JPH1021757A - Heat-resistant electric wire and its manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a heat-resistant wire excellent in flexibility and also excellent in insulation properties, and a method of manufacturing the same. SOLUTION: The present invention provides a lead wire 4a made of pure nickel,
A first insulator 5a made of ceramic fiber spirally wound twice around the conductor 4a, and a conductor 4b made of pure nickel;
A second insulator spirally wound around the conductive wire 4b; and a second ceramic fiber braided so as to cover the first insulator 5a and the first insulator 5b. An insulator 6 and a coating material 7 for coating the surface of the second insulator 6 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant electric wire suitable for use as a lead wire or the like in a high-temperature environment and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, for example, various characteristics (temperature, pressure, strain, flow velocity,
Sensors for measuring heat transfer, etc.)
The output signal of this sensor is transmitted to a measuring device via a lead wire. The lead wires are 300
An MI cable that can withstand an environmental temperature of up to 900 ° C. is used.

FIG. 3 shows the structure of the above-mentioned MI cable. FIG. 3A is a partially cutaway plan view showing the configuration of the MI cable, and FIG. 3B is a cross-sectional view taken along line XX ′ shown in FIG. In these figures, reference numeral 1 denotes a protection tube made of stainless steel and has an outer diameter D of 1.0 to 3.2 mm.
Reference numerals 2a and 2b denote conductive wires made of pure nickel housed at regular intervals in the protective tube 1 so as to be substantially parallel to each other. 3
Is an insulator filled in the protective tube 1 so as to cover the periphery of the conductors 2a and 2b.
(Magnesia oxide) is used.

[0004]

The above-mentioned M
The I-cable has the advantage of being excellent in heat resistance, but cannot be easily bent because it is formed of the protective tube 1 made of stainless steel, and therefore can be routed particularly in a narrow place such as in an engine. There was a drawback that it was difficult to remove. Further, in the above-described MI cable, MgO used as the insulator 3 has a disadvantage that, due to its properties, it is likely to absorb moisture, thereby causing insulation deterioration. The present invention has been made under such a background, and an object of the present invention is to provide a heat-resistant electric wire having excellent flexibility and excellent insulating properties, and a method for manufacturing the same.

[0005]

According to a first aspect of the present invention, there is provided a conductive wire (4a), a first insulator (5a) made of ceramic covering the conductive wire (4a), and the first insulator. (5a) a second insulator made of ceramic covering the (6)
And characterized in that:

According to a second aspect of the present invention, in the heat-resistant electric wire according to the first aspect, the first insulator (5a) is formed by spirally winding the bundled ceramic fibers around the conductive wire (4a). The second insulator (6) is characterized in that the bundled ceramic fibers are braided.

According to a third aspect of the present invention, in the heat-resistant electric wire according to the second aspect, the first insulator (5a) is spirally wound around the conductor (4a) in a plurality of layers. It is characterized by the following.

According to a fourth aspect of the present invention, in the heat-resistant electric wire according to any one of the first to third aspects, the second insulator (6) is made of a coating material (7) made of a ceramic material. It is characterized by being coated.

According to a fifth aspect of the present invention, the first insulator (5a) made of a bundled ceramic fiber is connected to a conductor (4).
a) a first step of spirally winding a), a second step of braiding the bundled ceramic fibers so as to cover the first insulator (5a), and the second step. And a third step of heating the heat-resistant electric wire at a high temperature.

According to a sixth aspect of the present invention, in the method for manufacturing a heat-resistant electric wire according to the fifth aspect, in the first step, the ceramic fibers bundled in the first step are connected to the conductive wire (4a).
It is characterized in that it is spirally wound a plurality of times.

According to a seventh aspect of the present invention, in the method for manufacturing a heat-resistant electric wire according to the fifth or sixth aspect, after the third step, the surface of the second insulator (6) is made of a ceramic material. A fourth step of coating with a coating material (7) consisting of:

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a partially cut-away plan view showing a configuration of a heat-resistant electric wire according to an embodiment of the present invention, and FIG. 1B is a sectional view taken along line YY ′ shown in FIG. is there. In these figures, reference numeral 4a denotes a conductive wire made of pure nickel and has a diameter of 0.16 mm. Reference numeral 5a denotes a first insulator made of a bundle of ceramic fibers such as alumina, which is helically wound twice around the conductor 4a. In other words, the conductor 4a shown in FIG. 1B is composed of a first insulator 5a1 of the first turn and a first insulator 5a2 of the second turn further wound around the first insulator 5a1. Covered in.

In FIG. 1A, reference numeral 4b denotes a lead made of pure nickel provided at a fixed distance from the lead 4a. Reference numeral 5b denotes a first insulator having the same configuration as the first insulator 5a, which is helically wound twice around the conductor 4b, and the conductor 4b shown in FIG. It is covered with the first insulator 5b1 of the winding and the first insulator 5b2 of the second winding.

In FIG. 1A, reference numeral 6 denotes a second insulator formed by braiding ceramic fibers bundled together, and covers the first insulator 5a and the first insulator 5b.
In FIG. 1B, a clearance is shown inside, but actually, there is no clearance. The second insulator 6 is coated with a heat-resistant coating material 7 shown in FIG. This coating material 7 serves to smooth and protect the surface of the second insulator 6.

Next, a method of manufacturing the heat-resistant electric wire according to the above-described embodiment will be described with reference to FIG. First, in the first step, the first insulator 5a is spirally wound once on the conductor 4a,
After winding, the first insulator 5a is further spirally wound on the first insulator 5a in a direction opposite to the spiral direction. Similarly, the first insulator 5b is spirally wound twice around the second conductor 4b. Next, in a second step, after the conductive wire 4a and the conductive wire 4b created in the first step are bundled, these are braided with the bundled ceramic fibers and covered with the second insulator 6. Next, in a third step, the one created in the second step is subjected to a heat treatment at about 1000 ° C. for about 1 hour. By this heat treatment, each insulator conforms. Finally, in a fourth step, a coating material 7 made of a ceramic material is applied to the surface of the second insulator 6 and then dried.

Next, the heat-resistant electric wire according to the above-described embodiment is used for measuring strain (30) in an aeronautical gas turbine engine.
FIG. 2 shows an example in which the present invention is applied to a lead wire of 0 to 900 ° C.). In this figure, reference numeral 8 denotes a compressor blade (moving blade) of an aeronautical gas turbine engine. 9 is a strain gauge provided on the compressor blade 8,
Each end is connected to a thin film conductor 10a, 10b sputtered on the surface of the compressor blade 8, respectively. Reference numeral 100 denotes the above-described heat-resistant electric wire, one end of which is fixed to the compressor blade 8 by the fixing clamp 11. The conductor 4a and the conductor 4b of the heat-resistant electric wire 100
Has one end connected to each of the thin film conductors 10a and 10b, while the other end is drawn out of the engine and connected to an input end of a strain measuring device (not shown) via a low-temperature soft cable. It is connected.

According to the heat-resistant electric wire according to the above-described embodiment, since the first insulator 5a and the first insulator 5b are wound twice, an effect that the withstand voltage is improved can be obtained. Approximately 0.5kV for single winding and approximately 1.4kV for double winding). Also,
According to the heat-resistant electric wire according to the above-described embodiment, since the insulator made of the ceramic fiber is used, it is possible to obtain an effect that the flexibility is excellent and the insulation is hardly deteriorated by moisture absorption. Furthermore, the heat-resistant electric wire according to the above-described embodiment can have a smaller diameter (FIG. 1B: DL = 1.2 mm) than the conventional MI cable without lowering the withstand voltage.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and a design change or the like may be made without departing from the gist of the present invention. Even if present, it is included in the present invention. For example, in one embodiment described above, two conductors 4a and two conductors 4b
However, the present invention is not limited to this, and the number of conductive wires may be any. Further, in the above-described embodiment, as an application example of the heat-resistant electric wire, an example in which the heat-resistant electric wire is used for measuring a strain in an aeronautical gas turbine engine has been described. It can be applied to any use. Further, in the above-described embodiment, an example in which ceramic fibers are used as the insulator has been described. However, the winding method and the like may be any method, and instead of ceramic fibers, similar properties may be used. May be replaced by a material having

[0019]

According to the present invention, since ceramics (fibers) are used as the first and second insulators, there is obtained an effect that the flexibility is high and the insulation properties are good. Therefore, an effect that the cable routing work becomes easy and insulation deterioration hardly occurs is obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a heat-resistant electric wire according to an embodiment of the present invention.

FIG. 2 is a diagram showing an application example of a heat-resistant electric wire according to the same embodiment.

FIG. 3 is a diagram showing a configuration of a conventional MI cable.

[Explanation of symbols]

 4a conductive wire 5a first insulator 6 second insulator 7 coating material

Continued on the front page. Kawashima Harima Heavy Industries Co., Ltd. Mizuho Plant

Claims (7)

[Claims] 1. A conductor (4a), a first insulator (5a) made of ceramic covering the conductor (4a), and a second insulator made of ceramic covering the first insulator (5a). (6) A heat-resistant electric wire characterized by comprising: 2. The first insulator (5a) is formed by spirally winding a bundle of ceramic fibers around the conductive wire (4a), and the second insulator (6) is bundled. The heat-resistant electric wire according to claim 1, wherein the ceramic fiber is braided. 3. The heat-resistant electric wire according to claim 2, wherein the first insulator (5a) is spirally wound around the conductor (4a) in a plurality of layers. 4. The heat-resistant material according to claim 1, wherein the surface of the second insulator (6) is coated with a coating material (7) made of a ceramic material. Electrical wire. 5. A first material comprising a bundle of ceramic fibers.
A first step of spirally winding the insulator (5a) around the conductive wire (4a); and bonding the bundled ceramic fibers to the first insulator (5).
a) a step of braiding so as to cover a), and a third step of heat-treating the heat-resistant wire prepared in the second step at a high temperature. . 6. The heat-resistant electric wire according to claim 5, wherein in the first step, the bundled ceramic fibers are spirally wound around the conductive wire (4a) in a plurality of layers. Method. 7. A fourth step of coating the surface of the second insulator (6) with a coating material (7) made of a ceramic material after the third step. The method for producing a heat-resistant electric wire according to claim 5.