JPH0135572B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lashing wire used for bundling cables along an installed overhead line, and a cable installation method using the same.

For example, when attaching cables such as optical cables and telecommunications cables to overhead lines such as installed overhead ground wires and messenger wires, and binding them with lashing wires, conventionally, lashing wires without bends were used. The binding was done by winding it spirally using a thinning machine.

However, if the lashing wire is wound with a lashing machine, it is not possible to tighten the overhead wire and the cable to a certain degree of tightness. For this reason, the cable is prone to slack, and in such a situation, when strong winds blow, the cable vibrates and repeatedly hits the overhead line, causing damage to the internal optical fibers in the case of optical cables. There were flaws. Further, in the case of telecommunication cables, cable fatigue is accelerated. In addition, with conventional lashing wires wrapped with a lashing machine, if the lashing wires are cut for some reason, the lashing wires will unwind and the cable will hang down. There were disadvantages in that the lashing wires were easily damaged and the lashing wires hung down, causing short circuits.

In order to avoid such drawbacks, it is possible to wrap a lashing wire that has been bent into a spiral shape in advance, but long lengths cannot be wrapped with such spiral lashing wires, and short lengths cannot be wrapped. It had the disadvantage that it was very time-consuming to wind the wire.

An object of the present invention is to provide a lashing wire that can bind overhead wires and cables with a certain degree of tightness, that will not unravel even if cut, and that can be easily wrapped around long lengths. The purpose of the present invention is to provide a method for constructing a cable using the present invention.

The lashing wire according to the present invention is characterized in that it is made of a shape memory alloy wire whose shape has been memorized in a spiral shape and made into a straight line.

The cable installation method using the lashing wire according to the present invention involves attaching the cable to the installed overhead wire, and adding the following to the outer circumference of the overhead wire and the cable.
A lashing wire made by straightening a shape memory alloy wire whose shape has been memorized into a spiral shape is wound spirally at approximately the same pitch as the memorized spiral pitch, and then the lashing wire is heated to form a spiral shape. The method is characterized in that the above-mentioned overhead wire and cable are tightened after returning to the memorized state.

Embodiments of the present invention will be described in detail below with reference to the drawings. The lashing wire 1 of this embodiment is made by straightening a shape memory alloy wire having a circular cross section and having been memorized in a spiral shape. Examples of shape memory alloys include Ni-Ti, Ni-Al, Cu-Al-
A thermoelastic type alloy that undergoes martensitic transformation, such as Ni or Cu-Al-Zn, is used. The lashing wire 1 made of such a shape memory alloy wire has a diameter of 60 to 90% of the outer diameter D of the overhead wire 2 and cable 3 to be wrapped around the shape memory alloy wire as shown in FIG.
It can be obtained by bending it into a helical shape with an inner diameter of , and at approximately the same pitch as the pitch during lashing, allowing it to memorize the shape at a high temperature (e.g. 500°C to 1000°C), and then stretching it into a straight line. . The lashing wire 1 stretched into a straight line is transported by winding it around a drum or the like, and is used for winding.

The cable construction method using the lashing wire 1 made of such a shape memory alloy wire is described in the third section.
As shown in the figure, an overhead line 2 such as an overhead ground wire or messenger wire is installed in advance, and a cable 3 such as an optical cable or telecommunications cable is attached to it, and a lashing machine or the like is attached to the outer periphery of both lines. Then, the lashing wire 1 made of the shape memory alloy wire of the present invention is spirally wound at substantially the same pitch as the shape memory pitch P. After the winding of the lashing wire 1 is completed, the lashing wire 1 is heated to return it to its memorized spiral state. In this way, the latching wire 1 is memorized to have an inner diameter smaller than the combined outer diameter of the overhead wire 2 and cable 3, so that the overhead wire 2 and cable 3 are tightened. Therefore, the cable 3 is prevented from becoming slack and does not vibrate independently even when a strong wind blows, and damage and fatigue of the cable 3 can be prevented.

In this case, if the lashing wire 1 is simply stretched in a straight line after being memorized,
Although the twist is added, overhead line 2 and cable 3
By adding 100% twist to the outer periphery of the wire, it is possible to wrap the wire in approximately the same shape as the memorized spiral shape, but in the unlikely event that the inner surface of the memorized spiral shape is slightly shifted and the overhead wire Even if it is wrapped around the cable 2 and the cable 3, there is no problem because it will twist itself and return to the memorized state when returning to the memorized state by heating.

When it is desired to wrap the lashing wire 1 so that the inner surface of the helical shape whose shape has been memorized surely faces inward, for example, the cross-sectional shape of the lashing wire 1 may be made oval as shown in FIG. Alternatively, as shown in FIG. 5, it may be made into a non-circular shape such as a semi-cylindrical shape so that the surface to be wrapped can be clearly identified. In this case, lashing wire 1
When the material is memorized and then stretched into a straight line, if the material is simply stretched and twisted before being wound onto a drum, etc., the material should be twisted 100% during winding so that the inside surface faces inward. do. In addition, when the lashing wire 1 is made to memorize its shape and then stretched into a straight line, if the lashing wire 1 is wound onto a drum or the like while being untwisted to avoid twisting, the lashing wire 1 is wound without untwisting so that it becomes inside. Make sure the right side faces inward.

The heating temperature for restoring the memorized state is preferably higher than the temperature expected before installation, and for example, the transformation point is set at 70°C to 100°C. The heating method is to heat the lashing wire itself by applying electricity, or to heat it with a heater or the like.

When heating with electricity, an insulating layer 4 is formed on the surface of the lashing wire 1 as shown in FIGS. 6 to 8.
It is preferable to provide a switch so that the current does not flow elsewhere.

As explained above, since the lashing wire according to the present invention is made by straightening a shape memory alloy wire whose shape has been memorized in a spiral shape, winding can be easily performed using a lashing machine or the like. In addition, by heating to restore the memorized state, it is possible to apply a tightening force to the object to be wrapped after wrapping, and even if the object is cut, it will not unravel from the object to be wrapped, and the A state of unity can be maintained.

Next, a cable installation method using a lashing wire according to the present invention uses a lashing wire made of a straight shape memory alloy wire whose shape has been memorized in a spiral shape, and is attached to an overhead wire. Since it is wrapped around the outer periphery of the cable, it can be easily wrapped. In addition, since the wire is heated after winding to return it to the spiral memorized state, the overhead wire and cable can be tightened after winding, which can compensate for the drawbacks of using a lashing machine or the like.

[Brief explanation of drawings]

FIG. 1 is a side view of the lashing wire according to the present invention, FIGS. 2 and 3 are cross-sectional views and side views of the overhead wire and cable around which the lashing wire is wound by the method of the present invention, and FIG. Figures 8 through 8 are cross-sectional views of five other examples of the lashing wire according to the present invention. 1... Lashing wire, 2... Overhead wire, 3... Cable.

Claims (1)

[Claims] 1. A lashing wire made by straightening a shape memory alloy wire whose shape has been memorized in a spiral shape. 2. The lashing wire according to claim 1, wherein the inner diameter of the spiral shape memorized in the shape memory alloy wire is approximately 60% to 90% of the outer diameter of the object to be wrapped. 3. The lashing wire according to claim 1 or 2, wherein the shape memory alloy wire has an insulating layer on its surface. 4 A spiral pitch in which a cable is attached to an installed overhead line, and a lashing wire made of a straight shape memory alloy wire whose shape is memorized in a spiral is memorized around the outer periphery of the overhead line and the cable. Cable installation using a lashing wire, characterized in that the lashing wire is wound spirally at approximately the same pitch as the lashing wire, and then the lashing wire is heated to return to the spiral memorized state and the overhead wire and the cable are tightened. Method.