Flame-retardant B1-level fire-resistant composite shielding cable

Abstract

The utility model relates to the technical field of wires and cables, in particular to a flame-retardant B1-level fire-resistant composite shielding cable, which comprises a plurality of oxygen-free copper stranded wire cores. The flame-retardant filling layer is filled among the plurality of oxygen-free copper stranded wire cores and is wrapped by the wrapping layer to form a circular cable core; the composite shielding layer coats the outer side surface of the cable core; and the outer sheath is extruded on the outer side surface of the composite shielding layer. Each oxygen-free copper stranded wire core comprises a conductor which is formed by mutually stranding a plurality of strands of wires and has a circular cross section, the conductor is coated with an insulation shielding protection layer, and a conductive filling layer is filled between the conductor and the insulation shielding protection layer and is used for filling gaps generated on the surface of the conductor and between the conductor and the insulation shielding protection layer. Through the design of the utility model, the electric field on the outer surface of the conductor can be homogenized, the partial discharge of the conductor and the insulation caused by the unsmooth surface of the conductor and the air gap generated by the twisting of the wire core can be avoided, and the voltage-resistant and torsion-resistant performance of the cable can be provided.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, and particularly relates to a flame-retardant B1-level fire-resistant composite shielded cable. Background Art

[0002] The fire-resistant composite shielded cable is one of the most commonly used wires and cables, which combines fire-resistant performance and shielding function to meet the power or signal transmission requirements in various civil and special environments. It is widely used in various fields such as industry, agriculture, transportation, construction, medical treatment, electronics, and daily life. Especially in modern industrial control, subway, medical treatment and other fields, it is required that the shielded control cable can resist electromagnetic interference and electrostatic interference, ensure the accuracy and stability of signal transmission, and at the same time have high temperature resistance and fire protection characteristics, and can withstand a certain amount of mechanical pressure and external force. For example, under the premise of typical electrical equipment mobile control applications, such as the shielded control cables used in industrial robots, medical equipment, express transportation sorting, pipeline maintenance, mines, road transportation equipment, etc., affected by the actions of the equipment, the cables will frequently bend and twist. After multiple bends and twists, the conductor and the insulating layer of the cable will be disengaged from each other to form gaps, resulting in partial discharge, and even there is a hidden danger of insulation breakdown. Summary of the Utility Model

[0003] In view of the technical problems existing in the flame-retardant B1-level fire-resistant composite shielded cable in the prior art, the first aspect of the utility model provides a flame-retardant B1-level fire-resistant composite shielded cable, including:

[0004] Multiple oxygen-free copper stranded cores, arranged tangentially to each other in pairs;

[0005] A flame-retardant filling layer, filled in the slits formed by the multiple oxygen-free copper stranded cores and wrapped and fixed by a wrapping layer, so that the multiple oxygen-free copper stranded cores and the filled flame-retardant filling layer form a round cable core;

[0006] A composite shielding layer, covering the outer side of the cable core;

[0007] An outer sheath, made of polyolefin sheath material, extruded on the outer side of the composite shielding layer;

[0008] Wherein, the oxygen-free copper stranded core includes a conductor formed by twisting a number of strands of wires into a circular cross-section, an insulating shielding protection layer is covered on the outer side of the conductor, and a conductive filling layer is filled between the conductor and the insulating shielding protection layer for filling the gaps generated on the surface of the conductor itself and between the conductor and the insulating shielding protection layer.

[0009] As an alternative embodiment, the conductive filling layer is a conductive epoxy resin adhesive layer, which is combined between the surface of the conductor and the insulating shielding protective layer, and the proportion of conductive particles filled in the conductive epoxy resin adhesive layer is 45-55%.

[0010] As an alternative embodiment, the filling thickness of the conductive epoxy resin adhesive layer is 0.4-0.8 mm.

[0011] As an alternative embodiment, the conductive particles of the conductive filling layer are micron-sized conductive particles, and the micron-sized conductive particles include at least one of nickel particles, copper particles, and conductive graphite particles, with an average particle size of 50-150 μm.

[0012] As an alternative embodiment, the flame-retardant filling layer includes a mineral oxygen-isolating filling layer.

[0013] As an alternative embodiment, the wrapping layer includes a phlogopite tape wrapping layer, with a wrapping overlap rate greater than 50% and the number of wrapping layers being two.

[0014] As an alternative embodiment, the composite shielding layer is composed of a copper tape wrapping shielding layer and a copper wire braided shielding layer. The copper wire braided shielding layer is coated on the outside of the copper tape wrapping shielding layer, and the overall thickness of the composite shielding layer is 2-2.5 mm.

[0015] As an alternative embodiment, the wrapping overlap rate of the copper tape wrapping shielding layer is greater than 25%.

[0016] As an alternative embodiment, the braiding density of the copper wire braided shielding layer is greater than 90%, and the braiding wire diameter is greater than 0.1 mm.

[0017] As an alternative embodiment, the insulating shielding protective layer includes a conductor shielding layer, an insulating layer, and an insulating shielding layer sequentially coated from the inside out.

[0018] Compared with the prior art, the significant advantages of the flame-retardant B1-level fire-resistant composite shielding cable proposed by the present utility model are as follows:

[0019] 1. By filling a conductive filling layer between the conductor and the insulating shielding protective layer, on the one hand, the conductive epoxy resin adhesive layer makes the conductor and the insulating shielding protective layer integrated. And through the high-density conductive particles filled therein, the outer surface electric field of the conductor is made uniform by the conductive filling layer, avoiding partial discharge between the conductor and the insulation caused by the uneven surface of the conductor and the air gaps generated by the stranding of the wire cores.

[0020] 2. During the bending and twisting of the cable, uneven extrusion forces will be generated between the conductor and the insulating shield protection layer. The insulating shield protection layer will become non-circular, resulting in irregular spacing between the conductor and the insulating shield protection layer. Under the action of the extrusion force, the conductive filling layer can play a buffering and anti-twisting role, avoiding partial discharge caused by the generation of gaps due to bending and twisting. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in each figure may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the present invention will be described by way of example and with reference to the drawings.

[0022] Figure 1 is a schematic structural diagram of the flame-retardant B1-level fire-resistant composite shielded cable shown in the present invention.

[0023] Figure 2 is a schematic structural diagram of the oxygen-free copper stranded wire core 10 in the flame-retardant B1-level fire-resistant composite shielded cable shown in the present invention.

[0024] The definitions of the various reference numerals in the figures are as follows:

[0025] 10. Oxygen-free copper stranded wire core; 11. Conductor; 12. Conductive filling layer; 13. Conductor shield layer; 14. Insulating layer; 15. Insulating shield layer; 20. Filling layer; 30. Wrapping layer; 40. Composite shield layer; 50. Outer sheath. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To better understand the technical content of the present invention, specific embodiments are hereby given and described in conjunction with the accompanying drawings as follows.

[0027] Combined with Figure 1 - Figure 2 shown, the flame-retardant B1-level fire-resistant composite shielded cable of the embodiment of the present invention includes an oxygen-free copper stranded wire core 10, a flame-retardant filling layer 20, a wrapping layer 30, a composite shield layer 40, and an outer sheath 50.

[0028] Multiple oxygen-free copper stranded wire cores 10 are arranged tangentially to each other in pairs. The flame-retardant filling layer 20 is filled in the slits formed by the multiple oxygen-free copper stranded wire cores 10 and is wrapped and fixed by the wrapping layer 30 to form a circular cross-section. The composite shield layer 40 is coated on the outer side of the wrapping layer 30 to play an electromagnetic shielding role. The outer sheath 50 is made of polyolefin sheath material and is extruded on the outer side of the composite shield layer.

[0029] Combined with Figure 2 shown, the oxygen-free copper stranded wire core 10 includes a conductor 11 formed by twisting a number of wires into a circular cross-section, and an insulating shield protection layer is coated on the outer side of the conductor 11.

[0030] In an embodiment of the present utility model, a conductive filling layer 12 is filled between the conductor 11 and the insulating shielding protection layer, which is used to fill the gaps generated on the surface of the conductor itself and between the conductor 11 and the insulating shielding protection layer.

[0031] Combined with the figure, the flame-retardant filling layer 20 is filled in the slits formed by multiple oxygen-free copper stranded cores 10 and is wrapped and fixed by the wrapping layer 30, so that the multiple oxygen-free copper stranded cores and the filled flame-retardant filling layer form a round cable core.

[0032] In the figure, taking the example of four oxygen-free copper stranded cores 10 being twisted together with the flame-retardant filling layer 20, the wrapping layer 30 made of polyurethane layer is wrapped and rolled into a cable core.

[0033] As an optional implementation manner, the conductive filling layer 12 is a conductive epoxy resin glue layer, which is combined between the surface of the conductor 11 and the insulating shielding protection layer, and the proportion of the conductive particles filled in the conductive epoxy resin glue layer is 45 - 55%.

[0034] As an optional implementation manner, the filling thickness of the conductive epoxy resin glue layer is 0.4 - 0.8 mm.

[0035] As an optional implementation manner, the conductive particles of the conductive filling layer 12 are micron-level conductive particles, and the micron-level conductive particles include at least one of nickel particles, copper particles, and conductive graphite particles, with an average particle size of 50 - 150 μm.

[0036] Thus, on the one hand, through the filling of high-density conductive particles, the filling rate and conductivity of the conductive filling layer 12 are improved; on the other hand, through the design of the thin conductive filling layer 12, the uniformity and flatness of the filling are ensured, the homogenization of the external surface electric field is realized, and the risk of partial discharge between the conductor and the insulation caused by the uneven surface of the conductor and the air gaps generated by the stranding of the wire cores is reduced.

[0037] At the same time, based on the bonding force of the conductive epoxy resin glue layer, a tight bond is formed between the conductor 11 and the insulating shielding protection layer, and it plays a role in gap filling, providing buffering and anti-torsion between the two, improving the bending and torsion bearing capacity of the cable, and reducing the occurrence of partial discharge due to the gaps generated by bending and torsion when the cable is repeatedly / frequently rotated and moved by equipment.

[0038] In an optional embodiment, the aforementioned filled conductive particles are selected as a mixture of conductive graphite and other particles. By utilizing the lubricity of the conductive graphite, the friction between the insulating shielding protection layer and the conductor is reduced during the bending and torsion of the cable.

[0039] Combined Figure 2As shown, the insulating shield protection layer includes a conductor shield layer 13, an insulating layer 14, and an insulating shield layer 15 that are sequentially coated from the inside out. The conductor shield layer 13, the insulating layer 14, and the insulating shield layer 15 are co-extruded and simultaneously extruded, effectively avoiding the process gaps caused by separate extrusion.

[0040] In an alternative embodiment, both the conductor shield layer 13 and the insulating shield layer 15 are made of semi-conductive polyolefin material, and the insulating layer 14 is made of cross-linked polyethylene material.

[0041] Combined with Figure 1 As shown, the flame-retardant filling layer 20 includes a mineral oxygen-barrier filling layer. Preferably, the mineral oxygen-barrier filling layer uses magnesium hydroxide. When the cable is exposed to an open flame, magnesium hydroxide can release a large amount of crystal water, which can reduce the flame temperature. At the same time, magnesium oxide generated by the decomposition of magnesium hydroxide is a good refractory material, improving the flame-retardant performance of the cable.

[0042] Furthermore, the wrapping layer 30 includes a mica tape wrapping layer with a wrapping overlap rate greater than 50% and two wrapping layers. The mica tape has a good flame-retardant effect, further improving the overall flame-retardancy of the cable.

[0043] Combined with Figure 1 As shown, the composite shield layer 40 is composed of a copper tape wrapping shield layer and a copper wire braided shield layer. The copper wire braided shield layer is coated on the outside of the copper tape wrapping shield layer. The wrapping overlap rate of the copper tape wrapping shield layer is greater than 25%, the braiding density of the copper wire braided shield layer is greater than 90%, and the braiding wire diameter is greater than or equal to 0.1 mm. The two-layer shielding can effectively improve the overall electromagnetic interference resistance performance of the cable.

[0044] Furthermore, the outer sheath 50 is formed by extrusion of a halogen-free low-smoke flame-retardant polyolefin sheath material. It has the advantages of good flame-retardancy, low smoke emission, and non-toxicity when burning, reducing the smoke emission when the cable is burned by an open flame.

[0045] In this way, by setting the wrapping layer 30 of mica tape, the mineral oxygen-barrier filling layer, and the halogen-free low-smoke flame-retardant polyolefin outer sheath, the overall flame-retardant performance of the cable is improved, enabling the cable to meet the B1-level flame-retardant requirements.

[0046] Although the present utility model has been disclosed above with preferred embodiments, it is not intended to limit the present utility model. Those with ordinary knowledge in the technical field to which the present utility model belongs can make various modifications and refinements without departing from the spirit and scope of the present utility model. Therefore, the protection scope of the present utility model shall be determined by the scope defined in the claims.

Claims

1. A flame retardant B1 grade fire resistant composite shielded cable, characterized in that: include: A plurality of oxygen-free copper twisted wire cores (10), arranged tangentially in pairs; The flame retardant filling layer (20) is filled in the slit formed by the plurality of oxygen-free copper stranded wire cores (10) and is wrapped and solidified by the wrapping layer (30), so that the plurality of oxygen-free copper stranded wire cores (10) and the filled flame retardant filling layer (20) form a round cable core; A composite shielding layer (40) covering the outer side of the cable core; An outer sheath (50) made of a polyolefin sheath material and extruded onto the outer side of the composite shielding layer (40); The oxygen-free copper stranded wire core (10) comprises a conductor (11) formed by twisting a plurality of wire strands into a circular cross-section, the outer side of the conductor (11) is coated with an insulating shielding protective layer, and a conductive filling layer (12) is filled between the conductor (11) and the insulating shielding protective layer to fill the gap between the surface of the conductor (11) itself and between the conductor and the insulating shielding protective layer.

2. The flame-retardant B1 grade fire-resistant composite shielded cable according to claim 1, characterized in that: The flame retardant filling layer (20) comprises a mineral oxygen-isolating filling layer.

3. The flame-retardant B1 grade fire-resistant composite shielded cable according to claim 1, characterized in that: The wrapping layer (30) comprises a phlogopite tape wrapping layer, the wrapping overlap rate is greater than 50%, and the number of wrapping layers is two.

4. The flame-retardant B1 grade fire-resistant composite shielded cable according to claim 1, characterized in that: The composite shielding layer (40) is composed of a copper tape wrapped shielding layer and a copper wire braided shielding layer, the copper wire braided shielding layer is coated on the outside of the copper tape wrapped shielding layer, and the overall thickness of the composite shielding layer is 2-2.5 mm.

5. The flame-retardant B1 grade fire-resistant composite shielded cable according to claim 4, characterized in that: The wrapping overlap rate of the copper tape wrapped shielding layer is greater than 25%.

6. The flame-retardant B1 grade fire-resistant composite shielded cable according to claim 4, characterized in that: The braiding density of the copper wire braided shielding layer is greater than 90%, and the braiding wire diameter is greater than or equal to 0.1 mm.

7. The flame-retardant B1-class fire-resistant composite shielded cable according to claim 1, characterized in that: The insulating shielding protective layer comprises a conductor shielding layer (13), an insulating layer (14) and an insulating shielding layer (15) which are sequentially coated from the inside to the outside.

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