JPS628922B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toroidal coil arranged in a torus shape and forming a toroidal magnetic field in a torus-shaped nuclear fusion device.

Generally, torus-shaped fusion devices are shown in Figures 1 and 2.
As shown in the figure, it is composed of a vacuum vessel 2, a plurality of toroidal coils 1, an air-core alternator coil 3, a poloidal coil 4, and the like. The vacuum vessel 2 has a trapezoidal or circular donut-shaped cross section, and the plasma 5 is confined therein by the magnetic field created by the toroidal coil 1 and the poloidal coil 4. The plasma 5 is heated by generating an induced voltage in the plasma 5 using an air-core alternator 3 wound around the vacuum vessel 2, and by heating the generated current.

As can be seen from FIGS. 1 and 2, this nuclear fusion device has a toroidal coil 1 arranged in a torus shape close to the central axis P-Q in order to increase the aspect ratio. Therefore, the toroidal coil 1 has a trapezoidal shape in a portion 1a close to the central axis P-Q as shown in FIGS. 2 and 3, and a rectangular shape in a portion 1b far from the central axis P-Q.

The trapezoidal part of a conventional toroidal coil was as shown in Figure 3. That is, the toroidal coil 1 is constructed by winding a coil conductor 6 (hereinafter abbreviated as a conductor) around several turns (5 turns in this example). 7 is an interlayer insulation provided to insulate between the conductors 6. A ground insulation 8 is provided on the outer periphery of the toroidal coil 1, and is inserted into a can (not shown) made of non-magnetic steel such as stainless steel. .

By the way, as shown in Fig. 7, the coil 1 is manufactured by bending the conductors 6 one by one using a press or bending roll, joining them by welding etc. at the interlayer crossing part 1c, and laminating 5 turns of the conductor using a jig etc. It is formed into a rectangular cross-sectional shape. Next, as shown in FIG. 8, only the central axis P-Q side portion is machined to taper both the H and U sides. At this time, a temporary insulator or a spacer 9 is used as the interlayer insulation 7, and regular insulation is provided after the above-mentioned machining.

However, as devices have recently become larger and the coil conductor dimensions have become larger, when the conductor 6 is subjected to press or roll bending, the conductor 6 is bent at the bending area l shown in Fig. 7. “Warpage” occurs. The reason for this occurrence will be explained with reference to FIG. When the rectangular cross-sectional conductor shown in a of FIG. 9 is bent at a radius of Ri shown in b, the outer diameter Ro side from the bending center Rn is contracted and the inner Ri side is elongated, resulting in a deformed cross section as shown in FIG. 9b. Further, the coil requires dimensional accuracy in which several layers of conductors 6 are stacked. It is very difficult to accurately bend a conductor with a deformed cross section, and so-called manual reworking is required, resulting in "warpage" S shown in Figure 4 at the end of the conductor. Due to the warp ``S'', an interlayer gap g occurs at the center of the conductor width. Furthermore, when the above-mentioned trapezoidal processing is performed by machining, the "warp" S that occurs at this end is shaved off, so the conductor 6 is shifted in the direction where the interlayer gap g disappears, and the accuracy of the trapezoidal shape is improved. becomes worse. Therefore, it becomes impossible to transmit the strong electromagnetic force generated in the conductors 6 between the conductors 6, and the strength of the coil 1 as a whole also decreases.

This invention was made in order to eliminate the drawbacks of the conventional products as described above. By chamfering the end faces of the conductors in advance, the effect of "warping" caused by bending is reduced, and the conductors The purpose is to ensure that the coils are in close contact with each other and that the coil dimensions can be manufactured with high precision.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 5, the conductor 6 has chamfered portions C at both ends in the width direction. The size of the chamfered portion _C2 is set so that the inner side of the bending radius of the conductor 6 can absorb the deformation and sag S that occur when bending, and the outer side is set so that the sag of the overlapping conductors does not adversely affect the dimensional accuracy during lamination. Make it a Mentri C that can be absorbed.

Even if the conductor 6 subjected to mently C is laminated after being reworked by pressing or roll bending, as shown in Fig. 6, the effect of "warp" S of the conductor is absorbed by the mently, and the distance between the conductors is The influence on the gap g is reduced, and the coil accuracy is greatly improved.

Therefore, even if the coil 1 is machined into a trapezoidal shape, the conductor 6 will not move to reduce the gap g by reducing the "warp" S.

As described above, according to the present invention, by chamfering the ends in the width direction of the coil conductor, the influence of "warpage" due to bending of the conductor is reduced, and a highly accurate toroidal coil can be manufactured, and a strong electromagnetic force can be transferred between each layer. can be conveyed to.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a torus-shaped fusion device, Figure 2
The figure is a plan view of what is shown in Fig. 1, Fig. 3 is a cross-sectional view of a toroidal coil, Fig. 4 is a bending diagram of a conventional coil conductor, Fig. 5 is a view showing the coil conductor of the present invention, and Fig. 6 is a cross-sectional view of a toroidal coil. FIG. 7 is a plan view showing the details of the coil in FIG. 6, FIG. 8 is a sectional view showing the state of the coil taper in FIG. 7, and FIG. FIG. 3 is a diagram for explaining the reason why "warpage" occurs. In the figure, 1 is a toroidal coil, 6 is a coil conductor, and C is a chamfered portion. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A toroidal coil comprising coil conductors integrally connected in a bundle, characterized in that the coil conductors are provided with chamfered portions at widthwise ends thereof. 2. The toroidal coil according to claim 1, wherein the coil conductor integrally connected in a bundle has a trapezoidal end portion on the central axis side. 3. Claim 1, characterized in that the size of the chamfered portion is larger on the inside of the bending radius of the coil conductor and smaller on the outside of the bending radius.
The toroidal coil according to item 1 or 2.