JPH09320349A - Superfine self-bonding rectangular insulated wire - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a superfine self-bonding rectangular insulated wire in which an insulating coating layer having a uniform thickness is formed on the outer periphery of a rectangular conductor. A thickness-width ratio is 20 or more and a thickness is 0.5 mm.
In the following ultra-fine self-bonding rectangular insulated wire 1, an oxide film layer 3 having a uniform thickness is formed on the outer periphery of a rectangular conductor 2, and a self-bonding layer 4 is formed on the outer periphery of the oxide film layer 3. is there.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superfine self-bonding rectangular insulated wire, and more particularly to a superfine self-bonding rectangular insulated wire used for a small flat motor coil or the like.

[0002]

2. Description of the Related Art In recent years, miniaturization, weight reduction and high torque have been demanded for capstan motors for AV equipment and the like.

In particular, the tendency is remarkable in those used for video cameras and the like, and the brushless motor has been developed under such circumstances. Further, flat coils have come to be used for stators of brushless motors.

The flat coil is generally constructed by aligning and winding round wires, but recently, in order to further reduce the size, the weight, and the torque, a flat coil in which a superfine rectangular wire is wound in a spiral shape has appeared.

Coil forming is generally performed by hot fusion or alcohol fusion, but coil forming using a self-bonding wire which does not require such a process has also been performed.

By using the ultrafine self-bonding flat insulated wire for the coil, the space factor can be improved and the coil can be easily formed as compared with a general coil using a round wire, and as a result, the flat motor can be manufactured. It is possible to reduce the size or increase the torque.

[0007]

However, the coating of the insulating coating layer of the ultra-fine self-bonding rectangular insulated wire is performed by simply coating and baking the liquid coating on the outer circumference of the conductor with a felt or the like like general enameled wire coating. You cannot paint just by doing.

In a flat coil, generally, in order to improve the space factor, the thickness of the insulating coating layer of the flat conductor is made extremely thin, 0.3 μm or less, and the flat conductor also has a thickness of 0. Since it is as thin as 5 mm or less, it is impossible to form an insulating coating layer having a uniform thickness on the edge portion of the rectangular conductor.

Therefore, as a method for forming a thin insulating coating layer on the outer periphery of the rectangular conductor, an electrodeposition coating method, an electrostatic powder coating method, etc. have been studied and partially put into practical use. However, even with these methods, it is not possible to completely form the insulating coating layer having a uniform thickness on the edge portion of the rectangular conductor. Also,
The painting equipment and painting technology are complicated and difficult, resulting in higher costs.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to solve the above problems and provide a superfine self-bonding rectangular insulated wire in which an insulating coating layer having a uniform thickness is formed on the outer periphery of a rectangular conductor.

[0011]

In order to solve the above-mentioned problems, the invention of claim 1 has a thickness width ratio of 20 or more and a thickness of 0.
In an ultrafine self-bonding flat rectangular insulated wire having a thickness of 5 mm or less, an oxide coating layer having a uniform thickness is formed on the outer periphery of a rectangular conductor, and a self-fusing layer is formed on the outer periphery of the oxide coating layer.

The invention of claim 2 is the ultrafine self-bonding rectangular insulated wire according to claim 1, wherein the thickness of the oxide film layer is 0.3 to 0.8 μm.

The reason for limiting the above numerical range will be described below.

The thickness of the oxide film layer is 0.3 to 0.8 μm.
The reason why it is limited to is that it is difficult to maintain the insulation performance when the thickness of the oxide film layer is thinner than 0.3 μm.
This is because if it is thicker than 0.8 μm, the oxide film becomes brittle and a uniform oxide film cannot be obtained.

According to the above structure, since the oxide film layer having a uniform thickness is formed on the outer periphery of the rectangular conductor and the self-fusion layer is formed on the outer periphery of the oxide film layer, sufficient insulation is obtained. Moreover, it is possible to obtain an easy and inexpensive ultrafine self-bonding rectangular insulated wire.

[0016]

Embodiments of the present invention will be described below.

By winding the superfine rectangular wire around the coil in a spiral shape, a potential difference of several mV to several hundred mV is not generated between the coil layers, so that the insulating coating layer is formed on the outer periphery of the rectangular conductor with a uniform thickness. If so, the withstand voltage itself of the insulating coating layer is about several volts.

Therefore, as a result of intensive studies, the present inventors oxidize copper, which is a rectangular conductor, form a very thin copper oxide film layer on the surface, and use this as an insulating film layer. It has been found that an insulating coating layer having a uniform thickness can be obtained on the outer periphery of a flat conductor.

A cross section of the ultrafine self-bonding rectangular insulated wire of the present invention is shown in FIG. In addition, FIG. 1B shows an enlarged view of a main part (end portion) in FIG.

As shown in FIGS. 1 (a) and 1 (b), the ultrafine self-bonding rectangular insulated wire 1 of the present invention has a width-thickness ratio of 20.
As described above, the oxide film layer 3 having a uniform thickness is formed on the outer periphery of the flat rectangular conductor 2 having a thickness of 0.5 mm or less even in the flat portion 2a, the R portion 2b, and the edge portion 2c. The self-fusion layer 4 is formed on the outer circumference.

The method of forming the oxide film layer 3 is not particularly limited, but the ultrafine self-bonding rectangular insulated wire 1 of the present invention is used.
Is a self-fusion line in which a self-fusion layer 4 is formed on the oxide layer 3, and the oxide layer 3 is in the same furnace as the self-fusion layer 4 formed by an enamel coating machine (not shown). Therefore, forced heating in oxygen is the simplest and is particularly desirable.

Superfine self-bonding rectangular insulated wire 1 of the present invention
Has a thickness of 0.3 to 0.8 on the outer circumference of the rectangular conductor 2 by passing the rectangular conductor 2 through the heating furnace once to several times.
The oxide film layer 3 is formed so as to have a thickness of μm, and then the self-bonding layer 4 is formed on the outer periphery of the oxide film layer 3 in the same step.

Since the oxide film layer 3 is very thin and may be destroyed by a slight mechanical impact, the oxide film layer 3 is protected from mechanical impact by forming the self-fusing layer 4 on the outer periphery thereof. To do.

The dielectric strength of the oxide film layer 3 is inferior to that of the conventional insulating film layer made of an organic insulating material, but the flat conductor 2
Since it is formed with a uniform thickness on the outer periphery of the, it is an excellent insulating coating layer with fewer defects than electrodeposition / powder coating in this application.

Needless to say, an insulating coating layer may be further formed on the outer periphery of the oxide coating layer 3 by electrodeposition coating or the like, and then the self-fusing layer 4 may be formed on the outer periphery of the insulating coating layer. Thereby, the withstand voltage can be further increased.

[0026]

【Example】

(Example 1) An ultra-fine rectangular copper wire having a thickness of 25 μm and a width of 500 μm was used, a furnace length was 3 m, a furnace temperature was 250 ° C., and a linear velocity was 90 m / m.
It is introduced into an in-name enamel coating machine and is air-passed for 5 passes to form an oxide film layer having a thickness of 0.4 μm on the outer periphery of the ultrafine rectangular copper wire. After that, apply polyamide-based fusion paint to the outer periphery of the oxide film layer of the ultra-fine rectangular copper wire with a felt.
The baking is repeated for 3 passes to form a self-bonding layer having a thickness of 2 μm to produce a superfine self-bonding rectangular insulated wire.

Comparative Example 1 Thickness 25 μm, Width 500 μm
Introducing the ultra-fine rectangular copper wire into an enamel coating machine with a felt coating method similar to general round braided enamel wire coating, and repeating the application and baking of polyurethane-based insulating paint for 6 passes, to the outer periphery of the ultra-fine rectangular copper wire. A polyurethane insulating layer (insulating coating layer) having a thickness of 2 μm is formed. After that, coating and baking of the polyamide-based fusion paint is repeated on the outer periphery of the polyurethane insulation layer of the ultra-fine rectangular copper wire for 3 passes to form a self-fusing layer with a thickness of 2 μm to produce an ultra-fine self-fusing rectangular insulated wire. To do.

Comparative Example 2 Thickness 25 μm, Width 500 μm
2 μm thick acrylic insulation layer (insulating coating layer) on the outer circumference of the ultra-fine rectangular copper wire after applying an acrylic emulsion type paint to the ultra-fine rectangular copper wire by electrodeposition
To form After that, the ultra-fine rectangular copper wire was introduced into an enamel coating machine with a felt coating method similar to general round braided enamel wire coating, and the coating and baking of polyamide-based fusion paint was applied to the outer periphery of the acrylic insulating layer in 3 passes. Repeat, thickness 2μm
To form a superfine self-bonding rectangular insulated wire.

Table 1 shows the specifications and defect characteristics of the ultrafine self-bonding rectangular insulated wires of Example 1 and Comparative Examples 1 and 2.

[0030]

[Table 1]

Here, the defect characteristics represent the number of pinhole defects per 1 m of ultrafine self-bonding rectangular insulated wire when a voltage of DC 3V is applied.

As shown in Table 1, in the ultrafine self-bonding rectangular insulated wire of Example 1, as shown in FIG. 1, the thickness of the self-bonding layer 4, which is a fusion coating, is flat. 2a and edge portion 2c are 2 μm, and R portion 2b is 0 to 0.5 μm
Although not uniform, the thickness of the oxide film layer 3 as an insulating film is outside the measurement limit even in the micrometer or the laser micrometer of 1 / 10,000, but the flat part 2a, the R part 2b, and the edge part It was uniform at 0.4 μm in both 2c. Further, it can be seen that there is no pinhole defect at the time of applying DC3V, and a uniform insulating film is formed although the withstand voltage is low.

FIG. 2 is an enlarged view of a main part of a cross section of the ultrafine self-bonding rectangular insulated wire of Comparative Example 1. The same members as those in FIG. 1 are denoted by the same reference numerals.

On the other hand, in the ultra-fine self-bonding rectangular insulated wire 11 of Comparative Example 1, as shown in FIG. 2, the self-bonding layer 4 has the same thickness as the flat portion 2a and the flat portion 2a. 2 μm at the edge portion 2c and 0 to 0.5 μm at the R portion 2a
Similarly, the thickness of the polyurethane insulating layer 5a was also 2 μm in the flat portion 2a and the edge portion 2c and 0 to 0.5 μm in the R portion 2b. Further, in the ultrafine self-bonding rectangular insulated electric wire 11, there are numerous pinhole defects when DC3V is applied, which is not good as an insulating coating.

FIG. 3 shows an enlarged view of a main part of a cross section of the ultrafine self-bonding rectangular insulated wire of Comparative Example 2. The same members as those in FIG. 1 are denoted by the same reference numerals.

Ultrafine self-bonding rectangular insulated wire 2 of Comparative Example 2
1, the thickness of the self-bonding layer 4 was the same as in Example 1 and Comparative Example 1 as shown in FIG.
And 2 μm at the edge portion 2c and 0 to 0.5 μ at the R portion 2a
m was not uniform. Acrylic insulation layer 5 which is an insulation film
The thickness of b appears to be substantially uniform as seen in the figure (actually the flat portion 2a and the edge portion 2c).
2 μm at the edge portion, 0 to 1.5 μm at the R portion 2b)
There is a minute defect in the acrylic insulating layer 5b near c, and D
There are 8 pinhole defects / m when C3V is applied, and pinhole defects cannot be eliminated.

The ultrafine self-bonding rectangular insulated wire of the present invention is
Since the oxide film layer, which is an insulating film, is very thin, it is suitable for downsizing and high torque of the flat motor.

Further, the ultrafine self-bonding rectangular insulated wire of the present invention may be used for a cable having a small line voltage, which is particularly required to be downsized.

[0039]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) Since an oxide film layer is formed as an insulating film with a uniform thickness on the outer periphery of a flat conductor, a superfine self-bonding flat insulated wire with no defects or very few defects is provided although the dielectric strength is low. Obtainable.

(2) Since the oxide film layer can be easily formed in the same step as the self-bonding layer, a superfine self-bonding rectangular insulated wire can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a superfine self-bonding rectangular insulated wire according to the present invention.

FIG. 2 is an enlarged view of a main part of a cross section of a superfine self-bonding rectangular insulated wire of Comparative Example 1.

FIG. 3 is an enlarged view of a main part of a cross section of a superfine self-bonding rectangular insulated wire of Comparative Example 2.

[Explanation of symbols]

 1 Ultrafine self-fusing flat insulated wire 2 Flat conductor 2a Flat part 2b R part 2c Edge part 3 Oxide film layer 4 Self-fusion layer 5a Polyurethane insulation layer (insulation film layer) 5b Acrylic insulation layer (insulation film layer)

Claims (2)

[Claims] 1. A thickness-width ratio of 20 or more and a thickness of 0.5 mm
In the following ultra-fine self-bonding rectangular insulated wires, an ultra-fine wire characterized by forming an oxide film layer of uniform thickness on the outer periphery of a rectangular conductor and forming a self-fusion layer on the outer periphery of the oxide film layer. Self-fusing rectangular insulated wire. 2. The oxide film layer has a thickness of 0.3 to 0.
The ultrafine self-bonding rectangular insulated wire according to claim 1, which has a thickness of 8 μm.