A high voltage cable joint

Abstract

The application discloses a high-voltage cable intermediate joint, and belongs to the technical field of cable joints. The high-voltage cable intermediate joint comprises, from inside to outside, a jointing pipe, a semi-conductive filling layer, an inner semi-conductive pipe, an insulating filling layer, an outer shielding cylinder, a copper mesh, an inner sheath, an armored belt and an outer sheath. The inner wall of the inner semi-conductive pipe is sealingly connected with the insulating layers of two high-voltage cables at both ends, and the inner wall of the outer shielding cylinder is sealingly connected with the main shielding layers of the two high-voltage cables at both ends. The curved side walls of the inner semi-conductive pipe and the outer shielding cylinder are both provided with connecting seams. The connecting seams comprise first connecting surfaces and second connecting surfaces. The first connecting surfaces are provided with convex edges, and the second connecting surfaces are provided with convex bosses. The convex bosses are detachably connected with the convex edges through two connecting pieces. The connecting pieces are provided with filling channels which are in communication with the inner cavities of the inner semi-conductive pipe or the outer shielding cylinder. The high-voltage cable intermediate joint with the above structure is beneficial to improving the connection quality of the two high-voltage cables.

Description

Technical Field

[0001] This invention belongs to the field of cable joint technology, and particularly relates to a high-voltage cable intermediate joint. Background Technology

[0002] High-voltage cables are a type of power cable, referring to cables used to transmit power between 1kV and 1000kV, primarily used for power transmission and distribution. The structure of a power cable can be broadly divided into three parts: the conductor, the insulating shielding layer, and the protective layer. The main function of a high-voltage cable joint is to connect the ends of two high-voltage cables, ensuring smooth power transmission while guaranteeing the stability and safety of the power transmission.

[0003] When using high-voltage cable intermediate joints, the splice tube must first be crimped between the two core ends. Then, from the inside out, the inner semiconductive layer, inner shielding layer, insulation layer, outer shielding layer, copper mesh, inner sheath, armor, and outer sheath must be restored in sequence. In existing technologies, the inner semiconductive layer and outer shielding layer are often constructed by wrapping semiconductive tape. However, this wrapping installation process may present the following problems, severely affecting the quality of the intermediate joint and resulting in inconsistent product quality: 1. Human error may cause the wrapping spacing to fail to meet standards; 2. The semiconductive tape may fall off and cause dirt, or other external environmental factors may cause impurities to adhere to the semiconductive tape.

[0004] To solve the above problems, a new type of high-voltage cable intermediate joint is needed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-voltage cable intermediate joint, which is beneficial to improving the connection quality of two high-voltage cables.

[0006] To achieve the above objectives, the present invention provides a high-voltage cable intermediate joint, comprising, from the inside out, a splicing tube, a semi-conductive filling layer, an inner semi-conductive tube, an insulating filling layer, an outer shielding cylinder, a copper mesh, an inner sheath, an armor tape, and an outer sheath. The inner walls of the inner semi-conductive tube are respectively sealed to the insulation layers of two high-voltage cables at both ends. The inner walls of the outer shielding cylinder are respectively sealed to the main shielding layers of two high-voltage cables at both ends. Both the inner semi-conductive tube and the outer shielding cylinder have connecting seams on their curved sidewalls. Each connecting seam includes a first connecting surface and a second connecting surface. The first connecting surface has a protruding edge extending from the outer wall of the curved sidewall, and the second connecting surface has a boss extending from the inner wall of the curved sidewall. The boss is detachably connected to the protruding edge via two connectors. Each connector has a filling channel communicating with the inner cavity of the inner semi-conductive tube or the outer shielding cylinder.

[0007] Preferably, the connector includes a threaded rod and a sealing block fixedly connected at the top and bottom. The top end of the threaded rod is provided with a tightening nut. The boss is provided with a threaded hole adapted to the structure of the threaded rod. The sealing block covers the port of the threaded hole near the inner cavity. The protruding edge is provided with a through hole adapted to the structure of the threaded rod. The filling channel penetrates the connector along the central axis of the connector.

[0008] Preferably, a sealing cap is threaded to the end of the threaded rod away from the sealing block.

[0009] Preferably, the curved outer wall of the semiconductive tube is provided with an upper receiving groove corresponding to the sealing cap and the tightening nut, the curved inner wall of the semiconductive tube is provided with a lower receiving groove corresponding to the sealing block, the top surface of the tightening nut is provided with a first slot, and the top surface of the sealing cap is provided with a second slot.

[0010] Preferably, both ends of the inner wall of the inner semiconducting tube are provided with grooves coaxially arranged with the inner semiconducting tube, the end faces of the two grooves are respectively in contact with the end planes of the insulation layers of the two high-voltage cables, and the curved inner walls of the two grooves are respectively in contact with the curved outer walls of the insulation layers of the two high-voltage cables.

[0011] Preferably, a highly elastic inner shielding tube is attached to the curved outer wall of the inner semiconducting tube, and a highly elastic outer shielding tube is attached to the outer shielding cylinder.

[0012] Preferably, the two ends of the inner semiconducting tube are connected to the insulation layers of the two high-voltage cables by a constant force spring.

[0013] Preferably, a stress cone is fixedly connected to the main shielding layer of the high-voltage cable, and the peeling fault between the main shielding layer and the insulation layer of the high-voltage cable is correspondingly located at the middle of the connection port of the stress cone.

[0014] Preferably, the two ends of the splice tube are respectively crimped to the core ends of the two high-voltage cables.

[0015] Therefore, the high-voltage cable intermediate joint of the present invention with the above-described structure has the following beneficial effects:

[0016] 1. The connector on the inner semiconductive tube can not only realize the installation of the inner semiconductive tube between the insulation layers of two high-voltage cables, but also realize the filling of the semiconductive filling layer through the filling channel on the connector. Compared with the existing technology of wrapping semiconductive tape, it avoids the problem of the semiconductive tape wrapping spacing not meeting the standard or being contaminated, and can realize the uniformity of product quality.

[0017] 2. The use of the sealing block, threaded rod and nut on the connector can ensure the seal between the connector and the inner semiconducting tube. The use of the threaded rod and threaded hole can facilitate the connection between the flange and the boss.

[0018] 3. The groove can increase the stability of the inner semiconducting tube when installed between the insulation layers of two high-voltage cables.

[0019] 4. The outer shielding cylinder is filled with an insulating filler layer, and the insulating filler layer contains a stress cone that is fixedly connected to the main shielding layer of the high-voltage cable, which can increase the stability of the outer shielding cylinder and the insulating filler layer.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of an embodiment of the inner semiconductive tube in a high-voltage cable intermediate joint according to the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of an embodiment of the inner semiconducting tube in a high-voltage cable intermediate joint according to another perspective of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of a connector in a high-voltage cable intermediate joint according to an embodiment of the present invention;

[0024] Figure 4 This is a cross-sectional view of an embodiment of a high-voltage cable intermediate joint according to the present invention.

[0025] In the diagram: 1. Splicing tube; 2. Semiconductor filling layer; 3. Inner semiconductor tube; 4. Insulating filling layer; 5. Outer shielding tube; 6. Copper mesh; 7. Inner sheath; 8. Armor tape; 9. Outer sheath; 10. Insulation layer of high-voltage cable; 11. Main shielding layer of high-voltage cable; 12. Connecting seam; 13. Raised edge; 14. Boss; 15. Connector; 151. Threaded rod; 152. Sealing block; 153. Tightening nut; 16. Filling channel; 17. Core of high-voltage cable; 18. Copper shield of high-voltage cable; 19. Inner sheath of high-voltage cable; 20. Armoring layer of high-voltage cable; 21. Outer sheath of high-voltage cable; 22. Sealing cap; 23. First slot; 24. Second slot; 25. Groove; 26. High-elasticity inner shielding tube; 27. High-elasticity outer shielding tube; 28. Stress cone. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example

[0029] Reference Figure 1-4 As shown in the figure, this embodiment provides a high-voltage cable intermediate joint, including a splicing tube 1, a semi-conductive filling layer 2, an inner semi-conductive tube 3, an insulating filling layer 4, an outer shielding cylinder 5, a copper mesh 6, an inner sheath 7, an armor tape 8, and an outer sheath 9 arranged sequentially from the inside to the outside. The inner walls of the inner semi-conductive tube 3 are respectively sealed to the insulation layers 10 of two high-voltage cables, and the inner walls of the outer shielding cylinder 5 are respectively sealed to the main shielding layers 11 of two high-voltage cables. Both the inner semi-conductive tube 3 and the outer shielding cylinder 5 have connecting seams 12 on their curved sidewalls. The connecting seams 12 include a first connecting surface and a second connecting surface. The first connecting surface has a protrusion 13 extending from the outer wall of the curved sidewall, and the second connecting surface has a boss 14 extending from the inner wall of the curved sidewall. The boss 14 is detachably connected to the protrusion 13 by two connectors 15. The connectors 15 have filling channels 16 that communicate with the inner cavity of the inner semi-conductive tube 3 or the outer shielding cylinder 5.

[0030] In use, the inner sheath 7 and outer sheath 9 can be made of cold-shrink silicone rubber. The inner sheath 7 and outer sheath 9 are respectively fitted onto the two high-voltage cables using a pre-expansion liner for support. Then, the ends of the cores 17 of the two high-voltage cables are connected using a splice tube 1. Conductive adhesive is applied to the connection between the splice tube 1 and the core to reduce contact resistance. Then, the inner semi-conductive tube 3 is connected between the insulation layers 10 of the two high-voltage cables to wrap the splice tube 1 and the core. When connecting the inner semi-conductive tube 3, the connecting seam 12 on the inner semi-conductive tube 3 is connected and sealed using a connector 15. Then, the semi-conductive filler layer 2 is filled into the inner semi-conductive tube 3 using a filling channel 16. For example, the A agent epoxy resin + high-structure conductive carbon black and the B agent aromatic amine curing agent in the aromatic amine type medium-temperature curing epoxy semi-conductive adhesive are mixed and injected into one of the filling channels 16 by an injection gun. The other filling channel 16 is used to determine whether the filling is complete. The semi-conductive filling layer 2 tightly wraps the entire surface of the splice tube 1. The resistivity of the semi-conductive filling layer 2 is between that of the splice tube 1 and the insulation layer, which can form a smooth electric field transition layer and eliminate electric field concentration points. Then, the outer shielding cylinder 5 is connected between the main shielding layers 11 of the two high-voltage cables. When connecting the outer shielding cylinder 5, the connecting seam 12 on the outer shielding cylinder 5 is connected and sealed using the connector 15. Then, the filling material of the insulating filling layer 4, such as insulating resin, is filled into the outer shielding cylinder 5 using the filling channel 16. Subsequently, the two ends of the copper mesh 6 are fixedly connected to the copper shields 18 of the two high-voltage cables respectively. The inner sheath 7 is moved between the inner sheaths 19 of the two high-voltage cables and fixed by using the elastic recoil force to adhere to the copper mesh 6. After the armor tape 8 connecting the armor layers 20 of the two high-voltage cables is wrapped around the outside of the inner sheath 7, the outer sheath 9 is moved between the outer sheaths 21 of the high-voltage cables and fixed by using the elastic recoil force to adhere to the armor tape 8. Compared with the existing method of wrapping semi-conductive tape, the above connection process can avoid the problem of non-standard winding spacing or contamination of the semi-conductive tape. Furthermore, the inner semi-conductive tube 3 and the outer shielding cylinder 5 can be modularly produced and installed, which is beneficial to improving the connection efficiency of high-voltage cables.

[0031] In a further preferred embodiment, the connector 15 includes a threaded rod 151 and a sealing block 152 that are fixedly connected at the top and bottom. The top end of the threaded rod 151 is provided with a tightening nut 153. The boss 14 is provided with a threaded hole that is adapted to the structure of the threaded rod 151. The sealing block 152 covers the port of the threaded hole near the inner cavity. The flange 13 is provided with a through hole that is adapted to the structure of the threaded rod 151. The filling channel 16 passes through the connector 15 along the central axis direction of the connector 15.

[0032] In use, the sealing block 152, threaded rod 151, and nut work together to achieve a tight fit between the boss 14 and the flange 13. Simultaneously, the sealing block 152 seals the threaded hole, ensuring a seal between the connector 15 and the inner semi-conductive tube 3 or outer shielding cylinder 5. This allows the filler material of the semi-conductive filling layer 2 or the insulating filling layer 4 to enter and exit the inner cavity only through the filling channel 16. The cooperation between the threaded rod 151 and the threaded hole allows the connector 15 to be fixed on the boss 14 before connecting the flange 13 and the boss 14, thus facilitating the connection operation between the boss 14 and the flange 13.

[0033] In a further optimized design, the end of the threaded rod 151 furthest from the sealing block 152 is threadedly connected to a sealing cap 22.

[0034] When in use, the sealing cap 22 can seal the filling channel 16, effectively preventing the filling material in the semi-conductive filling layer 2 from being exposed or affected by the external environment.

[0035] A further optimized design includes an upper receiving groove on the curved outer wall of the semiconducting tube, corresponding to the sealing cap 22 and the tightening nut 153. This upper receiving groove accommodates the sealing cap 22 and the tightening nut 153, making the sealing cap 22 flush with the curved outer wall of the semiconducting tube. A lower receiving groove on the curved inner wall of the semiconducting tube, corresponding to the sealing block 152, also accommodates the sealing block 152, making it flush with the curved inner wall of the semiconducting tube. The top surface of the tightening nut 153 has a first slot 23, facilitating rotation by the installer. The top surface of the sealing cap 22 has a second slot 24, also facilitating rotation of the sealing cap 22.

[0036] During use, the upper and lower storage slots ensure a smooth surface on the semiconducting tube, preventing bulging and ensuring uniform electric field within the high-voltage cable joint.

[0037] In a further preferred embodiment, both ends of the inner wall of the inner semiconducting tube 3 are provided with grooves 25 coaxially arranged with the inner semiconducting tube 3. The end faces of the two grooves 25 are respectively in contact with the end planes of the insulation layers 10 of the two high-voltage cables, and the curved inner walls of the two grooves 25 are respectively in contact with the curved outer walls of the insulation layers 10 of the two high-voltage cables.

[0038] In use, the contact connection between the groove 25 and the end planes of the insulation layers 10 of the two high-voltage cables can fix the position of the inner semiconducting tube 3 and improve the stability of the inner semiconducting tube 3. The contact connection between the groove 25 and the curved outer wall of the insulation layers 10 of the two high-voltage cables can ensure that the inner semiconducting tube 3 can fully wrap around the connecting tube 1 and the core 17 of the high-voltage cable.

[0039] In a further optimized design, a high-elasticity inner shielding tube 26 is attached to the curved outer wall of the inner semiconducting tube 3, and a high-elasticity outer shielding tube 27 is attached to the outer shielding cylinder 5.

[0040] In use, the high-elasticity inner shielding tube 26 and the inner semiconducting tube 3 together form the inner shield of the high-voltage cable intermediate joint. The high-elasticity inner shielding tube 26 can further ensure the surface sealing of the inner semiconducting tube 3. The outer shielding cylinder 5 and the high-elasticity outer shielding tube 27 together form the outer shield of the high-voltage cable intermediate joint. The high-elasticity outer shielding tube 27 can improve the surface sealing of the outer shielding cylinder 5.

[0041] In a further optimized design, the two ends of the inner semiconducting tube 3 are connected to the insulation layer 10 of the two high-voltage cables by winding a constant force spring.

[0042] When in use, the constant force spring can increase the stability and sealing of the connection between the inner semiconducting tube 3 and the insulation layer 10 of the two high-voltage cables.

[0043] In a further preferred embodiment, a stress cone 28 is fixedly connected to the main shielding layer 11 of the high-voltage cable, and the peeling fracture between the main shielding layer 11 and the insulation layer 10 of the high-voltage cable is correspondingly located at the center of the connection port of the stress cone 28.

[0044] In use, before connecting the splice tube 1, the two stress cones 28 are fixed to the main shielding layers 11 of the two high-voltage cables respectively. The stress cones 28 can optimize the electric field distribution, eliminate electric field concentration, and avoid faults such as partial discharge and insulation breakdown caused by electric field distortion. In addition, after filling the insulating filler layer 4, the insulating filler layer 4 wraps around the stress cones 28, and the stress cones 28 improve the stability of the insulating filler layer 4.

[0045] In a further optimized scheme, the two ends of the splice tube 1 are respectively crimped to the ends of the cores 17 of the two high-voltage cables.

[0046] When in use, the crimped connection method can increase the stability between the splice tube 1 and the ends of the cores 17 of the two high-voltage cables.

[0047] Therefore, the high-voltage cable intermediate joint of the present invention with the above structure is beneficial to improving the connection quality of two high-voltage cables.

[0048] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0049] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A high-voltage cable intermediate joint, comprising, from the inside out, a splicing tube (1), a semi-conductive filling layer (2), an inner semi-conductive tube (3), an insulating filling layer (4), an outer shielding cylinder (5), a copper mesh (6), an inner sheath (7), an armor tape (8), and an outer sheath (9), characterized in that: The inner walls of the inner semiconducting tube (3) are respectively sealed to the insulation layers (10) of the two high-voltage cables at both ends, and the inner walls of the outer shielding cylinder (5) are respectively sealed to the main shielding layers (11) of the two high-voltage cables at both ends. The inner semiconducting tube (3) and the outer shielding cylinder (5) are provided with connecting seams (12). The connecting seams (12) include a first connecting surface and a second connecting surface. The first connecting surface is provided with a protruding edge (13) extending from the outer wall of the curved sidewall. The second connecting surface is provided with a boss (14) extending from the inner wall of the curved sidewall. The boss (14) is detachably connected to the protruding edge (13) through two connectors (15). The connectors (15) are provided with a filling channel (16) communicating with the inner cavity of the inner semiconducting tube (3) or the outer shielding cylinder (5). The connector (15) includes a threaded rod (151) and a sealing block (152) fixedly connected at the top and bottom. The top end of the threaded rod (151) is provided with a tightening nut (153). The boss (14) is provided with a threaded hole adapted to the structure of the threaded rod (151). The sealing block (152) covers the port of the threaded hole near the inner cavity. The flange (13) is provided with a through hole adapted to the structure of the threaded rod (151). The filling channel (16) passes through the connector (15) along the central axis direction.

2. The high-voltage cable intermediate joint according to claim 1, characterized in that: The threaded rod (151) is threaded to a sealing cap (22) at the end away from the sealing block (152).

3. The high-voltage cable intermediate joint according to claim 2, characterized in that: The curved outer wall of the semiconductive tube is provided with an upper storage groove corresponding to the sealing cap (22) and the tightening nut (153), the curved inner wall of the semiconductive tube is provided with a lower storage groove corresponding to the sealing block (152), the top surface of the tightening nut (153) is provided with a first slot (23), and the top surface of the sealing cap (22) is provided with a second slot (24).

4. The high-voltage cable intermediate joint according to claim 1, characterized in that: The inner wall of the inner semiconducting tube (3) is provided with grooves (25) coaxially arranged with the inner semiconducting tube (3) at both ends. The end faces of the two grooves (25) are respectively in contact with the end planes of the insulation layers (10) of the two high-voltage cables. The curved inner walls of the two grooves (25) are respectively in contact with the curved outer walls of the insulation layers (10) of the two high-voltage cables.

5. The high-voltage cable intermediate joint according to claim 1, characterized in that: A high-elasticity inner shielding tube (26) is attached to the curved outer wall of the inner semiconducting tube (3), and a high-elasticity outer shielding tube (27) is attached to the outer shielding tube (5).

6. The high-voltage cable intermediate joint according to claim 1, characterized in that: The two ends of the inner semiconducting tube (3) are connected to the insulation layer (10) of the two high-voltage cables by winding constant force springs.

7. The high-voltage cable intermediate joint according to claim 1, characterized in that: A stress cone (28) is fixedly connected to the main shielding layer (11) of the high-voltage cable. The peeling fracture between the main shielding layer (11) and the insulation layer (10) of the high-voltage cable is correspondingly set at the middle of the connection port of the stress cone (28).

8. The high-voltage cable intermediate joint according to claim 1, characterized in that: The two ends of the splice tube (1) are respectively crimped to the ends of the cores (17) of the two high-voltage cables.

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