JP2015162995A - Submarine cable connection structure, reinforcement structure of connection part of submarine cable and connection method of submarine cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a submarine cable connection structure, a reinforcement structure of connection part of submarine cable and a connection method of submarine cable capable of preventing a cable from being bent at an end of a cable connection part in an axial direction of the cable.SOLUTION: The submarine cable connection structure includes: a cable connection part for connecting two cables which are laid on the bottom; a first cover part which is connected to an end part of the cable connection part in an axial direction of the cable, through which a cable is inserted, and which is arranged so that the external diameter gets closer to the diameter of the cable from the cable connection part toward the opposite side; and a second cover part which is engaged with the first cover part on the outer side, through which the cable is inserted, which is arranged so that the external diameter gets closer to the diameter of the cable from the cable connection part toward the opposite side, and which has a coefficient of elasticity smaller than the coefficient of elasticity of the first cover part.

Description

  The present invention relates to a submarine cable connection structure, a reinforcing structure of a submarine cable connection portion, and a submarine cable connection method.

  When laying a cable between land via the ocean or the like, the cable is laid from the laying ship toward the bottom of the water (the bottom of the sea). At this time, in order to connect the two cables laid on the water bottom (sea floor), for example, a cable connecting portion as in Patent Document 1 is provided.

  Patent Document 2 discloses that an end face material and a rubber boot are provided at the end of the connection portion of the optical cable.

JP 2006-345623 A JP 2005-215413 A

  In the cable connecting portion, the portion where the end portions of the two cable cores facing each other in the axial direction are connected is covered with a protective tube or the like, so the outer diameter of the cable connecting portion is larger than the diameter of the cable. A step is formed at the end of the cable connecting portion in the axial direction of the cable, and this step becomes a rigid inflection point. For this reason, when a cable bending force is applied when laying the cable or after the cable is laid, the cable bending force is concentrated at the cable axial end of the cable connecting portion, and the cable is broken ( There is a possibility that corner breakage may occur.

  An object of the present invention is to provide a bottom-floor cable connection structure, a bottom-floor cable connection portion reinforcement structure, and a bottom-floor cable connection in which a phenomenon that the cable is bent (corner breakage) is prevented from occurring at the end of the cable connection portion in the axial direction of the cable. Is to provide a method.

According to a first aspect of the invention,
A cable connection for connecting two cables laid on the bottom of the water;
The cable connection portion is connected to the end portion side of the cable in the axial direction, the cables of the two cables are inserted therein, and the outer diameter from the cable connection portion side to the opposite side is the diameter of the cable. A first covering portion that is small to approach
The cable is inserted into the outside of the first covering portion, the cable is inserted therein, and the outer diameter decreases from the cable connecting portion side to the opposite side so as to approach the diameter of the cable. A second covering portion having an elastic modulus smaller than the elastic modulus of the covering portion;
A submarine cable connection structure is provided.

According to a second aspect of the invention,
A cable connecting portion for connecting two cables laid on the bottom of the water is connected to the axial end side of each of the two cables, the cable is inserted into the inside, and the opposite side from the cable connecting portion side A first covering portion whose outer diameter is reduced toward the diameter of the cable toward the
The cable is inserted into the outside of the first covering portion, the cable is inserted therein, and the outer diameter decreases from the cable connecting portion side to the opposite side so as to approach the diameter of the cable. A second covering portion having an elastic modulus smaller than the elastic modulus of the covering portion;
A submarine cable connection reinforcement structure is provided.

According to a third aspect of the invention,
Forming a cable connecting portion by connecting two cables laid on the bottom of the water;
In a state where the cable is inserted through the first covering portion whose outer diameter is reduced so as to approach the diameter of each of the two cables from the cable connecting portion side to the opposite side, Connecting one covering portion to an end portion side of the cable connecting portion in the axial direction of the cable;
The cable has an outer diameter that decreases from the cable connecting portion side to the opposite side so as to approach the diameter of the cable, and has an elastic modulus smaller than that of the first covering portion. In a state where the second covering portion is fitted to the outside of the first covering portion,
A method of connecting a submarine cable having

  ADVANTAGE OF THE INVENTION According to this invention, the bottom cable connection structure which suppressed the phenomenon (corner bend) that a cable bends in the axial direction edge part of a cable connection part, the reinforcement structure of a bottom cable connection part, and the connection of a bottom cable A method is provided.

It is sectional drawing which shows the bottom cable connection structure which concerns on 1st Embodiment of this invention. It is sectional drawing to which a part of FIG. 1 was expanded. It is a schematic diagram which shows an external appearance when the water bottom cable connection structure which concerns on 1st Embodiment of this invention is decomposed | disassembled. It is sectional drawing to which some submerged cable connection structures concerning 2nd Embodiment of this invention were expanded. It is sectional drawing to which a part of submarine cable connection structure concerning a 3rd embodiment of the present invention was expanded. It is a schematic diagram which shows an external appearance when the water bottom cable connection structure which concerns on 3rd Embodiment of this invention is decomposed | disassembled.

<First Embodiment of the Present Invention>
(1) Submarine cable connection structure The submarine cable connection structure which concerns on 1st Embodiment of this invention is demonstrated using FIGS. 1-3. FIG. 1 is a cross-sectional view showing a submarine cable connection structure according to the present embodiment. FIG. 2 is an enlarged cross-sectional view of a part of FIG. FIG. 3 is a schematic view showing an appearance when the bottom cable connection structure according to the present embodiment is disassembled. In FIG. 1, the submarine cable connection structure 10 is configured to be bilaterally symmetrical via a center line of a one-dot chain line.

  In the submarine cable connection structure 10 of the present embodiment, the cable breaks by having two covering portions (the first covering portion 500 and the second covering portion 600) at the end of the cable connecting portion 20 in the axial direction of the cable 100. A phenomenon (corner breakage) is configured to be suppressed. Details will be described below.

(Cable connection)
As shown in FIG. 1, the cable 100 laid on the bottom of the water is a so-called power / optical composite cable, and includes a power cable core 110 and an optical cable core (optical fiber) 120. An armor 130 made of iron wire is provided outside the power cable core 110 and the optical cable core 120. Note that an anticorrosion layer 140 may be provided outside the armor 130.

  The two cables 100 facing each other in the axial direction are connected at the cable connecting portion 20 in a state where they are peeled off stepwise from the anticorrosion layer 140 side. The cable connection unit 20 includes a power cable core connection unit 210 that connects the ends of the two power cable cores 110 and an optical cable core connection unit 220 that connects the ends of the two optical cable cores 120. .

  The power cable core 110 is a cross-linked polyethylene insulated PVC sheathed cable (CV cable), from the center side toward the outside, a conductor (not shown), an internal semiconductive layer (not shown), an insulation A layer (not shown), an external semiconductive layer (not shown), a shield layer (shield layer) (not shown), and a sheath (not shown). The end of the conductor of one power cable core 110 is connected to the end of the conductor of the other power cable core 110 by compressing a sleeve (not shown). An insulating tape is wound around the sleeve over the insulating layer of the power cable core 110. A metal tube (not shown) is provided so as to cover the insulating tape, and a protective tape is wound around the metal tube. The ends of the two power cable cores 110 are connected by the power cable core connection part 210 having the above-described configuration.

  The optical cable core 120 includes a tension member, a grooved spacer, an optical fiber provided in the groove of the grooved spacer, and a vinyl sheath from the center side toward the outside. The tension members at the ends of the two optical cable cores 120 are fixed by a metal body (tension member clamp) in a metal tube (sleeve). Also, the end of one optical fiber is fused with the end of the other optical fiber, and stored in a fiber tray in a metal tube so as not to be extremely bent. A metal tube is provided so as to cover the metal body for fixing the tension member and the fiber tray, and a protective tape is wound around the joint of the metal tube. The ends of the two optical cable cores 120 are connected by the optical cable core connection part 220 having the above-described configuration.

  Further, the armor 130 of the cable 100 peeled off in stages is fixed so that the iron wire is sandwiched between a wedge-shaped cotter 312 and a disk-shaped fixing plate (batch metal fitting) 310 that bends the iron wire along the outside. . The fixing plate 310 fixed to one cable 100 is connected to the fixing plate 310 fixed to the other cable 100 via the connection fitting 320. A cylindrical protective tube 330 is provided so as to surround the fixing plate 310, the cotter 312, the connection fitting 320, the power cable core connection part 210, and the optical cable core connection part 220. A fixed plate 310 and a cotter 312 are fixed inside the protective tube 330 on the end side in the axial direction of the cable 100. In the case where the protective tube 330 is filled with the waterproofing mixture 340 so as to fill the space between the fixing plate 310, the cotter 312, the coupling fitting 320, the power cable core connection part 210, and the optical cable core connection part 220. There is.

  As described above, the cable connection portion 20 is mainly configured by the power cable core connection portion 210, the optical cable core connection portion 220, the fixing plate 310, the cotter 312, the coupling fitting 320, the protective tube 330, and the like. The fixing plate 310, the cotter 312, the coupling fitting 320, the protective tube 330, and the like constituting the cable connection unit 20 are made of, for example, iron covered with an anticorrosion layer, and can be configured to withstand an impact when the cable 100 is laid. Is done.

(Flange part)
As shown in FIGS. 1 and 2, a flange portion 400 is coupled to an end portion of the cable connecting portion 20 in the axial direction of the cable 100. The flange portion 400 has a cylindrical portion 410 and a plate-like portion 420. The cylindrical portion 410 is fitted on the outer side of the protective tube 330 of the cable connecting portion 20. The cylindrical portion 410 is provided with a bolt insertion hole (not shown) at a position overlapping the protective tube 330. A bolt 430 is inserted into the bolt insertion hole from the outside of the cylindrical portion 410. The bolt 430 is screwed into a screw hole 332 provided in the protective tube 330 of the cable connection unit 20. As a result, the flange portion 400 is coupled to the cable connecting portion 20.

  On the opposite side of the cylindrical portion 410 to the cable connecting portion 20, a plate-like portion 420 is provided along a direction perpendicular to the axial direction of the cable 100. Inside the plate-like portion 420, a flange portion cable insertion hole 412 through which the cable 100 is inserted is provided along the axial direction of the cable 100. In addition, the plate-like portion 420 is provided with a bolt insertion hole (not shown) into which a bolt 540 for fixing the first covering portion 500 described later is inserted.

(First covering part (inner covering part))
As shown in FIGS. 1 and 2, a first covering portion (inner covering portion) 500 is coupled to the end portion of the cable connecting portion 20 in the axial direction of the cable 100 via a flange portion 400. The On the cable connecting portion 20 side of the first covering portion 500, a screw hole 552 is provided along the axial direction of the cable 100 at a position overlapping the bolt insertion hole provided in the plate-like portion 420 of the flange portion 400. Bolts 540 are inserted into bolt insertion holes provided in the plate-like portion 420 of the flange portion 400. The bolt 540 is screwed into the screw hole 552 of the first covering portion 500. Thus, the 1st coating | coated part 500 is connected to the edge part side of the axial direction of the cable 100 of the cable connection part 20 via the flange part 400 by fixing the 1st coating | coated part 500 to the flange part 400. Is done. Further, as described above, the first covering portion 500 is fixed to the plate-like portion 420 of the flange portion 400 by the bolts 540 provided along the axial direction of the cable 100, so that the first covering portion 500 is fixed to the first covering portion 500. When a force is applied from a direction perpendicular to the axial direction of the cable 100, the first covering portion 500 is prevented from being detached from the flange portion 400.

  The 1st coating | coated part 500 is truncated cone shape, for example. The outer diameter of the first covering portion 500 on the cable connecting portion 20 side is, for example, equal to the diameter of the protective tube 330 or the diameter of the flange portion 400 of the cable connecting portion 20. Moreover, the outer diameter of the 1st coating | coated part 500 is so small that it approaches the diameter of the cable 100 toward the opposite side from the cable connection part 20 side. Thereby, the level | step difference from the cable connection part 20 to the edge part on the opposite side to the cable connection part 20 of the 1st coating | coated part 500 is eased. Further, a screw hole 554 into which a bolt 620 for fixing the second covering portion 600 described later is screwed is provided on the inclined side surface of the first covering portion 500.

  Here, a first cable insertion hole 510 into which the cable 100 is inserted is provided in the first covering portion 500 along the axial direction of the cable 100.

  The first cable insertion hole 510 widens from the cable connecting portion 20 side toward the opposite side. When the cable 100 is laid or when a force for bending the cable 100 is applied after the cable 100 is laid, the cable 100 is gradually bent from the cable connecting portion 20 side toward the opposite side. Thereby, not only the phenomenon that the cable 100 bends (perpendicularly) at the end of the cable connection portion 20 in the axial direction of the cable 100 (square breakage) is suppressed, but also the cable connection of the first covering portion 500. Occurrence of the phenomenon that the cable 100 is bent (at a right angle) at the end opposite to the portion 20 (opening end of the first cable insertion hole 510) (square breakage) is suppressed. Further, the cable 100 is prevented from being damaged by the opening end of the first cable insertion hole 510.

  Note that the diameter of the base portion of the first cable insertion hole 510 on the cable connection portion 20 side is equal to the diameter of the cable 100. Thereby, it is possible to suppress the phenomenon that the cable 100 is bent at the base portion of the first cable insertion hole 510 on the cable connection portion 20 side (that is, the end portion of the cable connection portion 20 in the axial direction of the cable 100).

  The first cable insertion hole 510 has an R-shaped portion 520 on the opening side opposite to the cable connection portion 20. The cross-sectional shape of the R-shaped portion 520 when viewed from the direction perpendicular to the axial direction of the cable 100 is an R-shape that is convex toward the axial side of the cable 100. Since the R-shaped portion 520 is provided in the first cable insertion hole 510, when a force for bending the cable 100 is applied when the cable 100 is laid or after the cable 100 is laid, the cable 100 may be applied to the first cable insertion hole 510. As a result, the cable 100 is prevented from being damaged.

  The radius of curvature of the R-shaped portion 520 of the first cable insertion hole 510 is, for example, not less than the minimum bending radius of the cable 100. The minimum bend radius of the cable 100 is the minimum bend radius that can be bent without damaging the cable 100. When a force for bending the cable 100 is applied and the cable 100 is bent in close contact with the R-shaped portion 520, the bending radius of the cable 100 in the R-shaped portion 520 is smaller than the minimum bending radius allowed by the cable 100. It is suppressed that it becomes small. Therefore, it is possible to prevent the optical cable core from being poorly connected or the power cable core from being broken, and the damage to the cable 100 can be reduced.

  Moreover, it is preferable that the 1st coating | coated part 500 is comprised with a rigid large (strong) material. The first covering portion 500 is made of metal, for example.

(Second covering part (outer covering part))
As shown in FIGS. 1 and 2, a second covering portion (outer covering portion) 600 is fitted to the outside of the first covering portion 500. As shown in FIG. 3, in the present embodiment, the second covering portion 600 is divided along the axial direction of the cable 100. Moreover, the 2nd coating | coated part 600 is divided | segmented so that it may become symmetrical centering on the central axis of the 2nd cable insertion hole 610 mentioned later. Let the 2nd coating | coated part 600 divided | segmented into these 2 be 2nd coating | coated part 600a, 600b. The second covering portion 600 is easily fitted to the first covering portion 500 by joining the second covering portions 600a and 600b divided into two.

  As shown in FIGS. 1 and 2, a bolt insertion hole (not shown) is provided on the side surface of the second covering portion 600 that overlaps the first covering portion 500. Bolts 620 are inserted into the bolt insertion holes of the second covering portion 600. The bolt 620 is screwed into a screw hole 554 provided on the side surface of the first covering portion 500. Thereby, the 2nd coating | coated part 600 is fixed in the state fitted to the outer side of the 1st coating | coated part 500. FIG.

  Similar to the first covering portion 500, the second covering portion 600 has, for example, a truncated cone shape. The outer diameter of the second covering portion 600 on the cable connecting portion 20 side is equal to, for example, the diameter of the protective tube 330 or the diameter of the flange portion 400 of the cable connecting portion 20. Moreover, the outer diameter of the 2nd coating | coated part 600 is so small that it approaches the diameter of the cable 100 toward the other side from the cable connection part 20 side. Thereby, the level | step difference from the cable connection part 20 through the 1st coating | coated part 500 to the edge part on the opposite side to the cable connection part 20 of the 2nd coating | coated part 600 is relieve | moderated.

  A second cable insertion hole 610 into which the cable 100 is inserted is provided in the second covering portion 600 along the axial direction of the cable 100. The second cable insertion hole 610 is disposed so as to overlap the first cable insertion hole 510 when viewed from the axial direction of the cable 100. Unlike the first cable insertion hole 510, the second cable insertion hole 610 has a constant diameter from the cable connecting portion 20 side to the opposite side.

  Further, the second covering portion 600 has an elastic modulus smaller than that of the first covering portion 500. For example, the second covering portion 600 is made of rubber such as ethylene propylene rubber. Specifically, the elastic modulus of the second covering portion 600 is, for example, not less than 0.1 MPa and not more than 10 MP. In addition, the elasticity modulus of the 1st coating | coated part 500 which consists of metals is 10 GPa or more.

  Thus, the cable 100 is covered by the first covering portion 500 having high rigidity on the cable connecting portion 20 side, and is covered by the second covering portion 600 having low rigidity on the side opposite to the cable connecting portion 20. The rigidity of the submarine cable connection structure 10 gradually decreases in the axial direction of the cable 100 from the cable connection portion 20 side toward the opposite side. As a result, when the cable 100 is laid or when a force for bending the cable 100 is applied, the force for bending the cable 100 is concentrated at the end of the cable connecting portion 20 in the axial direction of the cable 100. Is suppressed, and the cable 100 bends gently from the cable connection portion 20 side toward the opposite side. Therefore, it is possible to suppress a phenomenon (corner breakage) in which the cable 100 is bent at the end of the cable connecting portion 20 in the axial direction of the cable 100.

  Further, when the cable 100 is laid or when a force to bend the cable 100 is applied after the cable 100 is laid, the second covering portion 600 bends to cause an elastic force to return to the cable 100. This action also suppresses the occurrence of a phenomenon in which the cable 100 is bent (corner breakage) at the end of the cable connecting portion 20 in the axial direction of the cable 100.

(Other)
A covering layer 700 is provided so as to cover the flange portion 400 and the second covering portion 600. The covering layer 700 is, for example, a cloth tape or a self-bonding tape. Thereby, the flange part 400, the 1st coating | coated part 500, and the 2nd coating | coated part 600 are firmly fixed to the edge part of the axial direction of the cable 100 of the cable connection part 20. FIG.

(Specific dimensions, etc.)
For example, the diameter of the cable 100 connected in the cable connection part 20 is 60 mm or more and 150 mm or less. The length of the cable connecting portion 20 in the axial direction of the cable 100 is not less than 3000 mm and not more than 5000 mm, and the diameter of the cable connecting portion 20 is not less than 200 mm and not more than 500 mm.

  Further, for example, the length of the first covering portion 500 in the axial direction of the cable 100 is not less than 300 mm and not more than 1000 mm. The curvature radius of the R-shaped portion 520 of the first covering portion 500 is not less than 600 mm and not more than 1500 mm. The axial length of the cable 100 of the second covering portion 600 is not less than 1000 mm and not more than 5000 mm.

(2) Submarine cable connection method Next, a submarine cable connection method according to the present embodiment will be described.

(First covering part insertion process)
The flange part 400 and the 1st coating | coated part 500 are prepared beforehand as follows. The first covering portion 500 is fixed to the flange portion 400 by inserting the bolt 540 into the bolt insertion hole of the plate-like portion 420 of the flange portion 400 and screwing it into the screw hole 552 of the first covering portion 500. Next, the cable 100 is inserted through the flange portion cable insertion hole 412 of the flange portion 400 and the first cable insertion hole 510 of the first covering portion 500.

(Cable connection process)
Next, the protective tube 330 constituting the cable connecting portion 20 is passed through one cable 100.

  The respective ends of the two cables 100 are peeled off stepwise from the anticorrosion layer 140 side. Next, the power cable core connection part 210 is formed by connecting the ends of the two power cable cores 110. Moreover, the optical cable core connection part 220 is formed by connecting the ends of the two optical cable cores 120.

  Next, the portion of the armor 130 of the cable 100 that has been peeled off in stages is sandwiched between a wedge-shaped cotter 312 that bends the iron wire along the outside and a disk-shaped fixing plate (a metal fitting) 310. Fix it. Further, the fixing plate 310 fixed to the one cable 100 is connected to the fixing plate 310 fixed to the other cable 100 via the connection fitting 320. Further, the protective tube 330 is disposed so as to surround the fixing plate 310, the cotter 312, the coupling metal 320, the power cable core connection portion 210, and the optical cable core connection portion 220, and the axial end of the cable 100 of the protection tube 330 is arranged. The fixing plate 310 and the cotter 312 are fixed inside the side. The protective tube 330 may be filled with the waterproofing mixture 340 so that the space between the fixing plate 310, the cotter 312, the coupling fitting 320, the power cable core connection part 210 and the optical cable core connection part 220 is filled. .

  The cable connection part 20 is formed by the above.

(First covering part connecting step)
Next, the cylindrical portion 410 of the flange portion 400 to which the first covering portion 500 is coupled is fitted to the outside of the protective tube 330 of the cable connection portion 20. Further, by inserting the bolt 430 into the bolt insertion hole of the cylindrical portion 410 of the flange portion 400 and screwing it into the screw hole 332 of the cable connecting portion 20, the flange portion 400 is connected to the end of the cable connecting portion 20 in the axial direction of the cable 100. Secure to the part. In this way, in a state where the cable 100 is inserted into the first covering portion 500, the first covering portion 500 is coupled to the cable end portion in the axial direction of the cable via the flange portion 400. .

(Second covering portion connecting step)
Next, the second covering portions 600a and 600b divided into two parts are joined so as to surround the cable 100, so that the cable 100 is inserted into the second covering portion 600, and the first covering portion is formed. Fit outside 500. Further, the second covering portion 600 is fixed to the first covering portion 500 by inserting the bolt 620 into the bolt insertion hole of the second covering portion 600 and screwing it into the screw hole 554 of the first covering portion 500.

(Coating layer forming process)
Next, the covering layer 700 is formed by, for example, winding a self-bonding tape so as to cover the flange portion 400 and the second covering portion 600.

  As described above, the two cables 100 are connected to form the water bottom cable connection structure 10.

(3) Effects according to the present embodiment According to the present embodiment and its modifications, the following one or more effects are achieved.

(A) According to the present embodiment, the first covering portion 500 is connected to the end portion of the cable connecting portion 20 in the axial direction of the cable 100, and the cable 100 is inserted into the first covering portion 500. The outer diameter of the 1st coating | coated part 500 is so small that it approaches the diameter of the cable 100 toward the other side from the cable connection part 20 side. The second covering portion 600 is fitted to the outside of the first covering portion 500, and the cable 100 is inserted into the second covering portion 600. The outer diameter of the 2nd coating | coated part 600 is so small that it approaches the diameter of the cable 100 toward the opposite side from the cable connection part 20 side. Thereby, the level | step difference from the cable connection part 20 through the 1st coating | coated part 500 to the edge part on the opposite side to the cable connection part 20 of the 2nd coating | coated part 600 is relieve | moderated. Further, the second covering portion 600 has an elastic modulus smaller than that of the first covering portion 500. The rigidity of the bottom cable connection structure 10 gradually decreases in the axial direction of the cable 100 from the cable connection portion 20 side to the opposite side. Thereby, it can suppress that the phenomenon (corner bend | folding) which the cable 100 bends in the edge part of the axial direction of the cable 100 of the cable connection part 20 generate | occur | produces.

  Here, as a first comparative example, a case where the first covering portion 500 and the second covering portion 600 as in the present embodiment are not coupled to the cable connecting portion will be considered. In the cable connecting portion, the portions (the power cable core connecting portion 210 and the optical cable core connecting portion 220 in this embodiment) where the ends of the two cable cores facing in the axial direction are connected are covered with a protective tube or the like. Therefore, the outer diameter of the cable connection portion is larger than the diameter of the cable. In the first comparative example, a step is formed at the end of the cable connecting portion in the axial direction of the cable, and this step becomes a rigid inflection point. For this reason, when a cable bending force is applied when laying the cable or after the cable is laid, the cable bending force is concentrated at the cable axial end of the cable connecting portion, and the cable is broken ( There is a possibility that corner breakage may occur. When the phenomenon that the cable is broken (corner breakage) occurs, there is a possibility that the optical cable core becomes defective in conduction or the power cable core breaks.

  In the case of the first comparative example described above, when the water depth is 30 m or less, when the cable is installed from the laying ship, the diver monitors the cable installation state, Occurrence of a phenomenon that the cable is bent at the end portion in the axial direction of the cable (square breakage) is suppressed. However, in the case where the water depth is 30 m or more, it is difficult to suppress the phenomenon of cable breakage (corner breakage) by monitoring with a diver.

  Next, as a second comparative example, consider a case where only a covering portion made of metal such as the first covering portion 500 in the present embodiment is coupled to the cable connection portion. In the second comparative example, a rigid inflection point is formed at the end of the covering portion opposite to the cable connection portion. For this reason, there is a possibility that the cable breaks (corner breakage) at the end of the covering portion opposite to the cable connecting portion.

  Next, as a third comparative example, consider a case where only the covering portion made of rubber such as the second covering portion 600 in the present embodiment is coupled to the cable connecting portion. In the third comparative example, the rigidity of the covering portion is insufficient, and the difference between the rigidity of the cable connecting portion and the rigidity of the covering portion is large. For this reason, the phenomenon that the cable 100 bends at the end of the cable connecting portion in the axial direction of the cable (that is, the joint portion between the cable connecting portion and the covering portion) is generated by bending the covering portion itself at a right angle. there's a possibility that.

  On the other hand, according to the present embodiment, the outer diameter of each of the first covering portion 500 and the second covering portion 600 is small so as to approach the diameter of the cable 100 from the cable connecting portion 20 side toward the opposite side. It has become. The level difference from the cable connecting part 20 to the end of the second covering part 600 opposite to the cable connecting part 20 via the first covering part 500 is alleviated. Further, the cable 100 is covered by the first covering portion 500 having high rigidity on the cable connecting portion 20 side, and is covered by the second covering portion 600 having low rigidity on the side opposite to the cable connecting portion 20. The rigidity of the submarine cable connection structure 10 gradually decreases in the axial direction of the cable 100 from the cable connection portion 20 side toward the opposite side. As a result, when the cable 100 is laid or when a force for bending the cable 100 is applied, the force for bending the cable 100 is concentrated at the end of the cable connecting portion 20 in the axial direction of the cable 100. Is suppressed, and the cable 100 bends gently from the cable connection portion 20 side toward the opposite side. Therefore, it is possible to suppress the phenomenon (corner breakage) that the cable 100 is bent at the end of the cable connecting portion 20 in the axial direction of the cable 100. Moreover, since the phenomenon that the cable 100 is broken is suppressed in advance, it is not necessary to perform monitoring by a diver. Thereby, the labor cost can be reduced, the cost when laying the cable 100 can be reduced, and the cable 100 can be laid stably even if the water depth is 30 m or more.

(B) According to this embodiment, the cable 100 to which the submarine cable connection structure 10 is applied is a power optical composite cable, and includes a power cable core 110 and an optical cable core 120. When the cable 100 is an optical fiber composite power cable, since the cable connection portion 20 includes the power cable core connection portion 210 and the optical cable core connection portion 220, the diameter of the cable connection portion 20 is larger than the diameter of the cable 100. Tend to be. In this case, the difference in the rigidity of the cable connecting portion 20 with respect to the rigidity of the cable 100 is increased. For this reason, the probability that the phenomenon that the cable is bent (corner breakage) occurs at the end of the cable connecting portion 20 in the axial direction of the cable 100 is increased. Therefore, it is particularly effective to apply the submarine cable connection structure 10 configured so that the rigidity is changed in stages to the cable 100 that is an optical fiber composite power cable as in the present embodiment.

(C) According to this embodiment, the 1st cable insertion hole 510 has spread toward the opposite side from the cable connection part 20 side. When the cable 100 is laid or when a force for bending the cable 100 is applied after the cable 100 is laid, the cable 100 is gradually bent from the cable connecting portion 20 side toward the opposite side. Thereby, not only the phenomenon that the cable 100 bends (perpendicularly) at the end of the cable connection portion 20 in the axial direction of the cable 100 (square breakage) is suppressed, but also the cable connection of the first covering portion 500. Occurrence of the phenomenon that the cable 100 is bent (at a right angle) at the end opposite to the portion 20 (opening end of the first cable insertion hole 510) (square breakage) is suppressed. Further, the cable 100 is prevented from being damaged by the opening end of the first cable insertion hole 510.

(D) According to this embodiment, the 1st coating | coated part 500 is connected with the cable connection part 20 via the flange part 400 connected with the axial direction edge part of the cable 100 of the cable connection part 20. FIG. Thereby, the 1st coating | coated part 500 can be easily connected with the cable connection part 20. FIG.

(E) According to the present embodiment, the first covering portion 500 is fixed to the plate-like portion 420 of the flange portion 400 by the bolts 540 provided along the axial direction of the cable 100. Thereby, when a force is applied to the first covering portion 500 from a direction perpendicular to the axial direction of the cable 100, it is possible to prevent the first covering portion 500 from being detached from the flange portion 400.

(F) According to the present embodiment, the second covering portion 600 is divided along the axial direction of the cable 100. After the first covering portion 500 is connected to the cable connecting portion 20, the second covering portions 600 a and 600 b divided into two parts are joined so as to surround the cable 100, so that the inside of the second covering portion 600 is established. The cable 100 can be inserted. Thereby, after the 1st coating | coated part 500 is connected with the cable connection part 20, the 2nd coating | coated part 600 can be easily fitted and fixed to the 1st coating | coated part 500. FIG.

  For example, when the second covering portion 600 is made of rubber, the frictional force between the cable 100 and the second covering portion 600 increases, so that the cable 100 can be slid into the second cable insertion hole 610 of the second covering portion 600. It can be difficult. For this reason, when the 2nd coating | coated part 600 consists of rubber, the structure in which the 2nd coating | coated part is not divided | segmented is not suitable, and the method of letting the cable 100 pass to the 2nd coating | coated part 600 beforehand before a cable connection process is not suitable. there is a possibility. In this embodiment, after the 1st coating | coated part 500 is connected with the cable connection part 20, the 2nd cable insertion of the 2nd coating | coated part 600 is carried out by couple | bonding the 2nd coating | coated parts 600a and 600b divided | segmented into two. The second covering portion 600 can be connected to the first covering portion 500 without sliding the cable 100 in the hole 610. Therefore, this embodiment is particularly effective when the second covering portion 600 is made of rubber.

<Second Embodiment of the Present Invention>
A second embodiment of the present invention will be described with reference to FIG. FIG. 4 is an enlarged cross-sectional view of a part of the submarine cable connection structure according to the present embodiment.

  This embodiment is different from the first embodiment in the manner of connection of the second covering portion to the first covering portion. Hereinafter, only elements different from those of the first embodiment will be described, and elements substantially the same as those described in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

(1) Submarine cable connection structure As FIG. 4 shows, the 1st coating | coated part 502 has the recessed part 560 in the side surface. The concave portion 560 of the first covering portion 502 is provided so as to surround the side surface of the first covering portion 502 in the circumferential direction. In addition, the concave portion 560 of the first covering portion 502 has a side surface along a direction perpendicular to the axial direction of the cable 100. Note that the side surface of the recess 560 of the first covering portion 502 does not need to be provided in a direction strictly perpendicular to the axial direction of the cable 100, and may have a component in a direction perpendicular to the axial direction of the cable 100. .

  On the other hand, the second covering portion 602 includes a convex portion 640 that is provided on a surface (inner side surface) that is fitted to the first covering portion 500 and that fits into the concave portion 560 of the first covering portion 500. The convex portion 640 of the second covering portion 602 is provided so as to surround the surface of the second covering portion 602 on the side fitted to the first covering portion 500 in the circumferential direction. Further, the convex portion 640 of the second covering portion 602 has a side surface along a direction perpendicular to the axial direction of the cable 100. The side surface along the direction perpendicular to the axial direction of the cable 100 of the convex portion 640 of the second covering portion 602 is the side surface along the direction perpendicular to the axial direction of the cable 100 of the concave portion 560 of the first covering portion 502 described above. Abut.

(2) 2nd coating | coated part connection process The connection method of the bottom cable of this embodiment differs in the 2nd coating | coated part connection process from 1st Embodiment. In the second covering portion connecting step, the second covering portions 602a and 602b divided into two parts are joined, and the cable 100 is inserted inside the second covering portion 602, and outside the first covering portion 502. Fit. At this time, the convex portion 640 provided on the surface of the second covering portion 602 that is fitted to the first covering portion 502 is fitted into the concave portion 560 provided on the side surface of the first covering portion 502.

(3) Effects according to the present embodiment (a) According to the present embodiment, the first covering portion 502 has the concave portion 560 on the side surface, and the second covering portion 602 is fitted to the first covering portion 500. And a convex portion 640 that fits into the concave portion 560 of the first covering portion 500. By fitting the convex portion 640 of the second covering portion 602 into the concave portion 560 of the first covering portion 502, the second covering portion 602 can be firmly fixed to the first covering portion 502.

(B) According to this embodiment, the side surface along the direction perpendicular to the axial direction of the cable 100 of the convex portion 640 of the second covering portion 602 is in the axial direction of the cable 100 of the concave portion 560 of the first covering portion 502. It abuts the side surface along the vertical direction. Thereby, when the cable 100 is laid or when a force for bending the cable 100 is applied after the cable 100 is laid, the second covering portion 602 can be prevented from being displaced in the axial direction of the cable 100.

<Third embodiment of the present invention>
A third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is an enlarged cross-sectional view of a part of the submarine cable connection structure according to the present embodiment. FIG. 6 is a schematic diagram showing an external appearance when the submarine cable connection structure according to the present embodiment is disassembled.

  This embodiment is different from the first embodiment in that the first covering portion is divided. Hereinafter, only elements different from those of the first embodiment will be described, and elements substantially the same as those described in the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

(1) Submarine cable connection structure As shown in FIG. 6, the first covering portion 504 is divided along the axial direction of the cable 100. The first covering portion 504 is divided so as to be symmetric about the central axis of the first cable insertion hole 510. Let the 1st coating | coated part 504 divided | segmented into these 2 be 1st coating | coated part 504a, 504b.

  As shown in FIGS. 5 and 6, for example, two strip-shaped iron wire binders 570 are wound around the outer side of the first covering portion 504 along the circumferential direction. Thereby, the 1st coating | coated parts 504a and 504b are couple | bonded.

  Further, the flange portion 404 may be divided along the axial direction of the cable 100. In this case, the flange portion 404 is divided so as to be symmetric about the central axis of the flange portion cable insertion hole 412. The flange portion 404 divided into two parts is referred to as flange portions 404a and 404b.

(2) Submarine cable connection method In this embodiment, it is not necessary to perform the first covering portion insertion step of passing each of the two cables 100 through the flange portion 400 and the first covering portion 500 in advance. Done from the process.

(First covering part connecting step)
After the cable connecting step, each of the first covering portions 504a and 504b is fixed to each of the flange portions 404a and 404b with a bolt 540. Next, by connecting the flange portions 404a and 404b to which the first covering portions 504a and 504b are respectively connected so as to surround the cable 100, the cable 100 is inserted into the first covering portion 500, and To do. Further, the flange portion 404 is fixed to the end portion of the cable connecting portion 20 in the axial direction of the cable 100 by the bolt 430. Next, for example, by winding two iron wire binders 570 around the outer periphery of the first covering portions 504a and 504b, the first covering portions 504a and 504b are joined. As described above, the first covering portion 500 is coupled to the cable end portion in the axial direction of the cable via the flange portion 400.

  The subsequent steps are the same as in the first embodiment.

(3) Effects According to this Embodiment According to this embodiment, the first covering portion 504 is divided along the axial direction of the cable 100. After the cable connecting step, the first covering portions 500a and 500b divided into two parts are joined so as to surround the cable 100, so that the cable 100 is inserted into the first covering portion 500. Can do. Thereby, the 1st coating | coated part 500 can be easily connected to the axial edge part side of the cable connection part 20 after a cable connection process.

<Other Embodiments of the Present Invention>
As mentioned above, although embodiment and modification of this invention were described concretely, this invention is not limited to the above-mentioned embodiment and modification, and can be variously changed in the range which does not deviate from the summary.

  In the above-described embodiment, the case where the protective tube 330 is not divided has been described. However, the protective tube may be divided along the axial direction of the cable. In this case, the power cable core connection portion and the optical cable core connection portion are formed, the cable is fixed to the fixing plate and the cotter, and the two fixing plates are connected via the connecting metal fitting, and then the protective tube is combined. .

  Moreover, although the above-mentioned embodiment demonstrated the case where the 1st coating | coated part 500 was connected with the cable connection part 20 via the flange part 400, the 1st coating | coated part may be directly connected with the cable connection part. .

  Moreover, although the above-mentioned embodiment demonstrated the case where the 1st cable insertion hole 510 of the 1st coating | coated part 500 had the R-shaped part 520, a 1st coating | coated part spreads toward the opposite side from the cable connection part side. It may have a flat inclined surface.

  Further, in the second embodiment described above, the case where the second covering portion 600 is fixed to the first covering portion 500 by the bolt 620 is illustrated, but the convex portion of the second covering portion is fitted into the concave portion of the first covering portion. As long as the second covering portion is fixed to the first covering portion by combining, the bolt for fixing the second covering portion to the first covering portion may not be provided.

  Moreover, although the above-mentioned embodiment demonstrated the case where the 2nd coating | coated part 600 was divided | segmented along the axial direction of the cable 100, for example, a cable can be slid to the 2nd cable insertion hole of a 2nd coating | coated part. If possible, the second covering portion may not be divided.

DESCRIPTION OF SYMBOLS 10 Submarine cable connection structure 20 Cable connection part 100 Cable 110 Power cable core 120 Optical cable core 130 Armoring 140 Anticorrosion layer 210 Power cable core connection part 220 Optical cable core connection part 310 Fixing plate 312 Cotta 320 Connecting metal fitting 330 Protective tube 332 Screw hole 340 Waterproof mixture 400, 404, 404a, 404b Flange portion 410 Cylindrical portion 412 Flange portion cable insertion hole 420 Plate portion 420 Connection portion 430 Bolt 500, 502, 504, 504a, 504b First covering portion 510 First Cable insertion hole 520 R-shaped portion 540 Bolt 552, 554 Screw hole 560 Recessed portion 570 Iron wire binder 600 Second covering portion 600, 600a, 600b, 602, 602a, 602b Second covering portion 610 Second cable insertion hole 620 Bolt 6 0 protrusions 700 cover layer

Claims (13)

A cable connection for connecting two cables laid on the bottom of the water;
The cable connection portion is connected to the end portion side of the cable in the axial direction, the cables of the two cables are inserted therein, and the outer diameter from the cable connection portion side to the opposite side is the diameter of the cable. A first covering portion that is small to approach
The cable is inserted into the outside of the first covering portion, the cable is inserted therein, and the outer diameter decreases from the cable connecting portion side to the opposite side so as to approach the diameter of the cable. A second covering portion having an elastic modulus smaller than the elastic modulus of the covering portion;
A submarine cable connection structure characterized by comprising: The submarine cable connection structure according to claim 1, wherein the cable includes a power cable core and an optical cable core. The first covering portion has a cable insertion hole through which the cable is inserted,
The submarine cable connection structure according to claim 1 or 2, wherein the cable insertion hole extends from the cable connection portion side toward the opposite side. The cable insertion hole is provided in the opening side opposite to the cable connection portion and has an R shape in which a cross-sectional shape when viewed from a direction perpendicular to the axial direction of the cable is convex toward the axial side of the cable. The submarine cable connection structure according to claim 3, further comprising a shape portion. The submarine cable connection structure according to claim 4, wherein a radius of curvature of the R-shaped portion is equal to or greater than a minimum bending radius of the cable. A flange connected to the axial end of the cable of the cable connecting portion;
The submarine cable connection structure according to claim 1, wherein the first covering portion is connected to the cable connection portion via the flange portion. The flange portion has a plate-like portion provided along a direction perpendicular to the axial direction of the cable,
The submarine cable connection structure according to claim 6, wherein the first covering portion is fixed to the plate-like portion of the flange portion by a bolt provided along the axial direction of the cable. The said 2nd coating | coated part is divided | segmented along the axial direction of the said cable, The bottom cable connection structure of any one of Claims 1-7 characterized by the above-mentioned. The said 1st coating | coated part is divided | segmented along the axial direction of the said cable, The submarine cable connection structure of any one of Claims 1-8 characterized by the above-mentioned. The first covering portion has a recess on a side surface,
The said 2nd coating | coated part has a convex part provided in the surface of the side fitted to the said 1st coating | coated part, and fitted to the said recessed part, The one of Claims 1-9 characterized by the above-mentioned. Underwater cable connection structure. The bottom cable connection structure according to any one of claims 1 to 10, wherein an elastic modulus of the second covering portion is 0.1 MPa or more and 10 MP or less. A cable connecting portion for connecting two cables laid on the bottom of the water is connected to the axial end side of each of the two cables, the cable is inserted into the inside, and the opposite side from the cable connecting portion side A first covering portion whose outer diameter is reduced toward the diameter of the cable toward the
The cable is inserted into the outside of the first covering portion, the cable is inserted therein, and the outer diameter decreases from the cable connecting portion side to the opposite side so as to approach the diameter of the cable. A second covering portion having an elastic modulus smaller than the elastic modulus of the covering portion;
A structure for reinforcing a submarine cable connection portion, comprising: Forming a cable connecting portion by connecting two cables laid on the bottom of the water;
In a state where the cable is inserted through the first covering portion whose outer diameter is reduced so as to approach the diameter of each of the two cables from the cable connecting portion side to the opposite side, Connecting one covering portion to an end portion side of the cable connecting portion in the axial direction of the cable;
The cable has an outer diameter that decreases from the cable connecting portion side to the opposite side so as to approach the diameter of the cable, and has an elastic modulus smaller than that of the first covering portion. In a state where the second covering portion is fitted to the outside of the first covering portion,
A method of connecting a submarine cable, comprising:

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