JPS59230190A - Magnetic field generating coil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a magnetic field generating coil, and particularly to a magnetic field generating coil suitable for generating a magnetic field for plasma confinement in a nuclear fusion device.

[Background of the invention]

Magnetic field generating coils used in nuclear fusion devices, etc. are composed of coils formed by a winding method called oven winding, in which a conductor is spirally wound. A pair of lead wires are provided for supplying current. FIGS. 1 and 2 show an example of such a magnetic field generating coil.

In FIG. 1, a coil 10 is formed by an open winding method in which a conductor 12 is spirally wound with a transition portion 14. The outer winding start portion of this coil 10 is bent to form a lead wire portion 16. As shown in FIG. 2, an L-shaped lead wire portion 20 is fixed to the inner winding end portion 18 by brazing or the like.

In the coil 10 configured as described above, when a current I is passed in the direction shown by the arrow 22, a magnetic field B is generated in the direction shown by the arrow 24. Furthermore, when a current flows through the coil 1o, a magnetic field BA also occurs in the lead wire portion 16.20 as shown by an arrow 24.26.
, F3m occurs.

A magnetic field BA is generated in this lead wire portion 16.20.

BB acts as an irregular magnetic field with respect to the magnetic field B shown by the arrow 24 generated in the coil 1o, which is not preferable.

This irregular magnetic field δB has a current and an area of the current loop S.
Then, it is expressed as δ13o: IXS. Therefore, in the coil 10 shown in FIG. 1, the lead wire portions 16 and 20 are not on the same plane, but the cross-sectional shapes of the lead wire portions 16 and 20 are in the same direction. Damage, lead wire part 16.2
The spacing between zeros becomes wider.

Therefore, when the area of the current loop is large, a large irregular magnetic field δB is generated.

As nuclear fusion devices have become larger in recent years, and the magnetic field that stabilizes plasma confinement and plasma confinement has become increasingly high, the irregular magnetic field of the coil itself or the lead wire has become a problem. Lead wire portion 16 of the coil 10 shown in Figure 1
．． The irregular magnetic field generated at 20 has a large negative effect on the plasma confinement or the plasma confinement stabilizing magnetic field, which is highly undesirable for the fusion device.

[Purpose of the invention]

The present invention has been made in order to eliminate the drawbacks of the prior art, and an object of the present invention is to provide a magnetic field generating coil that can reduce the generation of irregular magnetic fields in the lead wire portion of the coil.

[Summary of the invention]

In the present invention, the inner conductor part and the outer conductor part of a conductor that is spirally wound to form a coil are crossed in the middle of the coil winding, and the inner conductor part including the winding end part of the coil is connected to the outer conductor part. It is constructed to achieve the above purpose by arranging a pair of lead wires placed on the outside and placed at the winding start and end of the coil in parallel with each other facing each other. be.

[Embodiments of the invention]

Preferred embodiments of the magnetic field generating coil according to the present invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals are given to the parts corresponding to the parts explained in the prior art, and the explanation thereof will be omitted.

FIG. 3 is a perspective view of an embodiment of the magnetic field generating coil according to the present invention. In FIG. 3, the coil 10 has a winding start portion bent to form a lead wire portion 16, and a first spring 28 and a second spring 30 intersect at a crossing portion 32, The second spring 30 is arranged outside the first spring 28. The terminal end of the second spring 30 is bent at the end of the winding of the coil 10 to form a lead wire section 34.

As shown in FIG. 4, the crossing section 32 has a notch hole 36 formed in the first spring 28, and a notch 38 of the second spring 30 is fitted into this notch hole 36.

The formation of this crossing section 32 can be done, for example, by cutting the second spring 30 at the joining line 42 and cutting the end on the first roll side into the first spring 28.
The second spring 30 can be formed by joining the second spring 30 at the joining line 42 by brazing or the like after processing it so that it can be fitted into the notch hole 36 formed in the above. Incidentally, the reduction in current flow path area due to the formation of such notch holes 36 and notches 38 can be eliminated by increasing the thickness of the first spring 28 and the second spring 30, etc. can do.

In the coil 10 configured as described above, the lead wire portion 16 and the lead wire portion 34 are arranged in parallel and facing each other on the same plane as the coil 10, and the lead wire portion 1
6. Since the cross-sectional shapes of 34 are in the same direction, the lead wire portions 16° 34 are made sufficiently close to each other to reduce the area of the current loop and greatly reduce the irregular magnetic field in the lead wire portions compared to the conventional method. be able to.

FIG. 5 is a perspective view showing another embodiment of the notch forming the transition portion 32. In the embodiment shown in FIG.
Groove-shaped notches 44, 46 are formed in each of the first spring 28 and the second spring 30, and the transition portion 32 is formed by fitting these notches 44, 46 into each other. be able to.

In the above example, the coil 10 was formed by winding the conductor twice, but the coil 10 was formed by winding the conductor three times.
Even when the coil 10 is formed by winding the coil 10 more than once, it is possible to similarly form crossing wire portions and arrange the lead wire portions 16 and 34 in the same manner as in the previous embodiment. Further, in the above embodiments, the conductor has a rectangular cross section, but the conductor may have another shape.

〔Effect of the invention〕

As explained above, according to the present invention, the irregular magnetic field in the Riet wire portion of the coil can be greatly reduced.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a conventional magnetic field generating coil, Fig. 2 is a side view of the magnetic field generating coil shown in Fig. 1, and Fig. 3 is a perspective view of an embodiment of the magnetic field generating coil according to the present invention. FIG. 4 is a perspective view showing details of the crossing section of the embodiment, and FIG. 5 is a perspective view of an embodiment of a notch forming the crossing section of the magnetic field generating coil according to the present invention. . 10... Coil, 14.32... Transfer part, 16,2
0゜34... Lead wire part, 28... First spring, 30
...Second spring, 36...Notch hole, 38,44.4
6... Notch part. Agent: Patent Attorney Tatsuyuki Unuma) Condolences

Claims (1)

[Claims] 1. A magnetic field generating coil consisting of a coil formed by spirally winding a conductor and a pair of lead wires for supplying current provided at both ends of the conductor of this coil. An inner conductor that is wound and located inside the coil and an outer conductor that is located outside the coil are crossed in the middle of the coil winding, and the inner conductor including the end portion of the conductor winding of the coil is placed outside the outer conductor. Further, a magnetic field generating coil characterized in that the pair of lead wires are arranged in parallel and facing each other. 2. The intersection of the inner conductor and the outer conductor is achieved by providing a notch in the middle of both, and fitting the notch so that the inner conductor is located outside the outer conductor at the intersection. Claim 1 characterized in that it is formed in a multilayered manner.
The magnetic field generating coil described in Section 1.