Corrosion-resistant tensile cross-linked polyethylene aerial cable

Abstract

The invention relates to the technical field of cables, and discloses a corrosion-resistant tensile crosslinked polyethylene aerial cable. Comprising a plurality of cable cores and a power-off mechanism, and the periphery of each cable core is coated with an insulating layer; and a power-off mechanism is arranged at the disconnected part of each cable core, and when the cable cores are subjected to axial tension exceeding a preset threshold value, the power-off mechanisms are triggered and automatically disconnect the electrical connection of the cable cores. The power-off mechanism is arranged at the disconnection position of each cable core, and when the cable cores are subjected to axial tension exceeding the preset threshold value, electrical connection can be actively and timely disconnected, so that secondary electrical faults such as short circuit and arc discharge caused by cable core breakage are avoided, and the safety and reliability of the cable under the dynamic stress working condition are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and specifically to a corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable. Background Technology

[0002] Cross-linked polyethylene (XLPE) insulated control cables are widely used in power transmission and control systems in power plants, industrial and mining enterprises, and other applications due to their excellent electrical properties, heat resistance, and mechanical strength. In complex electromagnetic environments in industrial settings, shielding layers or specific stranded structures are often used to ensure interference resistance. However, during laying, installation, and long-term operation, cables may be subjected to radial pressure and axial tension, especially under dynamic or complex conditions. If external mechanical stress (such as excessive traction or equipment displacement) causes the axial tension on the cable core to exceed its strength limit, the conductor may break or suffer latent damage. For example, patent CN207149309U discloses a "freezing-resistant and interference-resistant cross-linked polyethylene insulated frequency conversion power cable," which improves shielding and environmental adaptability, but does not address active intervention mechanisms for electrical connections under dynamic mechanical overload. This cable passively withstands abnormal tension until physical breakage, and the electrical risks at the moment of breakage and subsequent events are not considered in the design. Summary of the Invention

[0003] The main objective of this invention is to provide a corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable to solve the problem in the prior art where cables passively bear abnormal tensile forces until they physically break.

[0004] To achieve the above objectives, the present invention provides a corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable, comprising multiple cable cores, each cable core being covered with an insulation layer, and also including a power-off mechanism. Each cable core is equipped with a power-off mechanism at the break point. When the cable core is subjected to an axial tensile force exceeding a preset threshold, the power-off mechanism is triggered and automatically disconnects the electrical connection of the cable core.

[0005] Preferably, the power-off mechanism includes an inner tube and an outer tube; One end of the inner tube and one end of the outer tube are each connected to a connecting pipe, and the two connecting pipes are respectively fixedly connected to two sections of cable core; An annular boss is coaxially provided on the outer wall of the inner tube; The outer tube is coaxially sleeved on the outside of the inner tube, and the annular boss is located between the inner tube and the outer tube; An annular groove is formed on the outer wall of the inner tube along its circumference, and a limiting ring is slidably disposed in the annular groove along its axial direction. The outer wall of the annular boss is provided with multiple receiving grooves along its circumference. A spring is installed in each receiving groove. One end of the spring is connected to the bottom wall of the receiving groove, and the other end is connected to a sphere. A portion of the sphere extends out of the receiving groove and abuts against the inner wall of the outer tube and the side wall of the receiving groove; A disconnecting annular groove is formed on the inner wall of the outer tube; When the cable core is subjected to axial tension, the inner tube and the outer tube undergo relative axial displacement, driving the ball to embed into the disconnection groove to block the current path.

[0006] Preferably, the outer ring wall of the limiting ring is provided with an annular blind groove, and the ring wall of the limiting ring is provided with at least one opening along the axial direction, the opening communicating with the annular blind groove; The power-off mechanism also includes a locking sleeve, which is coaxially disposed inside the outer tube, and one end of the locking sleeve is coaxially connected to the limit ring. At least one operating window is provided on the wall of the outer tube. A frame is fixedly installed at the operating window. A rotating shaft is installed on the frame. A locking arm that can rotate around the rotating shaft is fitted on the rotating shaft. One end of the locking arm extends into the operating window and is fixedly connected to an arc-shaped block and an insert block. The insert block passes through the opening and extends into the annular blind groove, while the arc-shaped block is located in the annular groove. When the limiting ring rotates to the predetermined position, the insert block and the opening are misaligned in the circumferential direction, so that the limiting ring and the locking sleeve are locked between the inner tube and the outer tube.

[0007] Preferably, the corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable further includes a first electrical tape, which is wrapped around the outer periphery of the power-off mechanism and the adjacent insulation layer.

[0008] Preferably, the corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable further includes, from the inside out, a filling layer, a shielding layer, a fire-resistant wrapping layer, and an outer sheath, which are sequentially wrapped around the outside of the insulation layer.

[0009] Preferably, a pressure sensor is installed inside the disconnected annular groove; When the cable core is subjected to axial tension, the inner tube and the outer tube undergo relative axial displacement, driving the ball to embed into the disconnection ring groove and contact the pressure sensor; The pressure sensor is connected to a monitoring unit, which sends a command to block the current path based on the pressure signal.

[0010] Preferably, the power-off mechanism further includes two support rings, a screw, multiple fastening nuts, and a second electrical tape; Each support ring has multiple support grooves along the circumference, and multiple cable cores correspond one-to-one with multiple support grooves and are embedded in the support grooves; The screw passes through two support rings, and each support ring has a fastening nut on both sides, which is threadedly connected to the screw. The second electrical tape is wrapped around the outer periphery of the first electrical tape and the adjacent outer sheath, so that a heat dissipation cavity is formed between the two support rings.

[0011] The beneficial effects of the above scheme are: By installing a power-off mechanism at the break point of each cable core, the electrical connection can be actively and promptly disconnected when the cable core is subjected to axial tensile force exceeding a preset threshold. This avoids secondary electrical faults such as short circuits and arcing caused by cable core breakage, significantly improving the safety and reliability of the cable under dynamic stress conditions. Traditional cables passively withstand overload tension until physical breakage, which can easily lead to dangers such as electric arcs and partial short circuits. This solution, through the pre-action of the power-off mechanism, cuts off the circuit before the cable core physically breaks, fundamentally eliminating the electrical safety hazards caused by breakage. It is particularly suitable for power plants, mines, and other applications with strict safety requirements. Attached Figure Description

[0012] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0013] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 yes Figure 1 A three-dimensional structural diagram of the structure after removing the second electrical tape; Figure 3 This is a partial three-dimensional structural schematic diagram of the present invention; Figure 4 This is a partial three-dimensional structural schematic diagram of the present invention; Figure 5 yes Figure 3 A structural schematic diagram in cross-sectional view; Figure 6 yes Figure 5 Enlarged structural diagram of region A in the middle; Figure 7 yes Figure 5 A magnified structural diagram of region B in the middle; Figure 8 This is a partial three-dimensional structural schematic diagram of the present invention.

[0014] Explanation of reference numerals in the attached figures 1. Cable core; 2. Insulation layer; 3. Power-off mechanism; 31. Connecting pipe; 311. Annular boss; 312. Receiving groove; 313. Spring; 314. Sphere; 32. Inner tube; 321. Annular groove; 33. Outer tube; 332. Disconnecting annular groove; 331. Operating window; 34. Limiting ring; 341. Annular blind groove; 342. Opening; 35. Locking sleeve; 36. Frame; 37. Rotating shaft; 38. Locking arm; 381. Arc block; 382. Insert block; 4. First electrical tape; 5. Filling layer; 6. Shielding layer; 8. Fire-resistant wrapping layer; 9. Outer sheath; 101. Support ring; 1011. Support groove; 102. Screw; 103. Nut; 104. Second electrical tape. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Example

[0016] like Figures 1 to 5 As shown, this embodiment provides a corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable comprising multiple cable cores 1, each cable core 1 being composed of multiple strands of copper conductors twisted together. Each cable core 1 is covered with an insulation layer 2, which is made of cross-linked polyethylene (XLPE) material and possesses excellent electrical insulation properties, heat resistance, and mechanical strength. The multiple cable cores 1 covered with the insulation layer 2 are regularly twisted together to form a cable. A filler layer 5 is provided in the gaps between the cables; the filler layer 5 can be made of a non-hygroscopic material to ensure the cable's roundness. The filler layer 5 is sequentially covered with a shielding layer 6, a fire-resistant wrapping layer 8, and an outer sheath 9. The shielding layer 6 can be a copper wire braided shield or an aluminum-plastic composite tape shield, used to resist external electromagnetic interference. The fire-resistant wrapping layer 8 can be made of mica tape, and the outer sheath 9 can be made of polyvinyl chloride (PVC) or polyolefin materials, providing overall protection and flame-retardant fire resistance.

[0017] A break point is pre-set along the path of each cable core 1, and a power-off mechanism 3 is installed at each break point. For example... Figure 3 , Figure 4 and Figure 5 As shown, each cable core 1 is divided into two sections at a specific position along its length, and the power-off mechanism 3 is connected between these two sections of cable core 1. When a cable core 1 is subjected to an axial tensile force exceeding a preset threshold due to external reasons (such as improper traction, equipment displacement, etc.), the corresponding power-off mechanism 3 will be triggered, automatically disconnecting the electrical connection of the cable core 1, thereby achieving active power-off protection.

[0018] The power-off mechanism 3 mainly includes an inner tube 32, an outer tube 33, and a locking sleeve 35. Both the inner tube 32 and the outer tube 33 are made of a highly conductive metal material (such as copper or a copper alloy). Figure 5 and Figure 6As shown, one end of the inner tube 32 is fixedly connected (e.g., crimped) to the conductor of a section of cable core 1 via a connecting pipe 31. One end of the outer tube 33 is also fixedly connected to the conductor of another section of cable core 1 via another connecting pipe 31. The inner tube 32 and the outer tube 33 are coaxially arranged, with the inner tube 32 inserted inside the outer tube 33. An annular boss 311 is coaxially arranged on the outer wall of the inner tube 32, located between the inner tube 32 and the outer tube 33. Multiple receiving grooves 312 are evenly formed along the circumference of the outer wall of the annular boss 311. A spring 313 is installed in each receiving groove 312, with one end of the spring 313 fixed to the bottom wall of the receiving groove 312 and the other end connected to a metal ball 314. In the initial state (i.e., when not under tension), the spring 313 is in a compressed or uncompressed state, causing a part of the ball 314 to protrude from the receiving groove 312. Its outer surface simultaneously abuts against the inner wall of the outer tube 33 and the side wall of the receiving groove 312, thereby forming a stable electrical connection path. Current flows from one section of cable core 1 into the inner tube 32 through the connecting pipe 31, is conducted to the outer tube 33 through the contact between the ball 314 and the outer tube 33, and then flows to another section of cable core 1 through another connecting pipe 31.

[0019] A discontinuity groove 332 is formed on the inner wall of the outer tube 33. The inner diameter of this discontinuity groove 332 is larger than the inner diameter of the main body of the outer tube 33. When the cable is subjected to abnormal axial tension, the inner tube 32 and the outer tube 33, which are connected between the two cable cores 1, will tend to undergo relative axial displacement. Figure 6 As shown, when the tension reaches a preset threshold, the inner tube 32 is pulled outward relative to the outer tube 33, and the annular boss 311 moves accordingly. Since the sphere 314 is initially confined outside the receiving groove 312 by the inner wall of the outer tube 33, when the annular boss 311 moves to a position where the sphere 314 is directly opposite the disconnecting annular groove 332, the sphere 314, freed from the radial constraint of the inner wall of the outer tube 33, is rapidly ejected radially inward under the elastic force of the spring 313, embedding itself into the disconnecting annular groove 332. At this point, the sphere 314 completely disengages from the inner wall of the outer tube 33, the current path is physically blocked, and automatic power-off is achieved. The preset tension threshold can be precisely designed and adjusted using the spring constant of the spring 313, the size of the sphere 314, and the angle of the annular boss 311.

[0020] To facilitate maintenance after a power outage or reconnection when needed, the power-off mechanism 3 is also equipped with a resettable locking structure. For example... Figures 5-8As shown, an annular groove 321 is formed on the outer wall of the inner tube 32, near the connecting tube 31. A limiting ring 34 is slidably fitted in the annular groove 321, and can slide within a small range along the axial direction of the inner tube 32, but its axial disengagement is restricted by the two side walls of the annular groove 321. A locking sleeve 35 is coaxially installed at the inner port of the outer tube 33, and one end face of the locking sleeve can be abutted with the end face of the limiting ring 34. An annular blind groove 341 is formed on the outer wall of the limiting ring 34, and at least one opening 342 is formed along the axial direction on the outer wall, which communicates with the annular blind groove 341. An operating window 331 is correspondingly formed on the wall of the outer tube 33. A frame 36 is fixedly installed outside the operating window, and a rotating shaft 37 is installed on the frame 36. A locking arm 38 that can rotate around the rotating shaft 37 is fitted on the rotating shaft 37. One end of the locking arm 38 extends into the operating window and is fixedly connected to an arc-shaped block 381 and at least one insert block 382.

[0021] When installing or needing to reconnect, insert the inner tube 32 into the outer tube 33. At this time, the operator can rotate the locking arm 38. Figure 7 As shown, when the locking arm 38 rotates to a specific position, its insert 382 passes through the opening 342 on the limiting ring 34 and extends into the annular blind groove 341. Simultaneously, the arc-shaped block 381 is engaged in the annular groove 321 of the inner tube 32. Subsequently, the limiting ring 34 is slightly rotated (this can be achieved by rotating the locking sleeve). Since the insert 382 has been inserted into the annular blind groove 341, when the limiting ring 34 rotates, the opening 342 and the insert 382 are misaligned circumferentially. The insert 382 is then engaged in the annular blind groove 341 and cannot exit from the opening 342, thereby locking the limiting ring 34 (i.e., the inner tube 32 and the outer tube 33) together axially, restoring the mechanical connection and electrical path. This process facilitates the quick connection and locking of the two cable core sections at the break point.

[0022] like Figure 2 and Figure 8 As shown, after the power-off mechanism 3 is installed, a first electrical tape (such as the first electrical tape 4) is tightly wrapped around the outer periphery of the power-off mechanism 3 and the adjacent two insulating layers 2 to ensure reliable insulation at this location. More preferably, a pressure sensor (not shown in the figure) can be embedded in the inner wall of the disconnecting ring groove 332. When the ball 314 is inserted into the disconnecting ring groove 332 under tension triggering, it will contact the pressure sensor and generate a pressure signal. This pressure sensor can communicate with a remote monitoring unit. After receiving the pressure signal, the monitoring unit can immediately send a command to the relevant circuit breaker or switching equipment to assist or double ensure that the current path is quickly and reliably blocked, while simultaneously realizing remote alarm and status monitoring of overload tension. The monitoring unit can be a PC computer, employing advanced technology, so further details are omitted.

[0023] To optimize installation and protect the power-off mechanism 3, such as Figure 1 , Figure 2 As shown, the power-off mechanism 3 includes two support rings 101, a screw 102, multiple fastening nuts 103, and the aforementioned cable. Each support ring 101 is made of insulating material, and its inner ring surface has multiple support grooves 1011 circumferentially formed, the number of support grooves 1011 corresponding to the number of cable cores 1 inside the cable. During installation, the two support rings 101 are respectively fitted onto both sides of the power-off mechanism 3 on the cable, so that each cable core 1 (along with its insulation layer 2) is precisely embedded in a support groove 1011, thereby separating and fixing the relative positions of the multiple cable cores 1 radially. The screw 102 passes through the corresponding holes on the two support rings 101 and is locked on both sides of each support ring 101 with fastening nuts 103, thereby firmly connecting the two support rings 101 into an integral frame. Finally, a second electrical tape 104 is used to wrap around the outer periphery of the first electrical tape 4 and the adjacent outer sheath 9, firmly binding and fixing the entire frame. After this installation, a heat dissipation cavity (not shown) is naturally formed between the two support rings 101 and the outer sheath 9 of the cable, which is beneficial for the heat dissipation of the power-off mechanism 3 and this section of the cable. More importantly, the above structure can bear and disperse the radial pressure that may be applied to the cable from the outside (such as being stepped on or squeezed), effectively avoiding the radial pressure from acting directly on the power-off mechanism 3 and affecting the accuracy of its axial tensile triggering function. At the same time, it can also prevent the cable from being damaged by excessive bending.

[0024] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A corrosion-resistant and tensile-strength cross-linked polyethylene overhead cable, comprising multiple cable cores (1), each of the cable cores (1) being covered with an insulation layer (2) on its outer periphery, characterized in that, A power-off mechanism (3) is provided at the break point of each cable core (1). When the cable core (1) is subjected to an axial tensile force exceeding a preset threshold, the power-off mechanism (3) is triggered and automatically disconnects the electrical connection of the cable core (1).

2. The corrosion-resistant, tensile-strength cross-linked polyethylene overhead cable according to claim 1, characterized in that, The power-off mechanism (3) includes an inner tube (32) and an outer tube (33); One end of the inner tube (32) and one end of the outer tube (33) are respectively connected to a connecting pipe (31), and the two connecting pipes (31) are respectively fixedly connected to the two sections of the cable core (1); The outer wall of the inner tube (32) is coaxially provided with an annular boss (311). The outer tube (33) is coaxially sleeved on the outside of the inner tube (32), and the annular boss (311) is located between the inner tube (32) and the outer tube (33); An annular groove (321) is provided on the outer wall of the inner tube (32) along its circumference, and a limiting ring (34) is slidably provided in the annular groove (321) along its axial direction. The outer wall of the annular boss (311) is provided with a plurality of receiving grooves (312) along its circumference. A spring (313) is provided in each receiving groove (312). One end of the spring (313) is connected to the bottom wall of the receiving groove (312), and the other end is connected to a ball (314). A portion of the sphere (314) extends out of the receiving groove (312) and abuts against the inner wall of the outer tube (33) and the side wall of the receiving groove (312); The inner wall of the outer tube (33) has a disconnecting annular groove (332). When the cable core (1) is subjected to the axial tension, the inner tube (32) and the outer tube (33) undergo relative axial displacement, causing the ball (314) to be embedded in the disconnection groove (332) to block the current path.

3. The corrosion-resistant, tensile-strength cross-linked polyethylene overhead cable according to claim 2, characterized in that, The outer ring wall of the limiting ring (34) has an annular blind groove (341), and at least one opening (342) is provided on the ring wall of the limiting ring (34) along the axial direction, the opening (342) communicating with the annular blind groove (341). The power-off mechanism (3) also includes a locking sleeve (35), which is coaxially disposed inside the outer tube (33), and one end of which is coaxially connected to the limiting ring (34); At least one operating window (331) is provided on the wall of the outer tube (33). A frame (36) is fixedly provided at the operating window (331). A rotating shaft (37) is provided on the frame (36). A locking arm (38) that can rotate around the rotating shaft (37) is sleeved on the rotating shaft (37). One end of the locking arm (38) extends into the operating window (331) and is fixedly connected to an arc-shaped block (381) and an insert (382). The insert (382) passes through the opening (342) and extends into the annular blind groove (341). The arc-shaped block (381) is located in the annular groove (321). When the limiting ring (34) rotates to the predetermined position, the insert (382) and the opening (342) are misaligned in the circumferential direction, so that the limiting ring (34) is locked between the inner tube (32) and the outer tube (33).

4. The corrosion-resistant, tensile-strength cross-linked polyethylene overhead cable according to claim 3, characterized in that, It also includes a first electrical tape (4), which is wrapped around the outer periphery of the power-off mechanism (3) and the adjacent insulating layer (2).

5. The corrosion-resistant, tensile-strength cross-linked polyethylene overhead cable according to claim 4, characterized in that, It also includes a filling layer (5), a shielding layer (6), a fire-resistant wrapping layer (8), and an outer sheath (9) that are sequentially wrapped around the outside of the insulation layer (2) from the inside out.

6. The corrosion-resistant, tensile-strength cross-linked polyethylene overhead cable according to claim 2, characterized in that, A pressure sensor is installed inside the disconnected annular groove (332); When the cable core (1) is subjected to the axial tension, the inner tube (32) and the outer tube (33) undergo relative axial displacement, causing the ball (314) to embed into the disconnection annular groove (332) and contact the pressure sensor; The pressure sensor is communicatively connected to a monitoring unit, which sends a command to block the current path based on the pressure signal.

7. The corrosion-resistant, tensile-strength cross-linked polyethylene overhead cable according to claim 5, characterized in that, The power-off mechanism (3) also includes two support rings (101), a screw (102), multiple fastening nuts (103) and a second electrical tape (104). Each of the support rings (101) is provided with a plurality of support grooves (1011) along the circumferential direction. The plurality of cable cores (1) correspond one-to-one with the plurality of support grooves (1011) and are embedded in the support grooves (1011). The screw (102) passes through two support rings (101), and each support ring (101) has a fastening nut (103) on both sides, and the fastening nut (103) is threadedly connected to the screw (102); The second electrical tape (104) is wrapped around the outer periphery of the first electrical tape (4) and the adjacent outer sheath (9), so that a heat dissipation cavity is formed between the two support rings (101).

Images