JPH05282924A - Covered conductor - Google Patents

Abstract

(57) [Summary] [Construction] A coated conductor comprising an inner conductor having an insulating coating layer made of a braided ceramic fiber, and an outer conductor having a conductive thin wire formed on the outer periphery of the insulating coating layer. [Effect] Since it can be used in special environments such as high and low temperatures, high vacuum and radiation, which cannot be used with organic materials, it is especially suitable for wiring and signal lines in vacuum equipment and nuclear facilities. It can be used for electric wires and thermocouples used, has flexibility, has good space efficiency, is easy to process terminals, and has a function of avoiding electrical interference from the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated conductor which can be used in a special environment such as high temperature or low temperature, high vacuum or radiation which cannot be used in organic materials, and particularly in vacuum equipment and nuclear facilities. Related to electric wires and thermocouples used for wiring and signal lines, etc., having flexibility, good space efficiency, easy terminal processing, and the function of avoiding electrical interference from the outside Is.

[0002]

2. Description of the Related Art Electric wires and thermocouples used in special environments such as high and low temperatures, high vacuum and radiation are required to have excellent heat resistance and radiation resistance. It is required that the electrical properties and mechanical properties of the insulating coating do not deteriorate and that no gas is released due to thermal decomposition.

Therefore, conventionally, as an electric wire or thermocouple which does not use an organic material as an insulating coating material, a conductor or a thermocouple element wire is simply inserted into an insulator tube or a glass bead, or a conductor is inserted into a stainless steel tube. In addition, MI (Mineral Insulated) cables, etc., which have been filled with ceramic powder to form an insulator, have been used.

When these electric wires or thermocouples are used by being installed in vacuum equipment, nuclear facilities, etc., particularly when they are used for transmission of AC current or DC minute current, AC loss increases,
In order to prevent the electric mutual interference from increasing, it is necessary to cover the central conductor with an insulator and to cover the whole with a conductive material having an earth potential.
The MI cable has such a structure, but there are problems such as poor flexibility, complicated terminal processing, and handling. Further, the conventional one has a problem that the wire diameter is larger than that of the conductor portion and the space efficiency is poor.

[0005]

An electric wire or a thermocouple in which a conductor is inserted in a ceramics tube is inferior in flexibility, and since there is a gap between the conductor and the ceramics tube, the spacer efficiency is poor, and the connection is difficult. Workability is also poor.

Since the MI cable also has a large proportion of the insulating portion, the space efficiency is poor, and the stainless tube is also poor in flexibility. Further, since the space efficiency of each wire is poor, when a plurality of wires are used in a bundle, the wires become thick and the flexibility is significantly reduced, and there is a problem that workability such as terminal processing and connection is poor. .

Therefore, the present invention is suitable for use in a vacuum, has excellent heat resistance and radiation resistance, is highly flexible and compact, has a function of protecting from electrical interference from the outside, and has workability for connection. It is an object of the present invention to provide an easily covered conductor.

[0008]

To achieve the above object, as shown in FIG. 1, a ceramic fiber is cylindrically braided on the outer periphery of an inner conductor 1 to form an insulating coating layer 2, and the outer periphery thereof is formed. An outer conductor 3 is formed by braiding a conductive thin wire into a cylindrical shape.

As the inner conductor 1, a metal wire such as copper wire or aluminum is used. The inner conductor 1 does not necessarily have to be a single wire. Further, the inner conductor 1 is coated with a plating layer of 3 to 50 μm of Ni, Au, Ag, etc. for the purpose of preventing the oxidation of the outer surface, and is densely formed with a ceramic thin film for the purpose of improving the reliability of insulation. You may coat. In this case, if the inner conductor 1 is aluminum, it is also possible to form a thin film layer of aluminum oxide by an electrochemical treatment such as alumite treatment.

In the case of a thermocouple, as shown in FIG. 3, the internal conductors 11 are B, R, S, K, E of JIS standard,
Various thermocouple wires such as J and T can be used. In the case of a thermocouple, the inner conductor 11 does not necessarily have to be one set. Further, the outer surface of the inner conductor 11 may be densely covered with a ceramic thin film for the purpose of preventing oxidation and improving reliability of insulation.

The ceramic fibers forming the insulating coating layers 2 and 12 have a specific resistance of 10 ⁶ Ωcm or more, and are mainly composed of SiO ₂ or Al ₂ O ₃ which are excellent in insulation, heat resistance and radiation resistance. Is used, and the thickness is 0.03 to 2 mm. The reason is that the thickness is 2
This is because if it exceeds 0.3 mm, it is difficult to bend and the flexibility becomes poor, and if it is less than 0.03 mm, the insulating property may be insufficient.

As the conductive thin wire used for braiding the outer conductors 3 and 13, it is possible to use a copper wire plated with Sn, Ni or the like, or a stainless thin wire having a specific resistance of 10 ^-1 Ωcm or less. Insert the thermocouple into the metal tube,
It is also possible to protect each braid from wear and misalignment.

[0013]

The above-mentioned insulating coating layers 2 and 12 are the inner conductors 1 and 1.
1 acts to insulate the outer conductors 3 and 13 from each other, and since it is a braid, it has flexibility. Further, since the outer conductor is also a braid, it has flexibility. The inner conductor 1 and the outer conductor 3 form a pair of electric lines, and supply power or transmit signals.

Further, since the thermocouple according to the present invention does not use an organic material as an insulating material, there is no problem such as gas release or deterioration of insulating characteristics even when used in an environment such as vacuum or radiation. Further, since the outside is covered with the conductive thin wire, there is a shield effect against electric interference from the outside. Needless to say, the flexibility has the same effect as that of the electric wire.

[0015]

Example 1 As shown in FIG. 1, ceramic fibers were braided around the inner conductor 1 to form an insulating coating layer 2 having a thickness of 0.1 mm. At this time, the inner conductor 1 has a wire diameter of 0.
A 5 mm oxygen-free copper wire plated with nickel having a thickness of 10 μm was used. The outer conductor 3 was formed by braiding a thin metal wire having a wire diameter of 0.1 mm on the outer circumference. Table 1 shows three examples.

[0016]

[Table 1]

These electric wires were excellent in flexibility, released little gas in a vacuum, and were excellent in heat resistance and radiation resistance. Further, when this was connected to the control section of the vacuum manipulator using a connector made of ceramics and metal as shown in FIG. 2 and used as a control electric wire, the wiring was compact and Smooth operation is possible without any electrical or physical interference with other devices or wires.

[0018]

[Embodiment 2] As shown in FIG. 3, ceramic fibers are braided on the outer circumference of each of the conductors 11 of the thermocouple to have a thickness of 0.1.
An insulating coating layer 12 having a thickness of mm was formed. At this time, as the conductor 11, a JIS standard K type thermocouple wire having a wire diameter of 0.32 mm was used. The outer conductor 3 was formed by braiding a thin metal wire having a wire diameter of 0.1 mm on the outer periphery of these. Table 2 shows three examples.

[0019]

[Table 2]

These electric wires were excellent in flexibility, emitted little gas in vacuum, and were excellent in heat resistance and radiation resistance. As shown in FIG. 4, it was inserted into a metal tube and used while being protected so as to prevent abrasion and misalignment of the braid. When these thermocouples were used for temperature control, accurate temperature control was possible without any electrical interference from peripheral equipment.

[0021]

As described above, according to the present invention, an insulating coating layer made of a braided ceramic fiber is formed on the outer circumference of an inner conductor, and an outer conductor made of a braided conductive thin wire is formed on the outer circumference of the insulating coating layer. Since it is coated, it has low gas emission and is excellent in heat resistance and radiation resistance. In addition, since it forms a pair with an inner conductor and an outer conductor,
It has good efficiency and is compact. In addition, there is an effect that it is excellent in flexibility and that wiring connection work is easy. In the case of a thermocouple having a pair of internal conductors, in addition to the above-mentioned effects, the shield function of electric interference has a great effect that a reliable signal can be obtained. Further, it goes without saying that it is excellent in flexibility and the wiring connection work is easy.

[Brief description of drawings]

1 is a cross-sectional view showing an embodiment of an insulated conductor, FIG. 2 is a side view of a connector used for connecting to equipment, FIG. 3 is a cross-sectional view of a thermocouple, and FIG. 4 is a cross-section in which the thermocouple is inserted into a metal tube. The figure is shown.

[Explanation of symbols]

 1, 11: Inner conductor 2, 12: Insulation coating 3, 13: Outer conductor 4: Connector-A 5: Connector-B 6: Insulated wire 7: Vacuum flange 14: Metal tube

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshio Murakami, Inventor Yoshio Murakami, No. 801, Mukayama, Naka-cho, Naka-gun, Naka-gun, Ibaraki Japan (72) Inventor, Kazuo Sawada 1-3-3 Shimaya, Konohana-ku, Osaka No. Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Shinji Inazawa 1-3-3 Shimaya, Konohana-ku, Osaka City Sumitomo Electric Industries, Ltd. Osaka Works (72) Inventor Koichi Yamada One Shimaya, Konohana-ku, Osaka City 1 to 3 Sumitomo Electric Industries, Ltd. Osaka Works

Claims (6)

[Claims] 1. A coated conductor in which an insulating coating layer made of a braided ceramic fiber is formed on the outer periphery of an inner conductor, and an outer conductor made of a conductive thin wire is formed on the outer periphery of the insulating coating layer. 2. The specific resistance of the ceramic fiber is 10
The coated conductor according to claim 1, which is ⁶ Ωcm or more. 3. The conductive thin wire has a specific resistance of 10 ⁻¹ Ωc.
The coated conductor according to claim 1, which is m or less. 4. The coated conductor according to claim 1, wherein the surface of the inner conductor is coated with a ceramic thin film having a thickness of 3 to 50 μm. 5. The coated conductor according to claim 1, wherein the plurality of inner conductors having an insulating coating layer formed on the outer periphery are thermocouples. 6. The coated conductor according to claim 1, wherein the coated conductor is further inserted in a metal tube.