Low-temperature anti-cracking novel flexible cable

Abstract

The utility model discloses a low-temperature anti-cracking novel flexible cable, which comprises at least three groups of conductors, each conductor comprises a plurality of twisted flexible round copper wires, the outer wall of each conductor is coated with an insulating layer, the conductors and the insulating layers form a cable core, the outer wall of the cable core is provided with a filling layer, the outer wall of the filling layer is lapped with a lapped layer in an overlapping manner, and the lapped layer is provided with an insulating layer. The outer wall of the wrapping layer is wrapped by a shielding layer formed by weaving copper wires, the outer wall of the shielding layer is wrapped by a lining layer, the outer wall of the lining layer is provided with an armor layer formed by tightly winding low-carbon steel wires, the outer wall of the armor layer is wrapped by a flame-retardant layer, and the outer wall of the flame-retardant layer is wrapped by an outer protective layer. Soft round copper wires are selected as conductors, so that the stability of electric energy transmission of the cable is improved while the overall flexibility of the cable is guaranteed; irradiation crosslinked polyethylene is adopted for insulation, so that the excellent electrical insulation performance, wear resistance, impact resistance, environmental stress cracking resistance and the like of crosslinked polyethylene are reserved, and the defect that during traditional silane steam crosslinking, steam immerses into the insulation to accelerate oxidation of a conductor is overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of low temperature resistance and crack resistance, in particular to a new type of low temperature resistance and crack resistance soft cable. Background Art

[0002] Ordinary cables usually become hard and brittle in low temperature weather or freezing environment, especially when used in environment below -20℃. Any dragging, bending and moving will easily cause cable cracking, affecting the safety of electricity use. However, with the continuous development of science and technology and social economy, various special industries have emerged. A large number of mechanical equipment and instruments need to be used in low temperature environment. In order to ensure that the cables in these equipment can work normally in harsh low temperature environment, it is urgent to design and research a new type of soft cable that is resistant to low temperature and cracking. Utility Model Content

[0003] In view of the above problems, the utility model provides a new type of low-temperature crack-resistant flexible cable to meet the demand for cables in low-temperature harsh environments.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a new type of low-temperature crack-resistant soft cable, comprising a conductor, wherein at least three groups of the conductors are arranged, wherein the conductors include a plurality of twisted soft round copper wires, the outer wall of the conductor is coated with an insulating layer, the conductor and the insulating layer form a cable core, the outer wall of the cable core is provided with a filling layer, the outer wall of the filling layer is overlapped and wrapped with a wrapping layer, the outer wall of the wrapping layer is coated with a shielding layer woven from copper wires, the outer wall of the shielding layer is coated with an inner lining layer, the outer wall of the inner lining layer is provided with an armor layer formed by tightly winding low-carbon steel wires, the outer wall of the armor layer is coated with a flame retardant layer, and the outer wall of the flame retardant layer is coated with an outer sheath.

[0005] Preferably, the conductor is formed by bundle stranding and regular stranding of thin round copper wires drawn from oxygen-free copper rods.

[0006] Preferably, the insulating layer is formed by extrusion of radiation cross-linked polyethylene.

[0007] Preferably, the filling layer is made of acrylic fiber and viscose fiber by high-temperature carbonization.

[0008] Preferably, the shielding layer is woven from fine round copper wires with a weaving density of not less than 80%.

[0009] Preferably, the inner lining layer is formed by extrusion of cold-resistant high-density polyethylene.

[0010] Preferably, the density of the flame retardant layer is not greater than 1.55 g / cm 3 .

[0011] Preferably, the outer sheath is made of PFA plastic extrusion and has a density range of 2.13 to 2.17 g / cm 3 .

[0012] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0013] 1. The soft round copper wire selected as the conductor ensures the overall flexibility of the cable while improving the stability of the cable's power transmission; the irradiated cross-linked polyethylene used for insulation not only retains the excellent electrical insulation, wear resistance, impact resistance, and environmental stress cracking resistance of cross-linked polyethylene, but also avoids the shortcomings of traditional silane vapor cross-linking, such as steam penetrating into the insulation to accelerate conductor oxidation; the carbon fiber reinforced core selected for filling not only has excellent tensile strength, but also has the advantages of thermal expansion and contraction, chemical corrosion resistance, fatigue and aging resistance, etc. At the same time, as a lightweight and high-strength material, it will not significantly increase the overall weight of the cable; the copper wire braided shielding layer not only has excellent anti-interference performance, but also can improve the overall breaking force of the cable to a certain extent.

[0014] 2. The inner lining layer adopts high-density cold-resistant polyethylene, which has good mechanical properties and environmental stress cracking resistance, as well as certain water-blocking and acid-base corrosion resistance. The armor layer composed of low-carbon steel wire can not only fully protect the cable core, but also significantly improve the overall mechanical properties of the cable, meeting the operation requirements of the cable in a low-temperature environment. The cold-resistant, low-smoke, halogen-free polyolefin flame retardant layer not only protects the cable, but also improves the flame retardant and environmental protection performance of the cable, ensuring the service life of the cable and further improving the use scenarios of the cable. The outer sheath formed by PFA plastic extrusion has excellent low-temperature resistance, as well as excellent chemical corrosion resistance and creep resistance, high tensile strength, excellent radiation resistance, non-flammability, high temperature resistance and other advantages, and can be used in harsh outdoor environments for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0016] Figure 2 It is an explosion diagram of the utility model;

[0017] Figure 3 It is a front view schematic diagram of the utility model;

[0018] Figure 4 It is a partial cross-sectional schematic diagram of the utility model.

[0019] Notes in the figure: 1. Conductor; 2. Insulation layer; 3. Filling layer; 4. Wrapping layer; 5. Shielding layer; 6. Lining layer; 7. Armor layer; 8. Flame retardant layer; 9. Outer sheath. DETAILED DESCRIPTION

[0020] The following is a further detailed description of the implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0021] See also Figure 1 and Figure 2 A new type of low-temperature crack-resistant flexible cable, comprising a conductor 1, wherein at least three groups of conductors 1 are provided, wherein the conductor 1 comprises a plurality of soft round copper wires twisted together, wherein the conductor 1 is made of thin round copper wires drawn from oxygen-free copper rods, and is twisted together by bundle twisting and regular twisting, and has a density of 8.89 g / cm 3 ; Linear expansion coefficient is 17×10 -6 (1 / ℃); Resistance temperature coefficient 0.00393 (1 / ℃); DC resistivity at 20℃ ≤≤0.017241Ω·mm 2 / m; the elongation at break after single-wire twisting is ≥5%, and the soft round copper wire selected for the conductor 1 ensures the overall flexibility of the cable while improving the stability of the cable's power transmission.

[0022] See also Figure 1 and Figure 2 The outer wall of the conductor 1 is coated with an insulating layer 2, which is made of radiation cross-linked polyethylene extrusion. The cross-linking method of the insulating layer 2 is upgraded from traditional steam cross-linking to radiation cross-linking, which avoids the disadvantage of steam penetrating into the insulation to accelerate the oxidation of the conductor 1 during traditional steam cross-linking, and also reduces the production process and improves efficiency; the volume resistivity is 1×10 12 Ω·cm, insulation resistance constant 3.67MΩ·km; tensile strength ≥12.5N / mm 2 , elongation at break ≥ 200%; change rate of tensile strength and elongation at break before and after aging (135±3℃, 168h) ≤ ±25%; elongation under load of thermal extension (200±3℃, 20N / cm2) ≤ 175%, permanent elongation after cooling ≤ 15%; thermal shrinkage (130±3℃, 1h) shrinkage ≤ 4%;

[0023] Furthermore, the conductor 1 uses radiation cross-linked polyethylene, which not only retains the excellent electrical insulation, wear resistance, impact resistance, environmental stress cracking resistance and other properties of cross-linked polyethylene, but also avoids the disadvantages of traditional silane vapor cross-linking, such as vapor infiltration into the insulation to accelerate conductor oxidation.

[0024] See also Figure 1 and Figure 2The conductor 1 and the insulating layer 2 form a cable core, and the outer wall of the cable core is provided with a filling layer 3, and the filling layer 3 is made of acrylic fiber and viscose fiber carbonized at high temperature, with a carbon content of more than 90%, low density but high tensile strength and elastic modulus, which can reduce the weight of the product while maintaining strength; in addition, it has good corrosion resistance, fatigue resistance, creep resistance, heat resistance and high temperature resistance, and is easy to process and shape, and is convenient to be processed into a required shape and structure. The outer wall of the filling layer 3 is overlapped and wrapped with a wrapping layer 4, and the wrapping layer 4 is wrapped with a high-strength non-woven fabric;

[0025] Furthermore, the carbon fiber reinforced core selected for the filling layer 3 not only has excellent tensile strength, but also has the advantages of thermal expansion and contraction, chemical corrosion resistance, and resistance to fatigue and aging. At the same time, as a lightweight and high-strength material, it will not significantly increase the overall weight of the cable.

[0026] See also Figure 3 and Figure 4 The outer wall of the wrapping layer 4 is coated with a shielding layer 5 woven from copper wires. The shielding layer 5 is woven from fine round copper wires with a braiding density of not less than 80%. While having excellent anti-interference performance, it can also improve the overall breaking force of the cable to a certain extent and improve the mechanical properties of the cable. The outer wall of the shielding layer 5 is coated with an inner lining layer 6, which is extruded from cold-resistant high-density polyethylene with a density of 0.955-0.978 g / cm 3 ;Tensile strength ≥20.0N / mm 2 , elongation at break ≥ 650%; environmental stress cracking resistance F0 / h ≥ 500; can withstand low-temperature impact brittleness temperature of -76°C, low-temperature elongation at break ≥ 175%; its toughness and cold resistance are good, not only has good mechanical properties and environmental stress cracking resistance, but also is insoluble in any organic solvent, plays a good role in water blocking and acid and alkali corrosion resistance, etc., the outer wall of the inner lining layer 6 is provided with an armor layer 7 formed by tightly winding low-carbon steel wire, so that the armor layer 7 can withstand a large tensile force, suitable for long-distance transmission and use in special environments, and can maintain a good cable structure and conductor shape when subjected to external pressure, thereby ensuring stable electrical performance, improving cable service life and reliability, low-carbon steel wire has high strength and low hardness, which can ensure the softness of the cable; at the same time, the steel wire armor layer can effectively prevent the spread of fire and protect the safe operation of cables and equipment;

[0027] Furthermore, the armor layer 7 composed of low-carbon steel wires can not only fully protect the cable core, but also significantly improve the overall mechanical properties of the cable, meeting the operation requirements of the cable in a low-temperature environment.

[0028] See also Figure 3 and Figure 4The outer wall of the armor layer 7 is coated with a flame retardant layer 8, and the flame retardant layer 8 is a low-smoke halogen-free flame retardant layer and has a density of ≤1.55g / cm 3 ; Oxygen index ≥ 32%; Combustion gas acidity: pH ≥ 4.3, conductivity ≤ 10μs / mm; Smoke density: minimum transmittance ≥ 60%; Halogen gas release during combustion: Hcl and HBr content ≤ 0.5%. It not only protects the cable, but also improves the flame retardant and environmental protection performance of the cable, ensures the service life of the cable, and further improves the use scenario of the cable. The outer wall of the flame retardant layer 8 is covered with an outer sheath 9, which is made of PFA plastic extrusion, and its density range is 2.13~2.17g / cm 3 Its long-term use temperature is -196℃~260℃, and it has excellent low temperature resistance. It also has excellent chemical corrosion resistance and creep resistance, high tensile strength, excellent radiation resistance, non-flammable, high temperature resistance and other advantages. It can be used in harsh outdoor environments for a long time.

[0029] During production of this utility model:

[0030] First, conductor 1 is made by drawing annealed copper monofilament from oxygen-free electrical round copper rod through a copper wire drawing machine, and then twisting it through a wire bundling machine and a wire twisting machine to form conductor 1. The outer side of conductor 1 is extruded through an extruder to form a layer of irradiated cross-linked polyethylene as the insulation layer 2 of the cable core;

[0031] Then, the insulated cores are twisted into a cable, and the gaps between the cores are filled with a carbon fiber reinforced core to form a filling layer 3. At the same time, a layer of high-strength non-woven fabric is wrapped around the outside of the filling layer 3 as a wrapping layer 4, and a shielding layer 5 is woven with copper wire on the outside of the wrapping layer 4.

[0032] Next, a layer of cold-resistant high-density polyethylene material is extruded on the outer side of the shielding layer 5 by an extruder as an inner lining layer 6, and the outer wall of the inner lining layer 6 is tightly wrapped with low-carbon steel wire to form an armor layer 7;

[0033] Finally, a layer of low-smoke halogen-free polyolefin is extruded on the outer wall of the armor layer 7 as the flame retardant layer 8 by an extruder, and a layer of PFA plastic is extruded on the outer wall of the flame retardant layer 8 by an extruder as the outer sheath 9 of the cable, and an identification mark is sprayed on the surface of the outer sheath, and the manufacturing is completed.

[0034] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new type of low temperature crack resistant flexible cable, characterized by: The invention comprises a conductor (1), wherein at least three groups of the conductor (1) are provided, wherein the conductor (1) comprises a plurality of twisted soft round copper wires, wherein the outer walls of the conductors (1) are respectively coated with insulating layers (2), wherein the conductors (1) and the insulating layers (2) form a cable core, wherein the outer wall of the cable core is provided with a filling layer (3), wherein the outer wall of the filling layer (3) is overlapped and wrapped with a wrapping layer (4), wherein the outer wall of the wrapping layer (4) is coated with a shielding layer (5) woven from copper wires, wherein the outer wall of the shielding layer (5) is coated with an inner lining layer (6), wherein the outer wall of the inner lining layer (6) is provided with an armor layer (7) formed by tightly winding low-carbon steel wires, wherein the outer wall of the armor layer (7) is coated with a flame retardant layer (8), and wherein the outer wall of the flame retardant layer (8) is coated with an outer protective layer (9).

2. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The conductor (1) is made of thin round copper wires drawn from oxygen-free copper rods through bundle twisting and regular twisting.

3. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The insulating layer (2) is formed by extrusion of radiation cross-linked polyethylene.

4. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The filling layer (3) is made of acrylic fiber and viscose fiber through high-temperature carbonization.

5. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The shielding layer (5) is woven from fine round copper wires and has a weaving density of not less than 80%.

6. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The inner lining layer (6) is formed by extrusion of cold-resistant high-density polyethylene.

7. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The density of the flame retardant layer (8) is not greater than 1.55 g / cm 3 .

8. A new low-temperature crack-resistant flexible cable according to claim 1, characterized in that: The outer protective layer (9) is made of PFA plastic extrusion and has a density ranging from 2.13 to 2.17 g / cm 3 .

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