JP3152378B2 - Compression type clamp and prefabricated electric wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression type clamping clamp used for retaining an electric wire such as a transmission line made of steel core aluminum stranded wire to a tension tower, and a prefabricated electric wire provided with the retaining clamp.

[0002]

2. Description of the Related Art When a steel core aluminum stranded wire having a two-layer structure of a steel core serving as a tension member and an aluminum stranded wire serving as a current passage is used as an electric wire such as an overhead power transmission line, the steel core aluminum stranded wire (hereinafter referred to as "wire") is used. In order to hold the electric wire) to the tension tower, a compression type clamping clamp composed of a steel clamp and an aluminum sleeve is used in correspondence with the double-layer structure of the steel core aluminum stranded wire. This type of general compression clamp has a so-called JEC type structure in which a lug for connecting a jumper socket largely protrudes substantially perpendicularly from the end of the aluminum sleeve.

[0003] By the way, for the purpose of labor saving in overhead wire construction, the span of a steel tower to be installed is measured in advance precisely,
Prefabricated wire, which measures the length precisely taking into account the sag of the wire to be installed at the factory, and compresses and fixes compression type clamps at both ends of the wire to form a prefabricated wire. The overhead wire construction method is known. When this prefabricated electric wire is extended, a wire rope is connected to a compression type anchor clamp at the end of the electric wire, and a wire wheel suspended from a tower arm is passed through. Since the lug portion is difficult to pass through the wheel, the lug portion 9 is provided along the aluminum sleeve 3 and does not protrude much, as shown in FIGS. A retaining clamp 1 is used. Also, as shown in the figure, to reduce the damage of the wire due to the sharp bending of the wire at the base of the clamp (left end in FIG. 8) when passing through the wheel, the entire length of the compression-type clamp is electrically and mechanically reduced. A structure that is as short as possible within a range that satisfies the required performance is used. The details of the conventional compression type clamping clamp 1 will be described. 2 is a steel clamp, 3 is an aluminum sleeve, and the steel clamp 2 is
A corrugated portion 5 for firmly connecting the steel sleeve portion 4 and the aluminum sleeve 3 that are compression-fixed on the exposed steel core at the end of the electric wire, and a watertightness between the steel clamp 2 and the aluminum sleeve 3 The aluminum sleeve 3 has a structure in which a tapered contact portion 6 and a retaining portion 7 for retaining to a steel tower are integrally formed. On the other hand, the aluminum sleeve 3 extends over the outer periphery of a portion except for the aluminum wire portion of the electric wire and the retaining portion 7 of the steel clamp 2. An aluminum sleeve main body 8 to be compressed and fixed, and a plate-shaped lug 9 integrally provided along the aluminum sleeve main body 8 on the retaining end side (right side in FIG. 8) of the aluminum sleeve main body 8. I have.
The compression type clamp 1 is about 80% shorter than the JEC compression clamp described above.

Then, the above-mentioned compression type clamp 1 is compression-fixed to both ends of a precisely-sized electric wire to form a prefabricated electric wire. At this time, an aluminum sleeve 3 is inserted in advance around the aluminum wire portion of the electric wire. After the steel sleeve 4 of the steel clamp 2 is compression-fixed on the exposed steel core at the end of the electric wire, the aluminum sleeve 3 is compression-fixed over the outer circumference of the steel sleeve 4 and the outer circumference of the aluminum wire. And the steel clamp 2 and the aluminum sleeve 3 are integrated. After extending the prefabricated electric wire, a jumper socket 11 having a forked tip is fitted into the lug 9 as shown by a two-dot chain line in FIGS.

[0005] The above-mentioned conventional wheel-passage-type compression-type clamp 1 is designed from the viewpoint of simply satisfying the electrical and mechanical performances of the compression-type clamp. 2 indicates that the steel sleeve portion 4 has the entire length of the compression type clamp 1 (aluminum sleeve 3).
From the mouth to the center of the connection hole 7a of the retaining part 7) L
Had a length that did not reach the central portion M.

[0006]

In the drawing work of the prefabricated electric wire in which the compression type anchor 1 is compressed and fixed as described above, the compression type anchor 1 passes through the wheel 12 as shown in FIG. At this time, as shown in FIG. 11, the compression type clamping clamp 1 receives a vertical component T _V due to the extension tension T of the electric wire 13 and the wire rope 14, and the central portion M of the compression type clamping clamp 1 is moved. It will be bent from both sides as the center. In this case, the point where the maximum bending moment occurs is in the central part M, whereas the tip of the steel clamp 2 has a length that does not reach the central part of the compression-type anchoring clamp 1 as described above. Since the portion on the side of the electric wire 13 from M is only the low-strength aluminum sleeve 3, depending on the extension tension and catenary angle, the aluminum sleeve 3 may be bent due to plastic deformation due to the extension tension. For this reason, when using this kind of the compression pulling clamp 1 of a metal wheel passing type, it is necessary to limit the extension wire tension and the catenary angle. Also, in order to prevent bending of the compression type clamp 1 due to plastic deformation, the main part is made of high-strength special steel, and the part on the wire side is compressed into a rubber protector made of rubber to protect the wire from bending. Although a method of accommodating the mold retaining clamp 1 and passing the wheel through the wheel has also been put into practical use, in this method, the work of attaching and detaching the clamp protector is complicated, and the work of removing the clamp protector is connected to the upper part of the steel tower. Since it is necessary to perform the operation at the tip end of the tension insulator series and it is not easy, there is a disadvantage that the number of steps is remarkably increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional drawbacks, and can improve the strength of the compression-type anchor clamp against the maximum bending moment due to the vertical component force of the extension wire tension when passing through a wheel. An object of the present invention is to provide a compression-type clamp which can prevent bending due to plastic deformation of the compression-type clamp without requiring a clamp protector, and a prefabricated electric wire provided with the compression-type clamp.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a compression type clamping clamp according to the present invention comprises: a steel sleeve portion which is compression-fixed on the outer periphery of a steel core at the end of a wire made of aluminum stranded steel core; A compression clamp, comprising: a steel clamp having at least a retaining portion for retaining; and an aluminum sleeve compression-fixed over the outer periphery of the aluminum wire portion of the electric wire and a portion excluding the retaining portion of the steel clamp. clamp the steel Sri steel sleeve extension is fitted into any of the aluminum wire inner portion except for the aluminum wire portion outermost layer of the electric wire without the steel sleeve portion concentric with the tubular
And the steel sleeve extension extends at least to a position beyond the central portion of the entire length of the compression type retaining clamp.

[0009]

When a prefabricated electric wire in which the above-mentioned compression type clamp is compressed and fixed to an electric wire is extended, when the compression type clamp passes through the wheel, the compression type clamp is applied to the wire tension of the wire and the wire rope. The maximum bending moment is generated in the central part by the vertical component force. However, in this center there is a steel sleeve extension of the steel clamp,
Since the high-strength steel sleeve extension bears the maximum bending moment, bending due to plastic deformation of the aluminum sleeve can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a compression type clamp 21 according to an embodiment of the present invention, and FIG. 2 is a right side view of the same. FIG. 3 is a front view showing only a later-described steel clamp 22 in the compression type retaining clamp 21. The compression type clamp 21 comprises a steel clamp 22 and an aluminum sleeve 23. The steel clamp 22 has a hole 2 for inserting a steel core of an electric wire.
4a, a steel sleeve portion 24 compressed and fixed on the exposed steel core at the end of the electric wire made of a steel core aluminum stranded wire, a corrugated portion 25 for firmly connecting the aluminum sleeve 23,
The configuration in which the tapered contact portion 26 for achieving water tightness between the steel clamp 22 and the aluminum sleeve 23 and the retaining portion 27 for retaining the steel tower integrally are the same as the conventional one. At the end of the steel sleeve portion 24, a steel sleeve extension portion 32 which has a cylindrical shape concentric with the steel sleeve portion 24 and is fitted into any aluminum wire inner layer portion except the outermost aluminum wire portion of the electric wire is integrally provided. At the same time, the steel sleeve extension 32 extends at least to a position exceeding the central portion M of the entire length L of the compression type clamping (distance from the mouth of the aluminum sleeve 23 to the center of the connection hole 27a of the retaining portion 27). The steel sleeve extension 32 is an uncompressed portion and is simply put on the steel core of the electric wire. Since the steel core must penetrate the steel sleeve extension 32, the diameter of the through hole 32 a is equal to the hole 24 of the steel sleeve 24.
a or slightly larger than the diameter of “a” (same in the illustrated example), and it is necessary to fit the wire into the inner layer of the aluminum wire excluding the outermost layer of the aluminum wire. The same as the outer diameter. The structure of the aluminum sleeve 23 is basically the same as that of the conventional one, and is a cylindrical aluminum sleeve main body which is covered and compressed and fixed over the outer periphery of the portion except for the aluminum wire portion of the electric wire and the retaining portion 27 of the steel clamp 22. A part 28 and a plate-shaped lug part 29 integrally provided along the aluminum sleeve body part 28 on the retaining end side of the aluminum sleeve body part 28.
A tapered portion 28a is formed near the tip of the aluminum sleeve main body 28, and a jumper socket 1 is formed on the lug 29.
A connection hole 29a for connecting the first and second holes 1 is formed. Also,
In order to increase the strength of the compression type clamp, the outer diameter of the aluminum sleeve main body portion 28 and the outer diameter of the steel sleeve portion 24 of the steel clamp 22 are increased by a conventional JEC type compression type clamp. Compared to the clamp,
It is about 1.4 to 1.8 times.

FIG. 4 is a longitudinal sectional view showing a stepped-off structure of an electric wire 31 made of a steel core aluminum stranded wire to which the above-mentioned compression type clamping clamp 21 is compressed and fixed. As shown, this wire 31
Aluminum wire portion 31 composed of, for example, three layers on the outer periphery of steel core 31a
The steel core 31a passes through the through hole 32a of the steel sleeve extension 32,
The external aluminum wire portion 31b is cut and removed so as to be inserted all the way to the end of FIG. In this case, 2 of the aluminum wire portion 31b
The layer and the outermost layer are cut at a position near the tip of the steel sleeve portion 24 in consideration of the compression and elongation of the steel sleeve portion 24,
The first layer of the aluminum wire portion 31b is cut and removed to a length where a hollow portion 31c into which the steel sleeve extension 32 can be fitted is formed.

When the above-mentioned compression clamp 21 is compression-fixed to the electric wire 31, the aluminum sleeve 23 is
The steel core 31a of the electric wire 31 is inserted through the through hole 32a of the steel sleeve extension 32 of the steel clamp 22 and inserted into the hole 24a of the steel sleeve portion 24 in a state where the steel core 31a is slid into the back of the aluminum wire portion 31b. After inserting, the steel sleeve portion 24 is compressed (the steel sleeve extension portion 32 is not compressed), and the steel sleeve portion 24 is compressed and fixed on the steel core 31a, and then the aluminum sleeve 23 is slid to the outer periphery of the steel clamp 22. Then, the steel clamp 22 and the aluminum sleeve 23 are integrated by compressing and fixing over the steel clamp 22 and the aluminum wire portion 31b. When the compression type clamping clamp 21 is compressed and fixed to both ends of the fixed-length cut electric wire 31 as described above, a prefabricated electric wire is obtained. After extending the prefabricated electric wire, the jumper socket 11 having a forked tip is fitted into the lug portion 29 as shown by a two-dot chain line in FIGS.

As shown in FIG. 5, when the prefabricated electric wire 33 in which the compression type retaining clamp 21 is compressed and fixed to both ends of the electric wire 31 in the manner described above, the compression type retaining clamp 21
2, the compression type clamp 21 is connected to the electric wire 31 and the wire rope 14 as described with reference to FIG.
Receiving a vertical component force T _V by extending line tension T of the maximum bending moment occurs at the central portion M. However, the steel sleeve extension 32 of the steel clamp 22 is present at the central portion M, and since the high-strength steel sleeve extension 32 bears the maximum bending moment, bending of the aluminum sleeve 23 due to plastic deformation can be prevented. . Therefore, it is not necessary to use a clamp protector as in the related art.

FIG. 6 shows another embodiment of the steel clamp 22A in the compression type clamp according to the present invention. The steel clamp 22A has a steel sleeve extension 42 formed in two stages, a first stage 42a and a second stage 42b. In this case, the first stage 42a of the steel sleeve extension 42 is extended to the central portion M of the entire length L of the compression type clamping clamp. Thereby, the strength of the compression type clamp can be further improved. Other points are the same as those described above. In this case, as shown in FIG. 7, when the steel core 41a of the electric wire 41 is exposed, the first and second layers of the aluminum wire portion 41b are connected to the first and second stages 42a and 42a of the steel sleeve extension 42. 4
2b is cut and removed so that a two-stage hollow portion 41c is formed. When a large-sized steel core aluminum stranded wire having a multi-layered aluminum wire portion is used, it is possible to form three or more stages of steel sleeve extensions.

[0015]

According to the present invention, the extension of the steel sleeve provided integrally with the steel clamp extends to a position beyond the center of the entire length of the compression type clamping clamp. The strength against the maximum bending moment due to the vertical component force of the wire tension can be improved, and the bending due to the plastic deformation of the compression type clamp can be effectively prevented without the need for a clamp protector.

If the prefabricated wire construction method is performed using the prefabricated electric wire according to the second aspect, it is not necessary to use a clamp protector, so that the efficiency of the prefabricated electric wire drawing operation is remarkably improved.

[Brief description of the drawings]

FIG. 1 is a front view of a compression type clamp according to an embodiment of the present invention.

FIG. 2 is a right side view of FIG.

3 (a) is a front view showing only the steel clamp in FIG. 1, and FIG. 3 (b) is a left side view thereof.

FIG. 4 (a) is a longitudinal sectional view of an electric wire made of a steel core aluminum stranded wire to which the above-mentioned compression type clamping clamp is compression-fixed, and FIG. 4 (b) is a right side view.

FIG. 5 is a front view showing a state in which the compression type clamp is passing over the wheel while the prefabricated electric wire to which the compression type clamp of the above embodiment is attached is drawn.

6 (a) and 6 (b) show another embodiment of the steel clamp in the compression type retaining clamp of the present invention, wherein FIG. 6 (a) is a front view and FIG. 6 (b) is a left side view thereof.

FIG. 7 is a longitudinal sectional view of an electric wire made of a steel core aluminum stranded wire to which a compression type retaining clamp having the steel clamp of FIG. 6 is compression-fixed.

FIG. 8 is a front view showing a conventional compression type anchor clamp.

FIG. 9 is a right side view of FIG.

FIG. 10 is a front view showing a state in which the compression type clamp is passing over a wheel while the prefabricated electric wire to which the compression type clamp is attached is shown in FIG. 8;

FIG. 11 is a view for explaining the force acting on the compression type clamp during the wire drawing process of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Compression type clamping clamp 22, 22A Steel clamp 23 Aluminum sleeve 24 Steel sleeve part 24a Hole 25 Corrugated part 26 Adhesion part 27 Retention part 27a Connection hole 28 Aluminum sleeve body part 29 Lug part 31 Electric wire (steel core aluminum stranded wire) 31a Steel core 31b Aluminum wire part 32 Steel sleeve extension part 32a Through hole 33 Prefabricated electric wire L Full length of compression type clamping clamp M Central part of compression type clamping clamp

Continuation of front page (56) References JP-A-6-70481 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02G 1/02

Claims (2)

(57) [Claims] 1. A steel clamp having at least a steel sleeve portion compression-fixed on the outer periphery of a steel core at the end of a wire made of a steel core aluminum stranded wire and a retention portion for retaining the wire.
In a compression type retention clamp comprising an aluminum wire portion of the electric wire and an aluminum sleeve compressed and fixed over the outer periphery of a portion excluding the retention portion of the steel clamp, the steel clamp has a cylindrical shape concentric with the steel sleeve portion. the steel sleeve portion a steel sleeve extension is fitted into any of the aluminum wire inner portion except no aluminum wire portion outermost layer of the wire
And a steel sleeve extension extending at least to a position beyond the center of the entire length of the compression type clamp. . 2. A prefabricated electric wire obtained by compressing and fixing the compression-type anchoring clamp according to claim 1 to both ends of an electric wire made of a steel core aluminum wire, wherein the steel at the end of the electric wire made of a steel core aluminum twisted wire. When exposing the core by cutting and removing the aluminum wire part, cut and remove any inner tank part excluding the outermost layer of the aluminum wire part farther than the cut end position of the outermost layer and put it inside the outermost layer A hollow portion is formed, and the steel sleeve portion is compression-fixed to the steel core in a state where the steel sleeve extension of the compression type clamp is inserted into the hollow portion, and then the aluminum sleeve is placed on the steel sleeve portion and the aluminum wire portion. A prefabricated electric wire characterized by being compressed and fixed over the entire length.