JPH11233340A - Electromagnetic coil, manufacture thereof and electromagnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the manufacture of an electromagnetic coil and to enhance the reliability of the electrical insulation characteristic of the coil by a method, wherein the electromagnetic coil is formed of a specified inorganic matter-insulated metal- coated cable, the coil is hermetically connected with an internal conductor and a skin at the terminal part of this electromagnetic coil and after the coil is assembled, an insulating hermetic jig is hermetically connected with the coil. SOLUTION: One part of a skin 5 of an inorganic matter-insulated metal-coated cable 1 at the terminal part of the inorganic matter-insulated metal-coated cable 1 insulated with a high purity of at least 95% of magnesium oxide is removed to make an internal conductor 4 expose, and this internal conductor 4 is made to penetrate an insulating hermetic jig 2. The skin 5 is hermetically bonded to a connection pipe 9 on the inside of the jig 2 and the conductor 4 is hermetically bonded to a connection pipe 9 on the opposite side to the pipe 9 on the inside of the jig 2. The respective bondings are performed by soldering. After an electromagnetic coil completed an assembly has been fixed on a yoke part of an electromagnet, evacuation is conducted through a vent 6 provided in the pipe 9 of the jig 2 and after that, the vent 6 is sealed to form the electromagnet using the electomagnetic coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-resistant electromagnet, and more particularly to an inorganic insulated metal-coated cable.
The present invention relates to an electromagnetic coil for an electromagnet made of insulated cables having a long radiation-proof life and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, electromagnets exposed to radiation are widely used in particle beam accelerators and related measuring devices. When the electromagnetic coil used for this electromagnet is exposed to radiation, its insulating properties and the like deteriorate, and it becomes impossible to use it.
The life of an electromagnet depends on the radiation exposure of the electromagnetic coil, and in particular on the insulator material used therein.
In electromagnetic coils used in particle beam accelerators and the like, the radiation absorption is used in the range of 10 ⁶ GY (gray) to 10 ⁹ GY. In the case of 10 ⁸ GY or less, an organic insulator is used, and in the case of 10 ⁸ GY or more, an inorganic insulator is used. Among them, it is particularly important for an electromagnetic coil that is expected to have a radiation absorption of 10 ⁸ GY or more that the insulator that insulates between conductors be composed of a high-purity inorganic substance.

[0003]

Heretofore, ceramics and inorganic cement have been used as inorganic substances which are electrically insulating and relatively easily available. When this inorganic insulator material is used as an insulator for an electromagnetic coil, the insulator is coated on the conductor or injected into the gap between adjacent conductors.

In this insulating method, the insulator absorbs moisture in the atmosphere, and the performance of the insulator is deteriorated, and the electrical insulation is reduced. To prevent this, the entire electromagnetic coil is sealed with the atmosphere by a casing. I needed to shut it off. Therefore, it has a large and complicated structure, and requires a complicated manufacturing process.
The reliability of the electrical insulation properties was low, and there were many technical and economic problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive and easily processable inorganic material which can withstand a radiation absorption of 10 ⁸ GY or more, and which has a simple structure and a simple structure. An object of the present invention is to provide a highly reliable electromagnetic coil and an electromagnet having high radiation absorption resistance.

[0006]

According to the present invention, there is provided an electromagnetic coil for a radiation-resistant electromagnet formed of an inorganic insulated metal-coated cable, comprising: a conductor made of oxygen-free copper;
% Of an inorganic insulated metal-coated cable insulated with high-purity magnesium oxide of at least 100%, and an insulating airtight jig is brazed to the end of the inorganic insulated metal-coated cable. And a radiation-resistant electromagnet using the same.

That is, according to the present invention, an inner conductor made of a rod-shaped or hollow metal conductor is hermetically sealed in a state where the inner conductor is made of a pipe-shaped metal and is electrically insulated via an inorganic insulator. In an electromagnetic coil for radiation-resistant electromagnets formed by winding an inorganic insulated metal-coated cable covered with oxygen-free copper as an inner conductor and an outer sheath of the inorganic insulated metal-coated cable, the inorganic insulator is made of 95% or more. An electromagnetic coil is formed with an inorganic insulated metal-coated cable using high-purity magnesium oxide.At the end of this electromagnetic coil, the inner conductor is airtightly connected to the outer conductor and the inner conductor is electrically insulated from the outer conductor. An electromagnetic coil in which an insulating airtight jig provided with a deaeration hole for vacuum drying the insulator layer between the inner conductor and the outer cover after assembly is airtightly connected.

Further, the present invention provides a method of manufacturing the above-mentioned electromagnetic coil, wherein the above-mentioned inorganic insulated metal-coated cable is used to form a winding on the electromagnetic coil, and an insulating airtight jig is brazed to the end of the electromagnetic coil. This is a method for manufacturing an electromagnetic coil, which comprises a step of performing airtight connection, performing degassing and drying until a predetermined electric resistance is obtained from a degassing hole of an insulating airtight jig, and sealing the same.

Further, the present invention is an electromagnet using either the above-mentioned electromagnetic coil or an electromagnetic coil manufactured by the method for manufacturing an electromagnetic coil.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electromagnetic coil, a method for manufacturing the same, and an electromagnet using the same according to the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a state in which an insulating airtight jig is attached to a terminal portion of an inorganic insulating metal-coated cable of an electromagnetic coil according to an embodiment of the present invention. FIG.
1 is an external perspective view showing an electromagnetic coil according to an embodiment of the present invention.

As shown in FIG. 2, an inorganic insulated metal-coated cable 1 in which an insulator made of high-purity magnesium oxide is packed between an inner conductor 4 made of oxygen-free copper and an outer sheath 5 of the cable is used. The coil portion is fixed with a stainless steel band 8 or the like, and an insulating airtight jig 2 is attached to the end portion of the inorganic insulated metal-coated cable 1. Airtightly so that gas which degrades the insulator does not enter.

As shown in FIG. 1, the insulating hermetic jig 2 has a central insulating hermetic ring 10 formed of an airtight ceramics ring such as alumina ceramics, and has high-end portions such as oxygen-free copper at both ends. A connection pipe 9 made of a pure metal is hermetically joined. The connection pipe 9 is provided with a deaeration hole 6 for evacuating the inside of the cable after terminating the inorganic insulating metal-coated cable.

As shown in FIGS. 1 and 2, a part of the outer sheath 5 of the cable at the end of the inorganic insulated metal-coated cable 1 is removed to expose the inner conductor 4, and the inner conductor 4 is insulated and airtight. The jig 2 is penetrated. The outer sheath 5 of the cable is airtightly joined to the connection pipe 9 inside the insulating airtight jig 2, and the inner conductor 4 is airtightly joined to the connection pipe 9 on the opposite side. The electrode terminal 3 is connected to the internal conductor 4 ahead. Each hermetic joining is performed by brazing or the like via an intermediate material or the like as necessary.

After the assembled electromagnetic coil 7 is fixed to a yoke portion of an electromagnet (not shown), it is connected to a connection pipe 9 of an insulating airtight jig 2 to evacuate the inside of the inorganic insulated metal-coated cable 1. After evacuating from the provided deaeration hole 6, the deaeration hole 6 is sealed, and the electromagnet is completed.

[0016]

EXAMPLES The present invention will be described below with reference to examples.

As shown in FIGS. 1 and 2, first, an inorganic insulated metal-coated cable 1 is overlapped and formed into a coil shape. Forming is performed by mechanically applying a force using a winding mold or the like so as to have a predetermined linear shape or curved shape.

Further, the adjacent portions of the straight portion and the curved portion of the superposed cable 1 are fixed by brazing, and further superposed by a stainless steel band 8 to form the cable 1.
Are fixed in a bundle to form the electromagnetic coil 7.

Next, an insulating airtight jig 2 is attached to the end of the cable 1.
Brazing. Then, the deaeration hole 6 of the insulating airtight jig 2
To dehumidify the inside of the electromagnetic coil 7 and reduce the insulation resistance of the magnesium oxide insulator, which is an insulator, to 2000 MΩ (D
C1000 V) or more, and in this state, the cable 1 is hermetically sealed to manufacture the electromagnetic coil 7.

The electromagnetic coil 7 performs an insulation resistance test for each process until the electromagnetic coil is incorporated as an electromagnet.
In each process, the insulation resistance value is 2000 MΩ (DC1000
V) was obtained. It has been found that in the electromagnetic coil of the present invention, in assembling the electromagnetic coil and assembling the electromagnet, it is easy to assemble and can be manufactured while maintaining high characteristics.

Finally, it is necessary to evaluate by an energization test. The energization test is performed at a current of 2000 A DC, an inlet pressure of 13 kg / cm ² , and an outlet pressure of 3 kg / cm ^2. The cooling effect is also good, and in the insulation resistance test after the conduction test, 2000 MΩ (DC 100
V) or more was obtained, and it was confirmed that there was no deterioration.

As for the radiation resistance characteristics, the use of a high-purity magnesium oxide insulator having a purity of 95% results in almost no deterioration of the characteristics even when used for a long time at a radiation absorption amount of about 10 ⁹ GY. A practically sufficient electromagnet was obtained without being seen.

[0023]

As described above, according to the present invention, it is possible to easily form and assemble a radiation-resistant electromagnet and an electromagnetic coil used therein while maintaining an insulation resistance value of 2000 MΩ (1000 V DC) or more. An electromagnet coil having excellent radiation resistance, high reliability, and long life, and an electromagnet using the same and having good radiation resistance were provided.

[Brief description of the drawings]

FIG. 1 is a front view showing an insulating airtight jig at the terminal end of an inorganic insulating metal-coated cable of an electromagnetic coil according to an embodiment of the present invention.

FIG. 2 is an external perspective view of the electromagnetic coil according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 (Inorganic insulating metal coating) cable 2 Insulated airtight jig 3 Electric terminal 4 Inner conductor 5 Outer skin 6 Deaeration hole 7 Electromagnetic coil 8 Stainless steel band 9 Connection pipe 10 Insulated airtight ring

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshiyuki Saito 6-7-1, Koriyama, Taishiro-ku, Sendai-shi, Miyagi-ken Tokin Co., Ltd.

Claims (3)

[Claims] 1. An inorganic insulating material that hermetically covers an inner conductor made of a rod-shaped or hollow metal conductor in a state of being electrically insulated with an outer sheath made of a pipe-shaped metal via an inorganic insulator. In an electromagnetic coil for a radiation-resistant electromagnet formed by winding a metal-coated cable, oxygen-free copper is used for an inner conductor and an outer sheath of the inorganic-insulated metal-coated cable, and a high-purity magnesium oxide of 95% or more is used for the inorganic insulator. An electromagnetic coil is formed with an inorganic insulated metal-coated cable using, and at the end of the electromagnetic coil, the inner conductor and the outer cover are air-tightly connected, and the inner conductor and the outer cover can be electrically insulated. An electromagnetic coil, wherein an insulating airtight jig having a deaerated hole for vacuum drying an insulator layer between an inner conductor and an outer skin is connected in an airtight state. 2. The method of manufacturing an electromagnetic coil according to claim 1, wherein the cable is wound around an electromagnetic coil using the inorganic insulated metal-coated cable according to claim 1, and an insulating airtight jig is attached to the end of the electromagnetic coil. A method for manufacturing an electromagnetic coil, comprising: air-tightly connecting by an attaching method, performing deaeration drying until a predetermined electric resistance is obtained from a deaeration hole of an insulating airtight jig, and sealing the same. 3. An electromagnet using any one of the electromagnetic coil according to claim 1 and an electromagnetic coil manufactured by the method for manufacturing an electromagnetic coil according to claim 2.