Cable connection method, cable connection structure, and cable connection component

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] This disclosure relates to a cable connection method, a cable connection structure, and a cable connection component. [Background technology]

[0002] Patent Document 1 describes a method for forming a connection portion of a plastic-insulated power cable with a water-blocking layer. In this method, when forming a connection portion of a plastic-insulated power cable having a water-blocking layer made of metal laminate tape, which is a metal tape with a plastic layer laminated on top of it, the end of the plastic sheath to which the water-blocking layer is in close contact is cut into strips. A metal grounding wire is soldered to the exposed metal tape surface by folding back this cut portion, and the grounding wire is electrically connected to the metal shielding layer of the cable.

[0003] Patent Document 2 describes a grounding structure for a power cable with a watertight layer. This grounding structure is for a power cable with a watertight layer having a cable watertight layer made of metal laminate interposed between the cable sheath and the cable shielding layer. The grounding structure comprises a grounding terminal connected to a grounding wire and a fastener that electrically and mechanically connects the grounding terminal and the cable watertight layer. The fastener is composed of a single-threaded screw consisting of a first fastener and a second fastener. The grounding terminal is fixed to the cable watertight layer by screwing together the first fastener, which is inserted from the cable watertight layer side into a through-hole that penetrates the cable sheath and the cable watertight layer radially, and the second fastener, which is inserted from the cable sheath side into the through-hole and tightened to the first fastener. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 147905 / 1983 [Patent Document 2] Japanese Patent Publication No. 2019-122103 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] As mentioned above, when cutting a plastic sheath into strips and soldering a metal ground wire to the exposed metal tape surface by folding back the cut ends, there is a concern that high strength cannot be obtained at the soldered joint. In other words, there is a concern that the strength of the soldered joint will decrease due to thermal expansion and contraction. Furthermore, the reliability of the soldered joint depends on the skill level of the worker performing the soldering, so there is room for improvement in terms of connection reliability.

[0006] The aforementioned grounding structure comprises a grounding terminal connected to a grounding wire, a first fastener inserted into a through-hole from the cable waterproofing layer side, and a second fastener inserted into the through-hole from the cable sheath side and tightened onto the first fastener. In this grounding structure, through-holes are formed in the cable sheath and cable waterproofing layer, and the first and second fasteners are inserted into these through-holes, with the second fastener being tightened onto the first fastener. In this way, through-holes are formed in the cable sheath and cable waterproofing layer in advance, so there is room for improvement in the workability of installing the cable connection structure. [Means for solving the problem]

[0007] The cable connection method according to this disclosure is 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 the steps of: stripping the cable sheath and the water-impermeable layer to separate the cable sheath and the water-impermeable layer from the shielding layer to expose the shielding layer; piercing a piercing terminal attached to a grounding wire into the portion of the cable sheath and the water-impermeable layer separated from the shielding layer to fix the piercing terminal to the portion of the cable sheath and the water-impermeable layer separated from the shielding layer; and connecting the grounding wire extending from the piercing terminal to the shielding layer in a bent state.

[0008] In this cable connection method, the cable sheath and waterproofing layer are stripped to expose the shielding layer located inside the cable sheath and waterproofing layer, and a piercing terminal with a ground wire is inserted into the portion of the cable sheath and waterproofing layer spaced apart from the shielding layer. Therefore, by contacting and fixing the ground wire extending from the piercing terminal to the shielding layer, the waterproofing layer can be electrically and mechanically connected to the shielding layer. By electrically connecting the shielding layer to the waterproofing layer, the potential of the waterproofing layer and the potential of the shielding layer can be made the same, thereby suppressing the induction of voltage. Therefore, discharge associated with the induction of voltage can be suppressed. In addition, since the waterproofing layer and the shielding layer are connected by the piercing terminal and the ground wire, soldering can be eliminated, thereby increasing the reliability of the connection. Since the ground wire with the piercing terminal can be connected to the shielding layer by inserting the piercing terminal, the number of parts can be reduced, and the installation work of the cable connection structure can be made easier. Furthermore, since the ground wire is connected to the shielding layer in a bent state, even if thermal expansion occurs, the bent portion can follow this thermal expansion. Therefore, even if thermal expansion occurs, the connection between the waterproofing layer and the shielding layer can be maintained more reliably, thus increasing the reliability of the connection.

[0009] The grounding wire may be flattened.

[0010] The grounding wire may have a braided structure.

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

[0012] The length of the grounding wire may be 100 mm or more and 200 mm or less.

[0013] The cross-sectional area of ​​the grounding wire is 1.25 mm². 2 The above and 14mm 2 The following is also acceptable.

[0014] In the process of securing the piercing terminals, multiple piercing terminals may be secured.

[0015] The piercing terminal may have a blade that penetrates the portion of the cable sheath and waterproof layer that is separated from the shielding layer, and the number of blades may be 2 or more and 10 or less.

[0016] The cable connection structure according to this disclosure is provided for a cable having a watertight layer located inside a cable sheath and a shielding layer located inside the watertight layer, and comprises a grounding wire and a piercing terminal attached to the grounding wire that penetrates a portion of the cable sheath and the shielding layer spaced apart from the shielding layer, wherein the grounding 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 waterproof layer, and a shielding layer, and the cable sheath and waterproof layer have portions separated from the shielding layer. A piercing terminal with a grounding wire is inserted into the separated portion of the cable sheath and waterproof layer. The grounding wire extending from the piercing terminal is connected to the shielding layer in a bent state. Therefore, by contacting and fixing the grounding wire extending from the bent portion to the shielding layer, the waterproof layer can be electrically and mechanically connected to the shielding layer. Thus, the potential of the waterproof layer and the shielding layer can be made the same, suppressing the induction of voltage and suppressing discharge associated with voltage induction. Similar to the cable connection method described above, since the connection between the waterproof layer and the shielding layer is made by the piercing terminal and the grounding wire, soldering can be eliminated and the reliability of the connection can be increased. Since the grounding wire can be connected to the shielding layer by inserting the piercing terminal into the cable sheath and grounding wire, the number of parts can be reduced and the installation work of the cable connection structure can be made easier. Since the grounding wire is connected to the shielding layer in a bent state, even if thermal expansion occurs, the bent portion can follow the thermal expansion. Therefore, even if thermal expansion occurs, the connection between the waterproofing layer and the shielding layer can be maintained more reliably, thus increasing the reliability of the connection.

[0018] A cable connection structure according to another aspect of the present disclosure has a shielding layer ground wire drawn from a shielding layer. The shielding layer ground wire has a first ground lead-out portion connected to the shielding layer and a second ground lead-out portion connected to a terminal at a position extending in the longitudinal direction of the cable from the first ground lead-out portion. The first ground lead-out portion is located inside a water-blocking layer built-in tube covering the cable, the second ground lead-out portion is located outside the water-blocking layer built-in tube, and a ground wire lead-out protection portion covering the second ground lead-out portion is provided.

[0019] In this cable connection structure, the shielding layer ground wire has a first ground lead-out portion connected to the shielding layer and a second ground lead-out portion connected to a terminal at a position extending in the longitudinal direction of the cable from the first ground lead-out portion, and the first ground lead-out portion is provided inside the water-blocking layer built-in tube. Therefore, generation of unevenness in the first ground lead-out portion can be suppressed, and wrinkling of the water-blocking layer of the water-blocking layer built-in tube can be suppressed. Further, since the second ground lead-out portion located outside the water-blocking layer built-in tube is covered with the ground wire lead-out protection portion, the second ground lead-out portion located outside the water-blocking layer built-in tube can be protected.

[0020] A cable connection member according to the present disclosure is a cable connection member attached to a cable having a water-blocking layer located inside a cable sheath and a shielding layer located inside the water-blocking layer, and includes a flat and net-shaped ground wire, a piercing terminal attached to the ground wire and piercing into a portion spaced apart from the shielding layers of the cable sheath and the water-blocking 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 grounding wire pierces a portion separated from the shielding layers of the cable sheath and the water blocking layer. The grounding wire extending from the piercing terminal is arranged to extend along the shielding layer. Therefore, by bringing the grounding wire extending from the piercing terminal piercing the cable sheath and the water blocking layer into contact with and fixing it to the shielding layer, the water blocking layer can be electrically and mechanically connected to the shielding layer. Accordingly, the potential of the water blocking layer and the potential of the shielding layer can be made the same potential to suppress the induction and discharge of voltage. Also, since soldering is not required, the reliability of the connection can be enhanced, and since the piercing terminal can be pierced into the cable sheath and the grounding wire to connect the grounding wire to the shielding layer, the installation work of the cable connection structure can be easily performed. In this cable connection member, the grounding wire contacting the shielding layer can be fixed by winding it with a grounding spring. Therefore, the reliability of the connection can be further enhanced without using solder. Also, since the grounding wire extending from the piercing terminal can be arranged in a bent state along the inside of the cable sheath and the water blocking layer and along the shielding layer, even if thermal expansion or the like occurs, the bent portion can follow the thermal expansion or the like. Therefore, even if thermal expansion or the like occurs, the connection between the water blocking layer and the shielding layer can be more reliably maintained, and the reliability of the connection can be further enhanced.

Effect of the Invention

[0022] According to the present disclosure, the reliability of the connection can be enhanced, and the installation work of the cable connection structure can be easily performed.

Brief Description of the Drawings

[0023] [Figure 1] It is a cross-sectional view showing a cable connection structure according to an embodiment. [Figure 2] (a) is a diagram schematically showing an inner normal-temperature shrinkable tube according to an embodiment. (b) is a cross-sectional view showing an example of the inner normal-temperature shrinkable tube according to an embodiment. [Figure 3](a) is a schematic diagram showing an outer room temperature shrinkable tube according to the embodiment. (b) is a cross-sectional view showing an example of an outer room temperature shrinkable tube according to the embodiment. [Figure 4] This figure shows the insulating tube of the cable connection member according to the embodiment. [Figure 5] This diagram shows a connector for a cable connection member according to an embodiment. [Figure 6] (a) and (b) are diagrams showing the cable connection structure according to the embodiment. [Figure 7] This is a cross-sectional view of an exemplary cable. [Figure 8] This figure shows the piercing terminal and ground wire of the cable connection member according to the embodiment. [Figure 9] (a) is a diagram showing the piercing terminal of the cable connection member according to the embodiment. (b) is a diagram showing the grounding wire of the cable connection member according to the embodiment. (c) is a diagram showing the grounding spring of the cable connection member according to the embodiment. [Figure 10] (a), (b), and (c) are diagrams showing the procedure for connecting cables according to the embodiment. [Figure 11] (a) and (b) are diagrams showing the procedure for connecting cables according to the embodiment. [Figure 12] (a) and (b) are diagrams showing the procedure for connecting cables according to the embodiment. [Figure 13] This figure shows the procedure for connecting cables according to the embodiment. [Figure 14] This figure shows the procedure for connecting cables according to the embodiment. [Figure 15] (a) and (b) are diagrams showing the procedure for connecting cables according to the embodiment. [Figure 16] (a) and (b) are diagrams showing cable connection structures according to modified examples. [Figure 17] This diagram shows a modified cable connection structure. [Figure 18] This diagram schematically shows the shielding layer grounding wire in a cable connection structure. [Figure 19] This is a cross-sectional view showing examples of the first and second grounding lead-out portions of the shielding layer grounding wire in a cable connection structure. [Figure 20] This is a schematic side view showing the first grounding outlet. [Figure 21] This is a schematic side view showing the first grounding outlet and the second grounding outlet. [Figure 22] This is a schematic side view showing the grounding wire outlet protection section that covers the second grounding outlet section. [Figure 23] This is a cross-sectional view showing a modified example of a ground wire outlet protection section. [Figure 24] This is a cross-sectional view showing a modified example of a ground wire outlet protection section. [Figure 25] Figure 24 is a schematic perspective view showing the metal component of the second grounding lead-out section. [Modes for carrying out the invention]

[0024] The following describes in detail embodiments of the cable connection method, cable connection structure, and cable connection member according to this disclosure, with reference to the drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numeral, and redundant explanations are omitted as appropriate. In addition, for the sake of ease of understanding, some parts of the drawings may be simplified or exaggerated, and the dimensional ratios, etc., 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 encompasses a wide variety of cable types. "Cable connection" includes connection points and their surroundings that connect multiple cables to each other, connection points and their surroundings that connect a cable to a connector, and connection points and their surroundings that connect a cable to equipment other than a connector. In this disclosure, the term "inside" refers to the conductor side of the cable in the cable covering material, i.e., the radially inner side of the cable. "Outside" refers to the opposite side of the conductor (cable sheath side) in the cable covering material, i.e., the radially outer side of the cable.

[0026] In this embodiment, the cable comprises a cable sheath, a waterproofing layer, and a shielding layer. "Cable sheath" refers to the outer covering of the cable. "Waterproofing layer" refers to a layer that blocks moisture, including humidity. "Shielding layer" is a grounded metal layer, for example, made of copper. Piercing terminals attached to a grounding wire are inserted into the cable sheath and waterproofing layer. "Grounding wire" refers to 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 Figure 1, the exemplary cable connection structure 1 according to this embodiment comprises a pair of cables 2, a cable connection part 10 that connects the pair of cables 2 to each other, a pair of inner pre-stretched tubes (inner cold shrink PST tubes) 20 that cover the cables 2, and a pair of outer pre-stretched tubes (outer cold shrink PST tubes) 30 that cover the cable connection part 10 and the inner cold shrink tubing 20.

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

[0029] The cross-sectional area of ​​conductor 2b is, for example, 80 mm². 2 ) or more and 600 (mm 2 The outer diameter (diameter) of the cable connection part 10 is 90 mm or larger. 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 larger and 145 mm or smaller. 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 the end of the 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 to be aligned along the longitudinal direction D1 of the cable connection structure 1. An exemplary cable connection member 100 includes an inner room temperature shrink tube 20 that covers the portion adjacent to the cable connection part 10, an outer room temperature shrink tube 30 that covers the cable connection part 10 and the inner room temperature shrink tube 20, a piercing terminal 40 fixed to the coiled cable 2 (see Figures 6(a) and 6(b)), a grounding wire 50 extending from the piercing terminal 40, and a grounding spring 60 that is wrapped around the grounding wire 50 and the shielding layer 2f.

[0031] Figure 2(a) is a schematic perspective view showing an exemplary inner room-temperature shrinkable tube 20. Figure 2(b) is a schematic cross-sectional view of the inner room-temperature shrinkable tube 20. As shown in Figures 2(a) and 2(b), the inner room-temperature shrinkable tube 20 may be expanded by an expansion-retaining member 23. The expansion-retaining member 23 has a dismantling line 23b formed along the direction in which the axis L1 of the expansion-retaining member 23 extends (hereinafter sometimes referred to as the axial direction). The expansion-retaining member 23 is, for example, a cylindrical, tubular, hollow member. The dismantling line 23b is formed to circumferentially or gradually advance in the axial direction while circumferentially or by reversing direction around the axis L1 of the expansion-retaining member 23.

[0032] As an example, the material used for the diameter-expanding retaining member 23 is a resin material such as polyethylene or polypropylene. The diameter-expanding retaining member 23 can be pulled out as a string-like core ribbon 23c along the dismantling line 23b. The part where the dismantling line 23b is formed is thinner than the surrounding area and is prone to breaking.

[0033] For example, the dismantling line is not limited to being formed in a spiral shape like the dismantling line 23b, but may also be formed in an SZ shape, and can be any shape as long as it can be pulled out. When the core ribbon 23c is pulled, the diameter-expanding holding member 23 breaks sequentially along the dismantling line 23b and is continuously pulled out as a new core ribbon 23c. Since the dismantling line 23b is formed at a constant pitch, for example, the width of the core ribbon 23c that is pulled out is constant. However, the width of the core ribbon 23c does not have to be constant.

[0034] The dismantling line 23b may be formed only on the inner circumferential surface of the diameter-expanding retaining member 23, only on the outer circumferential surface of the diameter-expanding retaining member 23, or on both the inner and outer circumferential surfaces of the diameter-expanding retaining member 23. The diameter-expanding retaining member 23 having the dismantling line 23b may be manufactured, for example, by spiraling the dismantling line 23b and fixing adjacent dismantling lines 23b together by bonding, welding, engaging, or a combination thereof, or by directly forming the dismantling line 23b on a cylindrical member.

[0035] As a removable tubular hollow diameter-expanding retaining member, there are two embodiments: one in which the inner room-temperature shrink tube is sequentially shrunk by pulling the core ribbon, as in the diameter-expanding retaining member 23 described above; and another in which the diameter-expanding retaining member slides against the inner room-temperature shrink tube and is pulled out from the inner room-temperature shrink tube, thereby detaching. The diameter-expanding retaining member 23 has a first end 23d which is the starting end that is pulled out as the core ribbon 23c, and a second end 23f which is the ending end that is pulled out as the core ribbon 23c. Near the first end 23d, an exposed portion 23g is formed where the inner room-temperature shrink tube 20 is not attached and the outer circumferential surface of the diameter-expanding retaining member 23 is exposed, and an exposed portion 23g is also formed near the second end 23f.

[0036] The core ribbon 23c, disassembled from the first end 23d, is passed, for example, through the inside of the diameter-expanding retaining member 23 and pulled out from the second end 23f side. As the core ribbon 23c is pulled out at the second end 23f side, the diameter-expanding retaining member 23 is sequentially disassembled from the first end 23d toward the second end 23f. In this embodiment, since the core ribbon 23c is formed along the entire length in the axial direction, it is possible to completely disassemble the diameter-expanding retaining member 23 from the first end 23d toward the second end 23f. However, it is sufficient that a disassembly line 23b is formed in at least the portion of the diameter-expanding retaining member 23 that expands and holds the inner room-temperature shrinkable tube 20, and there may be portions in a predetermined area on the second end 23f side where a disassembly line 23b is not formed.

[0037] As an example, the inner room temperature shrink tube 20 is a member that is expanded in diameter and held on the outer circumference of the diameter expansion holding member 23. The inner room temperature shrink tube 20 covers the portion of the cable 2 adjacent to the cable connection portion 10. The inner room temperature shrink tube 20 is made of, for example, rubber that shrinks at room temperature and has excellent elasticity. The inner room temperature shrink tube 20 may also be made of, for example, a waterproof material. Here, "waterproof" means that when the inner room temperature shrink tube 20 is in a contracted state, it is able to prevent liquid from entering from the outside to the inside. "Waterproof" means, for example, IPX7 (no water ingress when submerged in water at a depth of 1 m for 30 minutes) as defined in "Degrees of protection provided by enclosures for electrical equipment (IP code)" in JIS C 0920. The material of the inner room temperature shrink tube 20 is, for example, EPDM (ethylene propylene diene rubber).

[0038] Figure 3(a) is a schematic diagram of the outer room temperature shrink tubing 30. Figure 3(b) is a cross-sectional view of the outer room temperature shrink tubing 30. As shown in Figures 1, 3(a), and 3(b), the outer room temperature shrink tubing 30 covers the cable connection part 10 and the inner room temperature shrink tubing 20. The diameter (outer and inner diameter) of the outer room temperature shrink tubing 30 is larger than the diameter of the inner room temperature shrink tubing 20. For example, the axial length (longitudinal direction) of the outer room temperature shrink tubing 30 is longer than the axial length of the inner room temperature shrink tubing 20.

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

[0040] For example, the outer room-temperature shrink tubing 30 may be held in an expanded state around the outer circumference of the diameter-expanding retaining member 33 before covering the cable connection part 10 and the inner room-temperature shrink tubing 20 (before installation, before use). The diameter-expanding retaining member 33, like the diameter-expanding retaining member 23 described above, has a dismantling line 33b formed in the direction in which the axis L2 extends, and can be pulled out as a string-like core ribbon 33c along the dismantling line 33b. The diameter-expanding retaining member 33, like the diameter-expanding retaining member 23 described above, has a first end 33d which is the starting end side for being pulled out as a core ribbon 33c, and a second end 33f which is the ending end side for being pulled out as a core ribbon 33c. Near the first end 33d, an exposed portion 33g is formed where the outer surface of the diameter-expanding retaining member 33 is exposed without the outer room-temperature shrink tubing 30 being installed, and an exposed portion 33g is also formed near the second end 33f. In this way. The shape and material of the diameter-expanding retaining member 33 can be the same as, for example, the shape and material of the diameter-expanding retaining member 23.

[0041] The cable connection section 10 includes, for example, an insulating tube 11, a connector 12, and a semiconducting tape 13. The insulating tube 11 is configured as a cylindrical body having a hollow portion 11b that penetrates the longitudinal direction D1 of the cable 2. The insulating tube 11 includes, for example, an insulating tube body 11c having the hollow portion 11b, a shielding mesh 11d, a water-blocking layer 11f, and a waterproof tube 11g. The insulating tube body 11c is, for example, a one-piece molded product of rubber. An exemplary insulating tube body 11c may include insulating rubber, for example, ethylene propylene rubber or silicone rubber. For example, the insulating tube body 11c includes insulating rubber 11c1 and conductive rubber 11c2. The conductive rubber 11c2 is provided, for example, at each of the ends of the insulating tube body 11c in the longitudinal direction D1, and in the center of the insulating tube body 11c in the longitudinal direction D1. The shielding mesh 11d covers at least a portion of the insulating cylinder body 11c. The water-impermeable layer 11f covers the shielding mesh 11d. For example, at least a portion of the shielding mesh 11d is covered by the outer room-temperature shrink tubing 30.

[0042] The insulating tube 11 covers, for example, the connector 12. Figure 4 is a schematic diagram of the insulating tube 11. As shown in Figure 4, the insulating tube 11 may be held in an expanded state around the outer circumference of the diameter-expanding retaining member 11h before covering the connector 12 (before installation, before use). The diameter-expanding retaining member 11h, like the diameter-expanding retaining member 23 described above, has a dismantling line 11j, and can be pulled out as a core ribbon, which is a string-like body, along the dismantling line 11j. The material of the diameter-expanding retaining member 11h can be the same as the material of the diameter-expanding retaining member 23, for example.

[0043] The connector 12 connects, for example, conductors 2b extending from each of a pair of cables 2 that are facing each other along the longitudinal direction D1. Figure 5 is a perspective view showing an exemplary connector 12. As shown in Figures 1 and 5, the connector 12 is, for example, a sleeve for crimping and connecting a plurality of conductors 2b. An exemplary connector 12 has a cylindrical shape with an outer surface 12f having 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 described above, a screw-in connector (also called a shear bolt connector) may be used as the connector 12. In this case, multiple screw holes communicating with the internal space of the connector body are formed on the outer surface of the cylindrical connector body, and the conductors inside the connector body are pressed together by screwing each bolt into each screw hole. With each of the pair of conductors inserted into the connector body from each opening, each of the multiple bolts is screwed into each screw hole, thereby electrically connecting the pair of conductors 2b to each other. When the cable connection part 10 is equipped with this connector 12, a compression tool can be made unnecessary, and the pair of conductors 2b can be easily connected. The above is an example of the type of connector 12, but the type of connector is not particularly limited. Note that a semiconductive tape 13 is wrapped around the connector 12.

[0045] Figures 6(a) and 6(b) are schematic perspective views showing the shielding section 16 of the cable connection structure 1. Figure 7 is a schematic cross-sectional view showing the layer structure of the cable 2. As shown in Figures 6(a), 6(b), and 7, the cable 2 is constructed by layering the conductor 2b, insulating layer 2c, semiconducting layer 2d, shielding layer 2f, semiconducting layer 2g, water-insulating layer 2h, and cable sheath 2j in this order from the inside radially of the cable 2. The shielding section 16 indicates the area in the shielding layer 2f, semiconducting layer 2g, water-insulating layer 2h, and cable sheath 2j where the piercing terminal 40, grounding wire 50, and grounding spring 60 are provided.

[0046] For example, the shielding section 16 has a portion 17 where the cable sheath 2j and the waterproofing 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 the area where the cable sheath 2j, the waterproofing layer 2h, and the semiconducting layer 2g have been stripped off, exposing 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 waterproofing layer 2h are separated from the shielding layer 2f is the area between a pair of cuts 18 aligned along the circumferential direction D2, and includes the cable sheath 2j and the waterproofing layer 2h peeled back from the shielding layer 2f. The portion 17 has, for example, a three-layer structure of cable sheath 2j, waterproofing layer 2h, and semiconducting layer 2g.

[0047] For example, the shielding section 16 has multiple (for example, two) sections 17 in which the cable sheath 2j and the waterproofing layer 2h are spaced apart from the shielding layer 2f, and the multiple sections 17 are arranged along the circumferential direction D2. For example, a piercing terminal 40 and a grounding wire 50 are installed in each of the multiple sections 17. The piercing terminal 40 and the grounding wire 50 are installed to electrically and mechanically connect the waterproofing layer 2h and the shielding layer 2f to each other and maintain the potential of the waterproofing layer 2h and the shielding layer 2f at the same potential. The piercing terminal 40 is fixed to the section 17 by being pierced through the cable sheath 2j and the waterproofing 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 extended 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 extended portion 52 opposite to the first bent portion 51 (the inner end of the spaced portion 17), and a second extended portion 54 that extends from the second bent portion 53 to the exposed portion 19.

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

[0050] As described above, the grounding wire 50 is installed inside the cable sheath 2j with a Z-shaped bend (for example, a first bend 51 and a second bend 53). The length of the bend of the grounding wire 50 (for example, the length from the first bend 51 to the second bend 53) is, for example, 20 mm or more. This ensures that even if shrink-back of 20 mm or less occurs in the cable sheath 2j, the connection between the waterproofing layer 2h and the shielding layer 2f by the grounding wire 50 can be reliably maintained. Furthermore, even if the relative position of the cable sheath 2j and the shielding layer 2f shifts due to thermal expansion or the like, the bend absorbs this shift, thereby reliably maintaining the electrical and mechanical connection between the waterproofing layer 2h and the shielding layer 2f. In addition, by tightening the grounding wire 50 to the shielding layer 2f with the grounding spring 60, the connection between the shielding layer 2f and the waterproofing layer 2h can be made even stronger.

[0051] Figure 8 is a perspective view showing a piercing terminal 40 to which an exemplary grounding wire 50 is connected. Figure 9(a) is a diagram showing an exemplary piercing terminal 40. Figure 9(b) is a diagram showing an exemplary grounding wire 50. Figure 9(c) is a diagram showing an exemplary grounding spring 60. As shown in Figures 8, 9(a) and 9(b), the piercing terminal 40 may be a termifoil terminal attached to the end of the grounding wire 50. The exemplary piercing terminal 40 comprises a first portion 42 having a plurality of blades 41 that pierce the cable sheath 2j and the waterproofing 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. The first portion 42 is, for example, continuous with the second portion 43 via a bent portion 45, and the second portion 43 is bent via the bent portion 45 to approach the first portion 42.

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

[0054] The first part 42 is located, for example, on the extension of the direction D3 of the connecting part 44. For example, the first part 42 has a rectangular plate shape extending in direction D3 and in direction D4 intersecting direction D3. The first part 42 has blades 41 that pierce the cable sheath 2j and the waterproofing layer 2h. The first part 42 has, for example, a plurality of through holes 42b that penetrate in the thickness direction of the first part 42, with the blades 41 protruding from the edges of the through holes 42b. For example, a plurality (four for example) of blades 41 may protrude from the through holes 42b. For example, the piercing terminal 40 has five blades 41. In this case, one of the five blades 41 may be located in the center of the first part 42, and the remaining four may be arranged in a square shape. Thus, one of the plurality of blades 41 may be located in the center of the first part 42.

[0055] For example, the second portion 43 has a rectangular plate shape. The second portion 43, like the first portion 42, has a plurality of through holes 43b that penetrate in the thickness direction of the second portion 43, and the blade portion 41 may protrude from the edge of the through holes 43b. The second portion 43 has an opposing surface that faces the first portion 42 when it is bent to approach the first portion 42 via the bending portion 45, and for example, the blade portion 41 protrudes from this opposing surface. The number of blade portions 41 on 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, and may be 9 or less, 8 or less, 7 or less, or 6 or less.

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

[0057] For example, the grounding wire 50 may be a flat braided wire (for example, a flat braided copper wire). The length of the grounding wire 50 may be 100 mm or more and 200 mm or less (for example, 150 mm). The cross-sectional area of ​​the grounding wire 50 is 1.25 mm². 2 The above and 14mm 2 The following may also apply. For example, the grounding wire 50 is formed by braiding together multiple strands containing a conductive material. For example, the diameter of the strands is 0.12 mm, and the number of strands constituting the grounding wire 50 is 490, so the cross-sectional area of ​​the grounding wire 50 is 5.54 mm². 2 (=0.0012mm 2 This results in (×490). However, the diameter and number of the strands, as well as the length and cross-sectional area of ​​the grounding 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. When the grounding spring 60 is wrapped around the shielding layer 2f and the grounding wire 50, it exerts an elastic force in the radial direction of the cable 2. In the example described above, an example was described in which the cable connection member 100 comprises an inner room-temperature shrinkable tube 20, an outer room-temperature shrinkable tube 30, a piercing terminal 40, a grounding wire 50, and a grounding spring 60. However, the cable connection member may also comprise a piercing terminal 40, a grounding wire 50, and a grounding spring 60, and the components constituting the cable connection member can be changed as appropriate.

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

[0060] Next, as shown in Figures 10(b) and 10(c), the process of inserting the components into the cable 2 is performed. At this time, the outer room temperature shrink tube 30, which has been expanded by the diameter expansion retaining member 33, and the inner room temperature shrink tube 20, which has been expanded by the diameter expansion retaining member 23, are each inserted into the pair of cables 2. Then, the insulating tube 11, which has been expanded by the diameter expansion retaining member 11h, is inserted into one of the pair of cables 2.

[0061] Then, as shown in Figure 11(a), the process of attaching the connector 12 is carried out. Specifically, each of the pair of conductors 2b is inserted into the respective openings 12c of the connector 12, and the connector 12 is crimped. This tightens the pair of conductors 2b with the connector 12 and electrically connects the pair of cables 2 to each other.

[0062] After connecting the pair of cables 2 with the connector 12, the process of wrapping the semiconductive tape 13 around it is performed as shown in Figure 11(b). At this time, the semiconductive tape 13 is wrapped around the connector 12. For example, the entire connector 12 is covered with the semiconductive tape 13.

[0063] Next, as shown in Figures 12(a) and 12(b), the process of attaching the insulating tube 11 is performed. Specifically, the insulating tube 11 that was inserted into the cable 2 is moved, and for example, the core ribbon of the diameter-expanding retaining member 11h is pulled out and the semiconductive tape 13 and the pair of cables 2 are tightened with the insulating tube 11. After that, shielding is performed on each of the ends of the insulating tube 11 in the longitudinal direction D1 to form the shielding section 16.

[0064] Figures 6(a), 6(b), 13, and 14, mentioned above, show the specific procedure for forming the shielding section 16. First, as shown in Figure 13, the cable sheath 2j, water-insulating layer 2h, and semiconducting layer 2g of the cable 2 are stripped from both ends of the insulating cylinder 11 in the longitudinal direction D1 to form exposed sections 19 where the shielding layer 2f is exposed.

[0065] Next, cuts 18 are made in the cable sheath 2j and the waterproof layer 2h (waterproof layer 2h laminated with a semiconductive layer 2g) of the cable 2 located on the opposite side of the exposed portion 19 from the insulating cylinder 11, and the cable sheath 2j and waterproof layer 2h are peeled back to form a portion 17 in which the cable sheath 2j and waterproof layer 2h are separated from the shielding layer 2f, thereby exposing the shielding layer 2f (step of exposing the shielding layer). At this time, a pair of cuts 18 are made along the circumferential direction D2 of the cable 2, and the portion between the pair of cuts 18 is peeled back to form a portion 17 separated from the shielding layer 2f. For example, multiple (two as an example) separated portions 17 are formed.

[0066] Meanwhile, the ground wire 50 is connected to the piercing terminal 40 (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 ground wire 50 is connected to the piercing terminal 40 by crimping the connecting portion 44 into which the ground wire 50 is inserted. Then, the piercing terminal 40 is thrust 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 thrust into the cable sheath 2j and waterproof layer 2h of the portion 17. Specifically, with the connecting portion 44 of the piercing terminal 40 positioned at the end of the portion 17 in the longitudinal direction D1, the portion 17 is sandwiched between the first portion 42 and the second portion 43, and the piercing terminal 40 is fixed to the portion 17 by thrusting the blade portion 41 into the portion 17.

[0067] After inserting the piercing terminal 40 into the portion 17 and fixing the piercing terminal 40, as shown in Figure 6(a), the grounding wire 50 extending from the piercing terminal 40 is bent so that it follows the inner side 17b of the spaced portion 17 and the shielding layer 2f (step of bending the grounding wire). At this time, a bent portion that bends in a Z shape is formed. As a specific example, the grounding wire 50 extending from the connecting portion 44 is folded back so that it follows the inner side 17b of the portion 17 to form a first bent portion 51 (step of forming the first bent portion), and the grounding wire 50 is followed by the inner side 17b of the portion 17 to form a first extended portion 52 (step of forming the first extended portion). Subsequently, a second bent portion 53 is formed by bending the first extended portion 52 from the end opposite to the first bent portion 51 so as to follow the shielding layer 2f (step of forming the second bent portion), and a second extended portion 54 is formed by extending the grounding wire 50 from the second bent portion 53 along the shielding layer 2f (step of forming the second extended portion).

[0068] As described above, the process of bending the grounding wire 50 is performed, for example, for each of the multiple spaced-apart sections 17. Then, as shown in Figures 6(a) and 6(b), the grounding spring 60 is wrapped around the grounding wire 50 extending along the shielding layer 2f (the process of wrapping the grounding spring). At this time, the grounding spring 60 is wrapped around the grounding wire 50 extending from the bent section. As a specific example, the grounding spring 60 is installed by wrapping a tape-shaped grounding spring 60 around the grounding wire 50 and fixing it in place. For example, the grounding spring 60 is wrapped around multiple grounding wires 50.

[0069] After wrapping the grounding spring 60, as shown in Figure 14, the tape T is wrapped around the cable after confirming the conductivity between the waterproofing layer 2h and the shielding layer 2f. Then, as shown in Figure 15(a), the process of attaching the inner room temperature shrink tubing 20 is performed. Specifically, the inner room temperature shrink tubing 20 that was inserted into each of the pair of cables 2 is moved to one side and the other side of the cable connection part 10 (adjacent positions of the cable connection part 10). Then, the core ribbon 23c of the diameter expansion holding member 23 of each inner room temperature shrink tubing 20 is pulled out and each inner room temperature shrink tubing 20 is shrunk, thereby tightening one side and the other side of the cable connection part 10 with each inner room temperature shrink tubing 20.

[0070] Next, as shown in Figure 15(b), the process of attaching the outer room temperature shrink tubing 30 is performed. At this time, the outer room temperature shrink tubing 30 that was inserted into each of the pair of cables 2 is moved to a position that covers the cable connection part 10 and the inner room temperature shrink tubing 20. Specifically, each outer room temperature shrink tubing 30 is moved to a position that covers at least a part of the cable connection part 10 and at least a part of the inner room temperature shrink tubing 20. Then, the core ribbon 33c of the diameter expansion holding member 33 of each outer room temperature shrink tubing 30 is pulled out to shrink each outer room temperature shrink tubing 30. As a result, each outer room temperature shrink tubing 30 covers one side of the cable connection part 10 in the longitudinal direction D1 and the inner room temperature shrink tubing 20, and the other side of the cable connection part 10 in the longitudinal direction D1 and the inner room temperature shrink tubing 20, respectively. After that, the series of steps of connecting the pair of cables 2 to each other is completed.

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

[0072] By electrically connecting the shielding layer 2f to the waterproofing layer 2h, the potential of the waterproofing layer 2h and the potential of the shielding layer 2f can be made the same, thereby suppressing the induction of voltage. Consequently, discharge associated with voltage induction can be suppressed. Furthermore, by connecting the waterproofing layer 2h and the shielding layer 2f with the piercing terminal 40 and the grounding wire 50, soldering can be eliminated, thereby increasing the reliability of the connection. Since the grounding wire 50 with the piercing terminal 40 can be connected to the shielding layer 2f by piercing the piercing terminal 40, the number of parts can be reduced, and the installation of the cable connection structure 1 can be made easier. Moreover, since the grounding wire 50 is arranged in a bent state along the cable sheath 2j, the inside 17b of the waterproofing layer 2h, and the shielding layer 2f, even if thermal expansion occurs, the bent portion can follow this thermal expansion. Consequently, even if thermal expansion occurs, the connection between the waterproofing layer 2h and the shielding layer 2f can be maintained more reliably, thereby further increasing the reliability of the connection.

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

[0074] The grounding wire 50 may have a mesh structure. In this case, the elasticity of the grounding wire 50 can be increased, making it easier to accommodate thermal expansion and other factors. Therefore, the reliability of the connection can be further improved.

[0075] The cable connection method according to this embodiment may include a step of wrapping a grounding spring 60 around the grounding wire 50 that extends from the bent portion along the shielding layer 2f. In this case, the grounding wire 50 that contacts the shielding layer 2f can be fixed by wrapping it with the grounding spring 60. Therefore, the reliability of the connection can be further improved without using solder. Furthermore, since specialized tools such as soldering irons are not required, high-quality connection reliability can be ensured even without skilled personnel.

[0076] The length of the grounding wire 50 may be 100 mm or more and 200 mm or less. When the length of the grounding 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 grounding wire 50 is 200 mm or less, the grounding wire 50 can be easily fixed to the shielding layer 2f.

[0077] The cross-sectional area of the grounding wire 50 may be 1.25 mm 2 or more and 14 mm 2 or less. When the cross-sectional area of the grounding wire 50 is 1.25 mm 2 or more, the strength of the grounding wire 50 can be increased. When the cross-sectional area of the grounding wire 50 is 14 mm 2 or less, the handling property of the grounding wire 50 can be further improved.

[0078] In the step of fixing the piercing terminal 40, a plurality (for example, two) of piercing terminals 40 may be fixed. In this case, since a plurality of piercing terminals 40 are fixed, even if a connection failure occurs in one piercing terminal 40, the connection in other piercing terminals 40 is maintained. Therefore, the reliability of the connection can be further increased and the safety can be improved.

[0079] The piercing terminal 40 may have a blade portion 41 that pierces into a portion 17 spaced apart from the shielding layer 2f of the cable sheath 2j and the water shielding layer 2h, and the number of the blade portions 41 may be 2 or more and 10 or less. When the number of the blade portions 41 is 2 or more, the connection of the piercing terminal 40 to the cable sheath 2j and the water shielding layer 2h can be strengthened. When the number of the blade portions 41 is 10 or less, the configuration of the piercing terminal 40 can be simplified and the connection by the piercing terminal 40 can be easily performed.

[0080] Embodiments of the cable connection method, cable connection structure, and cable connection member relating to this disclosure have been described above. However, this disclosure is subject to various modifications without altering the gist of the claims. Specifically, the shape, size, number, and arrangement of each component of the cable connection structure and cable connection member, as well as the content and sequence of steps of the cable connection method, can be appropriately modified without altering the gist of the disclosure.

[0081] For example, in the above-described embodiment, an example was described in which the cable connection member comprises a piercing terminal 40, a grounding wire 50, and a grounding spring 60. However, the cable connection member may comprise at least one of the piercing terminal 40, the grounding wire 50, and the grounding spring 60, and the components constituting the cable connection member can be changed as appropriate.

[0082] The piercing terminal according to this disclosure is a piercing terminal attached to a grounding wire and may be inserted into a portion of the cable that is spaced apart from the cable sheath and the shielding layer of the waterproofing layer. The grounding wire according to this disclosure may be flat and braided in shape and attached to a piercing terminal inserted into a portion of the cable sheath and the shielding layer that is spaced apart from the shielding layer, and may be bent to be on the inside of the spaced portion and along the shielding layer. The grounding spring according to this disclosure may be bent to be on the inside of the portion of the cable sheath and the waterproofing layer that is spaced apart from the shielding layer and wrapped around the grounding wire extending from the shielding layer.

[0083] In the embodiment described above, an example was explained in which the grounding wire 50 is fixed in contact with the shielding layer 2f by wrapping a grounding spring 60 around the grounding wire 50. However, the means for fixing the grounding wire 50 in contact with the shielding layer 2f is not limited to the grounding spring 60. For example, the grounding wire 50 may be fixed in contact with the shielding layer 2f by wrapping a braided wire around the grounding wire 50 extending into 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 given in which the grounding wire 50 extending from the piercing terminal 40 is bent so as to follow the inner side 17b of the spaced portion 17 and the shielding layer 2f. In this case, for example, if the grounding wire 50 is made of an expandable material, the grounding wire 50 may be bent while it is contracted. In this case, the ability of the grounding wire 50 to follow thermal expansion and the like can be further improved. As described above, in the above-described embodiment, an example was given in which the grounding wire 50 is a flat braided wire. However, the grounding wire may be made of something other than a flat braided wire, for example, a braided wire, a flat metal foil, or a metal wire.

[0085] In the embodiments described above, cable 2, which is a power cable with a rating of 66kV or higher, was used as an example. However, the cable connection method, cable connection structure, and cable connection member according to this disclosure may also be applied to power cables with a rating of less than 66kV.

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

[0087] The shielding section 76 differs from the shielding section 16 described above in that the grounding wire 50 extending from the piercing terminal 40 does not run along the inside 17b of the spaced portion 17. In the shielding section 76, the grounding wire 50 has a first bent portion 51 that extends from the piercing terminal 40 and bends inward from the piercing terminal 40 (radially inward from the cable 2), a second bent portion 53 that extends longitudinally D1 from the first bent portion 51 and bends inside the piercing terminal 40, and a second extended portion 54 that extends from the second bent portion 53 to the exposed portion 19. The second bent portion 53 is located, for example, below the piercing terminal 40. The second extended portion 54 extends longitudinally D1 in the exposed portion 19, and a grounding spring 60 is wrapped around this extended portion. In the modified grounding wire 50, the Z-shaped bent portions (first bent portion 51 and second bent portion 53) are exposed on top of the shielding layer 2f.

[0088] In the modified cable connection method, after fixing the piercing terminal 40 to the end of the portion 17 where the cable sheath 2j and the waterproof layer 2h are separated from the shielding layer 2f, the grounding wire 50 extending from the piercing terminal 40 is folded back to form a first bend 51 (step of forming the first bend). Then, a second bend 53 is formed at the lower part of the piercing terminal 40 so as to bend along the shielding layer 2f (step of forming the second bend). Then, the grounding wire 50 is extended from the second bend 53 along the shielding layer 2f to form a second extension 54 (step of forming the second extension). Then, a grounding spring 60 is wrapped around the second extension 54 that extends along the shielding layer 2f (step of wrapping the grounding spring). After wrapping the grounding spring 60, the conductivity between the waterproof layer 2h and the shielding layer 2f is confirmed and then tape T is wrapped around it.

[0089] Even with the modified cable connection structure and cable connection method described above, the same effects and advantages as those of the shielding section 16 described above can be obtained. In the modified examples described above, an example was given in which the Z-shaped bend (second bend 53) of the grounding wire 50 is located inside the piercing terminal 40 (radially inside the cable 2). However, as shown in Figure 17, the shielding section 86 may also be one in which the Z-shaped bend of the grounding wire 50 is not inside the piercing terminal 40 (exposed in the shielding layer 2f). In the shielding section 86, the grounding wire 50 has a first bend 51 that extends from the piercing terminal 40 and bends inward (towards the shielding layer 2f) at a position spaced apart from the piercing terminal 40, a second bend 53 that extends from the first bend 51 toward the piercing terminal 40 and bends inward at a position spaced apart from the piercing terminal 40, and a second extending section 54 that extends from the second bend 53 to the exposed section 19. Even in the case of this shielding processing unit 86, the same effects and advantages as those of the shielding processing units 16 and 76 described above can be obtained.

[0090] (Examples) Next, embodiments 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 embodiments. First, in the embodiments, as shown in Figures 9(a), 9(b), and 9(c), a piercing terminal 40, a grounding wire 50, and a grounding spring 60 were prepared. In these embodiments, the piercing terminal 40 is a piercing connector (Termifoil manufactured by Tyco), and the cross-sectional area of ​​the grounding wire 50 is 5.5 mm². 2 The length of the grounding wire 50 was set to 150 mm. A constant force spring manufactured by 3M was used as the grounding spring 60.

[0091] As shown in Figures 6(a) and 6(b), the piercing terminals 40, grounding wires 50, and grounding springs 60 were installed on a 66kV cable 2. Specifically, two portions 17 were formed in the cable 2, separated from the shielding layer 2f of the cable sheath 2j and the waterproofing layer 2h. Piercing terminals 40 were inserted into each of these portions 17, and the grounding wires 50 were bent to follow the inside 17b of the portions 17 and the shielding layer 2f. Then, the grounding springs 60 were wrapped around the two grounding wires 50 extending through the shielding layer 2f, and tape T was wrapped around them as shown in Figure 14 to confirm the conductivity of the waterproofing layer 2h and the shielding layer 2f. The cable connection structure according to the embodiment was formed through the above steps. In contrast, the cable connection structure of the comparative example was formed as follows.

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

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

[0094] As a result of the above experiment, in the comparative example's cable connection structure using soldering to flat braided wire, the solder connection came undone in all three samples after five reciprocating movements. In contrast, in the example's cable connection structure using the piercing terminal 40 and grounding wire 50, the connection did not come undone in any of the three samples even after five reciprocating movements. Therefore, it was found that in the example using the piercing terminal 40 and grounding wire 50, high followability can be obtained even if reciprocating movement such as thermal shrinkage occurs in the cable 2, thereby improving connection reliability. In other words, in the example, since the excess length of the grounding wire 50 connecting the waterproofing layer 2h and the shielding layer 2f is folded and housed inside the cable sheath 2j, it was found that even if shrink-back of the cable sheath 2j or core movement of the cable 2 (movement of the part inside the shielding layer 2f) occurs, the connection can be reliably maintained due to high followability.

[0095] Next, another example of the structure of the grounding wire in the cable connection structure 1 according to the embodiment will be described with reference to Figure 18. In the cable connection structure 1, in addition to the grounding wire 50 (which may be called the waterproof layer grounding wire 50 for distinction) shown in Figure 14, Figure 18 also shows a shielding layer grounding wire 90. The waterproof layer grounding wire 50 is a grounding wire for grounding the waterproof layer 2h, while the shielding layer grounding wire 90 is a grounding wire for grounding the shielding layer 2f. The shielding layer grounding wire 90 is used when it is desired to lower the potential of the shielding layer 2f. For example, in long-length lines, the potential of the shielding layer 2f of the cable 2 rises, so it is used when a grounding wire is drawn out at an intermediate connection point and connected to a grounding electrode. Figure 18 shows both the waterproof layer grounding wire 50 and the shielding layer grounding wire 90, but it is also possible to have only one of them. That is, (1) if a cable with a waterproof layer is used and there is no need to lower the potential of the cable shielding layer, the waterproof layer grounding wire 50 alone is sufficient. (2) If a cable equipped with a waterproofing layer is used and it is desired to lower the potential of the cable shielding layer, both the waterproofing layer grounding wire 50 and the shielding layer grounding wire 90 are used. (3) If a cable without a waterproofing layer is used and it is desired to lower the potential of the cable shielding layer, the shielding layer grounding wire 90 alone is sufficient. In Figure 19 and subsequent figures, the waterproofing layer grounding wire 50 is omitted, but the explanation will cover both cases (2) and (3) in common.

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

[0097] The first grounding lead-out section 70 is the part where the shielding layer grounding wire 90 connects to the shielding layer 2f of the cable 2, and the shielding layer grounding wire 90 is held down by the grounding spring 60. The inner room temperature shrink tube 20 is a tube with a built-in waterproofing layer, and the first grounding lead-out section 70 is provided inside the waterproofing layer of the inner room temperature shrink tube 20. For example, the waterproofing layer of the inner room temperature shrink tube 20 is a metal foil made of a metal material such as aluminum. In this case, if stress concentrates in the waterproofing layer of the inner room temperature shrink tube 20, there is a possibility that a hole may form in the waterproofing layer. Therefore, in order to prevent stress from concentrating in the waterproofing layer of the inner room temperature shrink tube 20, the first grounding lead-out section 70 is made flat without any irregularities.

[0098] The second grounding lead-out section 80 is the portion that includes the shielding layer grounding wire 90 protruding from the inner room temperature shrinkable tube 20, and is the portion where the shielding layer grounding wire 90 connects to the terminal 82 at a position extending longitudinally from the first grounding lead-out section 70 of the cable 2. The second grounding lead-out section 80 is provided with a grounding wire lead-out protection section 81 that protects the led-out shielding layer grounding wire 90, a terminal 82 connected to the shielding layer grounding wire 90, and a metal member 83 extending from the terminal 82 on the opposite side from the shielding layer grounding wire 90. As an example, the grounding wire lead-out protection section 81 includes a tape 81b that covers the exposed shielding layer grounding wire 90 and is attached to the terminal 82, and a waterproof tube 81c that covers 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 that does not have a water-impermeable layer. As an example, the waterproof tube 81c is a room temperature shrinkable tube.

[0099] The portion of the second grounding lead-out section 80 that does not have the inner room temperature shrink tubing 20 corresponds to a portion where stress on the water-insulating layer of the inner room temperature shrink tubing 20 does not need to be considered, and therefore may have irregularities. The terminal 82 and the metal member 83 are located away from the inner room temperature shrink tubing 20. For example, the terminal 82 is joined to the metal member 83 by a bolt and nut 84. As an example, the portion of the cable 2 where the terminal 82 and the bolt and nut 84 are provided protrudes.

[0100] The metal member 83 is made of, for example, copper. For example, the metal member 83 is plate-shaped. For example, the metal member 83 has a connecting portion 83b that is connected to the terminal 82 and covered by the grounding wire outlet protection portion 81, and an extending portion 83c that is not covered by the grounding wire outlet protection portion 81 and extends from the connecting portion 83b outward from the grounding wire outlet protection portion 81. The connecting portion 83b is the part of the metal member 83 on the terminal 82 side and corresponds to the part that is connected to the terminal 82 via a 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 outlet protection portion 81 (tape 81b), and between the connection portion 83b and the cable 2. The connection portion 83b may also be spaced apart from the cable 2. The extending portion 83c extends diagonally outward in the radial direction of the cable 2 as it moves away from the connection portion 83b, for example.

[0102] Next, the assembly method of the cable connection structure 1, which includes a first grounding lead-out section 70 and a second grounding lead-out section 80, will be described. First, as shown in Figure 20, with the insulating cylinder 11 of the cable connection section 10 attached to the cable 2, the shielding layer grounding wire 90 is fixed to the shielding layer 2f of the cable 2 by the grounding spring 60 and the shielding layer grounding wire 90 is pulled out (step of forming the first grounding lead-out section). Then, a bent section P is formed. Section P is an excess length that allows the shielding layer grounding wire 90 to follow when the cable 2 expands and contracts in the longitudinal direction due to thermal expansion and contraction.

[0103] As shown in Figure 21, an inner room-temperature shrink tubing 20 is installed so as to cover the bent portion P of the shielding layer grounding wire 90. Then, a terminal 82 is connected to the portion of the shielding layer grounding wire 90 that extends from the inner room-temperature shrink tubing 20, and the terminal 82 is connected to the metal member 83 with a bolt and nut 84 (step of forming the second grounding lead-out portion). At this time, putty material 85 may be applied between the metal member 83 and the cable 2.

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

[0105] Next, a modified example of the cable connection structure comprising the first grounding lead-out section 70 and the second grounding lead-out section 80 will be described. In the following, explanations that overlap with the above will be omitted as appropriate. As shown in Figure 23, the modified cable connection structure 1A includes a grounding wire lead-out protection section 81A that is different from the grounding wire lead-out protection section 81. The grounding wire lead-out protection section 81A differs from the grounding wire lead-out protection section 81 in that it does not have a waterproof tube. For example, the grounding wire lead-out protection section 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 modification of the cable connection structure comprising the first grounding lead-out portion 70 and the second grounding lead-out portion 80 will be described. As shown in Figure 24, the modified cable connection structure 1B does not have a terminal 82 and includes a metal member 83B that is different from the metal member 83. In addition to the connection portion 83b and extension portion 83c described above, the metal member 83B has a terminal portion 83d. The terminal portion 83d is located at the end of the connection portion 83b on the shielding layer grounding wire 90 side and functions as a terminal to which the shielding layer grounding wire 90 is connected.

[0107] As shown in Figures 24 and 25, for example, the terminal portion 83d of the metal member 83B is cylindrical and protrudes from the plate-shaped connecting portion 83b. In this case, the shielding layer grounding wire 90 is inserted into the inside of the cylindrical terminal portion 83d and crimped inside the terminal portion 83d, thereby connecting the shielding layer grounding wire 90 to the metal member 83B. Thus, in the modified cable connection structure 1B, the terminal portion 83d integrated with the metal member 83 is connected to the shielding layer grounding wire 90 instead of the terminal 82, making the bolt and nut 84 unnecessary and reducing the number of parts.

[0108] In the cable connection structures 1, 1A, and 1B described above, which include a first grounding lead-out section 70 and a second grounding lead-out section 80, the shielding layer grounding wire 90 has a first grounding lead-out section 70 that connects to the shielding layer 2f, and a second grounding lead-out section 80 that connects to a terminal at a position extending from the first grounding lead-out section 70 in the longitudinal direction of the cable 2. The first grounding lead-out section 70 is provided inside the water-insulating layer of the inner room-temperature shrinkable tube 20, which is a water-insulating tube. Therefore, the occurrence of irregularities in the first grounding lead-out section 70 can be suppressed, and wrinkles in the water-insulating layer of the inner room-temperature shrinkable tube 20 can be suppressed. As a result, holes in the water-insulating layer can be more reliably suppressed. In addition, the second grounding lead-out section 80 located outside the inner room-temperature shrinkable tube 20 is covered with grounding wire lead-out protection sections 81 and 81A, thereby protecting the second grounding lead-out section 80 located outside the inner room-temperature shrinkable tube 20.

[0109] The above describes various examples of cable connection structures equipped with a first grounding outlet and a second grounding outlet. However, the structures of the first and second grounding outlets are not limited to the examples described above and can be modified in various ways. For example, the above example described a second grounding outlet 80 equipped with a grounding wire outlet protection part 81, a terminal 82, a metal member 83, a bolt and nut 84, and putty material 85. However, the components constituting the second grounding outlet are not limited to the above example and can be changed as appropriate. The same applies to the first grounding outlet. [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 part, 11…Insulating tube, 11b…Hollow part, 11c1…Insulating rubber, 11c2…Conductive rubber, 11d…Shielding mesh, 11f…Waterproof layer, 11g…Waterproof tube, 11h…Expanding retaining member, 11j…Disassembly wire, 12…Connector, 12c…Opening ,12f...outer surface, 13...semiconductive tape, 16,76,86...shielding section, 17...separated section, 17b...inside, 18...cut, 19...exposed section, 20...inner room temperature shrink tubing, 23...diameter expansion retaining member, 23b...disassembly line, 23c...core ribbon, 23d...first end, 23f...second end, 23g...exposed section, 30...outer room temperature shrink tubing, 33...diameter expansion retaining member, 33b...disassembly line, 33c...core ribbon, 33d...first 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 outlet protection part, 81b...Tape, 81c...Waterproof tube, 81d...Self-fusing tape, 81f...Tape, 82...Terminal, 83,83B...Metal member, 83b...Connection part, 83c...Extending part, 83d...Terminal part, 84...Bolt and nut, 85...Putty material, 90...Shielding layer grounding wire, 100...Cable connection member, B...Boundary part, D1...Longitudinal direction, D2...Circumferential direction, D3,D4...Direction, L1,L2...Axis, T...Tape.

Claims

1. A cable connection structure provided for a cable having a watertight layer located inside the cable sheath and a shielding layer located inside the watertight layer, Grounding wire and A fixing member is attached to the grounding wire and is inserted into the portion of the cable sheath and the waterproof layer that is spaced apart from the shielding layer, Equipped with, The grounding wire is connected to the shielding layer in a bent state. A pressing member is wrapped around the grounding wire extending from the bent portion along the shielding layer, A room-temperature shrinkable tube covering the aforementioned cable, Equipped with, The fixing member is inserted into the cable sheath and the waterproof layer, thereby connecting the grounding wire to the waterproof layer inside the cable sheath. The pressing member tightens the grounding wire to the shielding layer in the exposed portion where the cable sheath and the waterproofing layer are separated from the shielding layer and the shielding layer is exposed. Cable connection structure.

2. The aforementioned grounding wire has a flattened shape. The cable connection structure according to claim 1.

3. The aforementioned grounding wire has a mesh-like structure. The cable connection structure according to claim 1 or 2.

4. It has a shielding layer grounding wire drawn out from the shielding layer, The shielding layer grounding wire has a first grounding lead-out portion that connects to the shielding layer, and a second grounding lead-out portion that connects to a terminal at a position extending from the first grounding lead-out portion in the longitudinal direction of the cable. The first grounding outlet is located inside the waterproof layer-embedded tube that covers the cable, and the second grounding outlet is located outside the waterproof layer-embedded tube. The device includes a grounding wire outlet protection section that covers the second grounding outlet section, The cable connection structure according to any one of claims 1 to 3.

5. A cable connection method for a cable having a water-impermeable layer located inside the cable sheath and a shielding layer located inside the water-impermeable layer, The process of stripping the cable sheath and the waterproofing layer and separating the cable sheath and the waterproofing layer from the shielding layer thereby exposing the shielding layer, The process involves inserting a fixing member attached to the ground wire into a portion of the cable sheath and the waterproof layer that is spaced apart from the shielding layer, thereby fixing the fixing member to the portion of the cable sheath and the waterproof layer that is spaced apart from the shielding layer, A step of connecting the grounding wire extending from the fixing member to the shielding layer in a bent state, A step of wrapping a pressing member around the grounding wire that extends from the bent portion along the shielding layer, After wrapping the pressing member, the process involves attaching a room-temperature shrinkable tube to cover the cable, Equipped with, The fixing member is inserted into the cable sheath and the waterproof layer, thereby connecting the grounding wire to the waterproof layer inside the cable sheath. The pressing member tightens the grounding wire to the shielding layer in the exposed portion where the cable sheath and the waterproofing layer are separated from the shielding layer and the shielding layer is exposed. Cable connection method.

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