A kind of extruded insulation track transportation online monitoring flame-retardant power cable

Abstract

The application discloses a kind of extruded insulation rail transit online monitoring flame-retardant power cable, it is related to power cable technical field, between two adjacent cavity frames and corresponding outside five conductors outside are connected with serpentine spring, two adjacent serpentine springs are connected with outer plastic tube, silicone fireproof glue is filled in outer plastic tube, and outer plastic tube both ends are embedded in the inside of adjacent outer tube respectively, the application is cooperated by cavity frame, serpentine spring, inner plastic tube and expansion strip, so that conductor outside has sufficient heat dissipation flow gap, improve the heat dissipation speed of cable, silicone fireproof glue is filled in outer plastic tube and inner plastic tube, silicone fireproof glue expands to form dense fireproof layer when meeting fire, tightly wrapped in conductor outside, and the expanded fireproof layer will fill the heat dissipation gap between conductor, prevent flame spreading, so that cable has good heat dissipation capacity, also ensure the flame-retardant performance of cable.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically to a flame-retardant power cable with extruded insulation for online monitoring of rail transit. Background Technology

[0002] Common rail transit systems include traditional railways, subways, light rail, and trams. In addition, there are new types of rail transit such as maglev rail systems and monorail systems. Reliable power cables are required for the power transmission of rail transit, and these power cables have high requirements for flame retardancy and fire resistance.

[0003] In the Chinese patent application number CN202020698722.X entitled "A Flame-Retardant Power Cable for Rail Transit", this patent solves the problem of poor heat dissipation performance of ordinary cables by transferring heat outward through the heat dissipation recess on the outside of the support structure. This solves the problem that ordinary cables have poor heat dissipation performance, cannot dissipate heat from the conductor in time, and will accumulate heat. The cables are prone to fire when they are at high temperature for a long time, which can cause damage to people and property.

[0004] The cable conductor in this patent is wrapped inside the support structure, and heat dissipation is only achieved through the connecting cavity and heat dissipation recess. The heat dissipation area is small, and the heat generated by the conductor itself is difficult to diffuse to the outside, resulting in poor heat dissipation of the cable. In addition, flame retardancy is achieved only through the flame retardant layer, which is also ineffective. In order to improve the flame retardant effect, existing flame retardant cables fill the outside with flame retardant powder, which gives the cable better flame retardant performance, but poor heat dissipation capacity. In view of the above shortcomings, there is an urgent need to manufacture a cable that can ensure both heat dissipation and flame retardancy. Summary of the Invention

[0005] This invention provides an extruded insulated flame-retardant power cable for online monitoring of rail transit, which can effectively solve the problems of the above-mentioned patented technology where the cable conductor is wrapped inside the support structure and heat dissipation is only achieved through the connecting cavity and heat dissipation recess, resulting in a small heat dissipation area and difficulty in dissipating the heat generated by the conductor itself to the outside, leading to poor heat dissipation effect of the cable. Furthermore, flame retardancy is only achieved through a flame-retardant layer, resulting in poor flame retardant effect. In order to increase the flame retardant effect, existing flame-retardant cables will fill the outside with flame-retardant powder, which gives the cable better flame retardant performance, but poor heat dissipation capacity.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a flame-retardant power cable for online monitoring of rail transit with extruded insulation, comprising conductors, wherein six conductors are provided, an insulation layer is wrapped around the outside of the conductors, and a heat dissipation and flame-retardant component is provided on the outside of the insulation layer, wherein the heat dissipation and flame-retardant component includes a cavity frame;

[0007] Multiple cavity frames are evenly spaced on the outside of the outer insulating layer. An inner support frame is connected to the inside of the cavity frame through several outer circular tubes. Six wire-splitting rings are provided on the inside of the inner support frame. The six conductors pass through the interior of the six wire-splitting rings respectively. The wire-splitting ring located at the center of the inner support frame is connected to the inner support frame through several inner circular tubes.

[0008] A serpentine spring is connected between two adjacent cavity frames and to the outside of the five corresponding outer conductors. An outer plastic tube is connected between two adjacent serpentine springs. The outer plastic tube is filled with silicone fireproof adhesive. The two ends of the outer plastic tube are respectively embedded in the interior of adjacent outer circular tubes. An expansion strip is filled in the gap between two adjacent outer insulating layers.

[0009] According to the above technical solution, an expansion opening is provided between two adjacent branch rings on the outer side, the expansion strip passes through the interior of the adjacent expansion opening, heat dissipation openings are provided at equal intervals on the surface of the expansion strip, and side openings are provided on both sides of the heat dissipation openings.

[0010] According to the above technical solution, one end of the serpentine spring is welded with a connecting pipe through a connecting plate, and the other end of the serpentine spring is welded with three connecting pieces through a connecting plate. The three adjacent connecting pieces are arranged in a circle, and the connecting pipe and the connecting pieces are located inside the adjacent outer circular tubes. The connecting pieces are embedded inside the adjacent connecting pipes.

[0011] According to the above technical solution, a butt joint is welded to the outside of the mating piece, and three mating interfaces are opened on the outside of the mating pipe, with the butt joint embedded inside the adjacent mating interfaces.

[0012] According to the above technical solution, a number of inner plastic tubes are connected between the centers of two adjacent inner support frames. The inner plastic tubes are located outside the insulation layer of the center, and the inside of the inner plastic tubes is also filled with silicone fireproof adhesive.

[0013] According to the above technical solution, the two ends of the adjacent inner plastic tubes are connected by an assembly ring. The assembly ring is sleeved on the outside of the insulation layer, and one end of the assembly ring is connected to an assembly rod, which is embedded inside the adjacent inner circular tube.

[0014] According to the above technical solution, the cavity frame and the serpentine spring are wrapped with silicone pads on the outside, and multiple restraint rings are sleeved on the outside of the silicone pads at equal intervals.

[0015] According to the above technical solution, an anti-collision and anti-pressure component is provided on the outside of the silicone pad, and the anti-collision and anti-pressure component includes an inner protective sleeve;

[0016] The silicone pad and the restraining ring are wrapped with an inner sheath. Multiple connecting rings are sleeved at equal intervals on the outer side of the inner sheath. Several fixing tubes are welded to the outer side of the connecting rings. A limiting piece is connected between two adjacent fixing tubes. Several sealing tubes are connected to the outer side of two adjacent connecting rings. The two ends of the sealing tubes are embedded inside the adjacent limiting pieces. The inside of the sealing tubes is filled with shear thickening material.

[0017] An arc-shaped strip is connected to the outer side of two adjacent connecting rings and between two adjacent sealing tubes. Several outer layer clips are welded at equal intervals on the top of both sides of the arc-shaped strip. Several inner layer clips are welded at equal intervals on both sides of the arc-shaped strip and at the bottom of the corresponding outer layer clips. The sealing tubes are embedded in the gaps between the adjacent outer layer clips and inner layer clips.

[0018] According to the above technical solution, the connecting ring has a fixing lug welded to its outer sides at both ends and between two adjacent limiting plates, and the arc-shaped strip has a fixing screw connected to both ends. The fixing screw and the fixing lug are connected by a nut.

[0019] According to the above technical solution, the connecting ring and the sealing tube are wrapped with a filling sponge, the filling sponge is wrapped with a woven shielding tape, the woven shielding tape is wrapped with an outer sheath, the outer sheath is wrapped with a spiral tape, and the spiral tape is filled with flame retardant powder and elastic balls.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. Equipped with heat dissipation and flame retardant components, the expansion bar separates adjacent conductors, and the inner plastic tube divides the central conductor and the outer conductors. Together with the expansion bar, this creates gaps between each conductor. A serpentine spring is distributed on the outside of the outer conductor to support the silicone pad, creating gaps between the silicone pad and the outer conductor. The cavity frame, serpentine spring, inner plastic tube, and expansion bar work together to provide ample heat dissipation and circulation gaps on the outside of the conductors. Heat generated by the conductors can directly enter the separated gaps, preventing heat accumulation and improving the cable's heat dissipation speed. Both the outer and inner plastic tubes are filled with silicone fire-retardant adhesive. When the outer and inner plastic tubes are damaged by fire, the silicone fire-retardant adhesive leaks out and adheres to the insulation surface. Upon contact with fire, the silicone fire-retardant adhesive expands, forming a dense fire-retardant layer that tightly wraps around the outside of the conductors. This expanding fire-retardant layer fills the heat dissipation gaps between the conductors, preventing the spread of flames. This ensures the cable has excellent heat dissipation capabilities while also guaranteeing its flame-retardant performance.

[0022] The heat in the gap is conducted to the serpentine spring by natural air convection. The serpentine spring is connected to the outer tube, and the heat on the cavity frame is also conducted to the serpentine spring. The serpentine spring is in contact with the silicone pad. Under the action of heat conduction, the heat on the serpentine spring is conducted to the silicone pad, which guides the heat generated by the conductor to the outside of the cable, further improving the heat dissipation speed of the cable and improving the stability of the cable in use.

[0023] The positions of the five serpentine springs correspond to the positions of the five conductors on the outside. The serpentine springs provide elastic support for the conductors, preventing external forces from acting directly on them. Together with the support of the cavity frame and the inner support frame, they improve the cable's compressive strength. When the cable is bent under stress, the serpentine springs allow the cable to bend at a larger angle, preventing excessive bending. The cable has strong bending resistance. When the external force is removed, the serpentine springs rebound, resulting in good cable toughness.

[0024] 2. Equipped with anti-collision and pressure-resistant components, the sealed tube is filled with shear thickening material, which is a non-Newtonian fluid made of polyethylene glycol and silica composite. Under normal conditions, the shear thickening material is in a flexible fluid state, ensuring the flexibility of the cable. When the shear thickening material is subjected to a large impact force, the viscosity of the shear thickening material increases rapidly, forming a solid protective layer, which enhances the cable's anti-collision capability. The outer and inner clamps limit the two sides of the sealed tube, so that each sealed tube corresponds to the position of each conductor. When the cable is hit during the laying process, it can fully protect the conductor and protect the stability.

[0025] When a cable is subjected to vibration, the shear thickener can absorb the vibration force, reducing fatigue damage to the insulation material caused by vibration. The cable has strong vibration resistance. In addition, the separation of the insulation layer by the split ring, inner plastic tube and expansion strip avoids friction between the insulation layers, reduces frictional heat, and increases the service life of the cable.

[0026] When the cable is subjected to external pressure, the pressure will first act on the spiral strip. The spiral strip is filled with flame-retardant powder and elastic balls. The elastic balls and the spiral strip are made of halogen-free flame-retardant TPE material. The elasticity generated by the spiral strip itself, combined with the elasticity of the elastic balls, can effectively protect the cable. In addition, the arc strip, outer layer clips and inner layer clips are all arc-shaped elastic pieces. When the cable is subjected to pressure, the gap between the outer layer clips and the inner layer clips provides a buffer space, further improving the cable's pressure resistance.

[0027] In summary, the spiral belt, connecting ring, binding ring, and cavity frame are spaced apart and are all made of copper-aluminum alloy. The support components are distributed from the outside to the inside of the cable on the outer, middle, and inner sides to provide rigid support for the cable. When the cable is bent, the arc strip and serpentine spring both have elastic rebound capabilities. The two components work together inside and out, resulting in better compressive strength and toughness of the cable. Attached Figure Description

[0028] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0029] In the attached diagram:

[0030] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0031] Figure 2 This is a schematic diagram of the installation of the silicone pad of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the heat dissipation and flame retardant component of the present invention;

[0033] Figure 4 This is a schematic diagram of the installation structure of the outer plastic tube of the present invention;

[0034] Figure 5 This is a schematic diagram of the installation structure of the outer circular tube of the present invention;

[0035] Figure 6 This is a schematic diagram of the mounting structure of the serpentine spring of the present invention;

[0036] Figure 7 This is a schematic diagram of the installation structure of the inner plastic tube of the present invention;

[0037] Figure 8 This is a schematic diagram of the anti-collision and anti-pressure component of the present invention;

[0038] Figure 9 This is a schematic diagram of the installation structure of the arc-shaped strip of the present invention;

[0039] Figure 10 This is a schematic diagram of the installation structure of the outer clip of the present invention;

[0040] Figure 11 This is a cross-sectional view of the spiral ribbon of the present invention;

[0041] The diagram is labeled: 1. Conductor; 2. Insulating layer;

[0042] 3. Heat dissipation and flame retardant components; 301. Cavity frame; 302. Outer round tube; 303. Inner support frame; 304. Divider ring; 305. Inner round tube; 306. Expansion opening; 307. Connecting plate; 308. Serpentine spring; 309. Butt joint tube; 310. Butt joint piece; 311. Butt joint; 312. Butt interface; 313. Outer plastic tube; 314. Silicone fire retardant; 315. Assembly ring; 316. Assembly rod; 317. Inner plastic tube; 318. Expansion strip; 319. Heat dissipation vent; 320. Side opening; 321. Silicone pad; 322. Restraint ring;

[0043] 4. Anti-collision and pressure-resistant components; 401. Inner sheath; 402. Connecting ring; 403. Fixing tube; 404. Limiting plate; 405. Fixing ear; 406. Arc strip; 407. Fixing screw; 408. Nut; 409. Outer clamping plate; 410. Inner clamping plate; 411. Sealing tube; 412. Shear thickening material; 413. Filling sponge; 414. Braided shielding tape; 415. Outer sheath; 416. Spiral tape; 417. Flame retardant powder; 418. Elastic ball. Detailed Implementation

[0044] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0045] Example: Figure 1-11 As shown, the present invention provides a technical solution for a flame-retardant power cable for online monitoring of rail transit with extruded insulation, including a conductor 1, of which six are provided. The conductor 1 is wrapped with an insulation layer 2. A heat dissipation and flame-retardant component 3 is provided on the outside of the insulation layer 2. The heat dissipation and flame-retardant component 3 includes a cavity frame 301, an outer round tube 302, an inner support frame 303, a branch ring 304, an inner round tube 305, an expansion opening 306, a connecting plate 307, a serpentine spring 308, a butt joint tube 309, a butt joint piece 310, a butt joint 311, a butt interface 312, an outer plastic tube 313, a silicone fireproof adhesive 314, an assembly ring 315, an assembly rod 316, an inner plastic tube 317, an expansion strip 318, a heat dissipation port 319, a side opening 320, a silicone pad 321, and a restraint ring 322.

[0046] Multiple cavity frames 301 are evenly spaced outside the outer insulating layer 2. The inner side of the cavity frame 301 is connected to an inner support frame 303 through several outer circular tubes 302. Six wire-splitting rings 304 are arranged inside the inner support frame 303. Six conductors 1 pass through the interior of the six wire-splitting rings 304 respectively. The wire-splitting ring 304 located at the center of the inner support frame 303 is connected to the inner support frame 303 through several inner circular tubes 305. The cavity frame 301, outer circular tubes 302, inner support frame 303, wire-splitting rings 304 and inner circular tubes 305 are all made of copper-aluminum alloy, which has good elasticity and thermal conductivity.

[0047] A serpentine spring 308 is connected between two adjacent hollow frames 301 and to the outside of the five corresponding outer conductors 1. An outer plastic tube 313 is connected between two adjacent serpentine springs 308. The outer plastic tube 313 is filled with silicone fire-retardant adhesive 314. The two ends of the outer plastic tube 313 are respectively embedded in the interior of the adjacent outer circular tubes 302. Several inner plastic tubes 317 are connected between the centers of two adjacent inner support frames 303. The inner plastic tubes 317 are located outside the central insulation layer 2. The inner plastic tubes 317 are also filled with silicone fire-retardant adhesive 314. The silicone fire-retardant adhesive 314 is a high-performance fire-retardant sealing material. When the outer plastic tube 313 and the inner plastic tube 317 are damaged by fire, the silicone fire-retardant adhesive 314 inside will leak out. The leaked silicone fire retardant 314 adheres to the surface of the insulation layer 2. When the flame burns the silicone fire retardant 314, the silicone fire retardant 314 expands upon contact with the fire to form a dense fire retardant layer that wraps around the outside of the conductor 1. The two ends of the adjacent inner plastic tubes 317 are connected by an assembly ring 315. The assembly ring 315 is sleeved on the outside of the insulation layer 2. One end of the assembly ring 315 is connected to an assembly rod 316. The assembly rod 316 is embedded inside the adjacent inner round tubes 305 to facilitate the connection and fixation of the inner plastic tubes 317. The assembly ring 315 and the assembly rod 316 are made of elastic flame retardant rubber. The inner round tube 305 is elastic. When the inner round tube 305 is under force, the assembly rod 316 cooperates with the inner round tube 305 to improve the elastic support capacity.

[0048] An expansion strip 318 is filled in the gap between two adjacent outer insulation layers 2. The expansion strip 318 is made of elastic flame-retardant rubber and can separate adjacent conductors 1. The inner plastic tube 317 can separate the central conductor 1 and the outer conductor 1. With the expansion strip 318, each conductor 1 has a cavity. An expansion opening 306 is opened between two adjacent outer branch rings 304. The expansion strip 318 passes through the interior of the adjacent expansion opening 306. The expansion opening 306 can limit the expansion strip 318 and fix it stably in the gap between the two adjacent insulation layers 2. Heat dissipation openings 319 are opened at equal intervals on the surface of the expansion strip 318. Side openings 320 are opened on both sides of the heat dissipation openings 319. The heat generated by the conductor 1 itself can enter the interior of the heat dissipation opening 319 through the side openings 320.

[0049] One end of the serpentine spring 308 is welded to a connecting tube 309 via a connecting plate 307, and the other end of the serpentine spring 308 is welded to three connecting pieces 310 via a connecting plate 307. The three adjacent connecting pieces 310 are arranged in a circle. The connecting tube 309 and the connecting pieces 310 are located inside the adjacent outer circular tube 302. The connecting pieces 310 are embedded inside the adjacent connecting tube 309. A connecting head 311 is welded to the outside of the connecting pieces 310. Three connecting interfaces 312 are opened on the outside of the connecting tube 309. The connecting heads 311 are embedded inside the adjacent connecting interfaces 312. The connecting pieces 310 are arc-shaped pieces with elasticity. When the connecting pieces 310 are inserted into the connecting tube 309, the connecting heads 311 will be embedded into the connecting interfaces 312, which facilitates the connection and fixation of the serpentine spring 308.

[0050] The cavity frame 301 and the serpentine spring 308 are wrapped with a silicone pad 321. Multiple binding rings 322 are evenly spaced on the outside of the silicone pad 321. The serpentine spring 308 can support the silicone pad 321, so that there is a cavity between the silicone pad 321 and the outer conductor 1. The silicone pad 321 has good thermal conductivity. The serpentine spring 308 is made of iron, and the heat on the serpentine spring 308 can be conducted to the silicone pad 321.

[0051] The outer side of the silicone pad 321 is provided with an anti-collision and anti-pressure component 4, which includes an inner sheath 401, a connecting ring 402, a fixing tube 403, a limiting piece 404, a fixing ear 405, an arc strip 406, a fixing screw 407, a nut 408, an outer clamping piece 409, an inner clamping piece 410, a sealing tube 411, a shear thickening material 412, a filling sponge 413, a woven shielding tape 414, an outer sheath 415, a spiral tape 416, flame retardant powder 417, and an elastic ball 418.

[0052] The silicone pad 321 and the binding ring 322 are wrapped with an inner sheath 401. Multiple connecting rings 402 are evenly spaced on the outside of the inner sheath 401. Several fixing tubes 403 are welded to the outside of the connecting rings 402. Limiting plates 404 are connected between two adjacent fixing tubes 403. Several sealing tubes 411 are connected to the outside of two adjacent connecting rings 402. The two ends of the sealing tubes 411 are embedded in the inside of the adjacent limiting plates 404. The sealing tubes 411 are filled with shear thickening material 412. Shear thickening material 412 is a non-Newtonian fluid made of polyethylene glycol and silica composite. Referring to existing non-Newtonian speed bumps, shear thickening material 412 is in a flexible fluid state under normal conditions. When shear thickening material 412 is subjected to a large impact force, shear thickening material 412 begins to plastically deform, thereby improving the cable's anti-collision ability.

[0053] An arc-shaped strip 406 is connected to the outside of two adjacent connecting rings 402 and between two adjacent sealing tubes 411. Several outer layer clips 409 are welded at equal intervals on the top of both sides of the arc-shaped strip 406. Several inner layer clips 410 are welded at equal intervals on both sides of the arc-shaped strip 406 and at the bottom of the corresponding outer layer clips 409. The sealing tubes 411 are embedded in the gaps between the adjacent outer layer clips 409 and inner layer clips 410. Fixing ears 405 are welded to the outside of both ends of the connecting ring 402 and between two adjacent limiting pieces 404. Fixing screws 407 are connected to both ends of the arc-shaped strip 406. The fixing screws 407 and fixing ears 405 are connected by nuts 408 to facilitate the connection and fixation of the arc-shaped strip 406 and the connecting ring 402. The connecting ring 402, arc-shaped strip 406, outer layer clips 409 and inner layer clips 410 are made of copper-aluminum alloy to improve the cable's pressure resistance and bending resistance.

[0054] The connecting ring 402 and the sealing tube 411 are wrapped with a filling sponge 413. The filling sponge 413 is wrapped with a braided shielding tape 414. The braided shielding tape 414 is wrapped with an outer sheath 415. The outer sheath 415 is wrapped with a spiral tape 416. The spiral tape 416 is filled with flame-retardant powder 417 and elastic balls 418. The flame-retardant powder 417 is aluminum hydroxide powder. When a fire occurs, the aluminum hydroxide powder decomposes to produce water vapor. The water vapor can dilute the flammable gas around the cable and reduce the burning rate. In addition, the aluminum hydroxide powder burns and forms aluminum oxide that coats the surface of the outer sheath 415, which can further reduce the burning rate. The elastic balls 418 and the spiral tape 416 are made of halogen-free flame-retardant TPE material. Halogen-free flame-retardant TPE material has good flame retardancy and elasticity. When the spiral tape 416 is compressed, the elasticity generated by the spiral of the spiral tape 416 itself, together with the elasticity of the elastic balls 418, can effectively protect the cable.

[0055] The working principle and usage process of this invention: A support strip 318, made of elastic flame-retardant rubber, fills the gap between two adjacent insulating layers 2 on the outer side. This support strip 318 separates adjacent conductors 1. The heat generated by the conductor 1 during operation can enter the heat dissipation port 319 through the side opening 320. The inner plastic tube 317 separates the central conductor 1 from the outer conductors 1. Combined with the support strip 318, this ensures that there is a gap between each conductor 1. A serpentine spring 308 is distributed on the outside of the outer conductor 1. 308 supports the silicone pad 321, creating a gap between the silicone pad 321 and the outer conductor 1. The cavity frame 301, the serpentine spring 308, the inner plastic tube 317, and the expansion strip 318 work together to create a flow gap on the outer side of each conductor 1. Under the action of heat conduction, part of the heat generated by the conductor 1 itself is conducted to the inner support frame 303 and the cavity frame 301, while another part of the heat enters directly into the separated gaps through the insulation layer 2, preventing the heat generated by each conductor 1 from accumulating and improving the heat dissipation speed of the cable.

[0056] The heat in the gap is conducted to the serpentine spring 308 by natural air convection. The serpentine spring 308 is connected to the outer tube 302. The heat on the cavity frame 301 is also conducted to the serpentine spring 308. The serpentine spring 308 is in contact with the silicone pad 321. Under the action of heat conduction, the heat on the serpentine spring 308 is conducted to the silicone pad 321, which guides the heat generated by the conductor 1 to the outside of the cable, further improving the heat dissipation speed of the cable, avoiding heat accumulation that affects the normal operation of the cable, and improving the stability of the cable.

[0057] The positions of the five serpentine springs 308 correspond to the positions of the five conductors 1 on the outside. When the cable is compressed by external force, the serpentine springs 308 can provide elastic support for the conductors 1, avoiding the external force from acting directly on the conductors 1. Together with the support of the cavity frame 301 and the inner support frame 303, the cable's compressive strength is improved. The serpentine springs 308 have good elasticity. When the cable is bent under force, the serpentine springs 308 make the bending angle of the cable larger, avoiding excessive bending of the cable. The cable has strong bending resistance. When the external force is removed, the serpentine springs 308 rebound, and the cable has better toughness.

[0058] In the event of a fire, the spiral band 416 is filled with flame-retardant powder 417, which is aluminum hydroxide powder. During a fire, the aluminum hydroxide powder decomposes to produce water vapor and aluminum oxide. The water vapor dilutes the flammable gases surrounding the cable, and the aluminum oxide coats the surface of the outer sheath 415, reducing the burning rate. When flames enter the cable, both the outer plastic tube 313 and the inner plastic tube 317 are filled with silicone fire-retardant sealant 314, which is a high-performance fire-retardant sealant. When the outer plastic tube 313 and the inner plastic tube 317 are damaged by fire, the silicone fire retardant 314 inside them leaks out. The leaked silicone fire retardant 314 sticks to the surface of the insulation layer 2. When the flame burns the silicone fire retardant 314, the silicone fire retardant 314 expands when exposed to fire to form a dense fire retardant layer that tightly wraps around the outside of the conductor 1. The expanded fire retardant layer fills the heat dissipation gaps between the conductors 1, preventing the spread of flames. The cable has good heat dissipation capacity while also ensuring the flame retardant performance of the cable.

[0059] The sealing tube 411 is filled with shear thickener 412, which is a non-Newtonian fluid made of polyethylene glycol and silica composite. Under normal conditions, shear thickener 412 is a flexible fluid. When shear thickener 412 is subjected to a large impact force, its viscosity increases rapidly, forming a solid protective layer. The cable has strong anti-collision capability. The outer clamp 409 and the inner clamp 410 limit the two sides of the sealing tube 411, so that the sealing tube 411 can be stably fixed, so that each sealing tube 411 corresponds to the position of each conductor 1. When the cable is hit during the laying process, it can fully protect the conductor 1 and has high protection stability.

[0060] Rail transit cables are distributed around trains and are often subjected to vibration. The shear thickener 412 can absorb the vibration force and reduce the fatigue damage of the insulation layer 2 material caused by vibration. In addition, the separation of the insulation layer 2 by the branch ring 304, the inner plastic tube 317 and the expansion strip 318 prevents friction between the insulation layers 2. The cable has strong vibration resistance and no friction between the insulation layers 2 reduces frictional heat, slows down the aging rate of the insulation material, and extends the service life of the cable.

[0061] The spiral band 416 is wound around the outside of the outer sheath 415. When the cable is subjected to external pressure, the pressure will first act on the spiral band 416. The spiral band 416 is filled with flame-retardant powder 417 and elastic balls 418. The elastic balls 418 and the spiral band 416 are made of halogen-free flame-retardant TPE material. Halogen-free flame-retardant TPE material has good flame retardancy and elasticity. When the spiral band 416 is compressed, the elasticity generated by the spiral of the spiral band 416 itself, combined with the elasticity of the elastic balls 418, can provide initial and effective protection for the cable. The cable is protected by arc-shaped strip 406, outer clamp 409, and inner clamp 410, all of which are arc-shaped springs and made of copper-aluminum alloy. When the cable is under pressure, the limiting piece 404 and arc-shaped strip 406 first support the external force. When the pressure is applied to the outer clamp 409, the outer clamp 409 moves closer to the inner clamp 410. The gap between the outer clamp 409 and the inner clamp 410 provides a buffer space, further improving the cable's pressure resistance.

[0062] Spiral ribbon 416, connecting ring 402, binding ring 322 and cavity frame 301 are distributed at intervals and are all made of copper-aluminum alloy. The support components are distributed from the outside to the inside on the outer, middle and inner sides of the cable to provide rigid support for the cable, making the cable more resistant to pressure. When the cable is bent, the arc strip 406 and the serpentine spring 308 have elastic rebound ability. The two work together to further improve the toughness of the cable.

[0063] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flame-retardant power cable for online monitoring of rail transit with extruded insulation, comprising a conductor (1), characterized in that, The conductor (1) is provided in six parts, and the conductor (1) is wrapped with an insulating layer (2) on the outside. A heat dissipation and flame retardant component (3) is provided on the outside of the insulating layer (2). The heat dissipation and flame retardant component (3) includes a cavity frame (301). Multiple cavity frames (301) are evenly spaced outside the outer insulating layer (2). An inner support frame (303) is connected to the inner side of the cavity frame (301) through several outer circular tubes (302). Six wire-splitting rings (304) are provided inside the inner support frame (303). The six conductors (1) pass through the interior of the six wire-splitting rings (304). The wire-splitting ring (304) located at the center of the inner support frame (303) is connected to the inner support frame (303) through several inner circular tubes (305). A serpentine spring (308) is connected between two adjacent cavity frames (301) and to the outside of the five conductors (1) on the corresponding outer side. An outer plastic tube (313) is connected between two adjacent serpentine springs (308). The outer plastic tube (313) is filled with silicone fireproof glue (314). The two ends of the outer plastic tube (313) are respectively embedded in the interior of the adjacent outer round tube (302). The gap between two adjacent insulating layers (2) on the outer side is filled with a support strip (318).

2. The flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 1, characterized in that, An expansion opening (306) is provided between two adjacent branch rings (304) on the outer side. The expansion bar (318) passes through the interior of the adjacent expansion opening (306). Heat dissipation openings (319) are provided at equal intervals on the surface of the expansion bar (318). Side openings (320) are provided on both sides of the heat dissipation openings (319).

3. The flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 1, characterized in that, One end of the serpentine spring (308) is welded to a connecting pipe (309) via a connecting plate (307), and the other end of the serpentine spring (308) is welded to three connecting pieces (310) via a connecting plate (307). The three adjacent connecting pieces (310) are arranged in a circle. The connecting pipe (309) and the connecting pieces (310) are located inside the adjacent outer circular tube (302), and the connecting pieces (310) are embedded inside the adjacent connecting pipe (309).

4. The flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 3, characterized in that, The mating piece (310) has a butt joint (311) welded to its outer side, and the butt joint pipe (309) has three butt joints (312) on its outer side. The butt joint (311) is embedded inside the adjacent butt joints (312).

5. The flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 1, characterized in that, Several inner plastic tubes (317) are connected between the centers of two adjacent inner support frames (303). The inner plastic tubes (317) are located outside the central insulation layer (2), and the inner plastic tubes (317) are also filled with silicone fire retardant glue (314).

6. The flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 5, characterized in that, The two ends of the adjacent inner plastic tubes (317) are connected by an assembly ring (315). The assembly ring (315) is sleeved on the outside of the insulating layer (2). One end of the assembly ring (315) is connected to an assembly rod (316), which is embedded in the interior of the adjacent inner round tube (305).

7. The flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 1, characterized in that, The cavity frame (301) and the serpentine spring (308) are wrapped with silicone pads (321), and multiple restraint rings (322) are evenly spaced on the outside of the silicone pads (321).

8. A flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 7, characterized in that, The silicone pad (321) is provided with an anti-collision and anti-pressure component (4) on the outside, and the anti-collision and anti-pressure component (4) includes an inner sleeve (401). The silicone pad (321) and the restraining ring (322) are wrapped with an inner sheath (401). Multiple connecting rings (402) are evenly spaced on the outer side of the inner sheath (401). Several fixing tubes (403) are welded to the outer side of the connecting rings (402). A limiting piece (404) is connected between two adjacent fixing tubes (403). Several sealing tubes (411) are connected to the outer side of two adjacent connecting rings (402). The two ends of the sealing tubes (411) are embedded inside the adjacent limiting pieces (404). The sealing tubes (411) are filled with shear thickening material (412). An arc-shaped strip (406) is connected to the outside of two adjacent connecting rings (402) and between two adjacent sealing tubes (411). Several outer layer clips (409) are welded at equal intervals on the top of both sides of the arc-shaped strip (406). Several inner layer clips (410) are welded at equal intervals on both sides of the arc-shaped strip (406) and at the bottom of the corresponding outer layer clips (409). The sealing tubes (411) are embedded in the gaps between the adjacent outer layer clips (409) and the inner layer clips (410) on both sides.

9. A flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 8, characterized in that, The connecting ring (402) has a fixing lug (405) welded on both sides of its outer side and between two adjacent limiting pieces (404). The arc strip (406) has a fixing screw (407) connected to both ends. The fixing screw (407) and the fixing lug (405) are connected by a nut (408).

10. A flame-retardant power cable for online monitoring of rail transit with extruded insulation as described in claim 8, characterized in that, The connecting ring (402) and the sealing tube (411) are wrapped with a filling sponge (413), the filling sponge (413) is wrapped with a woven shielding tape (414), the woven shielding tape (414) is wrapped with an outer sheath (415), the outer sheath (415) is wrapped with a spiral tape (416), and the spiral tape (416) is filled with flame retardant powder (417) and elastic balls (418).

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