Swaging device, swaging device set, and method for manufacturing connected power cables

Abstract

To stably reduce diameter of a metal pipe at a cable connection portion.SOLUTION: A swaging device includes a plurality of cylindrical rolls that rotates while contacting an outer peripheral surface of a metal pipe to be reduced in diameter and a support frame portion for supporting the plurality of rolls so as to surround the outer periphery of the metal tube. The support frame portion has a diameter adjusting portion capable of adjusting the relative location of the plurality of rolls in the radial direction of the metal tube relative to the central axis of the metal tube.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a swaging device, a swaging device set, and a method for manufacturing a concatenated power cable. [Background technology]

[0002] When manufacturing a power cable that will be laid over a long distance, multiple power cables may be connected in a factory to produce a linked power cable having a desired distance. The cable connection in this case is called a "factory joint (FJ)" (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-56039 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to stably reduce the diameter of a metal tube at a cable connection portion. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal pipe with respect to the central axis of the metal pipe. A swaging device is provided.

[0006] According to another aspect of the present disclosure, A first swaging device and a second swaging device are provided, Each of the first swaging device and the second swaging device is a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with each of the support frames has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; the support frame of the first swaging device supports the plurality of rolls such that the axes of the plurality of rolls are oriented in a first direction inclined with respect to the axis of the metal tube; The support frame of the second swaging device supports the plurality of rolls between the first swaging device and the second swaging device so that the axes of the plurality of rolls face in a second direction opposite to the first direction across a cross section perpendicular to the axis of the metal tube. A swaging device set is provided.

[0007] According to yet another aspect of the present disclosure, providing a plurality of power cables; forming at least one cable connection portion by connecting a pair of power cables among the plurality of power cables; Equipped with the step of forming the cable connection portion includes a step of forming a metal tube made of metal so as to cover an outer periphery of each cable core of the pair of power cables, The step of forming the metal tube includes a step of reducing the diameter of the metal tube by using a swaging device to fit the outer periphery of the cable core, The swaging device includes: a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal pipe with respect to the central axis of the metal pipe. Using the device A method for manufacturing a concatenated power cable is provided. [Effects of the Invention]

[0008] According to the present disclosure, the diameter of the metal tube at the cable connection portion can be stably reduced. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a cable connection portion according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic enlarged view of the tip portion of the power cable in FIG. [Figure 3] FIG. 3 is a schematic enlarged view of the welded portion of the metal pipe in FIG. [Figure 4] FIG. 4 is a schematic diagram illustrating a swaging apparatus according to one embodiment of the present disclosure. [Figure 5] FIG. 5 is a cross-sectional view of the swaging device as seen in the direction of the dashed arrow in FIG. [Figure 6] FIG. 6 is a flowchart illustrating a method for manufacturing a linked power cable according to one embodiment of the present disclosure. [Figure 7] FIG. 7 is a flowchart showing the metal pipe forming process. [Figure 8] FIG. 8 is a schematic diagram showing the conductor connecting step. [Figure 9] FIG. 9 is a schematic diagram showing the cross-linking process. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Description of the embodiments of the present disclosure] <Knowledge gained by the inventors> First, the findings of the inventors will be explained.

[0011] (i) Knowledge about cable connections As mentioned above, an example of a power cable that is laid over a long distance is a submarine cable (underwater cable). The power cables that make up a submarine cable can only be manufactured to a finite length based on the manufacturing capacity of the factory. For this reason, as mentioned above, a linked power cable of the required length is manufactured as a submarine cable by connecting multiple power cables in the factory. The linked power cable is then loaded onto a cable laying ship.

[0012] Such a connecting power cable is subjected to bending stress during winding onto a turntable, transportation, extension, installation, etc. Therefore, the connecting power cable is required to have, for example, flexibility, and therefore it is desirable that the outer diameter of the cable connection part is approximately the same as the outer diameter of the power cable.

[0013] Furthermore, the connecting power cable is subjected to tensile forces during extension and installation, or when a current occurs after installation. For this reason, the connecting power cable is required to have, for example, tensile strength. Therefore, it is desirable that the connection strength between the power cables at the cable connection section be high.

[0014] Furthermore, when the interconnected power cable is laid on the seabed, for example, water may enter the cable joint, causing corrosion of the conductors, etc. For this reason, the interconnected power cable is required to be, for example, water-resistant (waterproof), and therefore, high sealing performance is desired at the cable joint.

[0015] (ii) Knowledge about the metal pipes that make up the cable joints In the cable joint described above, the conductors of a pair of power cables are connected together after being stripped in stages, so each layer of the cable joint must be formed to fit the complex outer shape of the inner layer.

[0016] For example, the diameter of the metal tube at the cable connection portion needs to be reduced to match the outer shape of the connected cable core.

[0017] If the diameter of the metal pipe is insufficient, a gap will form between the metal pipe and the cable core. This gap will increase the outer diameter of the cable connection. Furthermore, if water penetrates the metal pipe, it may be more likely to propagate in the axial direction of the power cable through the gap inside the metal pipe. Furthermore, the gap between the metal pipe and the cable core may become weak when laying the connecting power cable.

[0018] Therefore, there has been a demand for a swaging device that can stably reduce the diameter of a metal tube at a cable connection portion.

[0019] The present disclosure is based on the above findings (i) and (ii) made by the present inventors.

[0020] <Embodiments of the present disclosure> Next, embodiments of the present disclosure will be listed and described.

[0021] [1] A swaging device according to one aspect of the present disclosure includes: a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal pipe with respect to the central axis of the metal pipe. According to this configuration, it is possible to stably reduce the diameter of the metal tube at the cable connection portion.

[0022] [2] In the swaging device described in [1] above, The support frame supports the rolls so that the axes of the rolls are oriented in a direction inclined with respect to the axis of the metal tube. According to this configuration, the diameter of the metal pipe can be reduced in a spiral manner.

[0023] [3] In the swaging device according to the above [1] or [2], The support frame portion is a set support unit that supports a pair of rolls among the plurality of rolls in parallel with each other; a contact angle adjusting unit in the set support unit that can adjust a contact angle at which the pair of rolls contact the outer peripheral surface of the metal pipe; It has. According to this configuration, the pair of rolls 610 can be brought into stable contact with the outer peripheral surface of the metal in accordance with changes in the diameter of the metal pipe.

[0024] [4] A swaging device set according to another aspect of the present disclosure includes: A first swaging device and a second swaging device are provided, Each of the first swaging device and the second swaging device is a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with each of the support frames has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; the support frame of the first swaging device supports the plurality of rolls such that the axes of the plurality of rolls are oriented in a first direction inclined with respect to the axis of the metal tube; The support frame portion of the second swaging device supports the multiple rolls between the first swaging device and the second swaging device so that the axes of each of the multiple rolls face in a second direction opposite to the first direction, across a cross section perpendicular to the axis of the metal tube. According to this configuration, it is possible to stably reduce the diameter of the metal pipe at the cable connection portion while improving the smoothness of the outer peripheral surface of the metal pipe.

[0025] [5] A method for manufacturing a linked power cable according to yet another aspect of the present disclosure includes: providing a plurality of power cables; forming at least one cable connection portion by connecting a pair of power cables among the plurality of power cables; Equipped with the step of forming the cable connection portion includes a step of forming a metal tube made of metal so as to cover an outer periphery of each cable core of the pair of power cables, The step of forming the metal tube includes a step of reducing the diameter of the metal tube by using a swaging device to fit the outer periphery of the cable core, The swaging device includes: a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal pipe with respect to the central axis of the metal pipe. Use the device. According to this configuration, it is possible to stably reduce the diameter of the metal tube at the cable connection portion.

[0026] [Details of the embodiments of the present disclosure] Next, an embodiment of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0027] <One embodiment of the present disclosure> (1) Connecting power cables and cable connections A coupled power cable 10 and a cable connection portion (cable connection structure) 20 according to an embodiment of the present disclosure will be described with reference to Figs. 1 to 3. Fig. 1 is a schematic cross-sectional view showing the cable connection portion according to the present embodiment. Fig. 2 is a schematic enlarged view of the tip portion of the power cable in Fig. 1. Fig. 3 is a schematic enlarged view of the welded portion of the metal pipe in Fig. 1.

[0028] In Fig. 1, the side of the power cable 100 is shown after being stripped in stages. Since Figs. 1 to 3 are merely schematic diagrams, the thickness, spacing, shape, etc. of each part shown in each figure may differ from the actual shape. In addition, the lower side of each of Figs. 1 to 3 is omitted.

[0029] As shown in FIG. 1, the connecting power cable 10 of this embodiment is configured as an underwater cable laid on the bottom of the water (ocean bottom), and includes a plurality of power cables 100 and at least one cable connection part 20.

[0030] In the following, the "axial direction" of the power cable 100 or the like refers to the direction along the central axis of the power cable 100 or the like, and can be rephrased as the longitudinal direction of the power cable 100 or the like. The "radial direction" of the power cable 100 or the like refers to the direction perpendicular to the axial direction of the power cable 100 or the like, and can be rephrased as the lateral direction of the power cable 100 or the like in some cases. The "circumferential direction" of the power cable 100 or the like refers to the direction along the outer periphery of the power cable 100 or the like.

[0031] [Power cable] The power cable 100 is configured as a solid insulated cable (CE cable: Crosslinked polyethylene (PE) insulated PE sheathed cable, also called an XLPE cable) which is a high-voltage power transmission cable.

[0032] The power cable 100 has, for example, from the central axis side to the outer periphery, a conductor 110, a cable inner semiconductive layer 120, a cable insulating layer 130, a cable outer semiconductive layer 140, a water absorbing layer (not shown), a cable metal tube 150, and a cable sheath 160. Note that the portion of the power cable 100 from the conductor 110 to the cable outer semiconductive layer 140 is sometimes referred to as the "cable core."

[0033] The conductor 110 has, for example, a plurality of conductor strand layers 114 formed by helically twisting together a plurality of conductor strands 112. The conductor strands 112 are made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy.

[0034] The power cable 100 is stripped in stages from the tip of the conductor 110 to the opposite side (so-called "stage stripping"). That is, the conductor 110, the cable inner semiconductive layer 120, the cable insulating layer 130, the cable outer semiconductive layer 140, the cable metal pipe 150, and the cable sheath 160 are exposed in this order from the tip side of the conductor 110 to the opposite side. Hereinafter, each stage-stripped portion may be referred to as an "exposed portion." With this configuration, power cables 100 can be connected to each other in order from the central axis side to the outer periphery side.

[0035] The conductor 110, the cable inner semiconductive layer 120, the cable insulating layer 130, the cable outer semiconductive layer 140, and the cable metal tube 150 are cut obliquely with respect to the axis of the conductor 110. In other words, the power cable 100 is processed into, for example, a pencil shape, and has a conical peeled surface (reference numeral not shown) whose diameter expands from the tip of the conductor 110 toward the opposite side.

[0036] 2, the cable insulating layer 130 has a peeled surface that is inclined at a predetermined taper angle θ with respect to the axis of the conductor 110. The taper angle θ of the peeled surface of the cable insulating layer 130 is, for example, 5.2° or more and 8.6° or less with respect to the axis of the conductor 110. Setting the taper angle θ to 5.2° or more can prevent the length of the cable connection portion 20 in the axial direction of the conductor 110 from becoming excessively long. On the other hand, setting the taper angle θ to 8.6° or less can alleviate the electric field around the exposed cable insulating layer 130 while ensuring workability.

[0037] As shown in Fig. 1, a plurality of power cables 100 are provided. Of the plurality of power cables 100, a pair of power cables 100 are butted together with the axes of their conductors 110 aligned. In the following, one power cable 100 of the pair of power cables 100 may be referred to as a "first power cable 100a," and the other power cable 100 may be referred to as a "second power cable 100b."

[0038] [Cable connection] As shown in FIG. 1, the cable connection portion 20 includes, for example, a conductor connection portion 210, an inner semiconductive layer 220, an insulating layer 230, an outer semiconductive layer 240, a water-absorbing tape layer 242, a metal tube (protective tube) 250, and a corrosion-resistant layer (connection portion sheath) 260.

[0039] (conductor connection part) The conductors 110 of the pair of power cables 100 are connected at the conductor connection portion 210. The point at which the pair of conductors 110 are connected is also referred to as a "connection point." The conductor connection portion 210 has, for example, exposed portions (reference numerals not shown) of the pair of conductors 110 and a welded portion 212.

[0040] In the welded portion 212 of the conductor connecting portion 210 of this embodiment, for example, the conductors 110 are directly welded to each other without a metal tube (so-called conductor sleeve) being provided around the outer periphery of the conductors 110. In the welded portion 212, as described below, a plurality of conductor wires 112 are welded to each of a plurality of conductor wire layers 114 of the conductor 110. Furthermore, the conductor connecting portion 210 is compressed, for example, in the radial direction of the conductor 110. With this configuration, the outer diameter of the conductor connecting portion 210 is approximately equal to the outer diameter of the conductor 110 of the power cable 100.

[0041] (internal semiconductive layer) 1 and 2, the internal semiconductive layer 220 is provided so as to cover the outer periphery of the conductor connection portion 210. The internal semiconductive layer 220 has semiconductivity, which can alleviate electric field concentration near the surface of the conductor connection portion 210.

[0042] In this embodiment, the internal semiconductive layer 220 is formed, for example, by a semiconductive tape wrapped around the outer periphery of the conductor connection portion 210. The semiconductive tape is, for example, a cloth tape such as nylon or Tetron (registered trademark) coated with semiconductive rubber, or a tape made of a semiconductive resin material similar to that of the cable internal semiconductive layer 120 of the power cable 100 and containing a crosslinking agent, and is crosslinked by a crosslinking process described below. By forming the internal semiconductive layer 220 from such a semiconductive tape, the internal semiconductive layer 220 can be formed to match the outer shape and length of the conductor connection portion 210.

[0043] (insulating layer) 1, the insulating layer 230 is provided so as to cover the outer periphery of the internal semiconductive layer 220. The insulating layer 230 has insulating properties, thereby ensuring insulation on the outside of the conductor connection portion 210.

[0044] In this embodiment, the insulating layer 230 covers, for example, the inner semiconducting layer 220 and the exposed portion of the cable insulating layer 130. The insulating layer 230 has, for example, a conical surface whose diameter increases from the end of the insulating layer 230 toward the center in the axial direction of the conductor 110.

[0045] In this embodiment, the insulating layer 230 is formed, for example, by an insulating tape wrapped around the outer periphery of the exposed portions of the internal semiconductive layer 220 and the cable insulating layer 130. The insulating tape is, for example, a tape made of the same insulating resin material as the cable insulating layer 130 of the power cable 100 and containing a cross-linking agent, and is cross-linked by a cross-linking process described below. By forming the insulating layer 230 using such an insulating tape, the insulating layer 230 can be formed to fit the complex outer shapes of the internal semiconductive layer 220 and the exposed portions of the cable insulating layer 130.

[0046] (Outer semiconductive layer) 1, the outer semiconductive layer 240 is provided so as to cover the outer periphery of the insulating layer 230. The outer semiconductive layer 240 has semiconductivity, which makes it possible to reduce electric field concentration near the outside of the insulating layer 230.

[0047] In this embodiment, the outer semiconductive layer 240 is formed, for example, by a semiconductive tube that covers the outer periphery of the cable insulating layer 130. Examples of materials for the semiconductive tube include resin materials containing carbon black and the like. The semiconductive tube is heat-shrinkable. The semiconductive tube is cross-linked during manufacturing using a method such as electron beam irradiation, and is fused and integrated with the insulating layer in a cross-linking process described below. By forming the outer semiconductive layer 240 using such a semiconductive tube, the surface of the outer semiconductive layer 240 can be made smooth, even if the layers inside the outer semiconductive layer 240 are formed of tape.

[0048] In this embodiment, the outer semiconductive layer 240 covers the outer periphery of the insulating layer 230 and is in contact with the exposed end of the cable outer semiconductive layer 140. This makes the outer semiconductive layer 240 and the cable outer semiconductive layer 140 electrically equipotential.

[0049] (Water-absorbing tape layer) 1, the water-absorbing tape layer 242 is preferably provided so as to cover the outer periphery of the outer semiconductive layer 240, i.e., provided between the outer semiconductive layer 240 and the metal pipe 250 described below. The water-absorbing tape layer 242 has a similar structure to the water-absorbing layer of the power cable 100, and is, for example, a tape made of a polyester base fabric coated with semiconductive rubber and to which a water-absorbing polymer is attached. By providing such a water-absorbing tape layer 242, it is possible to suppress the propagation of water (i.e., water running) even if water penetrates into the metal pipe 250.

[0050] (metal tube) As shown in Fig. 1, the metal tube 250 is provided so as to cover the outer periphery of the outer semiconductive layer 240 (water-absorbing tape layer 242). The metal tube 250 is made of a rigid metal. Examples of metals that form the metal tube 250 include lead and aluminum. By providing such a metal tube 250, the impact resistance of the cable connection part 20 can be improved.

[0051] In this embodiment, the metal tube 250 is narrowed so as to contact the outer circumferential surface of the layer located inside the metal tube 250 (i.e., the water-absorbent tape layer 242). Therefore, the metal tube 250 has, for example, traces of narrowing. With this configuration, the outermost diameter of the cable connection part 20 can be reduced.

[0052] The metal tube 250 is reduced in diameter using a swaging device 60, which will be described later in detail.

[0053] 3, the axial end of the metal pipe 250 and the axial end of the cable metal pipe 150 are welded by a welded portion 252. This prevents water from seeping in between the metal pipe 250 and the cable metal pipe 150, and makes them electrically equipotential.

[0054] In addition, in this embodiment, it is preferable that a heat insulating portion 244 having heat insulating properties is provided between the welded portion 252 and the outer semiconductive layer 240. This makes it possible to suppress thermal deterioration of the cable core when the welded portion 252 is welded.

[0055] Furthermore, in this embodiment, a reinforcing portion 254 is provided so as to cover the outer periphery of the welded portion 252. Specifically, the reinforcing portion 254 has, for example, epoxy resin, glass tape soaked in epoxy resin, and adhesive PET (Polyethylene Terephthalate) tape covering these. This makes it possible to suppress the occurrence of cracks at the end of the welded portion 252.

[0056] (Anti-corrosion layer) As shown in Fig. 1, the anticorrosion layer 260 is provided to cover the outer periphery of the metal pipe 250 and the exposed portion of the cable metal pipe 150. The anticorrosion layer 260 is made of a resin having anticorrosive properties. Examples of anticorrosive resins include polyethylene blends. This can suppress corrosion of the cable core.

[0057] In this embodiment, the anticorrosion layer 260 is configured, for example, by a tube that covers the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. The tube of the anticorrosion layer 260 can easily cover the outer periphery of the metal pipe 250. In addition, the outer periphery surface of the anticorrosion layer 260 can be made smooth.

[0058] The anticorrosion layer 260 covers part of the outer periphery of the cable sheath 160, and therefore has a bulge 260a on the outer periphery of the cable sheath 160. The bulge 260a can stably prevent water from entering the cable core.

[0059] In this embodiment, the anticorrosion layer 260 may be provided in multiple layers in the radial direction of the conductor 110. This can improve the anticorrosion properties and reliability of the anticorrosion layer 260.

[0060] Specifically, the first corrosion protection layer 262 is provided so as to cover the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. The first corrosion protection part 263 is provided so as to cover the step between the axial end of the first corrosion protection layer 262 and the cable sheath 160. The first corrosion protection part 263 is made of, for example, a heated and melted polyethylene (PE) tape.

[0061] Furthermore, the second corrosion protection layer 264 is provided so as to cover the outer periphery of the first corrosion protection layer 262, the first corrosion protection portion 263, and part of the outer periphery of the cable sheath 160. The second corrosion protection portion 265 is provided so as to cover the step between the axial end of the second corrosion protection layer 264 and the cable sheath 160. The second corrosion protection portion 265 is made of, for example, a heated and melted PE tape.

[0062] With this configuration, the corrosion resistance and reliability of the corrosion protection layer 260 can be improved.

[0063] 1, in this embodiment, a filling portion 256 is preferably provided so as to fill the step between the exposed portion of the cable metal pipe 150 and the cable sheath 160. The filling portion 256 is made of, for example, an adhesive PE tape and an adhesive PET tape. This allows the anticorrosion layer 260 to smoothly cover the area between the exposed portion of the cable metal pipe 150 and the cable sheath 160.

[0064] (Cover part) In this embodiment, a cover portion 270 is preferably provided so as to cover the axial end portion (second corrosion protection portion 265) of the corrosion protection layer 260. The cover portion 270 is made of, for example, an adhesive PE tape and an adhesive PET tape. This makes it possible to smooth out any irregularities near the axial end portion of the corrosion protection layer 260.

[0065] (others) In this embodiment, the connecting power cable 10 preferably has a mark indicating the position of the cable connection part 20. The mark is configured, for example, by colored tape attached to the outer peripheral surface of the power cable 100 or the cable connection part 20. The mark may also be configured as a pattern printed or applied on the outer peripheral surface of the power cable 100. The mark may be located at either end or the center of the cable connection part 20. This allows the position of the cable connection part 20 to be easily recognized visually.

[0066] (Specific dimensions, etc.) The outermost diameter of the cable connection part 20 in this embodiment is, for example, approximately equal to the outermost diameter of the power cable 100. Specifically, the outermost diameter of the corrosion protection layer 260 in a cross section that includes the conductor connection part 210 and is perpendicular to the axis of the power cable 100 is, for example, +5 mm to +15 mm greater than the outermost diameter of the power cable 100.

[0067] In this embodiment, the outermost diameter of the cable connection part 20 is suppressed even at the position where the bulge 260a of the anticorrosion layer 260 is formed. Specifically, the outermost diameter in a cross section perpendicular to the axis of the power cable 100 and including the bulge 260a is, for example, +5 mm to +20 mm greater than the outermost diameter of the power cable 100.

[0068] (2) Swaging device Next, a swaging device 60 according to this embodiment will be described with reference to Fig. 4 and Fig. 5. Fig. 4 is a schematic diagram showing a swaging device according to one embodiment of the present disclosure. Fig. 5 is a cross-sectional view of the swaging device as seen in the direction of the dashed arrow in Fig. 4.

[0069] In the swaging device 60, the "axis of the metal tube 250" refers to the central axis of the metal tube 250 to be reduced in diameter, and can be rephrased as "the axis of the center of arrangement of the metal tube 250 in the swaging device 60." The "axial direction of the metal tube 250" refers to the direction along the central axis of the metal tube 250 to be reduced in diameter, and can be rephrased as "the extension direction of the metal tube 250 arranged in the swaging device 60" or "the insertion direction of the metal tube 250 in the swaging device 60." Furthermore, the "radial direction of the metal tube 250" refers to the direction perpendicular to the axial direction of the metal tube 250 to be reduced in diameter, and can be rephrased as the short-side direction of the metal tube 250 in some cases. Furthermore, the "circumferential direction of the metal tube 250" refers to the direction along the outer periphery of the metal tube 250 to be reduced in diameter.

[0070] The swaging device 60 according to this embodiment is configured to reduce the diameter of the metal tube 250, for example, by rotating a plurality of rolls 610 in the circumferential direction of the metal tube 250 and moving the positions of the plurality of rolls 610 closer to the central axis of the metal tube 250.

[0071] As shown in FIGS. 4 and 5, the swaging device 60 of this embodiment includes, for example, a plurality of rolls 610, a support frame portion 620, and a handle portion 660. [roll] As shown in FIGS. 4 and 5, each of the rolls 610 is configured to rotate while contacting the outer circumferential surface of the metal tube 250 to be reduced in diameter.

[0072] Each of the rolls 610 is configured, for example, as a long cylinder in its axial direction. The roll 610 has, for example, a ball bearing structure in which a cylindrical portion rotates around an axis via a plurality of balls.

[0073] The roll 610 is made of a metal that can withstand a diameter-reducing force, such as stainless steel.

[0074] In this embodiment, for example, eight rolls 610 are provided in one swaging device 60.

[0075] [Support frame] As shown in FIGS. 4 and 5, the support frame 620 is configured to support a plurality of rolls 610 so as to surround the outer periphery of the metal tube 250 to be reduced in diameter, for example.

[0076] The support frame 620 is made of a metal that can withstand a diameter-reducing force, similar to the roll 610. The metal that constitutes the support frame 620 is, for example, stainless steel.

[0077] 5, in this embodiment, the support frame 620 supports the multiple rolls 610 so that the axes of the multiple rolls 610 are oriented in a direction inclined with respect to the axis of the metal tube 250. This allows the diameter of the metal tube 250 to be reduced in a spiral manner.

[0078] Specifically, the support frame portion 620 has, for example, a set support portion 622, an outer frame portion 626, a diameter adjustment portion 640, and a contact angle adjustment portion 624.

[0079] (Set support part) The set support unit 622 is configured to support, for example, the pair of rolls 610 so that they can rotate around the circumferential direction of their respective axes. The set support unit 622 supports, for example, the pair of rolls 610 so that the axes of the pair of rolls 610 are parallel to each other and inclined with respect to the axis of the metal tube 250. Furthermore, the set support unit 622 supports, for example, the pair of rolls 610 at a distance apart so that they do not interfere with each other.

[0080] In this embodiment, for example, four set supports 622 are provided. When viewed in the axial direction of the metal tube 250 placed in the swaging device 60, the four set supports 622 are arranged at predetermined intervals around the metal tube 250 and are configured symmetrically with respect to the axis of the metal tube 250.

[0081] (Outer frame) The outer frame portion 626 is configured to support the set support portion 622. Specifically, the outer frame portion 626 has a support shaft provided near an end of the outer frame portion 626 along the axial direction of the roll 610, and the set support portion 622 is supported by the support shaft so as to be rotatable in the circumferential direction of the support shaft.

[0082] The outer frame portion 626 is configured, for example, in a C-shape so that the side on which the metal pipe 250 is placed is recessed. The outer frame portion 626 houses, for example, a pair of set support portions 622 inside the C-shape, and supports the pair of set support portions 622 by a pair of support shafts provided near both ends of the outer frame portion 626, respectively.

[0083] In this embodiment, a pair of outer frame portions 626 are provided. The pair of outer frame portions 626 are configured symmetrically with respect to the central axis of the metal tube 250 when viewed, for example, in the axial direction of the metal tube 250 placed in the swaging device 60. The pair of outer frame portions 626 support a total of four set support portions 622, that is, eight rolls 610.

[0084] The pair of outer frame portions 626 will be referred to as "outer frame portions 626a, 626b."

[0085] (diameter adjustment part) As shown in Figures 4 and 5, the diameter adjustment unit 640 is configured to be able to adjust the relative positions of multiple rolls 610 along the radial direction of the metal tube 250 with respect to the central axis of the metal tube 250 to be reduced in diameter.

[0086] Furthermore, for example, a pair of diameter adjustment parts 640 are provided. The pair of diameter adjustment parts 640 are provided at positions where the ends of the pair of outer frame parts 626 face each other, and connect the pair of outer frame parts 626 so that the distance between the pair of outer frame parts 626 can be adjusted.

[0087] Specifically, each diameter adjustment portion 640 has, for example, a threaded shaft 642 and a long nut 644 .

[0088] For example, in diameter adjustment section 640 provided at a first end (lower side in the figure) of outer frame section 626a, threaded shaft 642 is threadedly engaged with and fixed to the first end of outer frame section 626a, and is loosely inserted through an end of outer frame section 626b that faces the first end of outer frame section 626a. Long nut 644 is threadedly engaged with threaded shaft 642 at the end of outer frame section 626b. By threading long nut 644 provided on the outer frame section 626b side toward outer frame section 626a on threaded shaft 642, it is possible to push the end of outer frame section 626b with long nut 644, and bring the end of outer frame section 626b closer to the first end of outer frame section 626a.

[0089] On the other hand, for example, the diameter adjustment part 640 provided at the second end (upper side in the figure) of the outer frame part 626a is configured symmetrically to the diameter adjustment part 640 provided at the first end of the outer frame part 626a across the axis of the arrangement center of the metal pipe 250. By threading the long nut 644 provided on the outer frame part 626a side toward the outer frame part 626b on the screw shaft 642, the second end of the outer frame part 626a can be brought closer to the end part of the outer frame part 626b.

[0090] With this configuration, it is possible to adjust the relative positions of the multiple rolls 610 along the radial direction of the metal tube 250 with respect to the central axis of the metal tube 250 to be reduced in diameter. That is, it is possible to reduce the diameter of the metal tube 250 by moving the multiple rolls 610 supported by the pair of outer frame portions 626 closer to the central axis of the metal tube 250.

[0091] (Contact angle adjustment part) The contact angle adjusting unit 624 is configured to be able to adjust the contact angle α at which the pair of rolls 610 contact the outer circumferential surface of the metal tube 250 in the set support unit 622, for example. The "contact angle α" here refers to the angle between the normal to the plane formed by the axes of the pair of parallel rolls 610 and the radial direction of the metal tube 250.

[0092] As shown in FIG. 4, for example, it is preferable that the contact angle α is set to 0° so that the normal to the plane formed by the axes of a pair of parallel rolls 610 faces the radial direction of the metal tube 250.

[0093] By adjusting the contact angle α in this way, the pair of rolls 610 can be brought into stable contact with the outer circumferential surface of the metal tube 250 in accordance with changes in the diameter of the metal tube 250 .

[0094] Specifically, the contact angle adjustment unit 624 has, for example, a thumbscrew portion 624a and a push plate portion 624b. The thumbscrew portion 624a is disposed, for example, at the center of the outer frame portion 626 and is screwed into the outer frame portion 626. The push plate portion 624b is disposed, for example, at the tip of the thumbscrew portion 624a inside the outer frame portion 626. The push plate portion 624b is configured to push the pair of set support portions 622 toward the axis of the center of arrangement of the metal tube 250 by threading the thumbscrew portion 624a. With this configuration, the pair of set support portions 622 can each be rotated in the circumferential direction of the support axis. As a result, it is possible to adjust the contact angle α at which the pair of rolls 610 contact the outer circumferential surface of the metal tube 250.

[0095] [Handle] 4, the handle portion 660 is configured to be grippable by, for example, an operator. The handle portion 660 is configured, for example, in a rod shape, and is provided so as to extend outward from the outer frame portion 626. The operator can reduce the diameter of the metal tube 250 by rotating the swaging device 60 in the circumferential direction of the metal tube 250 while gripping the handle portion 660.

[0096] For example, a pair of handle portions 660 are provided. The pair of handle portions 660 are connected to the outer frame portions 626a and 626b, respectively.

[0097] The position of the handle portion 660 is not limited, but it is preferable that the handle portion 660 be provided in a position that does not interfere with, for example, the diameter adjustment portion 640 and the abutment angle adjustment portion 624. Specifically, it is preferable that the handle portion 660 be connected to, for example, the vicinity of the end of each of the outer frame portions 626a, 626b where the long nut 644 of the diameter adjustment portion 640 is not provided.

[0098] (3) Swaging device set Next, the swaging device set 62 according to this embodiment will be described with reference to FIG.

[0099] 5, in this embodiment, it is preferable to use a pair of swaging devices 60 as a set. Hereinafter, the set of the pair of swaging devices 60 will be referred to as a "swaging device set 62," and the pair of swaging devices 60 will be referred to as a "first swaging device 60a" and a "second swaging device 60b."

[0100] The first swaging device 60a and the second swaging device 60b have, for example, the same configuration as described above, except that the axial directions of the rolls 610 supported by each device are different.

[0101] Specifically, the support frame 620 of the first swaging device 60a supports the multiple rolls 610 so that the axes of each of the multiple rolls 610 face in a first direction inclined with respect to the axis of the metal tube 250, as described above.

[0102] On the other hand, the support frame 620 of the second swaging device 60b supports the multiple rolls 610 so that the axes of the multiple rolls 610 face in a second direction opposite to the first direction, across a cross section CS perpendicular to the axis of the metal tube 250, between the first swaging device 60a and the second swaging device 60b. The second swaging device 60b is preferably configured symmetrically to the first swaging device 60a, across the cross section CS perpendicular to the axis of the metal tube 250, between the first swaging device 60a and the second swaging device 60b.

[0103] With this configuration, streaky marks on the outer circumferential surface of the metal tube 250 caused by diameter reduction in the first swaging device 60a can be smoothly corrected (flattened or canceled) by the second swaging device 60b, which has a different arrangement of rolls 610. The opposite relationship is also possible in the same way as described above. As a result, the smoothness of the outer circumferential surface of the metal tube 250 can be improved.

[0104] The distance between the first swaging device 60a and the second swaging device 60b is not limited. The first swaging device 60a and the second swaging device 60b may be separated by a predetermined distance, or the first swaging device 60a and the second swaging device 60b may be in contact with each other.

[0105] (4) Manufacturing method of linked power cables (cable connection method) Next, a method for manufacturing a linked power cable according to this embodiment will be described with reference to Figs. 1 to 9. Fig. 6 is a flowchart showing the method for manufacturing a linked power cable according to this embodiment. Fig. 7 is a flowchart showing a metal pipe forming step. Note that steps are abbreviated as "S". Fig. 8 is a schematic diagram showing a conductor connecting step. Fig. 9 is a schematic diagram showing a bridging step.

[0106] As shown in FIG. 6, the method for manufacturing the linking power cable 10 of this embodiment includes, for example, a preparation step S100 and a cable connection step S200.

[0107] [S100: Preparation process] First, a plurality of power cables 100 are prepared.

[0108] Specifically, the power cable 100 is peeled in stages from the tip of the conductor 110 toward the opposite side. At this time, the power cable 100 is processed into a pencil shape, and a conical peeled surface is formed that expands in diameter from the tip of the conductor 110 toward the opposite side.

[0109] 2, the cable insulating layer 130 has a peeled surface that is inclined at a predetermined taper angle θ with respect to the axis of the conductor 110. The taper angle θ of the peeled surface of the cable insulating layer 130 is set to, for example, 5.2° or more and 8.6° or less.

[0110] After the step stripping of each of the pair of power cables 100 is completed, the first power cable 100a is inserted into, for example, the semiconductive tube that constitutes the outer semiconductive layer 240, the group of pressure tubes used in the second cross-linking step S244, the metal tube 250, and the tube that constitutes the corrosion protection layer 260.

[0111] Next, the power cable 100 is straightened (so-called "direct laying" is performed). Specifically, a ribbon heater is wrapped around the conductor 110, the cable-internal semiconductive layer 120, the cable insulating layer 130, and the exposed portions of the cable-external semiconductive layer 140, and heated to a predetermined temperature for a predetermined time. Once heating is complete, the ribbon heater and other components are removed. Next, the exposed portions of the conductor 110, the cable-internal semiconductive layer 120, the cable insulating layer 130, and the cable-external semiconductive layer 140 are fixed along a long L-shaped steel beam. In this state, the exposed portions of the conductor 110, the cable-internal semiconductive layer 120, the cable insulating layer 130, and the cable-external semiconductive layer 140 are cooled. This allows the power cable 100 to be straightened.

[0112] [S200: Cable connection process] After the preparation step S100 is completed, the cable connection step S200 is performed. The cable connection step S200 includes, for example, a conductor connection step S210, an inner semiconductive layer formation step S220, a first cross-linking step S224, an insulating layer formation step S230, an outer semiconductive layer formation step S240, a second cross-linking step S244, an inspection step S250, a metal pipe formation step S260, a corrosion protection layer formation step S270, and a post-treatment step S280.

[0113] (S210: Conductor connection process) A conductor connection section 210 is formed by connecting the conductors 110 of the pair of power cables 100 together.

[0114] 8, a ring 320 is fitted around the outer periphery of the outermost conductor wire layer 114f that constitutes the conductor 110. The ring 320 is also used for cooling during welding. After fitting the ring 320, the conductor wires 112 that constitute the conductor wire layer 114f are bent along the outer shape of the ring 320.

[0115] The same procedure as for the conductor wire layer 114f is repeated for each of the conductor wire layers 114e to 114c. After that, only the central conductor wire layers 114a and 114b are left straight. The tips of the straight conductor wire layers 114a and 114b are cut into a cone shape (tapered).

[0116] Once the bending of the conductor wire layer 114 and other processes are complete, the air nozzle 310 is positioned toward the exposed portion of the conductor 110. The conductors 110 of the pair of power cables 100 are butted together in a straight line with a predetermined gap between them.

[0117] Next, the conductor wire layers 114 are welded together in the following manner: The conductors 110 can be welded together by gas welding using propane gas and oxygen gas, for example.

[0118] First, the straight conductor wire layers 114a and 114b of the pair of power cables 100 are welded together. During and after welding, cooling air is supplied to the conductor 110 from the air nozzle 310 to cool the welded portion of the conductor wire layers 114a and 114b. The cooling method may be a method in which cooling water is passed through a cooling water flow path formed inside the ring 320. After cooling, the welded portion of the conductor wire layers 114a and 114b is shaped using a belt sander and sandpaper.

[0119] Next, the bent conductor wires 112 of the conductor wire layer 114c are returned to their straight states, and the ring 320 used to bend the conductor wire layer 114c is removed. At this time, the conductor wire layer 114c is shaped using a jig or the like. After shaping, the conductor wires 112 of the conductor wire layers 114c of the pair of power cables 100 are welded together. After welding, the welded portions of the conductor wires 112 of the conductor wire layer 114c are cooled. If the finished outer diameter does not satisfy the specifications after cooling, the conductor wire layers 114c to 114a are shaped appropriately using a jig.

[0120] The same procedure as that for welding the conductor wire layer 114c is repeated in turn for each of the conductor wire layers 114d to 114f, thus forming the conductor connection portion 210.

[0121] Thereafter, a predetermined conductor compression device or compression tool is used to compress and shape the conductor connection portion 210. By compression molding, the outer diameter of the conductor connection portion 210 is made approximately equal to the outer diameter of the conductor 110 of the power cable 100, and any bends in the conductor connection portion 210 are corrected.

[0122] As a result, all of the conductor wires 112 welded at the conductor connection portion 210 become one body.

[0123] (S220: Internal semiconducting layer formation process) After the conductor connecting step S210, an internal semiconductive layer 220 having semiconductivity is formed so as to cover the outer periphery of the conductor connecting portion 210.

[0124] Specifically, the pair of power cables 100 are pulled in opposite directions to maintain a straight line. In this state, a semiconductive tape is wound around the conductor connection portion 210 to cover the outer periphery of the conductor connection portion 210. This forms the inner semiconductive layer 220.

[0125] (S224: 1st crosslinking step) After the internal semiconductive layer forming step S220, in this embodiment, the internal semiconductive layer 220 is crosslinked.

[0126] Specifically, a group of pressure tapes is wrapped around the exposed portions of the inner semiconductive layer 220, the cable inner semiconductive layer 120, the cable insulating layer 130, and the cable outer semiconductive layer 140. A thermocouple, aluminum foil, and a heater are then attached, and the heating area is heated to a predetermined temperature for a predetermined time. This crosslinks the inner semiconductive layer 220. Once crosslinking is complete, the heater and the group of pressure tapes are sequentially removed. After crosslinking is complete, the surfaces of the inner semiconductive layer 220, the cable inner semiconductive layer 120, the cable insulating layer 130, and the cable outer semiconductive layer 140 are scraped to achieve the specified outer diameter.

[0127] (S230: Insulation layer formation process) After the first cross-linking step S224, an insulating layer 230 having insulating properties is formed so as to cover the outer periphery of the internal semiconductive layer 220. Specifically, insulating tape is wound by hand or using a taping device in a clean booth kept clean so as to cover the internal semiconductive layer 220 and the exposed portion of the cable insulating layer 130. In this way, the insulating layer 230 is formed.

[0128] (S240: Outer semiconducting layer formation process) After the insulating layer forming step S230, an outer semiconductive layer 240 having semiconductivity is formed so as to cover the outer periphery of the insulating layer 230.

[0129] Specifically, a semiconductive tube that has been previously passed through the first power cable 100a is placed on the outer periphery of the cable insulating layer 130. After the semiconductive tube is placed, it is heat-shrunk. The excess length of the semiconductive tube is then cut off. This forms the outer semiconductive layer 240 so as to cover the outer periphery of the insulating layer 230 and to contact the exposed end of the cable outer semiconductive layer 140.

[0130] (S244: 2nd crosslinking step) After the outer semiconductive layer forming step S240, the cable core is heated to crosslink the insulating layer 230 and fuse the inner semiconductive layer 220, the insulating layer 230 and the outer semiconductive layer 240 together to form an integrated body.

[0131] First, the outer periphery of the outer semiconductive layer 240 is covered with a presser tube and a group of presser tapes.

[0132] Next, as shown in FIG. 9, the cable core covered with the presser tube group is set in a bridging device 50.

[0133] The cross-linking device 50 includes, for example, a heating furnace (mold furnace) 510, a heater 520, and a gas supply line 530. The heating furnace 510 is configured as a cylindrical body having a hollow portion into which a cable core is inserted. The heater 520 is provided in the heating furnace 510 and configured to heat the cable core in the hollow portion of the heating furnace 510. The gas supply line 530 is provided in the hollow portion of the heating furnace 510 along the axial direction of the heating furnace 510. The gas supply line 530 has the ability to fill and pressurize a gas such as nitrogen gas or air in the hollow portion of the heating furnace 510.

[0134] After the cable core is set in the cross-linking device 50, a gas such as nitrogen gas or air is supplied from a gas supply line 530 to the cable core in the hollow portion of the heating furnace 510 to pressurize it, while the cable core is heated by a heater 520. By heating the cable core for a predetermined time at a predetermined temperature and pressure, the insulating layer 230 is cross-linked.

[0135] After cross-linking, the cable core is removed from the cross-linking device 50. Next, the group of presser tubes that have been covering the cable core are removed.

[0136] (S250: Inspection process) After the second cross-linking step S244, the cable connection portion 20 is inspected by X-ray to check for the presence of foreign matter and to measure the insulation thickness.

[0137] (S260: Metal tube forming process) If it is confirmed in the inspection step S250 that there are no abnormalities, as shown in FIG. 1, a metal tube 250 made of metal is formed so as to cover the outer periphery of the outer semiconductive layer 240 as follows.

[0138] In this embodiment, as shown in FIG. 7, the metal pipe forming process S260 includes, for example, a water absorbing tape layer forming process S261, a heat insulating portion forming process S262, a swaging process S263, a welding process S264, a reinforcing portion forming process S265, and a filling portion forming process S266.

[0139] (S261: Water-absorbing tape layer forming process) First, a water-absorbing tape is wound around the outer periphery of the outer semiconductive layer 240 to cover it, thereby forming a water-absorbing tape layer 242.

[0140] (S262: Heat insulating part forming process) Next, as shown in FIG. 3, a heat insulating portion 244 having heat insulating properties is formed at a position directly below a welded portion 252, which will be described later.

[0141] After the heat insulating portion 244 is formed, the metal pipe 250 that has been passed through the first power cable 100 a in advance is moved, and the outer periphery of the outer semiconductive layer 240 is covered with the metal pipe 250 .

[0142] (S263: Swaging process) After the heat insulating portion 244 is formed, the metal pipe 250 that has been passed through the first power cable 100 a in advance is moved, and the outer periphery of the outer semiconductive layer 240 is covered with the metal pipe 250 .

[0143] After the metal tube 250 is placed, the above-mentioned swaging device 60 is used to reduce the diameter of the metal tube 250 so that it conforms to the outer periphery of the cable core, i.e., so that it contacts the outer periphery of the layer located inside the metal tube 250.

[0144] Specifically, as shown in Figures 4 and 5, an operator holds the handle portion 660 and rotates the swaging device 60 in the circumferential direction of the metal pipe 250, whereby the multiple rolls 610 in the swaging device 60 are rotated while being in contact with the outer peripheral surface of the metal pipe 250.

[0145] At this time, the diameter adjusting unit 640 of the support frame 620 adjusts the relative positions of the multiple rolls 610 along the radial direction of the metal tube 250 with respect to the central axis of the metal tube 250 to be reduced in diameter.

[0146] For example, the diameter adjusting unit 640 moves the multiple rolls 610 supported by the pair of outer frame portions 626 of the support frame portion 620 closer to the central axis of the metal tube 250, thereby reducing the diameter of the metal tube 250. Note that in the portion where the cable core has expanded in diameter relative to the reduced diameter metal tube 250, the diameter adjusting unit 640 may return the positions of the multiple rolls 610 outward from the central axis of the metal tube 250.

[0147] Furthermore, at this time, the support frame 620 supports the multiple rolls 610 so that the axes of the multiple rolls 610 are oriented in a direction inclined with respect to the axis of the metal tube 250. Therefore, as the swaging device 60 rotates in the circumferential direction of the metal tube 250, the multiple rolls 610 can be advanced in a spiral relative to the metal tube 250. That is, the multiple rolls 610 can advance in the axial direction of the metal tube 250 while reducing the diameter of the metal tube 250 in the radial direction. In this way, the diameter of the metal tube 250 can be reduced in a spiral manner.

[0148] At this time, the diameter of the metal tube 250 is reduced using a swaging device set 62 having a first swaging device 60a and a second swaging device 60b in which the inclination directions of rolls 610 are opposite to each other across a cross section CS perpendicular to the axis of the metal tube 250. This allows streaky marks on the outer peripheral surface of the metal tube 250 caused by the diameter reduction in the first swaging device 60a and the second swaging device 60b to be smoothly corrected.

[0149] Furthermore, at this time, for example, when the diameter of the metal pipe 250 changes, the contact angle adjusting unit 624 of each swaging device 60 adjusts the contact angle α at which the pair of rolls 610 contacts the outer peripheral surface of the metal pipe 250 in the set support unit 622. This allows the pair of rolls 610 to stably contact the outer peripheral surface of the metal pipe 250 in accordance with changes in the diameter of the metal pipe 250.

[0150] At this time, while the diameter of the metal tube 250 is being reduced by the swaging device 60, the swaging device 60 is moved back and forth multiple times in the axial direction of the metal tube 250. This allows the diameter of the metal tube 250 to be gradually reduced, thereby reducing damage to the metal tube 250 that accompanies the diameter reduction. Furthermore, by moving back and forth multiple times, streaky marks on the outer circumferential surface of the metal tube 250 that are caused by the above-mentioned diameter reduction can be gradually smoothed.

[0151] (S264: Welding process) 3, the axial end of the metal pipe 250 and the axial end of the cable metal pipe 150 are welded together at a welded portion 252. Examples of a method for welding the metal pipe 250 include gas welding using hydrogen gas and oxygen gas.

[0152] (S265: Reinforcement part forming process) After welding, a reinforcing portion 254 is formed to cover the outer periphery of the welded portion 252. Specifically, epoxy resin is applied to the outer periphery of the welded portion 252, and glass tape soaked in epoxy resin is wound around it. Furthermore, adhesive PET tape is wound around it to cover these. In this way, the reinforcing portion 254 is formed.

[0153] (S266: Filling part forming process) 1, an adhesive PE tape and an adhesive PET tape are wound in this order so as to fill in the step between the exposed portion of the cable metal tube 150 and the cable sheath 160. In this way, a filling portion 256 is formed.

[0154] (S270: Anti-corrosion layer formation process) After the metal pipe forming step S260, as shown in FIG. 1, a corrosion prevention layer 260 made of resin is formed so as to cover the outer periphery of the metal pipe 250 as follows.

[0155] First, a PE tube that has been passed through the first power cable 100a in advance is used to cover the outer periphery of the metal pipe 250, the exposed portion of the cable metal pipe 150, and part of the outer periphery of the cable sheath 160. After covering the metal pipe 250, the PE tube is thermally shrunk. This forms the first anticorrosion layer 262.

[0156] After the first corrosion protection layer 262 is formed, PE tape is wrapped around and heated to melt so as to cover the step between the axial end of the first corrosion protection layer 262 and the cable sheath 160, as shown in Fig. 1. This forms the first corrosion protection part 263.

[0157] Next, the PE tube that has been passed through the first power cable 100a in advance is used to cover the outer periphery of the first corrosion protection layer 262, the first corrosion protection portion 263, and part of the outer periphery of the cable sheath 160. After covering them, the PE tube is heat-shrunk. This forms the second corrosion protection layer 264.

[0158] After the second corrosion protection layer 264 is formed, PE tape is wrapped around and heated to melt so as to cover the step between the axial end of the second corrosion protection layer 264 and the cable sheath 160, as shown in Fig. 1. This forms the second corrosion protection part 265.

[0159] (S280: Post-processing process) After the anticorrosion layer forming step S270, the following post-treatments may be carried out as necessary.

[0160] 1, adhesive PE tape and adhesive PET tape are wound in this order to cover the axial end (second corrosion protection portion 265) of the corrosion protection layer 260. In this way, the cover portion 270 is formed.

[0161] In this manner, the linked power cable 10 of this embodiment is manufactured.

[0162] (5) Effects of this embodiment According to this embodiment, one or more of the following effects are achieved.

[0163] (a) In this embodiment, in the swaging device 60, multiple rolls 610 are rotated while being in contact with the outer circumferential surface of the metal tube 250. At this time, the diameter adjustment unit 640 of the support frame unit 620 adjusts the relative positions of the multiple rolls 610 along the radial direction of the metal tube 250 with respect to the central axis of the metal tube 250 to be reduced in diameter. The diameter adjustment unit 640 moves the multiple rolls 610 closer to the central axis of the metal tube 250, thereby reducing the diameter of the metal tube 250. This allows the metal tube 250 to be reduced in diameter in accordance with the outer periphery of the cable core, i.e., so as to come into contact with the outer circumferential surface of the layer located inside the metal tube 250.

[0164] By reducing the diameter of the metal pipe 250 so that it contacts the outer peripheral surface of the layer located inside the metal pipe 250, it is possible to suppress the occurrence of gaps between the metal pipe 250 and the cable core. This makes it possible to suppress an increase in the outermost diameter of the cable connection part 20 due to gaps between the metal pipe 250 and the cable core. Furthermore, by suppressing the occurrence of gaps between the metal pipe 250 and the cable core, it is possible to suppress the propagation of water in the axial direction of the power cable 100 through gaps in the metal pipe 250 when water enters the metal pipe 250. Furthermore, when laying a connected power cable 10 that suppresses the occurrence of gaps between the metal pipe 250 and the cable core, it is possible to suppress the formation of weak parts due to gaps between the metal pipe 250 and the cable core.

[0165] As described above, according to this embodiment, the diameter of the metal tube 250 in the cable connection portion 20 can be reduced stably.

[0166] (b) In this embodiment, the support frame 620 supports the multiple rolls 610 so that the axes of the multiple rolls 610 are oriented in a direction inclined relative to the axis of the metal tube 250. This allows the multiple rolls 610 to advance spirally relative to the metal tube 250 as the swaging device 60 rotates in the circumferential direction of the metal tube 250.

[0167] That is, the metal tube 250 can be reduced in the radial direction by the multiple rolls 610 while the multiple rolls 610 move in the axial direction of the metal tube 250. In other words, the multiple rolls 610 inclined with respect to the axis of the metal tube 250 can achieve both the reduction of the metal tube 250 in the radial direction and the movement of the rolls 610 in the axial direction of the metal tube 250 in a self-aligned manner.

[0168] In this way, the diameter of the metal tube 250 can be reduced in a spiral manner. As a result, the swaging step S263 using the swaging device 60 can be carried out smoothly and quickly.

[0169] (c) In this embodiment, a swaging device set 62 having a first swaging device 60a and a second swaging device 60b is used to reduce the diameter of the metal tube 250. A support frame 620 of the second swaging device 60b supports the multiple rolls 610 so that the axes of the multiple rolls 610 face in a second direction opposite to the first direction, across a cross section CS perpendicular to the axis of the metal tube 250, between the first swaging device 60a and the second swaging device 60b.

[0170] Here, when the diameter of the metal tube 250 is reduced using one swaging device 60 in which the axis of the roll 610 is inclined as described above, streak-like marks may remain on the outer peripheral surface of the metal tube 250 along the path of the spiral movement of the roll 610. If streak-like marks remain on the outer peripheral surface of the metal tube 250, the streak-like marks may become mechanically weak parts.

[0171] In contrast, in this embodiment, as described above, the first swaging device 60a and the second swaging device 60b are used, in which the inclination directions of the rolls 610 are opposite to each other across the cross section CS perpendicular to the axis of the metal tube 250. This allows the second swaging device 60b, which has a different arrangement of the rolls 610, to smoothly correct (flatten or cancel) the streaky marks on the outer surface of the metal tube 250 caused by diameter reduction in the first swaging device 60a. These opposite relationships are also possible, as described above. As a result, the smoothness of the outer surface of the metal tube 250 can be improved.

[0172] Improving the smoothness of the outer surface of the reduced diameter metal tube 250 makes it possible to suppress the formation of mechanically weak parts caused by streaky marks, thereby improving the shape stability and rigidity of the cable connection part 20.

[0173] (d) In this embodiment, the contact angle adjusting section 624 is configured to be able to adjust the contact angle α at which the pair of rolls 610 contacts the outer circumferential surface of the metal pipe 250 in the set support section 622 .

[0174] Here, when the diameter of the metal tube 250 is reduced while the support positions of the pair of rolls 610 are fixed, the contact angle α at which the pair of rolls 610 contact the outer circumferential surface of the metal tube 250 changes due to a change in the diameter of the metal tube 250. When the contact angle α changes, the distances of the pair of rolls 610 from the central axis of the metal tube 250 change. This may result in different diameter-reducing forces (pressing forces) in the pair of rolls 610.

[0175] In contrast, in this embodiment, by adjusting the contact angle α at which the pair of rolls 610 contact the outer peripheral surface of the metal tube 250, the pair of rolls 610 can be stably contacted with the outer peripheral surface of the metal tube 250 in accordance with changes in the diameter of the metal tube 250. In other words, the distances of the pair of rolls 610 from the central axis of the metal tube 250 can be made equal. This makes it possible to make the diameter-reducing force (pressing force) of each of the pair of rolls 610 equal. As a result, the diameter of the metal tube 250 can be reduced more stably.

[0176] <Other Embodiments of the Present Disclosure> Although the embodiments of the present disclosure have been specifically described above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present disclosure.

[0177] In the above embodiment, the case where the connecting power cable 10 is configured as an underwater cable has been described, but the connecting power cable 10 may also be configured to be laid underground or above ground.

[0178] In the above embodiment, the linking power cable 10 has one cable connection portion 20 , but the linking power cable 10 may have a plurality of cable connection portions 20 .

[0179] In the above embodiment, the conductors 110 are directly welded to each other at the conductor connection portion 210, but the conductors 110 may also be connected to each other by compressing a conductor sleeve that surrounds the outer periphery of the conductors 110 at the conductor connection portion 210. However, from the viewpoint of reducing the outer diameter of the conductor connection portion 210 and improving connection strength, it is preferable that the conductors 110 are directly welded to each other.

[0180] In the above-described embodiment, the case where the filling portion 256 is provided between the exposed portion of the cable metal tube 150 and the cable sheath 160 has been described, but the end of the cable sheath 160 may also be cut in a tapered shape.

[0181] In the above embodiment, the anticorrosion layer 260 is provided in a plurality of layers in the radial direction of the conductor 110, but the anticorrosion layer 260 may be a single layer as long as corrosion resistance can be ensured.

[0182] In the above embodiment, the anticorrosion layer 260 is made of a tube, but the anticorrosion layer 260 may be made of a tape. The anticorrosion layer 260 may be either insulating or semi-conductive.

[0183] <Preferred aspects of the present disclosure> Preferred aspects of the present disclosure are described below.

[0184] (Appendix 1) a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal pipe with respect to the central axis of the metal pipe. Swaging device.

[0185] (Appendix 2) the support frame portion has a pair of outer frame portions configured to support the plurality of rolls, respectively; The diameter adjusting portion is provided as a pair at positions where the ends of the pair of outer frame portions face each other, and connects the pair of outer frame portions so as to adjust the separation distance between the pair of outer frame portions. 2. The swaging device of claim 1.

[0186] (Appendix 3) The support frame supports the plurality of rolls such that the axes of the rolls are oriented in a direction inclined with respect to the axis of the metal tube. 10. The swaging device of claim 1 or 2.

[0187] (Appendix 4) The support frame portion is a set support unit that supports a pair of rolls among the plurality of rolls in parallel with each other; a contact angle adjusting unit in the set support unit that can adjust a contact angle at which the pair of rolls contact the outer peripheral surface of the metal pipe; have 4. The swaging device according to any one of claims 1 to 3.

[0188] (Appendix 5) the support frame portion has an outer frame portion configured to support the set support portion, The outer frame portion has a support shaft provided near an end of the outer frame portion along the axial direction of the roll, and is configured to support the set support portion rotatably in the circumferential direction of the support shaft by the support shaft. 5. The swaging device of claim 4.

[0189] (Appendix 6) A first swaging device and a second swaging device are provided, Each of the first swaging device and the second swaging device is a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with each of the support frames has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; the support frame of the first swaging device supports the plurality of rolls such that the axes of the plurality of rolls are oriented in a first direction inclined with respect to the axis of the metal tube; The support frame of the second swaging device supports the plurality of rolls between the first swaging device and the second swaging device so that the axes of the plurality of rolls face in a second direction opposite to the first direction across a cross section perpendicular to the axis of the metal tube. Swaging device set.

[0190] (Appendix 7) providing a plurality of power cables; forming at least one cable connection portion by connecting a pair of power cables among the plurality of power cables; Equipped with the step of forming the cable connection portion includes a step of forming a metal tube made of metal so as to cover an outer periphery of each cable core of the pair of power cables, The step of forming the metal tube includes a step of reducing the diameter of the metal tube by using a swaging device to fit the outer periphery of the cable core, The swaging device includes: a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal pipe with respect to the central axis of the metal pipe. Using the device Method for manufacturing interlocking power cables. [Explanation of symbols]

[0191] 10 Connecting power cable 20 Cable connection 50 Crosslinking equipment 60 Swaging device 60a First swaging device 60b Second swaging device 62 Swaging Device Set 100 Power Cable 100a First power cable 100b Second power cable 110 Conductor 112 Conductor wire 114(114a~114f) Conductor wire layer 120 Cable inner semiconductive layer 130 Cable insulation layer 140 Cable outer semiconductive layer 150 Cable Metal Tube 160 Cable sheath 210 Conductor connection 212 Welded parts 220 Internal semiconductive layer 230 Insulating layer 240 outer semiconductive layer 242 Water-absorbing tape layer 244 Insulation section 250 metal tube 252 Welded parts 254 Reinforcement 256 Filling section 260 Anti-corrosion layer 260a Bulge 262 First anti-corrosion layer 263 First Corrosion Prevention Department 264 Second anti-corrosion layer 265 Second Corrosion Prevention Department 270 Cover 310 Air Nozzle 320 Ring 510 Heating Furnace 520 Heater 530 Gas Supply Line 610 rolls 620 Support frame 622 Set support part 624 Contact angle adjustment part 624a Thumbscrew part 624b Push plate part 626(626a, 626b) Outer frame part 640 Diameter adjustment part 642 screw shaft 644 Long Nut 660 Handle

Claims

1. a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame portion is a diameter adjustment unit that adjusts the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; a set support unit that supports a pair of rolls among the plurality of rolls in parallel with each other; a contact angle adjusting unit in the set support unit that can adjust a contact angle at which the pair of rolls contact the outer peripheral surface of the metal pipe; have Swaging device.

2. The support frame supports the plurality of rolls such that the axes of the rolls are oriented in a direction inclined with respect to the axis of the metal tube.

2. The swaging device of claim 1.

3. A first swaging device and a second swaging device are provided, Each of the first swaging device and the second swaging device is a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube to be reduced in diameter; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with each of the support frames has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; the support frame of the first swaging device supports the plurality of rolls such that the axes of the plurality of rolls are oriented in a first direction inclined with respect to the axis of the metal tube; The support frame portion of the second swaging device supports the plurality of rolls between the first swaging device and the second swaging device so that the axes of the plurality of rolls are oriented in a second direction opposite to the first direction across a cross section perpendicular to the axis of the metal tube. Swaging device set.

4. providing a plurality of power cables; forming at least one cable connection portion connecting a pair of power cables among the plurality of power cables; Equipped with the step of forming the cable connection portion includes a step of forming a metal tube made of metal so as to cover an outer periphery of each cable core of the pair of power cables, The step of forming the metal tube includes a step of reducing the diameter of the metal tube by using a swaging device to fit the outer periphery of the cable core, The swaging device includes: a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with The support frame portion is a diameter adjustment unit that adjusts the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; a set support unit that supports a pair of rolls among the plurality of rolls in parallel with each other; a contact angle adjusting unit in the set support unit that can adjust a contact angle at which the pair of rolls contact the outer peripheral surface of the metal pipe; have Using the device Method for manufacturing interlocking power cables.

5. A step of preparing a plurality of power cables; forming at least one cable connection portion connecting a pair of power cables among the plurality of power cables; Equipped with the step of forming the cable connection portion includes a step of forming a metal tube made of metal so as to cover an outer periphery of each cable core of the pair of power cables, The step of forming the metal tube includes a step of reducing the diameter of the metal tube by using a swaging device set to conform to the outer periphery of the cable core, The swaging device set includes: A first swaging device and a second swaging device are provided, Each of the first swaging device and the second swaging device is a plurality of cylindrical rolls that rotate while contacting the outer peripheral surface of the metal tube; a support frame that supports the rolls so as to surround an outer periphery of the metal tube; Equipped with each of the support frames has a diameter adjustment portion that can adjust the relative positions of the plurality of rolls along the radial direction of the metal tube with respect to the central axis of the metal tube; the support frame of the first swaging device supports the plurality of rolls such that the axes of the plurality of rolls are oriented in a first direction inclined with respect to the axis of the metal tube; The support frame portion of the second swaging device supports the plurality of rolls between the first swaging device and the second swaging device so that the axes of the plurality of rolls are oriented in a second direction opposite to the first direction across a cross section perpendicular to the axis of the metal tube. Using Sets Method for manufacturing interlocking power cables.

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