Moisture resistant cable

Abstract

This utility model discloses a moisture-proof cable, including a cable core. The cable core is sequentially covered from the inside out with a cable core shielding layer, an inner insulation layer, an insulation shielding layer, a flame-retardant layer, a color-developing coating, a water-blocking layer, a water-absorbing and expanding layer, a support layer, and an outer protective layer. Several grooves are formed on the outer surface of the support layer, arranged in a circular array along the axial direction of the cable core. A water-soluble sealing film is provided at the groove opening, and the grooves are filled with repair material. A water-guiding channel is provided on the support layer, with one end connected to the outer protective layer and the other end connected to the water-absorbing and expanding layer. An expansion cavity is provided on the inner wall of the support layer, corresponding to the bottom of the groove. This utility model uses the water-blocking layer as a passive water-blocking barrier and the water-absorbing and expanding layer as an active water-blocking barrier, which expands upon contact with water to seal gaps. Simultaneously, the water-guiding channel and the water-absorbing and expanding layer work together to drive the repair material stored in the grooves of the support layer, forming a closed-loop self-repairing system, effectively blocking water and preventing moisture.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, specifically to a moisture-proof cable. Background Technology

[0002] During cable installation, scratches often cause the outer sheath to crack. If the cable is frequently submerged in water for short or long periods, or is in a humid environment, the cracked outer sheath will gradually absorb moisture from the environment, affecting the cable's lifespan and posing a significant safety hazard.

[0003] Chinese patent announcement CN 222813343 U discloses a water-blocking and moisture-proof power cable, including an abrasion-resistant layer, a support layer inside the abrasion-resistant layer, a water-absorbing and expanding layer inside the support layer, a water-blocking layer inside the water-absorbing and expanding layer, a flame-retardant layer inside the water-blocking layer, a moisture-proof layer inside the flame-retardant layer, a filling layer inside the moisture-proof layer, and a plurality of insulating layers inside the filling layer. This patented technology, by incorporating a wear-resistant layer, mitigates cable surface cracking caused by abrasion. A support layer further supports the cable, preventing cracking due to bending. The combination of a water-absorbing expansion layer, a water-blocking layer, a moisture-proof layer, and a filling layer provides multiple layers of waterproofing and moisture protection for the cable core. However, due to uncertainties in the construction process, the wear-resistant layer cannot completely prevent cracking. For example, sharp stones in the soil or uneven compaction of the backfill during installation can cause localized compression damage. If cracks are not repaired promptly, moisture can continuously penetrate the cable and, under the influence of the electric field, generate a large amount of water treeing, still posing a safety hazard. Utility Model Content

[0004] The main purpose of this utility model is to overcome the defects of the above-mentioned background technology and provide a moisture-proof cable.

[0005] To achieve the above objectives, this utility model proposes a moisture-proof cable, comprising a cable core, the outer surface of which is covered with a cable core shielding layer, the outer surface of which is covered with an inner insulation layer, the outer surface of which is covered with an insulating shielding layer, the outer surface of which is covered with a flame-retardant layer, the outer surface of which is coated with a color-developing coating, the outer surface of which is covered with a water-blocking layer, the outer surface of which is covered with a water-absorbing and expanding layer, the outer surface of which is covered with a support layer, and the outer surface of which is covered with an outer protective layer. A plurality of grooves are formed on the outer surface of the support layer, and these grooves are arranged in a circular array along the axial direction of the cable core. A water-soluble sealing film is provided at the opening of each groove, and the grooves are filled with repair material. A water-guiding channel is provided on the support layer, one end of which communicates with the outer protective layer, and the other end of which communicates with the water-absorbing and expanding layer. An expansion-accommodating cavity is provided on the inner wall of the support layer, and the expansion-accommodating cavity corresponds to the bottom of each groove. By using a water-blocking layer as passive radial waterproofing and a water-absorbing and expanding layer that expands upon contact with water as active longitudinal waterproofing, the expansion force generated during the expansion process of the water-absorbing and expanding layer drives the repair material stored in the groove of the support layer to be squeezed out and self-healed from the cracks in the outer protective layer, thus achieving the effects of water blocking and moisture prevention and improving the durability of the cable.

[0006] To further optimize the technical solution, the cable core includes several stranded conductors, each conductor having a double-sided insulating water-blocking tape on its outer side, and the gaps between the stranded conductors are filled with water-blocking powder. The combined use of the double-sided insulating water-blocking tape and the water-blocking powder provides longitudinal waterproofing to the cable core.

[0007] To further optimize the technical solution, the cross-section of the conductor is shaped like a fan or a tile. This fan or tile shape helps reduce the gap between the conductors during stranding.

[0008] To further optimize the technical solution, the cable core also includes a wrapping shielding layer. This shielding layer wraps around the outer surface of the stranded conductors, and the cable core shielding layer covers the outer surface of the wrapping shielding layer. The wrapping shielding layer prevents material from entering the gaps in the cable core during the extrusion of the cable core shielding layer.

[0009] To further optimize the technical solution, the outer protective layer includes an outer insulation layer and a wear-resistant layer. The outer insulation layer covers the outer surface of the support layer, and the wear-resistant layer covers the outer surface of the outer insulation layer. The wear-resistant layer and the outer insulation layer further enhance the protective capability of the cable's outer layer.

[0010] To further optimize the technical solution, the outer insulation layer is made of polyethylene, the wear-resistant layer is made of nitrile rubber, and the outer protective layer is made by double-layer co-extrusion of polyethylene and nitrile rubber.

[0011] To further optimize the technical solution, the support layer is made of polyurethane rubber extrusion.

[0012] To further optimize the technical solution, the material of the water-absorbing and swelling layer is superabsorbent resin, and the material of the water-blocking layer is aluminum-plastic composite tape.

[0013] To further optimize the technical solution, the color-developing coating is made by coating the outer surface of the insulating shielding layer with anhydrous cobalt chloride and water-absorbing resin.

[0014] To further optimize the technical solution, the cable core shielding layer and the insulating shielding layer are both made of semi-conductive shielding material, the inner insulating layer is made of water-tree resistant cross-linked polyethylene, and the cable core shielding layer, the inner insulating layer and the insulating shielding layer are three layers co-extruded.

[0015] The beneficial effects of this invention include: when the outer protective layer is cracked or damaged, external moisture enters the outer protective layer along the damaged area. The water-soluble sealing membrane hydrolyzes upon encountering the moisture, releasing the repair material stored inside the groove. The moisture can quickly enter the water-absorbing expansion layer along the water-conducting channel. The water-absorbing expansion layer expands upon encountering water, rapidly filling the gap between the water-absorbing expansion layer and the support layer, forming an active water barrier. The radial expansion pressure generated by the expansion material in the expansion chamber of the water-absorbing expansion layer squeezes the bottom of the groove, forcing the repair material into the crack of the outer protective layer for self-healing and repair, preventing further moisture intrusion, thereby achieving the effect of water blocking and moisture prevention. This invention uses the water-blocking layer as a passive water barrier and the water-absorbing expansion layer as an active water barrier upon encountering water. At the same time, the water-conducting channel and the water-absorbing expansion layer work together to drive the repair material to form a closed-loop self-repairing system, which conforms to the tiered water blocking concept of modern moisture-proof cables. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the moisture-proof cable in this embodiment of the utility model.

[0017] Figure 2 This is a schematic diagram of the cross-section of the conductor in an embodiment of this utility model.

[0018] Reference numerals: 1. Cable core; 101. Conductor; 102. Double-sided insulating water-blocking tape; 103. Wrapping shielding layer; 2. Cable core shielding layer; 3. Inner insulation layer; 4. Insulating shielding layer; 5. Flame retardant layer; 6. Color-developing coating; 7. Water-blocking layer; 8. Water-absorbing and expanding layer; 9. Supporting layer; 901. Groove; 902. Water-soluble sealing membrane; 903. Water-conducting channel; 904. Expansion cavity; 10. Outer protective layer; 1001. Outer insulation layer; 1002. Wear-resistant layer. Detailed Implementation

[0019] To make the technical problems, technical solutions, and beneficial effects of the embodiments of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0020] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be for both fixing and circuit connection purposes.

[0021] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] Please see Figure 1 and Figure 2The moisture-proof cable disclosed in this embodiment includes a cable core 1, a cable core shielding layer 2 covering the outer surface of the cable core 1, an inner insulation layer 3 covering the outer surface of the cable core shielding layer 2, an insulating shielding layer 4 covering the outer surface of the inner insulation layer 3, a flame-retardant layer 5 covering the outer surface of the insulating shielding layer 4, a color-developing coating 6 coating the outer surface of the flame-retardant layer 5, the color-developing coating 6 changing color upon contact with water, used to quickly determine whether water has entered the cable joint during cable construction, a water-blocking layer 7 covering the outer surface of the color-developing coating 6, a water-absorbing and expanding layer 8 covering the outer surface of the water-absorbing and expanding layer 7, a support layer 9 covering the outer surface of the water-absorbing and expanding layer 8, and an outer protective layer 10 covering the outer surface of the support layer 9. A plurality of grooves 901 are formed on the outer surface of the support layer 9. The grooves 901 are arranged in a ring array along the axial direction of the cable core 1. A water-soluble sealing membrane 902 is provided at the groove opening of the groove 901. The water-soluble sealing membrane 902 is made of polyvinyl alcohol with plasticizers, surfactants, modifiers and other additives. It can dissolve quickly when it comes into contact with water. The groove 901 is filled with repair material, which is a mixture of polyurethane insulating resin and rubber adhesive. A water guiding channel 903 is provided on the support layer 9, avoiding the groove 901. One end of the water guiding channel 903 is connected to the outer protective layer 10, and the other end of the water guiding channel 903 is connected to the water-absorbing expansion layer 8. An expansion receiving cavity 904 is provided on the inner wall of the support layer 9. The opening of the expansion receiving cavity 904 faces the water-absorbing expansion layer 8, and the top of the expansion receiving cavity 904 corresponds to the bottom of the groove 901. Specifically, the support layer 9 is made of polyurethane rubber extrusion, the water-absorbing and swelling layer 8 is made of super absorbent resin, and the radial expansion pressure is 0.2-0.5MPa, which can compress a certain thickness of polyurethane rubber to deform. The water-blocking layer 7 is made of aluminum-plastic composite tape, and the color-developing coating 6 is anhydrous cobalt chloride and water-absorbing resin composite coated on the outer surface of the insulating shielding layer 4. It is blue in the anhydrous state and turns pink when it comes into contact with water, making it easy to directly judge whether water has entered by the naked eye.In this embodiment, when the outer protective layer 10 is cracked or damaged, external moisture enters the outer protective layer 10 along the damaged area. When the moisture encounters the water-soluble sealing membrane 902, it hydrolyzes, releasing the repair material stored inside the groove 901. Simultaneously, the moisture quickly enters the water-absorbing expansion layer 8 along the water-guiding channel 903. The water-absorbing expansion layer 8 expands upon contact with water, rapidly filling the gap between the water-absorbing expansion layer 8 and the support layer 9 and entering the expansion receiving cavity 904. The radial expansion pressure generated by the water-absorbing expansion layer 8 within the expansion receiving cavity 904 compresses the bottom of the support layer 9. Due to the groove 901... The thickness between the bottom of the groove 1 and the expansion cavity 904 is small. The expansion pressure compresses the bottom of the groove 901 of the support layer 9, causing deformation and squeezing the repair material into the crack of the outer protective layer 10 for repair, preventing moisture from continuing to invade, thus achieving the effect of water blocking and moisture prevention. The water blocking layer 7 acts as a passive water blocking barrier, and the water-absorbing expansion layer 8 expands when it comes into contact with water to actively seal the gap. At the same time, the water guiding channel 903 and the water-absorbing expansion layer 8 work together to drive the repair material to form a closed-loop self-repair system, which conforms to the tiered water blocking concept of modern moisture-proof cables, effectively preventing water trees and improving the durability of the cable.

[0024] In a specific example, the cable core 1 includes several stranded conductors 101. Each conductor 101 has a double-sided insulating water-blocking tape 102 on its outer side, and water-blocking powder is filled in the gaps between the strands of the conductors 101. The conductors 101 are preferably copper wires. The double-sided insulating water-blocking tape 102 is longitudinally wrapped around the outer surface of the conductors 101. Both sides of the double-sided insulating water-blocking tape 102 contain highly absorbent resin, which can ensure that each conductor 101 is independently water-blocking, avoiding single-point failure leading to overall water-blocking failure. By filling the gaps between the strands of the conductors 101 with water-blocking powder, which is a highly absorbent resin, the water-blocking powder expands when it comes into contact with water, and can quickly fill the gaps between the strands of the conductors 101. Together with the double-sided insulating water-blocking tape 102, a dense gel is formed, which physically blocks the channels for moisture to diffuse along the axial direction of the conductors 101, further achieving longitudinal water blocking and moisture prevention.

[0025] In a specific example, the cross-section of conductor 101 is fan-shaped or tile-shaped. By twisting conductors 101 with a fan-shaped or tile-shaped structure, an approximately circular cross-section can be formed through close arrangement during cabling, reducing gaps. Compared to the twisted structure of circular conductors, this significantly reduces the outer diameter of the cable, thereby blocking the channels for moisture penetration.

[0026] In a specific example, the cable core 1 also includes a wrapping shielding layer 103, which wraps around and covers the outer surface of the stranded conductor 101. The cable core shielding layer 2 covers the outer surface of the wrapping shielding layer 103. The wrapping shielding layer 103 is made of metal foil, such as aluminum foil or semi-conductive tape, tightly wrapped around the conductor 101 bundle to form a seamless physical isolation layer. This prevents the extrusion material from entering the gaps in the conductor 101 during the subsequent extrusion of the cable core shielding layer 2, thus avoiding stress concentration points and causing partial discharge or insulation breakdown.

[0027] In a specific example, the outer protective layer 10 includes an outer insulation layer 1001 and a wear-resistant layer 1002. The outer insulation layer 1001 covers the outer surface of the support layer 9, and the wear-resistant layer 1002 covers the outer surface of the outer insulation layer 1001. The outer insulation layer 1001 is made of polyethylene, and the wear-resistant layer 1002 is made of nitrile rubber. The outer protective layer 10 is made by co-extrusion of polyethylene and nitrile rubber. Polyethylene is a typical polymeric insulating material that can effectively isolate the risk of current leakage and protect the internal structure of the cable from corrosion. Nitrile rubber has outstanding wear resistance and can buffer external impacts, preventing the outer insulation layer 1001 from cracking. The co-extrusion of the two allows the molecular chains to interpenetrate in the molten state, forming a physically cross-linked layer and avoiding the risk of delamination.

[0028] In this specific example, both the core shielding layer 2 and the insulating shielding layer 4 are made of semi-conductive shielding material, while the inner insulating layer 3 is made of water-tree resistant cross-linked polyethylene. The core shielding layer 2, the inner insulating layer 3, and the insulating shielding layer 4 are co-extruded as three layers. By simultaneously extruding the three layers and bonding them in a molten state in a single process, a dense interface with molecular-level bonding is formed, resulting in smooth interlayer transitions and preventing electric field distortion and partial discharge. This creates synergistic advantages in electric field homogenization, water tree suppression, and interface reliability, effectively improving the reliability of the cable.

[0029] The above description, in conjunction with specific / preferred embodiments, provides a further detailed explanation of the present invention and should not be construed as limiting the specific implementation of the present invention to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the protection scope of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the scope of protection of the patent application.

Claims

1. A moisture-proof cable, characterized in that: The cable core includes a cable core shielding layer on its outer surface, an inner insulation layer on its outer surface, an insulating shielding layer on its outer surface, a flame-retardant layer on its outer surface, a color-developing coating on its outer surface, a water-blocking layer on its outer surface, a water-absorbing and expanding layer on its outer surface, a support layer on its outer surface, and an outer protective layer on its outer surface. The support layer has several grooves on its outer surface, arranged in a circular array along the axial direction of the cable core. A water-soluble sealing film is provided at the opening of each groove, and the grooves are filled with repair material. A water-guiding channel is provided on the support layer, with one end connected to the outer protective layer and the other end connected to the water-absorbing and expanding layer. An expansion cavity is provided on the inner wall of the support layer, corresponding to the bottom of each groove.

2. The moisture-proof cable as described in claim 1, characterized in that: The cable core includes several stranded conductors, each conductor has a double-sided insulating water-blocking tape on its outer side, and the gaps between the strands of the conductors are filled with water-blocking powder.

3. The moisture-proof cable as described in claim 2, characterized in that: The cross-section of the conductor is fan-shaped or tile-shaped.

4. The moisture-proof cable as described in claim 3, characterized in that: The cable core also includes a wrapping shielding layer, which wraps around the outer surface of the conductor after it is stranded into a core, and the cable core shielding layer covers the outer surface of the wrapping shielding layer.

5. The moisture-proof cable as described in claim 1, characterized in that: The outer protective layer includes an outer insulating layer and a wear-resistant layer. The outer insulating layer covers the outer surface of the support layer, and the wear-resistant layer covers the outer surface of the outer insulating layer.

6. The moisture-proof cable as described in claim 5, characterized in that: The outer insulation layer is made of polyethylene, the wear-resistant layer is made of nitrile rubber, and the outer protective layer is made by double-layer co-extrusion of polyethylene and nitrile rubber.

7. The moisture-proof cable as described in claim 1, characterized in that: The support layer is made of polyurethane rubber extrusion.

8. The moisture-proof cable as described in claim 1, characterized in that: The water-absorbing and swelling layer is made of superabsorbent resin, and the water-blocking layer is made of aluminum-plastic composite tape.

9. The moisture-proof cable as described in claim 1, characterized in that: The color-developing coating is a composite of anhydrous cobalt chloride and water-absorbing resin, coated on the outer surface of the insulating shielding layer.

10. The moisture-proof cable as described in claim 1, characterized in that: The cable core shielding layer and the insulating shielding layer are both made of semi-conductive shielding material, and the inner insulating layer is made of water-tree resistant cross-linked polyethylene. The cable core shielding layer, the inner insulating layer, and the insulating shielding layer are three layers co-extruded.

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