1500V halogen-free low-smoke flame-retardant B1-level ratproof waterproof power cable for rail transit

Abstract

The utility model relates to the technical field of wires and cables, in particular to a 1500V halogen-free low-smoke flame-retardant B1-level rat-proof and waterproof power cable for rail transit, which comprises a guide core. The insulating layer is extruded on the outer wall of the guide core; the outer wall of the insulating layer is coated with the waterproof layer; the waterproof layer wraps the outer wall of the waterproof layer; the outer wall of the waterproof layer is coated with the flame-retardant layer; and the outer sheath is extruded on the outer wall of the flame-retardant layer. The insulation structure is designed into two layers, the inner layer is made of the cross-linked polyethylene insulation material, the outer layer is made of the cross-linked polyolefin, the double-layer insulation layer effectively overcomes the non-flame-retardant characteristic of the inner layer insulation, and it is ensured that the overall flame retardance of the cable can meet the B1-level requirement; the waterproof structure adopts the design of the waterproof layer and the comprehensive waterproof layer and is matched with the waterproof factice filling of the conductors, so that the full-waterproof function of longitudinal water resistance and transverse water resistance of the cable is realized, the cable can be soaked in water for a long time, and the safety and reliability of the cable are ensured.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, and more specifically to a 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit. Background Technology

[0002] Currently, apart from some imported DC traction cables, most of the DC traction cables used in rail transit electric traction locomotives are still replaced by AC cables. Conventional AC cables cannot meet the requirements of modern rail transit DC traction systems in terms of insulation design, usage characteristics, environmental adaptability, safety and reliability, and environmental performance. This often leads to problems such as decreased transmission performance, low reliability, high failure rate, low environmental performance, and safety hazards.

[0003] In response to the power supply requirements of DC traction systems in rail transit, there is an urgent need to design and develop a DC traction cable for power transmission that has excellent electrical performance and stable and reliable transmission performance, while also possessing properties such as low smoke and halogen-free, B1-level flame retardancy, waterproofing, and resistance to rodent and ant bites. Utility Model Content

[0004] To address the technical problems existing in current rail transit cables, this utility model proposes a 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit, comprising:

[0005] Core;

[0006] An insulating layer is extruded onto the outer wall of the conductor core;

[0007] A water-blocking layer is wrapped around the outer wall of the insulating layer;

[0008] A waterproof layer is wrapped around the outer wall of the water-blocking layer;

[0009] A flame-retardant layer is wrapped around the outer wall of the waterproof layer;

[0010] The outer sheath is extruded onto the outer wall of the flame-retardant layer;

[0011] A protective layer is extruded onto the outer wall of the outer sheath;

[0012] The conductor core comprises a regularly stranded, multi-layered, rounded conductor structure, with waterproof grease filling the spaces between adjacent conductor structures to form a waterproof grease layer. The insulation layer is a double insulation layer, consisting of an inner insulation layer and an outer insulation layer. The inner insulation layer comprises a cross-linked polyethylene insulation layer, and the outer insulation layer comprises a cross-linked polyolefin insulation layer. The outer sheath comprises a flame-retardant B1 halogen-free polyolefin sheath layer, and the protective layer comprises a nylon sheath layer.

[0013] Preferably, the thickness ratio of the inner insulating layer to the outer insulating layer is 1:3 to 1:4.

[0014] Preferably, the water-blocking layer includes a water-blocking tape wrapping structure, wherein the number of wrapping layers of the water-blocking tape is 2 to 3, and the wrapping overlap rate is 30% ± 5%.

[0015] Preferably, the waterproof layer comprises a double waterproof layer, the inner waterproof layer comprising an aluminum-plastic composite tape layer, and the outer waterproof layer comprising a polyethylene sheath layer.

[0016] Preferably, the aluminum-plastic composite tape layer comprises a longitudinally wrapped aluminum-plastic composite tape, and the polyethylene sheath layer comprises a high-density polyethylene sheath layer.

[0017] Preferably, the thickness of the polyethylene sheath layer is 1.0 mm ± 0.2 mm.

[0018] Preferably, the flame-retardant layer comprises a double flame-retardant layer, the inner flame-retardant layer comprising an oxygen barrier layer, and the outer flame-retardant layer comprising a ceramicized fireproof strip wrapping layer.

[0019] Preferably, the oxygen barrier layer comprises a halogen-free, low-smoke, flame-retardant polyolefin oxygen barrier layer, and the ceramicized fireproof tape wrapping layer comprises a composite fireproof tape wrapping structure, wherein the composite fireproof tape has more than two wrapping layers and the wrapping overlap rate is greater than 30%.

[0020] Preferably, the composite fireproof belt comprises a ceramicized silicone rubber belt and a fiberglass belt that are rolled and laminated together.

[0021] Preferably, the thickness of the nylon sheath layer is less than the thickness of the flame-retardant B1 halogen-free polyolefin sheath layer.

[0022] Compared with existing technologies, the significant advantages of this utility model of a 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit are:

[0023] This utility model discloses a design for a 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit. The cable insulation structure is designed with two layers: the inner layer uses cross-linked polyethylene insulation material, and the outer layer uses cross-linked polyolefin insulation. This double-layer insulation design effectively overcomes the non-flame-retardant characteristics of the inner layer insulation, ensuring that the overall flame retardancy of the cable meets the B1 grade requirement. The waterproof structure adopts a composite design of a water-blocking layer and a comprehensive waterproof layer, combined with water-blocking grease filling the conductor, achieving full water-blocking function in both longitudinal and transverse directions. This ensures that the cable can be used for a long time in water immersion and humid environments, guaranteeing the cable's safety and reliability. A thin nylon sheath is added outside the cable's outer sheath. The protective layer made of this material has ultra-smooth and high hardness characteristics, which can effectively prevent rodents and ants from gnawing. This method is more environmentally friendly than the conventional method of adding pungent rodent repellents to the sheath. Attached Figure Description

[0024] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the structure of a 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit, as shown in this utility model.

[0026] Figure 2 This is a schematic diagram of the cross-sectional structure of a 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit, as shown in this utility model. Detailed Implementation

[0027] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0028] Combination Figure 1 and Figure 2 As shown in the exemplary embodiment of this utility model, the 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit includes, from the inside out, a conductor core 1, an insulation layer 2, a water-blocking layer 3, a waterproof layer 4, a flame-retardant layer 5, an outer sheath 6, and a protective layer 7.

[0029] The conductor core 1 adopts a regular round cross-section structure design, including a regular stranded multi-layer roundly distributed conductor structure 11, combined with the attached... Figure 2 As shown, waterproof grease is filled between adjacent conductor structures 11 (including between adjacent layers of conductor structures 11) to form a waterproof grease layer 12. By adding waterproof grease between the stranded metal wires, the intrusion of water vapor is prevented, especially the transmission of water vapor along the cable axis is avoided.

[0030] Specifically, the multilayer conductor structure 11 is formed by stranding multiple fine copper wires in a regular stranding pattern of 1+6+12+18. During stranding, waterproof grease is applied to the conductor body to fill the gaps between the stranded monofilaments. After the conductor core 1 is covered by the insulation layer 2, the waterproof grease inside the conductor core 1 forms a waterproof grease layer 12 with a specific position and shape.

[0031] Combination Figure 1 , Figure 2 As shown, the insulating layer 2 is extruded onto the outside of the conductor core 1.

[0032] The insulation layer 2 is a double-layer design, consisting of an inner insulation layer 21 and an outer insulation layer 22. The inner insulation layer 21 includes a cross-linked polyethylene insulation layer, which has high electrical insulation performance to ensure the electrical safety of the cable. The outer insulation layer 22 includes a cross-linked polyolefin insulation layer, which has good heat resistance to meet the operating temperature requirements of the cable. It also has good halogen-free, low-smoke flame-retardant properties to effectively overcome the non-flame-retardant nature of the inner insulation layer 21, ensuring that the overall flame retardancy of the cable meets the B1 rating requirement.

[0033] In an optional embodiment, the thickness ratio of the inner insulating layer 21 to the outer insulating layer 22 is 1:3 to 1:4.

[0034] In particular, the thickness ratio of the inner insulation layer 21 to the outer insulation layer 22 is preferably 1:3.5. In this way, by using two different graded insulations, the electric field strength of the cable can be effectively reduced, space charge accumulation can be avoided, and the safety and stability of DC transmission can be guaranteed.

[0035] Combination Figure 1 , Figure 2 As shown, the water-blocking layer 3 covers the outer wall of the insulating layer 2.

[0036] In an optional embodiment, the water-blocking layer 3 includes a water-blocking tape wrapping structure. Specifically, the water-blocking tape is wrapped around the outer wall of the outer insulation layer 22, with 2 to 3 wrapping layers and an overlap rate of 30% ± 5%.

[0037] Therefore, by using water-blocking tape to wrap the cable, the rate of water diffusion inside the cable can be slowed down or prevented. Even if the cable sheath is damaged, water can be effectively prevented from spreading further along the longitudinal direction of the cable, thus protecting the cable's insulation layer 2 and conductor core 1.

[0038] Furthermore, in conjunction with the appendix Figure 1 , Figure 2 As shown, in order to prevent moisture from penetrating into the water-blocking layer 3, a waterproof layer 4 is provided on the outer wall of the water-blocking layer 3.

[0039] In an optional embodiment, the waterproof layer 4 includes a double waterproof layer, the inner waterproof layer including an aluminum-plastic composite tape layer 41, and the outer waterproof layer including a polyethylene sheath layer 42.

[0040] Among them, the aluminum-plastic composite tape layer 41 includes a longitudinally wrapped aluminum-plastic composite tape, and the polyethylene sheath layer 42 includes a high-density polyethylene sheath layer.

[0041] Preferably, in order to prevent the polyethylene sheath layer 42, which is located inside the flame-retardant layer 5, from being burned in a flame environment, the thickness of the polyethylene sheath layer 42 is 1.0 mm ± 0.2 mm.

[0042] Specifically, firstly, the aluminum-plastic composite tape is longitudinally wrapped around the water-blocking layer 3, and then a heating device is used to heat the gaps to bond them together to form an aluminum-plastic composite tape layer 41. At the same time, a layer of high-density polyethylene sheath material is extruded on the surface of the aluminum-plastic composite tape layer 41 to form a polyethylene sheath layer 42, so that the two are integrated.

[0043] Therefore, by combining the impermeability of the aluminum-plastic composite tape with the density of the high-density polyethylene polymer material, excellent water-blocking performance can be achieved, ensuring that the cable maintains good electrical and mechanical properties in various harsh environments. In particular, it can completely prevent water penetration even when the cable is immersed in water for a long time or periodically.

[0044] Combination Figure 1 , Figure 2 In the example shown, the flame retardant layer 5 covers the outer wall of the waterproof layer 4. The flame retardant layer 5 includes a double flame retardant layer. The inner flame retardant layer includes an oxygen barrier layer 51, which is extruded onto the outer wall of the polyethylene sheath layer 42. The outer flame retardant layer includes a ceramicized fireproof tape wrapping layer 52.

[0045] In an optional embodiment, the oxygen barrier layer 51 includes a halogen-free, low-smoke, flame-retardant polyolefin oxygen barrier layer, and the ceramicized fireproof tape wrapping layer 52 includes a composite fireproof tape wrapping structure, wherein the composite fireproof tape has more than two wrapping layers and the wrapping overlap rate is greater than 30%.

[0046] In an optional embodiment, the composite fireproof strip includes a ceramicized silicone rubber strip and a fiberglass strip that are rolled and laminated together.

[0047] Thus, the oxygen index of the halogen-free, low-smoke, flame-retardant polyolefin oxygen barrier layer is as high as 50%, which can play a very good flame-retardant barrier and prevent the waterproof polyethylene inside from being burned.

[0048] Combined with the ceramicized fireproof strip set on the outside of the oxygen barrier layer 51, this material has the characteristics of being non-combustible and high temperature resistant, and can resist flame erosion above 1000℃. It forms a flame-retardant barrier with the flame-retardant oxygen barrier layer, which can ensure that when the two are burned by flames, they form a solid "shell" to effectively prevent the flame from spreading into the inside of the cable.

[0049] Combination Figure 1 , Figure 2 As shown, the outer sheath 6 is extruded onto the outer wall of the ceramicized fireproof strip wrapping layer 52.

[0050] The protective layer 7 is extruded onto the outer wall of the outer sheath 6.

[0051] Optionally, the outer sheath 6 includes a flame-retardant B1 halogen-free polyolefin sheath layer. The flame-retardant B1 halogen-free polyolefin sheath layer has the characteristics of good flame retardancy, low heat release, good shell formation, and UV resistance. It can effectively form the first flame-retardant barrier to ensure that the cable passes the flame-retardant B1 level test, while also ensuring the cable's UV resistance.

[0052] In this design, the protective layer 7 includes a nylon sheath layer. The thickness of the nylon sheath layer is less than that of the flame-retardant B1 halogen-free polyolefin sheath layer. The nylon sheath layer has ultra-smoothness and high hardness. It can effectively prevent rodent and ant bites. Compared with the conventional method of adding pungent rodent repellents to the sheath, which causes the cable to emit an unpleasant odor to achieve rodent and ant prevention, this method is more environmentally friendly and reduces the harm to the human body caused by irritating odors during installation.

[0053] Based on the above embodiments, the design of the 1500V halogen-free, low-smoke, flame-retardant, B1-grade rodent-proof and waterproof power cable for rail transit of this utility model features a double-layer insulation structure. The inner layer uses cross-linked polyethylene insulation material, and the outer layer uses cross-linked polyolefin insulation. The double-layer insulation design effectively overcomes the non-flame-retardant characteristics of the inner layer insulation, ensuring that the overall flame retardancy of the cable meets the B1 grade requirements.

[0054] Its waterproof structure adopts a composite design of water-blocking layer and comprehensive waterproof layer, and at the same time, it is filled with water-blocking grease for conductor, realizing the full water-blocking function of longitudinal and transverse water blocking of the cable, ensuring that the cable can be used for a long time in water immersion and humid environment, and ensuring the safety and reliability of the cable.

[0055] Furthermore, a thin nylon sheath is installed outside the outer sheath of the cable. The protective layer made of this material has the characteristics of being ultra-smooth and having high hardness, which can effectively prevent rodents and ants from gnawing. This method is more environmentally friendly than adding pungent rodent repellents to the conventional sheath design.

[0056] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A 1500V halogen-free low-smoke flame-retardant B1-grade rat-proofing and waterproof power cable for rail transit, characterized in that, It comprises: a core (1); an insulation layer (2) extruded on the outer wall of the core (1); a water-blocking layer (3) coated on the outer wall of the insulation layer (2); a waterproof layer (4) coated on the outer wall of the water-blocking layer (3); a flame-retardant layer (5) coated on the outer wall of the waterproof layer (4); an outer sheath (6) extruded on the outer wall of the flame-retardant layer (5); a protective layer (7) extruded on the outer wall of the outer sheath (6); wherein the core (1) comprises a plurality of regularly twisted and circularly distributed conductor structures (11), and the waterproof ointment layer (12) is formed by filling waterproof ointment between adjacent conductor structures (11); the insulation layer (2) is a double insulation layer composed of an inner insulation layer (21) and an outer insulation layer (22), the inner insulation layer (21) comprises a cross-linked polyethylene insulation layer, and the outer insulation layer (22) comprises a cross-linked polyolefin insulation layer; the outer sheath (6) comprises a flame-retardant B1 halogen-free polyolefin sheath layer, and the protective layer (7) comprises a nylon sheath layer.

2. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 1, characterized in that, The thickness ratio of the inner insulation layer (21) to the outer insulation layer (22) is 1:3-1:

4.

3. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 1, characterized in that, The water-blocking layer (3) comprises a water-blocking tape wrapping structure, the number of wrapping layers of the water-blocking tape is 2-3, and the wrapping coverage rate is 30%±5%.

4. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 1, characterized in that, The waterproof layer (4) comprises a double-layer waterproof layer, the inner layer of the waterproof layer comprises an aluminum-plastic composite tape layer (41), and the outer layer of the waterproof layer comprises a polyethylene sheath layer (42).

5. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 4, characterized in that, The aluminum-plastic composite tape layer (41) comprises a longitudinally wrapped aluminum-plastic composite tape, and the polyethylene sheath layer (42) comprises a high-density polyethylene sheath layer.

6. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 4, characterized in that, The thickness of the polyethylene sheath layer (42) is 1.0 mm±0.2 mm.

7. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 1, characterized in that, The flame-retardant layer (5) comprises a double-layer flame-retardant layer, the inner layer of the flame-retardant layer comprises an oxygen barrier layer (51), and the outer layer of the flame-retardant layer comprises a ceramicized fireproof tape wrapping layer (52).

8. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 7, characterized in that, The oxygen barrier layer (51) comprises a halogen-free low-smoke flame-retardant polyolefin oxygen barrier layer, and the ceramicized fireproof tape wrapping layer (52) comprises a composite fireproof tape wrapping structure, the number of wrapping layers of the composite fireproof tape is greater than two, and the wrapping coverage rate is greater than 30%.

9. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 8, characterized in that, The composite fireproof tape comprises a ceramicized silicone rubber tape and a glass fiber tape that are pressure-bonded together.

10. The 1500V halogen-free low-smoke flame-retardant B1-grade rodent-proof and waterproof power cable for rail transit according to claim 1, characterized in that, The thickness of the nylon sheath layer is less than that of the flame-retardant B1 halogen-free polyolefin sheath layer.

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