JPH04370671A - Conductor connecting structure - Google Patents

Abstract

PURPOSE:To provide a connecting structure of a hollow conductor, which has a narrow softening range and with which operations are possible even though the operating space is small. CONSTITUTION:A passage for a coolant is formed in a hollow conductor 21, and at its end a notch (processing groove) 26 is provided in such a way as including the passage. After welding of the end part excluding the notch, a connecting piece (blocking piece) 22 is installed so as to cover the notch and is welded to the hollow conductor 21. This lessens the softening range compared with connection by the brazing as conventional, and conductor can be connected easily even where the operation space is restricted.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a conductor connection structure suitable for connecting hollow conductors each having a groove (flow path) formed therein for passing a cooling medium, and particularly for use in a nuclear fusion device. This invention relates to a connection structure for conductors of a poloidal coil.

0002

[Prior Art] Conventional connection between conductors is described in Patent No. 544.
As shown in No. 587, the area of the connection part is made larger than the plate thickness, and the connection is performed by brazing, welding, etc.

0003

[Problem to be Solved by the Invention] An outline of a nuclear fusion device is shown in FIGS. 4 and 5. As shown in the figure, plasma 2 is held in a vacuum container 1 whose interior is evacuated. A plurality of toroidal magnetic field coils 3 are arranged on the outer periphery of the vacuum vessel 1 at predetermined intervals in the circumferential direction of the torus.
It generates a toroidal magnetic field, which can be said to be the core of. Further, a poloidal magnetic field coil 4 is arranged between the toroidal magnetic field coil 3 and the vacuum vessel 1, concentrically with the vessel 1, and controls the generation of plasma current. Reference numeral 5 denotes a thick wall portion forming the vacuum container 1, 6 a bellows portion arranged alternately with the thick wall portion 5, 7 a current transformer, 8 a vacuum evacuation device, 9
is a bellows.

As mentioned above, since the toroidal magnetic field coil 3 and the poloidal magnetic field coil 4 are interlinked, as shown in FIG.
0, the toroidal magnetic field coil 3 is assembled from this assembly/disassembly section 10, and then the assembly/disassembly section 10 is metallurgically connected to assemble the entire device.

By the way, the poloidal magnetic field coil 4 is shown in FIG.
As shown in FIG. 2, the coil is normally supported in the vertical direction by a coil support 11, and has a sliding structure in the radial direction to release thermal expansion of the coil. Further, a padding 13 is placed between the coil support 11 and the coil 4 on both sides of the coil outlet 12 to form a fixing point of the coil 4 in the horizontal direction.

[0006] In the poloidal magnetic field coil 4 constructed as described above, connection strength becomes a problem when metallurgically connecting the assembly and disassembly parts 10. The poloidal magnetic field coil is a high-strength direct water-cooled coil that uses a hollow conductor of hard copper, but the 0.2% yield strength of the normal part is about 30 kg/mm2. Normally, hollow conductor connections are connected by brazing, and if you try to connect assembled and disassembled parts using the brazing method, the length of the connection part needs to be about 300 mm, and the 0.2% proof strength of the connection part of the brazed part It becomes about 3 to 4 kg/mm2, which is a significant decrease. In addition, there was a problem that a large work space was required, making on-site work difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a conductor connection structure that has a small softening range and can be operated even in a narrow working space.

[0008]

[Means for Solving the Problems] The above object is achieved by connecting hollow conductors to each other by combination welding.

[0009]

[Function] If welding is used to connect hollow conductors, the local heating area can be smaller than in brazing, so the softening range of the conductors is reduced and a connection with higher strength can be obtained. Furthermore, since the space for connection work is smaller in welding work, it becomes easier to perform connection work in limited spaces, such as on-site work or modification work after equipment assembly.

0010

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 1, a hollow conductor 21 having grooves for passing a cooling medium is used as the poloidal magnetic field coil conductor. If the hollow conductors are directly welded together, the welding groove at the connection part will be closed. Therefore, a machined groove 26 is provided at the end of the conductor, and the hollow conductors are butted together to close the weld groove 26.
A groove 27 is provided on the other contact surface and TIG is performed as shown in Fig. 3.
Weld. At this time, the conductor around the connection part is cooled with water to keep the extent of softening caused by welding as small as possible.

Next, a hole closing piece 22 for closing this processed groove 26 is attached to the groove, and along the gap between the groove and the piece,
When TIG welding is performed and sealed, a welded structure as shown in FIG. 2 is obtained.

[0013]

[Effects of the Invention] When hard copper is welded and connected, the strength of the welded part is about 8 kg/mm2, which is more than twice the strength of the joint made by brazing. Also, the softening range due to welding is about 100 mm, which is about 1/1 compared to brazing.
It becomes 3.

Therefore, according to the present invention, the softening range in the vicinity of the connection portion is small, making it possible to weld a poloidal magnetic field coil suitable for on-site work with limited work space and repair work after device assembly.

[Brief explanation of drawings]

FIG. 1 is an external view of each part before welding work according to an embodiment of the present invention.

FIG. 2 is an external view after completion of welding work according to an embodiment of the present invention.

FIG. 3 is an outline diagram after TIG welding and before electron beam welding according to an embodiment of the present invention.

FIG. 4 is a conceptual diagram of a nuclear fusion device.

FIG. 5 is a sectional view taken along line AA in FIG. 4;

FIG. 6 is a plan view of the poloidal magnetic field coil of the fusion device before assembly.

[Explanation of symbols]

21... Hollow conductor, 22... Hole closing piece, 23... Welding part,
26... Machining groove, 27... Bevel.

Claims (3)

[Claims] 1. A connection structure between hollow conductors each having a flow path formed therein for passing a cooling medium, characterized in that the ends of the hollow conductors are connected by welding. connection structure. 2. The conductor connection structure according to claim 1, wherein a notch portion is formed at an end of the hollow conductor to include the flow path, and an end portion other than the notch portion is welded. A conductor connection structure characterized by having a connection piece that is later provided so as to cover the notch, is welded to the hollow conductor, and forms a flow path together with the hollow conductor. 3. The conductor connection structure according to claim 2, wherein an end portion of the hollow conductor excluding the notch portion is provided with a groove.