JPS6312355B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a compression method for connecting conductors of electric wires or cables using compression sleeves. For example, in order to form a conductor connection part having an outer diameter approximately equal to the outer diameter of the conductor by sequentially compressing a circular sleeve placed over the conductor connection part using a hexagonal die, a round die, a hexagonal die, and a round die, as shown in FIG. The compression method shown in A or B is adopted. The method shown in Figure A starts compression from the center of the sleeve 2, and then sequentially moves toward both ends of the sleeve 2 while overlapping by about 1/3 of the pressing width W of the compression die 3. The method shown in Fig. 3 is to compress the sleeve 2 by first aligning the end of the sleeve 2 with the pressing width end of the die 3 (,), and then sequentially moving toward the center of the sleeve 2 while overlapping them in the same way as above. Then, the data is compressed in the following order. 1,1 is a conductor. However, with either method, when the sleeve is compressed, the conductor inside the sleeve is also compressed, but the expansion of the sleeve and conductor due to compression is usually maximum at the outer circumference and decreases as it goes inward, so there is an imbalance. When the conductor is a concentric stranded wire, as shown in Fig. 2, the outer strands swell up and the portion of the conductor 1 that is close to the sleeve 2 becomes enormous. Accidents that tear the insulating paper are likely to occur. The present invention has been made in order to eliminate the above-mentioned drawbacks, and it is an object of the present invention to provide a method for compressing a conductor connection portion in which the conductor adjacent to the sleeve does not bulge after compression. The present invention is a method for connecting conductors by compressing a sleeve in multiple stages, and when performing compression in the final stage or in the final stage and the stage before it, approximately 1/2 of the pressing width of the compression die is first applied at both ends. This is a method of compressing a conductor joint, which is characterized by compressing the conductor by overlapping the conductor. The conductor to be compressed and connected according to the present invention is a stranded conductor of an electric wire or cable, and the initial cross-sectional shape of the sleeve may be circular, oval, polygonal (e.g., hexagonal), etc., and the number of times of multistage compression is The cross-sectional shape of the compression part used in the compression method used each time in two or more times may be round, polygonal (eg, hexagonal), or elliptical. Hereinafter, the present invention will be explained by examples using the drawings. FIG. 3 is a longitudinal sectional view illustrating an embodiment of the method of the present invention. Conductors 1, 1 to be connected in the diagram
A sleeve 2 is placed over the outer periphery of the abutted conductor 2 and compressed in multiple stages by a compression die 3, so that the outer diameter of the sleeve 2 becomes approximately equal to the outer diameter of the conductor 1. The method shown in FIG. 3 is used to perform this final stage compression, or the final stage compression and the previous stage compression. Indicates the compression order of ~. That is,
In the first compression of both ends, about 1/2 of the pressing width W of the die 3 is overlapped on the conductor 1 and compressed. This compresses both ends of the sleeve 2 as well as the portion of the conductor 1 adjacent to the sleeve. Next, the end of the sleeve 2 and the pressing width end of the die 3 are made substantially coincident and compressed (,). After that, as usual, compress it toward the center while overlapping by about 1/3 of the pressing width W of the die (...
…). Although only compression is shown in the figure, it may be compressed at two or more locations. EXAMPLE Conductors of an oil-filled (OF) power cable having a conductor cross-sectional area of 1×800 mm ² were connected by multi-stage compression using the method of the present invention and the conventional method shown in FIGS. 1A and 1B. However, in the method of the present invention, only the final stage and the previous stage were compressed by the method shown in FIG. 3, and the two stages before that were both compressed by the method shown in FIG. 1B. Figure 4 is a diagram showing the final conductor connection, and the results of investigating the bulge e of the conductor 1 shown in the figure (the figure shows half of one side), the torn area _l1 of the insulating paper 4, and the number of torn sheets are shown in Table 4. As shown in 1.

[Table] From Table 1, it was found that the connection made by the method of the present invention had no bulging of the conductor or tearing of the insulating paper. On the other hand, these occurrences are large in the case of the conventional method, and the degree of occurrence is particularly large in the case of the A diagram method. As described above, in the multi-stage compression connection method, when compressing the final stage or the final stage and the stage before it, the method of the present invention initially applies approximately 1/2 of the pressing width of the soybean for compression at both ends. Since the conductor is compressed by overlapping the conductor, the sleeve and the part of the conductor close to the sleeve are also compressed, so the conductor is not too bulky or the insulating paper is torn as seen in the conventional example. This has the effect of providing a conductor connection. In addition, in the method of the present invention, after the first two ends are connected, the sleeve is compressed from both ends toward the center, so that the conductor stretches toward the center and does not extend to the portions of the conductor that are close to the sleeves on both sides. It has the effect of preventing overgrowth.

[Brief explanation of the drawing]

FIGS. 1A and 1B are longitudinal cross-sectional views illustrating examples of conventional compression methods, respectively. FIG. 2 is a longitudinal cross-sectional view showing an example of a large portion of a conductor according to a conventional method. FIG. 3 is a longitudinal sectional view illustrating an embodiment of the method of the present invention. FIG. 4 is a longitudinal cross-sectional view showing the investigated locations of the conductor connection portion in the example. 1... Conductor, 2... Sleeve, 3... Compression die, 4... Insulating paper, ~... Compression order.

Claims (1)

[Claims] 1. In a method for connecting conductors by compressing a sleeve in multiple stages, when compression is applied in the final stage or in the final stage and the stage before it, at both ends, approximately 1 of the pressing width of the compression die is applied. A method of compressing a conductor connection portion, which is characterized by compressing a conductor by overlapping /2 on the conductor. 2 After first compressing both ends, compress the sleeve end so that it almost coincides with the pressing width end of the compression die, and then compress it toward the center while overlapping by about 1/3 of the die pressing width as usual. A method for compressing a conductor connection portion according to claim 1.