JP2007042412A - Cable with warning wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To promptly and surely detect infiltration of water even if water infiltrates in a cable due to external flaw of the cable. <P>SOLUTION: A first pressing and winding tape 6 is wound on a wire core formed by twisting a plurality of insulated wire cores 4. A second pressing and winding tape 7 is wound on the first pressing and winding tape 6. The warning wire 8 is laid along a longitudinal direction between the first pressing and winding tape 6 and the second pressing and winding tape 7. A sheath 9 is covered on the second pressing and winding tape 7. Thus the cable with the warning wire is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cable with an alarm line, and more particularly, to a cable with an alarm line that can quickly and surely detect the intrusion of water even if the cable is damaged and water enters the inside of the cable.

  When cables installed outside are damaged in the sheath of the cable, water penetrates into the inside of the cable, and the infiltrated water degrades the insulation of the insulation core, causing a short circuit between the insulation cores. May occur. If the phenomenon of water intrusion into the inside of the cable is detected by the occurrence of a short circuit between the insulated core wires, this phenomenon is not detected at an early stage, and the response to this phenomenon may be delayed. . For this reason, there has been a demand for a cable that can quickly detect the intruded water when the cable is damaged and water enters the inside of the cable. Therefore, a cable with an alarm line having an alarm line inside the cable has been used as a cable that can quickly detect water that has entered the cable (for example, see Patent Document 1). A conventional cable with an alarm line described in Patent Document 1 is shown in a perspective view in FIG. In FIG. 6, an alarm line that can quickly detect water that has entered the inside of the cable is formed along the outermost layer of the cable core. 7 and 8 are sectional views for explaining the structure of the cable with alarm line shown in FIG.

In FIG. 7, a cable 101 with an alarm line is formed into a round shape by interposing an intermediary 105 on a stranded wire formed by twisting a plurality of insulating wire cores 104 formed by covering an insulator 103 on a conductor 102. The alarm wire 106 is twisted along the twisted wire of the interposition 105, the presser winding tape 107 is wound thereon, and the sheath 108 is extruded and coated on the presser winding tape 107.
JP-A-6-187840

  However, in the conventional cable with alarm line 101 shown in FIGS. 6 and 7, as shown in FIG. 8, the cable is damaged (C portion in the figure). In the case where water penetrates into the inside, the water that has entered easily accumulates in the concave portion (D portion in the figure) of the interposition 105 formed along the stranded wire of the insulating core 104. The water accumulated in the concave portion (D portion in the figure) of the interposition 105 is likely to be transmitted in the longitudinal direction of the cable along the concave portion of the interposition 105, but is difficult to be transmitted in the circumferential direction of the cable. Therefore, if the place where the cable is damaged (C portion in the figure) is located away from the alarm line 106 provided inside the cable 101 with the alarm line, it will enter the inside of the cable. Since the water accumulated in the concave portion (D portion in the figure) of the interposition 105 is difficult to be transmitted in the circumferential direction of the cable, it takes time for the infiltrated water to reach the alarm line 106. As a result, the conventional cable 101 with an alarm line has a problem that the water that has entered the cable cannot be detected quickly and reliably by the alarm line 106.

  In particular, in the case of a cable with an alarm line having a large number of cores, water that has entered the cable is more likely to collect in the recesses of the interposition 105, so that it is difficult to be transmitted to the alarm line 106. There is a problem that the information cannot be detected promptly and reliably by 106.

  An object of the present invention is to provide a cable with an alarm line that can quickly and surely detect the entry of water even if the cable is damaged and water is immersed in the cable.

  The cable with an alarm line according to the first aspect of the present invention includes a first press-winding tape wound on a wire core obtained by twisting a plurality of insulated wire cores, and a top of the first press-winding tape. A second presser wound tape wound around the first presser wound tape, a warning line vertically attached between the first presser wound tape and the second presser wound tape, and a coating on the second presser wound tape. It is characterized by comprising a sheath which is made.

  According to the first aspect of the present invention, even if the cable is damaged and water is submerged in the cable, the gap between the first presser winding tape and the second presser winding tape is overlapped. Since the infiltrated water can easily infiltrate in the circumferential direction of the cable by capillary action, it can reach the alarm line in a short time and is detected quickly and reliably by the alarm line. Even if the cable has a large number of wire cores, the water that has entered the inside of the cable can be removed by the capillary action in the gap formed by the overlap of the first presser tape and the second presser tape. Since it can easily penetrate in the circumferential direction, the alarm line can be reached in a short time, and is detected quickly and reliably by the alarm line.

  The cable with an alarm line according to the second aspect of the present invention is configured such that the first press-winding tape and the second press-winding tape are tapes having a water supply rate of 0.5% or less (24 hours). Is.

  According to the second aspect of the present invention, the first press winding tape and the second press winding tape both use the tape that is difficult to penetrate water. In the gap formed by the overlapping of the winding tape, the water that has entered the cable can easily and surely enter the circumferential direction of the cable by capillary action, so it can reach the alarm line in a short time. Can be detected quickly and reliably. Here, the water absorption rate (24 hours) of the tape was set to 0.5% or less. If the water absorption rate (24 hours) exceeded 0.5%, the water that entered the cable penetrated the tape. Therefore, the capillary action is less likely to occur in the gap formed by overlapping the first presser winding tape and the second presser winding tape. As those having a water absorption rate (24 hours) of 0.5% or less, known polyolefin resins such as polyethylene and polypropylene, and known thermoplastic resins such as polyvinyl chloride and polyethylene terephthalate can be used.

  The cable with an alarm line according to the third aspect of the present invention is characterized in that at least one of the first press-winding tape and the second press-winding tape has a hydrophilic surface on the surface side in contact with the alarm line. It consists of the tape being processed.

  According to the invention described in claim 3, since at least one of the first press-wound tape and the second press-wound tape has a hydrophilic surface, the surface tension of the tape surface is reduced, and the capillary tube The action becomes more effective. Therefore, in the gap formed by the overlap of the first presser tape and the second presser tape, the water that has entered the cable due to damage to the cable is more easily transmitted through the surface of these tapes to alert The line can be reached in a short time and is detected quickly and reliably by the warning line.

  The cable with an alarm line according to the present invention described in claim 4 is characterized in that at least one of the first presser winding tape and the second presser winding tape has an uneven shape on the surface side in contact with the alarm line. Is formed of a tape on which is formed.

  According to the invention described in claim 4, since at least one of the first press-wound tape and the second press-wound tape has an uneven shape on the tape surface, the wettability of the tape surface is improved. In the gap formed by the overlap between the first presser tape and the second presser tape, water that has entered the cable due to damage to the cable can easily enter the circumferential direction of the cable by capillary action. Therefore, the alarm line can be reached in a short time, and the alarm line can be detected quickly and reliably.

  The cable with an alarm line according to the present invention described in claim 5 is configured such that the first press-wound tape is a tape whose thickness is thicker than that of the second press-wound tape.

According to the invention of claim 5, when the cable is damaged, even if the second presser winding tape is torn, the first presser wound tape is less likely to be broken than the second presser wound tape. Water that has entered the inside of the cable is retained between the first presser tape and the second presser tape, and in the gap formed by the overlap of the first presser tape and the second presser tape. Since it can easily penetrate in the circumferential direction of the cable by capillary action, it can reach the alarm line in a short time, and can be detected quickly and reliably by the alarm line.
The cable with an alarm line according to the present invention described in claim 6 is configured such that the first press-wound tape is a tape whose strength is greater than that of the second press-wound tape.

  According to the invention of claim 6, when the cable is damaged, even if the second presser winding tape is torn, the first presser wound tape is harder to break than the second presser wound tape. The water that has entered the inside is retained between the first presser tape and the second presser tape, and in the gap formed by overlapping the first presser tape and the second presser tape, Capillary action makes it easy to penetrate the cable in the circumferential direction, so that the alarm line can be reached in a short time, and the alarm line can be detected quickly and reliably.

  According to the first to sixth aspects of the present invention, even if the cable is damaged and water enters the inside of the cable, the intrusion of water can be detected quickly and reliably.

  The present invention provides a first presser winding tape wound on a wire core obtained by twisting a plurality of insulated wire cores, and a second presser winding tape wound on the first presser winding tape, Realized by comprising an alarm line vertically attached between the first presser winding tape and the second presser tape and a sheath coated on the second presser tape. To do.

  Hereinafter, the Example of the cable with an alarm line which concerns on this invention is described in detail.

  FIG. 1 is a perspective view showing an embodiment of a cable with an alarm line according to the present invention. FIG. 2 is a cross-sectional view showing the configuration of the cable with alarm line shown in FIG. FIG. 3 is an enlarged cross-sectional view of a part of the configuration of the cable with alarm line shown in FIG.

  In FIG. 2, the cable 1 with an alarm line is formed into a round shape by interposing an intervening 5 in a stranded wire formed by twisting a plurality of insulating wire cores 4 formed by covering an insulator 3 on a conductor 2. The first presser winding tape 6 is wound thereon, and the second presser tape 7 is wound on the first presser tape 6. An alarm line 8 is vertically provided between the first presser winding tape 6 and the second presser winding tape 7, and a sheath 9 is extruded and coated on the second presser winding tape 7.

  For the conductor 2 constituting the cable with alarm line 1 shown in FIG. 2 configured as described above, known mild copper or copper alloy suitable as a conductive material is used. For the insulating material 3 coated on the conductor 2, a known thermoplastic resin such as low density polyethylene (LDPE) or polyvinyl chloride (PVC) is used.

  For the first presser winding tape 6 that presses and winds a twisted wire in which a plurality of insulated wire cores 4 formed by covering the conductor 2 with the insulator 3 are twisted, a tape that does not easily penetrate water is used. Is preferred. Here, when a tape (for example, a nonwoven fabric tape) in which water easily penetrates is used, the water that has entered the cable penetrates the inside of the tape, so the first presser winding tape 6 and the second presser winding. This is because the capillary action of water, which will be described later, hardly occurs in the gap formed by overlapping the tapes 7, and the water that has entered the cable cannot be detected quickly and reliably by the alarm line 8.

  More specifically, the water-penetrating tape will be described in more detail. As an indicator that water is difficult to penetrate, the water absorption rate (24 hours) is preferably 0.5% or less. If the water absorption rate (24 hours) exceeds 0.5%, the water that has entered the cable penetrates into the tape, and the first presser tape 6 and the second presser tape 7 overlap. This is because the capillarity of water hardly occurs in the gap formed and water penetrates into the tape. As those having a water absorption rate (24 hours) of 0.5% or less, known polyolefin resins such as polyethylene and polypropylene, and known thermoplastic resins such as polyvinyl chloride and polyethylene terephthalate can be used.

  In addition, as the second presser winding tape 7 wound around the first presser wound tape 6, a tape in which water is not easily penetrated is used similarly to the first presser wound tape 6. For this tape that is difficult to penetrate water, a known polyolefin resin such as polyethylene and polypropylene that can satisfy a water absorption rate (24 hours) of 0.5% or less, and a known heat such as polyvinyl chloride and polyethylene terephthalate. A plastic resin can be used. The tape used for the second presser winding tape 7 does not necessarily need to use the same material as the tape used for the first presser tape 6.

An alarm line 8 is vertically provided between the first presser winding tape 6 and the second presser winding tape 7. For this alarm line 8, for example, a well-known alarm line is used in which the conductor is exposed by covering the conductor with an insulator and then cutting out part of the insulator in a bowl shape over the entire length. Yes.
Since this alarm line 8 is provided between the first presser winding tape 6 and the second presser winding tape 7, the water that has entered the cable is quickly and reliably detected by the alarm line 8. The That is, as shown in FIG. 3, even if the cable is damaged (part A in the figure) and water is immersed in the cable, the first presser tape 6 and the second presser tape 7 overlap. In the gap (B portion in the figure) formed in this way, the infiltrated water can easily enter the circumferential direction of the cable by capillary action, so that the alarm line 8 can be reached in a short time. It is detected quickly and reliably.

  A sheath 9 is extrusion coated on the second presser winding tape 7. The sheath 9 is used for protecting the cable 1 with an alarm line. The sheath 9 is made of a known thermoplastic resin such as linear low-density polyethylene (L-LDPE), high-density polyethylene (HDPE), low-density polyethylene (LDPE), or polyvinyl chloride (PVC). Known additives such as flame retardants, ultraviolet absorbers, heat stabilizers and antioxidants can be blended as necessary.

  According to the cable with alarm line of the first embodiment obtained as described above, even if the cable is damaged and water is immersed in the cable, the first presser tape 6 and the second presser tape 6 In the gap formed by overlapping the presser winding tape 7, the infiltrated water can easily enter the circumferential direction of the cable by capillary action, so that the alarm line 8 can be reached in a short time. It is detected quickly and reliably.

  Further, even if the cable has a large number of wire cores, the water that has entered the inside of the cable has a capillary action in the gap formed by overlapping the first presser winding tape and the second presser winding tape 7. Since it can easily penetrate in the circumferential direction, the alarm line 8 can be reached in a short time, and the alarm line 8 can be detected quickly and reliably.

  Next, Example 2 will be described following Example 1. The configuration of the cable 11 with an alarm line according to the second embodiment is the same except for the first press winding tape 6 and the second press winding tape 7 in the cable 1 with an alarm line according to the first embodiment. Hereinafter, in the description of the cable 11 with an alarm line according to the second embodiment, the same components as those used in the cable 1 with an alarm line according to the first embodiment are denoted by the same reference numerals, and the same reference numerals are used. The description of is omitted.

  In the cable with an alarm line according to the second embodiment, the first presser winding tape 16 and the second presser winding tape 17 that are in contact with the alarm line 8 include the first presser winding tape 6 and the second presser winding tape 17 of the first embodiment. A material selected from materials that can be used for the press-wound tape 7 is used. In addition, at least one of the first presser winding tape 16 and the second presser winding tape 17 is used that has been subjected to a hydrophilic treatment on the surface of the tape in contact with the alarm line 8. . The reason for hydrophilizing the tape surface is to reduce the surface tension of the tape surface (enhance water wettability) and to make the capillary action more effective against water that has entered the cable.

  In the hydrophilization treatment, for example, a surface active agent solution is sprayed to a predetermined thickness on at least one surface of the tape used for the first press-wound tape 16 (or the second press-wound tape 17). What is applied by spraying or coating and then drying is used. After the tape to which the surfactant is attached is dried, the surface of the tape is coated with the surfactant. The coated tape is shown in cross section in FIG. That is, the first press-wound tape 16 shown in FIG. 4 has a configuration in which the coating layer 16b is coated on the tape base 16a. As the coated surfactant, a known surfactant such as sodium dodecylbenzenesulfonate, sodium butylnaphthalenesulfonate, polyoxyethylene lauryl ether can be used. In addition, as the hydrophilic treatment method, other known methods such as corona treatment, plasma treatment, and sulfonation treatment may be used.

  According to the cable 11 with the alarm line of the second embodiment obtained as described above, at least one of the first presser winding tape 16 and the second presser winding tape 17 is subjected to hydrophilic treatment on the tape surface. Therefore, the surface tension of the tape surface is reduced, and the capillary action can be more effectively performed. Therefore, in the gap formed by overlapping the first presser winding tape 16 and the second presser winding tape 17, the cable is damaged, and the water that has entered the inside of the cable more easily makes these tape surfaces The alarm line 8 can be reached in a short time, and is detected quickly and reliably by the alarm line 8.

  Next, Example 3 will be described following Example 2. The configuration of the cable with warning line 21 according to the third embodiment is the same as that of the cable with warning line 1 according to the first embodiment except for the first presser winding tape 6 and the second presser winding tape 7. Hereinafter, in the description of the cable 21 with an alarm line according to the third embodiment, the same reference numerals are given to the same components used in the cable 1 with an alarm line according to the first embodiment, and the same reference numerals are used. The description of is omitted.

  In the cable 21 with an alarm line according to the third embodiment, the first press winding tape 26 and the second press winding tape 27 that are in contact with the alarm line 8 are provided on the first press winding tape 6 and the second press winding tape 27 of the first embodiment. A material selected from materials that can be used for the press-wound tape 7 is used. Then, at least one tape of the first presser winding tape 26 and the second presser winding tape 27 has an uneven shape on the surface of the tape in contact with the alarm line 8. FIG. 5 shows a cross-sectional view of a tape having an uneven shape formed on the tape surface. That is, the first press-wound tape 26 shown in FIG. 5 has a configuration in which an uneven layer 26b is formed on a tape base material 26a. The uneven shape is formed, for example, by embossing, and is preferably formed finely from the viewpoint of wettability of the tape surface. This is because if the uneven shape is finely formed on the tape surface, the water that has entered the cable cannot form large water droplets on the surface of the tape, so that the wettability of the tape surface is improved. This is because when the wettability of the tape surface is improved, the capillary action can be more effectively applied to the water that has entered the cable.

  According to the cable with alarm line 21 of Example 3 obtained as described above, at least one of the first presser winding tape 26 and the second presser winding tape 27 has an uneven shape on the tape surface. Therefore, the wettability of the tape surface is improved, and the capillary action can work more effectively. For this reason, in the gap formed by overlapping the first presser winding tape 26 and the second presser winding tape 27, the cable is damaged, and the water that has entered the inside of the cable more easily makes the surface of these tapes more easily. The alarm line 8 can be reached in a short time, and is detected quickly and reliably by the alarm line 8.

  Next, Example 4 will be described following Example 3. The configuration of the alarm line cable 31 according to the fourth embodiment is the same except for the first presser winding tape 6 and the second presser winding tape 7 in the alarm line cable 1 according to the first embodiment. Hereinafter, in the description of the cable 31 with an alarm line according to the fourth embodiment, the same components as those used in the cable 1 with an alarm line according to the first embodiment are denoted by the same reference numerals, and the same reference numerals are used. The description of is omitted.

  In the cable 31 with an alarm line according to the fourth embodiment, the first press-winding tape 36 and the second press-winding tape 37 that are in contact with the alarm line 8 include the first press-winding tape 6 and the second press-winding tape 6 of the first embodiment. A material selected from materials that can be used for the press-wound tape 7 is used. As the first presser winding tape 36, a tape that is harder to tear than the second presser winding tape 37 is used. If the first presser winding tape 36 is harder to tear than the second presser winding tape 37, the first presser winding tape 36 will not be torn even if the second presser winding tape 37 is torn when the cable is damaged. For this reason, the water that has entered the cable can be retained between the first presser winding tape 6 and the second presser winding tape 7.

  In the cable 31 with alarm line according to the fourth embodiment, the first presser winding tape 36 is less likely to be broken than the second presser winding tape 37 so that the first presser winding tape 36 is the second presser winding tape 37. A thicker tape is used. The thickness of the first presser winding tape 36 is preferably 1.5 to 3 times the thickness of the second presser winding tape 37. This is because if the thickness is less than 1.5 times, it is difficult for the first presser winding tape 36 to be more difficult to tear than the second presser winding tape 37. On the other hand, if the thickness exceeds three times, the first presser winding tape 36 can be more difficult to tear than the second presser winding tape 37, but the cable outer diameter becomes thicker and the workability and workability of the cable are increased. This is because there is an obstacle to this.

  According to the cable 31 with alarm line of the fourth embodiment obtained as described above, even if the cable is damaged and the second presser winding tape 37 is torn, the first presser winding tape 36 is not easily torn. . Therefore, the water that has entered the cable is retained between the first presser winding tape 36 and the second presser winding tape 37, and the first presser winding tape 36 and the second presser winding tape 37 overlap. In the gap formed in this way, it is possible to easily enter the circumferential direction of the cable by capillary action, so that the alarm line 8 can be reached in a short time, and the alarm line 8 can be detected quickly and reliably.

  Next, Example 5 will be described following Example 4. The configuration of the cable 41 with an alarm line according to the fifth embodiment is the same except for the first presser winding tape 6 and the second presser winding tape 7 in the cable 1 with an alarm line according to the first embodiment. Hereinafter, in description of the cable 41 with an alarm line which concerns on Example 5, the same thing as what is used with the cable 1 with an alarm line which concerns on Example 1 attaches | subjects the same code | symbol, and attaches | subjects the same code | symbol The description of is omitted.

  In the cable 41 with an alarm line according to the fifth embodiment, the first press winding tape 46 and the second press winding tape 47 that are in contact with the alarm line 8 are connected to the first press winding tape 6 and the second press winding tape 47 of the first embodiment. A material selected from materials that can be used for the press-wound tape 7 is used. The first presser winding tape 46 is made of a tape that is harder to tear than the second presser winding tape 47. In order to make the first presser winding tape 46 more difficult to tear than the second presser winding tape 47, the first presser winding tape 46 has a tape having a higher strength than the second presser winding tape 47. It is used. The tape strength of the first presser winding tape 46 is preferably 1.5 to 3 times the tape strength of the second presser winding tape 37. This is because it is difficult for the first press-winding tape 36 to be more difficult to tear than the second press-winding tape 37 when the tape strength is less than 1.5 times. On the other hand, when the tape strength exceeds three times, the first presser winding tape 36 can be more difficult to tear than the second presser winding tape 37, but the strength of the cable is increased and the flexibility of the cable is hindered. Because it comes out.

  According to the cable 41 with alarm line of the fifth embodiment obtained as described above, even if the cable is damaged and the second presser winding tape 47 is torn, the first presser winding tape 46 is not easily torn. . Therefore, the water that has entered the cable is retained between the first presser winding tape 46 and the second presser winding tape 47, and the first presser winding tape 46 and the second presser winding tape 47 overlap. In the gap formed in this way, it is possible to easily enter the circumferential direction of the cable by capillary action, so that the alarm line 8 can be reached in a short time, and the alarm line 8 can be detected quickly and reliably.

The perspective view which shows one Example of the cable with an alarm line which concerns on this invention. The cross-sectional view which shows the structure of the cable with an alarm line which concerns on Example 1 of this invention. The cross-sectional view which expanded a part of structure of the cable with an alarm line shown in FIG. The cross-sectional view which shows the structure of the press-wound tape of the cable with an alarm line which concerns on Example 2 of this invention. The cross-sectional view which shows the structure of the press-wound tape of the cable with an alarm line which concerns on Example 3 of this invention. The perspective view which shows the conventional cable with an alarm wire. The cross-sectional view which shows the structure of the conventional cable with an alarm line. The cross-sectional view which expanded a part of structure of the cable with an alarm line shown in FIG.

Explanation of symbols

1 ... Cable with alarm line 2 ... Conductor 3 ... Insulator 4 ... Insulated wire core 5 ··················· Interlace 6 ································· 1 ... Alarm line 9 ... Sheath

Claims (6)

A first presser wound tape wound on a wire core obtained by twisting a plurality of insulated wire cores;
A second presser wound tape wound on the first presser wound tape;
An alarm line vertically attached between the first presser wound tape and the second presser wound tape;
A sheath coated on the second presser wound tape;
A cable with an alarm line, characterized by comprising:   The cable with an alarm line according to claim 1, wherein the first presser winding tape and the second presser winding tape have a water supply rate of 0.5% or less (24 hours).   3. The alarm according to claim 1, wherein at least one of the first press-wound tape and the second press-wound tape is a tape in which a surface of the tape in contact with the alarm line is hydrophilized. Cable with wire.   4. The tape according to claim 1, 2, or 3, wherein at least one of the first presser winding tape and the second presser winding tape is a tape having a concavo-convex shape on a surface side in contact with the alarm line. Cable with alarm line as described.   5. The cable with an alarm line according to claim 1, wherein the first presser winding tape is thicker than the second presser winding tape.   The cable with an alarm line according to claim 1, 2, 3, 4, or 5, wherein the first presser winding tape has a strength higher than that of the second presser winding tape.

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