B1-level flame-retardant tensile medium-voltage power cable for rail transit signals

Abstract

The utility model relates to a B1-level flame-retardant tensile medium-voltage power cable for rail transit signals. The power cable comprises a plurality of insulating wire cores, each insulating wire core comprises a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer and a metal shielding layer from inside to outside, the plurality of insulating wire cores are wrapped by two layers of halogen-free flame-retardant wrapping tapes to form a cable core, and gaps among the plurality of insulating wire cores are filled with high-flame-retardant fillers. A high-flame-retardant oxygen barrier layer is extruded outside the cable core, a steel wire armor layer is sparsely wound outside the high-flame-retardant oxygen barrier layer, and a sheath layer is extruded outside the steel wire armor layer. The cable is low in flame spread, small in heat release amount, small in heat release rate, halogen-free and flame-retardant in material, small in total smoke production amount, low in smoke density, green and environment-friendly, and is widely applied to traffic command and control signal transmission in urban subway projects.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a B1-level flame-retardant and tensile-resistant medium-voltage power cable for rail transit signals. Background Art

[0002] There will be great demand for rail transit cables in the market in the future.

[0003] Low smoke spread and high safety flame-retardant cables for rail transit are installed and laid in a closed and narrow underground space with dense personnel and large flow of people. Due to the particularity of the usage scenario, the product needs to have more excellent high flame retardancy and high safety performance requirements on the basis of conventional A-level flame retardancy, and the combustion performance classification must reach the highest level B1 for plastic insulated cables. Utility Model Content

[0004] The utility model aims to provide a B1-class flame-retardant and tensile-resistant medium-voltage power cable for rail transit signals, which has low flame spread, low heat release, low heat release rate, halogen-free flame-retardant materials, low total smoke production, low smoke density, and is green and environmentally friendly.

[0005] The technical scheme of the utility model is: a B1-level flame-retardant and tensile-resistant medium-voltage power cable for rail transit signals, wherein the power cable comprises a plurality of insulating cores, wherein the insulating cores comprise a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, and a metal shielding layer from the inside to the outside, wherein the plurality of insulating cores are wrapped into a cable core by two layers of halogen-free flame-retardant wrapping tapes, a high flame-retardant filling is arranged in the gaps between the plurality of insulating cores, a high flame-retardant oxygen-insulating layer is extruded outside the cable core, a steel wire armor layer is sparsely wound outside the high flame-retardant oxygen-insulating layer, and a sheath layer is extruded outside the steel wire armor layer.

[0006] Furthermore, the conductor meets the requirements of GB / T 3956-2008 for Class 2 high-quality conductors, with a copper content of ≥99.95%.

[0007] Furthermore, the metal shielding layer is a combination structure of copper wire sparse winding shielding and copper tape shielding, and the average overlap rate of the copper tape shielding is ≥20%.

[0008] Furthermore, the sheath layer is a low-smoke, halogen-free, B1-grade flame-retardant polyolefin sheath with an oxygen index of more than 38.

[0009] The utility model has the following beneficial effects: low flame spread, low heat release, low heat release rate, halogen-free flame retardant material, low total smoke production, low smoke density, and is green and environmentally friendly. It is widely used in urban subway projects to transmit traffic command and control signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the utility model.

[0011] In the figure, 1 is the conductor, 2 is the conductor shielding layer, 3 is the insulating layer, 4 is the insulating shielding layer, 5 is the metal shielding layer, 6 is the high flame retardant filling, 7 is the oxygen insulation layer, 8 is the steel wire armor layer, and 9 is the sheath layer. DETAILED DESCRIPTION

[0012] A B1-grade flame-retardant and tensile-resistant medium-voltage power cable for rail transit signals, the power cable comprising a plurality of insulated cores, the insulated cores comprising a conductor 1, a conductor shielding layer 2, an insulating layer 3, an insulating shielding layer 4, and a metal shielding layer 5 from the inside to the outside, the plurality of insulated cores being wrapped into a cable core with two layers of halogen-free flame-retardant wrapping tapes, a high flame-retardant filling 6 being arranged in the gaps between the plurality of insulated cores, a high flame-retardant oxygen-insulating layer 7 being extruded outside the cable core, a steel wire armor layer 8 being sparsely wound outside the high flame-retardant oxygen-insulating layer 7, and a sheath layer 9 being extruded outside the steel wire armor layer 8.

[0013] The conductor 1 meets the requirements of GB / T 3956-2008 for a Class 2 high-quality conductor, and has a copper content of ≥99.95%.

[0014] The metal shielding layer 5 is a combination structure of copper wire sparsely wound shielding and copper tape shielding, and the average overlap rate of the copper tape shielding is ≥20%, so that the control cable has anti-interference performance and super tensile strength.

[0015] The sheath layer 9 is a low-smoke halogen-free B1 grade flame-retardant polyolefin sheath with an oxygen index of more than 38, and has high mechanical strength, ensuring that the tensile strength and elongation at break of the cable under thermal aging meet the requirements. The low-smoke halogen-free B1 grade flame-retardant polyolefin sheath material has low smoke production, low smoke toxicity, low halogen content, low corrosiveness, and good environmental performance under flame conditions, ensuring that the overall combustion performance of the cable meets the B1 requirements.

[0016] The conductor shielding layer 2 and the insulating shielding layer 4 are made of high-quality semi-conductive material with performance higher than the national standard requirements. The insulating material is water-tree resistant insulating material, which can greatly extend the service life of the cable.

[0017] When the cable is made, two layers of halogen-free flame-retardant wrapping tape are used for wrapping, with an overlap rate of ≥20%, to wrap the insulated core tightly to prevent the cable core from loosening when the cable is laid in a narrow underground space.

[0018] The oxygen index of the oxygen-isolating layer 7 is above 45. The oxygen-isolating layer 7 has a high oxygen index and is difficult to be ignited by flames. It can also isolate oxygen, reduce the damage of flames to the insulation layer inside the cable core, and ensure the normal operation of the cable.

[0019] In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] In the present invention, unless otherwise clearly stipulated and limited, for example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0021] The standard parts used in the utility model can all be purchased from the market, and the special-shaped parts can all be customized according to the description and the drawings.

[0022] Although 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.B1 flame retardant tensile medium voltage power cable for rail transit signal, characterized by: The power cable comprises a plurality of insulated wire cores, wherein the insulated wire cores comprise, from the inside to the outside, a conductor (1), a conductor shielding layer (2), an insulating layer (3), an insulating shielding layer (4), and a metal shielding layer (5); the plurality of insulated wire cores are wrapped with two layers of halogen-free flame-retardant wrapping tape to form a cable core; a high flame-retardant filler (6) is arranged in the gaps between the plurality of insulated wire cores; a high flame-retardant oxygen-insulating layer (7) is extruded outside the cable core; a steel wire armor layer (8) is sparsely wound outside the high flame-retardant oxygen-insulating layer (7); and a sheath layer (9) is extruded outside the steel wire armor layer (8); The conductor (1) is a Class 2 high-quality conductor that meets the requirements of GB / T 3956-2008, with a copper content of ≥99.95%; The metal shielding layer (5) is a combination structure of copper wire sparsely wound shielding and copper tape shielding, and the average overlap rate of the copper tape shielding is ≥20%; The sheath layer (9) is a low-smoke, halogen-free, B1-grade flame-retardant polyolefin sheath with an oxygen index of more than 38.

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