130 ° C.).

SUMMARY OF THE INVENTION An object of the present invention is to provide a three-layer insulated wire which satisfies the demand for improvement in heat resistance and also has the required properties such as thermal shock resistance and slipperiness required for coil applications and a transformer using the same. And

[0011]

In order to achieve the above-mentioned object, many heat-resistant resins (for example, polycarbonate,
Polyarylate, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, etc.), as well as the above-mentioned required properties, as well as thin-wall extrusion, productivity, flexibility, etc. It was confirmed through experiments that the object could be achieved by using a polyethersulfone as a main component and combining it with a polyamide resin, and completed the present invention.

That is, in the present invention, two conductors
In a multilayer insulated wire having at least one insulating layer, the outermost layer of the multilayer insulated wire is made of an extruded coating layer of a polyamide resin, and the other layers are made of an extruded coating layer of polyether sulfone. Is provided. Further, a transformer using the multilayer insulated wire is provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the multilayer insulated wire of the present invention, the insulating layers other than the outermost layer are formed by extrusion coating layers of polyethersulfone.

The polyether sulfone used in the present invention is
It is a resin having any one of the repeating units (a) to (c) shown in Chemical Formula 1.

[0015]

Embedded image

As the polyether sulfone, a commercially available product can be used, and Victrex 36 manufactured by Sumitomo Chemical Co., Ltd. is used.
00G, 4100G and Amoco's Radel A-1
00, A-200, A-300 and the like can be used.

In the multilayer insulated wire of the present invention, not all of the multilayer insulating layers are formed of polyethersulfone. The use of polyethersulfone as the insulating layer not only improves heat resistance, but also meets many requirements such as thin-wall extrusion moldability.However, when all insulating layers are formed of polyethersulfone, the thermal shock characteristics are greatly reduced. Then, cracks in the outer layer reach the conductor.

In the multilayer insulated wire of the present invention, polyether sulfone is used for the insulating layers other than the outermost layer, and polyamide resin is used for the outermost layer in order to ensure heat resistance.
By forming the polyamide resin layer as the outermost layer, it is possible to prevent cracks due to thermal shock, which is a drawback of polyether sulfone, to prevent a decrease in thermal shock characteristics and to improve coil workability. be able to.

The polyamide resin preferably used as the outermost insulating layer in the present invention includes nylon 6,6.
(A-125 manufactured by Unitika, Amilan CM-3001 manufactured by Toray Industries, Inc.), nylon 4,6 (F-5000 manufactured by Unitika, C2000 manufactured by Teijin Limited), nylon 6, T (Mitsui Oil Arlen AE-420 manufactured by Chemical Co., Ltd.
0) and the like.

The polyether sulfone or polyamide resin used for the insulating layer in the multilayer insulated wire of the present invention may contain a coloring agent, an antioxidant, and the like, if necessary.

In the multilayer insulated wire of the present invention, the outer periphery of a conductor is extrusion-coated with a first insulating layer having a desired thickness, and then the outer periphery of the first insulating layer is covered with a second insulating layer having a desired thickness. It is manufactured by extrusion-coating the insulating layer sequentially by the method of extrusion-coating the insulating layer.

[0022]

【Example】

(Examples 1 to 4 and Comparative Examples 1 to 4) The material shown in Table 1 was sequentially extruded on a soft copper wire having a wire diameter of 0.4 mm to a thickness of 30 μm to form an insulating layer, and a thickness of 60 μm or 90 μm was formed. Was produced. In addition,
The temperature of the die head during extrusion coating was 370 ° C for polyethersulfone, 280 ° C for 6,6 nylon,
The temperature was set to 300 ° C. for 6 nylon and 340 ° C. for 6, T nylon.

The following tests were performed on the insulated wires of Examples 1 to 4 and Comparative Examples 1 to 4 in terms of heat resistance, thermal shock resistance, and slip property. Table 1 shows the test results.

Heat resistance: (based on IEC Publication 172) A sample was prepared by twisting two of the obtained multi-layer insulated wires so that a tension of 27.0 MPa was applied, and a predetermined 3
Evaluation was performed under temperature conditions. The check voltage was 1.44 kV for an insulated wire having an insulating layer thickness of 60 μm, and 90
In the case of μm, 2.16 kV was applied for 1 second. From this result, it was confirmed whether or not the insulated wire had heat resistance class B (130 ° C.).

Thermal shock resistance: (IEC Publication 851-
(Based on 6.3.1) A sample was prepared by winding an insulated wire around a 10-fold diameter mandrel for 10 turns so that a tension of 118 MPa was applied. After heating the sample at 225 ° C. for 30 minutes, the appearance of the insulated wire was observed, and the presence or absence of appearance defects such as cracks was examined. An insulated wire in which even one crack was generated was determined to have poor thermal shock resistance.

Slipperiness: FIG. 3 is an explanatory view of an apparatus for measuring a coefficient of friction. As shown in FIG. 3A, the insulated wires 9 are fixed in two rows, and a slider 8 around which the insulated wires 7 are wound is arranged perpendicular to the insulated wires 9.
As shown in (b), a load 10 was applied to the slider 8, and the coefficient of friction between the insulated wires was calculated. If the coefficient of friction was less than 0.1, it was determined that the sliding property was good, and if it was 0.1 or more, it was determined to be poor.

[0027]

[Table 1]

As shown in Examples 1 to 4, a multi-layer insulated wire having a polyether sulfone as an insulating layer and a polyamide resin as an outermost insulating layer has a heat resistance class B class (130 ° C.).
And has sufficient thermal shock resistance and slipperiness as an insulated wire. On the other hand, the insulated wires of Comparative Examples 1 to 4 had an insulating layer formed of polyethersulfone and a polyamide resin, but the combination was inappropriate, so that the heat resistance and thermal shock resistance required for the insulated wires were inadequate. , One of the slip properties is inferior.

[0029]

According to the multilayer insulated wire of the present invention, since the insulating layer is formed by extruding a polyether sulfone and a polyamide resin in a specific order, it satisfies the demand for improvement in heat resistance for use, and is used in coil applications. It has all of the required properties such as thermal shock resistance and slipperiness required as a product. Further, the transformer using the multilayer insulated wire can reduce the coil space factor and contribute to space saving.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view illustrating an example of a transformer having a structure in which a three-layer insulated wire is wound.

FIG. 3 is an explanatory diagram illustrating an apparatus for measuring a friction coefficient.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ferrite 2 Bobbin 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 7 Multilayer insulated wire 8 Slider 9 Multilayer insulated wire 10 Load

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Shigeo Yamaguchi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd.

Claims (2)

[Claims] 1. A multi-layer insulated wire having two or more insulating layers on a conductor, wherein the outermost layer is formed of an extruded coating layer of a polyamide resin, and the other layers are formed of an extruded coating layer of polyether sulfone. A multilayer insulated wire characterized by comprising: 2. A transformer using the multilayer insulated wire according to claim 1.