JPH0329954Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an arm for attaching a conductor tension device to a power transmission tower.

Conventionally, this type of arm was attached integrally to the tower body. Therefore, if a difference occurs in the conductor tension between the left and right spans, the difference in tension will act as a bending moment on the arm and the tower main body without being reduced. Therefore, conventional arms and tower bodies are susceptible to wind pressure applied to the conductor, which causes differential tension.
Because the design was designed to have a high safety factor, taking into account icing, snow, and other variable loads, the transmission tower was large and production costs were high.

In view of the above points, the present invention is designed to reduce or eliminate the bending moment applied to the arm and the tower body by providing the arm with a bending moment reduction function, and aims to provide a lightweight and economical power transmission tower. It is said that

In order to achieve this objective, in the present invention, each arm piece is horizontally rotatably attached to two adjacent posts of the tower main body, and the tips of both arm pieces are connected via a connecting member to form a trapezoidal shape. A quadrilateral link mechanism is constructed, and mounting fittings for attaching conductor tension devices are provided at both ends of the connecting member, respectively.

The present invention will be explained below based on embodiments shown in the drawings. Flanges 3 are fixed to two adjacent main columns 2 of a steel tower body 1, respectively. An arm piece 4 is attached to each flange 3 so as to be horizontally rotatable via a support shaft 5, and the other ends of both arm pieces 4 are pivotally attached to both ends of a pair of upper and lower connecting plates 6 via a support shaft 7, thereby providing an overall structure. A trapezoidal quadrilateral link mechanism is constructed. At both ends of the pair of connecting plates 6, bearings 9 formed at both the upper and lower ends of the yokes 8 are pivoted by support shafts 10, so that the yokes 8 are horizontally rotatably attached to the connecting plates 6. Furthermore, a through hole 11 is formed in the center of the yoke 8 for attaching a conductor tension device (not shown).

Since this embodiment has the above-mentioned configuration, as shown in FIG. When the conductor tensions are equal, the differential tension is zero, the bending moment is zero, and the quadrilateral link mechanism is in a statically stable state. Now, when a difference occurs in the conductor tension between the left and right spans, for example, when the tension on the right conductor becomes greater than the tension on the left conductor in the figure, each arm piece 4 rotates to the right in the figure.
This causes the right conductor to relax and reduce tension, and the left conductor to pull and increase tension.
As a result, when the bending moments P _{2 2} and P _{3 3} of the two become equal, the arm piece 4 and the connecting plate 6 stop on the imaginary line. The bending moment for both is P _{3 3}
>P _{2 2} , arm piece 4 continues to rotate to the right in the figure, but the left arm piece 4
When the connecting plate 6 and the connecting plate 6 reach a position where they are aligned in a straight line as shown in FIG. 4, the right arm piece 4 is prevented from rotating, so at this point the rotation of the quadrilateral link mechanism stops even if there is a difference in bending moment. . Therefore, the problem of the arm piece 4 swinging out is eliminated, and abnormal approach of the conductor to the tower body can be prevented.

The above was an explanation of the operation when the right conductor tension is greater than the left conductor tension, but if the left conductor tension is greater than the right conductor tension, the same effect as described above will occur, only the direction of one rotation of the arm will be reversed. can get.

Although the arm pieces are straight beams in this embodiment, they may be V-shaped or other shapes.
The set of connecting plates may be an integral connecting body.

As explained above, in the present invention, the two arm pieces constitute a trapezoidal quadrilateral link mechanism with the two posts of the tower main body and the connecting member, so if a bending moment occurs in this, the bending The arm piece rotates in a direction that reduces the moment, reducing or eliminating the bending moment. Therefore,
Compared to conventional power transmission towers, it has the advantage of being lighter and lowering production costs. Furthermore, since the quadrilateral link mechanism stops when the arm piece rotates to a predetermined angular position regardless of the presence or absence of a bending moment, abnormal approach of the conductor to the tower body can be prevented.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a plan view, Fig. 2 is a side view, Fig. 3 is a view taken in the direction of arrow A in Fig. 1, and Fig. 4 shows one arm piece being extended to its maximum extent. FIG. 3 is a plan view showing a rotated state. 1... Steel tower main body, 2... Main pillar, 4... Arm piece, 6... Connecting plate.

Claims (1)

[Scope of utility model registration request] Each arm piece is horizontally rotatably attached to two adjacent posts on the tower main body, and the tips of both arm pieces are connected via a connecting member to form a trapezoidal quadrilateral link mechanism. A swinging arm for a power transmission tower, characterized in that mounting brackets for attaching conductor tension devices are provided at both ends.