JPH11127532A - Arm device for steel tower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arm device for steel tower which can sufficiently absorb tension applied to a steel tower for transmission line from an electric cable, and with which an electric cable for transmitting a boosted current can be stringed on the steel tower by using the line width of a suspension steel tower, before boosting. SOLUTION: Two sets of rigid trusses, each composed of an upper arm 5 and a lower arm 4 which form a triangle with a steel tower 1 for transmission line, are attached to the steel tower 1 in such a way that the trusses are in a rotatable state around nearly vertical base-section hinge shafts 6b of the tower 1, and the intersections between the upper and lower arms 5 and 4 are connected with a connecting arm 7, which is shorter than the distance between the base sections of the lower arms 4 through hinges. Then the corresponding end sections 3a and 3b of electric cables are respectively connected to both the end sections of the arm 7 via tension insulators 9a and 9b, and the corresponding end sections 3a and 3b of the electric cables are connected to each other via a jumper line 3c making a detour around the arm 7 and insulators 9a and 9b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission tower, and more particularly, to an electric wire insulation and support structure.

[0002]

2. Description of the Related Art As is well known, in the case of power transmission with a relatively low voltage, a suspension tower having a structure as shown in FIG. 5 is used.
That is, the suspension tower A designed for 60,000 volts is constructed of an angle material or the like, and a plurality of arms a _{1 to} a ₄ having a rigid rigid frame structure are formed on an upper portion thereof. arm a ₁ suspended on the tip of ~a ₄ insulators B ₁ .about.B ₄
, The electric wires C ₁ and C ₂ having the electric wire width W are suspended, respectively.

[0003]

[SUMMARY OF THE INVENTION That is, in the suspension tower A in such a structure, keeping the line width W required length of the arm a ₁ ~a ₄ and suspension insulators B ₁ .about.B ₄ Since the structure absorbs the unbalanced tension from the electric wires C ₁ and C ₂ applied to the tower due to the swing shown by the imaginary line, the required rigidity of the tower itself is small and the line width is relatively small. Since the electric wire is insulated only by the suspension insulators B _{1 to} B _4, there is a problem that a 60,000 volt line cannot be boosted to 154 KV.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the conventional suspension tower, the object of the present invention is to sufficiently absorb the tension from the electric wire applied to the power transmission tower, to use the conventional line width, and to boost the voltage. To get the tower arm device.

[0005]

SUMMARY OF THE INVENTION To this end, the present invention provides two sets of rigid trusses comprising an upper arm and a lower arm forming a triangle with a power transmission tower. The power transmission tower is supported in a rotatable state about a substantially vertical base hinge axis, and the intersection between each upper arm and the lower arm is hinged with a connecting arm shorter than the distance between the bases of the lower arms. A steel tower which is connected to the corresponding ends of the electric wires via tensile insulators at both ends of the connecting arm, respectively, and the corresponding ends of the electric wires are connected by jumper wires which bypass the connecting arm and both the tensile insulators. An arm device is proposed.

In the following description of a preferred embodiment of the present invention, 1) the lower arm is extended in a substantially horizontal direction, and the upper arm is lowered obliquely downward from a base thereof to form a rigid body having a substantially right triangle shape. 2) The jumper line is a structure that is maintained in a substantially horizontal state with an interval insulator that connects the intermediate portion and the transmission tower in an oblique direction. 3) The tension insulator and the interval insulator. At least one is
A structure composed of a composite insulator is described.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 shows the upper part of a power transmission tower 1 to which the present invention has been applied. Four tower arm devices 2A, 2B, 2C and 2D according to the present invention are mounted on the left and right of the power transmission tower 1, respectively. The electric wires 3A, 3B, 3C, 3D are suspended by the 2B, 2C, 2D.

That is, each of the tower arm devices 2A, 2B, 2
Since the structures of C and 2D are the same, the tower tower arm device 2A at the upper right will be described as a whole as a representative. ing. In the case of the illustrated embodiment, the lower arm 4 and the upper arm 5 whose bases are connected to the power transmission tower 1 with the base hinge shafts 6a and 6b in the substantially vertical direction constitute a rigid truss having a substantially right-angled triangle. Is extended substantially in the horizontal direction, and the tip of the lower arm 4 intersects the tip of an upper arm 5 that extends diagonally downward from the base joined by a base hinge bracket 6.

[0009] Then, between the tips of each pair of the lower arm 4 and the upper arm 5 is connected to each other by means of a connecting arm 7 of the distance L ₁ is shorter than the length L ₂ between the base of the lower arm 4. That is, the distal ends of the lower arm 4 and the upper arm 5 and the corresponding ends of the connecting arm 7 are substantially perpendicular to the distal hinge shafts 8a, 8a.
Since the hinges are connected by b, the support portion formed by the two rigid trusses can be integrally deformed in the horizontal plane.

In the present invention, the corresponding ends 3a and 3b of the electric wire 3A are retained at both ends of the connecting arm 7 via the tension insulators 9a and 9b, respectively.
The arc-shaped jumper wire 3c connecting between the wires 3a, 3b is maintained in substantially the same horizontal plane as the electric wires 3A, 3B, 3C, 3D by using a long interval insulator 10. In other words, the spacing insulator 10 pivotally supports the base to the power transmission tower 1 by the hinge bracket 11 below the lower arm 4, and the distal end thereof is connected to the middle part of the jumper wire 3c using the fixing bracket 12. At the same interval, the jumper wire 3c and the connecting arm 7 are maintained apart from the power transmission tower 1.

Although illustration is omitted, in the case of the illustrated embodiment, the above-described tension insulators 9a and 9b and the spacing insulator 10 are composed of a composite insulator having an insulating resin creeping discharge umbrella attached to the outer periphery of the FRP. , And can be manufactured inexpensively.

As is apparent from the above description, in the tower arm device according to the illustrated embodiment, the electric wire
Since A, 3B, 3C and 3D are retained by the tension insulators 9a and 9b on both sides of the connecting arm 7, even if the line width W is the same as that of the conventional 60,000 volt suspension tower shown in FIG. It is possible to cope with a high voltage of 150,000 volts only by increasing the length of the tensile insulators 9a and 9b. In other words, the transmission tower 1 in the illustrated example has the same line width as the suspension tower shown in FIG. 5, so that the land width of the line is equivalent to the case of 60,000 volts.

Further, when the storm occurs, the corresponding end 3 of the electric wire 3A may be used.
When the unequal tension is applied to the a and 3b and the 3a side is higher in tension than the 3b side, the lower arm 4, the upper arm 5, and the connecting arm 7 are displaced as shown in FIG. The power transmission tower 1 is prevented from acting on. FIG.
Fig. 4 shows a case where uneven tension is applied to the corresponding end 3a of the electric wire 3A in the upward direction in the figure. In this case, the lower arm 4 and the upper arm 5 are connected to the base hinge shafts 6a and 6b.
And the rigid truss is connected by the connecting arm 7 so that a part of the same tension is applied to the corresponding end 3b of the electric wire 3A on the lower side in the figure, The uneven tension between the portions 3a and 3b is reduced, and the abnormal tension is prevented from being directly applied to the power transmission tower 1. The L ₂ since shorter than L ₁ This displacement insulator stops at up to a certain place 9b is prevented from impinging on the tower.

[0014]

As is apparent from the above description, according to the tower arm device of the present invention, a structure can be obtained in which the line width of the power transmission tower is small and high-voltage electric wires can be installed. That is,
In the tower arm device of the present invention, it is possible to obtain a transmission line in which the line width is equal to that of the conventional suspension tower, and the power transmission capacity is increased by using the suspension tower.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view of a main part of a transmission tower according to the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of the transmission tower.

FIG. 3 is an enlarged horizontal sectional view of a main part of the transmission tower.

FIG. 4 is a view similar to FIG. 3 when receiving a biased tension;

FIG. 5 is an enlarged perspective view of a main part of a conventional suspension tower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission tower 2A-2D Tower arm device 3A-3D Electric wire 3a, 3b Corresponding end 3c Jumper wire 4 Lower arm 5 Upper arm 6 Base hinge bracket 6a, 6b Base hinge shaft 7 Connection arm 8a, 8b Tip hinge shaft 9a, 9b Tensile insulator 10 Spacing insulator 11 Hinge bracket 12 Fixing bracket

Claims (4)

[Claims] 1. A two-piece rigid truss comprising an upper arm and a lower arm forming a triangle with a power transmission tower is rotatable about a substantially vertical base hinge axis of the power transmission tower. As a support on the transmission tower, the intersection between each upper arm and the lower arm is hinged with a connecting arm shorter than the distance between the bases of the lower arms, and a tension insulator is attached to each end of the connecting arm. And a corresponding end of the electric wire is connected to the corresponding end of the electric wire via a jumper wire that bypasses the connecting arm and both the tension insulators. 2. The truss according to claim 1, wherein said lower arm extends substantially horizontally and said upper arm is lowered obliquely downward from a base thereof to form a substantially right triangle triangular rigid truss. Tower arm equipment. 3. The tower according to claim 1, wherein the jumper line is maintained substantially horizontal by an interval connecting an intermediate portion thereof and a power transmission tower in an oblique direction. Arm device. 4. The tower arm device according to claim 1, wherein at least one of the tension insulator and the interval insulator is formed of a composite insulator.