A kind of mine-used central tube filled flame-retardant polyvinyl chloride sheathed communication optical cable

Abstract

The present invention discloses a mine-used central tube filled flame-retardant polyvinyl chloride sheathed communication optical cable, belonging to the technical field of mine-used communication optical cables. It includes a flame-retardant polyethylene sheath, and a plurality of card slots are equidistantly arranged in the flame-retardant polyethylene sheath. Multiple groups of optical fiber anti-fracture mechanisms are arranged at positions corresponding to the card slots in the flame-retardant polyethylene sheath. By setting the optical fiber anti-fracture mechanism, the present invention uses a composite braided wire made of fluorocarbon wire and nylon wire to replace parallel steel wires, avoiding the risk of frictional sparks brought by the metal structure. The spiral directions of the six loose tubes in the present invention change periodically. Compared with the structure with a single spiral direction, the optical cable can evenly bear the external stress in different directions, which helps to prevent excessive stretching or compression in a specific direction, thereby reducing the risk of optical fiber damage and meeting the extremely complex use environment in mines.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine communication optical cables, and particularly relates to a mine central tube filled flame-retardant polyvinyl chloride sheath communication optical cable. Background Art

[0002] The mine central tube filled flame-retardant polyvinyl chloride sheath communication optical cable is a professional optical cable specifically designed to meet the communication needs in special environments such as coal mines. In these environments, safety and reliability are crucial considerations because there are flammable gases and dust in the coal mine underground. Once a fire breaks out, the consequences will be unimaginable. Therefore, this kind of optical cable adopts special materials and technologies to improve its fire resistance performance, ensuring that even under extreme conditions, the fire risk can be effectively reduced and the stable operation of the communication system can be guaranteed.

[0003] Compared with ordinary communication optical cables, the most easily overlooked and main point of mine communication optical cables is fire prevention and explosion prevention. Communication optical cables mainly adopt central tube type or stranded type optical cables according to the number of fiber cores. Both the central tube type optical cable and the stranded type optical cable contain steel strips. The polyethylene sheath in the central tube type optical cable also contains two parallel steel wires, and the stranded type optical cable contains a central strengthening member, which is generally made of metal material. Whether it is a central tube type or a stranded type optical cable, the conventional specifications cannot meet the mine use conditions. Mine optical cables should meet the non-metallic structure design to avoid frictional sparks and meet the Ex ia I class explosion-proof certification. Obviously, the conventional optical cable design does not meet the requirements;

[0004] In addition, in conventional optical cables, the multi-strand loose tubes in the optical cable basically adopt a spiral stranding structure. This structure can improve flexibility and fatigue resistance, reduce mechanical damage to the optical cable, and because the optical fibers under the spiral stranding structure have enough slack compared with the straight-line structure, the spiral structure can naturally form a "relaxed" path for the optical fibers, ensuring that the optical fibers have enough margin to buffer when the optical cable is bent or stretched, avoiding excessive stretching or breakage. However, the problem is that the mine use conditions are more complex, and the maintenance and replacement cycles of the existing spiral stranding structure optical cables are relatively short. Summary of the Invention

[0005] In order to overcome the above defects, the present invention provides a mine central tube filled flame-retardant polyvinyl chloride sheath communication optical cable, which solves the problems in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solution: A mine central tube filled flame-retardant polyvinyl chloride sheath communication optical cable, comprising:

[0007] Flame-retardant polyethylene sheath, in which a plurality of card slots are equidistantly arranged. Corresponding to the positions of the card slots in the flame-retardant polyethylene sheath, multiple groups of optical fiber anti-breakage mechanisms are arranged. Six loose tubes are movably connected in the flame-retardant polyethylene sheath. Optical fibers are filled in the loose tubes. The six loose tubes are spirally distributed. The six loose tubes are slidably connected in the optical fiber anti-breakage mechanism. The spiral directions of the six loose tubes on both sides of each group of optical fiber anti-breakage mechanisms are opposite;

[0008] The optical fiber anti-breakage mechanism includes two sheath guiding and clamping sleeves fixedly connected in the flame-retardant polyethylene sheath. Limiting blocks are fixedly connected to the outer walls of the sheath guiding and clamping sleeves. The limiting blocks are movably connected in the corresponding card slots on one side. An activity groove is opened on the sheath guiding and clamping sleeve. Six triangular clamping plates are fixedly connected in the activity groove. Guide holes are opened on the triangular clamping plates. The loose tubes are slidably connected in the guide holes. A positioning block is fixedly connected between the six triangular clamping plates. A wire splitting cone is fixedly connected to the axial center position of the positioning block. A torsion outer shell is rotatably connected between the two sheath guiding and clamping sleeves. A torsion circular plate is fixedly connected in the torsion outer shell. Six torsion hole positions are opened on the torsion circular plate. Six first connecting plates are fixedly connected to the mutually approaching sides of the two corresponding sheath guiding and clamping sleeves on one side. Six second connecting plates are fixedly connected to the inner wall of the torsion outer shell. A cylindrical tension spring is fixedly connected between the first connecting plate and the corresponding second connecting plate on one side.

[0009] As a further solution of the present invention: Two wire threading seats are fixedly connected to the outer wall of the sheath guiding and clamping sleeve.

[0010] As a further solution of the present invention: Four fixed anchor points are arranged outside the torsion outer shell. A composite braided wire is fixedly connected between the corresponding fixed anchor points between adjacent torsion outer shells. The composite braided wire passes through the corresponding wire threading seat on one side.

[0011] As a further solution of the present invention: The composite braided wire is woven from fluorocarbon wire and nylon wire.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] First of all, by setting the optical fiber anti-breakage mechanism, the present invention uses a composite braided wire woven from fluorocarbon wire and nylon wire to replace parallel steel wires, avoiding the risk of frictional sparks brought by metal structures. This composite braided wire has certain ductility, wear resistance, is not easy to break, and has strong rigidity. The fluorocarbon wire does not absorb water and is resistant to chemical corrosion, suitable for long-term use. Moreover, the fluorocarbon wire has a high density and strong rigidity, which can provide structural support. However, the fluorocarbon wire has poor ductility, and the nylon wire has insufficient wear resistance. The two complement each other, making the composite braided wire not only have the advantages of the fluorocarbon wire but also make up for the defect of insufficient ductility of the fluorocarbon wire;

[0014] Secondly, the periodic change in the spiral direction of the six loose tubes in the present invention, compared with the structure of a single spiral direction, can make the optical cable evenly bear the external stress applied in different directions. This approach helps to prevent excessive stretching or compression in a specific direction, thereby reducing the risk of optical fiber damage and meeting the extremely complex use environment in mines. Changing the spiral direction also helps to balance the torsional force generated inside the optical cable. When the optical cable is twisted, the spirals in different directions can offset part of the torsional stress of each other, reduce the probability of optical fiber damage caused by twisting, and improve the overall mechanical stability. In addition, for application scenarios that require high bandwidth and long-distance transmission, reducing polarization mode dispersion is an important consideration. By changing the spiral direction, the linear effect that may cause polarization mode dispersion can be disrupted, thereby improving signal quality;

[0015] Finally, when the optical cable is subjected to external impact, the flame-retardant polyethylene sheath is deformed, and the composite braided wire is also impacted, which will drive the torsion shells on both sides to rotate, thereby stretching the cylindrical tension spring. Since the periodic change of the spiral direction of the loose tube is mainly due to the misalignment of the torsion shell and the sheath guide sleeves on both sides, the passive rotation of the torsion shell can make the loose tube in the spiral state reversely twisted to partially release the spiral structure, thereby actively releasing the excess length of the optical fiber. The active reverse twisting mechanism can adjust the state of the optical fiber according to actual conditions to ensure that it can maintain appropriate slack under different conditions, thereby improving the overall adaptability and flexibility of the optical cable, and also helping to more evenly distribute the stress applied to the optical fiber. Under the traditional fixed spiral structure, the optical fiber may be subjected to uneven tension or pressure at some points, and the dynamic adjustment achieved through the mechanical structure can help disperse these stresses, reduce local stress concentration, and reduce the risk of optical fiber damage due to excessive stretching or compression. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0017] Figure 2 It is a schematic diagram of the three-dimensional internal structure of the present invention;

[0018] Figure 3 It is a front view structural schematic diagram of the loose tube part of the present invention;

[0019] Figure 4 It is a schematic diagram of the three-dimensional structure of the sheath guide sleeve of the present invention;

[0020] Figure 5 It is a three-dimensional structural schematic diagram of the sheath guide sleeve of the present invention from another angle;

[0021] Figure 6 It is a schematic diagram of the three-dimensional structure of the torsion housing of the present invention.

[0022] In the figure: 1 Flame-retardant polyethylene sheath, 2 Loose tube, 3 Sheath guide ferrule, 4 Limit block, 5 Movable groove, 6 Triangular clamping plate, 7 Guide hole, 8 Composite braided wire, 9 Positioning block, 10 Fiber splitting cone, 11 Twisting housing, 12 Twisting circular plate, 13 Twisting hole position, 14 First connecting plate, 15 Second connecting plate, 16 Cylindrical tension spring, 17 Wire threading base, 18 Fixed anchor point. Specific embodiments

[0023] The technical solutions of this patent will be further described in detail below in conjunction with specific embodiments.

[0024] As Figures 1-6 shown, the present invention provides a technical solution:

[0025] A mine-used central tube filled flame-retardant polyvinyl chloride sheath communication optical cable, comprising:

[0026] A flame-retardant polyethylene sheath 1, in which a plurality of card slots are equidistantly arranged, and a plurality of groups of optical fiber anti-fracture mechanisms are arranged at positions corresponding to the card slots in the flame-retardant polyethylene sheath 1. Six loose tubes 2 are movably connected in the flame-retardant polyethylene sheath 1. Optical fibers are filled in the loose tubes 2. The six loose tubes 2 are spirally distributed. The six loose tubes 2 are slidably connected in the optical fiber anti-fracture mechanism. The spiral directions of the six loose tubes 2 on both sides of each group of optical fiber anti-fracture mechanisms are opposite. The flame-retardant polyethylene sheath 1 is made of flame-retardant PVC material, which has good flame retardancy, wear resistance and corrosion resistance, and is suitable for flammable and explosive environments such as mines. In the present invention, the spiral directions of the six loose tubes 2 change periodically. Compared with the structure with a single spiral direction, the optical cable can evenly bear the external stress in different directions. This approach helps to prevent excessive stretching or compression in a specific direction, thereby reducing the risk of optical fiber damage and meeting the extremely complex usage environment in the mine. Changing the spiral direction also helps to balance the torsional force generated inside the optical cable. When the optical cable is twisted, the spirals in different directions can cancel out part of the torsional stress, reducing the probability of optical fiber damage caused by torsion and improving the overall mechanical stability. In addition, for application scenarios that require high bandwidth and long-distance transmission, reducing polarization mode dispersion is an important consideration. By changing the spiral direction, the linear effects that may cause polarization mode dispersion can be disrupted, thereby improving the signal quality;

[0027] The optical fiber anti - fracture mechanism includes two sheath guiding bushings 3 fixedly connected inside the flame - retardant polyethylene sheath 1. A limiting block 4 is fixedly connected to the outer wall of the sheath guiding bushing 3, and the limiting block 4 is movably connected to the corresponding slot on one side. An activity groove 5 is opened on the sheath guiding bushing 3, and six triangular clamping plates 6 are fixedly connected inside the activity groove 5. A guiding hole 7 is opened on the triangular clamping plate 6, and the loose tube 2 is slidably connected inside the guiding hole 7. A positioning block 9 is fixedly connected between the six triangular clamping plates 6, and a wire - dividing cone 10 is fixedly connected to the axial center position of the positioning block 9. A torsion outer shell 11 is rotatably connected between the two sheath guiding bushings 3. A torsion circular plate 12 is fixedly connected inside the torsion outer shell 11, and six torsion hole positions 13 are opened on the torsion circular plate 12. Six first connecting plates 14 are fixedly connected to the mutually - approaching sides of the two corresponding sheath guiding bushings 3 on one side. Six second connecting plates 15 are fixedly connected to the inner wall of the torsion outer shell 11. A cylindrical tension spring 16 is fixedly connected between the first connecting plate 14 and the corresponding second connecting plate 15 on one side. Two wire - passing seats 17 are fixedly connected to the outer wall of the sheath guiding bushing 3. Four fixed anchor points 18 are arranged outside the torsion outer shell 11. A composite braided wire 8 is fixedly connected between the corresponding fixed anchor points 18 between adjacent two torsion outer shells 11. The composite braided wire 8 passes through the corresponding wire - passing seat 17 on one side. The composite braided wire 8 is woven from fluorocarbon - containing wire and nylon wire. The periodic spiral structure of the optical fibers in the six loose tubes 2 results from the misalignment of the torsion outer shell 11 and the sheath guiding bushings 3 on its two sides. When the optical cable is subjected to external impact, the flame - retardant polyethylene sheath 1 deforms, and the impact on the composite braided wire 8 will also drive the torsion outer shells 11 on its two sides to rotate, thereby stretching the cylindrical tension spring 16. At this time, the passive rotation of the torsion outer shell 11 can cause the loose tube 2 in the spiral state to be twisted in the reverse direction to partially relieve the spiral structure, so as to actively release the surplus length of the optical fiber. The active reverse - twisting mechanism can adjust the state of the optical fiber according to the actual situation to ensure that it can maintain an appropriate degree of slack under different conditions, thereby enhancing the overall adaptability and flexibility of the optical cable, and also helping to more evenly distribute the stress applied to the optical fiber. Under the traditional fixed spiral structure, the optical fiber may bear uneven tensile or compressive forces at some points, while the dynamic adjustment achieved through the mechanical structure can help disperse these stresses, reduce the phenomenon of local stress concentration, and reduce the risk of optical fiber damage caused by excessive stretching or compression;

[0028] The present invention uses a composite braided wire 8 woven from fluorocarbon - containing wire and nylon wire to replace the parallel steel wires, avoiding the risk of frictional sparks brought by the metal structure. This composite braided wire 8 has certain ductility, wear - resistance, is not easy to break, and has strong rigidity. The fluorocarbon - containing wire does not absorb water and is resistant to chemical corrosion, suitable for long - term use, and the fluorocarbon - containing wire has a high density and strong rigidity, which can provide structural support. However, the fluorocarbon - containing wire has poor ductility, and the nylon wire has insufficient wear - resistance. The two complement each other, making the composite braided wire 8 not only have the advantages of the fluorocarbon - containing wire but also make up for the defect of insufficient ductility of the fluorocarbon - containing wire.

[0029] The working principle of the present invention is as follows:

[0030] The flame-retardant polyethylene sheath 1 is made of flame-retardant PVC material, which has good flame retardancy, abrasion resistance and corrosion resistance, and is suitable for flammable and explosive environments such as mines. In the present invention, the spiral directions of the six loose tubes 2 are periodically changed. Compared with the structure with a single spiral direction, the optical cable can evenly bear the external stress in different directions. This approach helps to prevent excessive stretching or compression in a specific direction, thereby reducing the risk of optical fiber damage and meeting the extremely complex usage environment in mines. Changing the spiral direction also helps to balance the torsional force generated inside the optical cable. When the optical cable is twisted, the spirals in different directions can cancel out part of the torsional stress, reducing the probability of optical fiber damage caused by twisting and improving the overall mechanical stability. In addition, for application scenarios that require high bandwidth and long-distance transmission, reducing polarization mode dispersion is an important consideration. By changing the spiral direction, the linear effects that may cause polarization mode dispersion can be disrupted, thereby improving the signal quality;

[0031] The periodic spiral structure of the optical fibers in the six loose tubes 2 results from the misalignment of the torsion outer shell 11 and the sheath guiding bushings 3 on both sides thereof. When the optical cable is subjected to an external impact, the flame-retardant polyethylene sheath 1 deforms, and the composite braided wire 8 being impacted will also drive the torsion outer shell 11 on both sides to rotate, thereby stretching the cylindrical tension spring 16. At this time, the passive rotation of the torsion outer shell 11 can cause the loose tube 2 in the spiral state to twist in the reverse direction to partially release the spiral structure, thereby actively releasing the extra length of the optical fiber. The active reverse-twisting mechanism can adjust the state of the optical fiber according to the actual situation to ensure that it maintains an appropriate degree of slack under different conditions, thereby enhancing the overall adaptability and flexibility of the optical cable, and also helping to more evenly distribute the stress applied to the optical fiber. Under the traditional fixed spiral structure, the optical fiber may bear uneven tension or pressure at certain points, while the dynamic adjustment achieved through the mechanical structure can help to disperse these stresses, reduce the phenomenon of local stress concentration, and reduce the risk of optical fiber damage caused by excessive stretching or compression;

[0032] The present invention uses a composite braided wire 8 made of fluorocarbon wire and nylon wire to replace the parallel steel wire, avoiding the risk of frictional sparks brought by the metal structure. This composite braided wire 8 has certain ductility, abrasion resistance, is not easy to break, and has strong rigidity. The fluorocarbon wire does not absorb water and is resistant to chemical corrosion, suitable for long-term use, and the fluorocarbon wire has a high density and strong rigidity, which can provide structural support. However, the fluorocarbon wire has poor ductility, and the nylon wire has insufficient abrasion resistance. The two complement each other, making the composite braided wire 8 not only have the advantages of the fluorocarbon wire but also make up for the defect of the insufficient ductility of the fluorocarbon wire.

[0033] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A central tube filled flame retardant polyvinyl chloride sheathed communication optical cable for mining, characterized in that: include: A flame-retardant polyethylene sheath (1), wherein a plurality of slots are equidistantly provided in the flame-retardant polyethylene sheath (1), a plurality of groups of optical fiber anti-fracture mechanisms are provided in the flame-retardant polyethylene sheath (1) at positions corresponding to the slots, six loose tubes (2) are movably connected in the flame-retardant polyethylene sheath (1), the loose tubes (2) are filled with optical fibers, the six loose tubes (2) are distributed in a spiral shape, the six loose tubes (2) are slidably connected in the optical fiber anti-fracture mechanism, and the spiral directions of the six loose tubes (2) on both sides of each group of optical fiber anti-fracture mechanisms are opposite; The optical fiber anti-fracture mechanism comprises two sheath guide ferrules (3) fixedly connected to the flame-retardant polyethylene sheath (1); a limit block (4) is fixedly connected to the outer wall of the sheath guide ferrule (3); the limit block (4) is movably connected to a slot on a corresponding side; a movable slot (5) is provided on the sheath guide ferrule (3); six triangular clamping plates (6) are fixedly connected to the movable slot (5); a guide hole (7) is provided on the triangular clamping plate (6); the loose tube (2) is slidably connected to the guide hole (7); positioning blocks (9) are fixedly connected between the six triangular clamping plates (6); the positioning blocks (9) are axially connected to the guide hole (7); A dividing cone (10) is fixedly connected at the center position, a torsion shell (11) is rotatably connected between the two sleeve guide sleeves (3), a torsion circular plate (12) is fixedly connected inside the torsion shell (11), six torsion holes (13) are opened on the torsion circular plate (12), six No. 1 connecting plates (14) are fixedly connected to the side of the two sleeve guide sleeves (3) on the corresponding side close to each other, six No. 2 connecting plates (15) are fixedly connected to the inner wall of the torsion shell (11), and a cylindrical tension spring (16) is fixedly connected between the No. 1 connecting plate (14) and the No. 2 connecting plate (15) on the corresponding side.

2. The central tube filled flame retardant polyvinyl chloride sheathed communication optical cable for mining use according to claim 1, characterized in that: Two threading seats (17) are fixedly connected to the outer wall of the sheath guide sleeve (3).

3. The central tube filled flame retardant polyvinyl chloride sheathed communication optical cable for mining use according to claim 2, characterized in that: Four fixed anchor points (18) are arranged outside the torsion housing (11), and a composite braided wire (8) is fixedly connected between the corresponding fixed anchor points (18) between two adjacent torsion housings (11), and the composite braided wire (8) passes through the threading seat (17) on the corresponding side.

4. The central tube filled flame retardant polyvinyl chloride sheathed communication optical cable for mining use according to claim 3, characterized in that: The composite braided wire (8) is braided with fluorine-containing carbon wire and nylon wire.

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