JPS5910569B2 - How to make a circular coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an annular coil, and particularly to a method of manufacturing an annular coil suitable for manufacturing a large-capacity coil in an annular shape.

Generally, when a coil for an electric machine is small, a wire conductor having a small cross section is continuously wound to form a coil.

However, in the case of large-sized coils, due to the manufacturing capacity of the strands that make up the conductor, connections are made every 1/2 circumference or every 1 circumference, and the shape of the strands is pre-wound. It is common to leave it as is. In particular, when the wire of the coil is a hard copper wire or a silver-containing hard copper wire, it is essential to form it into the above-mentioned semicircular shape or circular shape.

For example, FIG. 1 shows an example of a toroidal coil used in a large-scale nuclear fusion experimental device.

The toroidal coil consists of a wire conductor 1, ground insulation 2, inter-conductor insulation 3, and a coil clamping portion 4, and the toroidal coil usually has a wire conductor 1 with a thickness of 10 m or more.
Recommended for several 10m, width 100mm to several 100m,
The dimensions of the coil are 4m in inner diameter and 6m in outer diameter. Moreover, the number of turns of this coil is several tens, and these strands are semicircular conductors, and are one tonne. Currently, as for the possible production capacity, as mentioned above, it is realistic to make semicircular or circular strands of wire, form them into circular arcs, and sequentially connect them to make coils. It's a method. The wire conductor is generally formed by a press method using a mold or by a so-called bending roller method in which the wire is gradually bent through three rollers.

Since a large current flows through the conductor, a hollow water cooling wire is usually attached to cool the conductor. It is most efficient for this hollow wire for water cooling to be attached to the center plane of the conductor, but since toroidal coils are arranged in a torus shape, normally the center side of the torus is on the side of the coil, as shown in Figure 1. Cut. Therefore, a coil pinching portion 4 is formed. Since this cut portion actually experiences the largest temperature rise, generally, as shown in FIG. A groove 5' into which the hollow wire 5 is inserted is provided in the conductor 1 so that the hollow wire 5 is placed in the conductor 1.
For this reason, the coil side surface is not cut in the portion where the coil side surface is not cut, that is, the other portion on the opposite side of the coil pinching portion 4 located on the torus center side.
The groove 5' into which the water-cooled hollow wire 5 is inserted is located at a position before cutting the side surface of the coil, and is not located at the center of the conductor 1. When the conductor 1 is formed into a semicircular or circular shape, folds 6 are likely to occur as shown in FIG. 3 due to the unbalance of the two cross-sectional shapes of the conductor 1. The condition of this fold 6 has a great effect on the connection between the conductors 1. Further, as shown by dotted lines in FIG. 4, undulations 7 are generated in the circumferential direction of the conductor 1 during bending. When manufacturing a coil using the above method, each strand is divided into 1/2 parts as shown in Figure 5.
It is formed into a circular or circular shape and processed so that both ends, that is, the end of the connected conductor 8 and the end of the unconnected conductor 9 as described above, fit perfectly. Particularly in the case of brazing or soldering, the connection surface is 1.5 to 20 times the thickness of the conductor in order to improve the reliability of the connection.
After processing both ends, the winding frame 10 is connected while sequentially connecting the conductors.
However, after the second turn counting from the first conductor, the connected conductor 8 is lifted and expanded in the radial direction within a range close to the elastic limit of the conductor, so that the connection surface with this connected conductor 8 is A working method is used in which the unconnected conductor 9 is deformed within the range of elastic deformation using the wire 11 so that the connecting surfaces of the two are perfectly aligned.

This method requires not only deforming the unconnected conductor 9, but also lifting or contracting the middle part of the conductor as shown in A and B so that the connecting surfaces are pressed together.
In particular, the accuracy of the alignment of the conductor surfaces varies depending on the thickness of the brazing metal to be placed, but when brazing a large area, air is likely to be sucked in and cause brazing defects, so the soldering metal flows out and fills the gap between the conductors. In order to obtain a stable brazing surface, it is necessary to match the thickness to about 30% or less of the thickness of the brazing material, and the surface accuracy is required to be in the range of 0.1 to 0.4 mm. However, the actual conductor has sagging 6 as shown in Figure 3, or undulations 7 in the circumferential direction of the conductor as shown in Figure 4. Therefore, it is necessary to adjust the positional relationship between both conductors. Furthermore, when connecting the connected conductor 8 and the unconnected conductor 9, it is necessary to increase the radius of curvature of the conductor to secure the working space necessary for the connection, but it is necessary to further deform the conductor in this way. Therefore, the environment in which the connection surfaces match becomes worse.

Furthermore, when an actual conductor is viewed in a cross section perpendicular to the circumferential direction, a slight difference in curvature between the upper and lower surfaces causes so-called bending and twisting of the conductor. This difference appears in both the connected conductor 8 and the unconnected conductor 9. Furthermore, since the connection surfaces must be brought together tightly with the conductor floating, it is very difficult to make adjustments by slightly moving or deforming a portion of the arc. The present invention has been made in view of this, and its purpose is to manufacture a toroidal coil that facilitates the work of connecting conductors of a predetermined length and that facilitates the shaping of the connection portion after connection. is to provide.
The present invention is a manufacturing method in which a plurality of conductors of a predetermined length that have been bent to a predetermined curvature are sequentially connected and wound in an annular shape to produce a toroidal coil. The conductor is bent to have a curvature radius of 2. The conductor is bent into a straight line extending in the circumferential connection direction with a radius of curvature of The intended purpose is achieved by winding the conductor. That is, it is not sufficient to simply form the conductor end portion in a straight line, but as shown in FIG. As shown in FIG. 11, even if the straight portions 13a and 13b protrude outside the circumference of the conductor 1 which has been bent to a predetermined curvature, there is no big difference in terms of work, especially in preparation for the connection work, but after the connection Since the winding operation is difficult, a lot of time is required for forming, and the curvature may be inaccurate. In other words, when winding the conductor 1, it is necessary to form the vicinity of the connection part in the same circumferential shape as the other forming parts. In this case, the straight portion 13
Most advantageously, a, b extend in the direction of the circumferential connection of the radius of curvature of the conductor bent to a predetermined curvature. The present invention will be described below based on embodiments shown in the drawings.

FIG. 6 shows the shape of a wire conductor 12 according to an embodiment of the present invention. At both ends of the wire conductor 12, a circumferential connection of the radius of curvature of the wire conductor 12, which is bent to a predetermined curvature, is provided. A straight portion 13 extending in the direction is formed. The method for manufacturing such a wire conductor 12 is to create a mold in which the straight portions 13 at both ends extend in the circumferential connecting direction of the radius of curvature of the conductor, or to form using bending rollers as described above.
After bending the entire body, it is molded using a mold in which the straight portions 13 at both ends extend in the circumferential connection direction of the radius of curvature of the conductor. Next, the conductors 12 formed in this way are connected. Similar to the conventional method, this embodiment also requires a heating space for connection;
As shown in FIG. 7, with the connected conductor 12a spread out,
The connected conductor straight portion 13a and the connected conductor straight portion 13b of the unconnected conductor 12b have a structure in which the conductor processed surfaces of the straight portion and the straight portion match. Furthermore, as shown in FIG. 8, by aligning the connecting ends in a straight line shape, the setup work for aligning the surfaces to be connected is greatly simplified. That is, there is an advantage that the alignment work can be completed simply by maintaining the linearity of the connected conductor 12a and the unconnected conductor 12b. The longer the length of the straight portion 13 of the conductor 12 shown in FIG. 6, the smaller the dimension that increases the radius of curvature of the conductor when making a connection. Fig. 7 shows the state of the winding when the inner diameter is 4 m, but in this case, the straight portions 13a, b are
By providing m, the conductor lifting dimension can be reduced to about 60% of the conventional method, that is, the amount of deformation for increasing the radius of curvature of the conductors 12a, b can be reduced to about 60% of the conventional method.

This makes it possible to further reduce working time and plastic deformation of the conductor. In addition, it is very advantageous in terms of safety because the stretching force for the conductor can be reduced.
The length of the straight portion 13 is such that it is sufficiently softened during connection, that is,
It must have dimensions that allow it to be annealed. That is, as shown in FIG. 9, it is necessary to wind it into the same shape as the curvature of the normal portion other than the straight portions 13a and 13b. In actual work,
Since the conductor is sufficiently blunted by the connecting operation such as brazing the linear dimension, it is easy to form the connected portion along the circumference after connection. According to the method for manufacturing a toroidal coil of the present invention described above, only the ends of a conductor of a predetermined length that have been bent to a predetermined curvature are connected circumferentially to the conductor with a radius of curvature that has been bent to a predetermined curvature. Constructed in a straight line extending in the direction,
After the straight parts of the ends of the conductor are joined together, the connected part is deformed to a specified curvature and the conductor is wound in a circular shape, so the connected end of the conductor is connected to the straight part. This simplifies the process of aligning the conductors to be connected, which simplifies the process of aligning the straight parts. Since the connection part extends in the circumferential connection direction of the conductor's radius of curvature, it is easy to shape the connection part along the circumference after connection.
This method is very effective when used in the production of circular coils.

[Brief explanation of drawings]

Figure 1 is a plan view showing a cross section of a part of a toroidal coil used in a nuclear fusion device, Figure 2 is a side view of the cross section, Figure 3 is an explanatory diagram showing how the conductor collapses, and Figure 4 is FIG. 5 is a plan view showing a conventional connection preparation state; FIG. 6 is a side view showing the shape of an embodiment of the wire conductor used in the present invention; FIG. 8 is a perspective view of the connection portion, FIG. 9 is a side view showing the shape of the conductor after winding, FIG. 10, and FIG. The figure is a side view showing the shape of the end of the conductor. 8, 12a... Connected conductor, 9, 12b...
...Unconnected conductor, 12... Element wire conductor, 13.
...Straight section, 13a, 13b...Connection conductor connection section.

Claims (1)

[Claims] 1 In a manufacturing method in which a plurality of conductors of a predetermined length that have been bent to a predetermined curvature are sequentially connected and wound in an annular shape to produce a toroidal coil, only the ends of the conductors of the predetermined length are bent to a predetermined length. A conductor bent to a curvature is formed into a straight line extending in the circumferential connection direction with a radius of curvature, and after joining the straight parts of the ends of the conductor, the connecting part is deformed to a specified curvature to form a conductor. 1. A method for manufacturing a circular coil, characterized in that the coil is wound around the coil.