JP3907090B2 - Electromagnetic coil, manufacturing method thereof, and electromagnet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a radiation-resistant electromagnet, and more particularly, to an electromagnetic coil for an electromagnet having a long radiation-resistant life and made of inorganic insulating metal-coated cables (Mineral Insulated Cables).
[0002]
[Prior art]
Conventionally, electromagnets exposed to radiation are often used in particle beam accelerators and related measuring devices. When the electromagnetic coil used for this electromagnet is exposed to radiation, the insulation characteristics and the like deteriorate and it cannot be used. The life of an electromagnet depends on the radiation exposure of the electromagnetic coil, and in particular on the insulator material used there. In electromagnetic coils used in particle beam accelerators, etc., the radiation absorption amount is 10 ⁶ GY (gray) to 10 ⁹ GY. In order to prevent deterioration of the insulation properties of the electromagnetic coil due to the radiation absorption amount, , in the following 10 ⁸ GY using the insulator of the organic material, is 10 ⁸ GY more widely used is that using the insulator inorganic. Among these, in particular, in an electromagnetic coil in which a radiation absorption amount of 10 ⁸ GY or more is expected, it is important that an insulator that insulates between conductors is made of a high-purity inorganic substance.
[0003]
[Problems to be solved by the invention]
Conventionally, ceramics and inorganic cements are used as inorganic materials that are electrically insulating and relatively easily available. When this inorganic insulator material is used as an insulator of an electromagnetic coil, the insulator is coated on the conductor or injected into a gap between adjacent conductors.
[0004]
In this insulation method, the insulator absorbs moisture in the atmosphere, the performance of the insulator deteriorates, and the electrical insulation is reduced. To prevent this, the entire electromagnetic coil must be shielded from the atmosphere by the casing. was there. Therefore, it has a large and complicated structure, requires a complicated manufacturing process, has low reliability of electrical insulation characteristics, and has many problems both technically and economically.
[0005]
The object of the present invention is to eliminate these problems and to withstand a radiation absorption amount of 10 ⁸ GY or more, to be insulated with an inorganic material that is inexpensive and has good workability, and whose structure and manufacture are simple and reliable. It is to provide a high electromagnetic coil and an electromagnet with high radiation absorption characteristics.
[0006]
[Means for Solving the Problems]
The present invention relates to an electromagnetic coil for a radiation-resistant electromagnet formed of an inorganic insulated metal-coated cable, comprising: a conductor made of oxygen-free copper; an outer sheath; and an inorganic insulated metal-coated cable insulated with high-purity magnesium oxide of 95% or more. An electromagnetic coil which is wound and brazed with an insulating hermetic jig at the end of the inorganic insulated metal-coated cable and can be easily deaerated and dried after assembly, and a radiation-resistant electromagnet using the electromagnetic coil.
[0007]
That is, the present invention relates to an inorganic material in which a rod-shaped or hollow metal conductor is hermetically covered with a pipe-shaped metal sheath electrically insulated via an inorganic insulator. In the method for manufacturing an electromagnetic coil for a radiation-resistant electromagnet configured by winding an insulated metal-coated cable, oxygen-free copper is used for an inner conductor and an outer skin of the inorganic-insulated metal-coated cable, and 95% or more of the inorganic insulator is used. An electromagnetic coil is formed of an inorganic insulating metal-coated cable using high-purity magnesium oxide, and the inner conductor and the outer skin are hermetically connected at the terminal end of the electromagnetic coil, and the inner conductor and the outer skin can be electrically insulated. , after assembly, connected to the airtight insulating airtight jig deaerating hole is formed for the vacuum drying of the insulating layer between the inner conductor and the outer skin by brazing method, the insulating airtight jig Deaerated dried to a predetermined electrical resistance than the pores, a method of manufacturing an electromagnetic coil comprising a step of sealing the deaeration holes.
[0009]
Furthermore, the present invention is an electromagnet with a solenoid coil made by the method of manufacturing a conductive magnetic coil.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An electromagnetic coil, a manufacturing method thereof, and an electromagnet using the electromagnetic coil according to the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a front view showing a state in which an insulating hermetic jig is attached to an end portion 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 showing the electromagnetic coil according to the embodiment of the present invention.
[0012]
As shown in FIG. 2, an inorganic insulating 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 a cable sheath 5 is formed into a coil having a predetermined shape. The coil part is fixed with a stainless steel band 8 or the like, and an insulating and airtight jig 2 is attached to the terminal part of the inorganic insulating metal-coated cable 1, and an insulator such as moisture is provided from the cable terminal part to the inside of the cable. Terminate hermetically to prevent gas from deteriorating.
[0013]
As shown in FIG. 1, the insulating hermetic jig 2 includes a central insulating hermetic ring 10 made of a ring made of airtight ceramics such as alumina ceramics, and both ends thereof made of high-purity metal such as oxygen-free copper. The connecting pipe 9 is joined in an airtight manner. The connection pipe 9 is provided with a deaeration hole 6 for terminating the inorganic insulating metal-coated cable and then exhausting the inside of the cable to a vacuum.
[0014]
As shown in FIGS. 1 and 2, a part of the cable sheath 5 at the terminal end of the inorganic insulating metal-coated cable 1 is partially removed to expose the internal conductor 4, and the internal conductor 4 is connected to the insulating airtight jig 2. To penetrate. The cable sheath 5 is airtightly joined to the connection pipe 9 inside the insulating airtight jig 2, and the internal 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 beyond that. Each airtight joining is performed by brazing or the like through an intermediate material or the like as necessary.
[0015]
The assembled electromagnetic coil 7 is fixed to an electromagnet yoke portion (not shown), and then provided to the connection pipe 9 of the insulating hermetic jig 2 to evacuate the inside of the inorganic insulating metal-coated cable 1. After exhausting from the deaeration hole 6, the deaeration hole 6 is sealed, and the electromagnet is completed.
[0016]
【Example】
Hereinafter, the present invention will be described by way of examples.
[0017]
As shown in FIGS. 1 and 2, first, the inorganic insulating metal-coated cables 1 are overlapped and formed into a coil shape. Molding is performed by mechanically applying a force using a winding die or the like so as to have a predetermined linear shape or curved shape.
[0018]
Furthermore, the straight portions of the overlapped cables 1 and the adjacent portions of the curved portions are fixed by brazing, and further overlapped by the stainless steel band 8, and the cables 1 are fastened in a bundle to be fixed. The electromagnetic coil 7 is formed.
[0019]
Next, the insulation hermetic jig 2 is brazed to the end of the cable 1. Thereafter, the inside of the electromagnetic coil 7 is dehumidified through the deaeration hole 6 of the insulating hermetic jig 2, and the insulation resistance of the magnesium oxide insulator as an insulator is secured to 2000 MΩ (DC 1000 V) or more, and the cable 1 is hermetically sealed in this state. The electromagnetic coil 7 is manufactured.
[0020]
The electromagnetic coil 7 performs an insulation resistance test for each process until the electromagnetic coil is incorporated as an electromagnet. In each step, an insulation resistance value of 2000 MΩ (DC 1000 V) or more was obtained. It has been found that the electromagnetic coil of the present invention can be easily assembled and maintained with high characteristics in the assembly of the electromagnetic coil and the electromagnet.
[0021]
Ultimately, it is necessary to evaluate by an energization test. In the energization test, the energization current is 2000 A DC, the incoming water pressure is 13 kg / cm ² , and the outgoing water pressure is 3 kg / cm ^2. In the insulation resistance test after the energization test, 2000 MΩ (DC 100 V) or more was obtained, and it was confirmed that there was no deterioration.
[0022]
In addition, in terms of radiation resistance, as a result of using a high-purity magnesium oxide insulator having a purity of 95%, the radiation absorption amount of about 10 ⁹ GY shows almost no deterioration even after long-term use. A practical and sufficient electromagnet was obtained.
[0023]
【The invention's effect】
As described above, according to the present invention, the radiation-resistant electromagnet and the electromagnetic coil used therefor can be easily molded and assembled while maintaining an insulation resistance value of 2000 MΩ (DC 1000 V) or more, and has excellent radiation resistance characteristics. It was possible to provide an electromagnet coil having high reliability and a long life, and an electromagnet having good radiation resistance using the coil.
[Brief description of the drawings]
FIG. 1 is a front view showing an insulating hermetic jig at an end portion 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 an electromagnetic coil according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 (Inorganic substance insulation metal coating) Cable 2 Insulation airtight jig 3 Electrical terminal 4 Internal conductor 5 Outer skin 6 Deaeration hole 7 Electromagnetic coil 8 Stainless steel band 9 Connection pipe 10 Insulation airtight ring

Claims (2)

Winding an inorganic insulated metal-coated cable that covers a rod-shaped or hollow metallic conductor with a pipe-shaped metal sheath and is electrically insulated through an inorganic insulator. In the manufacturing method of the electromagnetic coil for a radiation-resistant electromagnet configured by rotating, oxygen-free copper is used for the inner conductor and outer skin of the inorganic insulating metal-coated cable, and 95% or more of high-purity magnesium oxide is used for the inorganic insulator. An electromagnetic coil is formed with an inorganic insulating metal-coated cable, and the electromagnetic conductor is hermetically connected to the inner conductor and the outer shell at the end of the electromagnetic coil, and the inner conductor and the outer shell can be electrically insulated. an insulating airtight jig deaerating hole is formed for the vacuum drying of the insulating layer between the body and the outer skin is connected hermetically by brazing method, the insulating airtight jig predetermined from the deaeration holes Deaerated dried to air resistance, the production method of the electromagnetic coil, characterized by comprising the step of sealing the deaeration holes. Electromagnet characterized by using an electromagnetic coil made by the method of claim 1 wherein the conductive magnetic coil.

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