A thin-wall multi-core shielded cable for railway vehicles and its production method

Abstract

The present disclosure belongs to the technical field of cables, and specifically relates to a thin-walled multi-core shielded cable for railway vehicles and a production method thereof, comprising: a cable body, the cross-section of which is arranged to be a circular structure, a reinforcing core coaxially arranged with the cable body is arranged at the center of the circular structure, and a plurality of wire cores are arranged on the outer side of the reinforcing core in the circumferential direction; a conductor is arranged inside the wire core, a conductor-bearing core for winding the conductor, and a silicone oil coating arranged on the outer side of the conductor and the conductor-bearing core, and the outer side of the conductor is uniformly coated with a dispersion coating; a cable outer layer is arranged on the outside of the cable body, and comprises a shielding layer, a shielding coating and a sheath layer from the inside to the outside.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of cables, and in particular relates to a thin-walled multi-core shielded cable for railway vehicles and a production method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] With the continuous development of high-speed railway technology worldwide, the commercial operating speed of high-speed trains has increased rapidly. The railway operating environment and conditions are extremely complex and diverse, requiring long-distance, continuous, high-speed operation. To ensure the safe operation of railway vehicles, strict safety standards must be designed for trains. This includes fire protection, collision prevention, dynamics, and other aspects to improve train reliability, instability detection, pyrotechnic alarms, axle temperature monitoring, and pantograph video surveillance. According to the principle of "fault-driven safety", the intelligent sensing system is optimized to comprehensively monitor the train's operating conditions and perceive the train's status in real time. This places high demands on the performance of cables used in railway trains. Summary of the Invention

[0004] In order to solve the above problems, the present disclosure proposes a thin-walled multi-core shielded cable for railway vehicles and a production method thereof. Based on the improvement of the structural construction of the cable itself, the cable has special fire-proof performance and has outstanding advantages such as high strength, high wear resistance, easy bending, light weight, small outer diameter, low toxicity, flame retardancy and radiation resistance.

[0005] According to some embodiments, a first solution of the present disclosure provides a thin-walled multi-core shielded cable for railway vehicles, which adopts the following technical solution:

[0006] A thin-walled multi-core shielded cable for railway vehicles, comprising:

[0007] The cable body has a circular cross-section, a reinforcing core coaxially arranged with the cable body is provided at the center of the circular structure, and a plurality of wire cores are provided on the circumferential outer side of the reinforcing core; the wire cores are provided with a conductor, a conductor-carrying core for winding the conductor, and a silicone oil coating provided on the outer sides of the conductor and the conductor-carrying core, and the outer side of the conductor is evenly coated with a dispersion coating;

[0008] The outer layer of the cable is arranged outside the cable body, and comprises a shielding layer, a shielding coating layer and a sheath layer from the inside to the outside.

[0009] As a further technical limitation, the conductor is twisted with Category 5 silver-plated soft copper wires, and the copper wires are twisted with a single-arm suspension twist.

[0010] As a further technical limitation, the dispersion coating adopts 60% concentrated polytetrafluoroethylene dispersion.

[0011] As a further technical limitation, the conductor carrying core is an aramid yarn carrying core, and the conductor is evenly wound on the conductor carrying core at a pitch of 6 times the outer diameter of the conductor.

[0012] As a further technical limitation, a core support is filled between the reinforcing core and the core, and the core support is made of foamed low-smoke halogen-free flame-retardant polyolefin material; lubricating silicone oil is coated on the outside of the insulating core; and a reinforcing core is arranged in the center of the core support.

[0013] As a further technical limitation, the shielding layer adopts uniformly woven silver-plated copper wire to prevent cable signal leakage, and a high-temperature resistant fire-proof coating is uniformly coated on the surface of the shielding layer to form a shielding coating; the shielding coating foams and expands when encountering fire to prevent the high temperature of the external flame from causing internal damage to the cable.

[0014] As a further technical limitation, the sheath layer is made of radiation cross-linked low-smoke halogen-free flame retardant polyolefin, and the polyolefin is irradiated cross-linked after extrusion. The cross-linked thermal elongation index controls the elongation under load to be no more than 175%, and the permanent deformation after cooling to be no more than 15%.

[0015] According to some embodiments, a second solution of the present disclosure provides a method for producing a thin-walled multi-core shielded cable for railway vehicles, using the following technical solution:

[0016] A method for producing a thin-walled multi-core shielded cable for railway vehicles, comprising:

[0017] The surface of the twisted and compressed silver-plated copper wire is coated with polytetrafluoroethylene dispersion and sintered.

[0018] The conductor coated with polytetrafluoroethylene dispersion and sintered is evenly wound on the conductor bearing core at a winding pitch 6 times that of the conductor to form an insulated core;

[0019] placing the formed insulated wire core into the reserved hole in the wire core support;

[0020] Apply silicone oil coating on the surface of the insulating core;

[0021] A shielding layer, a shielding coating layer and a sheath layer are sequentially arranged on the outer side of the wire core support.

[0022] As a further technical limitation, during the process of twisting and compacting the silver-plated copper wire, a single-arm suspended twisting method is adopted, and compaction is performed through a diamond compacting die to control the outer diameter of the strands to the minimum value.

[0023] As a further technical limitation, a reinforcing core is placed in the reserved hole at the center of the core support; a polytetrafluoroethylene dispersion is coated on the outside of the conductor and sintered to form insulation, and the conductor is wound around the aramid wire reinforcing core with a pitch 6 times that of the conductor to form an insulated core.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention adopts silver-plated soft copper conductor, which can not only increase the operating temperature of the cable, but also because the coating metal is silver, silver has excellent conductivity, which can effectively improve the conductivity of the conductor and have lower power loss; an insulating layer is provided to maintain excellent electrical insulation performance, while having excellent flame retardancy and extremely low friction coefficient, effectively reducing damage to the insulating layer during the movement of the core; the tensile strength of the insulating core is improved by providing a conductor bearing core; the tensile strength of the entire cable is improved by providing a central reinforcing core. By providing an outer coating on the insulating core, the overall slippage of the insulating core of the cable is improved. The cable has excellent flexibility and bending resistance. By providing the outer layer of the cable, the shielding effect of the shielding layer is effectively improved, the shielding suppression coefficient is reduced, the flame retardancy and fire resistance of the cable are improved, and the service life of the cable is effectively increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute a part of the present disclosure, are used to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation to the present disclosure.

[0027] Figure 1 1 is a schematic structural diagram of a thin-walled multi-core shielded cable for railway vehicles in the first embodiment of the present disclosure;

[0028] Among them, 1. Silver-plated twisted copper wire, 2. Polytetrafluoroethylene dispersion coating, 3. Aramid wire bearing core, 4. Silicone oil coating, 5. Insulation reserved holes, 6. Reinforced core, 7. Silver-plated copper wire braided shielding layer, 8. High-temperature resistant fire-proof coating, 9. Wire core support, 10. Irradiation cross-linked polyolefin outer sheath. DETAILED DESCRIPTION

[0029] The present disclosure will be further described below with reference to the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are merely relational words determined for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure, and should not be understood as limitations on the present disclosure.

[0033] In this disclosure, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meanings of these terms in this disclosure based on specific circumstances, and they should not be construed as limitations on this disclosure.

[0034] In the absence of conflict, the embodiments of the present disclosure and the features thereof may be combined with each other.

[0035] Example 1

[0036] A first embodiment of the present disclosure introduces a thin-walled multi-core shielded cable for railway vehicles.

[0037] like Figure 1 A thin-wall multi-core shielded cable for railway vehicles is shown, comprising:

[0038] The cable body has a circular cross-section, a reinforcing core coaxially arranged with the cable body is provided at the center of the circular structure, and a plurality of wire cores are provided on the circumferential outer side of the reinforcing core; the wire core is provided with a conductor (in this embodiment, a silver-plated stranded copper wire 1 is used), a conductor bearing core for winding the conductor (in this embodiment, an aramid wire bearing core 3 is used), and a silicone oil coating 4 provided on the outer side of the conductor and the conductor bearing core; the outer side of the conductor is evenly coated with a dispersion coating (in this embodiment, a polytetrafluoroethylene dispersion coating 2 is used);

[0039] The outer layer of the cable is arranged on the outside of the cable body, and from the inside to the outside, it includes a shielding layer (a silver-plated copper wire braided shielding layer 7 is used in this embodiment), a shielding coating (a high-temperature resistant fire-proof coating 8 is used in this embodiment) and a sheath layer (a radiation-cross-linked polyolefin outer sheath 10 is used in this embodiment).

[0040] In one or more embodiments, the conductors are stranded from Category 5 silver-plated annealed copper conductors. The silver-plated copper wires are twisted using a single-arm suspension stranding method and compacted using a diamond compression die. This minimizes the outer diameter of the strands, effectively reducing the outer diameter of the conductor while maintaining conductivity. The use of silver-plated annealed copper conductors not only increases the operating temperature of the cable, but also, due to the excellent conductivity of silver, effectively improves the conductor's conductivity and reduces power loss.

[0041] In one or more embodiments, the insulation layer is evenly coated on the surface of the stranded copper wire using a 60% concentrated polytetrafluoroethylene dispersion and sintered at 380-400°C. The resulting thickness is approximately 0.08 mm. This 60% concentrated polytetrafluoroethylene dispersion is an aqueous polytetrafluoroethylene dispersion containing a nonionic surfactant stabilizer. A modified comonomer is added during the polymerization process. It has a milky white or slightly yellowish appearance and exhibits excellent thermal stability, outstanding chemical inertness, superior electrical insulation properties, and a low coefficient of friction. This not only maintains excellent electrical insulation properties, but also exhibits excellent flame retardancy and an extremely low coefficient of friction, effectively reducing damage to the insulation layer during wire movement. This results in a longer service life.

[0042] In one or more embodiments, the insulated core is uniformly wound around an aramid fiber core. The sintered conductor is evenly wound around the core at a pitch of six times the conductor's outer diameter. This uniform pitch significantly improves the cable's flexibility, allowing for free movement during conductor movement and effectively preventing the copper wire from breaking under stress. The aramid fiber core is a new high-tech synthetic fiber with exceptional properties, including ultra-high strength, high modulus, high-temperature resistance, acid and alkali resistance, and lightweight. Its strength is 5-6 times that of steel wire, its modulus is 2-3 times that of steel wire or fiberglass, its toughness is twice that of steel wire, and its weight is only about one-fifth that of steel wire. It does not decompose or melt at temperatures of 560 degrees Celsius. It offers excellent insulation and aging resistance, resulting in a long lifespan. The inclusion of the core enhances the tensile strength of the insulated core, extending the cable's service life.

[0043] As one or more implementation methods, the core support is extruded from a foamed low-smoke, halogen-free, flame-retardant polyolefin material. Before extrusion, lubricating silicone oil is evenly applied to the insulating core to keep the insulating core moving freely inside the support. This further improves the bending performance of the cable. Core retention holes are set at equal intervals in the 360° circumferential direction of the core support according to the number of insulating cores, and the thickness of the core support is set to approximately 0.5 mm. At the same time, a high-strength aramid wire reinforcement core structure is set at the center of the core support to improve the overall breaking force of the cable.

[0044] In one or more embodiments, a shielding layer is formed by uniformly weaving silver-plated copper wire with a weave density of approximately 85%. The braided layer effectively prevents the influence of external electromagnetic fields on the internal components and prevents internal signal leakage. The silver-plated copper wire coating effectively enhances the shielding effectiveness of the shielding layer and reduces the shielding suppression coefficient.

[0045] In one or more embodiments, a high-temperature, fire-resistant coating is uniformly applied to the shielding layer. This coating foams and expands when exposed to fire, yet remains non-combustible, effectively preventing the spread of flames. This foaming and expansion forms a thermal insulation layer, preventing damage to the cable interior from the high temperatures of external flames, thereby enhancing the cable's flame retardancy and fire resistance.

[0046] In one or more embodiments, the sheath layer utilizes radiation-crosslinked low-smoke, halogen-free, flame-retardant polyolefin. After extrusion, the sheath is crosslinked using an electron accelerator. The crosslinking thermal elongation specification is controlled to achieve an elongation under load of no more than 175%, and a permanent deformation after cooling of no more than 15%. Crosslinking enhances the sheath's physical and mechanical properties and corrosion resistance, providing protection for the entire cable.

[0047] Example 2

[0048] The second embodiment of the present disclosure introduces a method for producing the thin-walled multi-core shielded cable for railway vehicles introduced in the first embodiment.

[0049] A method for producing a thin-walled multi-core shielded cable for railway vehicles, comprising:

[0050] The surface of the twisted and compressed silver-plated copper wire is coated with polytetrafluoroethylene dispersion and sintered.

[0051] The conductor coated with polytetrafluoroethylene dispersion and sintered is evenly wound on the conductor bearing core at a winding pitch 6 times that of the conductor to form an insulated core;

[0052] placing the formed insulated wire core into the reserved hole in the wire core support;

[0053] When forming the reserved hole, a silicone oil coating is applied on the surface of the insulated wire core.

[0054] A shielding layer, a shielding coating layer and a sheath layer are sequentially arranged on the outer side of the wire core support.

[0055] As one or more implementation methods, during the process of twisting and compacting the silver-plated copper wire, a single-arm suspended twisting method is adopted, and compaction is performed through a diamond compacting die to control the outer diameter of the strand to a minimum value.

[0056] As one or more implementation manners, a reinforcing core is placed in a reserved hole at the center of the core support.

[0057] In one or more embodiments, the conductor is coated with a polytetrafluoroethylene dispersion and sintered to form insulation.

[0058] As one or more embodiments, the conductive wire is wound around an aramid fiber reinforcement core at a pitch 6 times that of the conductive wire to form an insulated core.

[0059] As one or more implementation methods, a lubricating silicone oil layer is uniformly coated on the surface of the insulated wire core.

[0060] As one or more implementation methods, during the process of twisting and compacting the silver-plated copper wire, a single-arm suspended twisting method is adopted, and compaction is performed through a diamond compacting die to control the outer diameter of the strand to a minimum value.

[0061] As one or more implementation manners, a reinforcing core is placed in a reserved hole at the center of the core support.

[0062] Although the above describes the specific implementation methods of the present disclosure in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present disclosure. Those skilled in the art should understand that on the basis of the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims

1. A thin-walled multi-core shielded cable for railway vehicles, characterized in that: include: The cable body has a circular cross-section, a reinforcing core coaxially arranged with the cable body is provided at the center of the circular structure, and a plurality of wire cores are provided on the circumferential outer side of the reinforcing core; the wire cores are provided with a conductor, a conductor-carrying core for winding the conductor, and a silicone oil coating provided on the outer sides of the conductor and the conductor-carrying core, and the outer side of the conductor is evenly coated with a dispersion coating; The outer layer of the cable is arranged outside the cable body and comprises a shielding layer, a shielding coating layer and a sheath layer from the inside to the outside; The conductor is twisted with Category 5 silver-plated soft copper wire, and the copper wire is twisted with a single-arm suspension twist method; According to the number of insulated wire cores, wire core retention holes are set at equal intervals in the 360° circumferential direction of the wire core support member, and a high-strength aramid fiber reinforcement core structure is set at the center of the wire core support member; The sheath layer is made of radiation cross-linked low-smoke halogen-free flame-retardant polyolefin, which is irradiated and cross-linked after extrusion. The cross-linked thermal elongation index controls the elongation under load to be no more than 175%, and the permanent deformation after cooling to be no more than 15%; A wire core support is filled between the reinforcing core and the wire core, and the wire core support is made of foamed low-smoke halogen-free flame-retardant polyolefin material; lubricating silicone oil is coated on the outside of the insulating wire core; and a reinforcing core is arranged in the center of the wire core support.

2. A thin-walled multi-core shielded cable for railway vehicles as claimed in claim 1, characterized in that: The dispersion coating adopts 60% concentrated polytetrafluoroethylene dispersion.

3. A thin-walled multi-core shielded cable for railway vehicles as claimed in claim 1, characterized in that: The conductor carrying core is an aramid yarn carrying core, and the conductor is evenly wound on the conductor carrying core at a pitch of 6 times the outer diameter of the conductor.

4. A thin-walled multi-core shielded cable for railway vehicles as claimed in claim 1, characterized in that: The shielding layer uses uniformly woven silver-plated copper wire to prevent cable signal leakage. A high-temperature resistant fire-proof coating is uniformly coated on the surface of the shielding layer to form a shielding coating. The shielding coating foams and expands when exposed to fire to prevent the high temperature of the external flame from causing internal damage to the cable.

5. A method for producing a thin-walled multi-core shielded cable for railway vehicles, for producing a thin-walled multi-core shielded cable for railway vehicles according to any one of claims 1 to 4, characterized in that: include: The surface of the twisted and compressed silver-plated copper wire is coated with polytetrafluoroethylene dispersion and sintered; The conductor coated with polytetrafluoroethylene dispersion and sintered is evenly wound on the conductor bearing core at a winding pitch 6 times that of the conductor to form an insulated core; placing the formed insulated wire core into the reserved hole in the wire core support; Apply silicone oil coating on the surface of the insulating core; A shielding layer, a shielding coating layer and a sheath layer are sequentially arranged on the outer side of the wire core support.

6. A method for producing a thin-walled multi-core shielded cable for railway vehicles as claimed in claim 5, characterized in that: During the process of twisting and compacting the silver-plated copper wire, a single-arm suspended twisting method is adopted and compacted by a diamond compacting die to control the outer diameter of the strands to the minimum.

7. A method for producing a thin-walled multi-core shielded cable for railway vehicles as claimed in claim 5, characterized in that: A reinforcing core is placed in the reserved hole at the center of the core support; a polytetrafluoroethylene dispersion is coated on the outside of the conductor and sintered to form insulation, and the conductor is wound around the aramid fiber reinforcing core at a pitch 6 times that of the conductor to form an insulated core.

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