End part sealing structure for hollow-core optical fiber cable and sealing prefabricated cable comprising end part sealing structure

Abstract

The utility model discloses an end part sealing structure for a hollow-core optical fiber cable and a sealing prefabricated cable comprising the end part sealing structure, which belong to the technical field of hollow-core optical fiber matching, and comprise a sealing locking cap and a sealing thermal shrinkage cap which are arranged in a combined manner. 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 part sealing structure for the hollow-core optical fiber cable is simple in structure and convenient to assemble, can reliably realize the end part sealing of the hollow-core optical fiber cable, prevents impurities from entering a transmission channel of the hollow-core optical fiber to influence the subsequent transmission quality of the hollow-core optical fiber, and improves the service life of the hollow-core optical fiber cable. The hollow-core optical fiber cable can be laid in a humid environment or a complex gas environment, 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] The utility model belongs to hollow core optical fiber supporting technology field, more particularly to be used for the end sealing structure of hollow core optical fiber cable and the sealed preform cable containing it. BACKGROUND

[0002] Hollow core optical fiber has the advantages of low delay, high power, high bandwidth, ultra-low nonlinear effect, etc., and is one of the most promising new optical fibers. Since the hollow core optical fiber has a hollow transmission channel, it is easy for water, carbon dioxide or other gas molecules to enter the optical cable / optical fiber transmission channel during transportation and construction. These substances can produce absorption peaks at specific transmission wavelengths, affecting the transmission performance of the optical fiber. Therefore, the sealing of the hollow core optical fiber is extremely important.

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

[0004] In the prior art, a plug is usually used to seal the end of the hollow core optical fiber. However, since the optical fiber has a small diameter (usually not more than 0.5 mm), and the control area of the hollow core optical fiber is also small, it is difficult to directly seal the end of the hollow core optical fiber by the plug. Although the applicant has proposed a sealing end structure in the prior art document CN119045138A, in which a sealing ring is used to seal the end of the hollow core optical fiber cable, which can meet the needs of practical application to a certain extent. However, since the sealing ring is easily deformed by external force during construction, resulting in problems such as loose sealing and water seepage at the end of the optical cable, there is still a certain limitation in use. UTILITY MODEL CONTENTS

[0005] In view of one or more of the above defects or improvement needs of the prior art, the utility model provides an end sealing structure for a hollow core optical fiber cable and a sealed preform cable containing the same, which can realize reliable sealing of the end of the hollow core optical fiber cable, ensure the end sealing reliability of the hollow core optical fiber cable during transportation and construction, and improve the performance of the hollow core optical fiber cable after laying.

[0006] To achieve the above-mentioned purpose, in one aspect of the utility model, an end sealing structure for a hollow core optical fiber cable is provided for sealing the end of the hollow core optical fiber cable, comprising:

[0007] A sealing locking cap, having a first sealing hole with one end open and the other end closed; a locking portion is formed at the end of the open side of the first sealing hole, and the locking portion can be sealingly sleeved on the outer periphery of the end of the hollow core optical fiber cable to form a first level sealing of the end of the hollow core optical fiber cable;

[0008] A sealing heat shrink cap, made of heat shrink material, having a second sealing hole with one end open and the other end closed; the sealing heat shrink cap can be sleeved on the outer periphery of the sealing locking cap after the sealing locking cap is fixed on the end of the hollow core optical fiber cable; and

[0009] The length of the sealing heat shrink cap is greater than the length of the sealing locking cap, so that the sealing heat shrink cap can be heat shrinked and fixed on the outer periphery of the hollow core optical fiber cable after the open end of the sealing heat shrink cap passes over the locking portion, to form a second level sealing of the end of the hollow core optical fiber cable.

[0010] As a further improvement of the utility model, a sealing member is further included;

[0011] The sealing member is formed by coating and curing glue on the end of the hollow core optical fiber cable, and is used for pre-sealing the end of the hollow core optical fiber cable sleeved with the sealing locking cap.

[0012] As a further improvement of the utility model, the sealing locking cap is made of metal material; and / or, the sealing member is made of silicone rubber or polyurethane sealant.

[0013] As a further improvement of the utility model, the length of the locking portion is less than the length of the first sealing hole, so that after the sealing locking cap is connected with the hollow core optical fiber cable through the locking portion, a containing cavity is formed between the closed end of the first sealing hole and the end of the hollow core optical fiber cable provided with the sealing member.

[0014] As a further improvement of the utility model, a water vapor adsorbent is arranged in the containing cavity;

[0015] And / or

[0016] The length of the containing cavity is 20mm-40mm;

[0017] And / or

[0018] The length of the locking portion is 10mm-20mm.

[0019] As a further improvement of the utility model, the locking portion includes an internal thread arranged on the inner wall surface of the first sealing hole;

[0020] The inner diameter of the internal thread is 0.1mm-0.3mm smaller than the outer diameter of the hollow core fiber cable, and the outer diameter of the internal thread is 0.1mm-0.3mm larger than the outer diameter of the hollow core fiber cable.

[0021] As a further improvement of the utility model, the thickness of the sealing heat shrink cap after heat shrinkage is 0.2mm-0.5mm.

[0022] And / or

[0023] The minimum wall thickness of the locking portion area is 0.1mm-0.3mm.

[0024] And / or

[0025] After the sealing heat shrink cap is tightly fastened, the length of the sealing heat shrink cap heat shrunk on the outer periphery of the hollow core fiber cable is not less than 10mm, and the interval between the closed end of the sealing heat shrink cap and the closed end of the second sealing hole is 10mm-30mm.

[0026] As a further improvement of the utility model, a limiting convex ring is further included; the limiting convex ring can be sleeved and fixed on the outer periphery of the hollow core fiber cable on one side of the sealing heat shrink cap.

[0027] As a further improvement of the utility model, the interval between the limiting convex ring arranged on the outer periphery of the hollow core fiber cable and the end portion of the sealing heat shrink cap is 10mm-30mm.

[0028] Another aspect of the utility model also provides a sealing prefabricated cable, which comprises a hollow core fiber cable, and at least one end of the hollow core fiber cable is provided with the end sealing structure for the hollow core fiber cable.

[0029] As a further improvement of the utility model, the sealing prefabricated 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.

[0030] The above improvement technical features can be combined with each other as long as they do not conflict with each other.

[0031] Overall, compared with the prior art, the above technical scheme conceived by the utility model has the beneficial effects including:

[0032] The utility model discloses a end sealing structure for hollow core fiber optic cable, which comprises a sealing locking cap and a sealing heat shrink cap arranged in combination, and the two sealing components are arranged correspondingly at the end of the hollow core fiber optic cable.

[0033] The end sealing structure for hollow core fiber optic cable has simple structure, convenient assembly, and can reliably seal the end of the hollow core fiber optic cable, improve the sealing effect of the hollow core fiber after the hollow core fiber optic cable is formed, avoid the influence of impurities entering the transmission channel of the hollow core fiber on the subsequent transmission quality of the hollow core fiber, and enable the hollow core fiber optic cable to be laid in a humid environment or a complex gas environment, effectively improve the convenience of laying and using the hollow core fiber optic cable, and have excellent use value. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the utility model, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings.

[0035] Figure 1 is a structure schematic view of the end sealing structure for hollow core fiber optic cable in the embodiment 1 of the utility model;

[0036] Figure 2 is a structure schematic view of the end sealing structure for hollow core fiber optic cable in the embodiment 2 of the utility model;

[0037] Figure 3 is a structure schematic view of the end sealing structure for hollow core fiber optic cable in the embodiment 3 of the utility model;

[0038] In all the drawings, the same reference signs represent the same technical features, specifically:

[0039] 1, sealing element; 2, sealing locking cap; 3, sealing heat shrink cap; 4, limiting convex ring; 5, hollow core fiber optic cable;

[0040] 201, first sealing hole; 2011, locking part; 2012, accommodating cavity; 202, water vapor adsorbent; 301, second sealing hole; 501, cable outer sheath. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as there is no conflict.

[0042] In the description of the utility model, it should be understood that, unless otherwise explicitly specified and limited, the orientation or positional relationship indicated by 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" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0043] In addition, unless otherwise explicitly limited, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the utility model, the meaning of "multiple" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0044] In the utility model, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise explicitly limited. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0045] In the utility model, unless another definite provision and limitation, first feature is on second feature "on" or "under" can be first and second feature direct contact, or first and second feature indirectly contact through intermediate medium. Moreover, first feature is on second feature "on", "above" and "upper surface" can be first feature is directly above or obliquely above second feature, or just indicate that first feature horizontal height is higher than second feature. First feature is on second feature "under", "below" and "under surface" can be first feature is directly below or obliquely below second feature, or just indicate that first feature horizontal height is less than second feature.

[0046] Below, reference Figures 1-2 The end sealing structure suitable for the hollow core fiber optical cable 5, the hollow core fiber optical cable 5 with end sealing and the end sealing method of the hollow core fiber optical cable 5 based on the end sealing structure according to the preferred embodiment of the utility model are described.

[0047] For the end sealing structure in the preferred embodiment, it aims to realize reliable sealing of the end of the hollow core fiber optical cable 5, avoid impurities (water, gas) outside the optical cable from entering the internal transmission channel of the hollow core fiber during the transportation and laying of the hollow core fiber optical cable 5, and ensure the use reliability and transmission performance of the hollow core fiber optical cable 5 after laying.

[0048] In the embodiment 1 as Figure 1 The end sealing structure of the hollow core fiber optical cable 5 preferably includes a sealing locking cap 2 and a sealing heat shrink cap 3.

[0049] The sealing locking cap 2 has a first sealing hole 201 with one end open and the other end closed; the end of the first sealing hole 201 on the open side is formed with a locking part 2011, and the locking part 2011 can be sealingly sleeved on the outer periphery of the end of the hollow core fiber optical cable 5 to form the first level sealing of the end of the hollow core fiber optical cable 5.

[0050] At the same time, the sealing heat shrink cap 3 is made of heat shrink material, which has a second sealing hole 301 with one end open and the other end closed; the sealing 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 on the end of the hollow core fiber optical cable 5, and the end of the sealing heat shrink cap 3 can pass over the locking part 2011 and be heat shrink fastened on the outer periphery of the hollow core fiber optical cable 5 to form the second level sealing of the end of the hollow core fiber optical cable 5.

[0051] It can be understood that the sealing locking cap 2 is heat shrink covered by the sealing heat shrink cap 3, that is, the middle part of the sealing heat shrink cap 3 is heat shrink fastened on the outer periphery of the sealing locking cap 2.

[0052] For the technical solution in Embodiment 1, the first sealing hole 201 and the second sealing hole 301 are both blind holes with one end open and the other end closed, the sealing sleeve of the end of the hollow core fiber optical cable 5 is sleeved from the open end of the blind hole, the path of impurities from the end break of the hollow core fiber optical cable 5 into the internal transmission channel of the hollow core fiber is cut off, and the cleanliness of the internal transmission channel of the hollow core fiber optical cable 5 is ensured.

[0053] In order to further improve the sealing performance of the end sealing structure, it is further preferred that a pre-sealing is arranged at the end of the hollow core fiber optical cable 5, and at this time, as shown in Embodiment 2, it is further preferred that the sealing member 1 is arranged at the end of the hollow core fiber optical cable 5. Figure 2

[0054] For the sealing member 1 in the preferred embodiment, it is preferably formed by coating and curing the sealant at the end of the hollow core fiber optical cable 5 after the end face is cut flat.

[0055] More specifically, the sealant is preferably a silicone sealant or a polyurethane sealant, and the sealant is arranged at the end of the optical cable by means of coating or by immersing the end of the optical cable in the sealant, and after the sealant is arranged, the sealing member 1 is formed by means of heat curing or light curing.

[0056] In actual arrangement, it is preferred that the sealing locking cap 2 is sleeved on the end of the optical cable after the sealing member 1 is completely cured. Before the curing operation, it is preferred that the glue liquid exceeding the outer periphery of the sealing member 1 is removed, so that the outer periphery of the sealing member 1 does not excessively protrude from the surface of the outer sheath 501 of the optical cable after the sealing member 1 is cured.

[0057] Of course, it can be understood that after the laying of the hollow core fiber optical cable 5 is completed, the end provided with the sealing member 1 is preferably cut off, so as to ensure the performance reliability of the optical cable actually used and avoid the pollution of the end of the optical cable.

[0058] Further, the length of the locking portion 2011 in the preferred embodiment is less than the length of the first sealing hole 201, so that after the sealing locking cap 2 is connected to the hollow core fiber optical cable 5 by the locking portion 2011, the closed end of the first sealing hole 201 and the end of the hollow core fiber optical cable 5 provided with the sealing member 1 form a receiving cavity 2012.

[0059] The reason for arranging the receiving cavity 2012 is to avoid that part of the members (for example, reinforcing members) in the hollow core fiber optical cable 5 directly abut against the closed end of the first sealing hole 201 after protruding from the end face of the optical cable, to reserve sufficient redundant space for part of the members to protrude from the end face of the optical cable, so as to avoid that the sealing locking cap 2 is pushed out from the end of the optical cable due to the pushing of the corresponding members, and to ensure the reliability of the sealing locking cap 2 arranged at the end of the optical cable.

[0060] ​In more detail, considering thermal expansion and contraction and the problem that the sealant itself releases water molecules with temperature and humidity changes, in the preferred embodiment, it is further preferred that a water vapor adsorbent 202 is fixed and filled in the accommodation cavity 2012 to effectively absorb water vapor that accidentally enters the accommodation cavity 2012, ensuring the dryness of the end of the optical cable.

[0061] As an example, the water vapor adsorbent 202 in the accommodation cavity 2012 is preferably fixed on the inner wall surface of the accommodation cavity 2012 by adhesive means to prevent the water vapor adsorbent 202 from falling into the hollow core optical fiber cable 5 due to falling off, ensuring the reliability of the end sealing of the hollow core optical fiber cable 5.

[0062] In actual operation, the fixing process of the water vapor adsorbent 202 in the accommodation cavity 2012 is preferably as follows: first, glue is applied to the inner wall surface of the accommodation cavity 2012, then the water vapor adsorbent 202 is filled in the accommodation cavity 2012, and after the glue in the accommodation cavity 2012 is cured, the water vapor adsorbent 202 not adsorbed in the accommodation cavity 2012 is removed through vibration test and air injection test, so that a layer of water vapor adsorbent 202 is adsorbed on the inner wall surface of the accommodation cavity 2012 and is not easy to fall off.

[0063] Of course, for the scheme in the embodiment 2 provided with the sealing member 1, due to the end plugging of the sealing member 1, at this time, the water vapor adsorbent 202 embedded in the accommodation cavity 2012 can be preferably directly embedded or adhered and fixed, which will not be described here.

[0064] It can be understood that in actual setting, the longer the setting length of the locking part 2011 and the accommodation cavity 2012, the better the locking and sealing effect and reliability. However, the sealing and locking cap 2 that is too long will increase the material cost on the one hand, and will also affect the stress stability of the end sealing structure on the other hand.

[0065] Therefore, in the preferred embodiment, the length of the locking part 2011 is preferably 10mm-20mm. And / or, the length of the accommodation cavity 2012 is 20mm-40mm.

[0066] Further 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 and locking cap 2 is fixed on the optical cable outer sheath 501 at the end of the optical cable by thread engagement.

[0067] In order to better realize the thread engagement of the locking portion 2011, the inner diameter of the internal thread in the preferred embodiment is preferably 0.1mm-0.3mm smaller than the outer diameter of the hollow core fiber optical cable 5, so that the end portion of the optical cable can be locked at the end portion of the optical cable with a certain degree of interference fit. At the same time, the outer diameter of the internal thread is preferably 0.1mm-0.3mm larger than the outer diameter of the hollow core fiber optical cable 5, i.e. the thickness of the tooth portion of the internal thread is 0.1mm-0.3mm. By setting the outer diameter of the internal thread to be larger than the outer diameter of the hollow core fiber optical cable 5, it can be ensured that the tooth portion of the internal thread can be reliably embedded in the outer sheath 501 of the optical cable, ensuring the reliability of the threaded sleeve.

[0068] In addition, for the locking portion 2011, the thickness of the minimum wall thickness region (corresponding to the region of the outer diameter of the internal thread) is 0.1mm-0.3mm. By setting it in this way, it can be known that after the outer peripheral locking sleeve of the sealing and locking cap 2 is set on the end portion of the optical cable, the increased outer diameter of the end portion of the optical cable is only 0.3mm-0.9mm.

[0069] Further, in the embodiment 3 as shown in Figure 3 As a feasible example, the first sealing hole 201 is preferably set in the form of a stepped hole, at this time, the inner diameter of the locking portion 2011 is larger than the inner diameter of the accommodating cavity 2012, and an annular step surface is formed at the junction of the locking portion 2011 and the accommodating cavity 2012, which can be used as a limiting surface when the end portion of the hollow core fiber optical cable 5 is embedded, to ensure that the locking portion 2011 is properly sleeved on the end portion of the optical cable.

[0070] In more detail, the thickness of the sealing and heat-shrinking cap 3 after heat-shrinking in the preferred embodiment is preferably 0.2mm-0.5mm, and on this basis, the size of the outer diameter of the end portion of the optical cable increased after the sealing and heat-shrinking cap 3 is completed heat-shrinking is 0.4mm-1.0mm. That is to say, after the overall end portion sealing structure is completed (after the sealing and heat-shrinking cap 3 is sleeved on the outer periphery of the sealing and locking cap 2), the newly added size is 0.7mm-1.9mm, and the overall size increases by a small amount, which does not excessively affect the transportation and laying of the hollow core fiber optical cable 5.

[0071] In addition, in order to ensure the sealing performance of the sealing and heat-shrinking cap 3 after being set, the length of the sealing and heat-shrinking cap 3 (corresponding to the length of the second sealing hole 301) is preferably designed, so that the length of the sealing and heat-shrinking cap 3 heat-shrunk on the outer periphery of the hollow core fiber optical cable 5 is not less than 10mm, and is further preferably 20mm. At the same time, the closed end of the sealing and locking cap 2 and the closed end of the second sealing hole 301 are preferably spaced apart, and the spacing therebetween is preferably 10mm-30mm.

[0072] Further, in order to avoid the falling off of the end sealing structure during the transportation and laying of the hollow core fiber cable 5, a limiting convex ring 4 is preferably arranged. The limiting convex ring 4 can be sleeved and fixed on the outer periphery of the hollow core fiber cable 5 on one side of the sealing heat shrink cap 3, which can be used as the axial limiting when the cable is pulled by the net, so as to avoid the slipping between the net and the cable, and also avoid the pulling off of the end sealing structure due to the slipping of the net, thereby fully ensuring the reliability of the end sealing structure.

[0073] In actual arrangement, the limiting convex ring 4 is arranged on the outer sheath 501 of the cable on the side of the opening end of the sealing heat shrink cap 3, and the distance between the limiting convex ring 4 and the end of the hollow core fiber cable 5 is greater than the length of the sealing locking cap 2, and the distance between the end of the sealing heat shrink cap 3 heat shrunk on the end of the hollow core fiber cable 5 and the limiting convex ring 4 is 10-30 mm.

[0074] In addition, for the limiting convex ring 4, the fixing mode on the outer periphery of the cable outer sheath 501 is preferably heat shrinkage or gluing. When the fixing mode of the limiting convex ring 4 is heat shrinkage, the limiting convex ring 4 is arranged in the form of a sleeve by heat shrinkable material, which can directly pass through the end of the cable and be sleeved on the outer periphery of the cable, and then be fixed by heat shrinkage after being slid to the corresponding position. When the fixing mode of the limiting convex ring 4 is gluing, the limiting convex ring 4 can be formed by winding the adhesive tape material on the outer periphery of the cable outer sheath 501 after gluing and curing.

[0075] More preferably, the sealing locking cap 2 is preferably made of metal material, such as stainless steel or aluminum alloy material. Of course, it can be understood that the sealing locking cap 2 can also be made of non-metal material according to the needs, such as ceramic material, which is not described here.

[0076] As another aspect of the present application, based on the design of the aforementioned end sealing structure, a kind of end sealing method suitable for hollow core fiber cable 5 is further provided, which preferably includes the following processes:

[0077] (1) after cutting the end of the hollow core fiber cable 5 flat, the end is sealed by sealing glue, and the sealing piece 1 is arranged on the end of the hollow core fiber cable 5.

[0078] (2) after the sealing glue is completely cured and formed, the sealing locking cap 2 is sleeved on the end of the hollow core fiber cable 5 provided with the sealing piece 1, so that the locking part 2011 of the sealing locking cap 2 is sealingly sleeved on the outer periphery of the end of the hollow core fiber cable 5. At the same time, the length of the locking part 2011 sealingly sleeved is preferably 10-20 mm.

[0079] In actual arrangement, after the sealing sleeving of the sealing locking cap 2 is completed, it is further preferred to perform spot gluing treatment on the end of the sealing locking cap 2 in a ring shape, to further improve the sealing effect after the sealing locking cap 2 is arranged.

[0080] (3) The sealing heat shrink cap 3 is sleeved on the outer periphery of the sealing locking cap 2, and the open end of the sealing heat shrink cap 3 is made to pass over the locking portion 2011 of the sealing locking cap 2.

[0081] In actual setting, the length of the open end of the sealing heat shrink cap 3 passing over the locking portion 2011 is preferably not less than 10 mm, for example, 20 mm, so as to ensure that the sealing heat shrink cap 3 can be in sufficient contact with and locked to the outer periphery of the hollow core fiber optical cable 5.

[0082] (4) The sealing heat shrink cap 3 is heated to heat shrink and fasten the end portion of the sealing heat shrink cap 3 to the outer periphery of the hollow core fiber optical cable 5, and heat shrink and fasten the middle portion of the sealing heat shrink cap 3 to the outer periphery of the sealing locking cap 2, thereby completing the end sealing of the hollow core fiber optical cable 5.

[0083] In actual setting, if the heat shrink setting of the limiting protruding ring 4 exists, it is preferably set in advance before process (1) is performed; at this time, the limiting protruding ring 4 is first sleeved on the outer periphery of the hollow core fiber optical cable 5, and after a sufficient length is reserved, the limiting protruding ring 4 is heat shrunk and fixed. In order to ensure the reliability of the setting of the limiting protruding ring 4, the inner wall surface of the limiting protruding ring 4 can be further preferably coated with glue, so that the heat shrunk and fixed limiting protruding ring 4 can be fully locked to the optical cable outer sheath 501.

[0084] Of course, if the limiting protruding ring 4 is formed in a winding and gluing manner, its forming process can be performed before the end sealing structure is set, or can be performed after the end sealing structure is set, which is not described herein.

[0085] As another aspect of the present application, a sealed preformed cable with the aforementioned end sealing structure is also provided, which is preferably prepared by pre-setting the end sealing structure on at least one end of the hollow core fiber optical cable 5, and the production of the end sealing structure is preferably preformed in the factory, so that the aforementioned sealed preformed cable can fully avoid impurities 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 use performance of the hollow core fiber optical cable 5.

[0086] As an example, in a specific embodiment, the aforementioned sealed preformed cable is a hybrid optical cable formed by mixing the hollow core fiber optical cable 5 with solid core fiber optical cables. The solid core fiber optical cable includes at least one solid core fiber unit, and the solid core fiber unit includes a loose tube and a plurality of solid core optical fibers wrapped by the loose tube. In more detail, the specification of the aforementioned solid core optical fiber is G.652D, G.654E or G.655.

[0087] It can be understood that for the end sealing structure in the preferred embodiment, it can correspond to the end of the hollow core fiber optical cable 5 connected at both ends of the hybrid optical cable, so as to ensure that the hollow core fiber core is fully protected.

[0088] The end sealing structure for the hollow core fiber optical cable is simple in structure, convenient to assemble, can reliably realize end sealing of the hollow core fiber optical cable, improves sealing effect of the hollow core fiber after the hollow core fiber optical cable is formed, avoids affecting subsequent transmission quality of the hollow core fiber due to impurities entering a transmission channel of the hollow core fiber, enables the hollow core fiber optical cable to be laid in a humid environment or a complex gas environment, effectively improves convenience of laying and use of the hollow core fiber optical cable, and has excellent use value.

[0089] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An end seal structure for a hollow core fiber optical cable for sealing an end portion of a hollow core fiber optical cable, characterized by, The application relates to an end sealing structure for an air-core optical fiber cable. The sealing locking cap has a first sealing hole with one open end and the other closed end; The first sealing hole is provided with a locking part at the end of the open end, the locking part can be tightly sleeved on the outer periphery of the end of the air-core optical fiber cable to form a first-stage sealing of the end of the air-core optical fiber cable; The sealing thermal shrinkage cap is made of thermal shrinkage material and has a second sealing hole with one open end and the other closed end; the sealing thermal shrinkage cap can be sleeved on the outer periphery of the sealing locking cap after the sealing locking cap is fixed on the end of the air-core optical fiber cable; and The length of the sealing thermal shrinkage cap is greater than the length of the sealing locking cap, so that the sealing thermal shrinkage cap can be tightly fixed on the outer periphery of the air-core optical fiber cable after the open end of the sealing thermal shrinkage cap passes over the locking part, to form a second-stage sealing of the end of the air-core optical fiber cable. The application further comprises a sealing member; 2. An end seal structure for a hollow core fiber optic cable according to claim 1, wherein, The sealing member is formed by coating and curing glue on the end of the air-core optical fiber cable, and is used for pre-sealing the end of the air-core optical fiber cable sleeved with the sealing locking cap. The sealing locking cap is made of metal material; and / or the sealing member is made of silicone rubber or polyurethane sealant.

3. An end seal structure for a hollow core fiber optic cable according to claim 2, wherein, The length of the locking part is less than the length of the first sealing hole, so that, after the sealing locking cap is connected to the air-core optical fiber cable with the locking part, a containing cavity is formed between the closed end of the first sealing hole and the end of the air-core optical fiber cable provided with the sealing member.

4. The end-seal structure for a hollow-core fiber optic cable of claim 1, wherein, A water vapor adsorbent is fixedly arranged in the containing cavity.

5. An end seal structure for a hollow core fiber optic cable according to claim 4, wherein, The length of the containing cavity is 20mm-40mm.

6. An end seal structure for a hollow core fiber optic cable according to claim 4, wherein, The length of the locking part is 10mm-20mm.

7. An end seal structure for a hollow core fiber optic cable according to claim 4, characterized in that, The locking part comprises an internal thread arranged on the inner wall surface of the first sealing hole; 8. The end seal structure for a hollow core fiber optic cable of any one of claims 1-7, wherein, The internal thread has an inner diameter which is 0.1mm-0.3mm smaller than the outer diameter of the air-core optical fiber cable, and an outer diameter which is 0.1mm-0.3mm greater than the outer diameter of the air-core optical fiber cable. The thickness of the sealing thermal shrinkage cap after thermal shrinkage is 0.2mm-0.5mm.

9. An end seal structure for a hollow core fiber optic cable according to claim 8, wherein, The minimum wall thickness of the locking part region is 0.1mm-0.3mm.

10. The end seal structure for a hollow core fiber optic cable of claim 8, wherein, After the sealing thermal shrinkage cap is tightly fixed, the length of the sealing thermal shrinkage cap which is thermally shrunk on the outer periphery of the air-core optical fiber cable is not less than 10mm, and the interval between the closed end of the sealing locking cap and the closed end of the second sealing hole is 10mm-30mm.

11. An end seal structure for a hollow core fiber optic cable according to claim 8, wherein, The application further comprises a limiting convex ring; the limiting convex ring can be sleeved and fixed on the outer periphery of the air-core optical fiber cable on one side of the sealing thermal shrinkage cap.

12. The end-seal structure for a hollow-core fiber optic cable of any of claims 1-7, 9-11, wherein, The distance between the limiting convex ring and the end of the air-core optical fiber cable is greater than the length of the sealing locking cap, and the interval between the sealing thermal shrinkage cap which is thermally shrunk on the end of the air-core optical fiber cable and the limiting convex ring is 10mm-30mm.

13. An end seal structure for a hollow core fiber optic cable according to claim 12, wherein, At least one end of the air-core optical fiber cable is provided with the end sealing structure for the air-core optical fiber cable according to any one of claims 1-13.

14. A sealed preform cable comprising a hollow core fiber optic cable, characterized by, ​ 15. The sealed pre-cable of claim 14, wherein, The sealing pre-cable is a hybrid optical cable formed after a hollow optical fiber cable and a solid optical fiber cable are mixed into a cable; wherein the solid optical fiber cable comprises at least one solid optical fiber unit, the solid optical fiber unit comprises a loose tube and a plurality of solid optical fibers wrapped by the loose tube, and the solid optical fibers have a specification of G.652D, G.654E or G.655.

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