JP2698937B2 - Ceramic coated heat-resistant insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a ceramic-coated heat-resistant insulated wire having a coating layer made of a ceramic material formed on a conductor.

[Prior art]

Conventionally, as shown in a sectional view of FIG. 3, a ceramic-coated heat-resistant insulated wire in which a conductor 1 is provided with a coating layer 2 made of a ceramic material having a substantially uniform particle size as shown in a sectional view of FIG. It has been known. In such a ceramics-coated heat-resistant insulated wire, the flexibility is reduced by coating the ceramics. For this reason, in order to improve flexibility, various measures have been taken, such as lowering the heat treatment temperature or reducing the layer thickness.

[Problems to be solved by the invention]

However, if the heat treatment temperature of the ceramics is simply lowered to improve the flexibility, the hardness decreases as is apparent from the measurement results shown in Table 1 (conventional product numbers 3, 5, 8, 1).
0) In addition, when the layer thickness is reduced, there is a problem that heat resistance and insulation are reduced (conventional product numbers 1 and 6). Further, when the ceramic-coated heat-resistant insulated wire as shown in FIG. 3 is bent as shown in FIG. 4, the movement distance between the particles of the coating layer 2 increases from the inside of the bend to the outside of the bend. However, in the structure shown in FIG. 3, since the particle size of the ceramic material of the coating layer 2 is substantially uniform throughout the entire layer, the movement distance between the particles becomes larger than the allowable gap between the particles. There is a problem that sufficient flexibility cannot be obtained in the located portion, and a crack 3 is generated as shown in FIG. An object of the present invention is to provide a ceramic-coated heat-resistant insulated wire having sufficient flexibility while maintaining heat resistance and insulation.

[Means for Solving the Problems]

The ceramic-coated heat-resistant insulated wire according to claim 1, wherein a coating layer of the ceramic-coated heat-resistant insulated wire formed by forming a coating layer made of a ceramic material on a conductor is formed on a conductor.
A ceramic material mixed in the first coating layer, wherein the ceramic material mixed in the second coating layer has a two-layer structure of a coating layer formed on the first coating layer and a second coating layer formed on the first coating layer. Is made of a ceramic material having a particle size larger than the particle size. In the ceramic-coated heat-resistant insulated wire according to the second aspect, the first coating layer and the second coating layer each have a thickness of 20 to 30 μm.

[Action]

According to the above configuration, when the electric wire is bent in an arc shape, a tensile force acts in a direction to separate the particle interval of the ceramic material outside the bend, but the particle size of the ceramic material located outside the bend is large. Since the gap formed between the particles of the ceramic material and the particles of the ceramic material is large, there is a tolerance for a tensile force, and cracks are unlikely to occur. In addition, a compressive force acts in the direction of decreasing the particle interval inside the bend, but since the ceramic material has a large particle diameter, the compressive force is reduced by a gap formed between the ceramic material particles and the ceramic material particles. Therefore, the coating layer does not peel off from the conductor inside the bend.

【Example】

Hereinafter, the ceramic-coated heat-resistant insulated wire of the present invention will be described based on the illustrated embodiment. FIG. 1 is a sectional view showing an embodiment of the present invention. In the figure, 1 is a conductor, 2a is a first coating layer formed of a ceramic material having a predetermined particle size formed on an upper layer of the conductor 1,
Reference numeral 4a denotes a second coating layer formed on the first coating layer 2a and made of a ceramic material having a particle size larger than the predetermined particle size. According to such a structure, when the electric wire is bent in an arc shape, as shown in FIG. 2, the second coating layer 4a located outside the bend pulls the ceramic material in the direction of increasing the particle interval. The force acts, however, in the second coating layer 4a outside of the bend, the particle size of the ceramic material is large, and the gap allowable between the particles of the ceramic material with respect to the tensile force is large. For this reason,
Cracks hardly occur in the second coating layer 4a. Also, the second coating layer 4a located inside the bend
In this case, the compression of the ceramic material in the direction of reducing the particle gap works. However, the second coating layer 4a inside the bend
In this case, since the particle size of the ceramic material is large, the gap between the particles of the ceramic material is large, and the gap between the particles reduces the compressive force applied inside the bend due to bending.
Therefore, the second coating layer 4a does not peel off inside the bend. Table 2 shows that the particle size of the first coating layer 2a was 0.7
μm, the particle size of the second coating layer 4a is 11 μm, and the thickness of these coatings 2a, 4a is 20-30 μm, 50 μm.
It shows various test results when m and 80 μm were changed. According to Table 2, even when the heat treatment temperature is as high as 120 ° C., the thickness of the first and second coating layers 2a and 4a is 20 to 30.
If it is μm, the insulation, heat resistance and hardness are the same as those of the prior art, and the flexibility is satisfied. That is, no cracks were generated even when the wire was bent under the same conditions as those of the conventional structure shown in Table 1. Further, with respect to insulation and heat resistance, performance equivalent to that of the conventional product having a layer thickness of 100 μm is obtained. this is,
It is considered that the first coating layer 2a functions as a barrier layer. Note that the particle size of the coating layers 2a and 4a is not limited to the above-described embodiment.

【The invention's effect】

According to the first aspect of the present invention, the coating layer of the ceramic-coated heat-resistant insulated wire formed by forming a coating layer made of a ceramic material on the conductor is formed on the conductor by the first coating layer and the first coating layer. 1
A second coating layer formed on the first coating layer, wherein the ceramic material mixed into the second coating layer has a particle size larger than the particle size of the ceramic material mixed into the first coating layer. The second coating layer has an allowable force against tensile force and a relaxing force against compressive force. When the electric wire is bent in an arc shape, the tensile force acts on the coating layer outside the bend. However, even if a compressive force acts on the inside of the bend to reduce the particle interval, the compressive force is reduced, and the coating layer can be hardly peeled off from the conductor. According to the invention described in claim 2, the thickness of the first coating layer and the thickness of the second coating layer are each set to 20 to 30.
Since the thickness is set to μm, sufficient flexibility can be obtained while maintaining the heat resistance and the insulating property as before.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a ceramics coated heat-resistant insulated wire of the present invention, FIG. 2 is a cross-sectional view showing a state where the ceramics coated heat-resistant insulated wire of FIG. 1 is bent,
FIG. 3 is a cross-sectional view showing the structure of a conventional ceramic-coated heat-resistant insulated wire, and FIG. 4 is a cross-sectional view showing a state in which the conventional ceramic-coated heat-resistant insulated wire is bent. DESCRIPTION OF SYMBOLS 1 ... Conductor 2 ... Coating layer 2a ... 1st coating layer 3 ... Crack 4a ... 2nd coating layer

Claims (2)

(57) [Claims] 1. A ceramic-coated heat-resistant insulated wire having a coating layer made of a ceramic material formed on an upper layer of a conductor, wherein the coating layer comprises a first coating layer formed on the conductor and the first coating layer. A second coating layer formed on the first coating layer, wherein the ceramic material mixed into the second coating layer is a ceramic material having a particle diameter larger than the particle diameter of the ceramic material mixed into the first coating layer. A ceramic-coated heat-resistant insulated wire characterized by comprising: 2. The ceramic-coated heat-resistant insulated wire according to claim 1, wherein said first coating layer and said second coating layer each have a thickness of 20 to 30 μm.