JP2018011457A - Method for repairing directly-buried cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for repairing a directly-buried cable that can restore it in a short time without stopping a communication service when the cable is struck by disaster.SOLUTION: A method is for repairing a directly-buried cable 1 including an inner first sheath (internal sheath 22) and a second sheath (reinforced external covering 10), in which the second sheath is loosely fitted over the first sheath. The method includes the steps of: identifying a damaged part of the second sheath; and covering a damaged range of the second sheath with a cylindrical member (repairing sheath 30) having a notched portion formed along a cable longitudinal direction.SELECTED DRAWING: Figure 3C

Description

  The present invention relates to a method for repairing a direct embedment cable, and more specifically, a direct embedment cable that includes an inner first sheath and an outer second sheath, and the second sheath is loosely fitted to the first sheath. It relates to the repair method.

  In Japan, efforts are being made to eliminate the use of utility poles from the viewpoints of improving road disaster prevention, securing safe and comfortable traffic spaces, creating good landscapes and promoting tourism. Currently, a method of laying electric wires in underground pipes (also referred to as an electric wire co-groove method) is most often used for this effort to eliminate electric poles. However, this method is difficult to embed pipes on roads with narrow sidewalks or roads without sidewalks, and the application cost is limited due to high equipment costs.

One of the methods to solve the difficulty of burial of pipes and the increase in equipment costs in these undergrounding methods is the method of burying wires directly in the soil (especially because lower costs can be expected) The application of the direct burial method is also being considered.
However, when a communication cable is directly buried in the soil, there is a concern that the cable may be damaged or bent due to cable compression due to earth pressure, thereby adversely affecting the transmission characteristics and mechanical characteristics of the cable.

  For example, Patent Document 1 discloses a direct-embedded optical fiber cable in which an outer sheath formed by winding a high-hardness / high-rigidity plastic tape on a core cable and integrated with an outer sheath on the outer sheath is disclosed. Has been.

JP-A-7-33478

  However, the optical fiber cable described in Patent Document 1 is reinforced with a high-hardness plastic tape to withstand earth pressure, and the cable core is tightly fixed to the exterior. There was a problem that it was difficult to repair and maintain. That is, when repairing and maintaining the optical cable core, it is necessary to bury the entire cable after digging up a range corresponding to the entire length of the cable, and thus it may take a great deal of time and money to recover.

Also, when replacing only the repaired part with a new optical cable core, after digging up the range, install a new closure, etc., and the optical fiber of the optical cable core that does not require repair and the optical fiber of the new optical cable core Are all connected, making recovery in a short time difficult. The communication service is stopped until it is restored, so there is a high possibility that it will not be allowed by the user.
In addition, there is a method of laying a hard duct and then laying an optical fiber cable in the duct, but in that case, the duct and the optical fiber cable are separately laid, and the laying man-hour is almost 2 Double.

  Therefore, it is conceivable that the optical cable core is kept loose relative to the exterior so that repair and maintenance can be completed in a short time, and the optical cable core can be easily pulled out and inserted from the exterior. Even so, it is desirable to restore the communication service in a short time without stopping the communication service when the cable for direct burying is damaged (also called failure).

  The present invention has been made in view of the above situation, and an object thereof is to provide a method for repairing a direct buried cable that can be restored in a short time without stopping a communication service in the event of a disaster. To do.

  The direct burying cable repair method according to one aspect of the present invention includes an inner first sheath and an outer second sheath, and the second sheath is loosely fitted to the first sheath. A method for repairing a cable, the step of identifying a damaged portion of the second sheath, and the step of covering the damaged range of the second sheath with a tubular member having a notch formed along the longitudinal direction of the cable Including.

  According to the above, it is possible to repair the buried cable directly in a short time without stopping the communication service.

It is a perspective view which shows an example of the cable for direct embedment concerning one embodiment of the present invention. It is a front view of the cable for direct burial. It is a figure which shows the damage of the cable for direct burial. It is a figure which shows the excavation of the both ends of a damaged part. It is a figure which shows installation of the sheath for repair. It is a figure which shows protection by a tape. It is a figure which shows the state which repair was completed. 3 is a diagram for explaining an example of a repair sheath of Example 1. FIG. It is a figure for demonstrating another example of the sheath for repair. It is a figure for demonstrating the jig | tool which mounts the sheath for repair. It is a figure which shows removal of a damaged part. It is a figure which shows installation of the sheath for repair. It is a figure which shows protection by a tape. It is a figure which shows removal of a damaged part. It is a figure which shows installation of the sheath for repair. It is a figure for demonstrating another example of the sheath for repair.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
A method of repairing a direct burying cable according to an aspect of the present invention includes (1) an inner first sheath and an outer second sheath, and the second sheath is loosely fitted to the first sheath. A method of repairing a direct embedment cable, the step of identifying a damaged portion of the second sheath, and a tubular member having a notch portion formed along the longitudinal direction of the cable, the damage range of the second sheath being specified Covering with a step.
Since the second sheath is repaired without changing the first sheath, it is possible to provide a method for repairing a direct burying cable that can be completed in a short time without stopping the communication service.
The damaged range of the second sheath means a place where the second sheath is damaged or a damaged part of the second sheath.

(2) The damaged portion of the second sheath is located in the damaged area by the cylindrical member formed in the cable longitudinal direction longer than the damaged area of the second sheath without cutting the damaged portion of the second sheath. Cover the part. Since the damaged second sheath can be left as it is, the construction period can be shortened compared with the case where the second sheath is removed.
(3) The cylindrical member has a slit formed along the longitudinal direction of the cable. Since one cylindrical member is sufficient, the number of parts required for repair work can be reduced as compared with the case where the damaged second sheath is covered with a plurality of parts.
(4) When the damaged portion of the second sheath is covered with the cylindrical member, the slit is disposed at a position different from the damaged portion of the second sheath. Since the position of the slit and the damaged portion of the second sheath are not matched, it is possible to prevent the strength of the repaired portion from being lowered.

(5) The method further includes a step of excising a damaged portion of the second sheath located in the damage range to expose the first sheath, wherein the cylindrical member is composed of one or a plurality of main cylindrical members, The main tubular member covers a portion of the second sheath that has been excised, and the main tubular member covers the first sheath exposed by excision of the damaged portion of the second sheath. The damaged portion of the second sheath is excised and the main tubular member reliably covers the excised portion of the damaged portion of the second sheath and the first sheath is not exposed, so that the first sheath can be reliably protected.
(6) The method further includes a step of exposing the first sheath by cutting a damaged portion of the second sheath located in the damage range, wherein the cylindrical member includes one or a plurality of main cylindrical members, and a plurality of the cylindrical members. An auxiliary cylindrical member, and the main cylindrical member covers a portion of the second sheath that has been excised, and the auxiliary cylindrical member allows the main cylindrical members or the main cylindrical member and the A seam with the second sheath is covered, and the first sheath exposed by excision of the damaged portion of the second sheath is covered with the main cylindrical member and the auxiliary cylindrical member. The damaged portion of the second sheath is excised, the main tubular member and the auxiliary tubular member reliably cover the excised portion of the damaged portion of the second sheath, and the first sheath is not exposed. It can be reliably protected.
(7) The method further includes a step of excising a damaged portion of the second sheath located in the damaged area to expose the first sheath, wherein the cylindrical member is disposed on both sides of the cut damaged portion in the cable longitudinal direction. Each of the second sheaths that are positioned is formed to have a length that partially overlaps, and the tubular member covers the first sheath exposed by excision of the damaged portion of the second sheath. Since the damaged portion of the second sheath is excised and the tubular member reliably covers the excised portion of the damaged portion of the second sheath and the first sheath is not exposed, the first sheath can be reliably protected.
(8) The cylindrical member has a slit formed along the longitudinal direction of the cable. Since one cylindrical member is sufficient, the number of parts required for repair work can be reduced as compared with the case where the damaged second sheath is covered with a plurality of parts.
(9) When the exposed first sheath is covered with the cylindrical member, the slit is disposed on the side opposite to the ground surface. Since the cable is dug from the ground surface side, the external force to the cable is often generated from the ground surface side, and if the slit is placed on the opposite side of the ground surface, there will be no impact of a shovel or the like on the slit portion. It is possible to prevent the strength of the repaired portion from being lowered.
(10) The cylindrical member is formed by combining two or more members having a C-shaped cross section having a notch portion at a part thereof, so that the notch portions of the respective C-shaped members are not overlapped. Are alternately arranged to cover the exposed first sheath. Compared to the case of using a closed annular member, it is easier to form a cylindrical member, and since the C-shaped cutouts are arranged so as not to overlap, it is possible to prevent the strength of the repaired portion from being lowered.

[Details of the embodiment of the present invention]
Hereinafter, a specific example of a method for repairing a direct burying cable according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an example of a direct burying cable according to an embodiment of the present invention, and FIG. 2 is a front view of the direct burying cable.
The direct burying cable 1 includes an optical cable core 20 and a reinforced outer jacket 10 disposed outside the optical cable core 20.

  Although details of the optical cable core 20 are not shown, the optical cable core 20 has a core portion 21 of about 8 cores such as a drop cable for dropping a subscriber. The periphery of the core portion 21 is covered with an inner sheath 22 made of, for example, PE (polyethylene), PVC (polyvinyl chloride), or the like. The inner sheath 22 corresponds to the first sheath of the present invention.

The optical cable core 20 (inner sheath 22) has an outer diameter of about 4 mm to 20 mm, and the optical cable core 20 is formed in a round shape, for example.
The core portion 21 is a cable in which the outer side of a cable (for example, up to about 200 cores) bundled with multi-fiber optical fiber ribbons or the like, such as a low-comfort cable for a branch line, is held with a press-wound tape or the like. There may be.
The core portion 21 may be a slot cable or a slotless cable, and the shape thereof is not limited as long as it is a multi-core optical fiber cable.

The reinforced jacket 10 is loosely fitted to the optical cable core 20 and covers the periphery of the optical cable core 20 to protect the optical cable core 20. The reinforced outer jacket 10 corresponds to the second sheath of the present invention.
The reinforced outer jacket 10 is made of hard plastic such as high density polyethylene (HDPE). If the reinforced casing 10 is made of HDPE, that is, polyethylene having a density of 0.942 (g / cm ³ ) or more, it can sufficiently withstand the compressive force and bending force applied to the cable due to earth pressure.

Further, the reinforced jacket 10 may be a metal such as iron or SUS. If the reinforced casing 10 is made of metal, it can sufficiently withstand the compressive force and bending force applied to the cable due to earth pressure, as described above, but in consideration of handleability, hard plastic is preferred.
Alternatively, the reinforced outer jacket 10 may be formed of a hard plastic whose main material is polypropylene (PP). If the reinforced casing 10 is made of PP, the required strength can be maintained even if the allowable wall thickness is small compared to the case of forming it with HDPE.

  Further, the reinforced outer jacket 10 is formed in, for example, a bellows shape, and a longitudinal section thereof is formed in a waveform. Specifically, the reinforced outer jacket 10 has ridges 11 and valleys 12 formed along a direction orthogonal to the longitudinal direction, and these ridges 11 and valleys 12 are alternately provided along the longitudinal direction of the cable. It has been. In addition, the inner diameter of the reinforced outer jacket 10 (the valley portion 12) is configured to be about 30 mm, and the reinforced outer jacket 10 is also formed in a round shape, for example.

  As described above, the inner sheath 22 of the optical cable core 20 is loose with respect to the reinforced jacket 10, and the optical cable core 20 is easily pulled out of the reinforced jacket 10 when the optical cable core 20 is repaired or maintained. In addition, since the new optical cable core 20 can be easily inserted into the reinforced jacket 10, the optical cable core 20 can be repaired and maintained in a short time.

In addition, if the reinforced jacket 10 is formed into a corrugated shape, it can withstand earth pressure, and the ridges 11 and the valleys 12 formed alternately can provide the same flexibility as a general optical cable. Can be handled easily.
In addition, in the figure, although the example of the bellows-shaped reinforcement | strengthening envelope which the direction of a mountain valley is orthogonal to a longitudinal direction was mentioned and demonstrated, the reinforcement type | mold jacket of this invention is a spiral shape which the direction of a mountain valley intersects with a longitudinal direction. It may be a bellows. It is also possible to form one of the outer peripheral surface and the inner peripheral surface of the reinforced outer jacket flat and make the other corrugated.

  By the way, as described above, the inner sheath 22 of the optical cable core 20 is in a loose state with respect to the reinforced jacket 10, but even in such a structure, the reinforced jacket 10 and the optical cable core 20 are temporarily provided. In the event of a disaster, it is desirable to restore the communication service in a short time without stopping the communication service. Therefore, the following construction method was created.

3A to 3E are diagrams for explaining the repair method of the first embodiment, and FIG. 4A is a diagram for explaining an example of the repair sheath of the first embodiment. In the first embodiment, the direct burying cable 1 is buried in the soil between manholes (or handholes, the same shall apply hereinafter) 55a and 55b. The optical fiber of the optical cable core 20 of the cable 1 and the optical fiber of the existing optical cable core 50 are connected. For example, it is assumed that the bucket of the construction machine directly touches the burying cable 1 and the reinforced jacket 10 is slightly damaged, but the optical cable core 20 is not damaged.
In order to clarify the optical cable core 20 in the reinforced jacket 10, in the following drawings, the optical cable core 20 is shown so as to be visible even when it is arranged inside the reinforced jacket 10.

When the reinforced outer jacket 10 is damaged as described above, first, a damaged portion of the reinforced outer jacket 10 is specified as shown in FIG. 3A. Thereafter, as shown in FIG. 3B, soil around the damaged portion (about several meters) is dug out.
Next, as shown in FIG. 3C, the repairing sheath 30 covers the damaged area of the reinforced outer jacket 10. The repair sheath 30 corresponds to the tubular member of the present invention.

The repair sheath 30 is formed of, for example, substantially the same material and the same shape as the reinforced outer jacket 10. Since the repair sheath 30 has the same strength and reliability as the reinforced jacket 10, even if the reinforced jacket 10 is repaired, the cable can be directly buried without being damaged.
Further, the repair sheath 30 of this embodiment may have the same diameter as the outer diameter of the reinforced outer jacket 10 or an inner diameter larger than the outer diameter of the reinforced outer jacket 10 (for example, up to about 10 mm). The inner diameter of the reinforcing casing 10 may be longer than the damage range of the reinforced casing 10.

As shown in FIG. 4A, a slit 31 is formed in the repair sheath 30 of the present embodiment along the cable longitudinal direction, and the repair sheath 30 can be opened at the position of the slit 31. The slit 31 corresponds to a notch portion of the present invention.
In order to cover the damaged portion of the reinforced outer jacket 10 with the repair sheath 30, it is easy to use a sheath mounting jig, for example. Various structures are known for this jig. For example, as shown in FIG. 5A, the jig 70 includes a cylindrical cable insertion portion 71, a rod-shaped sheath guide portion 72, and the like. Consists of The sheath guide part 72 extends obliquely from the cable insertion part 71 and is connected to the outer surface of the cable insertion part 71.

  As shown in FIG. 5B, the cable insertion portion 71 can be opened and closed, for example. When a cable is placed on the opened cable insertion portion 71 and then closed, the cable can be set therein. On the other hand, the sheath 30 for repair described with reference to FIG. 4A is inserted into the sheath guide portion 72. At this time, as shown in FIG. 5C, the slit 31 is arranged facing the cable. When the repair sheath 30 is advanced toward the cable insertion portion 71 and the slit 31 of the repair sheath 30 contacts the sheath guide portion 72, the repair sheath 30 opens at the position of the slit 31. When the repair sheath 30 is further advanced, the slit 31 is closed at the tip of the cable insertion portion 71, so that the cable (the damaged portion of the reinforced outer jacket 10) can be covered.

In addition, after covering the damaged portion of the reinforced outer jacket 10 with the repair sheath 30, for example, for repairing, the slit 31 of the repair sheath 30 is arranged at a position different from the damaged portion of the reinforced outer jacket 10. The sheath 30 may be rotated around its axis. Since the position of the slit 31 and the damaged portion of the reinforced outer jacket 10 do not coincide with each other, it is possible to prevent the strength of the repaired portion from being lowered.
As shown in FIG. 4B, the repair sheath 30 may be one having a positional relationship in which the one end side and the other end side that form the slit 31 just face each other. After selecting a large-diameter repair sheath and covering the cable, the one end side and the other end side forming the slit 31 may overlap in the radial direction.

  Subsequently, as illustrated in FIG. 3D, the repairing sheath 30 is protected by winding a protective tape 33 around the repairing sheath 30. The protective tape 33 is, for example, a self-bonding tape, and is wound around the repair sheath 30 and then heated, for example, with a heat gun, so that it is dissolved and strongly bonded to the repair sheath 30. In addition, after winding with this self-bonding tape, you may wind further with a vinyl tape.

Thereafter, as shown in FIG. 3E, when the excavated soil is returned and the repair sheath 30 is filled (also referred to as covering soil), a series of repair work is completed.
According to this repair method, the optical cable core 20 is repaired as it is, and only the reinforced outer jacket 10 is repaired. Therefore, the communication service can be performed in a short time without stopping.
Further, since the damaged reinforced outer jacket 10 can be left as it is, the construction period can be shortened compared with the case where the reinforced outer jacket 10 is removed. Furthermore, since one repair sheath 30 is sufficient, the number of parts required for repair work can be reduced as compared to the case where the reinforced outer jacket 10 damaged by a plurality of parts is covered.

  In addition, in the said Example, the example of the repair sheath 30 with a slit was given and demonstrated. However, for example, as shown in FIG. 4B, the repair sheath may be formed in a C-shaped cross section having a notch in a part thereof. Also in this example, after covering the damaged portion of the reinforced jacket with the repair sheath, the damaged portion of the reinforced jacket is not visible from the notched opening 30a (the damaged portion matches the opening). For example, the repair sheath may be rotated.

6A to 6C are diagrams for explaining the repair method according to the second embodiment.
When the reinforced outer jacket 10 is damaged as described above, first, a damaged portion of the reinforced outer jacket 10 is specified, and then the soil around the damaged portion is dug out.
Subsequently, as shown in FIG. 6A, the damaged portion of the reinforced outer jacket 10 is excised. More specifically, for example, a tool such as a cutter is used to cut both ends in the cable longitudinal direction at the damaged portion of the reinforced outer jacket 10, and the reinforced outer jacket 10 connected to one manhole 55a and the reinforced continuous to the other manhole 55b. Separated into a mold jacket 10. When the damaged portion of the reinforced outer jacket 10 is removed, the optical cable core 20 is exposed.

Next, as shown in FIG. 6B, the repairing sheath 30 covers the optical cable core 20 exposed by removing the damaged portion of the reinforced outer jacket 10.
The repair sheath 30 includes, for example, one main cylindrical member 30b and two auxiliary cylindrical members 30c. The main cylindrical member 30b is formed, for example, in the same shape with the same material as that of the reinforced casing 10 and is formed to have substantially the same diameter as the reinforced casing 10. Moreover, the slit is formed similarly to Example 1. FIG. Therefore, the optical cable core 20 is covered with the repair sheath 30 using the jig 70 described in FIG.

  On the other hand, the auxiliary cylindrical member 30c may have the same diameter as the outer diameter of the reinforced casing 10, but may have an inner diameter larger than the outer diameter of the reinforced casing 10. Good. In any case, a slit is formed in the auxiliary cylindrical member 30c as in the first embodiment, and the slit is expanded to cover the seam. Specifically, as shown in FIG. 6B, one auxiliary cylindrical member 30c is formed by using the jig 70 described in FIG. 5 and the end of the reinforced outer jacket 10 connected to one manhole 55a and the main cylindrical shape. Cover the seam with the end of member 30b. The other auxiliary cylindrical member 30c uses the jig 70 described in FIG. 5 to cover the seam between the end of the reinforced outer jacket 10 connected to the other manhole 55b and the end of the main cylindrical member 30b.

Subsequently, as shown in FIG. 6C, a protective tape 33 is wound around the main cylindrical member 30b and the auxiliary cylindrical member 30c to protect the repair sheath 30. After that, when the excavated soil is returned and the repair sheath 30 is filled, a series of repair work is completed.
6A to 6C, the example of one main cylindrical member 30b has been described, but a plurality of main cylindrical members may be configured. In this case, the seam between adjacent main cylindrical members is covered with a new auxiliary cylindrical member.

Moreover, you may cover the excision part of the reinforcement | strengthening-type jacket 10 only by the main cylindrical member, without using an auxiliary | assistant cylindrical member. Specifically, the optical cable core 20 is covered with the main tubular member 30b having substantially the same length as the cut-out reinforced outer jacket 10, and slightly occurs between the end of the reinforced outer jacket 10 and the main cylindrical member 30b. A protective tape 33 is wrapped around the gap 30 to protect the repair sheath 30 and the ends of the reinforced jacket 10.
In addition, after covering the optical cable core 20 with the repairing sheath 30, the slit 31 of the repairing sheath 30 is on the side opposite to the ground surface and is not visible to the operator (for example, the position facing the bottom portion of the dug cable) For example, the repair sheath 30 may be rotated about its axis. Since the cable is dug from the ground surface side, the external force to the cable is often generated from the ground surface side, and if the slit is placed on the opposite side of the ground surface, there will be no impact of a shovel or the like on the slit portion. It is possible to prevent the strength of the repaired portion from being lowered.

7A and 7B are diagrams for explaining a repair method according to the third embodiment. In the third embodiment, for example, when the bucket of the construction machine directly touches the burying cable 1 and the reinforced jacket 10 is significantly damaged, for example, this damage may affect the optical cable core 20. Is assumed.
Also in the third embodiment, as in the first and second embodiments, when the reinforced outer jacket 10 is damaged, first, a damaged portion of the reinforced outer jacket 10 is specified, and then the soil around the damaged portion is dug out. .

  Subsequently, as shown in FIG. 7A, the damaged portion of the reinforced outer jacket 10 is excised. More specifically, for example, a tool such as a cutter is used to cut both ends in the cable longitudinal direction at the damaged portion of the reinforced outer jacket 10, and the reinforced outer jacket 10 connected to one manhole 55a and the reinforced continuous to the other manhole 55b. Separated into a mold jacket 10. When the damaged portion of the reinforced outer jacket 10 is removed, the optical cable core 20 is exposed.

Next, as shown in FIG. 7B, the repairing sheath 30 covers the optical cable core 20 exposed by removing the damaged portion of the reinforced jacket 10.
Similarly to the first and second embodiments, the repair sheath 30 is formed of, for example, substantially the same material and the same shape as the reinforced outer jacket 10, and the diameter thereof is the same as the outer diameter of the reinforced outer jacket 10. Alternatively, the inner diameter of the reinforced outer jacket 10 may be larger than the outer diameter. The repair sheath 30 of the third embodiment is also provided with slits 31 as in the first and second embodiments. Therefore, the optical cable core 20 is covered with the repair sheath 30 using the jig 70 described in FIG.

  The repair sheath 30 of the third embodiment is formed longer than the removed reinforced outer jacket 10. Therefore, as shown in FIG. 7B, the repair sheath 30 includes the ends of the reinforced outer jacket 10 connected to the one manhole 55a, which are located at both ends in the cable longitudinal direction of the removed reinforced outer jacket 10, respectively. Both ends of the reinforced outer jacket 10 connected to the manhole 55b are partially covered.

  In addition, after covering the optical cable core 20 with the repairing sheath 30, the slit 31 of the repairing sheath 30 is on the side opposite to the ground surface and is not visible to the operator (for example, the position facing the bottom portion of the dug cable) For example, the repair sheath 30 may be rotated about its axis. Since the cable is dug from the ground surface side, the external force to the cable is often generated from the ground surface side, and if the slit is placed on the opposite side of the ground surface, there will be no impact of a shovel or the like on the slit portion. It is possible to prevent the strength of the repaired portion from decreasing.

Subsequently, as in the first and second embodiments, the repairing sheath 30 is protected by wrapping the protective tape 33 around the repairing sheath 30. After that, when the excavated soil is returned and the repair sheath 30 is filled, a series of repair work is completed.
According to this repair method, the repair sheath 30 is formed to a length that covers both ends of the damaged portion of the reinforced jacket 10 and the optical cable core 20 is not exposed, so that the optical cable core 20 can be reliably protected.

FIG. 8 is a view for explaining still another example of the repair sheath.
In the first to third embodiments, the example of the single repair sheath 30 has been described. However, the repair sheath may be a combination of two or more members having different diameters. Specifically, as shown in FIG. 8, the repair sheath 30 includes a first member 41 and a second member 42, and both the first member 41 and the second member 42 are cut into a part thereof. It is formed in a C-shaped cross section having a notch. In addition, the 1st member 41 and the 2nd member 42 are equivalent to the member of a cross-sectional C shape of this invention.

  Then, for example, the first member 41 covers the exposed optical cable core 20 with the cutout opening 41a facing upward, and the second member 42 moves the cutout opening 42a downward. The exposed optical cable core 20 is covered in a facing posture. As described above, according to the structure that covers the optical cable core 20 by alternately arranging the openings 41a and 42a so as not to overlap with each other, it is easier to form a repair sheath than when using a closed annular member, Since the openings are arranged so as not to overlap, it is possible to prevent the strength of the repaired portion from being lowered. Note that the opening 41a and the opening 42a correspond to a notch of the present invention.

  In addition, although the case where this invention was applied to the optical cable core was demonstrated as embodiment, a metal cable core may be sufficient instead of an optical cable core.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 ... Cable for direct embedment, 10 ... Reinforced type jacket, 11 ... Mountain part, 12 ... Valley part, 13 ... Opening end part, 20 ... Optical cable core, 21 ... Core part, 22 ... Inner sheath, 30 ... Sheath for repair 30a, 41a, 42a ... opening, 30b ... main cylindrical member, 30c ... auxiliary cylindrical member, 31 ... slit, 33 ... protective tape, 41 ... first member, 42 ... second member, 45 ... existing closure, DESCRIPTION OF SYMBOLS 50 ... Existing optical cable core, 55a, 55b ... Manhole, 70 ... Jig for sheath mounting, 71 ... Cable insertion part, 72 ... Sheath guide part.

Claims (10)

A method for repairing a direct burying cable comprising an inner first sheath and an outer second sheath, the second sheath being loosely fitted to the first sheath,
Identifying a damaged portion of the second sheath;
Covering the damaged range of the second sheath with a cylindrical member having a notch formed along the longitudinal direction of the cable.   The damaged portion of the second sheath is not excised, and the damaged portion of the second sheath located in the damaged range is covered with the tubular member formed longer in the cable longitudinal direction than the damaged range of the second sheath. The method for repairing a direct burying cable according to claim 1.   The method for repairing a direct burying cable according to claim 1 or 2, wherein the cylindrical member has a slit formed along a longitudinal direction of the cable.   The method for repairing a direct burying cable according to claim 3, wherein when the cylindrical member covers the damaged portion of the second sheath, the slit is arranged at a position different from the damaged portion of the second sheath. Further comprising excising a damaged portion of the second sheath located in the damaged area to expose the first sheath;
The tubular member includes one or a plurality of main tubular members, the main tubular member covers a portion of the second sheath that has been cut out, and the damaged portion of the second sheath is covered by the main tubular member. The method for repairing a direct burying cable according to claim 1, wherein the first sheath exposed by excision is covered. Further comprising excising a damaged portion of the second sheath located in the damaged area to expose the first sheath;
The cylindrical member includes one or a plurality of main cylindrical members and a plurality of auxiliary cylindrical members, and the main cylindrical member covers the excised portion of the second sheath, and the auxiliary cylindrical shape By covering the seam between the main tubular members or between the main tubular member and the second sheath by a member, the damaged portion of the second sheath is excised by the main tubular member and the auxiliary tubular member. The method for repairing a direct burying cable according to claim 1, wherein the exposed first sheath is covered. Further comprising excising a damaged portion of the second sheath located in the damaged area to expose the first sheath;
The tubular member is formed to have a length that partially overlaps each of the second sheaths located on both sides of the cut portion of the damaged portion in the cable longitudinal direction, and the tubular member has a length of the damaged portion of the second sheath. The method for repairing a direct burying cable according to claim 1, wherein the first sheath exposed by excision is covered.   The method for repairing a direct burying cable according to any one of claims 5 to 7, wherein the cylindrical member has a slit formed along a longitudinal direction of the cable.   The method for repairing a direct burying cable according to claim 8, wherein the slit is disposed on a side opposite to a ground surface when the exposed first sheath is covered with the tubular member. The cylindrical member is formed by combining two or more members having a C-shaped cross section having a notch portion at a part thereof, and alternately so that the notch portions of the respective C-shaped members are not overlapped. The method for repairing a direct burying cable according to claim 5, wherein the cable is disposed and covers the exposed first sheath.

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