JP2006278110A - Bind for winding around electric wire and method for detecting damaged area of electric wire using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To hold an electric wire on an insulator with a bind for winding around electric wire, where the bind for winding around electric wire is made of a shape memory alloy, and to provide a method which easily detects a damaged area of the electric wire by inspection-viewing a deformation of the bind for winding around electric wire from the ground, where the bind for winding around electric wire is deformed into a memorized shape when a temperature of the bind for winding around electric wire is raised by a tracking phenomenon occurring between the electric wire and an end of the bind for winding around electric wire and becomes a predetermined value or more. <P>SOLUTION: A leakage current flows and concentrates at an end portion 13 of a bind for winding around electric wire 1 to generate a Joule's heat. When the Joule's heat decomposes a part of an insulator of a coating of a wire 11 and the tracking phenomenon causing a local discharge at a temperature of several thousand degree occurs, a temperature of an end portion 13 of the bind for winding around electric wire 1 is raised. If the temperature becomes the predetermined value or more, the end portion 13 of the bind for winding around electric wire 1 is deformed into a direction apart from the wire 11. This allows the deformation to be detected by inspection-viewing from the ground and the damaged area of the electric wire 11 to be found out easily. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric wire winding binding for holding an electric wire on an insulator and a method for detecting a damaged portion of the electric wire using the electric wire winding binding.

For example, as shown in Patent Document 1, a conventional wire winding bind is insulatively coated with a metal wire having elasticity and high tension, and a semicircle so that a central portion in a longitudinal direction is wound around a neck portion of an insulator. It is bent and formed in an arc shape, and its both side portions are bent and formed in a spiral shape so as to be wound around the electric wire. And an electric wire is arrange | positioned at the neck part of a lever, the semicircular arc center part of a wire winding binding is hung on the neck part of a lever, and an electric wire is hold | maintained at a lever by winding both ends of a spiral shape around an electric wire. . The electric wire is gripped by the spiral side portions of the wire winding bind by the elastic force of the metal wire.
JP 2003-281904 A

  However, in the wire winding binding that has been used in the past, the end of the winding binding that is wound so as to grip the wire gradually because the wire and the wire winding binding are repeatedly subjected to vibration by wind or the like. There is a possibility that the wire binds to the electric wire, and the covering of the winding binding end and the coating of the electric wire are damaged to expose each other. If the metal part of the wire is exposed, a ground fault may occur. However, since the damage range of the coating is narrow, there is a problem that it is difficult to find by visual inspection from the ground by normal patrol. .

  Therefore, the present invention has been made in view of the above-described problems, and the object thereof is to hold an electric wire on an insulator by an electric wire winding binding made of a shape memory alloy, and to end the electric wire and the electric wire winding binding. When the temperature of the wire winding bind exceeds the predetermined value due to the tracking phenomenon that occurs between the wire and the wire, the wire winding bind is deformed into the shape stored, and this deformation is detected by visual inspection from the ground. A method for easily detecting a damaged portion of an electric wire is provided.

  The wire winding bind of the present invention that solves the above problem is a helical wire winding bind that is attached across the wire and the insulator so as to hold the wire on the insulator, and at least one end portion thereof has a predetermined temperature. It is characterized by comprising a shape memory alloy having a shape spaced apart from the electric wire as described above (first invention).

  A second invention is characterized in that, in the first invention, the end portion of the wire winding bind is colored in a color different from that of other parts.

  According to a third aspect of the present invention, there is provided a method for detecting a damaged portion of an insulation coating of an electric wire in a method of detecting a damaged portion of the insulation coating of the electric wire in a portion where the electric wire is held by an insulator by the electric wire winding binding. At least one end is made of a shape memory alloy that is separated from the electric wire when the temperature exceeds a predetermined temperature, and the electric wire is caused by a current flowing from the electric wire to the electric wire winding bind when the insulation coating is damaged. The temperature of the winding bind is raised, and it is detected that the at least one end portion is deformed due to the temperature rise causing the wire winding bind to become the predetermined temperature or higher.

  According to the wire winding bind according to the present invention, the temperature of the wire winding bind rises due to the tracking phenomenon that occurs between the electric wire and the end of the wire winding bind, and at least the wire winding bind when the temperature exceeds a predetermined temperature. Since one of the end portions is deformed in a direction away from the electric wire, the deformation can be detected by visual inspection from the ground, and the damaged portion of the electric wire can be easily detected. In addition, it is possible to easily detect the deformation of the winding binding by coloring the deformed portion of the wire winding binding with a color different from that of other portions.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  Drawing 1 is a figure showing the state where an electric wire was held at an insulator using electric wire winding binding concerning an embodiment of the present invention. The wire winding bind 1 includes a rod-shaped shape memory alloy made of a nickel-titanium alloy and a nylon resin coating that coats the shape memory alloy with an insulator, and has elasticity and high tension. Further, the shape of the wire winding bind 1 is formed in a semicircular arc shape so that the central portion 3 in the longitudinal direction is wound around the neck portion 7 of the insulator 5, and both side portions 9 are spirally wound around the wire 11. The both ends 13 are formed so as to be separated from the electric wire 11 when the temperature is higher than a predetermined temperature. In addition, as a shape memory alloy constituting the electric wire winding bind 1, a shape memory alloy having a property of maintaining the shape even when the temperature is lowered after the deformation is deformed into a memorized shape when the temperature is higher than a predetermined temperature. Shall be used.

  And as shown in FIG. 1, the electric wire 11 is arrange | positioned to the neck part 7 of the insulator 5, the semicircular arc-shaped center part 3 of the electric wire winding bind 1 is hung on the neck part 7 of the insulator 5, and the spiral both sides 9 Is wound around the electric wire 11, and both ends 13 facing away from the electric wire 11 are spirally deformed with a tool such as pliers and wound so as to bite into the coated surface of the electric wire 11. Retained. The electric wire 11 is held by the spiral side portions 9 and both end portions 13 of the wire winding bind 1 by the elastic force of the shape memory alloy.

  In this embodiment, the nickel-titanium alloy is used as the material of the shape memory alloy, but the material is not limited to this, and other alloys such as a copper-zinc-aluminum alloy may be used.

  Drawing 2 is a mimetic diagram showing the state where the electric wire winding binding concerning the embodiment of the present invention changed. When dust or the like adheres to the coating surface of the electric wire 11 and absorbs moisture in the atmosphere, the coating surface of the electric wire 11 becomes wet, and leakage current due to a decrease in insulation resistance increases. Here, since the end portion 13 of the winding bind 1 wound spirally so as to hold the electric wire 11 is wound around the electric wire 11, the end portion 13 of the electric wire winding bind 1 is wound around the end portion 13 of the electric wire winding bind 1. Leakage current flows intensively and Joule heat is generated. When a part of the insulation of the covering of the electric wire 11 is decomposed by the Joule heat and a tracking phenomenon occurs that causes a local discharge of about several thousand degrees between the electric wire 11 and the end portion 13 of the electric wire winding bind 1, the electric wire winding is performed. When the temperature of the end portion 13 of the binding bind rises and the temperature becomes a predetermined value or more, the end portion 13 of the wire winding bind 1 is deformed in a direction away from the wire 11, that is, a memorized shape. In this embodiment, the predetermined temperature at which the wire winding bind 1 is deformed is, for example, about 215 to 265 ° C., which is the melting point temperature of the nylon resin coating. Note that the temperature at which the wire winding bind 1 is deformed can be changed as appropriate depending on the voltage of the wire 11, the ambient environmental temperature, and the like.

  As described above, the end portion 13 of the wire winding bind 1 deformed in the direction away from the electric wire 11 does not return to the shape of the state wound around the electric wire 11 even when the temperature is lower than a predetermined temperature. Therefore, the damaged part of the electric wire 11 can be detected visually from the ground by patrol as a normal inspection. Further, by coloring the deformed portion into a conspicuous color such as red or yellow different from other portions, the deformation can be easily detected visually.

  As described above, the temperature of the wire winding bind rises due to the tracking phenomenon that occurs between the electric wire and the end of the wire winding bind, and at least one end of the wire winding bind 1 when the temperature exceeds a predetermined temperature. Since 13 is deformed in the direction away from the electric wire 11, this deformation can be detected by visual inspection from the ground, and the damaged portion of the electric wire 11 can be easily detected.

  In the present embodiment, the inside of the wire winding bind 1 is made of a shape memory alloy. However, the present invention is not limited to this, and only both ends 13 or one end of the wire winding bind 1 are made of a shape memory alloy. The central part 3 and both side parts 9 may use metal wires that are generally used.

It is a figure which shows the state which hold | maintained the electric wire to the insulator using the electric wire winding binding which concerns on embodiment of this invention. It is a schematic diagram which shows the state which the electric wire winding binding which concerns on embodiment of this invention deform | transformed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire winding bind 3 Center part 5 Insulator 7 Neck part 9 Both sides 11 Electric wire 13 End

Claims (3)

A helical wire winding bind attached across the wire and the insulator to hold the wire to the insulator,
An electric wire winding bind characterized in that at least one end portion is made of a shape memory alloy having a shape separated from the electric wire when a predetermined temperature or higher is reached.   The wire winding bind according to claim 1, wherein an end portion of the wire winding bind is colored in a color different from other portions. In the method of detecting a damaged portion of the insulation coating of the electric wire in a portion where the electric wire is held by the insulator by the electric wire winding binding,
At least one end of the wire winding bind is configured with a shape memory alloy that becomes a shape separated from the wire when a predetermined temperature or higher is reached,
Increasing the temperature of the wire winding bind by the current flowing from the wire to the wire winding bind when the insulation coating is damaged,
A method for detecting a damaged portion of an insulating coating of an electric wire, comprising detecting that the electric wire winding bind is heated to the predetermined temperature or more due to the temperature rise and the at least one end portion is deformed.

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