End part sealing structure and sealing method of hollow-core optical fiber cable and sealing prefabricated cable

Abstract

The invention discloses an end sealing structure and sealing method of a hollow-core optical fiber cable and a sealing prefabricated cable, and belongs to the technical field of hollow-core optical fiber matching, the end sealing structure comprises a sealing element, a sealing locking cap and a sealing thermal shrinkage cap which are arranged in a combined mode, and the three sealing elements are sequentially arranged at the end of the hollow-core optical fiber cable; multi-stage sealing of the end part of the hollow-core optical fiber cable can be realized, and the end part sealing effect of the hollow-core optical fiber cable is effectively ensured while the arrangement reliability of the end part sealing structure at the end part of the optical cable is ensured. The end sealing structure of the hollow-core optical fiber cable is simple in structure and convenient to assemble, end sealing of the hollow-core optical fiber cable can be reliably achieved, the situation that impurities enter a transmission channel of the hollow-core optical fiber to affect the follow-up transmission quality of the hollow-core optical fiber cable is avoided, the hollow-core optical fiber cable can be laid in a humid environment or a complex gas environment, and the service life of the hollow-core optical fiber cable is prolonged. The convenience of laying and using the hollow-core optical fiber cable is effectively improved, and the hollow-core optical fiber cable has excellent use value.

Description

Technical Field

[0001] This invention belongs to the field of hollow optical fiber supporting technology, specifically relating to an end sealing structure, end sealing method and sealed prefabricated cable for hollow optical fiber cable. Background Technology

[0002] Hollow-core optical fiber boasts advantages such as low latency, high power, high bandwidth, and ultra-low nonlinear effects, making it one of the most promising new types of optical fibers. However, due to its hollow transmission channel, water, carbon dioxide, or other gas molecules can easily enter the optical cable / fiber transmission channel during transportation and construction. These substances can generate absorption peaks at specific transmission wavelengths, affecting the fiber's transmission performance. Therefore, the sealing of hollow-core optical fibers is extremely important.

[0003] During the transportation and construction of optical cables, the environment in which hollow optical fiber cables are located is often complex and uncontrollable. In particular, there is often a large amount of water in the underground pipelines during construction. How to ensure reliable sealing of the optical cable during construction has become an important issue.

[0004] In existing technologies, plugs are typically used to seal the ends of hollow optical fibers. However, due to the small diameter of the optical fiber (usually no more than 0.5 mm) and the small central control area of ​​the hollow fiber, it is difficult to directly seal the ends of the hollow fiber using plugs. Although the applicant proposed a sealing end structure in prior patent document CN119045138A, which uses a sealing ring to seal the ends of the hollow optical fiber cable, it can meet the needs of practical applications to a certain extent. However, the sealing ring is easily deformed by external forces during construction, leading to problems such as loose sealing and water leakage at the cable ends, thus still having certain limitations in use. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides an end sealing structure, sealing method and sealing prefabricated cable for hollow optical fiber cables, which can achieve reliable sealing of the ends of hollow optical fiber cables, ensure the reliability of end sealing of hollow optical fiber cables during transportation and construction, and improve the performance of hollow optical fiber cables after laying.

[0006] To achieve the above objectives, one aspect of the present invention provides an end-sealing structure for a hollow-core optical fiber cable, used to seal the end of the hollow-core optical fiber cable, comprising: A sealing element; the sealing element is used to be disposed at the end of the hollow fiber optic cable to achieve a first-level seal at the end of the hollow fiber optic cable; A sealing locking cap; the sealing locking cap has a first sealing hole that is open at one end and closed at the other end; a locking part is formed at the end of the first sealing hole on the open side, the locking part can be sealed and fitted onto the outer periphery of the end of the hollow optical fiber cable to form a second-level seal at the end of the hollow optical fiber cable; and the length of the locking part is less than the length of the first sealing hole, and a receiving cavity is formed in the closed end of the first sealing hole on the side away from the locking part. A heat-shrinkable sealing cap; the heat-shrinkable sealing cap is made of heat-shrinkable material and has a second sealing hole that is open at one end and closed at the other end; the heat-shrinkable sealing cap can be sleeved on the outer periphery of the sealing locking cap after the sealing locking cap is fixed to the end of the hollow fiber optic cable, and the end of the heat-shrinkable sealing cap can pass over the locking part and be heat-shrinkably fastened to the outer periphery of the hollow fiber optic cable, so as to form a third-level seal at the end of the hollow fiber optic cable.

[0007] As a further improvement of the present invention, a water vapor adsorbent is provided in the accommodating cavity.

[0008] As a further improvement of the present invention, the length of the accommodating cavity is 20mm~40mm; and / or The length of the locking part is 10mm~20mm.

[0009] As a further improvement of the present invention, the locking part includes an internal thread provided on the inner wall surface of the first sealing hole; The inner diameter of the internal thread is 0.1mm to 0.3mm smaller than the outer diameter of the hollow optical fiber cable, and the outer diameter of the internal thread is 0.1mm to 0.3mm larger than the outer diameter of the hollow optical fiber cable.

[0010] As a further improvement of the present invention, the thickness of the heat-shrinkable sealing cap after heat shrinking is 0.2mm~0.5mm; and / or The minimum wall thickness of the locking region is 0.1mm to 0.3mm; and / or After the heat-shrink cap is heat-shrinked and tightened, its length shrunken to the outer periphery of the hollow optical fiber cable is not less than 10mm, and the closed end of the sealing locking cap is spaced 10mm~30mm from the closed end of the second sealing hole.

[0011] As a further improvement of the present invention, a limiting protrusion ring is also included; the limiting protrusion ring can be sleeved and fixed to the outer periphery of the hollow optical fiber cable on one side of the sealing heat shrink cap.

[0012] As a further improvement of the present invention, the distance between the limiting protrusion ring disposed on the outer periphery of the hollow optical fiber cable and the end of the sealing heat shrink cap is 10mm~30mm.

[0013] As a further improvement of the present invention, the sealing locking cap is made of a metal material; and / or The seal is made of silicone rubber or polyurethane sealant.

[0014] In another aspect, the present invention provides a method for sealing the end of a hollow optical fiber cable, for setting the end sealing structure of the hollow optical fiber cable at the end of the cable, comprising the following steps: (1) The sealing element is provided at the end of the hollow optical fiber cable; (2) A sealing locking cap is fitted onto the end of the hollow optical fiber cable where a sealing element is provided, so that the locking part of the sealing locking cap is sealed and connected to the outer periphery of the end of the hollow optical fiber cable. (3) A heat-shrinkable sealing cap is fitted around the outer periphery of the sealing locking cap, and the open end of the heat-shrinkable sealing cap extends beyond the locking part of the sealing locking cap; (4) Heat the heat-shrink cap to heat-shrink and fasten the end of the heat-shrink cap to the outer periphery of the hollow fiber optic cable, and heat-shrink and fasten the middle part of the heat-shrink cap to the outer periphery of the sealing locking cap, thereby completing the end sealing of the hollow fiber optic cable.

[0015] In another aspect, the present invention provides a sealed prefabricated cable comprising a hollow optical fiber cable, wherein at least one end of the hollow optical fiber cable is provided with an end sealing structure of the hollow optical fiber cable.

[0016] As a further improvement of the present invention, the sealed prefabricated cable is a hybrid optical cable formed by mixing hollow optical fiber cable and solid optical fiber cable; wherein, the solid optical fiber cable includes at least one solid optical fiber unit, the solid optical fiber unit includes a loose tube and multiple solid optical fibers wrapped by the loose tube, and the specification of the solid optical fiber is G.652D, G.654E or G.655.

[0017] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0018] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include: The end sealing structure of the hollow fiber optic cable in this invention includes a combination of sealing components, a sealing locking cap, and a sealing heat shrink cap. By utilizing the corresponding arrangement of the three sealing components at the end of the hollow fiber optic cable, the reliability of the end sealing structure at the end of the cable can be ensured while achieving multi-level sealing at the end of the hollow fiber optic cable. Furthermore, the sealing components are nested layer by layer, working together to effectively ensure the end sealing effect of the hollow fiber optic cable, thus creating conditions for the subsequent reliable use of the hollow fiber optic cable.

[0019] The end-sealing structure of the hollow fiber optic cable in this invention is simple in structure and easy to assemble. It can reliably achieve end sealing of the hollow fiber optic cable, improve the sealing effect of the hollow fiber after the cable is formed, and prevent impurities from entering the transmission channel of the hollow fiber, thus affecting the subsequent transmission quality of the hollow fiber. This allows the hollow fiber optic cable to be laid in humid or complex gas environments, effectively improving the convenience of laying and using the hollow fiber optic cable, and has excellent application value. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the end sealing structure of a hollow optical fiber cable in one embodiment of the present invention; Figure 2 This is a schematic diagram of the end sealing structure of a hollow optical fiber cable in another embodiment of the present invention; In all the accompanying drawings, the same reference numerals denote the same technical features, specifically: 1. Sealing element; 2. Sealing locking cap; 3. Sealing heat shrink cap; 4. Limiting protrusion ring; 5. Hollow-core optical fiber cable; 201, First sealing hole; 2011, Locking part; 2012, Receiving cavity; 202, Water vapor adsorbent; 301, Second sealing hole; 501, Optical cable outer sheath. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] In the description of this invention, it should be understood that, unless otherwise expressly specified and limited, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0024] Furthermore, unless otherwise expressly defined, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] Below, for reference Figures 1-2 The present invention describes an end-sealing structure applicable to a hollow fiber optic cable 5 according to a preferred embodiment of the present invention, a hollow fiber optic cable 5 with end sealing, and an end-sealing method for the hollow fiber optic cable 5 based on the end-sealing structure.

[0028] For the end sealing structure in the preferred embodiment, it aims to achieve a reliable seal at the end of the hollow fiber optic cable 5, preventing impurities (water, gas) outside the cable from entering the internal transmission channel of the hollow fiber optic cable 5 during transportation and laying, and ensuring the reliability and transmission performance of the hollow fiber optic cable 5 after laying.

[0029] Specifically, in the preferred embodiment, the end sealing structure of the hollow fiber optic cable 5 includes a sealing element 1, a sealing locking cap 2, and a sealing heat shrink cap 3.

[0030] The sealing element 1 is used to be installed at the end of the hollow fiber optic cable 5 to achieve the first-level sealing at the end of the hollow fiber optic cable 5.

[0031] Meanwhile, the sealing locking cap 2 has a first sealing hole 201 that is open at one end and closed at the other end; a locking part 2011 is formed at the end of the first sealing hole 201 on the open side, and the locking part 2011 can be sealed and fitted onto the outer periphery of the end of the hollow fiber optic cable 5 to form a second-level seal at the end of the hollow fiber optic cable 5. In addition, the length of the locking part 2011 is less than the length of the first sealing hole 201, and a receiving cavity 2012 is formed in the closed end of the first sealing hole 201 on the side away from the locking part 2011.

[0032] In addition, the heat-shrink cap 3 is made of heat-shrinkable material and has a second sealing hole 301 that is open at one end and closed at the other end. The heat-shrink cap 3 can be sleeved on the outer periphery of the sealing locking cap 2 after the sealing locking cap 2 is fixed to the end of the hollow fiber optic cable 5, and the end of the heat-shrink cap 3 can pass over the locking part 2011 and be heat-shrink and fastened to the outer periphery of the hollow fiber optic cable 5 to form a third-level seal at the end of the hollow fiber optic cable 5.

[0033] It is easy to see that in the preferred embodiment, both the first sealing hole 201 and the second sealing hole 301 are blind holes with one end open and the other end closed. The end of the hollow fiber optic cable 5 is sealed by the open end of the blind hole, and then the end opening of the optical cable is directly closed by the sealing element 1, cutting off the path for impurities to enter the internal transmission channel of the hollow fiber optic cable 5 from the end break, thereby ensuring the cleanliness of the internal transmission channel of the hollow fiber optic cable 5. Moreover, based on the setting of the accommodating cavity 2012 in the first sealing hole 201, after the sealing locking cap 2 is locked at the end of the optical cable, there is a certain distance between the closed end of the first sealing hole 201 and the end of the optical cable. In this way, even if some components (specifically the reinforcing members) in the optical cable accidentally protrude, there is a certain amount of redundant space to prevent the sealing locking cap 2 from being accidentally pushed out.

[0034] Furthermore, for the seal 1 in the preferred embodiment, it is preferably formed by curing a sealant on the end face of the optical cable after the end face has been cut flat. The sealant is preferably silicone rubber or polyurethane sealant, which is applied to the end of the optical cable by coating or by immersing the end of the optical cable in the sealant. After the sealant is applied, the seal 1 is formed by heat curing or light curing.

[0035] In actual installation, it is preferable to place the sealing cap 2 onto the end of the optical cable only after the sealant 1 has fully cured. Before the curing process, it is preferable to remove any adhesive that extends beyond the outer periphery of the sealant 1 to prevent the sealant 1 from protruding excessively from the surface of the outer sheath 501 of the optical cable after curing.

[0036] Of course, it is understandable that after the hollow fiber optic cable 5 is laid, it is preferable to cut off the end with the sealing element 1 to ensure the performance reliability of the actual optical cable and avoid end contamination of the optical cable.

[0037] More specifically, considering thermal expansion and contraction and the issue that the sealant itself may release water molecules as temperature and humidity change, in the preferred embodiment, it is further preferred to fill the accommodating cavity 2012 with a water vapor adsorbent 202, which can effectively absorb water vapor that accidentally enters the accommodating cavity 2012 and ensure the dryness of the optical cable end.

[0038] It is understandable that, in actual installation, the longer the locking part 2011 and the receiving cavity 2012 are, the better the locking and sealing effect and reliability. However, an excessively long sealing locking cap 2 will increase material costs and affect the stress stability of the end sealing structure.

[0039] Therefore, in the preferred embodiment, the length of the locking part 2011 is preferably 10mm to 20mm. And / or, the length of the accommodating cavity 2012 is 20mm to 40mm.

[0040] More preferably, the locking part 2011 of the first sealing hole 201 includes an internal thread provided on the inner wall surface of the first sealing hole 201, and the sealing locking cap 2 is sleeved and fixed on the outer sheath 501 of the optical cable at the end of the optical cable by means of thread engagement.

[0041] To better achieve thread engagement of the locking part 2011, in the preferred embodiment, the inner diameter of the internal thread is preferably 0.1mm to 0.3mm smaller than the outer diameter of the hollow fiber optic cable 5. This allows the end of the optical cable to be locked in place with a certain degree of interference fit. Simultaneously, the outer diameter of the internal thread is preferably 0.1mm to 0.3mm larger than the outer diameter of the hollow fiber optic cable 5, meaning the tooth thickness of the internal thread is 0.1mm to 0.3mm. By setting the outer diameter of the internal thread to be larger than the outer diameter of the hollow fiber optic cable 5, it can be ensured that the teeth of the internal thread can reliably embed into the outer sheath 501 of the optical cable, guaranteeing the reliability of the threaded connection.

[0042] Furthermore, for the locking part 2011, the thickness of its minimum wall thickness area (the area corresponding to the outer diameter of the internal thread) is 0.1mm to 0.3mm. With this setting, it can be seen that after the sealing locking cap 2 is locked onto the outer periphery of the optical cable end, the increased outer diameter of the optical cable end is only 0.3mm to 0.9mm.

[0043] As a feasible example, in actual setup, it is preferable to set the first sealing hole 201 as a stepped hole. In this case, the inner diameter of the locking part 2011 is larger than the inner diameter of the accommodating cavity 2012, and an annular stepped surface is formed at the junction of the locking part 2011 and the accommodating cavity 2012. This annular stepped surface can serve as a limiting surface when the end of the hollow fiber optic cable 5 is embedded, ensuring that the locking part 2011 is properly sleeved at the end of the optical cable.

[0044] More specifically, in the preferred embodiment, the thickness of the heat-shrinkable cap 3 after heat shrinking is preferably 0.2mm to 0.5mm. Based on this, the increase in the outer diameter of the optical cable end after heat shrinking the heat-shrinkable cap 3 is 0.4mm to 1.0mm. That is to say, after the end sealing structure is fully installed (after the heat-shrinkable cap 3 is fitted around the sealing locking cap 2), the additional size is 0.7mm to 1.9mm. The overall increase in size is not significant and will not have a major impact on the transportation and laying of the hollow optical fiber cable 5.

[0045] Furthermore, to ensure the sealing performance of the heat-shrink cap 3 after installation, the length of the heat-shrink cap 3 (corresponding to the length of the second sealing hole 301) is preferably designed so that after heat shrinking and tightening, the length of the heat-shrink cap 3 extending beyond the outer periphery of the hollow optical fiber cable 5 is not less than 10 mm, and more preferably 20 mm. Simultaneously, the closed end of the sealing locking cap 2 and the closed end of the second sealing hole 301 are preferably spaced apart, with the interval between them preferably being 10 mm to 30 mm.

[0046] Furthermore, to prevent the end sealing structure of the hollow fiber optic cable 5 from falling off during transportation and laying, a limiting protrusion ring 4 is preferably provided. The limiting protrusion ring 4 can be sleeved and fixed to the outer periphery of the hollow fiber optic cable 5 on one side of the sealing heat shrink cap 3, so as to serve as an axial limit when the cable is pulled by the mesh sleeve, preventing slippage between the mesh sleeve and the cable, and also preventing the end sealing structure from being pulled off due to the slippage of the mesh sleeve, thus fully ensuring the reliability of the end sealing structure.

[0047] In actual installation, the limiting protrusion 4 is set on the optical cable outer sheath 501 on one side of the opening end of the sealing heat shrink cap 3, and the distance between it and the end of the sealing heat shrink cap 3 is 10mm to 30mm.

[0048] Furthermore, for the limiting protrusion ring 4, its fixing method on the outer periphery of the optical cable outer sheath 501 is preferably heat shrinking or adhesive bonding. When the limiting protrusion ring 4 is fixed by heat shrinking, the limiting protrusion ring 4 is made of heat shrinkable material in the form of a sleeve, which can directly pass through the end of the optical cable and be sleeved on the outer periphery of the optical cable. After it slides to the corresponding position, it can be fixed by heat shrinking. When the limiting protrusion ring 4 is fixed by adhesive bonding, it can be formed by wrapping an adhesive strip around the outer periphery of the optical cable outer sheath 501 and then bonding and curing it.

[0049] More preferably, the sealing cap 2 is made of a metallic material, such as stainless steel or aluminum alloy. Of course, it is understood that the sealing cap 2 may also be made of a non-metallic material, such as ceramic material, as needed, which will not be elaborated here.

[0050] As another aspect of the present invention, based on the aforementioned end-sealing structure design, an end-sealing method suitable for hollow optical fiber cable 5 is further provided, which preferably includes the following process: (1) After cutting the end of the hollow fiber optic cable 5 flat, seal the end with sealant and set the sealing element 1 at the end of the hollow fiber optic cable 5.

[0051] (2) After the sealant has fully cured, a sealing locking cap 2 is fitted onto the end of the hollow fiber optic cable 5 where the sealing element 1 is located, so that the locking part 2011 of the sealing locking cap 2 is fitted onto the outer periphery of the end of the hollow fiber optic cable 5. At the same time, the length of the sealing fit of the locking part 2011 is preferably 10mm to 20mm.

[0052] In actual installation, after the sealing sleeve of the sealing locking cap 2 is completed, it is even more preferable to apply a dotted adhesive treatment to the end of the sealing locking cap 2 in the circumferential direction to further improve the sealing effect after the sealing locking cap 2 is installed.

[0053] (3) A sealing heat shrink cap 3 is fitted around the outer periphery of the sealing locking cap 2, and the open end of the sealing heat shrink cap 3 extends beyond the locking part 2011 of the sealing locking cap 2.

[0054] In actual installation, the length of the opening end of the sealing heat shrink cap 3 extending beyond the locking part 2011 is preferably not less than 10mm, for example 20mm, to ensure that the sealing heat shrink cap 3 can fully contact and lock with the outer periphery of the hollow fiber optic cable 5.

[0055] (4) Heat the heat-shrink cap 3 to heat-shrink and fasten the end of the heat-shrink cap 3 to the outer periphery of the hollow fiber optic cable 5, and heat-shrink and fasten the middle part of the heat-shrink cap 3 to the outer periphery of the sealing locking cap 2, thereby completing the end sealing of the hollow fiber optic cable 5.

[0056] In actual setup, if a heat-shrinkable limiting ring 4 is present, it is preferable to set the limiting ring 4 before process (1). In this case, the limiting ring 4 is first fitted onto the outer periphery of the hollow fiber optic cable 5, and after reserving sufficient length, the limiting ring 4 is heat-shrinkably fixed. To ensure the reliability of the limiting ring 4, it is also preferable to coat the inner wall surface of the limiting ring 4 with glue so that the heat-shrink fixed limiting ring 4 can be fully locked with the outer sheath 501 of the optical cable.

[0057] Of course, if the limiting protrusion ring 4 is formed by winding and gluing, the forming process can be carried out before or after the end sealing structure is set, which will not be elaborated here.

[0058] As another aspect of the present invention, a sealed prefabricated cable with the aforementioned end sealing structure is also provided. It is preferably manufactured by pre-setting the end sealing structure on at least one end of the hollow fiber optic cable 5, and the end sealing structure is preferably prefabricated in the factory. In this way, the aforementioned sealed prefabricated cable can fully prevent impurities from entering the transmission channel of the optical cable after leaving the factory, thereby ensuring the reliability of the optical cable during transportation, storage and laying, and improving the performance of the hollow fiber optic cable 5.

[0059] As an example, in one specific embodiment, the aforementioned sealed prefabricated cable is a hybrid optical cable formed by mixing hollow-core optical fiber cable 5 and solid-core optical fiber cable. The solid-core optical fiber cable includes at least one solid-core optical fiber unit, and the solid-core optical fiber unit includes a loose tube and multiple solid-core optical fibers wrapped by the loose tube. More specifically, the specifications of the aforementioned solid-core optical fibers are G.652D, G.654E, or G.655.

[0060] It is understood that, for the end sealing structure in the preferred embodiment, it can be connected to the ends of the hollow fiber optic cables 5 at both ends of the hybrid optical cable, so as to ensure that the hollow fiber core is fully protected.

[0061] The end-sealing structure of the hollow fiber optic cable in this invention is simple in structure and easy to assemble. It can reliably achieve end sealing of the hollow fiber optic cable, improve the sealing effect of the hollow fiber after the cable is formed, and prevent impurities from entering the transmission channel of the hollow fiber, thus affecting the subsequent transmission quality of the hollow fiber. This allows the hollow fiber optic cable to be laid in humid or complex gas environments, effectively improving the convenience of laying and using the hollow fiber optic cable, and has excellent application value.

[0062] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An end seal structure of a hollow core fiber cable for sealing an end portion of a hollow core fiber cable, characterized by, The application relates to a sealing device for an end of a hollow core fiber cable. The sealing device comprises: a sealing member, which is arranged at the end of the hollow core fiber cable to form a first-stage sealing of the end of the hollow core fiber cable; a sealing locking cap; the sealing locking cap has a first sealing hole with an open end and a closed end; the end of the open end is provided with a locking part, which is sealingly sleeved on the outer periphery of the end of the hollow core fiber cable to form a second-stage sealing of the end of the hollow core fiber cable; and the length of the locking part is smaller than the length of the first sealing hole, and a receiving cavity is formed in the closed end of the first sealing hole away from the locking part; 2. The end seal structure of a hollow-core fiber optic cable according to claim 1, characterized by, a sealing heat-shrinkable cap made of a heat-shrinkable material, which has a second sealing hole with an open end and a closed end; the sealing heat-shrinkable cap is sleeved on the outer periphery of the sealing locking cap after the sealing locking cap is fixed on the end of the hollow core fiber cable, and the end of the sealing heat-shrinkable cap is heat-shrunk and fixed on the outer periphery of the hollow core fiber cable to pass the locking part to form a third-stage sealing of the end of the hollow core fiber cable.

3. The end seal structure of a hollow-core fiber optic cable according to claim 2, characterized by, The receiving cavity is provided with a water vapor adsorbent. The length of the receiving cavity is 20mm-40mm; And / or 4. The end seal structure of a hollow-core fiber optic cable according to any one of claims 1 to 3, characterized in that, The length of the locking part is 10mm-20mm. The locking part comprises an internal thread arranged on the inner wall surface of the first sealing hole; 5. The end seal structure of a hollow-core fiber optic cable according to claim 4, characterized by, The internal diameter of the internal thread is 0.1mm-0.3mm smaller than the external diameter of the hollow core fiber cable, and the external diameter of the internal thread is 0.1mm-0.3mm larger than the external diameter of the hollow core fiber cable. The thickness of the sealing heat-shrinkable cap after heat-shrinking is 0.2mm-0.5mm; And / or The minimum wall thickness of the locking part region is 0.1mm-0.3mm; And / or 6. The end seal structure of a hollow-core fiber optic cable according to any one of claims 1 to 3, 5, wherein After heat-shrinking and fixing, the length of the sealing heat-shrinkable cap heat-shrunk on the outer periphery of the hollow core fiber cable is not smaller than 10mm, and the closed end of the sealing locking cap is spaced from the closed end of the second sealing hole by 10mm-30mm.

7. The end seal structure of a hollow-core fiber optic cable according to claim 6, characterized by, The sealing device further comprises a limiting convex ring, which is sleeved and fixed on the outer periphery of the hollow core fiber cable on one side of the sealing heat-shrinkable cap.

8. The end seal structure of a hollow-core fiber optic cable according to any one of claims 1-3, 5, 7, characterized in that, The spacing between the limiting convex ring arranged on the outer periphery of the hollow core fiber cable and the end of the sealing heat-shrinkable cap is 10mm-30mm. The sealing locking cap is made of a metal material; And / or 9. A method of sealing an end portion of a hollow core fiber optical cable for providing the end portion sealing structure of any one of claims 1 to 8 at an end portion of a hollow core fiber optical cable, characterized by, The sealing member is made of silicone rubber or polyurethane sealant. The application further discloses a sealing process of the sealing device. (1) arranging the sealing member at the end of the hollow core fiber cable; (2) sleeving the sealing locking cap on the end of the hollow core fiber cable provided with the sealing member, so that the locking part of the sealing locking cap is sealingly connected on the outer periphery of the end of the hollow core fiber cable; (3) sleeving the sealing heat-shrinkable cap on the outer periphery of the sealing locking cap, and making the open end of the sealing heat-shrinkable cap pass the locking part of the sealing locking cap; (4) heating the sealing heat-shrinkable cap, heat-shrinking and fixing the end of the sealing heat-shrinkable cap on the outer periphery of the hollow core fiber cable, and heat-shrinking and fixing the middle part of the sealing heat-shrinkable cap on the outer periphery of the sealing locking cap, thereby completing the sealing of the end of the hollow core fiber cable.

10. A sealed preform cable comprising a hollow core fiber optic cable, characterized by, At least one end of the hollow core fiber cable is provided with the end sealing structure of the hollow core fiber cable according to any one of claims 1-8.

11. The sealed pre-cable of claim 10, wherein, The sealing pre-cable is a mixed optical cable formed after the hollow core fiber cable and the solid core fiber cable are mixed into a cable; wherein the solid core fiber cable comprises at least one solid core fiber unit, the solid core fiber unit comprises a loose tube and a plurality of solid core fibers wrapped by the loose tube, and the specification of the solid core fiber is G.652D, G.654E or G.655.

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