Internal shielding railway digital signal cable

Abstract

The utility model discloses an internal shielding railway digital signal cable, which comprises an outer sheath, an armor layer, an inner lining layer, an aluminum sheath shielding layer, an outer heat insulation layer, a cable core wrapping tape and a cable core which are sequentially arranged from outside to inside, each shielding four-wire group comprises an inner heat insulation layer, a copper-aluminum composite shielding layer, an embossed belt and an insulation unit which are sequentially arranged from outside to inside, each insulation unit comprises four insulation single wires which are twisted in different colors, and a discharge wire is arranged between the inner heat insulation layer and the copper-aluminum composite shielding layer. The internal shielding railway digital signal cable provided by the utility model has excellent corrosion resistance, flexibility and electromagnetic shielding performance, can effectively inhibit the passing of electromagnetic waves in an extreme environment of a railway, does not interfere with each other among wire groups, can also prevent the cable from being torn when the cable is extruded by a larger external force or the cable is greatly bent, and improves the service life of the cable. Therefore, normal signal transmission is ensured.

Description

TECHNICAL FIELD

[0001] The utility model belongs to cable technical field, concretely relates to an inner shield railway digital signal cable. BACKGROUND

[0002] With the complication of cable application scene, higher requirements are put forward to the corrosion resistance and flexibility of the cable. In some harsh outdoor environment or industrial environment with chemical corrosion risk, the conventional aluminum sheath is easy to be corroded and damaged, resulting in the decline of the protection function of the cable and affecting the normal use of the cable. In addition, the existing inner shield railway digital signal cable has defects such as poor conductivity and shielding performance of the shielding layer of the shielding four-wire group, which causes major safety hazards to the safe operation of the railway. Therefore, it has important practical significance to develop an inner shield railway digital signal cable with good corrosion resistance, flexibility, conductivity and electromagnetic shielding property. SUMMARY

[0003] In order to solve the technical problems existing in the prior art, the purpose of the utility model is to provide an inner shield railway digital signal cable.

[0004] In order to achieve the above-mentioned purpose and achieve the above-mentioned technical effect, the utility model adopts the following technical scheme:

[0005] An inner shield railway digital signal cable, comprising an outer sheath, an armor layer, an inner liner, an aluminum sheath shielding layer, an outer thermal insulation layer, a cable core wrapping tape and a cable core arranged in sequence from outside to inside, the cable core comprising a plurality of shielding four-wire groups, each shielding four-wire group comprising an inner thermal insulation layer, a copper-aluminum composite shielding layer, an embossed tape and an insulation unit arranged in sequence from outside to inside, the insulation unit comprising four insulated single wires of different colors twisted together, and a leakage conductor is arranged between the inner thermal insulation layer and the copper-aluminum composite shielding layer 3.

[0006] Further, the aluminum sheath shielding layer comprises an aluminum base layer, a corrosion-resistant coating layer and a flexible reinforcing layer, the corrosion-resistant coating layer is coated on the outer surface of the aluminum base layer, and the flexible reinforcing layer is arranged on the inner surface of the aluminum base layer.

[0007] Further, the aluminum base layer is made of aluminum with a purity of not less than 99.5%, and the thickness is 0.5-1.5mm.

[0008] Further, the thickness of the corrosion-resistant coating layer is 20-50μm.

[0009] Further, the thickness of the flexible reinforcing layer is 0.2-0.5mm.

[0010] Further, the cabling twisting pitch of the shielding four-wire group is 35-55 times of the outer diameter of the cable core.

[0011] Further, the thickness of the outer sheath is 1-3mm; the thickness of the inner lining layer is 0.5-1.5mm; the thickness of the outer thermal insulation layer is 0.2-1.0mm; the thickness of the inner thermal insulation layer is 0.1-0.7mm; and the oxygen barrier layer and the flame-retardant layer with the thickness of 0.2-1.0mm is arranged or not arranged between the inner lining layer and the aluminum sheath shielding layer.

[0012] Further, the armored layer is a galvanized steel wire armored layer or a galvanized double steel belt armored layer.

[0013] Further, the conductivity of the copper-aluminum composite shielding layer is not less than 64% IACS.

[0014] Further, the insulated single wire comprises a conductor and isolation and insulation arranged outside the conductor in sequence from inside to outside, and the insulation is a three-layer co-extruded skin-cell-skin physical foaming structure.

[0015] Compared with the prior art, the utility model has the beneficial effects that:

[0016] The utility model discloses an inner shielding railway digital signal cable, has excellent corrosion resistance, flexibility and electromagnetic shielding performance, can effectively inhibit the passing of electromagnetic wave under the railway extreme environment, and the line group also can not interfere with each other, can also avoid the tearing of cable when being extruded by larger external force or the cable being bent greatly, thereby guaranteeing normal signal transmission. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the structural schematic diagram of the utility model;

[0018] Among them, 1, insulated single wire;2, embossed belt;3, copper-aluminum composite shielding layer;4, drainage wire;5, inner thermal insulation layer;6, shielding four line group;7, cable core tape;8, outer thermal insulation layer;9, aluminum sheath shielding layer;10, inner lining layer;11, armored layer;12, outer sheath. DETAILED DESCRIPTION

[0019] The utility model will be described below in detail, so that the advantages and characteristics of the utility model can be more easily understood by the person skilled in the art, so that the protection scope of the utility model is more clearly defined.

[0020] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0021] As Figure 1As shown, an inner shielding railway digital signal cable comprises, from outside to inside, an outer sheath 12, an armor layer 11, an inner lining layer 10, an aluminum sheath shielding layer 9, an outer thermal insulation layer 8, a cable core wrapping 7 and a cable core. The cable core comprises a plurality of shielded four-wire groups 6. Each shielded four-wire group 6 comprises, from outside to inside, an inner thermal insulation layer 5, a copper-aluminum composite shielding layer 3, an embossed tape 2 and an insulation unit. The insulation unit comprises a plurality of insulated single wires 1 of different colors twisted together. A drain wire 4 is arranged between the inner thermal insulation layer 5 and the copper-aluminum composite shielding layer 3, which can ensure that the copper-aluminum composite shielding layer 3 always maintains excellent anti-interference performance after laying and long-term use, and meets the shielding grounding requirements.

[0022] In some embodiments, the insulated single wire 1 comprises a conductor, preferably a copper conductor, and isolation and insulation arranged outside the conductor from inside to outside. The isolation is preferably made of polyolefin material, and the insulation is preferably a three-layer co-extruded skin-cell-skin physical foaming structure, which can improve the cable insulation resistance, reduce the cable transmission loss, and reduce the working capacitance of the cable, thereby greatly improving the safety and reliability of the cable in use.

[0023] The copper-aluminum composite shielding layer 3 is made by stacking the copper layer and the aluminum layer together through explosive compounding, and then performing explosive impact to make the two metal layers into a copper-aluminum composite tape. The copper-aluminum composite shielding layer 3 made in this way has high bonding strength and good mechanical properties, which enables the copper-aluminum composite shielding layer 3 to withstand a large stress without being damaged when subjected to external forces such as stretching and shearing, thereby ensuring the durability of the copper-aluminum composite shielding layer 3 in different application scenarios and adapting to various complex installation and use environments. At the same time, since copper and aluminum both have good electrical conductivity, the electrical conductivity of the copper-aluminum composite shielding layer 3 is not less than 64% IACS (International Annealed Copper Standard), which can effectively conduct current and electromagnetic signals. In applications requiring electromagnetic shielding, high electrical conductivity helps to quickly lead out induced current, thereby better achieving the shielding effect of electromagnetic interference and ensuring the normal operation of electronic devices or systems.

[0024] The aluminum sheath shielding layer 9 comprises an aluminum base layer, a corrosion-resistant coating layer and a flexible reinforcing layer.

[0025] The aluminum base layer is made of aluminum material with a purity of not less than 99.5%, and the thickness is 0.5-1.5mm. The aluminum base layer provides basic mechanical strength and shielding performance for the aluminum sheath shielding layer 9. The preparation method of the aluminum base layer is as follows:

[0026] Aluminum material with a purity of not less than 99.5% is selected, heated to 700-750℃ in a melting furnace for melting, and refined to remove impurities after the aluminum material is completely melted. The refined aluminum liquid is cast into a mold to form an aluminum ingot, and then the aluminum ingot is processed into an aluminum plate with a thickness of 0.5-1.5mm through hot rolling and cold rolling processes.

[0027] A corrosion-resistant coating is coated on the outer surface of the aluminum base layer, and the thickness of the corrosion-resistant coating is 20-50 μm. The corrosion-resistant coating is made of fluorocarbon resin, nano-titanium dioxide and additives. The fluorocarbon resin has excellent weather resistance and chemical corrosion resistance. The nano-titanium dioxide can enhance the ultraviolet resistance and self-cleaning performance of the corrosion-resistant coating. The additives include dispersants, defoamers and the like, which are used to improve the construction performance and stability of the corrosion-resistant coating. The preparation and coating method of the corrosion-resistant coating are as follows:

[0028] According to the mass ratio, 70% of fluorocarbon resin, 20% of nano-titanium dioxide and 10% of additives are mixed, and an appropriate amount of organic solvent is added. The mixture is stirred in a high-speed mixer for 20-40 min to prepare a uniform corrosion-resistant coating;

[0029] The corrosion-resistant coating is uniformly sprayed on the outer surface of the aluminum base layer by using a spray gun, and the thickness of the coating is controlled to be 20-50 μm. The aluminum base layer coated with the corrosion-resistant coating is placed in an oven and baked at 170-180 ℃ for 40-50 min to cure the corrosion-resistant coating to form a corrosion-resistant coating.

[0030] A flexible reinforcing layer is arranged on the inner surface of the aluminum base layer and is woven from aramid fibers. The thickness of the flexible reinforcing layer is 0.2-0.5 mm. The aramid fibers have high strength, high modulus and good flexibility, which can effectively enhance the flexibility and tear resistance of the aluminum sheath shielding layer 9.

[0031] The preparation and arrangement method of the flexible reinforcing layer are as follows:

[0032] High-strength aramid fibers are selected and woven into a tubular flexible reinforcing layer by a weaving machine. The thickness of the flexible reinforcing layer is 0.2-0.5 mm.

[0033] The flexible reinforcing layer is sleeved on the inner surface of the aluminum base layer, and then heat pressing is performed in a hot press. The heat pressing temperature is 110-130 ℃, the pressure is 4-6 MPa, and the pressure holding time is 10-15 min. The flexible reinforcing layer is tightly combined with the aluminum base layer.

[0034] The thickness of the outer sheath 12 is 1-3 mm, and the outer sheath 12 is made of flame-retardant thermoplastic elastomer polyurethane material.

[0035] The thickness of the inner lining layer 10 is 0.5-1.5 mm, and the inner lining layer 10 is made of halogen-free low-smoke flame-retardant polyolefin material.

[0036] An oxygen barrier and flame-retardant layer is arranged or not arranged between the inner lining layer 10 and the aluminum sheath shielding layer 9. The thickness of the oxygen barrier and flame-retardant layer is 0.2-1.0 mm.

[0037] The thickness of the outer thermal insulation layer 8 is 0.2-1.0 mm, and the outer thermal insulation layer 8 is made of polyethylene material.

[0038] The thickness of the cable core wrapping tape 7 is 0.1-0.5mm, and the low-smoke halogen-free flame-retardant wrapping tape is used.

[0039] The thickness of the inner thermal insulation layer 5 is 0.1-0.7mm, and the polyethylene material is used.

[0040] The armored layer 11 is a galvanized steel wire armored layer or a galvanized double steel belt armored layer.

[0041] In the production of the cable, first, the round copper wire is drawn into a copper conductor meeting the technical requirements by using the wire drawing and extrusion series process, and the isolation, inner skin layer, foaming layer and outer skin layer are extruded on the outer surface of the copper conductor at one time, so that the production of the insulated single wire 1 is completed.

[0042] A plurality of insulated single wires 1 of different colors are stranded, and then the embossed tape 2 and the copper-aluminum composite shielding layer 3 are sequentially wrapped outside the stranded insulated single wires, and then the drain wire 4 is arranged outside the copper-aluminum composite shielding layer 3, and then a layer of inner thermal insulation layer 5 is wrapped to form a shielded four-wire group.

[0043] According to the requirements, a plurality of shielded four-wire groups produced are stranded together by using a high-speed cabling machine to form a cable core, and then the cable core wrapping tape 7, the outer thermal insulation layer 8, the aluminum sheath shielding layer 9, the inner lining layer 10, the armored layer 11 and the outer sheath 12 are sequentially wrapped outside the cable core, so that the required inner-shielded railway digital signal cable is produced.

[0044] In order to ensure that the electrical performance indicators of the cable are qualified, in the production process, the tension of all the shielded four-wire groups in the cable core must be consistent, and the setting range of the stranded pitch of the shielded four-wire group to form the cable is 35-55 times the outer diameter of the cable core.

[0045] Embodiment 1

[0046] As shown in Figure 1 An inner-shielded railway digital signal cable includes, from outside to inside, an outer sheath 12, an armored layer 11, an inner lining layer 10, an aluminum sheath shielding layer 9, an outer thermal insulation layer 8, a cable core wrapping tape 7 and a cable core. The cable core includes three shielded four-wire groups 6, each of which includes, from outside to inside, an inner thermal insulation layer 5, a copper-aluminum composite shielding layer 3, an embossed tape 2 and an insulated unit. The insulated unit includes four insulated single wires 1 of different colors stranded together. The inner thermal insulation layer 5 and the copper-aluminum composite shielding layer 3 are provided with a drain wire 4, which can ensure that the copper-aluminum composite shielding layer 3 always maintains excellent anti-interference performance after laying and long-term use, and meets the shielding grounding requirement.

[0047] The insulating single wire 1 comprises a copper conductor and isolation and insulation arranged outside the copper conductor from inside to outside. The isolation is made of polyolefin material, and the insulation is a three-layer co-extruded skin-cell-skin physical foaming structure, which can improve the cable insulation resistance, reduce the cable transmission loss, and reduce the working capacitance of the cable, thereby greatly improving the safety and reliability of the cable.

[0048] The copper-aluminum composite shielding layer 3 is made by stacking the copper layer and the aluminum layer together and then performing explosive impact to make the copper layer and the aluminum layer into a copper-aluminum composite tape. The copper-aluminum composite shielding layer 3 has high bonding strength and good mechanical properties, with a shear strength of 96.5 MPa, a tensile strength of 551 MPa, and an elongation of 17%. This allows the copper-aluminum composite shielding layer 3 to withstand a large stress without being damaged when subjected to external forces such as stretching and shearing, ensuring its durability in different application scenarios and adapting to various complex installation and use environments. At the same time, since copper and aluminum both have good electrical conductivity, the copper-aluminum composite shielding layer 3 has a conductivity of 67% IACS, which can effectively conduct current and electromagnetic signals. In applications requiring electromagnetic shielding, high electrical conductivity helps to quickly lead out induced current, thereby better achieving the shielding effect of electromagnetic interference and ensuring the normal operation of electronic devices or systems.

[0049] The aluminum sheath shielding layer 9 comprises an aluminum base layer, a corrosion-resistant coating, and a flexible reinforcing layer.

[0050] The aluminum base layer is made of aluminum material with a purity of 99.5% and has a thickness of 1.2 mm. The aluminum base layer provides basic mechanical strength and shielding performance for the aluminum sheath shielding layer 9. The preparation method of the aluminum base layer is as follows:

[0051] The aluminum material with a purity of 99.5% is heated to 750°C in a melting furnace for melting. After the aluminum material is completely melted, refining is performed to remove impurities. The refined aluminum liquid is poured into a mold to form an aluminum ingot, which is then processed into an aluminum plate with a thickness of 1.2 mm through hot rolling and cold rolling processes.

[0052] The corrosion-resistant coating is coated on the outer surface of the aluminum base layer, and the thickness of the corrosion-resistant coating is 30 μm. The corrosion-resistant coating is made of fluorocarbon resin, nano-titanium dioxide, and additives. Fluorocarbon resin has excellent weather resistance and chemical corrosion resistance, nano-titanium dioxide can enhance the anti-ultraviolet ability and self-cleaning performance of the corrosion-resistant coating, and additives including dispersants and defoamers are used to improve the construction performance and stability of the corrosion-resistant coating. The preparation and coating method of the corrosion-resistant coating is as follows:

[0053] The 70% fluorocarbon resin, 20% nano-titanium dioxide and 10% additives are mixed in a mass ratio, an appropriate amount of organic solvent is added, and the mixture is stirred in a high-speed mixer for 30 min to prepare a uniform corrosion-resistant coating;

[0054] The corrosion-resistant coating is uniformly sprayed on the outer surface of the aluminum base layer by using a spray gun, and the coating thickness is controlled to be 30 pm. The aluminum base layer coated with the corrosion-resistant coating is placed in an oven and baked at 180℃ for 45 min to cure the corrosion-resistant coating to form a corrosion-resistant coating layer.

[0055] The flexible reinforcing layer is arranged on the inner surface of the aluminum base layer and is woven from aramid fibers. The thickness of the flexible reinforcing layer is 0.3 mm. The aramid fibers have high strength, high modulus and good flexibility, which can effectively enhance the flexibility and tear resistance of the aluminum sheath shielding layer 9.

[0056] Preparation and arrangement method of the flexible reinforcing layer:

[0057] High-strength aramid fibers are selected and woven into a tubular flexible reinforcing layer with a thickness of 0.3 mm by a weaving machine.

[0058] The flexible reinforcing layer is sleeved on the inner surface of the aluminum base layer, and then heat-pressed in a hot press at a temperature of 120℃ and a pressure of 5 MPa for 10 min to tightly combine the flexible reinforcing layer with the aluminum base layer.

[0059] The outer sheath 12 has a thickness of 2 mm and is made of a flame-retardant thermoplastic elastomer polyurethane material.

[0060] The inner lining layer 10 has a thickness of 1.5 mm and is made of a halogen-free low-smoke flame-retardant polyolefin material.

[0061] An oxygen barrier layer is arranged between the inner lining layer 10 and the aluminum sheath shielding layer 9, and has a thickness of 0.8 mm.

[0062] The outer thermal insulation layer 8 has a thickness of 1.0 mm and is made of a polyethylene material.

[0063] The cable core wrapping tape 7 has a thickness of 0.5 mm and is made of a low-smoke halogen-free flame-retardant wrapping tape.

[0064] The inner thermal insulation layer 5 has a thickness of 0.5 mm and is made of a polyethylene material.

[0065] The armor layer 11 is a galvanized steel wire armor layer.

[0066] In the production of the cable, firstly, the round copper wire is drawn into a copper conductor meeting the technical requirements by using a wire drawing and extrusion series process, and the isolation (polyolefin), inner sheath layer (low-density polyethylene), foaming layer (polyethylene physical foaming layer) and outer sheath layer (high-density polyethylene) are extruded and wrapped outside the copper conductor at one time, so as to complete the production of the insulated single wire 1.

[0067] The four insulated single wires 1 of different colors are stranded, and then the embossed tape 2 and the copper-aluminum composite shielding layer 3 are wrapped outside the stranded insulated single wires in sequence, then the current leakage conductor 4 is arranged outside the copper-aluminum composite shielding layer 3, and then an inner thermal insulation layer 5 is wrapped, so as to produce the shielding four-wire group 6.

[0068] The three shielding four-wire groups 6 produced are stranded together by using a high-speed cabling machine to produce a cable core, and then the cable core wrapping tape 7, the outer thermal insulation layer 8, the aluminum sheath shielding layer 9, the inner lining layer 10, the armor layer 11 and the outer sheath 12 are wrapped outside the cable core in sequence, so as to produce the required inner shielding railway digital signal cable.

[0069] In order to ensure that the electrical performance indicators of the cable are qualified, in the production process, the tension of all the shielding four-wire groups in the cable core must be consistent, and the shielding four-wire group cabling pitch is set in the range of 35 times of the outer diameter of the cable core.

[0070] The parts or structures not specifically described in the utility model can be realized by using the prior art or prior products, and will not be repeated here.

[0071] The above is only an embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent structure or equivalent process transformation or direct or indirect application in other related technical fields by using the content of the utility model specification is also included in the patent protection range of the utility model.

Claims

1. A shielded railway digital signal cable, characterized in that, The cable core comprises, from the outside to the inside, an outer sheath, an armor layer, an inner lining layer, an aluminum sheath shielding layer, an outer heat insulation layer, a core wrapping tape, and a core. The core includes several shielded four-wire groups. Each shielded four-wire group includes, from the outside to the inside, an inner heat insulation layer, a copper-aluminum composite shielding layer, an embossed tape, and an insulation unit. The insulation unit includes several insulated single wires twisted together in different colors. A discharge conductor is provided between the inner heat insulation layer and the copper-aluminum composite shielding layer.

2. The internally shielded railway digital signal cable according to claim 1, characterized in that, The aluminum sheath shielding layer includes an aluminum base layer, a corrosion-resistant coating, and a flexible reinforcement layer. The corrosion-resistant coating is applied to the outer surface of the aluminum base layer, and the flexible reinforcement layer is disposed on the inner surface of the aluminum base layer.

3. The internally shielded railway digital signal cable according to claim 2, characterized in that, The aluminum base layer is made of aluminum with a purity of not less than 99.5% and a thickness of 0.5-1.5mm.

4. The internally shielded railway digital signal cable according to claim 2, characterized in that, The thickness of the corrosion-resistant coating is 20-50 μm.

5. The internally shielded railway digital signal cable according to claim 2, characterized in that, The thickness of the flexible reinforcement layer is 0.2-0.5 mm.

6. The internally shielded railway digital signal cable according to claim 1, characterized in that, The stranding pitch of the shielded four-wire group is 35-55 times the outer diameter of the cable core.

7. The internally shielded railway digital signal cable according to claim 1, characterized in that, The outer sheath has a thickness of 1-3 mm; the inner lining has a thickness of 0.5-1.5 mm; the outer insulation layer has a thickness of 0.2-1.0 mm; the inner insulation layer has a thickness of 0.1-0.7 mm; and an oxygen-barrier and flame-retardant layer with a thickness of 0.2-1.0 mm may or may not be provided between the inner lining layer and the aluminum sheath shielding layer.

8. The internally shielded railway digital signal cable according to claim 1, characterized in that, The armor layer is a galvanized steel wire armor layer or a galvanized double steel strip armor layer.

9. The internally shielded railway digital signal cable according to claim 1, characterized in that, The conductivity of the copper-aluminum composite shielding layer is not less than 64% IACS.

10. The internally shielded railway digital signal cable according to claim 1, characterized in that, The insulation unit includes four insulated single wires twisted together in different colors. Each insulated single wire includes a conductor and insulation and isolation layers arranged sequentially from the inside to the outside of the conductor. The insulation is a three-layer co-extruded skin-foam-skin physical foaming structure.

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