Cable connection method, cable connection structure, and cable connection member

Abstract

To enhance reliability of connection, and to facilitate installation work of a cable connection structure.SOLUTION: The method includes a step of exposing the shielding layer 2j by stripping the cable sheath 2h and the water shielding layer 2j to separate the cable sheath 2h and the water shielding layer 2f from the shielding layer 2f, a step of fixing piercing terminals 40 attached to the ground wires 50 to portions 17 of the cable sheath 2j and the water shielding layer 2h separated from the shielding layer 2f by piercing the piercing terminals 40 into the portions 17, and a step of connecting the ground wires 50 extending from the piercing terminals 40 to the shielding layer in a bent state. 2j 2h 2f 2f.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a cable connection method, a cable connection structure, and a cable connection member. [Background technology]

[0002] Patent Document 1 describes a method for forming a joint of a plastic-insulated power cable with a water-shielding layer. In this method, when forming a joint of a plastic-insulated power cable having a water-shielding layer made of a metal laminate tape, which is made by laminating a plastic layer on a metal tape, under the plastic sheath, the end of the plastic sheath to which the water-shielding layer is adhered is cut into strips. The cut portion is folded back to expose the surface of the metal tape, and a metal ground wire is soldered to connect the ground wire electrically to the metal shielding layer of the cable.

[0003] Patent Document 2 describes a grounding structure for a power cable with a water-shielding layer. This grounding structure is for a power cable with a water-shielding layer, which has a cable water-shielding layer made of a metal laminate interposed between the cable sheath and the cable shielding layer. The grounding structure includes a grounding terminal connected to a ground wire and a fastener that electrically and mechanically connects the grounding terminal to the cable water-shielding layer. The fastener is composed of a single-threaded screw consisting of a first fastener and a second fastener. The first fastener is inserted into a through-hole that radially penetrates the cable sheath and the cable water-shielding layer from the cable water-shielding layer side, sandwiching the grounding terminal therebetween, and the second fastener is inserted into the through-hole from the cable sheath side and tightened to the first fastener, thereby fixing the grounding terminal to the cable water-shielding layer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 147905 / 1983 [Patent Document 2] Japanese Patent Application Publication No. 2019-122103 Summary of the Invention [Problem to be solved by the invention]

[0005] As mentioned above, when cutting a plastic sheath into strips and then folding back the cut sections to expose the metal tape surface and soldering a metal ground wire to it, there is a concern that the soldered connection may not be strong enough. That is, there is a concern that the strength of the soldered connection may decrease due to thermal expansion and contraction. Furthermore, since the reliability of the soldered connection depends on the skill of the worker performing the soldering, there is room for improvement in terms of connection reliability.

[0006] The above-mentioned grounding structure includes a grounding terminal connected to a grounding wire, a first fastener inserted into the through hole from the cable water shielding layer side, and a second fastener inserted into the through hole from the cable sheath side and fastened to the first fastener. In this grounding structure, a through hole is formed in the cable sheath and the cable water shielding layer, and the first fastener and second fastener are inserted into the through hole and fastened to the first fastener. As such, because the through hole is formed in the cable sheath and the cable water shielding layer in advance, there is room for improvement in the ease of installation of the cable connection structure. [Means for solving the problem]

[0007] The cable connection method according to the present disclosure is a cable connection method for a cable having a water-proof layer located inside a cable sheath and a shielding layer located inside the water-proof layer, and includes the steps of: exposing the shielding layer by peeling off the cable sheath and the water-proof layer to separate the cable sheath and the water-proof layer from the shielding layer; fixing a piercing terminal attached to a ground wire to the portion of the cable sheath and the water-proof layer spaced apart from the shielding layer by piercing the piercing terminal attached to the ground wire into the portion of the cable sheath and the water-proof layer spaced apart from the shielding layer; and connecting the ground wire extending from the piercing terminal to the shielding layer in a bent state.

[0008] In this cable connection method, the cable sheath and the water-shielding layer are stripped to expose the shielding layer located inside the cable sheath and the water-shielding layer, and a piercing terminal with a ground wire is pierced into the portion of the cable sheath and the water-shielding layer spaced from the shielding layer. Therefore, the ground wire extending from the piercing terminal is brought into contact with and fixed to the shielding layer, thereby electrically and mechanically connecting the water-shielding layer to the shielding layer. By electrically connecting the shielding layer to the water-shielding layer, the potential of the water-shielding layer and the potential of the shielding layer are equalized, thereby suppressing voltage induction. Therefore, discharge due to voltage induction can be suppressed. Furthermore, connecting the water-shielding layer and the shielding layer with the piercing terminal and the ground wire eliminates the need for soldering, thereby improving connection reliability. Since the piercing terminal can be pierced to connect the ground wire with the piercing terminal to the shielding layer, the number of parts can be reduced and the installation of the cable connection structure can be easily performed. Furthermore, since the ground wire is connected to the shielding layer in a bent state, even if thermal expansion or the like occurs, the bent portion can adapt to the thermal expansion or the like. Therefore, even if thermal expansion or the like occurs, the connection between the water shielding layer and the shielding layer can be maintained more reliably, thereby further improving the reliability of the connection.

[0009] The ground wire may be flat.

[0010] The ground wire may have a mesh pattern.

[0011] The cable connection method described above may include a step of winding a grounding spring around the ground wire extending from the bent portion along the shielding layer.

[0012] The length of the ground wire may be not less than 100 mm and not more than 200 mm.

[0013] The cross-sectional area of ​​the ground wire is 1.25 mm 2 Above 14mm 2 It may be the following:

[0014] The step of securing the piercing terminal may include securing a plurality of piercing terminals.

[0015] The piercing terminal may have blade portions that pierce the cable sheath and the water-shielding layer at a portion spaced from the shielding layer, and the number of blade portions may be two or more and ten or less.

[0016] The cable connection structure according to the present disclosure is a cable connection structure provided on a cable having a water-proof layer located inside a cable sheath and a shielding layer located inside the water-proof layer, and includes a ground wire and a piercing terminal attached to the ground wire and configured to pierce a portion of the cable sheath and the water-proof layer spaced apart from the shielding layer, and the ground wire is connected to the shielding layer in a bent state.

[0017] This cable connection structure is provided on a cable having a cable sheath, a water-proof layer, and a shielding layer, and the cable sheath and the water-proof layer have a portion spaced apart from the shielding layer. A piercing terminal with a ground wire is pierced into the spaced apart portion of the cable sheath and the water-proof layer. The ground wire extending from the piercing terminal is bent and connected to the shielding layer. Therefore, by contacting and fixing the ground wire extending from the bent portion to the shielding layer, the water-proof layer can be electrically and mechanically connected to the shielding layer. This makes it possible to equalize the potential of the water-proof layer and the potential of the shielding layer, suppressing voltage induction and preventing discharges associated with voltage induction. As with the cable connection method described above, the water-proof layer and the shielding layer are connected by the piercing terminal and the ground wire, eliminating the need for soldering and improving connection reliability. Because the piercing terminal can be pierced through the cable sheath and the ground wire to connect the ground wire to the shielding layer, the number of parts can be reduced and the installation of the cable connection structure can be easily performed. Since the ground wire is connected to the shielding layer in a bent state, even if thermal expansion or the like occurs, the bent portion can follow the thermal expansion, etc. Therefore, even if thermal expansion or the like occurs, the connection between the water shielding layer and the shielding layer can be more reliably maintained, thereby further improving the reliability of the connection.

[0018] A cable connection structure according to another aspect of the present disclosure includes a shielding layer ground wire drawn out from the shielding layer, the shielding layer ground wire having a first grounding drawer portion that connects to the shielding layer and a second grounding drawer portion that connects to a terminal at a position extending from the first grounding drawer portion in the longitudinal direction of the cable, the first grounding drawer portion being located inside a water-shielding layer-integrated tube that covers the cable, and the second grounding drawer portion being located outside the water-shielding layer-integrated tube, and including a grounding wire drawer protection portion that covers the second grounding drawer portion.

[0019] In this cable connection structure, the shielding layer ground wire has a first ground lead portion that connects to the shielding layer and a second ground lead portion that connects to a terminal at a position extending from the first ground lead portion in the cable longitudinal direction, and the first ground lead portion is provided inside the tube with a water-impermeable layer. This prevents the first ground lead portion from becoming uneven, thereby preventing wrinkles from forming in the water-impermeable layer of the tube with a water-impermeable layer. Furthermore, the second ground lead portion located outside the tube with a ground wire lead protector is covered, thereby protecting the second ground lead portion located outside the tube with a water-impermeable layer.

[0020] The cable connection member according to the present disclosure is a cable connection member attached to a cable having a water-proof layer located inside a cable sheath and a shielding layer located inside the water-proof layer, and includes a flat, mesh-like ground wire, a piercing terminal attached to the ground wire and configured to pierce a portion of the cable sheath and the water-proof layer spaced apart from the shielding layer, and a grounding spring wound around the ground wire extending along the shielding layer.

[0021] In this cable connection member, a piercing terminal with a ground wire is inserted into the cable sheath and the water-shielding layer at a portion spaced from the shielding layer. The ground wire extending from the piercing terminal is arranged to extend along the shielding layer. Therefore, by contacting and fixing the ground wire extending from the piercing terminal that penetrates the cable sheath and the water-shielding layer to the shielding layer, the water-shielding layer can be electrically and mechanically connected to the shielding layer. This allows the potential of the water-shielding layer to be equalized to the potential of the shielding layer, thereby suppressing voltage induction and discharge. Furthermore, this eliminates the need for soldering, improving connection reliability. Furthermore, since the piercing terminal penetrates the cable sheath and the ground wire to connect the ground wire to the shielding layer, the installation of the cable connection structure can be facilitated. In this cable connection member, the ground wire that contacts the shielding layer can be fixed by wrapping a grounding spring around it. Therefore, the reliability of the connection can be further improved without using solder. Furthermore, since the ground wire extending from the piercing terminal can be arranged in a bent state along the inside of the cable sheath and the water-shielding layer and along the shielding layer, even if thermal expansion or the like occurs, the bent portion can follow the thermal expansion, etc. Therefore, even if thermal expansion or the like occurs, the connection between the water-shielding layer and the shielding layer can be more reliably maintained, thereby further improving the reliability of the connection. [Effects of the Invention]

[0022] According to the present disclosure, it is possible to improve the reliability of the connection and facilitate the installation work of the cable connection structure. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing a cable connection structure according to an embodiment. [Figure 2] 1A is a schematic diagram of an inner cold-shrinkable tube according to an embodiment, and FIG. 1B is a cross-sectional view of an example of an inner cold-shrinkable tube according to an embodiment. [Figure 3]1A is a schematic diagram of an outer cold-shrinkable tube according to an embodiment, and FIG. 1B is a cross-sectional view of an example of an outer cold-shrinkable tube according to an embodiment. [Figure 4] 4A and 4B are diagrams illustrating an insulating tube of the cable connecting member according to the embodiment. [Figure 5] 1A and 1B are diagrams illustrating connectors of a cable connecting member according to an embodiment. [Figure 6] 1(a) and 1(b) are diagrams showing a cable connection structure according to an embodiment. [Figure 7] 1 is a cross-sectional view of an exemplary cable. [Figure 8] 1A and 1B are diagrams illustrating a piercing terminal and a ground wire of a cable connecting member according to an embodiment. [Figure 9] 1A is a diagram showing a piercing terminal of a cable connecting member according to an embodiment, FIG. 1B is a diagram showing a ground wire of a cable connecting member according to an embodiment, and FIG. 1C is a diagram showing a ground spring of a cable connecting member according to an embodiment. [Figure 10] 1A, 1B, and 1C are diagrams illustrating a procedure for a cable connecting method according to an embodiment. [Figure 11] 5A and 5B are diagrams illustrating a procedure for a cable connecting method according to an embodiment. [Figure 12] 5A and 5B are diagrams illustrating a procedure for a cable connecting method according to an embodiment. [Figure 13] 1A to 1C are diagrams illustrating steps of a cable connecting method according to an embodiment. [Figure 14] 1A to 1C are diagrams illustrating steps of a cable connecting method according to an embodiment. [Figure 15] 5A and 5B are diagrams illustrating a procedure for a cable connecting method according to an embodiment. [Figure 16] 10(a) and 10(b) are diagrams showing a cable connection structure according to a modified example. [Figure 17] 10A and 10B are diagrams illustrating a cable connection structure according to a modified example. [Figure 18] FIG. 2 is a diagram illustrating a shielding layer ground wire in a cable connection structure. [Figure 19] 10A and 10B are cross-sectional views showing examples of a first ground lead portion and a second ground lead portion of a shielding layer ground wire in a cable connection structure. [Figure 20] FIG. 4 is a side view schematically showing a first ground lead portion. [Figure 21] FIG. 3 is a side view schematically showing a first ground lead portion and a second ground lead portion. [Figure 22] 10 is a side view schematically showing a ground wire lead protection portion that covers the second ground lead portion. FIG. [Figure 23] 10 is a cross-sectional view showing a ground wire lead protection portion according to a modified example. FIG. [Figure 24] 10 is a cross-sectional view showing a ground wire lead protection portion according to a modified example. FIG. [Figure 25] 25 is a perspective view schematically showing a metal member of the second ground lead portion of FIG. 24. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the cable connection method, cable connection structure, and cable connection member according to the present disclosure will be described in detail with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations will be omitted as appropriate. Furthermore, the drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional proportions and the like are not limited to those shown in the drawings.

[0025] First, the term "cable" in this disclosure includes power cables such as CVT cables, insulated wires, and communication cables, and there are many different types of "cables." A "cable connection" includes a connection that connects multiple cables together and its surroundings, a connection that connects a cable to a connector and its surroundings, and a connection that connects a cable to a device other than a connector and its surroundings. The term "inside" in this disclosure refers to the conductor side of the cable in the member that covers the cable, i.e., the inside in the radial direction of the cable. The term "outside" refers to the opposite side of the conductor in the member that covers the cable (the cable sheath side), i.e., the outside in the radial direction of the cable.

[0026] In the embodiment, the cable comprises a cable sheath, a water-proof layer, and a shielding layer. "Cable sheath" refers to the outer covering (outer coating) of the cable. "Water-proof layer" refers to a layer that blocks moisture, including humidity. "Shielding layer" is a metal layer that is grounded, and is made of, for example, copper. A piercing terminal attached to a grounding wire penetrates the cable sheath and the water-proof layer. "Grounding wire" is wiring for connecting to ground. "Piercing terminal" refers to a terminal having a portion that penetrates the cable sheath, for example, having a claw portion that penetrates the cable sheath.

[0027] As shown in FIG. 1 , an exemplary cable connection structure 1 according to this embodiment includes a pair of cables 2, a cable connection portion 10 that connects the pair of cables 2 to each other, a pair of inner cold shrink tubes (inner pre-stretched tube, inner cold shrink PST tube) 20 that cover the cables 2, and a pair of outer cold shrink tubes (outer pre-stretched tube, outer cold shrink PST tube) 30 that cover the cable connection portion 10 and the inner cold shrink tube 20.

[0028] The cable 2 is, for example, a power cable rated at 66 kV. However, the cable 2 may also be a power cable rated at 66 kV or higher (for example, 77 kV or 154 kV). The cable 2 includes, for example, a conductor 2b, an insulating layer 2c covering the conductor 2b, a semiconductive layer 2d covering the insulating layer 2c, a shielding layer 2f covering the semiconductive layer 2d, a water-shielding layer 2h (see FIG. 7) laminated with a semiconductive layer 2g covering the shielding layer 2f, and a cable sheath 2j covering the water-shielding layer 2h. For example, the shielding layer 2f is a shielding copper tape. As an example, the cable connection part 10 includes a shielding processing part 16 at each end in the longitudinal direction D1 of the insulating tube 11, which will be described later. The shielding processing part 16 will be described in detail later.

[0029] The cross-sectional area of ​​the conductor 2b is, for example, 80 (mm 2 ) or more and 600 (mm 2 ) or less, and the outer diameter (diameter) of the cable connection part 10 is 90 mm or more. The outer diameter of the cable connection part 10 is, for example, larger than the outer diameter of the cable 2. The lower limit of the outer diameter of the cable connection part 10 may be 100 mm, 110 mm, 120 mm, or 130 mm. The upper limit of the outer diameter of the cable connection part 10 may be 200 mm, 170 mm, or 150 mm. For example, the outer diameter of the cable connection part 10 is 135 mm or more and 145 mm or less. However, the outer diameter of the cable connection part 10 is not limited to the above values ​​and is not particularly limited.

[0030] For example, the cable connection part 10 is provided at an end of a cable 2 and connects the ends of a pair of cables 2 to each other. As an example, one cable 2, the cable connection part 10, and the other cable 2 are arranged side by side along the longitudinal direction D1 of the cable connection structure 1. An exemplary cable connection member 100 includes an inner cold-shrinkable tube 20 that covers a portion adjacent to the cable connection part 10, an outer cold-shrinkable tube 30 that covers the cable connection part 10 and the inner cold-shrinkable tube 20, a piercing terminal 40 (see FIGS. 6(a) and 6(b)) that is fixed to the wound cable 2, a ground wire 50 extending from the piercing terminal 40, and a grounding spring 60 that is wound around the ground wire 50 and the shielding layer 2f.

[0031] FIG. 2(a) is a perspective view schematically illustrating an exemplary inner cold-shrinkable tube 20. FIG. 2(b) is a schematic cross-sectional view of the inner cold-shrinkable tube 20. As shown in FIGS. 2(a) and 2(b), the inner cold-shrinkable tube 20 may be expanded in diameter by a diameter expansion holding member 23. The diameter expansion holding member 23 has a disassembly line 23b formed in a direction in which the axis L1 of the diameter expansion holding member 23 extends (hereinafter also referred to as the axial direction). The diameter expansion holding member 23 is, for example, a cylindrical tubular hollow member. The disassembly line 23b is formed so as to gradually extend in the axial direction while going around the axis L1 of the diameter expansion holding member 23, or going around and reversing.

[0032] As an example of the material for the diameter expansion holding member 23, a resin material such as polyethylene or polypropylene is used. The diameter expansion holding member 23 can be pulled out as a string-like body, that is, core ribbon 23c, along the unraveling line 23b. The portion where the unraveling line 23b is formed is thinner than the surrounding area, making it more susceptible to breaking.

[0033] For example, the unwinding line is not limited to a spiral shape like the unwinding line 23b, but may be formed in an SZ shape, or may have any shape as long as it is retractable. When the core ribbon 23c is pulled, the diameter expansion holding member 23 breaks sequentially along the unwinding line 23b, and new core ribbons 23c are continuously pulled out. Because the unwinding line 23b is formed at a constant pitch, for example, the width of the pulled-out core ribbon 23c is constant. However, the width of the core ribbon 23c does not have to be constant.

[0034] The dismantling lines 23b may be formed only on the inner peripheral surface of the diameter expansion holding member 23, may be formed only on the outer peripheral surface of the diameter expansion holding member 23, or may be formed on both the inner peripheral surface and the outer peripheral surface of the diameter expansion holding member 23. The diameter expansion holding member 23 having the dismantling lines 23b may be manufactured, for example, by spirally winding the dismantling lines 23b and fixing adjacent dismantling lines 23b to each other by bonding, welding, engaging, or a combination thereof, or may be manufactured by directly forming the dismantling lines 23b on a cylindrical member.

[0035] The retractable tubular hollow diameter expansion holding member may be one in which the inner cold-shrinkable tube is gradually shrunk by pulling the core ribbon, as in the above-described diameter expansion holding member 23, or one in which the diameter expansion holding member slides relative to the inner cold-shrinkable tube and is pulled out from the inner cold-shrinkable tube, thereby detaching it. The diameter expansion holding member 23 has a first end 23d that is the starting end from which the core ribbon 23c is pulled out, and a second end 23f that is the terminal end from which the core ribbon 23c is pulled out. An exposed portion 23g is formed near the first end 23d, where the inner cold-shrinkable tube 20 is not attached and the outer circumferential surface of the diameter expansion holding member 23 is exposed, and another exposed portion 23g is formed near the second end 23f.

[0036] The core ribbon 23c unwound from the first end 23d is, for example, passed through the inside of the diameter expansion holding member 23 and pulled out from the second end 23f side. By pulling out the core ribbon 23c from the second end 23f side, the diameter expansion holding member 23 is sequentially unwound from the first end 23d toward the second end 23f. In this embodiment, the core ribbon 23c is formed over the entire length in the axial direction, so it is possible to completely unwound the diameter expansion holding member 23 from the first end 23d to the second end 23f. However, it is sufficient that the unwound line 23b is formed in at least the portion of the diameter expansion holding member 23 that expands and holds the inner cold-shrinkable tube 20; for example, there may be a portion in a predetermined region on the second end 23f side where the unwound line 23b is not formed.

[0037] As an example, the inner cold-shrinkable tube 20 is a member expanded and held on the outer periphery of the diameter expansion holding member 23. The inner cold-shrinkable tube 20 covers a portion of the cable 2 adjacent to the cable connection portion 10. The inner cold-shrinkable tube 20 is made of, for example, rubber that shrinks at room temperature and has excellent expansion and contraction properties. The inner cold-shrinkable tube 20 may be made of, for example, a waterproof material. Here, "waterproof" refers to a state in which the inner cold-shrinkable tube 20, when in a shrunk state, is capable of preventing liquid from entering the inside from the outside. "Waterproof" refers, for example, to IPX7 (no water can enter the inside when submerged in water 1 meter deep for 30 minutes) as specified in "Protection Ratings by Enclosures of Electrical Machinery and Equipment (IP Code)" in JIS C 0920. The inner cold-shrinkable tube 20 is made of, for example, EPDM (ethylene propylene diene rubber).

[0038] Fig. 3(a) is a schematic diagram of the outer cold-shrinkable tube 30. Fig. 3(b) is a cross-sectional view of the outer cold-shrinkable tube 30. As shown in Figs. 1, 3(a), and 3(b), the outer cold-shrinkable tube 30 covers the cable connection portion 10 and the inner cold-shrinkable tube 20. The diameter (outer diameter and inner diameter) of the outer cold-shrinkable tube 30 is larger than the diameter of the inner cold-shrinkable tube 20. For example, the axial (longitudinal) length of the outer cold-shrinkable tube 30 is longer than the axial length of the inner cold-shrinkable tube 20.

[0039] For example, the outer cold-shrinkable tube 30 covers at least a portion of the cable connection portion 10 and at least a portion of the inner cold-shrinkable tube 20. The outer cold-shrinkable tube 30 covers an area including a boundary portion B between the cable connection portion 10 and the inner cold-shrinkable tube 20. The outer cold-shrinkable tube 30 is made of, for example, a waterproof material, similar to the inner cold-shrinkable tube 20. The material of the outer cold-shrinkable tube 30 is, for example, EPDM.

[0040] For example, the outer cold-shrinkable tube 30 may be held in an expanded state around the diameter expansion holding member 33 before covering the cable connection portion 10 and the inner cold-shrinkable tube 20 (before attachment or use). Like the previously described diameter expansion holding member 23, the diameter expansion holding member 33 has a disassembly line 33b formed in the direction of the axis L2, allowing it to be pulled out along the disassembly line 33b as a string-like core ribbon 33c. Like the previously described diameter expansion holding member 23, the diameter expansion holding member 33 has a first end 33d, which is the starting end of the core ribbon 33c that is pulled out, and a second end 33f, which is the terminal end of the core ribbon 33c that is pulled out. Near the first end 33d, an exposed portion 33g is formed where the outer cold-shrinkable tube 30 is not attached and the outer surface of the diameter expansion holding member 33 is exposed, and another exposed portion 33g is formed near the second end 33f. In this manner, The shape and material of the diameter expansion holding member 33 can be the same as the shape and material of the diameter expansion holding member 23, for example.

[0041] The cable connection part 10 includes, for example, an insulating tube 11, a connector 12, and a semiconductive tape 13. The insulating tube 11 is configured as a cylindrical body having a hollow portion 11b that penetrates the cable 2 in the longitudinal direction D1. The insulating tube 11 includes, for example, an insulating tube main body 11c having the hollow portion 11b, a shielding mesh 11d, a water-shielding layer 11f, and a waterproof tube 11g. The insulating tube main body 11c is, for example, a one-piece molded rubber product. The exemplary insulating tube main body 11c may include insulating rubber, for example, ethylene propylene rubber or silicone rubber. For example, the insulating tube main body 11c includes insulating rubber 11c1 and conductive rubber 11c2. The conductive rubber 11c2 is provided, for example, at three locations: at each end of the insulating tube main body 11c in the longitudinal direction D1 and at the center of the insulating tube main body 11c in the longitudinal direction D1. The shielding mesh 11d covers at least a part of the insulating tube body 11c. The water-shielding layer 11f covers the shielding mesh 11d. For example, at least a part of the shielding mesh 11d is covered with an outer cold-shrinkable tube 30.

[0042] The insulating tube 11 covers, for example, the connector 12. FIG. 4 is a diagram schematically illustrating the insulating tube 11. As shown in FIG. 4, the insulating tube 11 may be held in an expanded state on the outer periphery of the diameter expansion holding member 11h before covering the connector 12 (before attachment or use). The diameter expansion holding member 11h has a disassembly line 11j, similar to the diameter expansion holding member 23 described above, and can be pulled out as a cord-like core ribbon along the disassembly line 11j. The material of the diameter expansion holding member 11h can be the same as the material of the diameter expansion holding member 23, for example.

[0043] The connector 12 connects, for example, conductors 2b extending from a pair of cables 2 facing each other along the longitudinal direction D1. FIG. 5 is a perspective view showing an exemplary connector 12. As shown in FIGS. 1 and 5, the connector 12 is, for example, a sleeve that connects multiple conductors 2b by crimping. The exemplary connector 12 has a cylindrical shape having an outer peripheral surface 12f with openings 12c formed at both ends. In this case, each of the pair of conductors 2b is inserted into each of the openings 12c of the connector 12, and crimping is performed with each of the pair of conductors 2b inserted, thereby electrically connecting the pair of conductors 2b to each other inside the connector 12.

[0044] Instead of the sleeve, a screw-type connector (also called a shear bolt connector) may be used as the connector 12. In this case, a plurality of threaded holes communicating with the internal space of the connector body are formed on the outer circumferential surface of the cylindrical connector body, and a bolt is screwed into each of the threaded holes to crimp the conductors inside the connector body. With a pair of conductors inserted into the connector body through each opening, each of the bolts is screwed into each of the threaded holes, electrically connecting the pair of conductors 2b to each other. When the cable connection unit 10 includes this connector 12, a crimping tool is not required, and the pair of conductors 2b can be easily connected. Although the types of connector 12 have been exemplified above, the type of connector is not particularly limited. Note that a semiconductive tape 13 is wrapped around the connector 12.

[0045] 6(a) and 6(b) are perspective views schematically showing the shielding treatment portion 16 of the cable connection structure 1. FIG. 7 is a cross-sectional view schematically showing the layer structure of the cable 2. As shown in FIGS. 6(a), 6(b), and 7, the cable 2 is stacked in this order from the inside in the radial direction of the cable 2: a conductor 2b, an insulating layer 2c, a semiconductive layer 2d, a shielding layer 2f, a semiconductive layer 2g, a water-shielding layer 2h, and a cable sheath 2j. The shielding treatment portion 16 indicates the portion of the shielding layer 2f, the semiconductive layer 2g, the water-shielding layer 2h, and the cable sheath 2j where the piercing terminal 40, the ground wire 50, and the grounding spring 60 are provided.

[0046] For example, the shielding treatment portion 16 has a portion 17 where the cable sheath 2j and the water-shielding layer 2h are separated from the shielding layer 2f, and an exposed portion 19 where the shielding layer 2f is exposed. The exposed portion 19 indicates a portion where the cable sheath 2j, the water-shielding layer 2h, and the semi-conductive layer 2g are stripped away to expose the shielding layer 2f. For example, the exposed portion 19 extends in the longitudinal direction D1 of the cable 2 and in the circumferential direction D2 of the cable 2. The portion 17 where the cable sheath 2j and the water-shielding layer 2h are separated from the shielding layer 2f is a portion between a pair of notches 18 aligned along the circumferential direction D2, and includes the cable sheath 2j and the water-shielding layer 2h rolled up from the shielding layer 2f. The portion 17 has, for example, a three-layer structure of the cable sheath 2j, the water-shielding layer 2h, and the semi-conductive layer 2g.

[0047] For example, the shielding treatment portion 16 has a plurality of (for example, two) portions 17 in which the cable sheath 2j and the water-shielding layer 2h are spaced from the shielding layer 2f, and the plurality of portions 17 are arranged along the circumferential direction D2. For example, a piercing terminal 40 and a grounding wire 50 are provided in each of the plurality of portions 17. The piercing terminal 40 and the grounding wire 50 are provided to electrically and mechanically connect the water-shielding layer 2h and the shielding layer 2f to each other and maintain the potential of the water-shielding layer 2h and the shielding layer 2f at the same potential. The piercing terminal 40 is fixed to the portion 17 by piercing the cable sheath 2j and the water-shielding layer 2h, and the grounding wire 50 extends from the piercing terminal 40.

[0048] For example, the ground wire 50 has a first bent portion 51 that extends from the piercing terminal 40 and bends along the inner side 17b of the spaced portion 17, a first extending portion 52 that extends along the inner side 17b, a second bent portion 53 that bends along the shielding layer 2f at the end of the first extending portion 52 opposite the first bent portion 51 (the inner end of the spaced portion 17), and a second extending portion 54 that extends from the second bent portion 53 to the exposed portion 19.

[0049] The second bent portion 53 is located, for example, at the root end of a portion 17 of the cable sheath 2j and the water-impermeable layer 2h that is spaced from the shielding layer 2f. However, the second bent portion 53 may be located at a portion other than the root end of the portion 17 (for example, an intermediate portion). The second extending portion 54 extends in the longitudinal direction D1 in the exposed portion 19, and the grounding spring 60 is wound around this extending portion. For example, the grounding spring 60 fastens the multiple ground wires 50 (second extending portion 54) to the shielding layer 2f.

[0050] As described above, the ground wire 50 is installed inside the cable sheath 2j with Z-shaped bent portions (e.g., the first bent portion 51 and the second bent portion 53) formed. The length of the bent portion of the ground wire 50 (e.g., the length from the first bent portion 51 to the second bent portion 53) is, for example, 20 mm or more. This allows the ground wire 50 to reliably maintain the connection between the water-shielding layer 2h and the shielding layer 2f even if the cable sheath 2j shrinks back by 20 mm or less. Furthermore, even if the relative positions of the cable sheath 2j and the shielding layer 2f shift due to thermal expansion or the like, the bent portion absorbs this shift, thereby reliably maintaining the electrical and mechanical connection between the water-shielding layer 2h and the shielding layer 2f. Furthermore, by tightening the ground wire 50 to the shielding layer 2f with the grounding spring 60, the connection between the shielding layer 2f and the water-shielding layer 2h can be further strengthened.

[0051] FIG. 8 is a perspective view showing a piercing terminal 40 to which an exemplary ground wire 50 is connected. FIG. 9(a) is a view showing an exemplary piercing terminal 40. FIG. 9(b) is a view showing an exemplary ground wire 50. FIG. 9(c) is a view showing an exemplary grounding spring 60. As shown in FIGS. 8, 9(a), and 9(b), the piercing terminal 40 may be a termifoil terminal attached to the end of the ground wire 50. The exemplary piercing terminal 40 includes a first portion 42 having a plurality of blade portions 41 that pierce the cable sheath 2j and the water-shielding layer 2h, a second portion 43 that is bent to approach the first portion 42, and a connecting portion 44 that is connected to the first portion 42.

[0052] The piercing terminal 40 is made of a conductive material (e.g., metal). For example, the piercing terminal 40 may include at least one of nickel plating and tin plating. The first portion 42 and the second portion 43 are, for example, plate-shaped. For example, the first portion 42 is continuous with the second portion 43 via a bent portion 45, and the second portion 43 is bent so as to approach the first portion 42 via the bent portion 45.

[0053] The connecting portion 44 has, for example, a tubular shape (a cylindrical shape, for example). The ground wire 50 is connected to the connecting portion 44 by, for example, crimping. Specifically, the ground wire 50 is connected to the connecting portion 44 by crimping the connecting portion 44 with the end of the ground wire 50 inserted into the connecting portion 44. The bent portion 45 extends, for example, along the direction D3 in which the ground wire 50 is inserted into the connecting portion 44.

[0054] The first portion 42 is located, for example, on an extension of the direction D3 of the connecting portion 44. As an example, the first portion 42 has a rectangular plate shape extending in the direction D3 and a direction D4 intersecting the direction D3. The first portion 42 has a blade portion 41 that pierces the cable sheath 2j and the water-shielding layer 2h. The first portion 42 has, for example, a plurality of through holes 42b penetrating the first portion 42 in the plate thickness direction, and the blade portions 41 protrude from the edges of the through holes 42b. For example, a plurality of (for example, four) blade portions 41 may protrude from the through holes 42b. As an example, the piercing terminal 40 has five blade portions 41. In this case, one of the five blade portions 41 may be disposed at the center of the first portion 42, and the remaining four may be disposed in a square shape. In this manner, one of the plurality of blade portions 41 may be disposed at the center of the first portion 42.

[0055] For example, the second portion 43 has a rectangular plate shape. Like the first portion 42, the second portion 43 may have a plurality of through holes 43b penetrating the second portion 43 in the plate thickness direction, and the blade portions 41 may protrude from the edges of the through holes 43b. The second portion 43 has an opposing surface that faces the first portion 42 when the second portion 43 is bent toward the first portion 42 via the bending portion 45, and the blade portions 41 protrude from the opposing surface, for example. The number of blade portions 41 included in the piercing terminal 40 is, for example, 2 or more and 10 or less. However, the number of blade portions 41 may be 1, 3 or more, 4 or more, 5 or more, or 10 or more, or may be 9 or less, 8 or less, 7 or less, or 6 or less.

[0056] The ground wire 50 has, for example, a flat shape. In this case, the ground wire 50 has a main surface 50b facing the portion 17 where the cable sheath 2j and the water-shielding layer 2h are spaced from the shielding layer 2f, as well as the shielding layer 2f, and an end surface 50c facing in a direction intersecting the main surface 50b. As an example, the ground wire 50 extends in a tape-like shape along its longitudinal direction, and the main surface 50b has a rectangular shape with long sides extending in the longitudinal direction. The ground wire 50 has, for example, a mesh shape. In this case, the ground wire 50 may be a braided wire.

[0057] For example, the ground wire 50 may be a flat braided wire (for example, a flat braided copper wire). The length of the ground wire 50 may be 100 mm or more and 200 mm or less (for example, 150 mm). The cross-sectional area of ​​the ground wire 50 may be 1.25 mm. 2 Above 14mm 2 For example, the ground wire 50 is formed by braiding a plurality of wires containing a conductive material. For example, the diameter of the wires is 0.12 mm, and the number of wires constituting the ground wire 50 is 490, so the cross-sectional area of ​​the ground wire 50 is 5.54 mm. 2 (=0.0012mm 2 However, the diameter and number of the wires, as well as the length and cross-sectional area of ​​the ground wire 50 are not limited to the above values.

[0058] The grounding spring 60 is, for example, a constant force spring. For example, the grounding spring 60 is tape-shaped. The grounding spring 60 exerts elastic force in the radial direction of the cable 2 when wrapped around the shielding layer 2f and the grounding wire 50. In the example described above, the cable connecting member 100 includes the inner cold-shrinkable tube 20, the outer cold-shrinkable tube 30, the piercing terminal 40, the grounding wire 50, and the grounding spring 60. However, the cable connecting member may also include the piercing terminal 40, the grounding wire 50, and the grounding spring 60, and the components that make up the cable connecting member can be changed as appropriate.

[0059] Next, an example of a method for connecting cables 2 according to this embodiment will be described. An example of connecting two cables 2 to each other will be described below. First, as shown in FIG. 10(a), a step of processing the cables is performed. At this time, terminal processing is performed on each of the pair of cables 2, in which the cable sheath 2j is stripped so that the conductor 2b and the insulating layer 2c are exposed in this order, and then the conductors 2b of the pair of cables 2 are made to face each other.

[0060] 10(b) and 10(c), a step of inserting members into the cable 2 is performed. At this time, the outer cold-shrinkable tube 30 expanded in diameter by the diameter expansion holding member 33 and the inner cold-shrinkable tube 20 expanded in diameter by the diameter expansion holding member 23 are inserted into the pair of cables 2, respectively. Then, the insulating tube 11 expanded in diameter by the diameter expansion holding member 11h is inserted into one of the pair of cables 2.

[0061] 11(a), a step of attaching the connector 12 is carried out. Specifically, each of the pair of conductors 2b is inserted into each of the openings 12c of the connector 12, and the connector 12 is crimped. As a result, the connector 12 fastens the pair of conductors 2b and electrically connects the pair of cables 2 to each other.

[0062] After connecting the pair of cables 2 with the connector 12, a step of winding the semiconductive tape 13 is carried out as shown in Fig. 11(b). At this time, the semiconductive tape 13 is wound around the connector 12. For example, the entire connector 12 is covered with the semiconductive tape 13.

[0063] 12(a) and 12(b), a step of attaching the insulating tube 11 is carried out. Specifically, the insulating tube 11 inserted into the cable 2 is moved, and for example, the core ribbon of the diameter expansion holding member 11h is pulled out, and the semiconductive tape 13 and the pair of cables 2 are fastened by the insulating tube 11. Thereafter, a shielding treatment is performed on both ends of the insulating tube 11 in the longitudinal direction D1, to form the shielding treatment portion 16.

[0064] 6(a), 6(b), 13, and 14 described above show specific procedures for forming the shielding processing portion 16. First, as shown in Fig. 13, the cable sheath 2j, the water-shielding layer 2h, and the semiconductive layer 2g of the cable 2 are stripped off at each end of the insulating tube 11 in the longitudinal direction D1 to form exposed portions 19 in which the shielding layer 2f is exposed.

[0065] Next, incisions 18 are made in the cable sheath 2j and the water-shielding layer 2h (the water-shielding layer 2h laminated with the semi-conductive layer 2g) of the cable 2 located on the opposite side of the exposed portion 19 from the insulating tube 11, and the cable sheath 2j and the water-shielding layer 2h are rolled up to form a portion 17 where the cable sheath 2j and the water-shielding layer 2h are spaced from the shielding layer 2f, thereby exposing the shielding layer 2f (a step of exposing the shielding layer). At this time, a pair of incisions 18 are made aligned along the circumferential direction D2 of the cable 2, and the portion between the pair of incisions 18 is rolled up to form the portion 17 spaced from the shielding layer 2f. For example, a plurality of (for example, two) spaced portions 17 are formed.

[0066] Meanwhile, the ground wire 50 is connected to the piercing terminal 40 (the step of connecting the ground wire to the piercing terminal). Specifically, one end of the ground wire 50 is inserted into the connecting portion 44 of the piercing terminal 40, and the connecting portion 44 with the ground wire 50 inserted therein is crimped to connect the ground wire 50 to the piercing terminal 40. The piercing terminal 40 is then pierced into the separated portion 17. At this time, for example, the separated portion 17 is sandwiched between the first portion 42 and the second portion 43, and the blade portion 41 is pierced into the cable sheath 2j and the water-shielding layer 2h of the separated portion 17. Specifically, with the connecting portion 44 of the piercing terminal 40 positioned at the end of the separated portion 17 in the longitudinal direction D1, the separated portion 17 is sandwiched between the first portion 42 and the second portion 43, and the blade portion 41 is pierced into the separated portion 17 to fix the piercing terminal 40 to the separated portion 17.

[0067] After the piercing terminal 40 is pierced into the portion 17 and fixed, as shown in Fig. 6(a), the ground wire 50 extending from the piercing terminal 40 is bent so as to follow the inner side 17b of the separated portion 17 and the shielding layer 2f (ground wire bending step). At this time, a Z-shaped bent portion is formed. As a specific example, the ground wire 50 extending from the connecting portion 44 is folded back so as to follow the inner side 17b of the portion 17 to form a first bent portion 51 (first bent portion forming step), and the ground wire 50 is then guided along the inner side 17b of the portion 17 to form a first extended portion 52 (first extended portion forming step). Then, a second bent portion 53 is formed by bending the first extension portion 52 from the end opposite the first bent portion 51 along the shielding layer 2f (step of forming the second bent portion), and the ground wire 50 is extended from the second bent portion 53 along the shielding layer 2f to form a second extension portion 54 (step of forming the second extension portion).

[0068] The step of bending the ground wire 50 as described above is performed, for example, on each of the plurality of spaced apart portions 17. Then, as shown in FIGS. 6(a) and 6(b), a grounding spring 60 is wound around the ground wire 50 extending along the shielding layer 2f (step of winding the grounding spring). At this time, the grounding spring 60 is wound around the ground wire 50 extending from the bent portion. As a specific example, the grounding spring 60 is installed by winding and fixing a tape-shaped grounding spring 60 around the ground wire 50. For example, the grounding spring 60 is wound around a plurality of ground wires 50.

[0069] After winding the grounding spring 60, the electrical continuity between the water-impermeable layer 2h and the shielding layer 2f is confirmed, and then the tape T is wound, as shown in Fig. 14. Then, as shown in Fig. 15(a), the step of attaching the inner cold-shrinkable tube 20 is carried out. Specifically, the inner cold-shrinkable tubes 20 inserted into the pair of cables 2 are moved to one side and the other side of the cable connection part 10 (positions adjacent to the cable connection part 10). Then, the core ribbon 23c of the diameter expansion retaining member 23 of each inner cold-shrinkable tube 20 is pulled out to shrink each inner cold-shrinkable tube 20, thereby clamping each one side and the other side of the cable connection part 10 by each inner cold-shrinkable tube 20.

[0070] 15(b), a step of attaching the outer cold-shrinkable tube 30 is performed. At this time, the outer cold-shrinkable tubes 30 inserted into the pair of cables 2 are moved to positions where they cover the cable connection portion 10 and the inner cold-shrinkable tube 20. Specifically, each outer cold-shrinkable tube 30 is moved to a position where it covers at least a portion of the cable connection portion 10 and at least a portion of the inner cold-shrinkable tube 20. Then, the core ribbon 33c of the diameter expansion retaining member 33 of each outer cold-shrinkable tube 30 is pulled out to shrink each outer cold-shrinkable tube 30. As a result, each outer cold-shrinkable tube 30 covers one side of the cable connection portion 10 in the longitudinal direction D1 and the inner cold-shrinkable tube 20, and the other side of the cable connection portion 10 in the longitudinal direction D1 and the inner cold-shrinkable tube 20. After this, a series of steps for connecting the pair of cables 2 to each other is completed.

[0071] Next, the effects obtained from the cable connecting method, cable connection structure 1, and cable connecting member 100 according to this embodiment will be described in detail. As illustrated in Figures 6(a) and 6(b), in the cable connecting method, cable connection structure 1, and cable connecting member 100 according to this embodiment, the cable sheath 2j and the water-proof layer 2h are stripped to expose the shielding layer 2f located inside the cable sheath 2j and the water-proof layer 2h, and a piercing terminal 40 with a ground wire 50 is pierced into a portion 17 of the cable sheath 2j and the water-proof layer 2h that is spaced apart from the shielding layer 2f. Therefore, by bringing the ground wire 50 extending from the piercing terminal 40 into contact with and fixing the shielding layer 2f, the water-proof layer 2h can be electrically and mechanically connected to the shielding layer 2f.

[0072] By electrically connecting the shielding layer 2f to the water-shielding layer 2h, the potential of the water-shielding layer 2h and the potential of the shielding layer 2f are made equal, thereby suppressing voltage induction. Therefore, discharge due to voltage induction can be suppressed. Furthermore, connecting the water-shielding layer 2h and the shielding layer 2f using the piercing terminal 40 and the grounding wire 50 eliminates the need for soldering, thereby improving connection reliability. The grounding wire 50 with the piercing terminal 40 can be connected to the shielding layer 2f by piercing it, reducing the number of components and facilitating installation of the cable connection structure 1. Furthermore, since the grounding wire 50 is bent along the cable sheath 2j, the inner side 17b of the water-shielding layer 2h, and the shielding layer 2f, even if thermal expansion or the like occurs, the bent portion can follow the thermal expansion or the like. Therefore, the connection between the water-shielding layer 2h and the shielding layer 2f can be more reliably maintained even when thermal expansion or the like occurs, thereby improving connection reliability.

[0073] The ground wire 50 may be flattened. In this case, the flattened portion of the ground wire 50 can be arranged along the outer peripheral surface of the shielding layer 2f, thereby improving the workability of installing the connection structure.

[0074] The ground wire 50 may have a mesh-like structure. In this case, the flexibility of the ground wire 50 can be increased, making it easier for the ground wire 50 to follow thermal expansion and the like. This further improves the reliability of the connection.

[0075] The cable connection method according to this embodiment may include a step of winding a grounding spring 60 around the ground wire 50 that extends from the bent portion along the shielding layer 2f. In this case, the ground wire 50 that contacts the shielding layer 2f can be fixed by winding the grounding spring 60 around it. This makes it possible to further improve the reliability of the connection without using solder. Furthermore, since dedicated tools such as a soldering iron are not required, high-quality connection reliability can be ensured even by non-experts.

[0076] The length of the ground wire 50 may be 100 mm or more and 200 mm or less. When the length of the ground wire 50 is 100 mm or more, the electrical and mechanical connection between the water-shielding layer 2h and the shielding layer 2f can be more reliably maintained. When the length of the ground wire 50 is 200 mm or less, the ground wire 50 can be easily fixed to the shielding layer 2f.

[0077] The cross-sectional area of ​​the ground wire 50 is 1.25 mm 2 Above 14mm 2 The cross-sectional area of ​​the ground wire 50 may be 1.25 mm or less. 2 This increases the strength of the ground wire 50. 2 By satisfying the following, the handling of the ground wire 50 can be made even easier.

[0078] In the step of fixing the piercing terminal 40, multiple (for example, two) piercing terminals 40 may be fixed. In this case, since multiple piercing terminals 40 are fixed, even if a connection failure occurs in one piercing terminal 40, the connections in the other piercing terminals 40 are maintained. This makes it possible to further increase the reliability of the connection and improve safety.

[0079] The piercing terminal 40 may have blade portions 41 that pierce the cable sheath 2j and the portion 17 of the water-shielding layer 2h that is spaced from the shielding layer 2f, and the number of blade portions 41 may be two or more and ten or less. Having two or more blade portions 41 enables the piercing terminal 40 to firmly connect to the cable sheath 2j and the water-shielding layer 2h. Having ten or less blade portions 41 simplifies the configuration of the piercing terminal 40, making it easier to make connections using the piercing terminal 40.

[0080] The above describes embodiments of the cable connection method, cable connection structure, and cable connection member according to the present disclosure. However, various modifications are possible within the scope of the claims. That is, the shape, size, number, and arrangement of the components of the cable connection structure and cable connection member, as well as the content and order of the steps of the cable connection method, may be modified as needed within the scope of the claims.

[0081] For example, in the above-described embodiment, an example was described in which the cable connecting member included the piercing terminal 40, the ground wire 50, and the grounding spring 60. However, the cable connecting member may include only at least one of the piercing terminal 40, the ground wire 50, and the grounding spring 60, and the components that make up the cable connecting member can be changed as appropriate.

[0082] The piercing terminal according to the present disclosure may be a piercing terminal attached to a ground wire and configured to pierce a portion of the cable sheath and the water shielding layer of a cable spaced from the shielding layer. The ground wire according to the present disclosure may be flat and braided, attached to the piercing terminal configured to pierce a portion of the cable sheath and the water shielding layer spaced from the shielding layer, and bent to fit the inside of the spaced portion and along the shielding layer. The grounding spring according to the present disclosure may be bent to fit the inside of the portion of the cable sheath and the water shielding layer spaced from the shielding layer and be wound around the ground wire extending from the shielding layer.

[0083] In the above embodiment, an example has been described in which the ground wire 50 is fixed in contact with the shielding layer 2f by winding the ground spring 60 around the ground wire 50. However, the means for fixing the ground wire 50 in contact with the shielding layer 2f is not limited to the ground spring 60. For example, the ground wire 50 may be fixed in contact with the shielding layer 2f by winding a braided wire around the ground wire 50 extending to the shielding layer 2f and soldering the braided wire to the shielding layer 2f, which is a shielding copper tape.

[0084] In the above-described embodiment, an example was described in which the ground wire 50 extending from the piercing terminal 40 is bent so as to follow the inner surface 17b of the separated portion 17 and the shielding layer 2f. At this time, for example, if the ground wire 50 is made of an elastic material, the ground wire 50 may be bent in a contracted state. This can further improve the ability of the ground wire 50 to respond to thermal expansion, etc. As described above, in the above-described embodiment, an example was described in which the ground wire 50 is a flat braided wire. However, the ground wire may be something other than a flat braided wire, such as a braided wire, a flat metal foil, or a metal wire.

[0085] In the above-described embodiment, the cable 2 is a power cable rated at 66 kV or more. However, the cable connection method, cable connection structure, and cable connection member according to the present disclosure may be applied to power cables of less than 66 kV.

[0086] Next, a cable connection method and a cable connection structure according to a modified example will be described with reference to Figures 16(a) and 16(b). Figures 16(a) and 16(b) show a shielding treatment section 76 of a cable connection structure according to a modified example. In the shielding treatment section 76, the piercing terminal 40 is fixed in a state where it is pierced into the cable sheath 2j and the water-shielding layer 2h, and the ground wire 50 extends from the piercing terminal 40.

[0087] The shielding treatment section 76 differs from the previously described shielding treatment section 16 in that the ground wire 50 extending from the piercing terminal 40 does not extend along the inner side 17b of the separated portion 17. In the shielding treatment section 76, the ground wire 50 has a first bent portion 51 extending from the piercing terminal 40 and bent toward the inside of the piercing terminal 40 (toward the radially inner side of the cable 2), a second bent portion 53 extending from the first bent portion 51 in the longitudinal direction D1 and bent inside the piercing terminal 40, and a second extending portion 54 extending from the second bent portion 53 to the exposed portion 19. The second bent portion 53 is located, for example, at the bottom of the piercing terminal 40. The second extending portion 54 extends in the longitudinal direction D1 in the exposed portion 19, and a grounding spring 60 is wound around this extending portion. In the ground wire 50 according to the modified example, the Z-shaped bent portions (first bent portion 51 and second bent portion 53) are exposed on the shielding layer 2f.

[0088] In the cable connection method according to the modified example, after a piercing terminal 40 is fixed to an end of a portion 17 where the cable sheath 2j and the water-shielding layer 2h are spaced from the shielding layer 2f, the ground wire 50 extending from the piercing terminal 40 is folded back to form a first bent portion 51 (a step of forming a first bent portion). Then, a second bent portion 53 is formed below the piercing terminal 40, bending the wire 50 along the shielding layer 2f (a step of forming a second bent portion). Then, the ground wire 50 is extended from the second bent portion 53 along the shielding layer 2f to form a second extending portion 54 (a step of forming a second extending portion). Then, a grounding spring 60 is wound around the second extending portion 54 extending along the shielding layer 2f (a step of winding the grounding spring). After winding the grounding spring 60, electrical continuity between the water-shielding layer 2h and the shielding layer 2f is confirmed, and then a tape T is wound around the wire 50.

[0089] The cable connection structures and cable connection methods according to the above-described variations also provide the same effects as the above-described shielding treatment portion 16. In the above-described variations, the Z-shaped bent portion (second bent portion 53) of the ground wire 50 is located inside the piercing terminal 40 (inside the radial direction of the cable 2). However, as shown in FIG. 17 , a shielding treatment portion 86 may be used in which the Z-shaped bent portion of the ground wire 50 is not located inside the piercing terminal 40 (is exposed at the shielding layer 2f). In the shielding treatment portion 86, the ground wire 50 has a first bent portion 51 that extends from the piercing terminal 40 and bends inward (toward the shielding layer 2f) at a position spaced apart from the piercing terminal 40, a second bent portion 53 that extends from the first bent portion 51 toward the piercing terminal 40 and bends inward at a position spaced apart from the piercing terminal 40, and a second extending portion 54 that extends from the second bent portion 53 to the exposed portion 19. Even in the case of this shielding processing part 86, the same effects as those of the above-described shielding processing parts 16 and 76 can be obtained.

[0090] (Example) Next, examples of the cable connection method, cable connection structure, and cable connection member according to the present disclosure will be described. Note that the present disclosure is not limited to the following examples. First, in the examples, a piercing terminal 40, a ground wire 50, and a ground spring 60 were prepared as shown in Figures 9(a), 9(b), and 9(c). In this example, the piercing terminal 40 was a piercing connector (Termifoil manufactured by Tyco), and the cross-sectional area of ​​the ground wire 50 was 5.5 mm 2 The length of the ground wire 50 was 150 mm. A constant force spring manufactured by 3M was used as the ground spring 60.

[0091] As shown in Figures 6(a) and 6(b), the above-described piercing terminal 40, ground wire 50, and grounding spring 60 were installed in a 66 kV cable 2. Specifically, two portions 17 spaced from the shielding layer 2f of the cable sheath 2j and the water-shielding layer 2h of the cable 2 were formed, and the piercing terminal 40 was pierced into each of the portions 17. The ground wire 50 was bent so as to follow the inner surface 17b of the portion 17 and the shielding layer 2f. Then, the grounding spring 60 was wound around the two ground wires 50 extending in the shielding layer 2f. Furthermore, tape T was wound around the wires as shown in Figure 14 to confirm electrical continuity between the water-shielding layer 2h and the shielding layer 2f. The cable connection structure according to the example was formed through the above steps. In contrast, the cable connection structure of the comparative example was formed as follows.

[0092] (Comparative Example) The same cable 2 as in the example was used. In the comparative example, the semiconductive layer 2g was peeled off from the shielding layer 2f and rolled up, and then the flat braided wire was soldered to the semiconductive layer 2g. After that, the flat braided wire extending above the shielding layer 2f was loosened and then fixed with a grounding spring.

[0093] Three samples of each of the cable connection structures of the above-described Examples and Comparative Examples were prepared, and a load was applied to each sample so that the cable sheath 2j moved back and forth approximately 10 mm along the longitudinal direction D1. The number of reciprocating movements was set to five.

[0094] As a result of the above experiment, in the cable connection structure of the comparative example in which soldering was performed on a flat braided wire, the solder connection came off in all three samples after five reciprocating movements. In contrast, in the cable connection structure of the example using the piercing terminal 40 and the ground wire 50, none of the three samples came off even after five reciprocating movements. Therefore, it was found that the example using the piercing terminal 40 and the ground wire 50 can obtain high conformability and improve connection reliability even when reciprocating movements such as thermal contraction occur in the cable 2. That is, in the example, because the excess length of the ground wire 50 connecting the water-shielding layer 2h and the shielding layer 2f is stored in a bent state inside the cable sheath 2j, it was found that the high conformability ensures reliable connection even when shrinkage of the cable sheath 2j or movement of the core of the cable 2 (movement of the portion inside the shielding layer 2f) occurs.

[0095] Next, another example of the structure of the ground wire in the cable connection structure 1 according to the embodiment will be described with reference to FIG. 18 . In addition to the ground wire 50 (which may be referred to as the water-shielding layer ground wire 50 for distinction) also shown in FIG. 14 , the cable connection structure 1 also includes a shielding layer ground wire 90 in FIG. 18 . The water-shielding layer ground wire 50 is a ground wire for grounding the water-shielding layer 2h, while the shielding layer ground wire 90 is a ground wire for grounding the shielding layer 2f. The shielding layer ground wire 90 is used when it is necessary to lower the potential of the shielding layer 2f. For example, in a long line, the potential of the shielding layer 2f of the cable 2 increases, so the shielding layer ground wire 90 is used when a ground wire is drawn out at an intermediate connection and connected to a ground electrode. While FIG. 18 shows both the water-shielding layer ground wire 50 and the shielding layer ground wire 90, an embodiment in which only one of them is provided is also possible. That is, (1) when a cable with a water-shielding layer is used and there is no need to lower the potential of the cable shielding layer, the water-shielding layer ground wire 50 alone is sufficient. (2) When a cable with a water-shielding layer is used and it is desired to lower the potential of the cable shielding layer, both the water-shielding layer ground wire 50 and the shielding layer ground wire 90 are used. (3) When a cable without a water-shielding layer is used and it is desired to lower the potential of the cable shielding layer, it is sufficient to use only the shielding layer ground wire 90. From Figure 19 onwards, the water-shielding layer ground wire 50 is omitted, but cases (2) and (3) will be explained together.

[0096] 19 shows a cross section. The shielding layer ground wire 90 extends from the bent portion P on the side opposite the grounding spring 60. The configuration of the shielding layer ground wire 90 is similar to that of the ground wire 50, for example. As an example, the shielding layer ground wire 90 is a flat braided wire. The cable connection structure 1 includes a first grounding lead portion 70 that connects the shielding layer 2f and the shielding layer ground wire 90, and a second grounding lead portion 80 that extends from the first grounding lead portion 70 on the side opposite the bent portion P and connects to a terminal 82.

[0097] The first grounding lead 70 is the portion where the shielding layer ground wire 90 is connected to the shielding layer 2f of the cable 2, and the shielding layer ground wire 90 is held down by a grounding spring 60. The inner cold-shrinkable tube 20 is a tube with a built-in water-shielding layer, and the first grounding lead 70 is provided inside the water-shielding layer of the inner cold-shrinkable tube 20. For example, the water-shielding layer of the inner cold-shrinkable tube 20 is a metal foil made of a metal material such as aluminum. In this case, if stress concentrates on the water-shielding layer of the inner cold-shrinkable tube 20, there is a possibility that a hole will be formed in the water-shielding layer. Therefore, to prevent stress from concentrating on the water-shielding layer of the inner cold-shrinkable tube 20, the first grounding lead 70 is made flat and has no irregularities.

[0098] The second ground lead section 80 includes the shielding layer ground wire 90 protruding from the inner cold-shrinkable tube 20 and is where the shielding layer ground wire 90 connects to a terminal 82 at a position extending from the first ground lead section 70 in the longitudinal direction of the cable 2. The second ground lead section 80 includes a grounding wire lead protector 81 that protects the drawn-out shielding layer ground wire 90, a terminal 82 that connects to the shielding layer ground wire 90, and a metal member 83 that extends from the terminal 82 on the side opposite the shielding layer ground wire 90. For example, the grounding wire lead protector 81 includes a tape 81b that covers the exposed shielding layer ground wire 90 and is attached to the terminal 82, and a waterproof tube 81c that encases the cable 2 and the tape 81b. For example, the tape 81b is an adhesive polyethylene tape, and the waterproof tube 81c is made of EPDM. The waterproof tube 81c is a tube without a water-impermeable layer. For example, the waterproof tube 81c is a cold-shrinkable tube.

[0099] A portion of the second grounding lead portion 80 that does not have the inner cold-shrinkable tube 20 may have irregularities, as this corresponds to a portion where stress on the water-shielding layer of the inner cold-shrinkable tube 20 does not need to be considered. The terminal 82 and the metal member 83 are arranged at a position away from the inner cold-shrinkable tube 20. For example, the terminal 82 is joined to the metal member 83 by a bolt nut 84. As an example, the portion where the terminal 82 and the bolt nut 84 are provided protrudes from the cable 2.

[0100] Metal member 83 is made of, for example, copper. As an example, metal member 83 has a plate shape. For example, metal member 83 has a connection portion 83b that is connected to terminal 82 and covered by ground wire lead protector 81, and an extension portion 83c that is not covered by ground wire lead protector 81 and extends from connection portion 83b outward from ground wire lead protector 81. Connection portion 83b is the portion of metal member 83 on the terminal 82 side and corresponds to the portion that is connected to terminal 82 via bolt and nut 84.

[0101] For example, the connection portion 83b extends substantially parallel to the cable 2. Putty material 85 (butyl putty, for example) may be interposed between the connection portion 83b and the ground wire lead protector 81 (tape 81b) and between the connection portion 83b and the cable 2. Furthermore, the connection portion 83b may be spaced apart from the cable 2. For example, the extending portion 83c extends obliquely radially outward of the cable 2 as it moves away from the connection portion 83b.

[0102] Next, a method for assembling the cable connection structure 1 including the first grounding lead portion 70 and the second grounding lead portion 80 will be described. First, as shown in Fig. 20, with the insulating tube 11 of the cable connection portion 10 attached to the cable 2, the shielding layer ground wire 90 is fixed to the shielding layer 2f of the cable 2 by the grounding spring 60, and the shielding layer ground wire 90 is drawn out (step of forming the first grounding lead portion). Then, a bent portion P is formed. Note that portion P is an excess length that allows the shielding layer ground wire 90 to follow when the cable 2 expands and contracts in the longitudinal direction due to thermal expansion and contraction.

[0103] 21, an inner cold-shrinkable tube 20 is placed so as to cover the bent portion P of the shielding layer ground wire 90. Then, a terminal 82 is connected to the portion of the shielding layer ground wire 90 extending from the inner cold-shrinkable tube 20, and the terminal 82 is connected to a metal member 83 with a bolt and nut 84 (a step of forming a second grounding lead portion). At this time, putty material 85 may be placed between the metal member 83 and the cable 2.

[0104] Next, for example, putty material 85 is attached onto metal member 83, and tape 81b is wrapped around connection portion 83b of metal member 83, terminal 82, and the exposed portion of shielding layer ground wire 90 (a process of wrapping tape around the exposed portion of the shielding layer ground wire). Then, as shown in Figures 19 and 22, tape 81b is covered with waterproof tube 81c (a process of covering with waterproof tube). After attaching grounding wire lead protector 81 in this manner, the cable connection structure 1 shown in Figure 19 is completed, and the series of processes for assembling the cable connection structure 1 is also completed.

[0105] Next, a modified example of a cable connection structure including a first ground lead portion 70 and a second ground lead portion 80 will be described. Below, explanations that overlap with those previously described will be omitted where appropriate. As shown in FIG. 23, a cable connection structure 1A according to the modified example includes a ground lead protector 81A that is different from the ground lead protector 81. The ground lead protector 81A differs from the ground lead protector 81 in that it does not include a waterproof tube. For example, the ground lead protector 81A includes a self-fusing tape 81d that is attached to the terminal 82 and a tape 81f that covers the self-fusing tape 81d. As an example, the tape 81f is an adhesive polyethylene tape.

[0106] Next, a further modified example of a cable connection structure including a first grounding lead portion 70 and a second grounding lead portion 80 will be described. As shown in Fig. 24, a cable connection structure 1B according to this modified example does not have a terminal 82, and includes a metal member 83B that is different from the metal member 83. The metal member 83B has a terminal portion 83d in addition to the connection portion 83b and extension portion 83c described above. The terminal portion 83d is located at the end of the connection portion 83b on the side of the shielding layer ground wire 90, and functions as a terminal to which the shielding layer ground wire 90 is connected.

[0107] 24 and 25 , for example, terminal portion 83d of metal member 83B has a cylindrical shape that protrudes from plate-like connection portion 83b. In this case, shielding layer grounding wire 90 is inserted into the inside of cylindrical terminal portion 83d and crimped inside terminal portion 83d, thereby connecting shielding layer grounding wire 90 to metal member 83B. In this way, in cable connection structure 1B according to the modified example, terminal portion 83d integrated with metal member 83 is connected to shielding layer grounding wire 90 instead of terminal 82, which eliminates the need for bolts and nuts 84 and reduces the number of parts.

[0108] As described above, in the cable connection structures 1, 1A, and 1B including the first ground lead portion 70 and the second ground lead portion 80, the shielding layer ground wire 90 includes the first ground lead portion 70 connected to the shielding layer 2f and the second ground lead portion 80 connected to a terminal at a position extending from the first ground lead portion 70 in the longitudinal direction of the cable 2. The first ground lead portion 70 is provided inside the water-shielding layer of the inner cold-shrinkable tube 20, which is a tube with a built-in water-shielding layer. Therefore, the occurrence of irregularities in the first ground lead portion 70 can be suppressed, thereby suppressing wrinkles in the water-shielding layer of the inner cold-shrinkable tube 20. As a result, the formation of holes in the water-shielding layer can be more reliably suppressed. Furthermore, the second ground lead portion 80 located outside the inner cold-shrinkable tube 20 is covered with the ground wire lead protector 81, 81A, thereby protecting the second ground lead portion 80 located outside the inner cold-shrinkable tube 20.

[0109] Various examples of cable connection structures including a first ground lead portion and a second ground lead portion have been described above. However, the structures of the first ground lead portion and the second ground lead portion are not limited to the above examples and can be modified in various ways. For example, in the above example, the second ground lead portion 80 was described, which includes a ground wire lead protector 81, a terminal 82, a metal member 83, bolts and nuts 84, and a putty material 85. However, the components that make up the second ground lead portion are not limited to the above examples and can be modified as appropriate. The same applies to the first ground lead portion. [Explanation of symbols]

[0110] 1...cable connection structure, 2...cable, 2b...conductor, 2c...insulating layer, 2d...semiconductive layer, 2f...shielding layer, 2g...semiconductive layer, 2h...waterproof layer, 2j...cable sheath, 10...cable connection portion, 11...insulating tube, 11b...hollow portion, 11c1...insulating rubber, 11c2...conductive rubber, 11d...shielding mesh, 11f...waterproof layer, 11g...waterproof tube, 11h...expansion holding member, 11j...disassembly line, 12...connector, 12c...opening , 12f...outer surface, 13...semiconductive tape, 16, 76, 86...shielding processing portion, 17...separated portion, 17b...inside, 18...notch, 19...exposed portion, 20...inner cold-shrinkable tube, 23...diameter expansion holding member, 23b...disassembly line, 23c...core ribbon, 23d...first end, 23f...second end, 23g...exposed portion, 30...outer cold-shrinkable tube, 33...diameter expansion holding member, 33b...disassembly line, 33c...core ribbon, 33d...first end End, 33f...Second end, 33g...Exposed part, 40...Piercing terminal, 41...Blade part, 42...First part, 42b...Through hole, 43...Second part, 43b...Through hole, 44...Connecting part, 45...Bending part, 50...Grounding Line, 50b...main surface, 50c...end surface, 51...first bent part, 52...first extension part, 53...second bending part, 54...second extension part, 60...grounding spring, 70...first grounding drawer part, 80...second grounding drawer part, 81 ,81A...grounding wire pull-out protection part, 81b...tape, 81c...waterproof tube, 81d...self-fusing tape, 81f...tape, 82...terminal, 83, 83B...metal part, 83b...connection part, 83c...extension part, 83d...terminal part, 84...bolt nut, 85...putty material, 90...shielding layer grounding wire, 100...cable connection part, B...boundary part, D1...longitudinal direction, D2...circumferential direction, D3, D4...direction, L1, L2...axial line, T...tape.

Claims

1. A cable connection method for a cable having a water impermeable layer located inside a cable sheath and a shielding layer located inside the water impermeable layer, comprising: stripping the cable sheath and the water impermeable layer to separate the cable sheath and the water impermeable layer from the shielding layer, thereby exposing the shielding layer; a step of fixing a piercing terminal attached to a ground wire to the cable sheath and the portion of the water-shielding layer spaced apart from the shielding layer by piercing the piercing terminal into the cable sheath and the portion of the water-shielding layer spaced apart from the shielding layer; connecting the ground wire extending from the piercing terminal to the shielding layer in a bent state; A cable connection method comprising:

2. The ground wire has a flat shape. The cable connection method according to claim 1 .

3. The ground wire has a mesh pattern.

3. The cable connection method according to claim 1 or 2.

4. and winding a grounding spring around the ground wire extending from the bent portion along the shielding layer. The cable connection method according to any one of claims 1 to 3.

5. The length of the ground wire is 100 mm or more and 200 mm or less. The cable connection method according to any one of claims 1 to 4.

6. The cross-sectional area of ​​the ground wire is 1.25 mm ２ More than 14mm ２ Below is the The cable connection method according to any one of claims 1 to 5.

7. 7. The cable connecting method according to claim 1, wherein in the step of fixing the piercing terminal, a plurality of the piercing terminals are fixed.

8. the piercing terminal has a blade portion configured to pierce the cable sheath and the water-proof layer at a portion spaced from the shielding layer, The number of the blade portions is 2 or more and 10 or less. The cable connection method according to any one of claims 1 to 7.

9. A cable connection structure provided to a cable having a water impermeable layer located inside a cable sheath and a shielding layer located inside the water impermeable layer, A ground wire and a piercing terminal attached to the ground wire and configured to pierce the cable sheath and a portion of the water-shielding layer spaced apart from the shielding layer; Equipped with the ground wire is connected to the shielding layer in a bent state. Cable connection structure.

10. The ground wire has a flat shape. The cable connection structure according to claim 9.

11. The ground wire has a mesh pattern. The cable connection structure according to claim 9 or 10.

12. a shielding layer ground line extending from the shielding layer; the shielding layer ground wire has a first ground lead portion connected to the shielding layer and a second ground lead portion connected to a terminal at a position extending from the first ground lead portion in the longitudinal direction of the cable, the first grounding lead-out portion is located inside a tube with a built-in water impermeable layer that covers the cable, and the second grounding lead-out portion is located outside the tube with a built-in water impermeable layer, a ground wire lead protection part covering the second ground lead part; The cable connection structure according to any one of claims 9 to 11.

13. A cable connection structure provided to a cable having a water impermeable layer located inside a cable sheath and a shielding layer located inside the water impermeable layer, a shielding layer ground wire and a ground wire lead-out protection section led out from the shielding layer; the shielding layer ground wire has a first ground lead portion connected to the shielding layer and a second ground lead portion connected to a terminal at a position extending from the first ground lead portion in the longitudinal direction of the cable, the first grounding lead-out portion is located inside a tube with a built-in water impermeable layer that covers the cable, and the second grounding lead-out portion is located outside the tube with a built-in water impermeable layer, the ground wire lead protection portion covers the second ground lead portion; Cable connection structure.

14. A cable connection member to be attached to a cable having a water impermeable layer located inside a cable sheath and a shielding layer located inside the water impermeable layer, a flat and mesh-like grounding wire; a piercing terminal attached to the ground wire and configured to pierce the cable sheath and the water impermeable layer at a portion thereof spaced apart from the shielding layer; a grounding spring wound around the grounding wire extending along the shielding layer; A cable connection member comprising:

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