JPS5951682B2 - Manufacturing method of compressed steel core aluminum stranded wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a compressed steel core aluminum stranded wire.

Compression type steel core aluminum stranded wire is a steel core aluminum stranded wire that is made up of steel strands and aluminum strands twisted on top of the steel wires, and is further compression molded using a die etc. to reduce its occupied cross-sectional area. This has the advantage of increasing the cross-sectional area of the conductor to increase current capacity, and reducing the occupied cross-sectional area to reduce the effects of wind pressure and the like.

However, as mentioned above, this type of compression-type steel-core aluminum stranded wire is manufactured by further compression molding ordinary steel-core aluminum stranded wire using a compression die, etc., so the difference in hardness between the steel stranded wire and the aluminum stranded wire is Therefore, as shown in Fig. 1, the aluminum stranded wire 2
A part of the aluminum strands gets into the grooves between the strands of the steel strands 1, and the frictional resistance between the aluminum strands 2 and the steel strands 1 increases.

Therefore, when this type of compressed steel core aluminum stranded wire is used as an overhead wire, its coefficient of linear expansion becomes approximately intermediate between that of steel stranded wire and aluminum stranded wire, which has the drawback of increasing ground movement. It was hot.

The method of the present invention provides a manufacturing method that can easily produce compressed steel core aluminum stranded wires that do not cause such problems.

This will be explained based on an embodiment shown in FIG.

FIG. 2 shows a production line to which the method of the present invention is applied.

In the figure, 1 indicates a steel stranded wire, and 2' indicates an aluminum wire. →It passes through a winder 8 and is wound up as a compressed steel core aluminum stranded wire. However, in the method of the present invention, only the steel stranded wire 1 is compression-molded in advance with a compression die 9 before the twisting machine 6, and the steel A feature is that the groove width between the strands of the stranded wire 1 is made small.

In this embodiment, the compression molding process of the steel stranded wire 1 is incorporated in a series of twisting processes, for example, before the batten 5, but is not limited to this, and can be performed during the manufacturing process of the steel stranded wire 1. There is no problem in incorporating the steel stranded wire 1, as long as the steel stranded wire 1 is compression-molded in advance and the groove width between the strands is made small when manufacturing the compression type steel core aluminum stranded wire.

In addition, the degree of compression molding of the steel stranded wire 1 is such that it is desirable that the groove width between the strands is o, but it is effective if the groove width is smaller than the normal groove width that occurs when the strands are twisted together. occurs.

Furthermore, if a heating step is included in compression molding the stranded steel wire 1, the compression molding operation will be easier to perform.

Incidentally, as the steel stranded wire 1, a known one may be used, but
Depending on the case, an upper made of steel such as Elinvar may be used. A cross-sectional view of the compressed steel core aluminum stranded wire thus obtained is shown in FIG.

As is clear from FIG. 3, according to the method of the present invention, the stranded steel wire 1 is compressed in advance and the groove width between the strands is reduced, so that the final compression molding Even when the aluminum strands 2 are compressed along with the steel strands 1, the amount by which a portion of the aluminum strands 2 enters into the grooves between the strands of the steel strands 1 is reduced.

Therefore, the frictional resistance between the steel strands and the aluminum strands 2 is reduced.

Therefore, when this is used as an overhead wire, when the aluminum strands expand, there is little resistance from the steel strands, so they expand smoothly, and there is a gap between the two, which causes linear expansion between the steel and aluminum. (due to the difference in coefficients), the increase in sag in the span becomes an increase in sag only due to the steel strands, and therefore the increase in sag within the span can be reduced.

Further, since the method of the present invention simply pre-compression molds the steel stranded wire, it can be incorporated into an existing production line, and is therefore extremely simple and workable.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional compressed steel core aluminum stranded wire, Fig. 2 is an explanatory diagram illustrating the method for manufacturing the compressed steel core aluminum stranded wire of the present invention, and Fig. 3 is a cross-sectional view showing a conventional compression type steel core aluminum stranded wire manufactured by the method of the present invention. FIG. 2 is a cross-sectional view showing an example of a compressed steel core aluminum stranded wire. 1... Steel stranded wire, 2... Aluminum stranded wire, 3
, 4... Supply stand, 5... Grain plate, 6... Wire twisting machine, 7... Compression molding die, 8... Winder 1, 9... Compression molding die.

Claims (1)

[Claims] 1. In a method for manufacturing a compression type steel core aluminum stranded wire, in which a steel stranded wire and an aluminum stranded wire twisted thereon are compression molded to reduce the occupied cross-sectional area thereof, the steel stranded wire is A method for manufacturing a compression type steel core aluminum stranded wire, which is characterized by compression molding to reduce the groove width between the strands.