JPS6338680Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is designed to reduce the abnormal tension when an abnormal tension is applied to the wire by interposing it in the wire holding part, thereby preventing accidents such as wire breakage and tower (utility pole) collapse. This invention relates to an abnormal tension relaxation device that prevents.

Conventionally, when an abnormal condition occurs on a power transmission line or distribution line due to strong winds, snow accumulation, etc., and the wire tension increases abnormally, the wire holding section is A device in which a broken piece (a broken piece that breaks due to a predetermined wire tension) interposed in the electric wire is broken and thereby relieves the abnormal tension, that is, an abnormal tension relaxation device, is known. -1833 etc.

As shown in FIG. 1, such a known device has tension pieces B, B fixed to both ends of a broken piece A, and connecting rods C, C attached to both tension pieces B, B, respectively. Pinned and connected rods C, C
The opposite ends of the wire are connected with pins so as to be flexible at a position separated from the broken piece A. When the change in the wire tension in this known device was precisely observed when the broken piece A was broken, the following was found. It was found that a very large impact load was generated as described in .

That is, when an abnormal tension is applied to the electric wire and the broken piece A breaks, the electric wire becomes in a tension-free state for about 0.2 seconds and falls freely. However, immediately after that, the bent connecting rod stretches, and the tension reaches its maximum value (peak value) when the wire falls the furthest (approximately 0.5 seconds after rupture).
The peak value of this impact load varies depending on the conditions, but
Under certain conditions, the load at break may be even greater than the load at break. Now, if the relationship between wire tension and time at this time is expressed in a graph, it will look like Figure 2.
In the figure, X is the tension at the time of fracture of the fragment, and * is the peak value of the impact load.

Therefore, when using the known device, there was a risk that supporting objects such as electric wires, tension insulators, and steel towers (telephone poles) would be damaged due to the peak value of the impact load.

Therefore, in this proposal, two protection plates are provided in parallel with the broken pieces, the intermediate portions of which are curved in an arcuate shape, and the impact load is alleviated by utilizing the spring action and plastic deformation of the arcuate curved portions of the protection plates. (Reduced peak load)
I decided to do so. The present invention will be specifically explained below with reference to embodiment figures.

In FIG. 3, the abnormal tension relieving device of the present invention, indicated by 1, has a broken piece 5 that is broken by a predetermined wire tension, and is arranged opposite to each other with the broken piece 5 interposed therebetween, and has an arcuate intermediate portion. It consists of two curved (arcuous curved portions 8) protection plates 4, 4, and one end of the protection plates 4, 4 has an electric wire fastener engagement hole 2, 2, and the other end has a tension-resistant insulator. Engagement holes 3, 3 are provided, respectively, and both ends of the broken piece 5 are fixed to protection plates 4, 4.

The broken piece 5 is a strong steel plate with little elongation, and is formed into a dumbbell shape with a narrow center portion, and is preferably galvanized and resin-coated for corrosion protection.

The protective plates 4, 4 are made of a strong and highly elongated steel plate, and are galvanized.

Reference numeral 6 represents an engaging portion for a wire holding device, and 7 represents an engaging portion for a tension insulator.

Riveting is suitable for fixing the broken pieces 5 and the protective plates 4, 4.

The present device 1 has an engaging part 6 (hole 2,
2) is attached to, for example, an electric wire retaining clamp, and the tension insulator engaging portion 7 (holes 3, 3) is used by being attached to the tension insulator.

In this way, when an abnormal tension is applied to the wire and the broken piece 5 breaks, the energy of the wire falling is absorbed by the spring action and plastic deformation of the arcuate curved portions 8, 8 in the protection plates 4, 4. Therefore, the peak value of the impact load is reduced, and therefore a safe wire anchoring portion is obtained in which there is no risk of damage to the wire and its support.

Furthermore, since the broken piece 5 is surrounded and protected by the protective plates 4, 4, there is no risk that the broken piece 5 will come into contact with other objects and be damaged during transportation and construction.
Therefore, it is possible to expect the effect that the breakage will not occur due to a low tension below a predetermined value (the reliability of the breakage strength of the broken pieces will be improved).

[Brief explanation of the drawing]

Fig. 1 is a side view showing a conventionally known abnormal tension relieving device, Fig. 2 is a diagram showing the relationship with wire tension when a fragment of the known device is broken, and Fig. 3 is a perspective view of the abnormal tension relieving device of the present invention. It is. 1... Proposed device, 2... Engagement hole for electric wire fastening device,
3... Engagement hole for tension insulator, 4... Protection plate, 5...
Destruction piece, 8...Arcuate curved part.

Claims (1)

[Scope of utility model registration request] a broken piece that is broken by a predetermined wire tension;
An abnormal tension relieving device consisting of two protective plates that are arranged opposite to each other with a broken piece in between, and whose intermediate portions are curved in an arched shape.