Novel 35kV waterproof, rat-proof, ant-proof and ultraviolet-proof B1-level cable for rail transit

Abstract

The utility model discloses a novel 35kV waterproof, rat-proof, ant-proof and ultraviolet-proof B1-level cable for rail transit, which belongs to the technical field of wires and cables and comprises a conductor, the conductor is formed by twisting a plurality of copper cores, water-blocking paste is filled in the conductor, an insulating layer is arranged on the outer side of the conductor, a shielding layer is arranged on the outer side of the insulating layer, and the shielding layer is arranged on the outer side of the insulating layer. A shielding layer is arranged on the outer side of the cable, a glass fiber belt is arranged on the outer side of the shielding layer, an oxygen isolation layer is arranged on the outer side of the glass fiber belt, a sheath layer is arranged on the outer side of the oxygen isolation layer and comprises a corrugated copper sheath and an outer sheath, and the sheath layer is arranged on the outermost layer of the cable. According to the utility model, in the sheath layer, the sheath layer is arranged at the outermost layer of the cable through the corrugated copper sheath and the outer sheath, so that the radial water-blocking performance of the cable can be improved, and external moisture is prevented from permeating into the cable. The sheath layer arranged on the outer layer of the cable can prevent water from entering the cable, and when the sheath layer is damaged, the internal conductor can be prevented from short circuit through the water-blocking paste.

Description

Technical Field

[0001] This utility model relates to a novel 35kV waterproof, rodent-proof, and UV-resistant B1 grade cable for rail transit, belonging to the field of wire and cable technology. Background Technology

[0002] In modern urban rail transit, power cables are a crucial component ensuring the safe and stable operation of trains, with 35kV cables widely used in some high-voltage transmission lines. Due to the limitations of the rail transit environment, cables need to possess a certain degree of resistance to external environmental influences, such as waterproofing, rodent and termite resistance, and UV protection. In environments exposed to high temperatures, humidity, underground, or outdoors, the insulation performance and durability of the cable significantly impact the system's stability and operational safety. Therefore, it is necessary to design a cable capable of withstanding these environmental challenges.

[0003] Currently, cables used in high-voltage transmission lines for rail transit have several defects: Their waterproof performance is not ideal; prolonged exposure to humid environments can lead to moisture penetration, causing a decline in insulation performance and potentially resulting in short circuits; their rodent and ant resistance is insufficient, as the cable materials cannot completely prevent rodent and ant damage; their UV resistance is inadequate, causing materials exposed outdoors to age and crack, shortening their lifespan; and their flame retardant performance is not ideal, with some cables used in rail transit failing to meet the B1 standard, resulting in easily spreading and intense flames when burning. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a new type of 35kV waterproof, rodent-proof, ultraviolet-proof B1 grade cable for rail transit, which solves the problems of waterproof, rodent-proof, ultraviolet-proof, and easy-to-burn high-voltage cables used in rail transit.

[0005] The technical problem to be solved by this utility model is achieved by the following technical solution: a novel 35kV rail transit waterproof, rodent-proof, and UV-resistant B1 grade cable, comprising...

[0006] The conductor is made of multiple copper cores twisted together.

[0007] The conductor is filled with water-blocking paste, and an insulating layer is provided on the outside of the conductor. A shielding layer is provided on the outside of the insulating layer. A fiberglass tape is provided on the outside of the shielding layer. An oxygen barrier layer is provided on the outside of the fiberglass tape. A sheath layer is provided on the outside of the oxygen barrier layer.

[0008] Preferably, the insulating layer is polypropylene, and the polypropylene is fixed to the outside of the conductor by extrusion.

[0009] Preferably, electrical shielding material is also provided on both sides of the insulating layer.

[0010] Preferably, the shielding layer includes a copper wire shielding layer and a copper strip.

[0011] Preferably, the copper wire shielding layer is annealed soft copper wire, which is fixed to the outside of the insulation layer by loose winding.

[0012] Preferably, the copper strip is fixed to the outside of the copper wire shielding layer by winding, and the winding direction of the copper strip is opposite to that of the copper wire shielding layer.

[0013] Preferably, the oxygen barrier layer is a polyolefin, and the polyolefin is fixed to the outside of the shielding layer by extrusion.

[0014] Preferably, the sheath layer includes a corrugated copper sheath and an outer sheath.

[0015] Preferably, the corrugated copper sheath is made by welding copper tubes into a tubular shape and pressing them into a corrugated shape using a mold.

[0016] Preferably, the outer sheath is a B1 grade polyolefin, which is fixed to the outside of the corrugated copper sheath by extrusion.

[0017] The beneficial effects of this utility model are:

[0018] (1) In this invention, the internal conductor is made of multiple copper cores twisted together, and water-blocking grease is twisted inside the conductor. The water-blocking grease can fill the gaps in the conductor and prevent water from penetrating longitudinally along the conductor. In the sheath layer, the sheath layer is set on the outermost layer of the cable through a corrugated copper sheath and an outer sheath, which can improve the radial water-blocking performance of the cable, prevent external water from penetrating into the cable interior, and prevent water from entering from the cable surface. The sheath layer set on the outer layer of the cable can prevent water from entering the cable interior. When the sheath layer is damaged, the internal conductor can also prevent the conductor from short-circuiting through the water-blocking grease.

[0019] (2) According to this utility model, the outermost layer of the cable is a sheath layer, which includes a corrugated copper sheath and an outer sheath. The corrugated copper sheath is made of a metal structure, which provides physical protection against rodents and ants, preventing damage to the cable sheath. The outer sheath, located outside the corrugated copper sheath, incorporates rodent-repellent materials during its manufacturing process, giving it a certain degree of rodent-proof capability. Through the cooperation of the corrugated copper sheath and the outer sheath, the overall rodent-proof function of the cable is guaranteed.

[0020] (3) Through this utility model, the outer sheath of the cable can be manufactured by adding UV stabilizers and anti-aging agents to the raw materials, preventing aging, cracking, or performance degradation even after prolonged exposure to sunlight. Fiberglass tape and an oxygen barrier layer are also provided outside the shielding layer of the cable. The oxygen barrier layer, located outside the shielding layer, has excellent flame-retardant and fire-resistant properties, effectively preventing the spread of flames. The oxygen barrier layer uses highly flame-retardant, low-heat-release polyolefin material to isolate oxygen supply and delay the combustion process. The outer sheath uses B1-grade flame-retardant polyolefin with low dripping characteristics to prevent molten droplets from igniting other equipment in a fire. Regarding the overall flame retardancy of the cable, the multi-layer flame-retardant design ensures that the cable meets B1-grade flame-retardant requirements, guaranteeing a high level of safety in the event of a fire. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model.

[0022] In the diagram: 1-Conductor, 2-Water-blocking paste, 3-Inner layer of insulation, 4-Polypropylene, 5-Outer layer of insulation, 6-Copper wire shielding layer, 7-Copper tape, 8-Fiberglass tape, 9-Oxygen barrier layer, 10-Corrugated copper sheath, 11-Outer sheath. Detailed Implementation

[0023] In order to make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0024] Example 1

[0025] like Figure 1 As shown, a new type of 35kV waterproof, rodent-proof, and UV-resistant B1 grade cable for rail transit is disclosed. The cable has a conductor 1 in the middle, which is composed of multiple copper cores twisted together. The copper cores are circular in shape, with gaps between them. The twisted cable structure meets the environmental requirements for 35kV high-voltage operation and rail transit use.

[0026] The stranded conductor is filled with water-blocking paste 2. The water-blocking paste 2 fills the gaps inside the conductor 1, which can ensure that the conductor has water-blocking function in the longitudinal direction, reduce the impact on the overall performance of the cable in a humid environment, improve the reliability of the cable in harsh environments, and ensure the performance of the cable itself in some underground or humid areas in rail transit.

[0027] An insulating layer is provided on the outside of the conductor, a shielding layer is provided on the outside of the insulating layer, a fiberglass tape 8 is provided on the outside of the shielding layer, an oxygen barrier layer 9 is provided on the outside of the fiberglass tape 8, and a sheath layer is provided on the outside of the oxygen barrier layer 9.

[0028] In this embodiment, the insulating layer is made of polypropylene 4 and is fixed to the outside of conductor 1 by extrusion. (Refer to...) Figure 1 The insulation layer comprises an inner insulation layer 3, a middle insulation layer, and an outer insulation layer 5. All three layers are made of polypropylene 4. The middle insulation layer is also made of polypropylene 4, while the inner and outer insulation layers are made of polypropylene semi-conductive shielding material. The inner, middle, and outer insulation layers are all fixed to the outside of the conductor 1 by extrusion. This extrusion method ensures uniform thickness of the insulation layer, reduces defects, and avoids breakdown caused by localized electric field concentration. The molten material directly wraps around the conductor 1, reducing the gap between the conductor 1 and the insulation layer and improving insulation performance. Furthermore, the extrusion method allows for multi-layer co-extrusion, directly extruding the insulation layer 4 onto the outside of the conductor 1, reducing production steps.

[0029] Reference Figure 1 A shielding layer is provided on the outside of the insulation layer, comprising a copper wire shielding layer 6 and a copper strip 7. The copper wire shielding layer 7 is made of annealed soft copper wire, which is fixed to the outside of the cable layer by loose winding. The copper strip 7 is fixed to the outside of the copper wire shielding layer 6 by winding, and the winding direction of the copper strip 7 is opposite to that of the copper wire shielding layer 6.

[0030] Annealed soft copper wire is copper wire that has undergone annealing treatment, possessing good flexibility and conductivity. Appropriate gaps are maintained between the copper wires as they are wound around the outside of the insulation layer, ensuring conductivity while preventing excessive cable weight or cost. The copper wire shielding layer placed on the outside of the insulation layer mitigates the uneven electric field generated in the cable's working chamber. In the event of a short circuit or overload, the copper wire shielding layer provides an impedance path, quickly guiding the fault current to the grounding device, ensuring the safe operation of the cable.

[0031] The copper strip 7, made of highly conductive copper, is wound around the outside of the copper wire shielding layer 7 in the opposite direction to the winding of the copper wire shielding layer 7. This reverse winding enhances the overall tightness and structural stability of the shielding layer, ensuring its overall stability and preventing the copper wires from loosening due to vibration or external forces. The copper strip 7, in conjunction with the copper wire shielding layer 6, forms a double-shielding structure, further suppressing electromagnetic interference. The copper strip 7 also provides additional mechanical support, enhancing the shielding layer's resistance to pressure and impact.

[0032] When the cable is used in a complex environment, the combination of copper wire shielding layer 6 and copper strip 7 can improve the overall bending and tensile resistance of the cable and ensure its long-term safe operation.

[0033] A fiberglass tape 8 is installed on the outer side of the shielding layer. The fiberglass tape 8 is fixed to the outer side of the shielding layer by wrapping. The fiberglass tape 8 has excellent flame-retardant and fire-resistant properties. Made of high-temperature resistant glass fiber, the fiberglass tape 8 has good flame-retardant and high-temperature resistance properties. The wrapping method ensures uniform and secure coverage. In rail transit, the environment places high demands on the fire resistance of cables. The use of fiberglass tape 8 in the cable ensures that the cable can still perform its functions of transmitting energy and signals under fire conditions. Furthermore, the fiberglass tape 8 improves the operational reliability of the cable in complex environments.

[0034] An oxygen barrier layer 9 is provided on the outside of the fiberglass tape 8. The oxygen barrier layer 9 is made of a highly flame-retardant, low-heat-release polyolefin material, which is fixed to the outside of the fiberglass tape 8 by extrusion. The polyolefin used to make the oxygen barrier layer 9 has undergone special modification treatment, possessing good flame-retardant properties and being less likely to support combustion.

[0035] An outer sheath layer is provided on the outside of the oxygen barrier layer 9, the sheath layer including a corrugated copper sheath 10 and an outer sheath 11. (Refer to...) Figure 1 The corrugated copper sheath 10 is made of copper tubing welded into a tubular shape and then molded into a wavy shape, which improves the overall radial water resistance, flame retardancy, rodent resistance, termite resistance, and bending performance of the cable. The corrugated copper sheath 10 ensures the stability of the cable during long-term operation in humid environments, preventing moisture from entering the cable and causing short circuits or performance degradation. In fire conditions, the corrugated copper sheath 10 does not support combustion and can also act as a heat insulation layer, transferring heat to both ends of the ignition point and preventing the fire from spreading to the internal structure. Using copper as the main material of the corrugated copper sheath 10 ensures that rodents and ants have difficulty chewing through it. The wavy corrugated design improves the flexibility of the corrugated copper sheath 10, facilitating cable installation and bending in confined spaces and enhancing its bending performance.

[0036] The outer sheath 11 is positioned on the outside of the corrugated copper sheath 10. It is made of B1 grade polyolefin and is fixed to the outside of the corrugated copper sheath 10 by extrusion, ensuring that the outer sheath 11 fits tightly against the outside of the corrugated copper sheath 10. During the manufacturing process, UV stabilizers and anti-aging agents are added to the raw materials of the outer sheath 11, which can ensure that it will not age, crack, or degrade in performance even after long-term exposure to sunlight.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of this utility model. All such changes and modifications fall within the scope of protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit, comprising: The conductor is made of multiple copper cores twisted together. Its features are: The conductor is filled with water-blocking paste, and an insulating layer is provided on the outside of the conductor. A shielding layer is provided on the outside of the insulating layer. A fiberglass tape is provided on the outside of the shielding layer. An oxygen barrier layer is provided on the outside of the fiberglass tape. A sheath layer is provided on the outside of the oxygen barrier layer.

2. The novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 1, characterized in that: The insulating layer is made of polypropylene, which is fixed to the outside of the conductor by extrusion.

3. A novel 35kV waterproof, rodent-proof, and UV-resistant B1 grade cable for rail transit according to claim 2, characterized in that: Electrical shielding material is also provided on both sides of the insulating layer.

4. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 1, characterized in that: The shielding layer includes a copper wire shielding layer and a copper strip.

5. A novel 35kV waterproof, rodent-proof, and UV-resistant B1 grade cable for rail transit according to claim 4, characterized in that: The copper wire shielding layer is made of annealed soft copper wire, which is fixed to the outside of the insulation layer by loose winding.

6. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 5, characterized in that: The copper strip is fixed to the outside of the copper wire shielding layer by winding, and the winding direction of the copper strip is opposite to that of the copper wire shielding layer.

7. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 1, characterized in that: The oxygen barrier layer is a polyolefin, which is fixed to the outside of the shielding layer by extrusion.

8. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 1, characterized in that: The sheath layer includes a corrugated copper sheath and an outer sheath.

9. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 8, characterized in that: The corrugated copper sheath is made by welding copper tubes into a tubular shape and pressing them into a corrugated shape using a mold.

10. A novel 35kV waterproof, rodent-proof, and UV-resistant Class B1 cable for rail transit according to claim 8, characterized in that: The outer sheath is made of B1 grade polyolefin and is fixed to the outside of the corrugated copper sheath by extrusion.

Images