Metal sheath fireproof pre-branched cable

Abstract

The utility model discloses a fireproof pre-branch cable with a metal sheath, which comprises a main cable and at least one branch cable, and a fireproof branch joint is arranged at the joint of the main cable and the branch cable. Each of the main cable and the branch cable comprises a conductor, a main insulating layer, a metal sheath layer, a fireproof layer and an outer sheath which are sequentially arranged from inside to outside; the fireproof branch joint comprises a metal sleeve sleeved outside a connecting part, so that the safety is improved, the sealing failure caused by thermal expansion and cold contraction of a traditional joint is avoided, and the fire resistance of the joint is ensured to be consistent with that of the cable body.

Description

Technical Field

[0001] This utility model relates to the field of cable technology, and in particular to a metal-sheathed fireproof pre-branched cable. Background Technology

[0002] Pre-branched cables are widely used in building power distribution systems due to their flexible wiring and convenient installation. However, traditional pre-branched cables have the following problems in terms of fire resistance, joint reliability, and structural stability:

[0003] 1. Insufficient fire resistance: Conventional cables mostly use a single flame-retardant sheath or ordinary mica tape wrapping, which has a short fire resistance time (usually less than 60 minutes) and is prone to carbonization failure at high temperatures, failing to meet the strict fire protection requirements of high-rise buildings, subways and other scenarios.

[0004] 2. Weak joint structure: Branch joints often use heat shrink tubing or resin casting for sealing, which is prone to shrinkage, cracking or melting at high temperatures, making the joint a weak point in fire protection, and the conductivity continuity of the metal sheath is difficult to guarantee.

[0005] 3. Poor mechanical strength and shielding performance: Non-metallic sheathed cables have insufficient resistance to compression and impact, and are easily damaged during construction; when lacking an effective electromagnetic shielding layer, they are easily affected by external interference.

[0006] 4. Hazards of smoke and toxicity: Ordinary polyvinyl chloride (PVC) sheaths release toxic halogen gases when burned, which does not meet the requirements of modern buildings for low smoke and halogen-free materials. Utility Model Content

[0007] In order to overcome the shortcomings of the existing technology, one of the objectives of this utility model is to provide a metal-sheathed fireproof pre-branched cable.

[0008] One of the objectives of this utility model is achieved by the following technical solution: a metal-sheathed fireproof pre-branched cable, comprising: a main cable and at least one branch cable, wherein a fireproof branch joint is provided at the connection between the main cable and the branch cable; both the main cable and the branch cable comprise, from the inside out, a conductor, a main insulation layer, a metal sheath layer, a fireproof layer, and an outer sheath; the fireproof branch joint comprises a metal sleeve fitted over the outside of the connection part, the metal sleeve being filled with fireproof sealant, and the two ends of the metal sleeve being welded to the metal sheath layer to form a continuous conductive path.

[0009] Furthermore, the metal sheath layer is made of aluminum or aluminum alloy strip with a thickness of 0.2-0.5mm, which is formed by spiral winding or longitudinal overlapping, with an overlap rate of not less than 15%.

[0010] Furthermore, the fireproof layer is composed of two or more layers of mica tape wrapped around it, with a single layer thickness of 0.1-0.3mm and a wrapping overlap rate of not less than 30%; or it is formed by extrusion of ceramicized silicone rubber with a thickness of 1.0-2.0mm.

[0011] Furthermore, a flame-retardant filler layer is provided between the conductor and the main insulation layer. The flame-retardant filler layer is made of halogen-free flame-retardant polyolefin material with an oxygen index ≥32%.

[0012] Furthermore, the metal sleeve is made of copper or galvanized steel with a wall thickness of 1.0-2.0mm, and its inner diameter is 5-10mm larger than the outer diameter of the cable at the connection, and its length is not less than 3 times the diameter of the connection.

[0013] Furthermore, the fire-retardant sealant is an intumescent fire-retardant sealant with an expansion coefficient ≥5, a fire resistance time ≥90min, and a temperature resistance ≥1000℃.

[0014] Furthermore, the outer sheath is made of halogen-free, low-smoke, flame-retardant polyolefin material, with a corrugated surface having a corrugation depth of 0.5-1.5 mm and a pitch of 5-10 mm.

[0015] Furthermore, a shielding layer is provided between the metal sheath layer and the fireproof layer. The shielding layer is made of tin-plated copper wire braided with a braiding density of ≥85%.

[0016] Furthermore, the conductor connection between the branch cable and the main cable is achieved using a cold-press welding process, and the welded area is wrapped with ceramicized fireproof tape with a thickness of 0.5-1.0 mm.

[0017] Furthermore, the outer surface of the outer sheath is coated with a fire-retardant coating layer, the thickness of which is 0.3-0.8 mm, and is composed of nano-magnesium hydroxide and silicone resin.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] This utility model significantly improves the overall performance of the cable through a synergistic design of "metal sheath + layered fireproofing + joint reinforcement," specifically manifested in:

[0020] 1. Multi-layer composite fire protection system

[0021] Metal sheath layer (aluminum / aluminum alloy): forms a physical fire barrier at high temperatures, slowing the spread of flames, and at the same time achieves continuous conductivity throughout the entire path through welding, improving safety.

[0022] Fireproof layer (mica tape / ceramicized silicone rubber): Mica tape is sintered at high temperature to form a ceramic-like hard shell, and ceramicized silicone rubber forms a dense carbonized layer at temperatures above 1000℃. The dual chemical fireproof mechanism ensures a fire resistance time of ≥90 minutes (far exceeding the GB / T 19216 standard).

[0023] Intumescent fireproof sealant: It expands when heated to fill gaps in joints, isolates oxygen, and inhibits the spread of fire.

[0024] 2. High-reliability branch connector

[0025] Metal sleeve welding: The copper / galvanized steel pipe is welded to the metal sheath to form a continuous path with high mechanical strength and good conductivity, avoiding the sealing failure caused by thermal expansion and contraction of traditional joints.

[0026] Cold-pressed welding + ceramicized tape: The conductor connection adopts a cold-pressing process to reduce heat damage, and the outer ceramicized tape further enhances local fire resistance, ensuring that the fire resistance of the joint is consistent with that of the cable body.

[0027] 3. Structural optimization and environmental friendliness

[0028] Shielding layer (tinned copper wire braid): braiding density ≥85%, effectively suppressing electromagnetic interference, suitable for power supply scenarios of precision equipment.

[0029] Flame-retardant filler layer + halogen-free outer sheath: The flame-retardant polyolefin filler layer with an oxygen index ≥32% delays internal combustion, and the halogen-free low-smoke outer sheath reduces the release of toxic gases, in compliance with GB / T 19666 standard.

[0030] Corrugated outer sheath design: increases heat dissipation surface area, reduces temperature rise, and improves bending resistance and ease of construction.

[0031] 4. Economic efficiency and long lifespan

[0032] The combined protection of the metal sheath and fireproof layer reduces the frequency of cable replacement. Materials such as ceramicized silicone rubber have excellent aging resistance and are suitable for harsh environments such as humidity and corrosion.

[0033] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0034] Figure 1 This is a cross-sectional view of the main cable of the component in this embodiment;

[0035] Figure 2 This is a cross-sectional view of the branch cable of the component in this embodiment;

[0036] Figure 3 This is a cross-sectional view of the fireproof branch joint of the component in this embodiment;

[0037] Figure 4 This is a schematic diagram of the ceramicized fireproof tape structure of the component in this embodiment.

[0038] In the diagram: 1. Main cable; 2. Branch cable; 3. Fireproof branch connector; 11. Conductor; 12. Main insulation layer; 13. Metal sheath layer; 14. Fireproof layer; 15. Outer sheath; 16. Flame-retardant filler layer; 17. Shielding layer; 18. Fireproof coating layer; 31. Metal sleeve; 32. Fireproof sealant; 33. Ceramicized fireproof tape. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0040] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] Please see Figures 1 to 4 The metal-sheathed fire-resistant pre-branched cable of this embodiment includes:

[0043] A main cable 1 and at least one branch cable 2, wherein a fireproof branch joint 3 is provided at the connection between the main cable 1 and the branch cable 2;

[0044] Both the main cable 1 and the branch cable 2 include, from the inside out, a conductor 11, a main insulation layer 12, a metal sheath layer 13, a fireproof layer 14, and an outer sheath 15;

[0045] The fireproof branch connector 3 includes a metal sleeve 31 fitted over the outside of the connection point. The metal sleeve 31 is filled with fireproof sealant 32. The two ends of the metal sleeve 31 are welded to the metal sheath layer 13 to form a continuous conductive path. The metal sheath layer 13 is made of aluminum or aluminum alloy strip with a thickness of 0.2-0.5mm, formed by spiral winding or longitudinal overlapping, with an overlap rate of not less than 15%. The fireproof layer 14 is composed of two or more layers of mica tape wrapped around the surface, with a single layer thickness of 0.1-0.3mm and a wrapping overlap rate of not less than 30%; or it is formed by extrusion of ceramicized silicone rubber with a thickness of 1.0-2.0mm. A flame-retardant filler layer 16 is provided between the conductor 11 and the main insulation layer 12. The flame-retardant filler layer 16 is made of halogen-free flame-retardant polyolefin material with an oxygen index ≥32%. The metal sleeve 31 is made of copper or galvanized steel tubing with a wall thickness of 1.0-2.0mm, and its inner diameter is larger than the outer diameter of the cable at the connection point. The diameter of the connection is 5-10mm larger and the length is not less than 3 times the diameter of the connection. The fireproof sealant 32 is an intumescent fireproof sealant with an expansion coefficient ≥5, a fire resistance time ≥90min, and a temperature resistance ≥1000℃. The outer sheath 15 is made of halogen-free, low-smoke, flame-retardant polyolefin material with a corrugated surface structure. The corrugation depth is 0.5-1.5mm and the pitch is 5-10mm. A shielding layer 17 is provided between the metal sheath layer 13 and the fireproof layer 14. The shielding layer 17 is made of tin-plated copper wire braid with a braiding density ≥85%. The conductor connection between the branch cable 2 and the main cable 1 is made of cold-pressed welding process. The welded part is wrapped with ceramicized fireproof tape 33 with a thickness of 0.5-1.0mm. The outer surface of the outer sheath 15 is coated with a fireproof coating layer 18 with a thickness of 0.3-0.8mm, which is composed of nano-magnesium hydroxide and silicone resin.

[0046] The above embodiments are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and substitutions made by those skilled in the art based on this utility model shall fall within the scope of protection claimed by this utility model.

Claims

1. A metal-sheathed fire-resistant pre-branched cable, characterized in that, include: A main cable (1) and at least one branch cable (2), wherein a fireproof branch connector (3) is provided at the connection between the main cable (1) and the branch cable (2); Both the main cable (1) and the branch cable (2) include, from the inside out, a conductor (11), a main insulation layer (12), a metal sheath layer (13), a fireproof layer (14), and an outer sheath (15); The fireproof branch connector (3) includes a metal sleeve (31) sleeved on the outside of the connection part. The metal sleeve (31) is filled with fireproof sealant (32). The two ends of the metal sleeve (31) are welded to the metal sheath layer (13) to form a continuous conductive path.

2. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The metal sheath layer (13) is made of aluminum or aluminum alloy strip with a thickness of 0.2-0.5mm, and is formed by spiral winding or longitudinal overlapping, with an overlap rate of not less than 15%.

3. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The fireproof layer (14) is composed of two or more layers of mica tape wrapped around it, with a single layer thickness of 0.1-0.3mm and a wrapping overlap rate of not less than 30%; or it is formed by extrusion of ceramicized silicone rubber with a thickness of 1.0-2.0mm.

4. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: A flame-retardant filler layer (16) is provided between the conductor (11) and the main insulation layer (12). The flame-retardant filler layer (16) is made of halogen-free flame-retardant polyolefin material with an oxygen index ≥32%.

5. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The metal sleeve (31) is made of copper or galvanized steel with a wall thickness of 1.0-2.0 mm. Its inner diameter is 5-10 mm larger than the outer diameter of the cable at the connection, and its length is not less than 3 times the diameter of the connection.

6. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The fireproof sealant (32) is an intumescent fireproof sealant with an expansion coefficient ≥5, a fire resistance time ≥90min, and a temperature resistance ≥1000℃.

7. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The outer sheath (15) is made of halogen-free, low-smoke, flame-retardant polyolefin material, with a corrugated structure on the surface, a corrugation depth of 0.5-1.5 mm, and a pitch of 5-10 mm.

8. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: A shielding layer (17) is provided between the metal sheath layer (13) and the fireproof layer (14). The shielding layer (17) is made of tin-plated copper wire braided with a braiding density of ≥85%.

9. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The conductor connection between the branch cable (2) and the main cable (1) is achieved by cold pressing welding. The welded part is wrapped with ceramic fireproof tape (33), and the thickness of the ceramic fireproof tape (33) is 0.5-1.0mm.

10. The metal-sheathed fire-resistant pre-branched cable according to claim 1, characterized in that: The outer surface of the outer sheath (15) is coated with a fire-retardant coating layer (18), the thickness of which is 0.3-0.8 mm, and is composed of nano-magnesium hydroxide and silicone resin.

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