JPS581485B2 - Segment connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a segment conductor in which a stranded wire conductor is compression-molded into a fan-shaped cross section.

Generally speaking, when the cross-sectional area of conductors such as rubber or plastic insulated cables reaches approximately 800 mm2, the effective AC resistance increases due to the skin effect, which significantly reduces the allowable current of the cable, so the cable conductor must be divided. As shown in FIG. 1, the structure of the segmented conductor that is used is usually a segmented conductor 1 having a substantially fan-shaped cross section;
This is made up of insulating segment conductors 3 having an approximately fan-shaped cross section provided with an insulating layer 2, which are alternately arranged and twisted together, as shown in FIG.

Conventionally, in order to manufacture the segment conductor, each formed wire is twisted into multiple layers using a wire stranding machine, and each layer is formed into a predetermined shape by upper and lower forming rolls 4 and 5 having a substantially fan-shaped cross section as shown in FIG. A compression molding method is generally known.

In this case, the center angle α of the forming rolls for compression molding each strand is the same angle for each strand, and is usually given as a value obtained by dividing 360 degrees by the number of divisions of the conductor.

However, when the stranded wire conductors of each layer are compression-molded using forming rolls having the same center angle in this way, the forming strands placed in the arc portion 6 of the upper forming roll 4 are well compressed, but the The formed strands disposed in the valleys 7 of the roll 5 are difficult to be compressed, and this tendency is particularly more pronounced in the formed strands disposed at the center of the stranded conductor.

As a result, the gaps between the segment conductors increase, which inevitably causes the cable outer diameter to increase.Also, only the molded wires arranged in the arc portion 6 are strongly compressed, and as a result, these molded wires Since it stretches in the direction, it also has the disadvantage of reducing the actual cross-sectional area as a result.

This invention has been made to eliminate these drawbacks, and is directed to a method for manufacturing a segment conductor, in which each layer of a stranded wire conductor is twisted into multiple layers using a stranding machine, and each layer is compression-molded using a forming roll having a substantially fan-shaped cross section. , the center angle of each of the forming rolls for compression molding the outermost layer of the stranded wire conductor is the value obtained by subtracting 1 to 2 degrees from the value obtained by dividing 360 degrees by the number of divisions of the conductor, and for the compression molding of each other stranded wire conductor. Each strand of the stranded conductor is compression molded at a value that is successively subtracted by 1 to 2 degrees from the center angle of the forming roll that compression molds the outermost layer as you move toward the center of the stranded conductor. It is characterized by

Hereinafter, one embodiment of the present invention will be explained based on the drawings. Fig. 4 shows the manufacturing process of a segment conductor when there are three layers, and 8 is a molding forming the center part of the stranded conductor. It is made of bare wire, such as copper wire or aluminum wire.

Reference numeral 91 denotes a required number of bobbins for supplying copper wire, aluminum wire, etc., which are turned around the central formed wire 8 to form one layer of stranded wire conductor, which is then tightened by the base 101.

Reference numerals 111 and 121 denote upper and lower forming rolls for the first layer, which compression-form the stranded wire conductor into a generally fan-shaped cross section, and are made of steel or the like, the cross section of which is shown in FIG.

Segment conductor 13 with one twisted layer obtained in this way
The required number of forming wires 92 are twisted around the circumferential surface of the wire, tightened with a second layer nozzle 102, and compressed into a substantially fan-shaped cross section using upper and lower forming rolls 112 and 122 for the second layer. .

In a similar manner, the third layer, that is, the outermost formed wire 93 is twisted to produce a segment conductor having three layers.

In this case, the center angle of the lower forming rolls 121, 122, 123, which compression molds the stranded conductor of the third layer, that is, the outermost layer, is 360 degrees divided by the division of the conductor, minus 1 to 2 degrees. The value of compression molding the second layer is the third layer.
The value is set by subtracting 1 to 2 degrees from the central angle α3 for compression molding the layers, and the value for compression molding the first layer is set by subtracting 1 to 2 degrees from the central angle α2 for compression molding the second layer.

That is, the center angle of the lower roll for compression molding each stranded layer has a relationship of α3>α2>α1.

In this way, in this invention, the center angle of the forming roll is reduced by 1 to 2 degrees in the order of the third layer, the second layer, and the first layer. Because the formed wires placed in the arcs and valleys of the conductor can be compressed evenly, the gaps between the conductors seen in conventional segment conductors are reduced, and as a result, the finished outer diameter of the segmented conductors is also reduced. can.

Further, in the present invention, each strand of the stranded wire conductor is compressed uniformly, so that the actual cross-sectional area is not reduced and the effect is great.

In the illustrated embodiment, the case is described in which there are three twisted layers of segment conductors, but there may be no problem if there are two twisted layers or four or more layers.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a segmented conductor, Figure 2 is a cross-sectional view of a divided conductor, Figure 3 is a cross-sectional view of a forming roll, Figure 4 is a diagram of the manufacturing process of a segmented conductor, and Figure 5 is a diagram of this invention. 4, 4', 111, 112, 113... upper forming roll, 5, 5', 121, 122, 123...
...Lower forming roll, 6, 6'...Circular part, 7,
7'...Trough, α...Central angle of conventional forming roll, α1...Central angle of forming roll that compresses the first layer, α2...Compresses the second layer α3: Center angle of the forming roll that compresses the third layer.

Claims (1)

[Claims] 1. In a method for manufacturing a segment conductor in which each layer of a stranded wire conductor that is twisted in multiple layers on a stranding machine is compression-molded using forming rolls with a fan-shaped cross section, the center angle of each forming roll is set to the outermost layer of the stranded wire conductor. What is compression molded is
The value obtained by dividing 360 degrees by the number of divisions of the conductor and subtracting 1 to 2 degrees.For compression molding of each other stranded layer, compress the outermost layer as you move toward the center of the stranded conductor. A method for manufacturing a segment conductor, characterized in that each stranded layer of the stranded wire conductor is compression molded at a value that is sequentially subtracted by 1 to 2 degrees from the center angle of the forming rolls to be formed.