JPS6022804B2 - toroidal coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toroidal coil in a torus-shaped nuclear fusion device, in which a plurality of coil conductors are arranged in a torus shape and are divided into upper and lower parts and are fastened together at a saddle joint.

Generally, a torus-shaped fusion device, as shown in FIGS. 1 and 2, includes a vacuum vessel 2, a plurality of toroidal coils 1,
It is composed of an air-core current transformer coil (poloidal coil) 3 and the like. The vacuum vessel 2 has a trapezoidal or circular donut-shaped cross section, and the plasma 4 is confined therein by magnetic fields in the toroidal direction, poloidal direction, and perpendicular direction. Heating of the plasma 4 is performed by generating an induced voltage in the plasma 4 by an air current transformer coil 3 wound near the vacuum vessel 2, and by using a current generated by the induced voltage. As can be seen from FIGS. 1 and 2, this nuclear fusion device is roughly constructed by intersecting a toroidal coil 1, a vacuum vessel 2, and an air-core current transformer coil 3.

5A and 5B are joint parts of the toroidal coil 1 divided into upper and lower parts.

Therefore, when manufacturing the device, as shown in Figure 1,
Either the multiple toroidal coils 1 must be divided into two, or the vacuum vessel 2 and the air-core current transformer coil 3 must be divided into two in the torus direction (circumferential direction). Cannot be assembled.

The conventional toroidal coil and the toroidal coil of the present invention also have a structure in which the former toroidal coil is divided into two parts.

As shown in FIG. 3, the joint between the two halves of a conventional toroidal coil is a frictional joint using a bolt tightening force.

In the figure, a toroidal coil 1 is wound with a coil conductor 6 several turns.

11 is interlayer insulation.

At the junction 5A of the conductors 6a and 6b, which are divided into two in the vertical direction in the longitudinal direction, both conductors 6a and 6b are collectively tightened using vertical bolts 7 and nuts 8 to form an integrated toroidal coil 1. are doing. 6c is a through hole in the thickness direction of the conductors 6a and 6b in the joint 5A. 9 is an insulating washer and a high-power tube with a single feed. Note that the vertical mounting bolt 7 is installed on the joint 5B side as well as on the joint 5A side. , are vertically connected by an insulating tube 10, an insulating washer 9, and a nut 8. However,
With the recent progress in nuclear fusion research, the current in the toroidal coil 1 has increased and the electromagnetic force acting on this coil has also become stronger.

To this end, the toroidal coil is usually supported by being surrounded by an outer frame (not shown). Further, the toroidal coil 1 thermally expands due to Joule heat, but since it is restrained by the outer frame, a large compressive force is accumulated inside, and this force overcomes the frictional force of the joints 5A and 5B. Then, the toroidal coil 1 slides at the joints 5A and 5B. This slippage occurs repeatedly in response to fluctuations in the value of the current flowing through the toroidal coil. Due to the repeated operation of the fusion device over a long period of time, the upper and lower coils, which are divided into two and connected together, become phosphorous on the contact surface 12 of the joint.
You will be restrained and will not be able to slide. Therefore, a large compressive force is repeatedly applied to the toroidal coil 1, leading to fatigue failure of the conductor 6. Furthermore, as shown in FIG. 4, another example of the conventional joint between the two halves of a toroidal coil is one that uses frictional force due to vertical bolt attachment and pin joint. In the figure, pin holes 6d are formed in the thickness direction of the conductors 6a and 6b of the joint portion 5A, and a plurality of pins 13 are driven into the conductors 6a and 6b to couple both conductors. A gap is provided between each pin 13 and an insulator 14 is inserted to prevent short circuit between each layer. In this way, the frictional force caused by the cotton bonding at the joint and the shear strength of the pin 13 make it possible to withstand the electromagnetic force and the compressive force caused by thermal expansion of the conductors 6a and 6b. In the structure of the joint of these conventional toroidal coils, expansion and contraction of the conductors 6a and 6b due to electromagnetic force and heat occurs centering around the bolt 7 or pin 13 of the joint, causing phosphorization on the dividing surface 12. It was extremely difficult to prevent this.

This invention provides an expansion/contraction absorber near the joint of the vertically divided coil conductor, and absorbs the expansion/contraction of the conductor due to electromagnetic force and thermal influence, thereby reducing the influence on the joint and causing slippage. The purpose is to reduce the size of the joint surface and prevent moths from attaching to the joint surface.

FIG. 5 is a diagram according to an embodiment of the present invention. 6 is a front view of FIG. 5, and numerals 7 to 14 are the same as those of the conventional device. The conductor 21 of the toroidal coil 20 includes upper and lower conductors 21a and 21
b is divided in the longitudinal direction, and has 0 joint parts 5A, 5B (
The insulating tube 10 is fitted into the through hole 21c (shown in FIG. 1), and is vertically attached using vertical bolts 7 and nuts 8.

Further, a pin 13 is driven into the penetrating pin hole 21d to connect both conductors 21a and 21b. Conductor 21
A, 21b are provided with constricted portions 22 having a small cross-sectional area close to the joint portions.

The cross section of this constriction shows that the strength of the conductor 21 at the joint is
It is formed to have a strength equal to or slightly lower than that of a and 21b, and becomes zero as it approaches the tightening bolt 7 and pin 13. An interlayer insulating filling 23 is inserted into the gap between the constricted portion 22 so that the conductors 21a and 21b are brought into close contact with each other. In this way, by providing the constricted portion 22 near the joint of the conductors 21a, 21b with a reduced cross-sectional area so that the strength is equal to or lower than the strength of the conductor at the joint, the conductors 21a, 21b are
Even if 1b is subjected to tensile force due to electromagnetic force or compressive force due to thermal expansion, extensional strain or compressive strain is generated in this constricted portion 22, and the elongation or contraction of the joint portion can be reduced. To prevent galling or seizure of the conductor at the joint surface 12.

Note that the constricted portions 22 are provided at the joint portion 5A on one side and the joint portion 6A on the other side.

Further, in the above embodiment, the constricted portion 22 is formed by the upper and lower conductors 21a,
Although it is provided at one location near the tethering portion of 21b, it may be provided at multiple locations if permitted from the viewpoint of strength and manufacturing cost.

Furthermore, the constriction part 22 was provided in the above embodiment as an expansion/contraction absorption part provided on the conductor, but instead of the constriction part, the conductor between this part was cut and a flexible stranded wire or thin conductive plate was laminated. may be connected between conductors by welding or the like to absorb expansion and contraction.

As described above, according to the present invention, expansion and contraction absorbing sections are provided near the joints of the upper and lower conductors of the two-part toroidal coil, and the expansion and contraction caused by the electromagnetic force and thermal effects of the conductor are absorbed by the deflection of the expansion and contraction absorption sections. Since the conductor is absorbed by stretching and elongation, galling or seizure of the conductor at the bonding surface is prevented, current conduction is reliably maintained, and disassembly can be carried out without any trouble.

[Brief explanation of the drawings] Fig. 1 shows a conventional model. A vertical sectional view of the main parts of a toroidal fusion device equipped with a toroidal coil, FIG. 2 is a plan view of the device shown in FIG. 1, and FIG. 3 is an enlarged sectional view of the joint of the conductor of the toroidal coil shown in FIG. ,
FIG. 4 is an enlarged cross-sectional view of a conductor joint showing another example of a slave, FIG. 5 is an enlarged cross-sectional view of a conductor joint of a toroidal coil according to an embodiment of the present invention, and FIG. FIG. 6 is a front view of the joint portion of the conductor shown in FIG. 5; 5A, 58... Joint part, 7... Bolt, 20... Toroidal coil, 21... Conductor, 21a...
Upper conductor, 21b...Lower conductor, 22...
Neck part that forms the elastic absorption part. Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 1 Figure 2 Figure 6 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. In a toroidal coil in which a wound coil conductor is divided into two in the longitudinal direction and both conductors are pressed and connected at a joint, both conductors are connected at a position close to the joint. In addition, an expansion/contraction absorption part with a smaller cross-sectional area and greater expansion/contraction is provided on the middle side of the conductor, and the expansion/contraction from both conductors is absorbed by each expansion/contraction absorption part, thereby preventing the effect on the joint part. Features a toroidal coil. 2. The toroidal coil according to claim 1, wherein the expansion/contraction absorbing portion is formed by a constricted portion having a reduced cross-sectional area of the conductor. 3. The toroidal coil according to claim 1, wherein the stretchable absorbing portion is formed by connecting flexible conductors in series.