JP2586150B2 - How to compress the clamp for transmission line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a case in which a compression type termination clamp for a transmission line is crimped to an end of a wire by a reverse compression method, and an abnormality is caused in an aluminum stranded wire layer inside the termination clamp. The present invention relates to a novel compression method for a transmission line anchoring clamp which confirms and detects whether or not elongation has occurred, thereby appropriately avoiding the possibility of an accident.

[Prior Art] As shown in FIG. 5, a transmission line has a steel core aluminum stranded wire (hereinafter referred to as ACSR) in which an aluminum stranded wire layer 11 serving as a conductive member is twisted around an outer periphery of a steel core 12 serving as a tension member. 10) is used.

In order to hold this to the steel tower, it is usual to crimp a compression type holding clamp as shown in FIG. 5 to the end of the ACSR 10 and hold it.

That is, 1 is an aluminum clamp for crimping the aluminum stranded wire layer, 2 is a jumper terminal for connecting a jumper wire, and 3 is a steel core 12 in which the aluminum stranded wire layer 11 is stepped and exposed as shown in the figure. Reference numeral 4 denotes a steel clamp to be crimped, 4 denotes a stay metal fitting to be fixed to the tower-side metal fitting, 5 denotes a tapered portion, and 13 denotes a binding wire that binds the ends of the steel core 12 so as not to be loose.

At the time of this crimping, the end of the ACSR 10 was stripped off as shown in the figure, the aluminum clamp 1 was temporarily attached, and the steel core 12 was removed.
First, press the steel clamp 3 on the aluminum clamp 1
And the aluminum clamp 1 and the steel clamp 3 are combined, and as shown in FIG. ₂ , the gap G2 between the jumper terminal and the retainer is brought sufficiently close to each other, so that the steel clamp 3
The tapered portion 5 of the aluminum clamp 1 and the tapered surface of the aluminum clamp 1 corresponding to the tapered portion 5 are brought into close contact with each other so that rainwater does not enter from the end of the retaining clamp.

For this purpose, conventionally, first, the steel clamp 3 and the aluminum clamp 1 are completely brought into close contact with each other, and in this state, the aluminum clamp 1 is sequentially moved from the side of the retaining bracket 4 toward the tip of the ACSR 10 as shown by a sixth middle arrow. The normal compression method for compression has been adopted for a long time. However, in the case of the normal compression method, as the aluminum clamp 1 is sequentially compressed toward its tip, the internal aluminum stranded wire layer 11 is also compressed together to cause compression elongation. Bird cage-shaped laughter BC is formed on the aluminum stranded wire layer 11 by gathering at the tip of the wire. This laughter BC is apt to catch moisture and dust, which may cause corrosion to progress, resulting in early disconnection or the like.

For this reason, a reverse compression method has been developed in which, instead of forward compression, which compresses toward the distal end, as shown in FIG.
In many cases, this compression method has been adopted for compressing the ACSR retention clamp. According to this reverse compression method, the aluminum clamp 1 and the ACSR 10 are fixed first, and then the aluminum clamp 1 and the ACSR 10 are successively compressed toward the fasteners as shown in FIG. The risk of laughter caused by putting out is eliminated.

[Problems to be Solved by the Invention] In the reverse compression method, as described above, the tip of the aluminum clamp 1 is first compression-fixed to the electric wire, and then the aluminum clamp 1 is sequentially compressed toward the retaining fitting 4 side. This compression not only causes the aluminum clamp 1 to undergo compression elongation, but also causes the internal aluminum stranded wire layer 11 to undergo compression elongation. Therefore, when the decompression of the above may be set gap G ₁ between the end face and the end face of the anchor bracket 4 jumper terminal 2 of the aluminum clamp 1 as shown in FIG. 1, the decompressor Conversely aluminum clamp 1 second jumper terminal 2 and the anchor bracket 4 as shown in FIG is set so that the gap G ₂ capable of forming a snugly close contact when the aluminum clamp 1 has occurred compressed elongation by Compress.

However, at this time, not only the aluminum clamp 1 causes compression elongation, but also the internal aluminum stranded wire layer 11 also undergoes compression elongation along with the compression elongation of the aluminum lamp 1, so that in this reverse compression method, As shown in FIG. 1, a predetermined distance δ ₁ is set between the steel clamp 3 and the end of the aluminum stranded wire layer 11 in consideration of the compression and elongation of the aluminum stranded wire layer 11, just appropriate intervals when compressed elongation occurs in the aluminum stranded wire layer 11 as shown in FIG. 2 after completion [delta] ₂
Then, inverse compression is performed by setting.

This interval δ ₂ must be an interval allowed by design. For example, if the amount of compression of the die compression when compressing the aluminum clamp 1 is excessive, the aluminum stranded wire layer 11 may exceed the designed compression elongation. resulting elongation, this distance [delta] ₂ in some cases becomes smaller than the design value.

Simply there is no problem if only because the interval [delta] ₂ is smaller, the interval of [delta] ₂ is too small is to aluminum stranded wire layer 11 is too resulting compressed elongation, such excessive compression The elongation also causes the inner steel core 12 to elongate, and there is a possibility that the elongation becomes excessive and an internal disconnection occurs.

If a break occurs in the steel core 12 that should become a tension member in this way, the holding force of the ACSR 10 due to the holding clamp is significantly reduced, and the ACSR 10 cannot withstand the overhead wire tension of the ACSR 10 and the ACSR 10 cannot be pulled from the holding clamp. There is a high possibility that it will lead to serious accidents such as falling off.

However, such an excessive compression and elongation of the aluminum stranded wire layer 11 and the accompanying internal disconnection of the steel core 12 cannot be confirmed from the outside at all, and the actual situation is that they rely solely on the skill and intuition of the workers. However, it is extremely dangerous if the anchoring operation is performed without noticing the abnormal compression.

An object of the present invention is to measure the distance δ ₂ between the end of the steel clamp 3 and the compressed end of the aluminum stranded wire layer 11 shown in FIG. Accordingly, it is an object of the present invention to provide a new compression method of the transmission line anchoring clamp which can prevent the occurrence of the unexpected accident as described above.

[Means for Solving the Problems] The present invention relates to a step of an aluminum stranded wire layer in which a stripped steel core is exposed and protruded in order to connect a retaining clamp when a compression-type retaining clamp is compressed by a reverse compression method. A magnetic material such as a magnetic steel body or a magnetic powder is installed at the stripped end, and when the compression of the retaining clamp is completed, the end of the aluminum stranded wire layer specified by the magnetic material and the end of the steel clamp are separated. A method of compressing a retaining clamp is to detect an interval between the two by a magnetic sensor and to measure whether the interval has an appropriate interval.

[Operation] If a magnetic sensor detects the distance between the end of the steel clamp and the end of the aluminum stranded wire layer, the distance between the two terminals, which cannot be visually confirmed, can be accurately measured. Since it is possible to check whether or not the proper spacing is maintained, it is possible to detect abnormalities in the compression and elongation of the aluminum stranded wire layer in advance, and to check in advance for the occurrence of unexpected situations such as breakage of the steel core. It becomes possible.

Examples Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is an explanatory view showing a state before compression when compressing a retaining clamp at an end of an ACSR by a method according to the present invention.

As already described, the jumper terminal 2 and the stay 4
Gap calculated between the end faces of the aluminum clamp
G ₁ is set, and a space δ ₁ is set between the end face of the steel clamp 3 and the end face of the aluminum stranded wire layer 11 to calculate the compression and elongation of the aluminum stranded wire layer 11 when the aluminum clamp 1 is compressed. Is done.

Thus, in the present invention, a magnetic substance 20 such as a magnetic steel body or a magnetic powder is provided at the end of the aluminum stranded wire layer. The magnetic substance 20 may be any substance as long as it can be detected by a magnetic sensor described later, and is not limited to the above specific examples.

FIG. 2 is an explanatory diagram showing a state in which the initially set retention clamp is reversely compressed as shown in FIG.

Gap G ₂ next by a gap G ₁ of FIG. 1 is compressed elongation of the aluminum clamp 1 by compression, aluminum clamp 1
And the tapered surface of the steel clamp 3 are in close contact with each other,
Intrusion of rainwater or the like is thereby sufficiently prevented. On the other hand, the initial interval [delta] ₁ aluminum twisted layer 11 will result in compression extends along with the compressed elongation of the aluminum clamp 1 becomes narrow as intervals [delta] ₂ shown in Figure 2.

FIG. 3 shows a steel clamp 3 in a dashed line circle in FIG.
FIG. 4 is an explanatory view showing a state in which an aluminum clamp 1 on an outer periphery is removed in order to show an end face state of each of the aluminum stranded wire layers 11.

Even if the aluminum stranded wire layer 11 undergoes compression elongation, the interval δ
_{As long as 2} is kept at the design interval and undergoes compression and elongation, the steel core inside the aluminum stranded wire layer 11 will not be broken. However, if the interval δ ₂ is smaller than the designed interval, it indicates that the aluminum stranded wire layer 11 has undergone abnormal elongation. There is a possibility that disconnection has occurred.

Figure 4 is such gap [delta] ₂ is an explanatory view showing a state in which measured from the outside of the aluminum clamp 1, 21 magnetic sensors, 22 is a magnetic sensing and recording apparatus.

As described above, since the magnetic substance 20 is provided at the end of the aluminum stranded wire layer 11, the magnetic sensor 21 accurately detects the gap between the end of the ferromagnetic steel clamp 3 and the magnetic substance 20. At the interval δ ₂
Can be measured. In this way, the interval δ ₂ is actually measured, and if the value is as designed, it is sufficient to carry out the retention work. If it is measured that the distance is too narrow, the crimping of the retention clamp is performed again. Correct δ
_The state set to ₂ may be obtained. As a result, it is possible to compress the retaining clamp while confirming the abnormal compression elongation of the aluminum stranded wire layer, which has been a problem in the reverse compression, and it is possible to reliably prevent the occurrence of an accident. Become.

[Effects of the Invention] As described above, according to the compression method of the retention clamp according to the present invention, whether or not there is an abnormality in the compression elongation of the internal aluminum stranded wire layer when the aluminum clamp is compressed using the reverse compression method is appropriately determined. It can be confirmed with certainty, and there is a great significance that the reliability of the reverse compression connection of the folded pattern and the arrest clamp, which is about to increase in the size of the overhead transmission line in the future, can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an initial state of compressing a retaining clamp by the compression method according to the present invention, FIG. 2 is an explanatory view showing a state of the retaining clamp after compression, and FIG. 3 is a point in FIG. FIG. 4 is an explanatory view showing a state where an aluminum clamp is removed inside a chain line circle, FIG. 4 is an explanatory view showing a state in which a distance δ ₂ is measured by a method according to the present invention, and FIG. FIG. 6 is an explanatory diagram showing the configuration, and FIG. 6 is an explanatory diagram showing a situation of occurrence of laughter generated when the retaining clamp is positively compressed. 1: Aluminum clamp, 2: Jumper terminal, 3: Steel clamp, 4: End fitting, 5: Taper, 10: ACSR, 11: Aluminum stranded wire layer, 12: Steel core, 20: Magnetic substance, 21: Magnetic sensor , 22: Magnetic detection and recording device.

Claims (1)

(57) [Claims] 1. An aluminum stranded wire layer in which a stripped steel core is exposed and protruded to connect an anchoring clamp when a compression type anchoring clamp for an overhead transmission line is compressed from a distal end side of the aluminum clamp by a reverse compression method. A magnetic material such as a magnetic steel body or a magnetic powder is installed at the end of the step, and the end of the aluminum stranded wire layer and the end of the steel clamp specified by the magnetic material when the compression of the retention clamp is completed. A method of compressing the transmission line anchoring clamp, wherein a gap between the clamps is detected by a magnetic sensor and whether or not the gap has an appropriate gap is measured.