JP3445489B2 - Bypass cable with detection function - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a bypass cable used in an uninterruptible bypass construction method for overhead distribution lines, and more particularly to a bypass with a detection function capable of detecting a break in a shielded braid layer of the bypass cable. It is about cables.

[0002]

2. Description of the Related Art A bypass cable is provided with a shield layer on an outer semiconductive layer from the viewpoint of security and cable performance. Usually this shielding layer has a diameter of 0.12 mm
It has a braided structure in which a thin copper wire (metal element wire) of about 0.20 mm is woven, and is configured to withstand external forces such as repeated bending, tension, and twisting applied to the cable during use. For example, as shown in FIG. 9, a plurality of thin copper wires 2
In many cases, a combined weave braid in which the aggregate 22 and the cotton yarn 23 are bundled into one unit, the aggregate 22 is arranged in one direction, and the cotton yarn 23 is woven in a direction intersecting with the aggregate 22 is adopted.

When all the metal wires 21 of the shielding layer are broken,
The area far from the disconnection point is not grounded and is very dangerous. Therefore, it is desirable to detect this when some of the metal element wires 21 are broken.

However, the bypass cable having the conventional structure has a problem in that the disconnection of the metal wire 21 in the shielding layer cannot be effectively detected.

[0005]

Therefore, the present applicants proposed a bypass cable as shown in FIGS. 7 and 8 (Japanese Patent Application No. 9-152905). Briefly, this bypass cable is connected to the core 2 as shown.
Has a shielding layer 3 on it, and a sheath 4 on it. The core 2 is composed of a conductor 5, an inner semiconductive layer 6, an insulator layer 7, and an outer semiconductive layer 8 in order from the center.

Further, the shield braided layer 3 has a metal portion 9 and a detection wire 1.
0 and the non-metal portion 11, for example, the metal portion 9 is a tin-plated annealed copper wire, the detection wire 10 is an enamel wire, and the non-metal portion 11 is a braid structure made of cotton yarn.

A plurality of tin-plated annealed copper wires 9 to be metal element wires and at least one enamel wire 10 are bundled together to form an assembly 12.
Is formed, the aggregate 12 is arranged, the cotton yarn 11 is arranged on the other side, and the both 11 and 12 are woven to form a mixed woven braid. In the shielding braid layer 3, the enameled wire 10 of “the number of enameled wires combined in one assembly × the number of assembled bodies”
Will be woven. The total cross-sectional area of the metal element wire 9 is selected to be a value necessary for flowing the current induced in the cable shielding layer 3 to the ground.

When the cable receives an external force and the breakage of the metal element wire 9 in the shield braid layer 3 progresses, the enamel wire 10 also breaks. Since the enamel wire 10 has an insulating coating, even if the enamel wire 10 is broken, a conductive path is not formed via the adjacent metal element wire 9. Therefore, each enameled wire 10
If the continuity check is performed, the disconnection of the metal element wire 9 can be surely detected.

The present invention relates to a further improved concrete structure of the bypass cable having such a structure.

That is, an object of the present invention is to provide a bypass cable with a detection function having a terminal structure capable of easily detecting a disconnection of a metal wire of a shielding braid layer of the bypass cable even when the disconnection partially occurs. Is to provide.

[0011]

The above object can be achieved by a bypass cable with a detecting function according to the present invention. In summary, the present invention is a bypass cable comprising a shielded braided layer having a metal portion, a detection wire and a non-metal portion as a braided structure , wherein the terminal portion detects conduction of the detection wire,
A bypass cable that determines the deterioration of the shielding braid layer .
And the metal part of the shield braid and the sensing line are
One end of the I-pass cable is electrically connected,
At the other end of the bypass cable, a plurality of
Has an electrode that is insulated from the
Detection connector and protective metal fittings are provided, and at least
Some of the sensing wires are electrically connected to the sensing connector.
The remaining detection wires and metal parts are
It is a bypass cable with a detection function that is electrically connected .

[0012]

[0013] Preferably, at least one of the terminal portion of the bypass cable semiconductive portion, the insulating portion and the protective fitting is a wall outlet terminal having a terminal mold portion which is integrally molded, the sensing connector, the outlet attached to said metallic protecting cylinder which is attached to the protective bracket of the terminal, also the connected to the detection connector the remaining detection line and the metal portions are electrically connected to the protective bracket.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION A bypass cable with a detecting function according to the present invention will be described below in more detail with reference to the drawings.

The bypass cable of the present invention has the same structure as the bypass cable 1 described above with reference to FIGS. 7 and 8. That is, the shielding braid layer 3 and the sheath 4 are arranged on the core 2. The core 2 is composed of a conductor 5, an inner semiconductive layer 6, an insulator layer 7, and an outer semiconductive layer 8 in order from the center, and the shield braided layer 3 is composed of a metal portion 9, a sensing wire 10 and a non-metal portion 11. Composed.

Further, the shielded braided layer 3 of the bypass cable 1
In this embodiment, as described above, the metal portion 9 is a metal element wire such as a tin-plated annealed copper wire, the detection wire 10 is an enamel wire, and the non-metal portion 11 is a cotton braid structure. To be done. A plurality of tin-plated annealed copper wires 9 to be metal element wires and at least one enamel wire 10 are bundled to form an aggregate 12, the aggregate 12 is arranged, and a cotton thread 11 is arranged on the other side to form both 11, 12 is woven to form a interwoven braid. As the metal element wire, in addition to the tin-plated annealed copper wire, another thin copper wire having a small diameter can be used. Further, as the non-metal portion 11, in addition to natural fibers such as cotton yarn, synthetic fibers such as polyamide resin may be used.

Thus, the bypass cable 1 of the present invention
Is provided with a shield braid layer 3 having a braid structure in which an assembly 12 of metal wires 9 is woven, and each assembly 12 is combined with at least one detection wire 10 having an insulating coating.

According to the present invention, the disconnection detection of the shield layer braided layer 3 is performed by the continuity check of the disconnection detection line 10.
If the detection line 10 is a conductor with an insulating coating,
In particular, the material and structure may be arbitrary. The detection line 10 may be any line that does not form a conduction path via the adjacent metal element wire 9 when the detection line 10 is broken. For example, as described above, an enameled wire or the like is preferable. In particular, JIS
A standard product such as 3202 can be preferably used. Further, the method of combining the detection wire 10 and the metal element wire 9 is not particularly limited.
It can be bundled together with the metal element wires 9 or twisted together.

The outer diameter of the detection wire 10 is selected to be an optimum value so as to disconnect the metal wire 9 at the same time or earlier. When the outer diameter of the detection wire 10 is d and the outer diameter of the metal element wire 9 is D,
It is preferable that d / D is 0.5 to 2.0. The breakage of the shield braided layer 3 due to an external force during the use of the cable is due to both ductile fracture and fatigue fracture.
The smaller the value of d for ductile fracture and the larger d for fatigue fracture, the easier the disconnection. Under use conditions where ductile fracture is dominant, d / D is preferably 0.5 or more, and under use conditions where fatigue fracture is dominant, d / D is preferably 2.0 or less.

Further, on the shielding braid layer 3, the restraining tape 1
3, an inner sheath 14, a reinforcing layer (Kevlar) 15, and an outer sheath 16 are arranged.

Table 1 shows a more detailed structure of the bypass cable 1 used in this embodiment.

[0022]

[Table 1]

Next, an embodiment of the measuring side terminal structure of the bypass cable with a detecting function according to the present invention will be described.

FIG. 1 shows the structure 1A of the measuring side terminal of the bypass cable 1. The terminal portion of the cable to be connected is subjected to a terminal treatment for the connection work, and the conductor portion 5 and the inner semiconductive layer-containing insulator (cross-linked polyethylene) are sequentially provided from the most distal conductor portion 5 to the outer sheath 4. The layer 7, outer semiconductive layer 8, shield braid layer 3, etc. are exposed.

A conductor connecting terminal 31 is connected to the conductor portion 5 of the cable thus terminated. On the conductor connection terminal 31 and the outer circumference of the cable subjected to the terminal treatment, the terminal mold portion 30 is integrally formed by molding the semiconductive portion (EP rubber) 32, the insulating portion (EP rubber) 33, and the protective metal fitting 34.

To further explain, in the present embodiment, the semiconductive portion 32 is arranged in the inner and outer peripheral areas of the conductor connection terminal 31 compression-connected to the cable conductor portion 5. The semiconductive portion 32 and the insulating portion 33 integrally molded with the outer peripheral portion of the cable subjected to the terminal treatment include an inclined portion 33A extending from the semiconductive portion 32 to the outer peripheral portion of the cable, and an outward portion from the semiconductive portion 32. In this embodiment, the cylindrical portion 33B extending to the left side is provided. Therefore, the outer periphery of the conductor connection terminal 31 and the insulating layer 3
An annular space for a connected terminal (not shown) to which the bypass bus terminal is connected is formed between the outer and inner peripheral portions of 3.

The protective metal fitting 34 is the cylindrical portion 3 of the insulating portion 33.
It is integrally molded on the outer circumference of 3B. The outer peripheral portion of the protective fitting 34 has a large diameter portion 34A, a medium diameter portion 34B and a small diameter portion 34C.
Is stepped. The mounting portion 41 of the connection nut 40 is rotatably attached to the middle diameter portion 34B of the protective fitting 34 on the side adjacent to the large diameter portion 34A. In this mounting part 41,
A ball plunger 42 is arranged. Also, the connection nut 4
The other outer end of 0 extends further outward than the large diameter portion 34A of the protective fitting 34, and a thread groove 43 is formed on the inner peripheral portion thereof. At the time of non-measurement, a protective cap 45 is screwed onto the thread groove 43 as shown in FIG. Protective fitting 3
On the other side of the medium-diameter portion 34B of No. 4, one end of a protection cylinder 50, which is substantially cylindrical in this embodiment and is made of aluminum, is fixed with a countersunk screw 51.

The other end of the protective cylinder 50 is provided with the inclined portion 3 of the insulating portion 33.
3A, a recess 52 is formed adjacent to the end of the recess 52, and the detection connector 53 having a plurality of terminals (electrodes) insulated from each other is mounted in the recess 52.
Further, in the recess 52, a detection connector cap 54 made of metal, for example, a copper alloy, is detachably screwed onto the detection connector 53. The cap 54 has a function of electrically connecting all the detection connector electrodes by being mounted on the detection connector 53.

The aggregate 12 composed of the metal portion 9 and the detection wire 10 constituting the shield braided layer 3 exposed by the cable end treatment, together with the cotton thread 11 and the like, if necessary, the insulating portion 3
It is wound around the outer periphery of the inclined portion 33A of No. 3. Then
In this embodiment, six detection lines 10 are selected every other stroke from among the 12 detection lines 10 as the monitor detection lines 10.
The detection wire 10 is soldered to the lead wire 55 from each electrode of the detection connector 53, and then the heat shrinkable tube 56 is attached to this portion.

As can be seen from Table 1, the number of the detection lines 10 entering the bypass cable 1 is 12 in this embodiment, one for each striking in order to improve the balance during braiding. With the structure. However, considering the site inspection work, the size, and the reliability of the detection function, it has been found that the appropriate number of the detection lines 10 to be monitored is six.

The life of the bypass cable is determined by the detection line 12
It was found from the experimental result that three of the books were broken. Therefore, in this embodiment, the monitor detection line 10 is set to 12
Since there are six wires in every other wire, it is preferable from the safety point of view that the life of the cable is the time when one of the detection wires 10 is broken.

According to the present embodiment, a thread groove is formed on the outer periphery of the small diameter portion 34C of the protective metal fitting 34, and the step ring 60 shown in FIG. 2 is screwed. A plurality of flat braided conductors 61 are attached to the stepped ring 60 by soldering, and the flat braided conductors 61 are provided with metal portions 9 from the shielding braid layer 3 and exposed from the end treatment of the cable. , The remaining detection line 1 connected to the detection connector 53
0s are connected together.

One end of the protective cylinder mold 70 is integrally provided at the end of the protective cylinder 50, and the other end of the protective cylinder mold 70 is fitted into the cable jacket 4. Cerbon tape 71 is provided at the connecting portion between the end of the protective cylinder mold and the cable jacket.
And the adhesive vinyl tape 72 is wound.

FIG. 3 shows an embodiment of the non-measurement side terminal structure 1B of the bypass cable 1 with a detection function according to the present invention.

According to this embodiment, the non-measurement-side terminal structure 1B of the bypass cable shown in FIG. 3 is similar to the above-mentioned measurement-side terminal structure 1A, and members having the same configuration and function are designated by the same reference numerals. Description is omitted, and only different configurations and members will be described.

According to this embodiment, the protective connector 50 is not provided with the detection connector 53 in the non-measurement terminal 1B. In addition, the assembly 12 including the metal portion 9 and the detection wire 10 which constitute the shield braid layer 3 exposed by the cable end treatment is wound around the outer periphery of the inclined portion of the insulating portion 33 together with the cotton thread 11 if necessary. , Is directly connected to the end of the protective fitting 34 by soldering or the like.

Next, a detecting method in the bypass cable 1 with a detecting function of the present invention having the above-mentioned structure will be described.

The life of the bypass cable 1 of the present invention is detected on the side where the detection connector 53 is provided, that is, the terminal section 1A shown in FIG. 1, that is, the outlet terminal. The other end,
That is, in the outlet terminal 1B shown in FIG. 3 in which the detection connector 53 is not provided, as described above, the detection wire 10 and the tin-plated annealed copper wire 9 that is the metal portion are connected via the connection fitting 34.

4 and 5 schematically show the electrical connection mode of the measuring side terminal 1A and the non-measuring side terminal 1B during measurement and non-measurement.

That is, in detecting the life of the shield braid layer 3 in the bypass cable 1 of the present invention, the detection cap 54 of the outlet terminal 1A is removed as shown in FIG.
The measurement lead wire 80 is attached to the detection connector 53.
The protective fitting 34 is grounded.

Then, as shown in FIG.
Each wire core is sequentially connected to the protective fitting 34, and the continuity between each electrode of the detection connector 53 of the outlet terminal and the protective fitting 34 is confirmed. If there is no continuity between the detection connector electrode and the protective metal fitting, in FIG. 6, the judgment lamp 82 at a predetermined location of the measuring instrument 81 is turned off to turn off the shield braid layer 3 connected to the detection connector 53. It shows that the detection line (enamel line) 10 is broken.

At the time of non-measurement, that is, when the bypass cable is used, the detection connector 53 is covered with the metal detection connector cap 54 so that the detection lines 10 connected to the detection connector 53 are connected to each other. Since the detection connector cap 54 is electrically connected to the metal protective cylinder 50, each detection line 10 is eventually connected to the metal portion 9 at both end portions 1A and 1B as shown in FIG. The Rukoto.

According to the present invention, since the increase in the number of breaks in the tin-plated annealed copper wire 9 and the increase in the breakage number in the enamel wire 10 substantially follow each other, the life of the cable is determined based on the predetermined number of breaks in the enamel wire 10. You can judge.

That is, according to the present invention, it is possible to detect the disconnection that has occurred in the shielding braid layer 3 before all the metal element wires 9 reach the disconnection. That is, when disconnection occurs in the aggregate unit, only the enamel wire 10 as a detection line that is combined with the aggregate is disconnected, and the enamel wire 10 of another aggregate is disconnected.
Since there is no disconnection, it is possible to grasp the disconnection that has occurred in the shield braid layer 3 when the disconnection of the metal element wire 9 has partially occurred.

If the wire breakage detection wire 10 is made of a material and an outer diameter that breaks faster than the metal wire 9, and if the wire breakage of the detection wire 10 is detected, the wire breakage of the metal wire 9 will occur in the near future. Can be expected.

In the above embodiment, the measuring side outlet terminal 1
Although the detection connector 53 arranged in A is a 6P connector, it is not limited to this and various detection terminals can be used. Further, although the non-measurement side terminal is described as an outlet terminal as shown in FIG. 3, the bypass cable of the present invention is not limited to this, and the operation rod mounting terminal well known to those skilled in the art. Alternatively, it may be a PC insertion tool attachment terminal. Also in this case, the metal portion 9 and the detection wire 10 which form the shield braided layer 3 exposed by the cable end treatment,
Take sufficient offset and connect to the mounting hardware.

[0047]

As described above, the bypass cable with a detection function according to the present invention is a bypass cable including a shield braid layer having a metal portion, a detection wire and a non-metal portion as a braid structure, and a terminal portion. A bypass cable that detects the continuity of the detection line and determines the deterioration of the shielding braid layer
, The metal part of the shielding braid layer and the detection line are
One end of the cable is electrically connected and
At the other end of the pass cable, isolate a number of
Each of the detection connectors has an electrode to which a detection wire is connected.
Sensor and protective metal fittings, and at least a part of the detection wire
Is electrically connected to the detection connector, and the remaining detection line and
Since the metal portion is configured to be electrically connected through the protective metal fitting, the disconnection can be easily detected even when the disconnection of the metal element wire of the shield braid layer of the bypass cable partially occurs.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a structure of a measurement side terminal of a bypass cable with a detection function according to the present invention.

FIG. 2 is a perspective view of a step ring.

FIG. 3 is a partial cross-sectional view showing an embodiment of the structure of the non-measurement side terminal of the bypass cable with a detection function according to the present invention.

FIG. 4 is a diagram illustrating an electrical connection mode of a measurement-side terminal and a non-measurement-side terminal during measurement.

FIG. 5 is a diagram illustrating an electrical connection mode of the measurement side terminal and the non-measurement side terminal during non-measurement.

FIG. 6 is a diagram illustrating a method for detecting and measuring the life of a bypass cable.

FIG. 7 is a perspective view showing an embodiment of a bypass cable that can be used in the present invention.

FIG. 8 is a sectional view showing an embodiment of a bypass cable that can be used in the present invention.

FIG. 9 is a perspective view showing a shielding layer of a conventional bypass cable.

[Explanation of symbols]

1 bypass cable 3 Shielding braid layer 9 Metal part (metal wire) 10 detection lines 11 Non-metal part (cotton thread) 30 Terminal mold 34 Protective fitting 53 Detection connector 54 Detection Connector Cap

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Toyama               2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa               No. 1 Showa Electric Cable Co., Ltd.                (56) Reference JP-A-10-326526 (JP, A)

Claims (2)

(57) [Claims] 1. A bypass cable comprising a shield braid layer having a metal portion, a detection wire and a non-metal portion as a braided structure , wherein continuity of the detection wire is detected at a terminal portion of the shield braid layer. Bypass cable odor for judging deterioration
Te, metal parts and the sensing line of the shielding braid layer, said bypass
One end of the cable is electrically connected and
At the other end of the ipass cable, insulate multiple
Detection electrodes having electrodes connected to the detection lines.
An intelligent connector and protective metal fittings are provided, and at least some
The detection wire is electrically connected to the detection connector and
The detection wire and metal part of the
Bypass cable with detection function, which is connected to the . Wherein at least one of the terminal portion of the bypass cable semiconductive portion, the insulating portion and the protective fitting is a wall outlet terminal having a terminal mold portion which is integrally molded, the sensing connector, the outlet terminal In front of
The remaining detection line and the metal portion attached to the metal protective cylinder attached to the protective fitting and connected to the detection connector are electrically connected to the protective fitting. Bypass cable with detection function of 1 .