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CN-224217277-U - Fireproof pre-branching cable with metal sheath

CN224217277UCN 224217277 UCN224217277 UCN 224217277UCN-224217277-U

Abstract

The utility model discloses a fireproof pre-branching cable with a metal sheath, which comprises a main cable and at least one branch cable, wherein a fireproof branch joint is arranged at the joint of the main cable and the branch cable, the main cable and the branch cable comprise conductors, 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 joint part, the safety is improved, the sealing failure caused by thermal expansion and cold contraction of the traditional joint is avoided, and the fireproof performance of the joint is ensured to be consistent with that of a cable body.

Inventors

  • XIAO WEIGANG
  • ZHOU PENG

Assignees

  • 成都市金顶电线电缆有限责任公司

Dates

Publication Date
20260508
Application Date
20250516

Claims (10)

  1. 1. A metal sheathed fireproof pre-branched cable, comprising: The cable comprises a main cable (1) and at least one branch cable (2), wherein a fireproof branch joint (3) is arranged at the joint of the main cable (1) and the branch cable (2); The main cable (1) and the branch cable (2) comprise conductors (11), a main insulating layer (12), a metal sheath layer (13), a fireproof layer (14) and an outer sheath (15) which are sequentially arranged from inside to outside; The fireproof branch joint (3) comprises a metal sleeve (31) sleeved outside the connecting part, fireproof sealant (32) is filled in the metal sleeve (31), and two ends of the metal sleeve (31) and the metal sheath layer (13) form a continuous conductive path through welding.
  2. 2. The fireproof pre-branched cable with the metal sheath according to claim 1, wherein the metal sheath layer (13) is formed by wrapping an aluminum or aluminum alloy strip with the thickness of 0.2-0.5mm in a spiral winding or longitudinal lap joint mode, and the lap joint rate is not less than 15%.
  3. 3. The metal sheath fireproof pre-branching cable of claim 1, wherein the fireproof layer (14) is formed by wrapping more than two layers of mica tapes, the thickness of a single layer is 0.1-0.3mm, the wrapping overlapping rate is not lower than 30%, or the fireproof pre-branching cable is formed by extruding ceramic silicon rubber, and the thickness is 1.0-2.0mm.
  4. 4. The metal sheath fireproof pre-branching cable of claim 1, wherein a flame-retardant filling layer (16) is arranged between the conductor (11) and the main insulating layer (12), and the flame-retardant filling layer (16) is made of halogen-free flame-retardant polyolefin material, and the oxygen index is more than or equal to 32%.
  5. 5. The fireproof pre-branching cable with a metal sheath according to claim 1, wherein the metal sleeve (31) is a copper or galvanized steel pipe fitting with a wall thickness of 1.0-2.0mm, the inner diameter of the copper or galvanized steel pipe fitting is 5-10mm larger than the outer diameter of the cable at the joint, and the length of the copper or galvanized steel pipe fitting is not smaller than 3 times the diameter of the joint.
  6. 6. The metal-sheathed fireproof pre-branching cable of claim 1, wherein the fireproof sealant (32) is an intumescent fireproof sealant, the expansion coefficient is more than or equal to 5, the fireproof time is more than or equal to 90min, and the withstand temperature is more than or equal to 1000 ℃.
  7. 7. The fireproof pre-branched cable with the metal sheath according to claim 1, wherein the outer sheath (15) is made of halogen-free low-smoke flame-retardant polyolefin material, the surface of the outer sheath is provided with a concave-convex corrugated structure, the corrugated depth is 0.5-1.5mm, and the pitch is 5-10mm.
  8. 8. The metal sheath fireproof pre-branching cable of claim 1, wherein a shielding layer (17) is arranged between the metal sheath layer (13) and the fireproof layer (14), and the shielding layer (17) is formed by braiding tinned copper wires, and the braiding density is more than or equal to 85%.
  9. 9. The metal sheath fireproof pre-branching cable according to claim 1, wherein a cold press welding process is adopted at the joint of the conductor of the branch cable (2) and the main cable (1), a ceramic fireproof adhesive tape (33) is wrapped outside the welding part, and the thickness of the ceramic fireproof adhesive tape (33) is 0.5-1.0mm.
  10. 10. The metal sheath fireproof pre-branching cable of claim 1, wherein the outer surface of the outer sheath (15) is coated with a fireproof coating layer (18), the thickness of the fireproof coating layer (18) is 0.3-0.8mm, and the fireproof pre-branching cable is formed by compounding nano magnesium hydroxide and silicone resin.

Description

Fireproof pre-branching cable with metal sheath Technical Field The utility model relates to the technical field of cables, in particular to a fireproof pre-branched cable with a metal sheath. Background The pre-branched cable is widely applied to a building power distribution system due to the characteristics of flexible wiring and convenient construction. However, the conventional pre-branch cable has the following problems in terms of fire resistance, joint reliability and structural stability: 1. The conventional cable is wrapped by a single flame-retardant sheath or a common mica tape, has short fire-resistant time (usually less than 60 minutes), is easy to carbonize and fail at high temperature, and cannot meet the strict fire-resistant requirements of scenes such as high-rise buildings, subways and the like. 2. The joint structure is weak, the branch joint is usually cast and sealed by a heat-shrinkable sleeve or resin, and is easy to shrink, crack or melt at high temperature, so that the joint becomes a fireproof weak point, and the conductive continuity of the metal sheath is difficult to ensure. 3. The cable has poor mechanical strength and shielding performance, insufficient extrusion resistance and impact resistance, is easy to be damaged by construction, and is easy to be interfered by the outside when lacking an effective electromagnetic shielding layer. 4. The smoke toxicity harm is that the common polyvinyl chloride (PVC) sheath releases toxic halogen gas when burning, and does not meet the requirement of modern buildings on low smoke and no halogen. Disclosure of utility model In order to overcome the defects of the prior art, one of the purposes of the utility model is to provide a fireproof pre-branched cable with a metal sheath. The fireproof pre-branching cable with the metal sheath comprises a main cable and at least one branch cable, wherein a fireproof branch joint is arranged at the joint of the main cable and the branch cable, the main cable and the branch cable comprise conductors, 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, fireproof sealant is filled in the metal sleeve, and continuous conductive paths are formed by welding two ends of the metal sleeve and the metal sheath layer. Further, the metal sheath layer is formed by coating aluminum or aluminum alloy strips with the thickness of 0.2-0.5mm in a spiral winding or longitudinal lap joint mode, and the lap joint rate is not less than 15%. Further, the fireproof layer is formed by wrapping more than two layers of mica tapes, the thickness of a single layer is 0.1-0.3mm, the wrapping overlapping rate is not lower than 30%, or the fireproof layer is formed by extruding ceramic silicon rubber, and the thickness is 1.0-2.0mm. Further, a flame-retardant filling layer is arranged between the conductor and the main insulating layer, the flame-retardant filling layer is made of halogen-free flame-retardant polyolefin material, and the oxygen index is more than or equal to 32%. Furthermore, the metal sleeve adopts a copper or galvanized steel pipe fitting with the wall thickness of 1.0-2.0mm, the inner diameter of the metal sleeve is 5-10mm larger than the outer diameter of the cable at the joint, and the length of the metal sleeve is not smaller than 3 times of the diameter of the joint. Further, the fireproof sealant is an expansion type fireproof sealant, the expansion coefficient is more than or equal to 5, the fireproof time is more than or equal to 90min, and the tolerant temperature is more than or equal to 1000 ℃. Furthermore, the outer sheath is made of halogen-free low-smoke flame-retardant polyolefin material, the surface of the outer sheath is provided with a concave-convex corrugated structure, the corrugated depth is 0.5-1.5mm, and the pitch is 5-10mm. Further, a shielding layer is arranged between the metal sheath layer and the fireproof layer, the shielding layer is formed by weaving tinned copper wires, and the weaving density is more than or equal to 85%. Furthermore, the cold-press welding process is adopted at the connection part of the conductors of the branch cable and the main cable, and the ceramic fireproof adhesive tape is wrapped outside the welding part, and the thickness of the ceramic fireproof adhesive tape is 0.5-1.0mm. Further, the outer surface of the outer sheath is coated with a fireproof coating layer, the thickness of the fireproof coating layer is 0.3-0.8mm, and the fireproof coating layer is formed by compounding nano magnesium hydroxide and silicone resin. Compared with the prior art, the utility model has the beneficial effects that: The utility model obviously improves the comprehensive performance of the cable through the cooperative design of the metal sheath, the layered fireproof and the joint reinforcement,