Self-melting cable intermediate joint and use method thereof

Abstract

The invention discloses a self-fluxing cable intermediate joint and a use method thereof, and relates to the field of power transmission. The self-fusing cable intermediate joint comprises a joint unit, the joint unit is used for connecting cable units inserted at two ends of the joint unit, and the joint unit comprises an intermediate connecting section, interfaces arranged at two ends of the intermediate connecting section, and a conductor welding assembly embedded in the intermediate connecting section. According to the self-melting type cable intermediate joint, multiple strands of stranded core wires of two cables are inserted into the welding cavities of the joint units to be oppositely butted, and accurate positioning is completed through an extrusion structure of an interface; and then selecting a resistance synchronous heating or high-frequency induction heating mode to melt a molten conductor in the conductor welding assembly, enabling the molten conductor to uniformly flow into the welding cavity through the main flow guide groove and the branch micro-channels, filling a gap between the stranded core wires and the cavity wall, and cooling and curing to form physical and electrical dual connection.

Description

Technical Field

[0001] This invention relates to the field of power transmission, and particularly to a self-fusion cable joint and its usage method. Background Technology

[0002] Traditional cable joints have significant technical shortcomings:

[0003] In terms of connection performance, mechanical crimping joints rely on external pressure to fix the core wire. Over long-term use, vibration and thermal expansion and contraction can cause loosening of the contact, leading to increased conductivity, localized heating, and an inability to form a reliable physical and electrical connection. While fusion welding joints can fuse the core wire, uneven filling of the molten metal during field operations can easily create voids and slag inclusions, disrupting the continuity of electrical conduction. Furthermore, the physical connection strength is significantly affected by the welding process, resulting in insufficient stability. Both types of joints struggle to balance the robustness of the physical connection with the stability of electrical conduction, posing safety hazards for long-term line operation.

[0004] In terms of heating method adaptability, traditional joint heating methods are singular and highly limited: some joints only support high-frequency induction heating, requiring dedicated large equipment, and are not suitable for special construction scenarios such as confined spaces or no power supply; some joints rely on resistance heating, but most are single-point heating designs, which are prone to uneven heating, resulting in local overheating and damage to the molten conductor or incomplete melting, affecting the connection quality; the lack of heating solutions that can be flexibly switched according to the site environment leads to low construction efficiency and limited applicable scenarios. Summary of the Invention

[0005] The purpose of this invention is to provide a self-fusing cable intermediate joint and its usage method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a self-fusion cable intermediate joint, comprising a joint unit for connecting cable units inserted at both ends thereof, the joint unit comprising an intermediate connecting section, interfaces disposed at both ends of the intermediate connecting section, and a conductor fusion assembly embedded inside the intermediate connecting section;

[0007] The intermediate connecting section has a welding cavity that communicates with the interface. The cable unit consists of multiple stranded core wires and a sheath covering the outside of the multiple stranded core wires. First, the sheaths at the ends of the two cable units to be connected are stripped off, and the exposed multiple stranded core wires are inserted into the welding cavity and connected to each other. The cable unit is fixed in position through the interface.

[0008] The conductor welding assembly includes multiple insert slots, molten conductors inserted into the insert slots, and connecting conductors installed at both ends of the molten conductors. After the cable unit is positioned, the molten conductors are heated to melt them. The melted conductors flow into the welding cavity, fully contact the multi-strand stranded core wires, and fill the gap between the core wires and the inner wall of the welding cavity. Finally, the conductors are cooled and solidified to achieve both physical and electrical connections.

[0009] Preferably, the interface includes a retaining ring, a threaded sleeve mounted on the end face of the retaining ring, and a plurality of extrusion plates; the end face of the retaining ring is provided with a threaded groove, and the threaded sleeve is threadedly connected to the inner wall of the threaded groove;

[0010] Multiple extrusion plates are arranged in a circular array. An extrusion ring is fixedly connected to the inner wall of the fixing ring, and the extrusion ring is sleeved on the outside of the multiple extrusion plates. After the multi-strand stranded core wire is inserted into the welding cavity, the threaded sleeve is rotated to drive it to move axially along the threaded groove, thereby squeezing the multiple extrusion plates towards the center through the extrusion ring, and tightening and fixing the cable unit inserted into the interface.

[0011] Preferably, the conductor welding assembly further includes a main flow channel communicating with the welding cavity, and a plurality of branch microchannels densely distributed between the main flow channel and the embedding groove;

[0012] The molten conductor is first collected by branched microchannels into the main flow channel, and then evenly distributed to the welding cavity by the main flow channel.

[0013] Preferably, the insert groove is shaped as an inverted isosceles trapezoid, the main flow channel is shaped as a semicircle, and the branch microchannel is shaped as a circle to reduce the flow resistance of the molten conductor.

[0014] Preferably, the outer side of the interface is threaded with a sealing cap, and a sealing groove is formed on the inner wall of the sealing cap. The ends of the plurality of connecting conductors pass through the outer wall of the end of the intermediate connecting section and extend into the sealing groove.

[0015] Preferably, after the connector unit is connected to the cable units at both ends and the welding is completed, an insulating sealing unit is provided on the outside of the connector unit and the cable unit; the insulating sealing unit includes an outer silicone rubber sealing sleeve, an inner cross-linked polyethylene heat shrinkable insulating sleeve, and a water-swellable sealing strip disposed between the cross-linked polyethylene heat shrinkable insulating sleeve and the silicone rubber sealing sleeve.

[0016] First, the cross-linked polyethylene heat shrinkable insulation sleeve is wrapped around the outside of the cable unit, interface, sealing cover and intermediate connection section and fixed by heat shrinking. Then, a water-swellable sealing strip is laid on its outside. Finally, a silicone rubber sealing sleeve is wrapped around the outside of the joint unit, cable unit and cross-linked polyethylene heat shrinkable insulation sleeve to form a multi-layer sealing protection.

[0017] Preferably, the exposed ends of the plurality of connecting conductors can be connected to a resistance synchronous heating unit;

[0018] The resistance synchronous heating unit includes two symmetrically arranged semicircular sleeves. An insulating groove is opened inside the semicircular sleeve, and a semicircular conductive sheet is installed on the inner wall of the insulating groove. After the cable unit and the interface are tightened and fixed, the two semicircular sleeves are fitted together on the outside of the interface, so that the two semicircular conductive sheets are in close contact and conductively connected to the connecting conductor. Then, the sealing cover is tightened to squeeze and fix the two semicircular sleeves between the sealing cover and the middle connecting section.

[0019] Both of the two semicircular sleeves are equipped with contact plates on their outer sides, and the ends of the contact plates extend outward through the semicircular sleeves. Multiple molten conductors form a parallel circuit through connecting conductors and semicircular conductive plates. After fixing, the positive and negative poles of the constant current power supply are connected to the contact plates at both ends respectively. The parallel circuit enables synchronous electric heating of all molten conductors, so that the welding temperature is consistent.

[0020] Preferably, after the two semicircular sleeves are fitted onto the outside of the interface, their end faces can be inserted into the inner wall of the sealing cover. The outer sides of the two semicircular sleeves are respectively fixedly connected with a positioning block and a positioning rod. After the two semicircular sleeves are joined together, the positioning rod is inserted into the positioning block.

[0021] Preferably, the intermediate connecting section can be directly inserted into the high-frequency induction coil;

[0022] After the cable unit and interface are tightened and fixed, the intermediate connecting section is inserted into the high-frequency induction coil. The high-frequency induction coil causes the intermediate connecting section to heat up through an alternating magnetic field. The heat is evenly transferred along the axial direction to the molten conductor in the mounting groove, causing it to slowly melt and flow into the welding cavity.

[0023] The method of using a self-fusion cable joint includes the following steps:

[0024] S1: Cable pretreatment, strip the sheaths from the ends of the two cable units to be connected to expose the multi-strand stranded core wires of the preset length, and thoroughly clean the oxide layer and impurities on the surface of the multi-strand stranded core wires;

[0025] S2: Connector assembly and positioning. Insert the multi-strand stranded core wires of the two cable units into the welding cavities at both ends of the intermediate connection section, so that the two sets of multi-strand stranded core wires are aligned and connected to the preset position. Use the interface to tighten the cable unit to complete the positioning.

[0026] S3: Select the heating method and perform welding. Method 1: Connect the two semi-circular sleeves on the outside of the interface, accurately position them using the positioning block and positioning rod, tighten the sealing cover to fix the synchronous heating unit, connect the positive and negative terminals of the constant current power supply to the two terminals, after powering on, the molten conductor melts and fills the gap, after heating is completed, turn off the power, and when the molten conductor has initially cooled to a non-flowing state, unscrew the sealing cover, take out the two connected semi-circular sleeves, and complete the disassembly of the synchronous heating unit; Method 2: Insert the middle connecting section into the high-frequency induction coil, start the coil to make the middle connecting section heat up, drive the molten conductor to melt and fill the gap, after completion, take out the induction coil and let it cool naturally;

[0027] S4: Multi-layer insulation seal. After the molten conductor has completely cooled and solidified, first wrap the joint and cable connection with a cross-linked polyethylene heat shrink insulation sleeve and heat shrink it, then lay a water-swellable water-stop strip, and finally put on a silicone rubber sealing sleeve and compact it to complete the overall connection and protection.

[0028] The technical effects and advantages of this invention are as follows:

[0029] 1. Reliable cable splicing is achieved through a three-step core process of positioning, welding, and sealing, as follows: First, the cable unit is pre-treated by stripping the end sheaths and cleaning the multi-strand stranded core wires; then, the multi-strand stranded core wires of the two cables are inserted into the welding cavity of the joint unit and aligned face to face, achieving precise positioning through the extrusion structure of the interface; next, resistance synchronous heating or high-frequency induction heating is selected to melt the molten conductor in the conductor welding assembly. The molten conductor flows evenly into the welding cavity through the main flow channel and branch microchannels, filling the gap between the multi-strand stranded core wires and the cavity wall. After cooling and solidification, a dual physical and electrical connection is formed; finally, the multi-layer structure of the insulation sealing unit achieves insulation, waterproofing, and corrosion protection at the joint and cable connection point, ensuring long-term stable operation of the line.

[0030] 2. The resistance synchronous heating unit is installed by connecting two semi-circular sleeves, which is convenient and allows for quick and easy conductive connection with the connecting conductor. The semi-circular conductive plate makes tight contact with the connecting conductor, ensuring stable conductivity. Multiple molten conductors form a parallel circuit through the connecting conductor and the semi-circular conductive plate. After applying a constant current power supply, synchronous heating can be achieved, ensuring that the temperature of each molten conductor is consistent and avoiding damage to components due to local overheating or connection failure due to local incomplete melting. The sealing cover can press and fix the semi-circular sleeves, ensuring reliable conductive contact during heating. The resistance synchronous heating unit can be reused after disassembly, reducing construction costs. The heating method is flexible and suitable for scenarios where there is no high-frequency induction equipment on site.

[0031] 3. The high-frequency induction coil causes the intermediate connecting section to be heated as a whole. The heat is evenly transferred along the axial direction to the molten conductor, avoiding local overheating and ensuring that the molten conductor melts slowly and evenly, improving the filling quality and connection reliability. During the heating process, the intermediate connecting section is heated as a whole, which can preheat the multi-stranded core wire in the welding cavity, facilitating better wetting and bonding between the molten conductor and the core wire, further improving the mechanical strength and conductivity of the joint. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 This is a schematic diagram of the connector unit of the present invention;

[0034] Figure 3 This is a schematic diagram of the cable unit structure of the present invention;

[0035] Figure 4 This is an exploded view of the interface structure of the present invention;

[0036] Figure 5 This is a partial structural cross-sectional view of the connector unit of the present invention;

[0037] Figure 6 This is a planar sectional view of the present invention;

[0038] Figure 7 This is a schematic diagram of the structure of the present invention after the insulation and sealing unit is installed;

[0039] Figure 8 This is an exploded view of the insulating sealing unit of the present invention;

[0040] Figure 9 This is a schematic diagram of the structure of the present invention after the installation of the resistance synchronous heating unit;

[0041] Figure 10 This is a cross-sectional view of the connection between the connector unit and the resistance synchronous heating unit of the present invention;

[0042] Figure 11 This is a schematic diagram of the structure of the resistance synchronous heating unit of the present invention.

[0043] In the diagram: 1. Connector unit; 11. Intermediate connecting section; 111. Welding cavity; 12. Interface; 121. Fixing ring; 122. Threaded groove; 123. Threaded sleeve; 124. Extrusion plate; 125. Extrusion ring; 13. Conductor welding assembly; 131. Embedding groove; 132. Main flow groove; 133. Branch microchannel; 134. Molten conductor; 135. Connecting conductor; 14. Sealing cap; 141. Sealing groove; 2. Cable unit; 21. Sheath; 22. Multi-strand stranded core wire; 3. Insulation sealing unit; 31. Silicone rubber sealing sleeve; 32. Cross-linked polyethylene heat shrink insulation sleeve; 33. Water-swellable sealing strip; 4. Resistance synchronous heating unit; 41. Semicircular sleeve; 42. Insulation groove; 43. Semicircular conductive plate; 44. Connecting plate; 45. Positioning block; 46. Positioning rod. Detailed Implementation

[0044] 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.

[0045] This invention provides, for example Figures 1-11 The diagram shows a connector unit 1 for connecting cable units 2 plugged into its two ends. The connector unit 1 includes an intermediate connecting section 11, interfaces 12 disposed at both ends of the intermediate connecting section 11, and a conductor welding assembly 13 embedded inside the intermediate connecting section 11.

[0046] The intermediate connecting section 11 has a welding cavity 111 that communicates with the interface 12. The cable unit 2 is composed of multi-strand stranded core wires 22 and a sheath 21 covering the outside of the multi-strand stranded core wires 22. First, the sheaths 21 at the ends of the two cable units 2 to be connected are stripped, and the exposed multi-strand stranded core wires 22 are inserted into the welding cavity 111 and connected to each other. The position of the cable unit 2 is fixed through the interface 12.

[0047] The conductor welding assembly 13 includes multiple insert grooves 131, a molten conductor 134 inserted in the insert grooves 131, and connecting conductors 135 installed at both ends of the molten conductor 134. After the cable unit 2 is positioned, the molten conductor 134 is heated to melt it. The molten conductor 134 flows into the welding cavity 111, fully contacts the multi-strand stranded core wire 22 and fills the gap between it and the inner wall of the welding cavity 111. Finally, it cools and solidifies to achieve a dual physical and electrical connection.

[0048] Reliable cable splicing is achieved through a three-step core process of positioning, welding, and sealing, as follows: First, cable unit 2 is pre-treated by stripping the end sheath 21 and cleaning the multi-strand stranded core wires 22; then, the multi-strand stranded core wires 22 of the two cables are inserted into the welding cavity 111 of the joint unit 1 and aligned, with precise positioning achieved through the extrusion structure of the interface 12; next, resistance synchronous heating or high-frequency induction heating is selected to melt the molten conductor 134 in the conductor welding assembly 13. The molten conductor 134 flows evenly into the welding cavity 111 through the main flow channel 132 and the branch microchannel 133, filling the gap between the multi-strand stranded core wires 22 and the cavity wall. After cooling and solidification, a dual physical and electrical connection is formed; finally, the multi-layer structure of the insulation sealing unit 3 achieves insulation, waterproofing, and corrosion protection at the joint and cable connection point, ensuring long-term stable operation of the line.

[0049] Furthermore, the interface 12 includes a retaining ring 121, a threaded sleeve 123 mounted on the end face of the retaining ring 121, and a plurality of extrusion plates 124; the end face of the retaining ring 121 is provided with a threaded groove 122, and the threaded sleeve 123 is threadedly connected to the inner wall of the threaded groove 122.

[0050] Multiple extrusion plates 124 are arranged in a circular array. An extrusion ring 125 is fixedly connected to the inner wall of the fixing ring 121, and the extrusion ring 125 is sleeved on the outside of the multiple extrusion plates 124. After the multi-strand stranded core wire 22 is inserted into the welding cavity 111, the threaded sleeve 123 is rotated to drive it to move axially along the threaded groove 122, thereby squeezing the multiple extrusion plates 124 towards the center through the extrusion ring 125, and tightening and fixing the cable unit 2 inserted into the interface 12.

[0051] The retaining ring 121, threaded sleeve 123, and extrusion plate 124 of interface 12 constitute an adjustable tightening structure. The extrusion ring 125, driven by the thread, compresses the extrusion plate 124, allowing for the adaptation to cable units 2 of different diameters and providing strong versatility. The threaded connection allows for precise adjustment and uniform tightening force, firmly fixing the cable unit 2 within interface 12 and preventing displacement of the multi-stranded core wires 22 within the welding cavity 111 during fusion, ensuring welding accuracy and quality. The extrusion plates 124 are arranged in a circular array, providing uniform contact area with the cable sheath 21 during tightening, preventing excessive local pressure from damaging the sheath 21 and improving stability.

[0052] Furthermore, the conductor welding assembly 13 also includes a main flow channel 132 connected to the welding cavity 111, and a plurality of branch microchannels 133 densely distributed between the main flow channel 132 and the insert groove 131.

[0053] The molten conductor 134 is first collected by the branch microchannel 133 into the main flow channel 132, and then evenly distributed by the main flow channel 132 to the welding cavity 111.

[0054] The main flow channel 132 and the branch microchannels 133 form a flow guiding network, allowing the molten conductor 134 to first converge and then be evenly distributed to the welding cavity 111, avoiding localized insufficient filling or accumulation and ensuring sufficient contact between the core wire and the molten conductor 134. The flow guiding structure reduces the flow resistance of the molten conductor 134, accelerates the filling speed, and improves welding efficiency, while avoiding defects such as bubbles and voids caused by poor flow, ensuring continuity of conductivity. Multiple branch microchannels 133 correspond to the embedding groove 131, allowing each molten conductor 134 to flow into the main flow channel 132 through an independent channel, achieving multi-source synchronous filling and further improving filling uniformity.

[0055] Furthermore, the insert groove 131 is designed as an inverted isosceles trapezoid, the main flow channel 132 is designed as a semicircle, and the branch microchannel 133 is designed as a circle to reduce the flow resistance of the molten conductor 134.

[0056] The insert groove 131 is designed as an inverted isosceles trapezoid to increase the heating area and flow outlet of the molten conductor 134, facilitating rapid melting and flow into the branch microchannel 133. The main flow groove 132 is designed as a semi-circle to reduce the wall resistance during the flow of the molten conductor 134 and accelerate the confluence speed; the branch microchannel 133 is designed as a circle to further reduce flow resistance and prevent the molten conductor 134 from stagnating in the channel. The specific shape design works synergistically to make the molten conductor 134 flow more smoothly and fill more efficiently, effectively reducing welding defects and improving the conductivity and mechanical strength of the joint.

[0057] Furthermore, a sealing cap 14 is threaded onto the outer side of the interface 12. A sealing groove 141 is provided on the inner wall of the sealing cap 14. The ends of multiple connecting conductors 135 pass through the outer wall of the end of the intermediate connecting section 11 and extend into the sealing groove 141.

[0058] The sealing cap 14 is threadedly connected to the interface 12, which can seal and protect the inside of the interface 12, preventing impurities and moisture from entering the welding cavity 111 before welding, ensuring a clean welding environment and improving welding quality. The end of the connecting conductor 135 extends into the sealing groove 141 of the sealing cap 14. The sealing groove 141 can protect the end of the connecting conductor 135 from oxidation or damage, and at the same time provide a precise docking and installation reference for the resistance synchronous heating unit 4.

[0059] Furthermore, after the connector unit 1 is connected to the cable units 2 at both ends and the welding is completed, an insulating sealing unit 3 is provided on the outside of the connector unit 1 and the cable unit 2; the insulating sealing unit 3 includes an outer silicone rubber sealing sleeve 31, an inner cross-linked polyethylene heat shrink insulation sleeve 32, and a water-swellable sealing strip 33 disposed between the cross-linked polyethylene heat shrink insulation sleeve 32 and the silicone rubber sealing sleeve 31.

[0060] First, the cross-linked polyethylene heat shrinkable insulation sleeve 32 is wrapped around the outside of the connection of the cable unit 2, the interface 12, the sealing cover 14 and the intermediate connection section 11 and fixed by heat shrinking. Then, a water-swellable sealing strip 33 is laid on its outside. Finally, a silicone rubber sealing sleeve 31 is wrapped around the outside of the joint unit 1, the cable unit 2 and the cross-linked polyethylene heat shrinkable insulation sleeve 32 to form a multi-layer sealing protection.

[0061] The insulating sealing unit 3 employs a multi-layered structure consisting of a silicone rubber sealing sleeve 31, a cross-linked polyethylene heat-shrinkable insulating sleeve 32, and a water-swellable sealing strip 33, achieving triple protection of insulation, waterproofing, and protection, making it suitable for harsh environments such as dampness and corrosion. The cross-linked polyethylene heat-shrinkable insulating sleeve 32, after heating, tightly wraps around the joint and cable connection, providing excellent insulation performance and a good fit. The water-swellable sealing strip 33 automatically expands upon contact with water, filling tiny gaps and improving waterproof reliability. The silicone rubber sealing sleeve 31 provides outer protection, is wear-resistant and anti-aging, extending the joint's service life. The multi-layered sealing structure has a simple installation process, requiring no complex tools, allowing for rapid completion of overall protection, improving construction efficiency, and ensuring the integrity and stability of the seal.

[0062] Furthermore, the ends of the multiple connecting conductors 135 exposed to the outside can be connected to the resistance synchronous heating unit 4;

[0063] The resistance synchronous heating unit 4 includes two symmetrically arranged semi-circular sleeves 41. The semi-circular sleeves 41 have an insulating groove 42 inside, and a semi-circular conductive sheet 43 is installed on the inner wall of the insulating groove 42. After the cable unit 2 and the interface 12 are tightened and fixed, the two semi-circular sleeves 41 are fitted together on the outside of the interface 12, so that the two semi-circular conductive sheets 43 are in close contact and electrically connected to the connecting conductor 135. Then, the sealing cover 14 is tightened to squeeze and fix the two semi-circular sleeves 41 between the sealing cover 14 and the intermediate connecting section 11.

[0064] Two semicircular sleeves 41 are each equipped with a contact plate 44 on their outer sides. The ends of the contact plates 44 extend outward through the semicircular sleeves 41. Multiple molten conductors 134 form a parallel circuit through connecting conductors 135 and semicircular conductive plates 43. After fixing, the positive and negative poles of the constant current power supply are connected to the two contact plates 44 respectively. The parallel circuit enables synchronous electric heating of all molten conductors 134, so that the welding temperature is consistent.

[0065] The resistance synchronous heating unit 4 is installed by connecting two semi-circular sleeves 41, which is convenient to operate and can quickly achieve conductive connection with the connecting conductor 135. The semi-circular conductive plate 43 is in tight contact with the connecting conductor 135, ensuring stable conductivity. Multiple molten conductors 134 form a parallel circuit through the connecting conductor 135 and the semi-circular conductive plate 43. After applying a constant current power supply, synchronous heating can be achieved, ensuring that the temperature of each molten conductor 134 is consistent and avoiding local overheating damage to components or connection failure due to local incomplete melting. The sealing cover 14 can press and fix the semi-circular sleeves 41 to ensure reliable conductive contact during heating. The resistance synchronous heating unit 4 can be reused after disassembly, reducing construction costs. The heating method is flexible and suitable for scenarios where there is no high-frequency induction equipment on site.

[0066] Furthermore, after the two semicircular sleeves 41 are fitted onto the outside of the interface 12, their end faces can be inserted into the inner wall of the sealing cover 14. The outer sides of the two semicircular sleeves 41 are respectively fixedly connected with positioning blocks 45 and positioning rods 46. After the two semicircular sleeves 41 are joined together, the positioning rods 46 are inserted into the positioning blocks 45.

[0067] The end face of the semicircular sleeve 41 is inserted into the inner wall of the sealing cover 14. Combined with the insertion and positioning of the positioning block 45 and the positioning rod 46, precise alignment of the semicircular sleeve 41 is achieved, ensuring reliable contact between the semicircular conductive sheet 43 and the connecting conductor 135, preventing uneven heating due to poor contact during heating. The positioning structure design makes the installation and disassembly of the semicircular sleeve 41 more convenient, requiring no additional fixing tools and improving construction efficiency. The aligned semicircular sleeve 41 has a stable structure and will not shift during heating, ensuring consistent heating performance.

[0068] Furthermore, the intermediate connecting section 11 can be directly inserted into the high-frequency induction coil;

[0069] After the cable unit 2 and the interface 12 are tightened and fixed, the intermediate connecting section 11 is inserted into the high-frequency induction coil. The high-frequency induction coil causes the intermediate connecting section 11 to be heated by the alternating magnetic field. The heat is evenly transferred along the axial direction to the molten conductor 134 in the mounting groove 131, so that it slowly melts and flows into the welding cavity 111.

[0070] The high-frequency induction coil causes the intermediate connecting section 11 to be heated as a whole. The heat is evenly transferred along the axial direction to the molten conductor 134, avoiding local overheating and ensuring that the molten conductor 134 melts slowly and evenly, thus improving the filling quality and connection reliability. During the heating process, the intermediate connecting section 11 is heated as a whole, which can preheat the multi-strand stranded core wire 22 in the welding cavity 111, facilitating better wetting and bonding between the molten conductor 134 and the core wire, further improving the mechanical strength and conductivity of the joint.

[0071] The method for using a self-fusion cable joint includes the following steps:

[0072] S1: Cable pretreatment, strip the sheaths 21 from the ends of the two cable units 2 to be connected, exposing the multi-strand stranded core wires 22 of a preset length, and thoroughly clean the oxide layer and impurities on the surface of the multi-strand stranded core wires 22.

[0073] S2: Connector assembly and positioning. Insert the multi-strand stranded core wires 22 of the two cable units 2 into the welding cavities 111 at both ends of the intermediate connecting section 11, so that the two sets of multi-strand stranded core wires 22 are aligned and connected to the preset position. Use the interface 12 to tighten the cable unit 2 to complete the positioning.

[0074] S3: Select the heating method and perform welding. Method 1: Connect two semi-circular sleeves 41 to the outside of the interface 12. Precisely position them using the positioning block 45 and positioning rod 46. Tighten the sealing cover 14 to fix the resistance synchronous heating unit 4. Connect the positive and negative terminals of the constant current power supply to the two terminals 44. After powering on, the molten conductor 134 melts and fills the gap. After heating is complete, turn off the power. When the molten conductor 134 has cooled to a non-flowing state, unscrew the sealing cover 14 and remove the two connected semi-circular sleeves 41 to complete the disassembly of the resistance synchronous heating unit 4. Method 2: Insert the intermediate connecting section 11 into the high-frequency induction coil. Start the coil to make the intermediate connecting section 11 heat up, which drives the molten conductor 134 to melt and fill the gap. After completion, remove the induction coil and let it cool naturally.

[0075] S4: Multi-layer insulation seal. After the molten conductor 134 has completely cooled and solidified, first wrap the joint with the cable connection with the cross-linked polyethylene heat shrink insulation sleeve 32 and heat shrink it, then lay the water-swellable water-stop strip 33, and finally put on the silicone rubber sealing sleeve 31 and compact it to complete the overall connection and protection.

[0076] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-fusion type cable joint, comprising a joint unit (1) for connecting cable units (2) inserted at its two ends, characterized in that, The connector unit (1) includes an intermediate connecting section (11), interfaces (12) disposed at both ends of the intermediate connecting section (11), and a conductor welding assembly (13) embedded inside the intermediate connecting section (11). The intermediate connecting section (11) has a welding cavity (111) that communicates with the interface (12). The cable unit (2) is composed of multi-strand stranded core wires (22) and a sheath (21) covering the outside of the multi-strand stranded core wires (22). First, strip the sheaths (21) from the ends of the two cable units (2) to be connected, insert the exposed multi-strand stranded core wires (22) into the welding cavity (111) and connect them to each other. Fix the position of the cable unit (2) through the interface (12). The conductor welding assembly (13) includes multiple insert slots (131), a molten conductor (134) inserted in the insert slots (131), and connecting conductors (135) installed at both ends of the molten conductor (134). After the cable unit (2) is positioned, the molten conductor (134) is heated to melt it. The melted molten conductor (134) flows into the welding cavity (111), fully contacts the multi-strand stranded core wire (22), and fills the gap between it and the inner wall of the welding cavity (111). Finally, it cools and solidifies to achieve a dual physical and electrical connection.

2. The self-fusion cable joint according to claim 1, characterized in that, The interface (12) includes a retaining ring (121), a threaded sleeve (123) installed on the end face of the retaining ring (121), and a plurality of extrusion plates (124); the end face of the retaining ring (121) is provided with a threaded groove (122), and the threaded sleeve (123) is threadedly connected to the inner wall of the threaded groove (122); Multiple extrusion plates (124) are arranged in a circular array. An extrusion ring (125) is fixedly connected to the inner wall of the fixing ring (121), and the extrusion ring (125) is sleeved on the outside of the multiple extrusion plates (124). After the multi-strand stranded core wire (22) is inserted into the welding cavity (111), the threaded sleeve (123) is rotated to drive it to move axially along the threaded groove (122), and then the multiple extrusion plates (124) are squeezed to shrink towards the center by the extrusion ring (125) to tighten and fix the cable unit (2) inserted into the interface (12).

3. The self-fusion cable joint according to claim 1, characterized in that, The conductor welding assembly (13) also includes a main flow channel (132) connected to the welding cavity (111) and a plurality of branch microchannels (133) densely distributed between the main flow channel (132) and the insert groove (131). The molten conductor (134) after melting first flows through the branch microchannel (133) to the main flow channel (132), and then flows evenly from the main flow channel (132) to the welding cavity (111).

4. The self-fusion cable joint according to claim 3, characterized in that, The embedding groove (131) is designed as an inverted isosceles trapezoid, the main flow channel (132) is designed as a semicircle, and the branch microchannel (133) is designed as a circle to reduce the flow resistance of the molten conductor (134).

5. The self-fusion cable joint according to claim 1, characterized in that, The outer side of the interface (12) is threaded with a sealing cap (14), and a sealing groove (141) is provided on the inner wall of the sealing cap (14). The ends of the multiple connecting conductors (135) pass through the outer wall of the end of the intermediate connecting section (11) and extend into the sealing groove (141).

6. The self-fusion cable joint according to claim 5, characterized in that, After the connector unit (1) is connected to the cable units (2) at both ends and the welding is completed, an insulating sealing unit (3) is provided on the outside of the connector unit (1) and the cable unit (2); the insulating sealing unit (3) includes an outer silicone rubber sealing sleeve (31), an inner cross-linked polyethylene heat shrink insulation sleeve (32), and a water-swellable sealing strip (33) set between the cross-linked polyethylene heat shrink insulation sleeve (32) and the silicone rubber sealing sleeve (31). First, the cross-linked polyethylene heat shrinkable insulation sleeve (32) is wrapped around the outside of the connection of the cable unit (2), the interface (12), the sealing cover (14) and the intermediate connection section (11) and heated and shrunk to fix it. Then, a water-swellable sealing strip (33) is laid on its outside. Finally, a silicone rubber sealing sleeve (31) is wrapped around the outside of the joint unit (1), the cable unit (2) and the cross-linked polyethylene heat shrinkable insulation sleeve (32) to form a multi-layer sealing protection.

7. The self-fusion cable joint according to claim 5, characterized in that, The exposed ends of the multiple connecting conductors (135) can be connected to a resistance synchronous heating unit (4). The resistance synchronous heating unit (4) includes two symmetrically arranged semi-circular sleeves (41). An insulating groove (42) is opened inside the semi-circular sleeve (41), and a semi-circular conductive sheet (43) is installed on the inner wall of the insulating groove (42). After the cable unit (2) and the interface (12) are tightened and fixed, the two semi-circular sleeves (41) are fitted together on the outside of the interface (12) so that the two semi-circular conductive sheets (43) are in close contact and electrically connected to the connecting conductor (135). Then, the sealing cover (14) is tightened to squeeze and fix the two semi-circular sleeves (41) between the sealing cover (14) and the intermediate connecting section (11). Both of the two semicircular sleeves (41) are equipped with contact plates (44) on their outer sides. The ends of the contact plates (44) extend outward through the semicircular sleeves (41). Multiple molten conductors (134) form a parallel circuit through connecting conductors (135) and semicircular conductive plates (43). After fixing, the positive and negative poles of the constant current power supply are connected to the contact plates (44) at both ends respectively. The parallel circuit enables synchronous electric heating of all molten conductors (134) so ​​that the welding temperature is consistent.

8. The self-fusion cable joint according to claim 7, characterized in that, After the two semicircular sleeves (41) are fitted onto the outside of the interface (12), their end faces can be inserted into the inner wall of the sealing cover (14). The outer sides of the two semicircular sleeves (41) are respectively fixedly connected with a positioning block (45) and a positioning rod (46). After the two semicircular sleeves (41) are joined together, the positioning rod (46) is inserted into the positioning block (45).

9. The self-fusion cable joint according to claim 1, characterized in that, The intermediate connecting section (11) can be directly inserted into the high-frequency induction coil; After the cable unit (2) and the interface (12) are tightened and fixed, the intermediate connecting section (11) is inserted into the high-frequency induction coil. The high-frequency induction coil causes the intermediate connecting section (11) to be heated by the alternating magnetic field. The heat is evenly transferred along the axial direction to the molten conductor (134) in the mounting groove (131), so that it slowly melts and flows into the welding cavity (111).

10. A method for using a self-fusion cable joint, employing the self-fusion cable joint as described in any one of claims 1-9, characterized in that, The method of use includes the following steps: S1: Cable pretreatment, strip the sheaths (21) at the ends of the two cable units (2) to be connected, expose the multi-strand stranded core wires (22) of the preset length, and thoroughly clean the oxide layer and impurities on the surface of the multi-strand stranded core wires (22); S2: Connector assembly and positioning. Insert the multi-strand stranded core wires (22) of the two cable units (2) into the welding cavities (111) at both ends of the intermediate connecting section (11) respectively, so that the two sets of multi-strand stranded core wires (22) are connected to the preset position. Use the interface (12) to tighten the cable unit (2) to complete the positioning. S3: Select the heating method and perform welding. Method 1: Connect two semi-circular sleeves (41) on the outside of the interface (12), accurately position them by positioning block (45) and positioning rod (46), tighten the sealing cover (14) to fix the resistance synchronous heating unit (4), connect the positive and negative poles of the constant current power supply to the two terminals (44), after powering on, the molten conductor (134) melts and fills the gap, after heating is completed, turn off the power, and when the molten conductor (134) has cooled to a state of no flow, unscrew the sealing cover (14), take out the two connected semi-circular sleeves (41), and complete the disassembly of the resistance synchronous heating unit (4); Method 2: Insert the middle connecting section (11) into the high-frequency induction coil, start the coil to make the middle connecting section (11) heat up, drive the molten conductor (134) to melt and fill the gap, after completion, take out the induction coil and let it cool naturally. S4: Multi-layer insulation seal. After the molten conductor (134) has completely cooled and solidified, first wrap the joint with the cable connection with a cross-linked polyethylene heat shrink insulation sleeve (32) and heat it to shrink. Then lay the water-swellable sealing strip (33). Finally, put on the silicone rubber sealing sleeve (31) and compact it to complete the overall connection and protection.

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