A method for using an optical cable joint box for an optical fiber composite submarine cable repair joint

Abstract

This invention discloses a method for using an optical cable splice box for emergency repair of fiber optic composite submarine cables. The splice box comprises a main body module and an optical cable sealing and fixing module. First, the optical cable is stripped in layers according to specified dimensions to create a stepped interface. Then, the optical cable sealing and fixing module is assembled. The assembled module is screwed into the module fixing hole on the side of the splice box, and the stainless steel tube layer of the optical cable is fixed to the optical fiber fixing seat. A grounding wire is then pressed in, and the optical fiber is fused together. After fusion splicing, the optical fiber is coiled in a fusion coil. After coiling, the splice box cover and body are closed, and the external screws are tightened sequentially to complete the installation. This invention uses a modular design, has excellent water-blocking and tensile strength, and offers advantages such as wide adaptability, simple operation, and reliable performance.

Description

Technical Field

[0001] This invention relates to a method of using an optical fiber composite submarine cable repair joint cassette. Background Technology

[0002] Most of the optical cables in fiber optic composite submarine cables are lightweight submarine optical cables. In the fabrication of emergency repair joints for fiber optic composite submarine cables, the optical cable splice box becomes an indispensable core component. A reliable optical cable splice box can ensure that the emergency repair joint operates stably and reliably in the harsh underwater environment, ensuring the continuity and accuracy of data transmission.

[0003] Traditional fiber optic junction boxes are prone to sealing failure. They typically use a single-layer sealing structure, relying solely on a single O-ring rubber seal. Under prolonged exposure to the high pressure, high salinity, and complex marine environment of the deep sea, the seal can easily fail due to corrosion, aging, and deformation under high pressure. This can lead to seawater leakage, causing moisture to seep into the internal fiber optic connection points and affecting optical signal transmission.

[0004] Existing fiber optic splice boxes lack bending restraint devices at the sealed and fixed ends of the fiber optic cable, and only have a single-layer water-blocking gasket. After the fiber optic cable is bent excessively, the high pressure causes the fiber optic cable structure to break, allowing seawater to seep into the fiber optic splice box.

[0005] Existing traditional fiber optic splice boxes suffer from the problem of splice breakage. Traditional splice boxes use simple mechanical fixation to secure the fiber optic cable, which cannot effectively distribute and withstand external forces, making it easy for the splice to break and cause communication interruption.

[0006] Existing fiber optic junction box designs are mostly integrated structures, which cannot connect to fiber optic cables of different specifications, resulting in poor applicability; it is also difficult to quickly replace or upgrade components (such as fiber optic units or sealing modules) according to emergency repair needs.

[0007] In summary, the various shortcomings and defects of existing junction boxes make them prone to failure during use. When a submarine optical cable junction box fails, repair and replacement are relatively complex, and specialized equipment and technicians are required, significantly increasing operating costs. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a method for using an optical fiber composite submarine cable repair joint cassette.

[0009] To achieve the above objectives, the core solution of this invention is: A method of using an optical cable splice box for emergency repair of optical fiber composite submarine cable, wherein the optical cable splice box has a main module of optical cable splice box and an optical cable sealing and fixing module. The main module of the optical cable junction box includes an optical cable junction box body and an optical cable junction box cover. The optical cable junction box body has a fiber fusion splice tray, and module fixing holes are opened on the wall of the optical cable junction box body. An optical fiber fixing seat is also installed inside the optical cable junction box body. The optical fiber fixing seat is located between the fiber fusion splice tray and the module fixing holes. A seat cover is installed on the optical fiber fixing seat. The grounding wire is crimped to the optical fiber fixing seat with the help of the seat cover and the crimped copper terminal. A double-layer sealing ring with alternating inner and outer layers is set at the junction of the optical cable junction box cover and the optical cable junction box body. The optical cable sealing and fixing module includes a cover plate, a fixing nut, a clamping sleeve, a double-ended external threaded connector, a tapered angle pressure ring, a connecting nut, and a bending limit protection device. The fixing nut, clamping sleeve, double-ended external threaded connector, tapered angle pressure ring, connecting nut, and bending limit protection device form a central optical cable perforation hole. One end of the double-ended external threaded connector is connected to the inner end of the fixing nut via an external thread, and the other end is connected to the outer end of the connecting nut via an external thread. A tapered hole is formed in the middle of the double-ended external threaded connector, and the tapered angle pressure ring is installed in the tapered hole. The conical angle compression ring has a compression space; two compression sleeves are installed in the double-ended external threaded connector, with the installation positions at both ends of the conical angle compression ring; water-blocking washers and compression washers are installed between the compression sleeves and the conical angle compression ring, and a bending limit protection device is installed on the outer end of the fixing nut; a side pressure hole is formed on the side of the fixing nut to pass through the optical cable perforation, and the pressure plate is installed on the side pressure hole with the aid of fasteners; the inner end of the connecting nut is installed in the module fixing hole of the main module of the optical cable junction box, and sealing rings are arranged between the connecting nut and the module fixing hole, and between the double-ended external threaded connector and the connecting nut and the fixing nut; The usage method includes the following steps: S1: First, the optical cable is stripped in layers according to the specified dimensions to create a stepped interface. The stepped dimensions are related to the cone-angle pressure ring, double-ended external threaded connector, and connecting nut in the optical cable sealing and fixing module, and must be processed according to the corresponding model. S2: Assemble the optical cable sealing and fixing module: On the optical cable treated by S1, the bending protection device, fixing nut, sealing ring, and outer compression sleeve are sequentially inserted. Water-blocking gasket and compression gasket are inserted alternately. Double-ended external threaded connector is inserted. Then, the conical angle pressure ring is inserted to compress and expand the optical cable steel wire armor. Then, the inner compression gasket and water-blocking gasket are inserted alternately. Then, the inner compression sleeve, sealing ring, and connecting nut are inserted sequentially. Finally, sealant is filled. By tightening the fixing nuts and connecting nuts on both sides of the double-ended external threaded connector, the internal water-blocking gasket is compressed and deformed to achieve the sealing effect. At the same time, the compression of the internal parts will also cause the optical cable steel wire armor to deform into the reserved conical hole, which will make close contact with the conical angle pressure ring and the double-ended external threaded connector to form a tensile structure. S3: Screw the optical cable sealing and fixing module assembled in S2 into the module fixing hole on the side of the optical cable junction box. Measure the appropriate size and peel off the excess optical cable stainless steel tube layer. Fix the stainless steel tube layer on the optical fiber fixing seat with the seat cover. Cut off the excess stainless steel tube. Use the copper crimping terminal to crimp the grounding wire. Splice the optical fiber. After the optical fiber is spliced, it is coiled in the fiber splicing tray. S4: After completing the fiber coiling, close the fiber optic junction box cover and the fiber optic junction box body. Use a torque wrench to tighten the external screws of the junction box in stages according to the "tightening diagonally" principle to complete the installation.

[0010] The optical cable junction box body and the optical cable junction box cover respectively form a box body sealing ring groove and a box cover sealing ring groove that are staggered with each other. The box body sealing ring groove and the box cover sealing ring groove are respectively provided with inner and outer O-rings. Correspondingly, the box body sealing ring groove and the box cover sealing ring groove also form a box cover sealing pressure ring and a box body sealing pressure ring that are staggered with each other. S4: After the fiber coiling is completed, when the optical cable junction box cover and the optical cable junction box body are closed, the box cover sealing pressure ring presses against the O-ring of the box body sealing ring groove, and the box body sealing pressure ring presses against the O-ring of the box cover sealing ring groove. The inner and outer O-rings form two seals between the optical cable junction box cover and the optical cable junction box body.

[0011] The conical angle pressure ring forms a stepped protrusion at the end of the conical hole with a larger diameter. The stepped protrusion is supported on the end of the conical hole with a larger diameter, ensuring that the compression space between the conical hole and the conical angle pressure ring compresses and expands the optical cable steel wire armor.

[0012] The aforementioned fiber optic junction box body and cover can be made of high-strength, seawater-corrosion-resistant materials (such as titanium alloys), improving resistance to water pressure and seawater corrosion. The outer sealing element, which comes into direct contact with high-pressure seawater, requires strong corrosion resistance and high strength; the inner sealing element, which does not directly contact high-pressure seawater, has high requirements for penetration sealing. Therefore, the inner and outer sealing elements are designed with different materials. Outer sealing elements, such as compression gaskets, external O-rings, and ED sealing rings, use seawater-corrosion-resistant metal materials such as Monel (e.g., copper-nickel alloys). Inner sealing elements, such as internal O-rings and water-blocking gaskets, use fluororubber. The outer metal sealing ring can withstand ultra-high pressure of 100 MPa, has extremely high corrosion resistance, and is suitable for temperatures from -50 to 500℃, possessing characteristics that are irreplaceable by traditional sealing materials. The inner fluororubber sealing ring can block seawater penetration from the outer layer, ensuring a dry environment for the internal optical fiber. The combined use of metal and rubber sealing rings fully utilizes the respective performance advantages of both materials, achieving stability and durability of the junction box at high water depths.

[0013] This invention relates to a modular splice box, consisting of a main fiber optic splice box module and a fiber optic cable sealing and fixing module. Different types of fiber optic cables can be connected by using fiber optic cable sealing and fixing modules of different specifications, which can meet the diverse fiber optic cable connection needs in the market and can accommodate different fiber optic cable diameters (15mm-30mm) and structures (12 cores, 24 cores, 32 cores, etc.). Compared with fiber optic splice boxes on the market, it has the advantages of wide adaptability, simple operation, and reliable operation.

[0014] This invention uses a compression structure with tapered holes and tapered angle pressure rings to fix optical cables. After the fixing nut is tightened, the armored steel wires of the optical cable pass through the tapered holes and are compressed by the tapered angle pressure rings to form a tapered tensile structure with the optical cable sealing and fixing module, which makes it strong in tensile strength, reaching more than 90% of the tensile strength of the main body, and greatly improving the tensile performance of the device.

[0015] Meanwhile, the present invention forms multiple independent sealed spaces by squeezing the water-blocking gasket with a pressing sleeve to prevent water intrusion, resulting in good sealing performance. The bending protection device limits the bending radius of the optical cable to more than 5m, thus avoiding excessive bending of the optical cable.

[0016] The beneficial effects of this invention are as follows: First, the multi-layered, staggered sealing structure enhances the water-blocking and corrosion-resistant properties of the optical cable splice box, increasing its reliability and durability. Second, the optical cable sealing and fixing module performs a stepped, layered treatment of the optical cable, followed by meticulous sealing of each layer, achieving multiple efficient and reliable water-blocking measures at the connection point between the optical cable and the splice box. Furthermore, this invention emphasizes operational safety and reliability. By optimizing the sealing structure and connection method, and relying on the friction between the optical cable armor layer and the splice box, as well as the conical tensile structure, the tensile strength of the splice box is improved. In addition, bending protection devices are added at both ends to ensure the optical cable is not damaged by excessive bending. Third, the modular design of the splice box allows for the connection of optical cables of various diameters and structures, enabling the interfacing of irregularly shaped optical cables, which is of great significance for communication system interconnection. Fourth, this invention emphasizes the pre-treatment process and installation steps for the optical cable; only by following the usage method of this invention can its excellent performance be fully realized.

[0017] Compared to the traditional single-layer sealing ring of optical cable junction boxes, this invention features a double-layer staggered sealing design, effectively resisting seawater corrosion and external seawater intrusion, resulting in superior sealing performance. The central support of the box effectively resists deep-water pressure, meeting environmental performance requirements for waterproofing and corrosion resistance, as well as mechanical properties such as impact and tensile strength, ensuring operation at depths of up to 8000 meters. The junction box adopts a modular design, utilizing different specifications of optical cable sealing and fixing modules to achieve the splicing of different types of optical cables, meeting the usage requirements for optical cable junction boxes used in emergency repairs of fiber optic composite submarine cables. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments are briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is an overall schematic diagram of the invention (with the lid open); Figure 2 This is an overall schematic diagram of the present invention (with the lid closed); Figure 3 This is a top view of the internal structure of the optical cable junction box; Figure 4 This is an overall sectional view of the present invention; Figure 5 This is a sealed cross-sectional view of the main module of the optical cable junction box; Figure 6 This is a cross-sectional view of the sealing and fixing module for optical cables; Figure 7 This is a detailed enlarged view of the conical tensile structure and the sealing structure on both sides; Figure 8 This is a schematic diagram of optical cable pretreatment; Figure 9 This is a route map that the present invention can prevent from preventing seawater intrusion.

[0020] Label Explanation Fiber optic splice box main module 10: 11. Optical cable junction box body, 111. Sealing ring groove of the box body, 112. Sealing pressure ring of the box cover, 12. Sealing ring groove of the box cover, 121. Sealing pressure ring of the box body, 122. Fiber fusion splice tray, 13. Module fixing hole, 14. Inner O-ring seal, 151. Outer O-ring seal, 152. Fiber optic fixing base, 16. Base cover, 161. Grounding wire, 17. Copper crimp terminal, 18. Optical cable sealing and fixing module 20: 21. Pressure plate, 22. Fixing nut, 231 and 232. Pressure sleeve, 24. Double-ended external threaded connector, 241. Tapered hole, 25. Tapered angle pressure ring, 251. Stepped protrusion, 26. Connecting nut, 261. Sealant, 271 and 273. Water-blocking washer, 272 and 274. Compression washer, 281, 282, 283 and 284. Bending protection device, 29. Fiber optic cable 30. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that the terms front, back, inside, outside, top, bottom, left, right, first, second, third, etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the technical features indicated, unless otherwise explicitly defined.

[0023] like Figures 1 to 9 As shown, this invention discloses an optical cable splice box for emergency repair of optical fiber composite submarine cables, comprising a main body module 10 and an optical cable sealing and fixing module 20. Among them, The main module 10 of the optical cable junction box includes an optical cable junction box body 11 and an optical cable junction box cover 12, which are fitted together and fixed with standard parts such as screws and washers of various specifications. The optical cable junction box body 11 has a fiber fusion splice tray 13. A module fixing hole 14 is opened on the wall of the optical cable junction box body 11. An inner O-ring 151 and an outer O-ring 152 are provided at the joint between the optical cable junction box cover 11 and the optical cable junction box body 12. An optical fiber fixing seat 16 is also provided inside the optical cable junction box body 11. The optical fiber fixing seat 16 is located between the fiber fusion splice tray 13 and the module fixing hole 14. A seat cover 161 is installed on the optical fiber fixing seat 16.

[0024] The optical cable sealing and fixing module 20 includes a cover plate 21, a fixing nut 22, clamping sleeves 231 and 232, a double-ended external threaded connector 24, a tapered angle pressure ring 25, a connecting nut 26, and a bending protection device 29. The fixing nut 22, clamping sleeves 231 and 232, the double-ended external threaded connector 24, the tapered angle pressure ring 25, the connecting nut 26, and the bending protection device 29 form a central connection for the optical cable to pass through. One end of the double-ended external threaded connector 24 is connected to the inner end of the fixing nut 22 via an external thread, and the other end of the double-ended external threaded connector 24 is connected to the connecting nut 26 via an external thread. The external connection, the double-ended external threaded connector 24, forms a conical hole 241 in the middle, and the conical angle pressure ring 25 is installed in the conical hole 241. The conical hole 241 and the conical angle pressure ring 25 leave a compression space. The optical cable steel wire armor is squeezed and stretched in the compression space of the conical hole 241 and the conical angle pressure ring 25 by the conical angle pressure ring 25. Two clamping sleeves 231 and 232 are installed in the double-ended external threaded connector 24 and are located at both ends of the conical angle pressure ring 25 (conical angle hole 241). Water-blocking washers 271 and 273 and compression washers are installed between the clamping sleeves 231 and 232 and the two ends of the conical angle pressure ring 25 (conical angle hole 241). 272, 274 (Furthermore, the conical angle pressure ring 25 also forms a stepped protrusion 251 corresponding to the large diameter end of the conical hole 241. The stepped protrusion 251 is supported on the large diameter end of the conical hole 241, so that the conical hole 241 and the conical angle pressure ring 25 can better form a compression space for squeezing and expanding the optical cable steel wire armor). The outer end of the fixing nut 22 is also equipped with a bending limit protection device 29. A side pressure hole for penetrating the optical cable through hole is formed on the side of the fixing nut 22. The pressure plate 21 is installed on the side pressure hole with the help of fasteners such as screws. The inner end of the connecting nut 26 is installed on the module fixing of the main body module 10 of the optical cable junction box. In hole 14, O-rings 281 and three types of ED sealing rings 282, 283, and 284 are provided between the connecting nut 26 and the module fixing hole 14, and between the double-ended external threaded connector 24 and the connecting nut 26 and the fixing nut 22. (Furthermore, O-rings 281 and ED sealing rings 282 are provided between the connecting nut 26 and the module fixing hole 14, ED sealing rings 283 are provided between the compression sleeve 232 in the double-ended external threaded connector 24 and the connecting nut 26, and ED sealing rings 284 are provided between the compression sleeve 231 in the double-ended external threaded connector 24 and the fixing nut 22). Sealant 261 is also provided inside the optical cable perforation of the connecting nut 26 to seal the inner sheath of the optical cable and the connecting nut 26.

[0025] To improve sealing, the optical cable junction box body 11 and the optical cable junction box cover 12 of the present invention respectively form mutually offset box body sealing ring grooves 111 and cover sealing ring grooves 121. Corresponding to the box body sealing ring grooves 111 and 121, the optical cable junction box body 11 and the optical cable junction box cover 12 also form mutually offset cover sealing pressure rings 112 and 122. The box body sealing ring grooves 111 and 121 are respectively provided with external O-rings. When the fiber optic junction box cover 12 and the fiber optic junction box body 11 are closed, the inner O-ring 152 and the outer O-ring 152 form two seals between the cover 11 and the body 12. Simultaneously, the cover sealing ring 122 presses against the outer O-ring 152 in the body sealing ring groove 111, and the body sealing ring 112 presses against the inner O-ring 151 in the cover sealing ring groove 121. Thus, the fiber optic junction box body 11 and the cover 12 employ a combination of sealing rings and labyrinth seals, ensuring a tight fit that effectively prevents moisture penetration and improves waterproofing.

[0026] To improve sealing, two to three sets of water-blocking washers 273 and compression washers 274 are installed between the compression sleeve 232 and the conical pressure ring 25, and two to three sets of water-blocking washers 271 and compression washers 272 are installed between the compression sleeve 231 and the double-ended external threaded connector 24, forming multiple independent sealing spaces. The multi-layer sealing ring design can effectively reduce deep water pressure and prevent seawater intrusion. The figure shows that three sets of water-blocking washers 271 and compression washers 272 are staggered, and three sets of water-blocking washers 273 and compression washers 274 are staggered.

[0027] Figure 9 The diagram illustrates the seawater intrusion paths that this invention can prevent: ① intrusion into the inner sheath of the optical cable; ② intrusion into the steel wire armor layer of the optical cable; ③ intrusion at the bend limiting protection device 29; ④ intrusion between the fixing nut 22 and the double-ended external threaded connector 24; ⑤ intrusion between the connecting nut 26 and the double-ended external threaded connector 24; ⑥ intrusion between the connecting nut 26 and the optical cable junction box 11. This invention, through the optical cable sealing and fixing module 20, performs a stepped, layered treatment of the optical cable and then meticulously seals each layer, achieving multiple efficient and reliable water-blocking measures at the connection point between the optical cable and the junction box.

[0028] To improve the fixing and protection effect, one end of the bending protection device 29 of the present invention is inserted into the optical cable fixing hole of the fixing nut 22, and the other end extends out of the optical cable fixing hole, and the outer surface of the other end is a cone shape that gradually narrows along the extension direction.

[0029] The optical cable junction box main module 10 shown in the accompanying drawings of this embodiment has two module fixing holes 14, one inlet and one outlet, and each module fixing hole 14 houses an optical cable sealing and fixing module 20. Of course, the optical cable junction box main module 10 may also have four module fixing holes 14, two inlets and two outlets, with each module fixing hole 14 housing an optical cable sealing and fixing module 20.

[0030] Description of the tensile structure of the present invention: as follows Figure 6 and Figure 7 After the fixing nut 22 is tightened, the optical cable armor steel wire passes through the tapered hole 241 and is squeezed by the tapered angle pressure ring 25 to form a tapered tensile structure with the optical cable sealing and fixing module 20. The tapered hole 241 is made of sandblasting process so that its friction coefficient μ≈0.2. According to the self-locking condition μ>tanα and the overall structure consideration, the inner half cone angle α of the tapered hole 241 is selected as 5°. While ensuring that the self-locking structure is formed after the thread is tightened, the weight is reduced as much as possible. The design of the tapered tensile structure can provide extremely strong tensile performance by converting the axial force into a uniform radial contraction force. After the self-locking is triggered, the tensile performance of the device is close to the tensile performance of the original steel wire armor, realizing flexible locking of the armor layer and significantly improving the long-term mechanical reliability of the optical cable box.

[0031] Description of the waterproof structure of this invention: as follows Figure 4 and Figure 5 The seal between the fiber optic junction box body 11 and the fiber optic junction box cover 12 adopts a combination of sealing ring seal and labyrinth seal—the box body and cover are interlocked, and the inner O-ring 151 and outer O-ring 152 are filled in the sealing ring groove 111 of the box body and the sealing ring groove 121 of the cover, which can effectively prevent moisture penetration and improve waterproof performance. Meanwhile, as... Figure 6 and Figure 7 Two to three sets of water-blocking washers 271, 273 and compression washers 272, 274 are installed between the compression sleeve 232 and the conical angle pressure ring 25, and between the compression sleeve 231 and the double-ended connecting nut 24, forming multiple independent sealing spaces. As shown in the figure, the three sets of water-blocking washers 271, 273 and compression washers 272, 274 are staggered, which more effectively prevents water penetration and further improves the waterproof performance.

[0032] Description of the grounding function of this invention: as follows Figure 3After the optical cable sealing and fixing module 20 is installed, the stainless steel tube layer of the optical cable is fixed to the optical fiber fixing base 16 using the base cover 161. The grounding wire 17 is then crimped using the copper crimp terminal 18. When the optical cable splice box is subjected to a lightning strike that generates a momentary high voltage, the grounding wire 17 provides a low-impedance path for the powerful lightning current, allowing it to be safely discharged to the ground. This prevents the lightning current from breaking down the insulation structure inside the splice box or damaging the optical fiber, thus protecting equipment and communication safety. In addition, the grounding wire 17 effectively slows down or prevents electrochemical corrosion caused by potential differences, extending the life of the submarine cable. After the optical fibers are spliced, they are coiled and collected in the fiber splicing tray 13.

[0033] A method for using an optical fiber composite submarine cable emergency repair joint cassette, based on the aforementioned optical fiber composite submarine cable emergency repair joint cassette, specifically includes the following steps: S1: When using this invention, taking a 24-core B1.3 type optical cable as an example, such as... Figure 8 As shown, the optical cable 30 to be connected is first pre-processed and stripped into a stepped shape according to the specified dimensions to fit the optical cable sealing and fixing module 20. The length of the fiber splice coil needs to be reserved in advance during the pre-processing. After the optical cable sealing and fixing module 20 is installed, the excess stainless steel tube layer is cut off to reduce damage to the optical cable during the installation process.

[0034] S2: As Figure 6 and Figure 7 On the optical cable treated by S1, the following components are sequentially installed: a bend limiting protection device 29, a fixing nut 22, an ED sealing ring 284, and an outer compression sleeve 231. Water-blocking washers 271 and compression washers 272 are then installed alternately. A double-ended external threaded connector 24 is then installed. A tapered pressure ring 25 is then installed to compress and expand the optical cable steel wire armor. The inner compression washers 274 and water-blocking washers 273 are then installed alternately. The compression sleeve 232, ED sealing ring 283, connecting nut 26, ED sealing ring 282, and O-ring 281 are then installed sequentially. Finally, sealant 261 is filled in. By tightening the fixing nuts 22 and connecting nuts 26 on both sides of the double-ended external threaded connector 24, the internal water-blocking washer is squeezed and deformed to achieve a sealing effect. The end-end bending protection device 29 can reduce the friction of the optical cable sheath and limit the minimum bending radius of the optical cable to protect the optical cable. The middle cone-shaped pressure ring 25 squeezes the inner armor steel wire of the optical cable and forms a cone-shaped tensile structure with the double-ended external threaded connector 24, so that its tensile strength reaches more than 90% of the body and improves the overall tensile performance.

[0035] S3: As Figure 1 , Figure 3 and Figure 4As shown, after the optical cable sealing and fixing module 20 is installed, it is screwed into the module fixing hole 14 on the side of the optical cable junction box 11. Excess stainless steel tube layer of the optical cable is stripped to an appropriate size, and the stainless steel tube layer is fixed to the optical fiber fixing seat 16 using the seat cover 161. The grounding wire 17 is then crimped using copper crimping terminals. The grounding wire 17 has the functions of releasing static electricity, preventing leakage, balancing potential, and shielding electromagnetic interference. The optical fibers are then fused together and collected in the fusion splice tray 13.

[0036] S4: As Figure 2 As shown, after coiling the fiber, use a torque wrench to tighten the external screws of the fiber optic splice box. During the tightening process, pay attention to following the "diagonal tightening" principle, tightening in stages (e.g., tighten the two diagonal screws first, then tighten the middle ones) to avoid uneven force that could cause the box to deform and leak. This concludes the entire installation process and working principle of the fiber optic splice box.

[0037] This invention provides a cable splice storage and protection device for the maintenance of fiber optic composite submarine cables in the power and telecommunications industries. The invention features an ingenious structure. The main module 10 of the cable splice box utilizes a combination of sealing rings and labyrinth seals for sealing. The cable sealing and fixing modules 20 on both sides employ a layer-by-layer sealing method to prevent moisture infiltration. Compared to the single-layer sealing rings of traditional cable splice boxes, this method offers superior sealing performance and reliable operation. The entire invention is made of 316L stainless steel, meeting the material requirements for cable splice boxes in YD / T 814.3, ensuring waterproof and corrosion-resistant environmental performance after cable splicing, as well as impact and tensile strength. It is suitable for the fabrication of emergency repair splices for fiber optic composite submarine cables. Furthermore, this invention incorporates a conical extrusion structure designed for lightweight submarine cables to improve the tensile strength of the device.

[0038] The above description is merely an example of the implementation of the present invention and is not intended to limit the scope of protection of the present invention. It should be noted that any equivalent changes made by those skilled in the art after reading this specification, based on the design concept of this case, fall within the scope of protection of this case.

Claims

1. A method of using an optical fiber composite submarine cable emergency repair joint cassette, characterized in that: The optical cable junction box used has an optical cable junction box main module and an optical cable sealing and fixing module; The main module of the optical cable junction box includes an optical cable junction box body and an optical cable junction box cover. The optical cable junction box body has a fiber fusion splice tray, and module fixing holes are opened on the wall of the optical cable junction box body. An optical fiber fixing seat is also installed inside the optical cable junction box body. The optical fiber fixing seat is located between the fiber fusion splice tray and the module fixing holes. A seat cover is installed on the optical fiber fixing seat. The grounding wire is crimped to the optical fiber fixing seat with the help of the seat cover and the crimped copper terminal. A double-layer sealing ring with alternating inner and outer layers is set at the junction of the optical cable junction box cover and the optical cable junction box body. The optical cable sealing and fixing module includes a cover plate, a fixing nut, a clamping sleeve, a double-ended external threaded connector, a tapered angle pressure ring, a connecting nut, and a bending limit protection device. The fixing nut, clamping sleeve, double-ended external threaded connector, tapered angle pressure ring, connecting nut, and bending limit protection device form a central optical cable perforation hole. One end of the double-ended external threaded connector is connected to the inner end of the fixing nut via an external thread, and the other end is connected to the outer end of the connecting nut via an external thread. A tapered hole is formed in the middle of the double-ended external threaded connector, and the tapered angle pressure ring is installed in the tapered hole. The conical angle compression ring has a compression space; two compression sleeves are installed in the double-ended external threaded connector, with the installation positions at both ends of the conical angle compression ring; water-blocking washers and compression washers are installed between the compression sleeves and the conical angle compression ring, and a bending limit protection device is installed on the outer end of the fixing nut; a side pressure hole is formed on the side of the fixing nut to pass through the optical cable perforation, and the pressure plate is installed on the side pressure hole with the aid of fasteners; the inner end of the connecting nut is installed in the module fixing hole of the main module of the optical cable junction box, and sealing rings are arranged between the connecting nut and the module fixing hole, and between the double-ended external threaded connector and the connecting nut and the fixing nut; The usage method includes the following steps: S1: First, the optical cable is stripped in layers according to the specified dimensions to create a stepped interface. The stepped dimensions are related to the cone-angle pressure ring, double-ended external threaded connector, and connecting nut in the optical cable sealing and fixing module, and must be processed according to the corresponding model. S2: Assemble the optical cable sealing and fixing module: On the optical cable treated by S1, the bending protection device, fixing nut, sealing ring, and outer compression sleeve are sequentially inserted. Water-blocking gasket and compression gasket are inserted alternately. Double-ended external threaded connector is inserted. Then, the conical angle pressure ring is inserted to compress and expand the optical cable steel wire armor. Then, the inner compression gasket and water-blocking gasket are inserted alternately. Then, the inner compression sleeve, sealing ring, and connecting nut are inserted sequentially. Finally, sealant is filled. By tightening the fixing nuts and connecting nuts on both sides of the double-ended external threaded connector, the internal water-blocking gasket is compressed and deformed to achieve the sealing effect. At the same time, the compression of the internal parts will also cause the optical cable steel wire armor to deform into the reserved conical hole, which will make close contact with the conical angle pressure ring and the double-ended external threaded connector to form a tensile structure. S3: Screw the optical cable sealing and fixing module assembled in S2 into the module fixing hole on the side of the optical cable junction box. Measure the appropriate size and peel off the excess optical cable stainless steel tube layer. Fix the stainless steel tube layer on the optical fiber fixing seat with the seat cover. Cut off the excess stainless steel tube. Use the copper crimping terminal to crimp the grounding wire. Splice the optical fiber. After the optical fiber is spliced, it is coiled in the fiber splicing tray. S4: After completing the fiber coiling, close the fiber optic junction box cover and the fiber optic junction box body. Use a torque wrench to tighten the external screws of the junction box step by step according to the "tightening diagonally" principle to complete the installation.

2. The method of using the optical fiber composite submarine cable emergency repair joint cassette according to claim 1, characterized in that: The optical cable junction box body and the optical cable junction box cover respectively form a box body sealing ring groove and a box cover sealing ring groove that are staggered with each other. The box body sealing ring groove and the box cover sealing ring groove are respectively provided with inner and outer O-rings. Correspondingly, the box body sealing ring groove and the box cover sealing ring groove also form a box cover sealing pressure ring and a box body sealing pressure ring that are staggered with each other. S4: After the fiber coiling is completed, when the optical cable junction box cover and the optical cable junction box body are closed, the box cover sealing pressure ring presses against the O-ring of the box body sealing ring groove, and the box body sealing pressure ring presses against the O-ring of the box cover sealing ring groove. The inner and outer O-rings form two seals between the optical cable junction box cover and the optical cable junction box body.

3. The method of using the optical fiber composite submarine cable emergency repair joint cassette according to claim 1, characterized in that: The conical angle pressure ring forms a stepped protrusion at the end of the conical hole with a larger diameter. The stepped protrusion is supported on the end of the conical hole with a larger diameter, ensuring that the compression space between the conical hole and the conical angle pressure ring compresses and expands the optical cable steel wire armor.

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