JPH03108289A - Connecting method for steel core aluminum twisted wire - Google Patents

Abstract

PURPOSE:To form a watertight state at end sections of a connecting sleeve without damaging a covering layer by compressing and connecting aluminum twisted wires with the connecting sleeve with the inner diameter D satisfying a specific condition. CONSTITUTION:When steel core aluminum twisted wires (ACSR) 10 are compressed and connected by indent compression with a connecting sleeve 1 having the inner diameter D satisfying the condition of the equation, the tensile strength of a connection section is increased, and a watertight state is formed at end sections of the connecting sleeve 1 with a short length without damaging a covering layer. Even when a waterproof protective layer deteriorates, the infiltration of rain water into the sleeve 1 is prevented, and the occurrence of corrosion progress is suppressed. In the equation, (d) is the outer diameter of an ACSR aluminum twisted wire layer 11.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention is directed to a steel core aluminum stranded wire (hereinafter referred to as ACS) which is formed by forming a layer of aluminum strands, which serve as a conductive member, on the outer periphery of a steel core, which serves as a tension member. The present invention relates to a method of connecting AC3R for overhead power distribution lines, in particular to a method of connecting AC3R for overhead power distribution lines.

[Prior Art] In addition to the large-sized AC3R used for ultra-high voltage overhead power transmission lines, AC3R has an aluminum stranded wire layer 11 twisted around the outer periphery of a steel core 12 as shown in FIG. A small-sized AC8RIO coated with an insulating coating layer 13 is also used for overhead distribution lines. Normally, this type of AC3R has an insulating coating layer 13, but this coating waste 13 is omitted and the bare wire is used. Sometimes used in states. A like this
When connecting C3RIO, a connecting sleeve 1 as shown in FIG. 1 has conventionally been used.

That is, it has a partition wall 2 in the center, and stranded wire insertion holes 3 are formed on both sides of the partition wall 2.

When connecting the AC8RIO as described above with the connection sleeve 1, the AC8RIO as shown in FIG.
The coating layer 13 is peeled off in stages to expose the aluminum stranded wire layer 11, and the tip of the aluminum stranded wire layer 11.11 that has been peeled off and exposed is inserted into the insertion hole 3.3 as shown in FIG. Insert the BIB until it hits the partition wall 2, and in that state insert the BIB with an oval cross section.
It has been common practice to sequentially compress the material using a two-split die having holes, and to cover the connection sleeve 1 with the waterproof protective layer 7 that continues from the insulating coating layer 13 to the connection sleeve 1 after the compression is completed.

In this case, the tensile strength of the compressed part must of course be able to withstand the tension of the AC3RIO overhead wire when it is connected to a steel tower, etc.
It was necessary to configure the length of the connecting sleeve to be long so as to withstand the tensile load due to such a large overhead wire tension.

However, when the connecting sleeve becomes longer, various problems arise as follows.

(1) To perform sufficient compression, the number of compressions increases (12
301i1 on both sides for 0nm2 AC3R connection
(compression of about 1 J is performed), and the connection work takes a lot of effort.

(2) As the number of times of compression increases, the linear sleeve extends more.

(3) The connection sleeve is likely to bend.

(4) Many irregularities are formed on the surface of the connection sleeve due to compression, and these irregularities may damage the waterproof protective layer 7 or shorten its lifespan.

(5) Tapered parts are sometimes formed at both ends of the connecting sleeve to prevent large fluctuations in compressive load from occurring at the boundary between the aluminum stranded wire layers at the ends of the connecting sleeve. As a result, the entire connecting sleeve becomes longer, which may exacerbate the above-mentioned problems.

(6) If the waterproof protective layer deteriorates, there is a risk that mountain water may enter from the end of the sleeve and accelerate corrosion of the connection portion.

[Problems to be Solved by the Invention] In order to solve the above-mentioned problems, it is necessary to shorten the length of the connection sleeve 1 and maintain sufficient strength to withstand the tension of the AC3RIO overhead wire. In addition, the waterproof protective layer 7 is constructed to prevent rainwater from easily entering the connection sleeve even if the waterproof protection layer 7 is damaged by unevenness caused during die compression or becomes old, and the connection is It is necessary to prevent deterioration due to corrosion of the parts.

As one of the measures to solve the problems caused by the die compression described above, the applicant previously proposed a connection method using indent compression as shown in FIG.

This is done by inserting compression pins 6.6 with circular tips alternately into the aluminum stranded wire layer 11 while the outer periphery of the connecting sleeve 1 is firmly restrained by two split clamps. A volume change in the gap between the layers or the gap between the aluminum stranded wire layer and the connecting sleeve is caused, and the compression pin 6
．． 6 is inserted, the volume inside the connection sleeve is increased,
By generating sufficient internal pressure within the insertion hole 3, a pressure bonding force due to R1 friction between the aluminum stranded wire layer and the connection sleeve is generated.

However, even in this case, if the gap existing between the aluminum stranded wire FiiJ11 and the connection sleeve 1 is large, the connection sleeve must be lengthened or the pin inserted in order to obtain a strong enough deflection to withstand the above-mentioned overhead wire tension. It becomes necessary to increase the number, and the above-mentioned problems cannot necessarily be solved.

The purpose of the present invention is to solve the problems of the prior art as described above, to shorten the length of the connecting sleeve, and to maintain sufficient strength to withstand AC3R overhead line tension, or to provide a waterproof protective layer. The purpose of the present invention is to provide a new AC3R connection method that is free from the risk of easy intrusion of mountain water even if damage or deterioration occurs to the AC3R.

[Means for Solving the Problems] In the present invention, when AC3R is compressed and connected using a connecting sleeve, when the outer diameter of the aluminum stranded wire layer is d and the inner diameter of the connecting sleeve is D, I) / d≦1 .2. In addition, when AC8R having an insulating coating layer is compressed and connected using a connecting sleeve, a small diameter stranded aluminum wire I4 with an exposed step is inserted into the connecting sleeve. A two-stage insertion hole having an insertion hole and a large-diameter insertion hole into which the end of the insulating liquid NP- is inserted is formed, and tapered portions are formed at both ends of the outer 11 of the connection sleeve, and the two-stage insertion hole The aluminum stranded wire layer and the coating layer are inserted into the respective insertion holes of the sleeve for compression connection, and in this case, the insertion end of the large-diameter insertion hole is located earlier than the start of the 4ill re-tapered part of the sleeve. The method is to arrange the data so that it exists in the center, or to use an indent compression method for each compression.

By setting D/d≦1.2 as the configuration condition, it is possible to secure a sufficient tensile load of the connection part after compression connection, and even if the connection sleeve is shortened, there is no risk of loss of reliability. disappears.

In addition, if the insulating coating layer is inserted into the end of the connection sleeve so that it can be compressed, and a tapered surface is formed on the outer periphery and then compressed, a watertight state can be created at the end of the connection sleeve without damaging the coating layer. Therefore, even if the waterproof protective layer deteriorates, rainwater is prevented from entering the sleeve, and corrosion progress can be prevented.

[Example] The present invention will be described below with reference to Examples.

Figure 4 shows the inner diameter of the insertion hole 3 of the connection sleeve 1 shown in Figure 1 when a 120m+2 electric wire is used as AC3R, the inner surface of the sleeve is filled with a compound containing SIc, and the compound is indented and compressed, and Figure 2 shows the inner diameter of the insertion hole 3 of the connection sleeve 1 shown in Figure 1. Aluminum stranded wire layer 1 shown in
1 is a diagram plotting the relationship between the ratio D/d to the outer diameter d of 1 and the tensile load.

In addition, the tensile test in this case is a universal tensile test lX1! A tensile test was conducted using an AC3R machine at a tensile speed of 10 speeds/minute per meter of length, and the breaking load in that case is shown.

As can be seen from FIG. 4, when D/d becomes larger than 1.2, the tensile load rapidly decreases, making it difficult to shorten the connecting sleeve. Therefore, to ensure sufficient tensile load and thereby reduce the length of the connecting sleeve, D/
It turns out that it is very suitable to configure d to be smaller than 1.2.

Note that the minimum value of D/d is necessarily 1, but strictly 1
It is appropriate to consider tolerances during manufacturing and allow for a certain degree of culm.

-h shows an experiment using indented compression as the compression method, but the tendency shown in Figure 4 is the same in die compression, and even in the case of die compression connection, D, / It has been confirmed through experiments that by making d smaller than 1.2, a sufficient tensile load can be secured and the connecting sleeve can also be shortened.

After completion of compression, the above-described waterproof protective layer 7 may be covered with a self-adhesive tape, a tape with an adhesive layer, a heat-shrinkable tube, a solvent + Vt wet type tube, a mechanically expanded diameter type tube, or the like.

However, as explained earlier, the above-mentioned waterproof protective layer sometimes becomes unable to maintain sufficient waterproof performance over time due to damage caused by paris that tends to occur when the sleeve is compressed, or due to aging of the waterproof protective layer itself. It is possible. In such a case, there is a strong possibility that rainwater will enter the connection sleeve and accelerate corrosion, accelerating the deterioration of the connection portion.

What is shown in FIG. 5 is a cross-sectional view of an embodiment of the connection sleeve used in the present invention, which can still maintain sufficient waterproof effect even if such a problem occurs in the waterproof protective layer. .

The connection sleeve 1 shown in this embodiment has a small-diameter stranded wire insertion hole 3 into which the stranded wire is inserted and a large-diameter coating layer insertion hole 4 into which the end of the stripped insulation coating layer is inserted, and both ends of the sleeve A tapered portion 5 is formed on the outside of the portion.

FIG. 6 shows an AC cable having an insulating coating layer 13 using the connection sleeve 1 according to the present invention having the configuration shown in FIG.
It is an explanatory sectional view showing the case where 8RIO is compressed and connected.

As shown in FIG. 2, the aluminum stranded wire layer is stripped in steps to expose it, and the aluminum stranded wire layer 11 is inserted into the stranded wire insertion hole 3, which is a small diameter insertion hole in FIG. is inserted into the coating layer insertion hole 4, which is a large-diameter insertion hole, and the compression pins 6 and 6 are inserted alternately into the aluminum stranded wire layer 11 as shown in the figure, thereby indenting and compressing and connecting the wires. .

When the single layer of twisted aluminum is compressed in the twisted wire insertion hole 3 as described above, the compressive force also extends to the coating layer insertion hole 4, and the compressive force against the insulation coating layer 13 is applied to the coating layer insertion hole. will be added. In order to increase the generation of compressive force in such a covering layer insertion hole, it is desirable to insert the compression pin 6 for indent compression as close as possible to the insulation wave & layer 13.

In addition, in order to ensure the generation of compressive force to the insulating coating layer, the position of the insertion end 4a of the coating layer insertion hole shown in FIG. It is best to form it so that

With the above configuration, the aluminum stranded wire layer maintains sufficient strength through compression, and the compression force due to the connection sleeve is also generated on the outer periphery of the insulation coating layer, so that the waterproof protective layer 7 may be damaged in the unlikely event that it occurs. Alternatively, even if the waterproof performance becomes insufficient due to deterioration due to aging, it will be possible to sufficiently prevent rainwater from entering the inside of the sleeve connection, thereby greatly extending the life of the connection. Become.

Note that although the above example shows the case where compression is performed by indent compression, there is no problem with die compression. There is no risk of force being applied, and there is no risk of damage to the insulation coating FgJ13 due to compression.

An advantage of adopting indent compression in the present invention is that the AC3R steel core 12 is deformed into a snake shape by inserting the compression pin 6, which increases the tensile holding force and allows the sleeve to be made more compact. In addition, the outer diameter of the connection sleeve does not deform as in the case of die compression, and there is almost no formation of flakes, making it easier to attach the waterproof protective layer and eliminating the risk of poor finishing. There are also advantages.

Furthermore, since the insulating coating layer is inserted and held at the end of the connection sleeve, this part will act as a cushion when vibration occurs in the AC3R, and this will prevent vibrations from occurring at the end of the connection sleeve. It can also be expected to have the advantage of preventing wire breakage due to fatigue.

[Effects of the Invention] As described above, by using the AC3R connection method according to the present invention, the tensile load of the connection sleeve can be greatly increased, and the connection sleeve can be shortened by that much, which is different from the conventional method. Not only can the various problems that have been observed be resolved, but by inserting and retaining a portion of the insulating coating layer into the connection sleeve, it is possible to fully demonstrate the waterproof effect and also retain the effect of preventing fatigue rupture. This makes it possible to greatly improve the life of the connection part.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an example of the connection sleeve, Fig. 2 is a sketch showing the state where the insulation coating layer of AC3R is removed,
Fig. 3 is a cross-sectional view showing a state in which the connecting sleeve is compressed and connected by indent compression, Fig. 4 is a diagram showing the relationship between the ratio of the inner diameter of the connecting sleeve to the outer diameter d of the aluminum stranded wire layer and tensile load, FIG. 5 is a cross-sectional view showing another embodiment of a connecting sleeve used in the present invention, FIG. 6 is a cross-sectional view showing a state in which the connecting sleeve shown in FIG. 5 is connected by the connecting method according to the present invention, Figure 7 is a sectional view showing the conventional connection situation;
The figure is a sectional view showing a specific example of AC3R for overhead power distribution. 1: Connection sleeve, 3: Twisted wire insertion hole, 4: Covering layer insertion hole, 4a: Insertion end, 5: Tapered part, 5a: Taper start part, 6: Compression pin, 7: Waterproof cA protection layer, 10: AC3R5 11 Ni-aluminum twisted wire layer, 12: Steel core, 13: Covering layer. Figure 3

Claims (4)

[Claims] (1) When a steel core aluminum stranded wire made by twisting aluminum wires around the outer periphery of a steel core to form an aluminum stranded wire layer is compressed and connected using a connecting sleeve, the outer diameter of the aluminum stranded wire layer is d, and the connecting sleeve A method for connecting steel-core aluminum stranded wires in such a manner that D/d≦1.2, where D is the inner diameter of the wire. (2) When connecting steel-core aluminum stranded wires, which are made by twisting aluminum wires around the outer periphery of a steel core to form an aluminum stranded wire layer and covering the layer with an insulating coating layer, using a connection sleeve, the connection sleeve A two-stage insertion hole is formed, which has a small-diameter insertion hole into which the stripped aluminum stranded wire layer is inserted and a large-diameter insertion hole into which the end of the insulation coating layer is inserted. A tapered part is formed in the above-mentioned 2.
A method of connecting steel-core aluminum stranded wires by inserting an aluminum stranded wire layer and a coating layer into each insertion hole of a stage insertion hole and connecting them by compression. (3) The method for connecting steel-core aluminum stranded wires according to claim 2, wherein the insertion end of the large-diameter insertion hole is located closer to the center of the sleeve than the start of the tapered portion. (4) The connection of the steel-core aluminum stranded wire according to any one of claims 1 to 3, wherein the compression method is indented compression in which pins are inserted alternately into the aluminum stranded wire layer while restraining the outside of the connection sleeve. Method.