Compression-resistant and wear-resistant medium-voltage cable

Abstract

The utility model provides a compression-resistant and wear-resistant medium-voltage cable, which comprises a conductor, an insulating layer, a cabling structure, an inner protective layer and an outer sheath, and is characterized in that the conductor adopts a molded wire tightly-pressing conductor structure; the insulating layer is tightly coated on the surface of the conductor; a metal shielding layer is arranged on the outer surface of the insulating layer; the cabling structure comprises insulating wire cores, a framework and aramid yarn, and the framework is supported between the adjacent conductors and arranged on the outer surface of the metal shielding layer in the tangential direction of the conductors; the insulating wire cores are twisted on the framework, the aramid yarn is twisted and filled in a gap between the framework and the metal shielding layer, and the cable is formed by wrapping a copper belt and a water-blocking belt which are overlapped and lapped; the inner protection layer coats the surface of the cabling wire core through extrusion; an armor layer is arranged between the outer sheath and the inner sheath, and the outer sheath wraps the surface of the armor layer. The medium-voltage cable is excellent in compression resistance, wear resistance, tensile strength and the like, effectively solves the technical problem that the existing medium-voltage cable is easy to damage, and has a wide market application prospect.

Description

TECHNICAL FIELD

[0001] The utility model relates to cable technical field especially relates to a pressure -resisting wear -resisting medium voltage cable. BACKGROUND

[0002] At present, most of the medium voltage cable produced by enterprises is conventional insulation + lining + steel belt armoring + sheath, and the structure is relatively simple, mainly composed of conductor, insulation, copper tape shield, inner sheath, armored steel belt and outer sheath. The existing cable structure has obvious deficiencies in pressure resistance and wear resistance. If subjected to external forces such as dragging and extrusion during cable laying, installation and operation, it is very easy to be damaged, which shortens the service life of the cable. Therefore, how to solve the problem of easy damage of medium voltage cable during actual installation and operation is the focus of current cable technology. SUMMARY

[0003] The utility model discloses a medium voltage cable with improved wear resistance and pressure resistance to solve the problem of easy damage of medium voltage cable.

[0004] To achieve the above purpose, the utility model provides a pressure -resisting wear -resisting medium voltage cable, including conductor, insulation layer, cable structure, inner protective layer and outer sheath:

[0005] The conductor adopts a profiled wire tight conductor structure, the insulation layer is tightly covered on the surface of the conductor, and a metal shielding layer is arranged on the outer surface of the insulation layer.

[0006] The cable structure includes an insulated wire core, a framework and aramid yarn, the framework is supported between adjacent conductors and arranged on the outer surface of the metal shielding layer along the tangent direction of the conductor.

[0007] The insulated wire core is twisted on the framework, and the aramid yarn is twisted and filled in the gap between the framework and the metal shielding layer, and the cable is combined by overlapping and wrapping copper tape and water blocking tape.

[0008] The inner protective layer is extruded and covered on the surface of the cable core by thermoplastic polyurethane rubber, and the armored layer is arranged between the outer sheath and the inner protective layer, and the outer sheath is covered on the surface of the armored layer.

[0009] Further, the conductor is made of copper rod wire drawing and twisting, and the conductor surface should be smooth, oil-free, damage-free insulation burr and sharp edge. The conductor adopts a profiled wire tight conductor structure, which reduces the cross section and outer diameter and saves materials.

[0010] Further, the inner surface and the outer surface of the insulation layer are respectively provided with a semi-conductive inner shield and a semi-conductive outer shield; the insulation layer adopts an extrusion coating structure, the cross-linked polyethylene is extruded together with the semi-conductive inner shield and the semi-conductive outer shield at high pressure to tightly coat the surface of the conductor to form an insulation integrated structure, and the insulation performance is improved.

[0011] Further, the metal shielding layer is composed of one layer of overlapped and wrapped soft copper band, the wrapping is continuous, uniform, smooth, and has no fracture, the copper band covering rate is not less than 15%, and the copper band should be wound or welded.

[0012] Further, in the cabling structure, the framework is a polyethylene framework, the cabling direction is right, the insulated core is twisted along the polyethylene framework (PE framework), and the twisted aramid yarn is filled at the gap, the filling should be dense and round, the copper band and the water-blocking band are overlapped and wrapped, and the overlapping rate is not less than 15%.

[0013] Further, the inner protective layer adopts a TPU sheath material coating structure, and the TPU material is extruded and coated on the surface of the cabling core.

[0014] Further, the armor layer adopts a double-layer gap wrapping structure of galvanized steel band; the double-layer galvanized steel band or painted steel band (non-magnetic metal band is applied to single-core cables) is spirally and rotationally wrapped to form two layers, and the middle of the outer steel band is substantially above the gap between the inner steel band; the steel band gap should be not more than 50% of the width of the steel band.

[0015] Further, the outer sheath adopts an extrusion coating structure, and the thermoplastic polyurethane rubber TPU material is extruded and stretched to form a sheath structure and is shrink-wrapped on the surface of the armor layer.

[0016] The process flow of the medium voltage cable in the utility model is:

[0017] 1) conductor: copper rod drawing and twisting are adopted to ensure that the surface is smooth, free of oil stains, and has no damage to the insulation burr and sharp edge.

[0018] 2) insulation layer: an extrusion coating structure is adopted, the cross-linked polyethylene is extruded together with the inner and outer shields at high pressure, and is tightly coated on the surface of the conductor to form an insulation integrated structure. The average value of the coating thickness should be not less than the nominal value, the thinnest point thickness should be not less than 90% of the nominal thickness, and the eccentricity should be not more than 10%. The extrusion coating surface should be smooth, without sharp corners, particles, burning, scratches and the like.

[0019] 3) metal shielding layer: the copper band shielding layer is composed of one layer of overlapped and wrapped soft copper band, the wrapping is continuous, uniform, smooth, and has no fracture, the copper band covering rate is not less than 15%. The copper band should be wound or welded.

[0020] 4)Cabling structure: the cabling direction is right, the insulated core is twisted along the PE skeleton and filled with twisted aramid yarn at the gap, the filling should be dense and round, and the outer part is wrapped with overlapping copper tape and water-blocking tape, and the overlapping rate is not less than 15%.

[0021] 5)Inner protective layer: TPU material is extruded and wrapped on the surface of the cabling core, the average value of the wrapping thickness should be not less than the nominal value, and the thickness at the thinnest point should be not less than 90% of the nominal thickness, and the extrusion surface should be smooth without particles, burning, scratches and the like.

[0022] 6)Armoring layer: the metal tape armoring adopts double-layer galvanized steel tape or painted steel tape (non-magnetic metal tape is applied to single-core cable), and is spirally wrapped in two layers, the middle of the outer steel tape is approximately above the gap between the inner steel tapes, the steel tape gap should be not more than 50% of the width of the steel tape, and the nominal thickness of the steel tape should meet the provisions of the national standard GB / T12706.

[0023] 7)Outer protective jacket: the extrusion pipe wrapping structure is adopted, TPU material is extruded and stretched to form a protective jacket structure, and the protective jacket structure is shrunk and wrapped on the surface of the armoring layer, the average value of the wrapping thickness should be not less than the nominal value, and the thickness at the thinnest point should be not less than 90% of the nominal thickness, and the extrusion surface should be smooth without sharp corners, particles, burning, scratches and the like.

[0024] Compared with the prior art, the utility model has the advantages that:

[0025] 1)The aramid yarn is twisted and filled in the cabling gap, so that the tensile strength of the cable is greatly improved; the PE skeleton is arranged as a support, so that the protective effect is good, the insulated core is not damaged when the cable is subjected to external pressure, the pressure resistance and wear resistance of the cable are effectively improved, the maintenance cost is reduced, the service life of the cable is prolonged, and the safety hidden danger is reduced.

[0026] 2)The elastomer material TPU is used as the inner protective layer and the outer protective jacket structure, compared with the general PVC protective jacket or PE protective jacket, the TPU protective jacket is softer, more environmentally friendly and more wear-resistant.

[0027] 3)The utility model has the advantages of simple structure, convenient implementation, wide application range, large-scale production, excellent performance in pressure resistance, wear resistance and tensile resistance, effectively solves the technical problem that the existing medium-voltage cable is easy to be damaged, and has wide market application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a structure schematic view of the medium-voltage cable with pressure resistance and wear resistance of the utility model embodiment;

[0029] Figure 2 It is a process flow chart of the medium-voltage cable with pressure resistance and wear resistance of the utility model embodiment. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be further described below.

[0031] This embodiment proposes a pressure-resistant and wear-resistant medium-voltage cable, such as... Figure 1 As shown, the medium-voltage cable includes a conductor 1, an insulation layer 3, a cabling structure, an inner sheath 9, and an outer sheath 11. The conductor 1 is a profiled conductor with a compressed conductor structure. The inner surface of the insulation layer 3 is provided with a semi-conductive inner shield 2, and the outer surface is provided with a semi-conductive outer shield 4. The insulation layer 3 adopts an extrusion-coated structure, which is formed by simultaneously high-pressure extrusion of cross-linked polyethylene along with the semi-conductive inner shield 2 and the semi-conductive outer shield 4, tightly wrapping it on the surface of the conductor 1 to form an integrated insulation structure, thereby improving the insulation performance. The outer surface of the insulation layer 3 is provided with a metal shielding layer 5, which is a copper tape shielding layer.

[0032] In addition, the cable structure includes insulated wire cores, PE skeleton 6, and aramid yarn 7, such as Figure 1 As shown, the PE skeleton 6 is supported between adjacent conductors 1 and is located on the outer surface of the metal shielding layer along the tangential direction of conductor 1. The insulated core is twisted onto the PE skeleton 6, and the twisted aramid yarn 7 is filled into the gap between the PE skeleton 6 and the semi-conductive outer shield 4. The cable is formed by wrapping the cable with an overlapping water-blocking tape 8. The inner sheath 9 adopts a TPU sheathing structure, in which TPU material is extruded and wrapped onto the surface of the cable core. The outer surface of the inner sheath 9 is covered with a steel tape armor layer 10, which is located between the inner sheath 9 and the TPU outer sheath 11 and adopts a double-layer gap wrapping structure with galvanized steel tape. It is formed by spirally wrapping two layers of double-layer galvanized steel tape or painted steel tape (non-magnetic metal tape is used for single-core cables). The outer sheath 11 adopts an extrusion wrapping structure, in which thermoplastic polyurethane rubber (TPU) material is extruded and stretched to form a sheath structure, which is then shrunken and wrapped onto the outer surface of the armor layer 10.

[0033] In this embodiment, conductor 1 is made of copper rod drawn and stranded. The surface of the conductor should be smooth, free of oil stains, and free of burrs or sharp edges that could damage the insulation. The conductor adopts a profiled wire compression conductor structure to reduce the cross-section and outer diameter, thus saving materials.

[0034] In this embodiment, the metal shielding layer consists of a layer of overlapping and wrapped soft copper strips. The wrapping is continuous, uniform, flat, smooth, and without breaks. The copper strip overlap rate is not less than 15%, and the copper strips are connected by welding.

[0035] In the cabling structure, the cabling direction is right-handed. The insulated cores are twisted along the PE skeleton (polyethylene skeleton) and filled with twisted aramid yarn in the gaps. The filling should be dense and round. The outer layer is wrapped with overlapping water-blocking tape with an overlap rate of not less than 15%.

[0036] As Figure 2 shown, the process flow of the power cable in this embodiment includes the following steps:

[0037] 1) Conductor 1 production: The tight conductor is formed by drawing and twisting copper rods. During the process, the surface of the conductor 1 is smooth, free of oil stains, and has no damaged insulation burrs or sharp edges.

[0038] 2) Insulation layer 2 production: The cross-linked polyethylene is simultaneously high-pressure extruded with the inner and outer shields to form a tight insulation structure on the surface of the conductor. The average value of the coating thickness should not be less than the nominal value, the thinnest point thickness should not be less than 90% of the nominal thickness, and the eccentricity should not be greater than 10%. The extrusion surface should be smooth, without sharp corners, particles, burning, scratches, etc.

[0039] 3) Metal shielding layer 3 production: The soft copper tape is wrapped around one layer to form a copper tape shield. During the wrapping process, the wrapping is continuous, uniform, smooth, and without breakage, and the copper tape overlap rate is not less than 15%. The copper tape connection is achieved by welding.

[0040] 4) Cabling: The insulated core is twisted on the PE skeleton 6, and the twisted aramid yarn 7 is filled in the gap between the PE skeleton 6 and the semi-conductive outer shield 4, and then the outer water-blocking tape 8 is wrapped to form a cabling structure. The cabling direction is right, the filling should be dense and round, and the water-blocking tape wrapping overlap rate should be not less than 15%.

[0041] 5) TPU inner protective layer 9 production: TPU material is extruded and coated on the surface of the cabling core. The average value of the coating thickness should not be less than the nominal value, the thinnest point thickness should not be less than 90% of the nominal thickness, and the extrusion surface should be smooth, without particles, burning, scratches, etc.

[0042] 6) Armoring layer 10 generation: Double-layer galvanized steel tape or painted steel tape (non-magnetic metal tape for single-core cable) is spirally wrapped to form a steel tape armoring layer. The outer steel tape is roughly above the inner steel tape gap, the steel tape gap should be not greater than 50% of the steel tape width, and the nominal thickness of the steel tape should comply with the provisions of GB / T12706.

[0043] 7) Outer sheath 11 generation: TPU material is extruded and stretched to form a sheath structure, which is shrink-wrapped on the surface of the armoring layer 10. The average value of the extrusion thickness should not be less than the nominal value, the thinnest point thickness should not be less than 90% of the nominal thickness. The extrusion surface should be smooth, without sharp corners, particles, burning, scratches, etc.

[0044] The above are only preferred embodiments of the present application, and do not have any limiting effect on the present application. Any person skilled in the art, without departing from the technical scheme of the present application, makes any form of equivalent replacement or modification of the technical scheme and technical content disclosed by the present application, and the variation belongs to the content of the technical scheme of the present application, and still belongs to the protection scope of the present application.

Claims

1. A pressure-resistant and wear-resistant medium voltage cable, characterized in that, The cable comprises a conductor, an insulation layer, a cabling structure, an inner protective layer and an outer sheath. The conductor adopts a profiled compact conductor structure; the insulation layer is tightly wrapped on the surface of the conductor; a metal shielding layer is arranged on the outer surface of the insulation layer. The cabling structure comprises an insulated core, a framework and aramid yarns; the framework is supported between adjacent conductors and arranged on the outer surface of the metal shielding layer along the tangential direction of the conductor; The insulated core is twisted on the framework; the aramid yarns are twisted and filled in the gap between the framework and the metal shielding layer, and combined into a cable through an outer wrapping of overlapping copper strips and water-blocking tapes; The inner protective layer is extruded by thermoplastic polyurethane rubber and wrapped on the surface of the cabling core; the outer sheath and the inner protective layer are provided with an armor layer, and the outer sheath is wrapped on the surface of the armor layer.

2. A crush and abrasion resistant medium voltage cable according to claim 1, characterized in that, The inner and outer surfaces of the insulation layer are respectively provided with semi-conductive inner and outer shields; the insulation layer adopts an extrusion wrapping structure, and cross-linked polyethylene is extruded together with the semi-conductive inner and outer shields under high pressure.

3. The crush and abrasion resistant medium voltage cable of claim 1, wherein, The metal shielding layer is composed of one layer of overlapping wrapping soft copper strips, and the copper strip coverage rate is not less than 15%.

4. The crush and abrasion resistant medium voltage cable of claim 1, wherein, In the cabling structure, the framework is a polyethylene framework, the cabling direction is right, and the wrapping overlap rate is not less than 15%.

5. The crush and abrasion resistant medium voltage cable of claim 1, wherein, The armor layer is formed by spirally wrapping two layers of double-layer galvanized steel strips or painted steel strips, and the gap between the steel strips is not more than 50% of the width of the steel strip.

6. The crush and abrasion resistant medium voltage cable of claim 1, wherein, The outer sheath adopts an extrusion wrapping structure, and the sheath structure is formed by extruding and stretching thermoplastic polyurethane rubber material.

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