JPH0332693Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an arm for attaching a tension insulator device to a power transmission pole on which a relatively small-sized power transmission line (customer line) with a transmission voltage of about 20,000 to 60,000 V is installed. be.

Conventional arms of this type have generally been integrally attached to a column. 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 support column without being reduced. Therefore, conventional arms and poles are designed with a high safety factor, taking into account variable loads such as wind pressure, icing and snow that are applied to the conductor that cause differential tension, and as a result, transmission poles are large and manufacturing costs are high. There was a problem with that. On the other hand, the arm is made up of two rod-shaped insulators and a connecting fitting, and the arm can be pivoted to the steel tower only in the direction of the railway line (Jikko Sho 41).
-5718 Publication) has been proposed. However, with this one, there was a risk that the electric wire could come abnormally close to the steel tower if the arm broke off.

In view of the above-mentioned points, an object of the present invention is to provide a swinging arm for a power transmission pole that can provide the arm with a bending moment reducing function and eliminate abnormal proximity between the wire and the pole.

In order to achieve this purpose, in the present invention, an arm with tension insulators attached to both sides of the tip is attached to the column so as to be rotatable left and right by means of two upper and lower spindles provided at its base. It is characterized in that an offset amount is taken in the direction in which the arm protrudes, and the hole for attaching the support shaft near the tip of the arm is formed into an arcuate hole of a predetermined length with the axis of the support shaft near the column as the center of the arc.

The present invention will be described below based on embodiments shown in the drawings. A pair of flanges 2, 2 are provided on the top and bottom of the support column 1, respectively, and bearing parts 4, 5 provided on the top and bottom of the base of the arm 3 are fitted into these pair of flanges 2, 2, and the flanges 2, 2 are fitted with the support shafts 6, 7. 2, it is attached so that it can rotate left and right. The support shaft 6 and the support shaft 7 have an offset amount ΔL in the arm protrusion direction, and in the embodiment, the support shaft 6 is positioned in front of the support shaft 7,
The hole of the flange 2 into which the support shaft 6 is fitted is a circular arc hole 8 whose arc center is the axis of the support shaft 7.
The length of the conductor is selected to prevent the conductor from approaching the pillar 1 abnormally due to the rotation of the arm 3, and the arm rotation angle is limited.

In addition, in this embodiment, the arm 3 has a lower beam 9 provided with the bearing portion 5 and an upper beam 10 provided with the bearing portion 4, which are connected at the tip via a connecting member, and are reinforced with ribs 14. A connecting plate 12 having tension-resistant insulator device mounting holes 11 bored on both sides and a tension fitting 13 are fixed to the lower surface of the tip.

Since this embodiment has the above-mentioned configuration, when the conductors are stretched on both sides of the connecting plate 12 via tension-resistant insulators (not shown), the tension of the left and right conductors acting on the connecting plate 12 is reduced. When they are equal, no bending moment acts on the arm, so arm 3
is at rest. Now, in Figure 2, for example, the tension on the right conductor is greater than the tension on the left conductor,
When the arm 3 rotates to the right in the figure due to the differential tension, the support shaft 7 attached to the upper beam 10 is rotated through the arc hole 8.
slide on top. As a result of this clockwise rotation, the right conductor is relaxed and its tension decreases, and the left conductor is stretched and its tension increases, so that the differential tension gradually decreases. Therefore, in the normal case, the arm 3 stops before the support shaft 6 comes into contact with the edge of the circular arc hole 8. In addition, even if the arm 3 continues to rotate due to the large differential tension, the rotation of the arm 3 will stop when the support shaft 6 comes into contact with the end of the arcuate hole 8, eliminating the problem of the arm swinging out and preventing abnormalities between the support and the conductor. Access can be reliably prevented.

The above case was for the case where the right conductor tension was greater than the left conductor tension, but even when the left conductor tension is greater than the right conductor tension, the same effect as described above can be obtained by simply reversing the arm rotation direction.

In this embodiment, the support shaft 6 is arranged closer to the arm tip than the support shaft 7, but this arrangement may be reversed to form an arcuate hole in the lower flange 2 in which the support shaft 7 slides. .

As explained above, according to the present invention, the two upper and lower support shafts for attaching the arm to the column so as to be rotatable left and right have an offset amount in the arm protrusion direction, and the hole for attaching the support shaft closer to the tip of the arm is located closer to the column. The shaft is formed into an arc hole of a predetermined length with the axis of the support shaft as the center of the arc, so when a difference in conductor tension occurs between the left and right spans, the arm rotates in the direction to reduce the difference in tension, reducing the bending moment. In addition, since the rotation of the arm stops when the support shaft reaches the end of the circular arc hole, there is the practical benefit of reliably preventing abnormal approach of the conductor to the pillar.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a side view and FIG. 2 being a plan view. 1... Support column, 3... Arm, 6, 7... Support shaft,
8...Circular hole, 11...Tension-resistant insulator device mounting hole.

Claims (1)

[Scope of utility model registration request] An arm with tensile insulators attached to both sides of the tip is attached to the column so that it can rotate left and right by means of two upper and lower spindles provided at its base.Both spindles are offset in the direction of arm protrusion, and 1. A swinging arm for a power transmission pole, characterized in that a hole for attaching a supporting shaft closer to the pillar is formed as an arcuate hole of a predetermined length with the axis of the supporting shaft closer to the pillar as the center of the arc.