Intermediate cold contraction cable accessory for cross-linked polyethylene insulated power cable

Abstract

The invention relates to the technical field of cold-shrink cable accessories, and discloses a middle cold-shrink cable accessory for a cross-linked polyethylene insulated power cable, which comprises a cold-shrink connecting pipe and a pair of cables, a spiral bulge is arranged outside the cold-shrink connecting pipe, and a semi-conductive buffer layer, a cold-shrink insulating pipe and an outer shielding layer are sleeved outside the cold-shrink connecting pipe. The cable is composed of a conductor, a cross-linked polyethylene insulating layer and other multi-layer structures, T-shaped connecting pipes at the two ends of the cold shrinkage connecting pipe are connected with a conductor sealing inner cylinder through a clamping mechanism, and a sealing adhesive layer and a waterproof insulating adhesive tape layer are arranged outside the clamping mechanism. The outer side of the cable is provided with a semi-annular fixing clamp, and the cold contraction connecting pipe is coated with a metal armor layer and is connected with the fixing clamp. The accessory is installed in a cold contraction mode, a heating tool is not needed, installation is easy, convenient and rapid, installation time is greatly shortened, workload and accessory damage risks are reduced, and construction efficiency is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of cold-shrink cable accessories, in particular to an intermediate cold-shrink cable accessory for a cross-linked polyethylene insulated power cable. Background Art

[0002] Cross-linked polyethylene insulated power cables are widely used in power transmission due to their excellent electrical and mechanical properties. In cable lines, intermediate joints, as key components connecting cables, have a direct impact on the reliability and stability of the entire cable system. Cold-shrink cable accessories, with their advantages of easy installation and no need for heating, have found widespread use in practical projects.

[0003] However, there are still some problems in actual use: the sealing performance of traditional cold shrink cable accessories is limited. In a humid environment, moisture can easily penetrate into the cable connector, resulting in a decrease in insulation performance and causing electrical failures; its mechanical protection structure is insufficient. When squeezed or stretched by external force, the accessories are easily damaged, affecting the normal operation of the cable; moreover, the shielding effect of some cold shrink cable accessories is poor and cannot effectively resist external electromagnetic interference, affecting the quality of power transmission. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem of poor sealing of cold shrink cable accessories in the prior art, and to propose an intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable.

[0005] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions: An intermediate cold-shrink cable accessory for a cross-linked polyethylene insulated power cable, comprising a cold-shrink connecting tube and a pair of cables. The cold-shrink connecting tube is in the form of a hollow tube, the outer surface of which is provided with continuous spiral protrusions, and the outer side of the cold-shrink connecting tube is sequentially sheathed with a semi-conductive buffer layer, a cold-shrink insulating tube, and an outer shielding layer. The cable is composed of a conductor, a cross-linked polyethylene insulation layer, a semi-conductive shielding layer, a copper shielding layer and an outer sheath from the inside to the outside. A pair of T-shaped connecting tubes are fixedly provided at both ends of the cold shrink connecting tube. A conductor is inserted into the interior of each T-shaped connecting tube. A concentrically fixed sealing inner cylinder is sleeved on each conductor. Each sealing inner cylinder is connected to the T-shaped connecting tube on the same side through a snap-fit ​​mechanism. A sealing assembly is sleeved on the outer side of the locking mechanism, and the sealing assembly includes an inner sealing rubber layer and an outer waterproof insulating tape layer; A pair of semi-annular fixing clamps are provided on the outermost side of each cable, and the upper and lower ends of each pair of semi-annular fixing clamps are threadedly locked by bolt and nut assemblies. A metal armor layer is provided on the outermost side of the cold shrink connecting tube, and both ends of the metal armor layer are fixedly connected to the corresponding semi-annular fixing clamps.

[0006] Preferably, the cold shrink connecting tube is made of a conductive metal material, has a length of 150-250 mm, an inner diameter 2-5 mm larger than the conductor diameter, a height of the protrusion is 0.8-1.2 mm, and a pitch of 8-12 mm.

[0007] Preferably, the semi-conductive buffer layer is made of semi-conductive rubber material with a thickness of 2-3 mm and a length 50-100 mm longer than the cold shrink connecting tube; the cold shrink insulating tube is made of high-performance silicone rubber material with a wall thickness of 6-10 mm and a length of 800-1200 mm; the outer shielding layer is made of tinned copper mesh, the copper wire diameter of the tinned copper mesh is 0.1-0.2 mm, the mesh size is 2-3 mm × 2-3 mm, and the width is 150-250 mm.

[0008] Preferably, the conductor diameter is 10-30 mm, the cross-linked polyethylene insulation layer thickness is 4-8 mm, the semi-conductive shielding layer thickness is 0.5-1.5 mm, the copper shielding layer thickness is 0.1-0.3 mm, and the outer sheath thickness is 2-5 mm.

[0009] Preferably, the locking mechanism includes a positioning pin, a first annular cavity is opened on the locking end face of the sealing inner cylinder, a plurality of circularly distributed positioning pin holes are opened on the inner wall of the first annular cavity, a plurality of circularly distributed positioning pins are fixed on the locking end face of the T-shaped connecting tube, the locking end of the T-shaped connecting tube is inserted in the first annular cavity, and the positioning pins are adapted to be inserted in the corresponding positioning pin holes.

[0010] Preferably, the outer ring surface of the T-shaped connecting tube is provided with an annular groove, the cross-section of the annular groove is trapezoidal, and the inner ring surface of the first annular cavity is provided with a plurality of spherical center through holes, and the interior of each of the spherical center through holes is slidably fitted with a spherical bead, and the inner end face of each spherical bead is against the annular groove.

[0011] Preferably, the outer sliding sleeve of the sealing inner cylinder is provided with a sealing outer cylinder, and the interior of the sealing outer cylinder is provided with a second annular cavity, an annular boss, and an annular groove in sequence. The annular groove is sloped, and the outer end of each spherical card bead rests on the annular boss.

[0012] Preferably, a concentrically fixed retaining ring is sleeved on the sealing inner cylinder, a tension spring is fixed inside the second annular cavity, the tension spring is slidably sleeved on the outside of the sealing inner cylinder, and the other end of the tension spring is fixed to the fixed retaining ring.

[0013] Preferably, the sealant layer is made of hot-melt sealant, which is melted by heating, and the filling thickness of the sealant layer is controlled at 3-5mm. The waterproof insulating tape layer is wound in multiple layers, each tape width is 50-70mm, and 4-6 layers are wound. The overlap width between each layer is one-half to two-thirds of the tape width.

[0014] Preferably, the metal armor layer is formed by spirally winding a stainless steel strip with a thickness of 0.3-0.5 mm, a width of the stainless steel strip of 25-35 mm, an overlap width of 8-12 mm between the stainless steel strips, and a spacing between two pairs of semi-annular fixing clamps of 150-200 mm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, the sealing assembly composed of the inner sealant layer and the outer waterproof insulating tape layer effectively prevents water and moisture from invading the interior of the cable connector, thereby improving the reliability of the cable accessories in humid environments and reducing the risk of insulation performance degradation due to water intrusion; 2. In the present invention, the outermost metal armor layer is spirally wound with stainless steel tape, which has high strength and resistance to external impact, can effectively protect the internal insulation layer, shielding layer and other structures, reduce damage caused by external force extrusion, stretching, etc., and extend the service life of cable accessories; 3. In the present invention, the outer shielding layer is made of tinned copper mesh, which, together with the copper shielding layer of the cable, can more effectively shield external electromagnetic interference, ensure the stability and quality of power transmission, and reduce the impact of electromagnetic interference on the power system. In summary, the intermediate cold shrink cable accessory of the present invention adopts a cold shrink installation method, does not require heating tools, and the installation process is simple and quick, which reduces installation time and workload, improves construction efficiency, and also reduces the risk of accessory damage due to improper heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is an exploded schematic diagram of the overall structure of the present invention; Figure 3A schematic diagram of a pair of cables and a sealing assembly structure cut away and exploded in accordance with the present invention; Figure 4 Schematic diagram of the cross-section of the cold shrink connecting tube of the present invention; Figure 5 Schematic diagram of the exploded cross-section of the structure of the cold shrink connecting tube of the present invention; Figure 6 Schematic diagram of a cross-section of a pair of cables of the present invention; Figure 7 It is a schematic exploded cross-sectional view of the structure of a pair of cables of the present invention; Figure 8 Schematic diagram of the cross-section of the structure of the engaging mechanism of the present invention; Figure 9 It is a schematic exploded cross-sectional view of the structure of the engaging mechanism of the present invention; Serial numbers in the figure: 100, cold shrink connecting tube; 101, protrusion; 102, semi-conductive buffer layer; 103, cold shrink insulating tube; 104, outer shielding layer; 105, T-shaped connecting tube; 106, positioning pin; 107, annular groove; 200, conductor; 201, cross-linked polyethylene insulation layer; 202, semi-conductive shielding layer; 203, copper shielding layer; 204, outer sheath; 205, sealing inner cylinder; 206, first annular cavity; 207, spherical card bead; 208, sealing outer cylinder; 209, second annular cavity; 210, annular boss; 211, annular groove; 212, tension spring; 213, fixing ring; 300, sealing rubber layer; 301, waterproof insulating tape layer; 302, semi-annular fixing clamp; 303, metal armor layer; 304, bolt and nut assembly. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] Example 1: This example provides an intermediate cold shrink cable accessory for a cross-linked polyethylene insulated power cable. Figures 1-9 Specifically, it includes a cold shrink connection tube 100 and a pair of cables. The cold shrink connection tube 100 is in the shape of a hollow tube. The outer surface of the cold shrink connection tube 100 is provided with a continuous spiral protrusion 101. The cold shrink connection tube 100 is made of a conductive metal material (such as oxygen-free copper with a purity of 99.9% or a high-strength aluminum alloy). Its inner diameter is 2-5 mm larger than the diameter of the conductor 200 to facilitate smooth insertion of the conductor 200. The length is 150-250 mm to ensure sufficient connection length after the conductor 200 is docked. The height of the protrusion 101 is 0.8-1.2 mm, and the pitch is 8-12 mm. This design greatly increases the friction and adhesion between the cold shrink connection tube 100 and the subsequent coating layer. The outer side of the cold shrink connection tube 100 is sequentially sheathed with a semi-conductive buffer layer 102, a cold shrink insulation tube 103, and an outer shielding layer 104. The semi-conductive buffer layer 102 is made of a semi-conductive rubber material, has a thickness of 2-3mm, and is 50-100mm longer than the cold shrink connection tube 100. Its function is to buffer electric field stress and prevent damage to the insulation layer caused by electric field concentration. The cold shrink insulation tube 103 is made of a high-performance silicone rubber material, has a wall thickness of 6-10mm, and is 800-1200mm long, and has excellent electrical insulation properties and elastic recovery force. The outer shielding layer 104 is made of tinned copper mesh. The copper wire diameter of the tinned copper mesh is 0.1-0.2mm, the mesh size is 2-3mm×2-3mm, and the width is 150-250mm. After being wrapped around the outer layer, it can effectively shield electromagnetic interference and ensure the stability of power transmission. The cable consists of a conductor 200, a cross-linked polyethylene insulation layer 201, a semi-conductive shielding layer 202, a copper shielding layer 203, and an outer sheath 204, from the inside out. The diameter of the conductor 200 is 10-30 mm, depending on the rated current carrying capacity and voltage level of the cable. The cross-linked polyethylene insulation layer 201 is 4-8 mm thick to ensure good electrical insulation performance. The semi-conductive shielding layer 202 is 0.5-1.5 mm thick to provide a uniform electric field. The copper shielding layer 203 is 0.1-0.3 mm thick to shield the electric field and short-circuit current path. The outer sheath 204 is 2-5 mm thick to provide mechanical protection and moisture resistance. A pair of T-shaped connecting tubes 105 are fixedly provided at both ends of the cold shrink connecting tube 100. A conductor 200 is inserted through the interior of each T-shaped connecting tube 105. The inner wall of the cold shrink connecting tube 100 fits tightly with the conductor 200, achieving a reliable electrical connection between the conductors 200 through the cold shrinkage force. Each conductor 200 is concentrically fixedly sleeved with a sealed inner cylinder 205, and each sealed inner cylinder 205 is connected to the T-shaped connecting tube 105 on the same side through a snap-fit ​​mechanism. A sealing assembly is sleeved on the outside of the locking mechanism. The sealing assembly includes an inner sealant layer 300 and an outer waterproof insulation tape layer 301. The sealant layer 300 uses hot-melt sealant, which is melted by heating during installation. The thickness of the sealant layer 300 is controlled to be 3-5mm, filling the gap between the cable and the accessories to achieve a good sealing effect. The waterproof insulation tape layer 301 is wound in multiple layers, each with a width of 50-70mm. 4-6 layers are wound, and the overlap width between each layer is one-half to two-thirds of the tape width, further enhancing the waterproof performance while providing additional insulation protection. A pair of semi-annular fixing clamps 302 are provided on the outermost side of each cable, and the upper and lower ends of each pair of semi-annular fixing clamps 302 are threadedly locked by bolt and nut assemblies 304. A metal armor layer 303 is provided on the outermost side of the cold shrink connecting tube 100, and both ends of the metal armor layer 303 are fixedly connected to the corresponding semi-annular fixing clamps 302; in order to enhance the mechanical protection performance of the cable accessories, the metal armor layer 303 is spirally wound with a stainless steel belt with a thickness of 0.3-0.5mm, the width of the stainless steel belt is 25-35mm, the overlap width between the stainless steel belts is 8-12mm, and the spacing between the two pairs of semi-annular fixing clamps 302 is 150-200mm, forming a sturdy mechanical protection structure that can effectively resist large external mechanical impact forces.

[0019] It should be noted that: in this embodiment, if Figure 8 and Figure 9 As shown, the locking mechanism includes a positioning pin 106. A first annular cavity 206 is formed on the locking end surface of the sealing inner cylinder 205. A plurality of circularly distributed positioning pin holes are formed on the inner wall of the first annular cavity 206. A plurality of circularly distributed positioning pins 106 are fixed on the locking end surface of the T-shaped connecting tube 105. The locking end of the T-shaped connecting tube 105 is inserted into the first annular cavity 206, and the positioning pins 106 are adapted to be inserted into the corresponding positioning pin holes. The outer annular surface of the T-shaped connecting tube 105 is provided with an annular groove 107, the cross section of which is trapezoidal. The inner annular surface of the first annular cavity 206 is provided with a plurality of spherical through holes, each of which is slidably fitted with a spherical bead 207, and the inner end surface of each spherical bead 207 abuts against the annular groove 107. The outer sliding sleeve of the sealing inner cylinder 205 is provided with a sealing outer cylinder 208. The interior of the sealing outer cylinder 208 is provided with a second annular cavity 209, an annular boss 210, and an annular groove 211 in sequence. The annular groove 211 is sloped, and the outer end of each spherical card bead 207 abuts against the annular boss 210. A concentrically fixed retaining ring 213 is sleeved on the sealing inner cylinder 205 , and a tension spring 212 is fixed inside the second annular cavity 209 . The tension spring 212 is slidably sleeved on the outside of the sealing inner cylinder 205 , and the other end of the tension spring 212 is fixed to the fixed retaining ring 213 .

[0020] The operation steps of the locking mechanism are as follows: Slide the sealing outer cylinder 208 along the compression direction of the tension spring 212 to shrink the tension spring 212. At this time, the annular groove 211 is aligned with the spherical center through hole, preparing for the insertion of the T-shaped connecting tube 105. Insert the engaging end of the T-shaped connecting tube 105 into the first annular cavity 206, ensuring that the positioning pin 106 is accurately embedded in the corresponding positioning pin hole to achieve initial positioning; Continue to push the T-shaped connecting tube 105 forward, and its engaging end squeezes the spherical clamping bead 207 to slide outward along the spherical center through hole until the outer end of the spherical clamping bead 207 hits the slope area of ​​the annular groove 211; When the sealing outer cylinder 208 is released, the tension of the tension spring 212 drives the sealing outer cylinder 208 to reset. Due to the slope structure of the annular groove 211, the spherical clamping bead 207 is squeezed inward and embedded in the trapezoidal cross-section of the annular groove 107. At this time, the inner annular surface of the annular boss 210 is aligned with the spherical center through hole, forming a mechanical lock to prevent the spherical clamping bead 207 from falling out. Check whether the sealing outer cylinder 208 is completely reset and whether the spherical card bead 207 is tightly inserted into the annular groove 107 to ensure the axial and radial positioning accuracy of the sealing inner cylinder 205 and the T-shaped connecting pipe 105.

[0021] The working principle of this embodiment is as follows: Cable pretreatment: First, the outer sheath 204, copper shield 203, semi-conductive shield 202, and cross-linked polyethylene insulation 201 of the two cables are stripped to the specified length. During the stripping process, the cuts must be neat to avoid damaging the conductors 200 and the cross-linked polyethylene insulation 201. The sealing inner barrel 205 is then fixed and installed at the cuts. Then, the conductors 200 are cleaned and polished to remove the surface oxide layer and impurities to ensure good conductivity of the conductor 200 connection. Pretreatment of the cold shrink connecting tube 100: Fix the two ends of the cold shrink connecting tube 100 to a pair of T-shaped connecting tubes 105, evenly apply a layer of semi-conductive silicone grease on the outer surface of the cold shrink connecting tube 100, and then put the semi-conductive buffer layer 102 on the cold shrink connecting tube 100. Adjust the position of the semi-conductive buffer layer 102 so that it completely covers the cold shrink connecting tube 100; The cold shrink insulation tube 103 is placed on the semi-conductive buffer layer 102 and expanded using an expansion tool. In the expanded state, the cold shrink insulation tube 103 is moved to a suitable position. Then, the expansion tool is slowly released, and the cold shrink insulation tube 103 shrinks and fits tightly on the semi-conductive buffer layer 102, providing stable insulation performance. The outer shielding layer 104 made of tinned copper mesh is wound on the cold shrink insulation tube 103 in a certain direction and manner to achieve a good electromagnetic shielding effect. After the winding is completed, the two ends of the outer shielding layer 104 are tied and fixed with copper wire; Installation of the snap-fit ​​mechanism: Use a dedicated expansion tool to expand the cold shrink connection tube 100 to an appropriate diameter. Insert the conductors 200 of the two cables into the cold shrink connection tube 100 through a pair of T-shaped connection tubes 105, respectively, to connect the two conductors 200. After the connection is completed, slowly release the expansion tool. The cold shrink connection tube 100 will tightly wrap around the conductor 200 by its own elastic contraction force, achieving a reliable connection between the conductors 200. Then, snap-fit ​​the sealing inner tube 205 and the T-shaped connection tube 105 together. Installation of the sealing assembly: First, evenly apply a layer of hot-melt sealant to the outside of the sealing outer cylinder 208. Then, heat the sealant with a heating tool to melt it and fill the gap. Before the sealant layer 300 is completely cured, quickly wrap the waterproof insulation tape layer 301 around it. Wrap multiple layers to ensure a tight fit and enhance the sealing and insulation performance. Installation of the metal armor layer 303: Wrap the stainless steel belt in a spiral manner on the outermost layer of the connection between a pair of cables, overlapping each other by a certain width, and use two pairs of semi-annular fixing clamps 302 to fix them on the pair of cables respectively, and firmly fix the two ends of the stainless steel belt to form a solid mechanical protection structure.

[0022] Example 2: Based on Example 1, the dimensions used in this example are different, but the rest of the structure is the same. The specific working principle is as follows: Cable pretreatment: First, select two 8m long cables and use cable stripping equipment to accurately strip the outer sheath 204 to 800mm, the copper shielding layer 203 to 600mm, the semi-conductive shielding layer 202 to 400mm, and the cross-linked polyethylene insulation layer 201 to 300mm. During the stripping process, ensure that the incision is neat to avoid damaging the conductor 200 and the cross-linked polyethylene insulation layer 201; and fix the sealing inner cylinder 205 at the incision. Then, perform ultrasonic cleaning on the conductor 200 to remove the surface oxide layer and impurities, and then blow dry with a hair dryer to ensure good conductivity of the conductor 200 connection; Pretreatment of the cold shrink connection tube 100: Use an aluminum alloy cold shrink connection tube 100, fix the two ends of the cold shrink connection tube 100 to a pair of T-shaped connection tubes 105, and evenly apply a layer of semi-conductive silicone grease with a thickness of 0.3mm on the outer surface of the cold shrink connection tube 100. Then, put a semi-conductive buffer layer 102 on the cold shrink connection tube 100 with a length of 250mm. Adjust the position of the semi-conductive buffer layer 102 so that it completely covers the cold shrink connection tube 100; Select a 600mm long cold-shrink insulation tube 103 and place it over the semi-conductive buffer layer 102. Similarly, expand the cold-shrink insulation tube 103 using an expansion tool. While expanded, move the cold-shrink insulation tube 103 to a suitable position. Then, slowly release the expansion tool. The cold-shrink insulation tube 103 shrinks and fits tightly against the semi-conductive buffer layer 102, providing stable insulation performance. After shrinking, inspect the appearance of the cold-shrink insulation tube 103 to ensure it is free of defects such as bubbles and cracks. An outer shielding layer 104 made of tinned copper mesh with a width of 40 mm is wound around the cold shrink insulation tube 103 in a certain direction and manner, with a winding spacing of 6 mm to achieve a good electromagnetic shielding effect. After the winding is completed, the ends of the outer shielding layer 104 are tied and fixed with copper wire; Installation of the locking mechanism: Use a hydraulic expansion tool to expand the cold shrink connection tube 100 to an appropriate diameter, insert the conductors 200 of the two cables into the cold shrink connection tube 100 through a pair of T-shaped connection tubes 105, and dock the two conductors 200. After docking, slowly release the expansion tool to shrink and secure the cold shrink connection tube 100. Detect the temperature rise at the connection part of the conductors 200. Under normal load current, the temperature rise does not exceed the specified value. The cold shrink connection tube 100 relies on its own elastic contraction force to tightly wrap around the conductors 200, achieving a reliable connection of the conductors 200. Then, operate to lock and install the sealing inner tube 205 and the T-shaped connection tube 105. Installation of the sealing assembly: First, evenly apply a layer of hot-melt sealant with a thickness of 1.5 mm on the outside of the sealing outer cylinder 208. Then, heat the sealant with a heating tool to 110°C to melt the sealant and fill the gap. Before the sealant layer 300 is completely cured, quickly wrap the waterproof insulation tape layer 301 around it. Wrap four layers, multiple layers, and ensure a tight fit to enhance the sealing and insulation performance. Installation of the metal armor layer 303: Wrap a 25mm wide stainless steel belt in a spiral manner around the outermost layer of a pair of cable connections. The stainless steel belts overlap each other with an overlap width of 8mm. Use two pairs of semi-annular fixing clips 302 to fix them to the pair of cables respectively, and firmly fix the two ends of the stainless steel belts to form a solid mechanical protection structure.

[0023] Example 3: Based on Example 1, this example uses different dimensions, but the rest of the structure is the same. The specific working principle is as follows: Cable pretreatment: First, select two cables with a length of 10m. Use cable stripping equipment to accurately strip the outer sheath 204 to a length of 1000mm, the copper shielding layer 203 to a length of 800mm, the semi-conductive shielding layer 202 to a length of 600mm, and the cross-linked polyethylene insulation layer 201 to a length of 500mm. During the stripping process, ensure that the incision is neat to avoid damaging the conductor 200 and the cross-linked polyethylene insulation layer 201; and fix the sealing inner cylinder 205 at the incision. Then, clean and polish the conductor 200. Use sandpaper to polish off the oxide layer on the surface of the conductor 200, and then wipe the surface of the conductor 200 with anhydrous ethanol to remove impurities and ensure good conductivity of the conductor 200 connection. Pretreatment of the cold shrink tubing 100: Select a suitable model of cold shrink tubing 100 made of high-purity copper. Secure the two ends of the cold shrink tubing 100 to a pair of T-shaped connectors 105. Apply a 0.5mm thick layer of semi-conductive silicone grease evenly to the outer surface of the cold shrink tubing 100. Then, place a 300mm long semi-conductive buffer layer 102 on the cold shrink tubing 100. Adjust the position of the semi-conductive buffer layer 102 so that it completely covers the cold shrink tubing 100. A cold-shrink insulation tube 103 with a length of 800 mm was selected and placed on the semi-conductive buffer layer 102. The cold-shrink insulation tube 103 was also expanded using an expansion tool. In the expanded state, the cold-shrink insulation tube 103 was moved to a suitable position. Then, the expansion tool was slowly released, and the cold-shrink insulation tube 103 was shrunk and tightly fitted on the semi-conductive buffer layer 102. The insulation resistance of the cold-shrink insulation tube 103 was measured using an insulation resistance tester. The insulation resistance value was greater than 10,000 MΩ. An outer shielding layer 104 made of tinned copper mesh with a width of 50 mm is wound around the cold shrink insulation tube 103 in a certain direction and manner, with a winding spacing of 5 mm to achieve a good electromagnetic shielding effect. After the winding is completed, the ends of the outer shielding layer 104 are tied and fixed with copper wire; Installation of the locking mechanism: Use a hydraulic expansion tool to expand the cold shrink connection tube 100 to 1.5 times the diameter of the conductor 200. Insert the conductors 200 of the two cables into the cold shrink connection tube 100 through a pair of T-shaped connection tubes 105, respectively, to dock the two conductors 200. After docking, slowly release the expansion tool to shrink and secure the cold shrink connection tube 100. Measure the resistance of the connection part of the conductor 200. The resistance value meets the standard requirements. The cold shrink connection tube 100 relies on its own elastic contraction force to tightly wrap around the conductor 200, achieving a reliable connection of the conductor 200. Then, engage the sealing inner tube 205 with the T-shaped connection tube 105 through operation. Installation of the sealing assembly: First, evenly apply a 2mm thick layer of hot-melt sealant to the outside of the sealing outer cylinder 208. Use a heat gun to heat the sealant at approximately 120°C to melt the sealant and fill the gap. Before the sealant layer 300 is fully cured, quickly wrap the waterproof insulating tape layer 301 around it. Wrap five layers, with the overlap width between each layer being 1 / 2 the tape width. Wrap multiple layers to ensure a tight fit and enhance sealing and insulation performance. Installation of the metal armor layer 303: Wrap a 30mm wide stainless steel belt in a spiral manner around the outermost layer of a pair of cable connections, overlapping each other with an overlap width of 10mm. Use two pairs of semi-annular fixing clips 302 to fix them to the pair of cables respectively, and firmly fix the two ends of the stainless steel belt to form a solid mechanical protection structure.

[0024] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An intermediate cold shrink cable accessory for a cross-linked polyethylene insulated power cable, comprising a cold shrink connecting tube (100) and a pair of cables, characterized in that: The cold shrink connecting tube (100) is in the shape of a hollow tube, the outer surface of the cold shrink connecting tube (100) is provided with a continuous spiral protrusion (101), and the outer side of the cold shrink connecting tube (100) is sequentially sleeved with a semi-conductive buffer layer (102), a cold shrink insulating tube (103) and an outer shielding layer (104); The cable is composed of a conductor (200), a cross-linked polyethylene insulation layer (201), a semi-conductive shielding layer (202), a copper shielding layer (203), and an outer sheath (204) in order from the inside to the outside; A pair of T-shaped connecting tubes (105) are fixedly provided at both ends of the cold shrink connecting tube (100), a conductor (200) is inserted into the interior of each T-shaped connecting tube (105), and a concentrically fixed sealing inner tube (205) is sleeved on each conductor (200), and each sealing inner tube (205) is connected to the T-shaped connecting tube (105) on the same side via a snap-fit ​​mechanism; A sealing assembly is sleeved on the outer side of the locking mechanism, and the sealing assembly comprises an inner sealing rubber layer (300) and an outer waterproof insulating tape layer (301); A pair of semi-annular fixing clamps (302) are provided on the outermost side of each cable, and the upper and lower ends of each pair of semi-annular fixing clamps (302) are threadedly locked by bolt and nut assemblies (304); a metal armor layer (303) is provided on the outermost side of the cold shrink connection tube (100), and both ends of the metal armor layer (303) are fixedly connected to the corresponding semi-annular fixing clamps (302).

2. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 1, characterized in that: The shrinkable connecting tube (100) is made of a conductive metal material, has a length of 150-250 mm, and an inner diameter 2-5 mm larger than the diameter of the conductor (200). The height of the protrusion (101) is 0.8-1.2 mm, and the pitch is 8-12 mm.

3. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 2, characterized in that: The semi-conductive buffer layer (102) is made of a semi-conductive rubber material, has a thickness of 2-3 mm, and is 50-100 mm longer than the cold shrink connection tube (100); the cold shrink insulation tube (103) is made of a high-performance silicone rubber material, has a wall thickness of 6-10 mm, and is 800-1200 mm long; the outer shielding layer (104) is made of a tinned copper mesh, the copper wire diameter of the tinned copper mesh is 0.1-0.2 mm, the mesh size is 2-3 mm×2-3 mm, and the width is 150-250 mm.

4. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 3, characterized in that: The conductor (200) has a diameter of 10-30 mm, the cross-linked polyethylene insulation layer (201) has a thickness of 4-8 mm, the semi-conductive shielding layer (202) has a thickness of 0.5-1.5 mm, the copper shielding layer (203) has a thickness of 0.1-0.3 mm, and the outer sheath (204) has a thickness of 2-5 mm.

5. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 4, characterized in that: The locking mechanism includes a positioning pin (106), a first annular cavity (206) is provided on the locking end surface of the sealing inner cylinder (205), a plurality of circularly distributed positioning pin holes are provided on the inner wall of the first annular cavity (206), a plurality of circularly distributed positioning pins (106) are fixed on the locking end surface of the T-shaped connecting tube (105), the locking end of the T-shaped connecting tube (105) is inserted into the first annular cavity (206), and the positioning pins (106) are adapted to be inserted into the corresponding positioning pin holes.

6. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 5, characterized in that: The outer annular surface of the T-shaped connecting tube (105) is provided with an annular groove (107), the cross section of the annular groove (107) is trapezoidal, and the inner annular surface of the first annular cavity (206) is provided with a plurality of spherical through holes, each of the spherical through holes is provided with a spherical clamping bead (207) in a sliding fit, and the inner end surface of each spherical clamping bead (207) is against the annular groove (107).

7. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 6, characterized in that: The outer sliding sleeve of the sealing inner cylinder (205) is provided with a sealing outer cylinder (208), and the interior of the sealing outer cylinder (208) is provided with a second annular cavity (209), an annular boss (210), and an annular groove (211) in sequence. The annular groove (211) is sloped, and the outer end of each spherical card bead (207) abuts against the annular boss (210).

8. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 7, characterized in that: A concentrically fixed fixed retaining ring (213) is sleeved on the sealing inner cylinder (205), and a tension spring (212) is fixed inside the second annular cavity (209). The tension spring (212) is slidably sleeved on the outside of the sealing inner cylinder (205), and the other end of the tension spring (212) is fixedly connected to the fixed retaining ring (213).

9. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 8, characterized in that: The sealant layer (300) is made of hot-melt sealant, which is melted by heating. The thickness of the sealant layer is controlled to be 3-5 mm. The waterproof insulating tape layer (301) is wound in multiple layers, each tape layer has a width of 50-70 mm, and 4-6 layers are wound. The overlap width between each layer is one-half to two-thirds of the tape width.

10. The intermediate cold shrink cable accessory for cross-linked polyethylene insulated power cable according to claim 9, characterized in that: The metal armor layer (303) is formed by spirally winding a stainless steel strip with a thickness of 0.3-0.5 mm. The width of the stainless steel strip is 25-35 mm. The overlap width between the stainless steel strips is 8-12 mm. The spacing between the two pairs of semi-annular fixing clamps (302) is 150-200 mm.

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