A flame-retardant B1-level special fire-resistant cable for subways

Abstract

The present invention discloses a flame-retardant B1-level special fire-resistant cable for subways, specifically relating to the technical field of cables. The cable body includes a cable core, and there are several cable cores. A layer of insulating layer is wrapped around each of the several cable cores. A layer of flame-retardant filling layer is wrapped around the several insulating layers. A layer of flame-retardant layer is wrapped around the flame-retardant filling layer. A layer of outer sheath is wrapped around the flame-retardant layer. Through the arrangement of structures such as the first telescopic member and the second telescopic member in the present invention, when a fire occurs and the outer sheath is burned out, the first limiting member and the second limiting member can be made to move away from each other and no longer play a limiting role. And the plug connector whose limit is released is pushed out of the plug slot through the pushing plate, thereby completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, reducing the overall damage, minimizing the power outage range, ensuring the power supply in the non-fire area, reducing the overall impact of the fire on the subway system, thereby reducing property losses and ensuring the safety of passengers.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and more specifically, to a fire-retardant B1-class special fire-resistant cable for subways. Background Art

[0002] "B1" usually represents a B1-class fire-retardant cable in the cable model. B1-class cables have good fire-retardant performance under fire conditions, can effectively prevent the spread of fire, and compared with other fire-retardant grades, B1-class cables produce less smoke, lower toxicity, less corrosion during combustion, and there are no burning drips during the combustion process, which can better ensure safety. As an important part of urban public transportation, cables are crucial for the safe, punctual, and comfortable operation of subways, as well as for the urban traffic order and the travel experience of citizens.

[0003] Chinese Patent with application number CN202011621612.4 discloses a halogen-free low-smoke fire-retardant B1-class fire-resistant cable for key projects of subways and light rails, which includes an outer sheath, an armor layer, an inner lining layer, and a wrapping layer from outside to inside. There are multiple cable cores in the wrapping layer, and the cable cores include an insulating layer, a fire-resistant layer, and a conductor from outside to inside; the insulating layer is made of cross-linked polyethylene; the fire-resistant layer is made of mica tape; the wrapping layer is a halogen-free high-resistance tape; the outer sheath is made of a halogen-free fire-retardant material; the armor layer is a copper tape; there is also a filling material in the wrapping layer, and the filling material is a halogen-free low-smoke high-fire-retardant PP rope. The cable of this application has good fire-retardant and fire-extinguishing effects.

[0004] Although the above invention can achieve fire-retardant and fire-extinguishing effects, when a serious fire occurs in the cable, there will still be a phenomenon that the fire spreads to other non-damaged areas, which will expand the fire range, produce more smoke and flames, cause difficulties in passenger evacuation, increase the risk of casualties, and the severely burned cable cannot be restored through simple repair, and the cable needs to be repaired and replaced. The repair and replacement steps are relatively cumbersome, which will lead to partial or complete suspension of operation of the subway line, causing traffic inconvenience and increasing the burden on other means of transportation.

[0005] The present invention provides a fire-retardant B1-class special fire-resistant cable for subways, aiming to solve the problems of fire spreading to other non-damaged areas, causing difficulties in passenger evacuation, increasing the risk of casualties, and the relatively cumbersome steps of cable repair and replacement, resulting in traffic inconvenience and increasing the burden on other means of transportation. Summary of the Invention

[0006] The object of the present invention is to provide a flame-retardant B1-class special fire-resistant cable for subways, so as to solve the problems proposed in the above background technology that the fire spreads to other non-damaged areas, causing difficulties in the evacuation of passengers, increasing the risk of casualties, and the steps of cable maintenance and replacement are relatively cumbersome, resulting in inconvenient transportation and increasing the burden on other means of transportation.

[0007] To achieve the above object, the present invention provides the following technical solution: A flame-retardant B1-class special fire-resistant cable for subways, including a cable body. The cable body includes a plurality of cable cores. The cable cores are provided with a plurality of them. A layer of insulating layer is wrapped outside each of the plurality of cable cores. A layer of flame-retardant filling layer is wrapped outside the plurality of insulating layers. A layer of flame-retardant layer is wrapped outside the flame-retardant filling layer. A layer of outer sheath is wrapped outside the flame-retardant layer. The two ends of the cable body are respectively provided with a first plug-in part and a second plug-in part, and adjacent two cable bodies can be docked.

[0008] The first plug-in part includes a plug joint opened at one end of the outer sheath. The second plug-in part includes a plug slot opened at the other end of the outer sheath away from the plug joint. A plurality of first limiting grooves are equidistantly opened on the outer peripheral side of the plug joint. A plurality of second limiting grooves with the same number as the first limiting grooves are equidistantly opened on the inner peripheral side of the plug slot. A first limiting member is arranged in each of the first limiting grooves. A second limiting member is arranged in each of the second limiting grooves. When the plug joint of one of the cable bodies is completely inserted into the plug slot of the other cable body, the positions of the plurality of first limiting grooves and the plurality of second limiting grooves correspond to each other, and the plurality of first limiting members and the plurality of second limiting members can extend out for limiting.

[0009] Preferably, a first installation groove is opened on the outer peripheral side of the plug joint, a second installation groove is opened on the inner peripheral side of the plug slot, a first airbag is embedded in the first installation groove, a second airbag is embedded in the second installation groove, and a plurality of support rods are fixedly connected to the inner walls of the first airbag and the second airbag at equal intervals. When the plug joint of one of the cable bodies is completely inserted into the plug slot of the other cable body, the first installation groove and the second installation groove are in corresponding positions, and a seal can be formed between the first airbag and the second airbag.

[0010] Preferably, a first sealing plate is fixedly connected to one side of the first limiting member located inside the first limiting groove, and the first sealing plate is hermetically slidably connected in the first limiting groove. A second sealing plate is fixedly connected to one side of the second limiting member located inside the second limiting groove, and the second sealing plate is hermetically slidably connected in the second limiting groove.

[0011] Preferably, a first telescopic groove is formed on one side of the first limiting member outside the first limiting groove, a first telescopic member is hermetically and slidably connected in the first telescopic groove, a second telescopic groove is formed on one side of the second limiting member outside the second limiting groove, and a second telescopic member is hermetically and slidably connected in the second telescopic groove.

[0012] Preferably, sealing grooves with the same number and corresponding positions as the plug connectors are formed inside the outer sheath, and the plurality of sealing grooves are all communicated with the interiors of the corresponding first limiting grooves and the corresponding second limiting grooves, and the plurality of sealing grooves are all communicated with the first airbag and the second airbag.

[0013] Preferably, both sides of the first limiting member outside the first limiting groove and along the length direction of the cable body are provided with wedge-shaped surfaces, and both sides of the second limiting member outside the second limiting groove and along the length direction of the cable body are provided with wedge-shaped surfaces;

[0014] One side of the first telescopic member outside the first telescopic groove is provided with an arc surface, and one side of the second telescopic member outside the second telescopic groove is provided with an arc surface.

[0015] Preferably, when the plug connector is inserted into the inside of the plug socket, the plug connector can cooperate with the wedge-shaped surface of the first limiting member and the arc surface of the first telescopic member to enable the first limiting member to slide inside the first limiting groove, so that the first telescopic member slides inside the first telescopic groove, and the plug socket can cooperate with the wedge-shaped surface of the second limiting member and the arc surface of the second telescopic member to enable the second limiting member to slide inside the second limiting groove, so that the second telescopic member slides inside the second telescopic groove.

[0016] Preferably, push grooves are formed at both ends of the flame retardant layer, push plates are hermetically and slidably connected in the two push grooves, inert gas is filled between each push groove and the corresponding push plate, inert gas is filled in each sealing groove, inert gas is filled between each first telescopic groove and the corresponding first telescopic member, inert gas is filled between each second telescopic groove and the corresponding second telescopic member, and the air pressure of the inert gas in each sealing groove is greater than the gas of the expansion gas in the corresponding first telescopic groove and the corresponding second telescopic groove.

[0017] Preferably, when the plug connector is completely inserted into the plug socket, each first limiting member and the corresponding second limiting member are arranged in an interleaved manner, each first telescopic member can contact the surface of the corresponding second sealing plate, and each second telescopic member can contact the surface of the corresponding first sealing plate.

[0018] Preferably, a docking male head is sleeved between one end of each cable core inside the plug and the corresponding insulating layer, and a docking female head is sleeved between one end of each cable core inside the socket groove and the corresponding insulating layer. The docking male head can be inserted into the docking female head for electrical connection.

[0019] Technical effects and advantages of the present invention:

[0020] 1. Through the arrangement of structures such as the first limiting member and the second limiting member in the present invention, when the plug is completely inserted into the socket groove, the positions of multiple first limiting grooves and multiple second limiting grooves will correspond, so that multiple first limiting members and corresponding second limiting members are arranged in an alternating manner. At this time, multiple first limiting members and multiple second limiting members can extend under the thrust of the inert gas. At this time, a limit can be formed between multiple first limiting members and multiple second limiting members, making the plug unable to be pulled out of the socket groove, quickly completing the repair and replacement work, avoiding expensive repair costs and downtime, reducing the time of subway service interruption, ensuring the travel needs of passengers, reducing traffic pressure, maintaining urban traffic order, and thus improving the overall operation efficiency.

[0021] 2. Through the arrangement of structures such as the first telescopic member and the second telescopic member in the present invention, when a fire occurs and the outer sheath is burned out, the inert gas in multiple sealing grooves will leak, no longer providing thrust for the first limiting member and the second limiting member. The inert gas in the first telescopic groove and the second telescopic groove will expand and push the first telescopic member and the second telescopic member, so that the first limiting member and the second limiting member move away from each other and no longer play a limiting role. The inert gas in the pushing groove will expand, and the plug whose limit is released will be pushed out of the socket groove through the pushing plate, thus completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, reducing the overall damage, minimizing the power outage range, ensuring the power supply in the non-fire area, reducing the overall impact of the fire on the subway system, thus reducing property losses and ensuring the safety of passengers.

[0022] 3. Through the arrangement of structures such as the first airbag, the second airbag and the support rod in the present invention, when a fire occurs and the outer sheath is burned out, the first airbag and the second airbag will burst. The inert gas ejected from the rupture of the first airbag and the second airbag will be sprayed between the plug and the socket groove, playing a pushing role, thus further accelerating the separation between the cables. At the same time, the gas ejected after the first airbag and the second airbag burst will be sprayed towards both ends of the adjacent cable bodies during separation, reducing the oxygen concentration in the fire area, thus inhibiting the spread of the flame, and being able to extinguish the fire at both ends of the adjacent cable bodies, further preventing the fire on the cable from spreading to the adjacent cable. Description of the drawings

[0023] Figure 1This is a cross-sectional view of the cable body structure of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of the first plug-in part of the present invention.

[0025] Figure 3 This is a schematic diagram of the structure of the second plug-in part of the present invention.

[0026] Figure 4 This is a schematic diagram of the structure of the outer sheath of the present invention.

[0027] Figure 5 This is a schematic diagram of the plug-in of the cable body of the present invention.

[0028] Figure 6 This is a cross-sectional view of the internal structure of the plug-in of the cable body of the present invention.

[0029] Figure 7 For the present invention Figure 6 Enlarged view of the structure of part A.

[0030] Figure 8 This is an exploded view of the partial structure of the first limiting member of the present invention.

[0031] Figure 9 This is an exploded view of the partial structure of the second limiting member of the present invention.

[0032] Figure 10 This is a cross-sectional view of the mating state of the first limiting member and the second limiting member of the present invention.

[0033] Figure 11 This is a schematic diagram of the first airbag of the present invention.

[0034] Figure 12 This is a cross-sectional view of the internal structure of the first airbag of the present invention.

[0035] Reference numerals are: 1, cable body; 11, cable core; 12, insulating layer; 13, flame-retardant filling layer; 14, flame-retardant layer; 15, outer sheath; 2, first plug-in part; 21, plug connector; 22, first limiting groove; 23, first limiting member; 24, first installation groove; 25, first airbag; 26, first sealing plate; 27, first telescopic groove; 28, first telescopic member; 29, male docking head; 3, second plug-in part; 31, plug-in slot; 32, second limiting groove; 33, second limiting member; 34, second installation groove; 35, second airbag; 36, second sealing plate; 37, second telescopic groove; 38, second telescopic member; 39, female docking head; 4, support rod; 5, sealing groove; 6, pushing groove; 61, pushing plate. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1

[0038] A severely burned cable cannot be restored through simple repair and needs to be repaired and replaced. The repair and replacement steps are relatively cumbersome, which will cause partial or complete suspension of the subway line operation, resulting in inconvenient transportation and increasing the burden on other means of transportation.

[0039] Reference Figure 1 And Figure 5 Referring to

[0040] Reference Figure 1 And Figure 5 Referring to

[0041] Reference Figures 7 - 10, on one side of the first limiting member 23 located inside the first limiting groove 22, a first sealing plate 26 is fixedly connected. The first sealing plate 26 is hermetically and slidably connected within the first limiting groove 22. On one side of the second limiting member 33 located inside the second limiting groove 32, a second sealing plate 36 is fixedly connected. The second sealing plate 36 is hermetically and slidably connected within the second limiting groove 32. Inside the outer sheath 15, sealing grooves 5 with the same number and corresponding positions as the plug connectors 21 are provided. Multiple sealing grooves 5 are all communicated with the interiors of the corresponding first limiting grooves 22 and the corresponding second limiting grooves 32. Each sealing groove 5 is filled with an inert gas. The two sides of the first limiting member 23 located outside the first limiting groove 22 and along the length direction of the cable body 1 are both provided as wedge-shaped surfaces. The two sides of the second limiting member 33 located outside the second limiting groove 32 and along the length direction of the cable body 1 are both provided as wedge-shaped surfaces.

[0042] Reference Figure 1 , Figure 2 and Figure 6 , between one end of each cable core 11 located inside the plug connector 21 and the corresponding insulating layer 12, a docking male head 29 is sleeved. Between one end of each cable core 11 located inside the docking slot 31 and the corresponding insulating layer 12, a docking female head 39 is sleeved. The docking male head 29 can be inserted into the docking female head 39 for electrical connection.

[0043] When the plug connector 21 is inserted into the interior of the docking slot 31, the plug connector 21 can cooperate with the wedge-shaped surface of the first limiting member 23, causing the first limiting member 23 to slide inside the first limiting groove 22. The docking slot 31 can cooperate with the wedge-shaped surface of the second limiting member 33, causing the second limiting member 33 to slide inside the second limiting groove 32.

[0044] When the plug connector 21 is completely inserted into the docking slot 31, each first limiting member 23 and the corresponding second limiting member 33 are arranged in an interleaved manner.

[0045] During specific use, when the cable is severely burned out and needs to be repaired and replaced, make the first docking portion 2 of one cable body 1 correspond to the second docking portion 3 of another cable body 1, insert the plug connector 21 into the docking slot 31, and insert multiple docking male heads 29 into the corresponding docking female heads 30.

[0046] Since the sealing groove 5 is filled with inert gas and multiple sealing grooves 5 are all internally communicated with the corresponding first limiting groove 22 and the corresponding second limiting groove 32, the first limiting member 23 and the second limiting member 33 are both in the extended state before insertion. During the process of the plug connector 21 being inserted into the insertion groove 31, the plug connector 21 can cooperate with the wedge surface of the first limiting member 23, causing the first limiting member 23 to slide inside the first limiting groove 22 and compressing the inert gas in the sealing groove 5 through the first sealing plate 26. The insertion groove 31 can cooperate with the wedge surface of the second limiting member 33, causing the second limiting member 33 to slide inside the second limiting groove 32 and compressing the inert gas in the sealing groove 5 through the second sealing plate 36, so that the plug connector 21 can be smoothly inserted into the insertion groove 31;

[0047] When the plug connector 21 is completely inserted into the insertion groove 31, referring to Figure 7 and Figure 10 , it will make the positions of multiple first limiting grooves 22 and multiple second limiting grooves 32 correspond, and make the multiple first limiting members 23 and the corresponding second limiting members 33 arranged in an alternating manner. At this time, the multiple first limiting members 23 and the multiple second limiting members 33 can extend under the thrust of the inert gas. At this time, a limit can be formed between the multiple first limiting members 23 and the multiple second limiting members 33, making the plug connector 21 unable to be pulled out of the insertion groove 31, thus quickly completing the repair and replacement work.

[0048] In summary, through the arrangement of structures such as the first limiting member 23 and the second limiting member 33, when the plug connector 21 is completely inserted into the insertion groove 31, it will make the positions of multiple first limiting grooves 22 and multiple second limiting grooves 32 correspond, and make the multiple first limiting members 23 and the corresponding second limiting members 33 arranged in an alternating manner. At this time, the multiple first limiting members 23 and the multiple second limiting members 33 can extend under the thrust of the inert gas. At this time, a limit can be formed between the multiple first limiting members 23 and the multiple second limiting members 33, making the plug connector 21 unable to be pulled out of the insertion groove 31, quickly completing the repair and replacement work, which can avoid expensive repair costs and downtime, reduce the time of subway service interruption, ensure the travel needs of passengers, relieve traffic pressure, maintain urban traffic order, and thus improve the overall operation efficiency.

[0049] Embodiment 2

[0050] During the actual use process, when a serious fire occurs in the cable, there will still be a phenomenon that the fire spreads to other non-damaged areas, which will expand the fire range, generate more smoke and flames, cause difficulties for passengers to evacuate, and increase the risk of casualties. Therefore, this embodiment improves the device described in the above embodiment.

[0051] Referring to Figures 7 - 10, on one side of the first limiting member 23 located outside the first limiting groove 22, a first telescopic groove 27 is provided. A first telescopic member 28 is hermetically and slidably connected in the first telescopic groove 27. On one side of the second limiting member 33 located outside the second limiting groove 32, a second telescopic groove 37 is provided. A second telescopic member 38 is hermetically and slidably connected in the second telescopic groove 37. The side of the first telescopic member 28 located outside the first telescopic groove 27 is set as an arc surface. The side of the second telescopic member 38 located outside the second telescopic groove 37 is set as an arc surface.

[0052] Reference Figure 8 At both ends of the flame retardant layer 14, push grooves 6 are provided. In both of the two push grooves 6, push plates 61 are hermetically and slidably connected. Inert gas is filled between each push groove 6 and the corresponding push plate 61. Inert gas is filled between each first telescopic groove 27 and the corresponding first telescopic member 28. Inert gas is filled between each second telescopic groove 37 and the corresponding second telescopic member 38. And the air pressure of the inert gas in each sealing groove 5 is greater than the gas of the expansion gas in the corresponding first telescopic groove 27 and the corresponding second telescopic groove 37.

[0053] When the plug connector 21 is inserted into the inside of the socket 31, the plug connector 21 can cooperate with the wedge surface of the first limiting member 23 and the arc surface of the first telescopic member 28 to make the first limiting member 23 slide inside the first limiting groove 22, so that the first telescopic member 28 slides inside the first telescopic groove 27. The socket 31 can cooperate with the wedge surface of the second limiting member 33 and the arc surface of the second telescopic member 38 to make the second limiting member 33 slide inside the second limiting groove 32, so that the second telescopic member 38 slides inside the second telescopic groove 37.

[0054] When the plug connector 21 is completely inserted into the socket 31, each first limiting member 23 and the corresponding second limiting member 33 are arranged in an interleaved manner. Each first telescopic member 28 can contact the surface of the corresponding second sealing plate 36. Each second telescopic member 38 can contact the surface of the corresponding first sealing plate 26.

[0055] During specific use, during the process of inserting the plug connector 21 into the socket 31, the plug connector 21 will first cooperate with the wedge surface of the first limiting member 23. The first telescopic member 28 will follow the first limiting member 23 and slide inside the first limiting groove 22, so that the plug connector 21 can cooperate with the arc surface of the first telescopic member 28 during further movement, thereby pushing the first telescopic member 28 to slide inside the first telescopic groove 27 and compressing the inert gas inside the first telescopic groove 27;

[0056] The insertion slot 31 will preferentially cooperate with the wedge surface of the second limiting member 33, and the second telescopic member 38 will follow the second limiting member 33 to slide inside the second limiting slot 32, so that the insertion slot 31 can cooperate with the arc surface of the second telescopic member 38 during further movement, thereby pushing the second telescopic member 38 to slide in the second telescopic slot 37 and compressing the inert gas in the second telescopic slot 37, so as not to affect the insertion of the plug connector 21 into the insertion slot 31.

[0057] When the plug connector 21 is completely inserted into the insertion slot 31, such that the multiple first limiting members 23 and the corresponding second limiting members 33 are arranged in an interleaved manner, the multiple first telescopic members 28 can contact the surface of the corresponding second sealing plate 36 under the thrust of the inert gas in the corresponding first telescopic slot 27, and the multiple second telescopic members 38 can contact the surface of the corresponding first sealing plate 26 under the thrust of the inert gas in the second telescopic slot 37. Since the air pressure of the inert gas in the multiple sealing slots 5 is greater than the air pressure of the inert gas in the corresponding first telescopic slot 27 and the corresponding second telescopic slot 37, at this time, the first telescopic member 28 and the second telescopic member 38 cannot push the corresponding first limiting member 23 and the corresponding second limiting member 33 away from each other, cannot release the limitation between the first limiting member 23 and the second limiting member 33, and will not affect the docking between the cables.

[0058] Meanwhile, during the process of inserting the plug connector 21 into the insertion slot 31, the positions of the two pushing slots 6 will correspond, the two pushing plates 61 will squeeze each other, such that the two pushing plates 61 slide in the corresponding pushing slots 6 and compress the inert gas in the corresponding pushing slots 6.

[0059] When a fire occurs and the outer sheath 15 is burned out, the inert gas in the multiple sealing slots 5 will expand and leak. The leaked inert gas can play a role in extinguishing the fire and reducing the spread of the fire. After the inert gas leaks, the pressure in the first limiting slot 22 and the second limiting slot 32 will disappear, and no longer provide thrust for the first limiting member 23 and the second limiting member 33. At this time, the inert gas in the first telescopic slot 27 and the second telescopic slot 37 will expand and push the first telescopic member 28 and the second telescopic member 38 back to their initial positions. At the same time, the first telescopic member 28 and the second telescopic member 38 will push the first limiting member 23 and the second limiting member 33 away from each other. At this time, the wedges on the side where the first limiting member 23 and the second limiting member 33 are close to each other can cooperate, and the first limiting member 23 and the second limiting member 33 no longer play a limiting role.

[0060] Meanwhile, the inert gas in the pushing slots 6 will expand, thereby causing the pushing plates 61 to extend, thereby pushing the plug connector 21 whose limitation has been released out of the insertion slot 31, thereby completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, and reducing the overall damage.

[0061] In summary, through the arrangement of structures such as the first telescopic member 28 and the second telescopic member 38, when a fire occurs and the outer sheath 15 is burned out, the inert gas in the plurality of sealing grooves 5 will leak, and no longer provide thrust for the first limiting member 23 and the second limiting member 33. The inert gas in the first telescopic groove 27 and the second telescopic groove 37 will expand and push the first telescopic member 28 and the second telescopic member 38, so that the first limiting member 23 and the second limiting member 33 move away from each other and no longer play a limiting role. The inert gas in the pushing groove 6 will expand, and the plug connector 21 that has been released from the limit will be pushed out of the plugging groove 31 through the pushing plate 61, thereby completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, reducing the overall damage, minimizing the power outage range, ensuring the power supply in the non-fire area, reducing the overall impact of the fire on the subway system, thereby reducing property losses and ensuring the safety of passengers.

[0062] Embodiment 3

[0063] In order to further reduce the spread of fire, accelerate the separation between cables, and improve the flame retardant and fire resistance effects.

[0064] Reference Figure 4 、 Figure 7 、 Figure 11 and Figure 12 On the outer peripheral side of the plug connector 21, a first installation groove 24 is provided. On the inner peripheral side of the plugging groove 31, a second installation groove 34 is provided. A first airbag 25 is embedded in the first installation groove 24, and a second airbag 35 is embedded in the second installation groove 34. A plurality of support rods 4 are fixedly connected to the inner walls of the first airbag 25 and the second airbag 35 and are equally spaced. The plurality of sealing grooves 5 are all communicated with the first airbag 25 and the second airbag 35. When the plug connector 21 of one cable body 1 is completely inserted into the plugging groove 31 of another cable body 1, the positions of the first installation groove 24 and the second installation groove 34 correspond to each other, and a seal can be formed between the first airbag 25 and the second airbag 35.

[0065] During actual use, when the plug connector 21 is completely inserted into the plugging groove 31, the first installation groove 24 will correspond to the second installation groove 34 in position, and the first airbag 25 and the second airbag 35 can expand and form a seal under the action of the inert gas in the plurality of sealing grooves 5, thereby preventing moisture from entering the cable interior, avoiding a decrease in insulation performance and electrical faults caused by moisture, and at the same time protecting the cable from chemical corrosion and extending the service life of the cable.

[0066] When a fire occurs and the outer sheath 15 is burned out, the inert gas in the multiple sealing grooves 5 will first expand. The expanded inert gas will enter the first airbag 25 and the second airbag 35, causing the first airbag 25 and the second airbag 35 to further expand violently. This will cause a tear between the inner surfaces of the first airbag 25 and the second airbag 35 and the support rod 4, resulting in the rupture of the first airbag 25 and the second airbag 35. At this time, the inert gas in the first airbag 25 and the second airbag 35 will be ejected from the rupture.

[0067] When the outer sheath 15 is burned out and the inert gas in the multiple sealing grooves 5 leaks, causing the first limiting member 23 and the second limiting member 33 to no longer play a limiting role, the inert gas ejected from the rupture of the first airbag 25 and the second airbag 35 will be ejected between the plug connector 21 and the socket groove 31, playing a pushing role, thereby further accelerating the separation between the cables.

[0068] At the same time, the gas ejected after the rupture of the first airbag 25 and the second airbag 35 will be ejected towards both ends of the adjacent cable body 1 during separation, so as to extinguish the fire at both ends of the adjacent cable body 1 and further prevent the fire on the cable from spreading to the adjacent cable.

[0069] In summary, through the arrangement of structures such as the first airbag 25, the second airbag 35, and the support rod 4, when a fire occurs and the outer sheath 15 is burned out, the first airbag 25 and the second airbag 35 will rupture. The inert gas ejected from the rupture of the first airbag 25 and the second airbag 35 will be ejected between the plug connector 21 and the socket groove 31, playing a pushing role, thereby further accelerating the separation between the cables. At the same time, the gas ejected after the rupture of the first airbag 25 and the second airbag 35 will be ejected towards both ends of the adjacent cable body 1 during separation, reducing the oxygen concentration in the fire area, thereby inhibiting the spread of the flame, so as to extinguish the fire at both ends of the adjacent cable body 1 and further prevent the fire on the cable from spreading to the adjacent cable.

[0070] Finally: The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A flame-retardant B1-class fire-resistant cable for subway use, comprising a cable body (1), characterized in that: The cable body (1) includes a cable core (11), and a plurality of the cable cores (11) are provided. A layer of insulating layer (12) is wrapped outside each of the plurality of cable cores (11). A flame-retardant filling layer (13) is wrapped outside the plurality of insulating layers (12). A flame-retardant layer (14) is wrapped outside the flame-retardant filling layer (13). An outer sheath (15) is wrapped outside the flame-retardant layer (14). A first plug-in part (2) and a second plug-in part (3) are respectively arranged at both ends of the cable body (1). Adjacent two cable bodies (1) can be butted; The first plug-in part (2) includes a plug connector (21) opened at one end of the outer sheath (15). The second plug-in part (3) includes a plug-in slot (31) opened at the other end of the outer sheath (15) away from the plug connector (21). A plurality of first limiting slots (22) are equidistantly opened on the outer peripheral side of the plug connector (21). A plurality of second limiting slots (32) with the same number as the first limiting slots (22) are equidistantly opened on the inner peripheral side of the plug-in slot (31). A first limiting member (23) is arranged in each of the first limiting slots (22). A second limiting member (33) is arranged in each of the second limiting slots (32). When the plug connector (21) of one of the cable bodies (1) is completely inserted into the plug-in slot (31) of the other cable body (1), the positions of the plurality of first limiting slots (22) and the plurality of second limiting slots (32) correspond to each other, and the plurality of first limiting members (23) and the plurality of second limiting members (33) can extend out for limiting; A first telescopic slot (27) is opened on one side of the first limiting member (23) located outside the first limiting slot (22). A first telescopic member (28) is hermetically and slidably connected in the first telescopic slot (27). A second telescopic slot (37) is opened on one side of the second limiting member (33) located outside the second limiting slot (32). A second telescopic member (38) is hermetically and slidably connected in the second telescopic slot (37). Both sides of the first limiting member (23) located outside the first limiting slot (22) and along the length direction of the cable body (1) are provided as wedge-shaped surfaces. Both sides of the second limiting member (33) located outside the second limiting slot (32) and along the length direction of the cable body (1) are provided as wedge-shaped surfaces. One side of the first telescopic member (28) located outside the first telescopic slot (27) is provided as an arc surface. One side of the second telescopic member (38) located outside the second telescopic slot (37) is provided as an arc surface; When the plug connector (21) is inserted into the interior of the socket (31), the plug connector (21) can cooperate with the wedge-shaped surface of the first limiting member (23) and the arc surface of the first telescopic member (28) so that the first limiting member (23) slides inside the first limiting groove (22), and the first telescopic member (28) slides inside the first telescopic groove (27). The socket (31) can cooperate with the wedge-shaped surface of the second limiting member (33) and the arc surface of the second telescopic member (38) so that the second limiting member (33) slides inside the second limiting groove (32), and the second telescopic member (38) slides inside the second telescopic groove (37).

2. The flame-retardant B1-class special fire-resistant cable for subways according to claim 1, characterized in that: A first mounting groove (24) is formed on the outer peripheral side of the plug connector (21), and a second mounting groove (34) is formed on the inner peripheral side of the socket (31). A first airbag (25) is embedded in the first mounting groove (24), and a second airbag (35) is embedded in the second mounting groove (34). A plurality of support rods (4) are fixedly connected to the inner walls of the first airbag (25) and the second airbag (35) and are equally spaced. When the plug connector (21) of one cable body (1) is completely inserted into the socket (31) of another cable body (1), the positions of the first mounting groove (24) and the second mounting groove (34) correspond to each other, and a seal can be formed between the first airbag (25) and the second airbag (35).

3. The flame-retardant B1-class special fire-resistant cable for subways according to claim 2, wherein: A first sealing plate (26) is fixedly connected to one side of the first limiting member (23) located inside the first limiting groove (22), and the first sealing plate (26) is sealingly slidably connected inside the first limiting groove (22). A second sealing plate (36) is fixedly connected to one side of the second limiting member (33) located inside the second limiting groove (32), and the second sealing plate (36) is sealingly slidably connected inside the second limiting groove (32).

4. The flame-retardant B1-grade subway special fire-resistant cable according to claim 3, wherein: Sealing grooves (5) with the same number and corresponding positions as the plug connectors (21) are formed inside the outer sheath (15). The plurality of sealing grooves (5) are all communicated with the interiors of the corresponding first limiting grooves (22) and the corresponding second limiting grooves (32), and the plurality of sealing grooves (5) are all communicated with the first airbag (25) and the second airbag (35).

5. The flame-retardant B1-class special fire-resistant cable for subways according to claim 4, characterized in that: Both ends of the flame retardant layer (14) are provided with pushing grooves (6), and pushing plates (61) are hermetically and slidably connected in the two pushing grooves (6). Inert gas is filled between each pushing groove (6) and the corresponding pushing plate (61). Inert gas is filled in each sealing groove (5). Inert gas is filled between each first telescopic groove (27) and the corresponding first telescopic member (28). Inert gas is filled between each second telescopic groove (37) and the corresponding second telescopic member (38). And the air pressure of the inert gas in each sealing groove (5) is greater than the gas pressure of the expansion gas in the corresponding first telescopic groove (27) and the corresponding second telescopic groove (37).

6. The flame-retardant B1-grade subway special fire-resistant cable according to claim 5, wherein: When the plug connector (21) is completely inserted into the socket (31), each first limiting member (23) and the corresponding second limiting member (33) are arranged in an interleaved manner. Each first telescopic member (28) can contact the surface of the corresponding second sealing plate (36). Each second telescopic member (38) can contact the surface of the corresponding first sealing plate (26).

7. The flame-retardant B1-grade special fire-resistant cable for subways according to claim 6, characterized in that: A docking male head (29) is sleeved between one end of each cable core (11) inside the plug connector (21) and the corresponding insulating layer (12). A docking female head (39) is sleeved between one end of each cable core (11) inside the socket (31) and the corresponding insulating layer (12). The docking male head (29) can be inserted into the docking female head (39) for electrical connection.

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