A multi-core butterfly cable

Abstract

The present application relates to the field of optical fiber communication, and particularly relates to a multi-core butterfly optical cable. The optical cable comprises an optical fiber bundle structure and an optical cable sheath arranged outside the optical fiber bundle structure; the optical fiber bundle structure comprises at least one optical fiber bundle unit, each optical fiber bundle unit comprises a central optical fiber and N layers of stranded optical fibers arranged outside the central optical fiber, the first layer of stranded optical fibers comprises six stranded optical fibers, and the first layer of stranded optical fibers are stranded together around the central optical fiber with a stranded pitch P1; the i-th layer of stranded optical fibers comprises 6*i stranded optical fibers, and the i-th layer of stranded optical fibers are stranded together around the (i-1)-th layer of stranded optical fibers with a stranded pitch P i , wherein P i i-1 ; each layer of stranded optical fibers satisfies that the stranded optical fibers in the layer are arranged in a circular ring shape, the gaps between the optical fibers in each optical fiber bundle unit are filled with a polymer optical fiber coating, and the outer diameters of the stranded optical fibers in each layer are equal to the corresponding stranded outer diameters. The present application improves the consistency of optical fiber performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber communication, in particular to a multi-core butterfly cable. BACKGROUND

[0002] Optical cables are widely used in various industries, and most of the multi-core optical fiber cables in the current optical fiber communication industry are limited by structural design and production process. There are unstable and uncertain length differences between the optical fibers and between the optical fibers and the cable sheath, which is not conducive to the consistency of the multi-core optical fiber optical transmission, tensile, bending and temperature attenuation performance. How to improve the consistency of the performance of the optical fibers in the multi-core optical fiber is a problem to be solved. SUMMARY

[0003] The present application aims to provide a multi-core butterfly cable to improve the consistency of the performance of the optical fibers in the multi-core optical fiber.

[0004] The multi-core butterfly cable of the present application comprises: an optical fiber bundle structure and a cable sheath arranged outside the optical fiber bundle structure; the optical fiber bundle structure comprises at least one optical fiber bundle unit, each optical fiber bundle unit comprises a central optical fiber and N layers of twisted optical fibers outside the central optical fiber, N≥2, wherein the first layer of twisted optical fibers comprises 6 twisted optical fibers, and the first layer of twisted optical fibers is twisted together around the central optical fiber with a twisting pitch P1; the i-th layer of twisted optical fibers comprises 6*i twisted optical fibers, and the i-th layer of twisted optical fibers is twisted together around the (i-1)-th layer of twisted optical fibers with a twisting pitch P i ; the (i+1)-th layer of twisted optical fibers comprises 6*(i+1) twisted optical fibers, and the (i+1)-th layer of twisted optical fibers is twisted together around the i-th layer of twisted optical fibers with a twisting pitch P i ; the value of i ranges from 2 to N, N is the number of layers of twisted optical fibers outside the central optical fiber, and d is the diameter of the central optical fiber and each twisted optical fiber; the twisted optical fibers in each layer of twisted optical fibers are arranged in a circular ring shape, the gap between the central optical fiber and the twisted optical fibers and the gap between the twisted optical fibers in each optical fiber bundle unit are filled with a high-molecular optical fiber coating, and the outer diameter of each layer of twisted optical fibers is equal to the corresponding twisted outer diameter. The present application has obvious beneficial effects compared with the prior art. The multi-core butterfly cable of the present application can achieve considerable technical progress and practicality, and has wide industrial utilization value, and at least has the following beneficial effects:

[0005] The multi-core butterfly cable of the present application comprises a central optical fiber and N layers of twisted optical fibers outside the central optical fiber, the first, second, …, N layers of twisted optical fibers comprise 6, 12, …, 6*N twisted optical fibers, the diameters of the central optical fiber and each twisted optical fiber are the same, the twisting pitch P i of the i-th layer of twisted optical fibers satisfies P

[0006] ​Thus, the excess length of the first layer of stranded optical fibers is equal to the excess length of the i-th layer of stranded optical fibers, and the consistency of the performance of the optical fibers in the multi-core butterfly optical cable is improved. The gaps between the optical fibers in the optical fiber bundle are filled with polymer optical fiber coating, the polymer optical fiber coating plays a role of adhesion and fixation of the optical fibers, and the structure of the optical fiber bundle is relatively stable. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0008] Figure 1 A cross-sectional structure schematic diagram of the multi-core butterfly optical cable provided by the first embodiment of the present application is shown in the figure.

[0009] Figure 2 A cross-sectional structure schematic diagram of the optical fiber bundle unit provided by the first embodiment of the present application is shown in the figure.

[0010] Figure 3 A cross-sectional structure schematic diagram of the optical fiber bundle belt provided by the second embodiment of the present application is shown in the figure.

[0011] Figure 4 A cross-sectional structure schematic diagram of the multi-core butterfly optical cable provided by the second embodiment of the present application is shown in the figure.

[0012] Figure 5 A cross-sectional structure schematic diagram of the optical fiber bundle structure provided by the third embodiment of the present application is shown in the figure.

[0013] Figure 6 A cross-sectional structure schematic diagram of the optical fiber bundle belt provided by the fourth embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0015] The present application provides a multi-core butterfly optical cable, comprising an optical fiber bundle structure and an optical cable sheath arranged outside the optical fiber bundle structure.

[0016] According to the present invention, the fiber bundle structure includes at least one fiber bundle unit, each fiber bundle unit including a central fiber and N layers of stranded fibers located outside the central fiber, where N≥2. The stranded fibers are arranged in a ring, wherein the first layer of stranded fibers includes 6 stranded fibers stranded together around the central fiber with a stranding pitch P1; the second layer of stranded fibers includes 12 stranded fibers stranded together around the first layer of stranded fibers with a stranding pitch P2; and so on, the i-th layer of stranded fibers includes 6*i stranded fibers stranded together with a stranding pitch P... i The fibers are twisted together around the (i-1)th layer of stranded fiber, where i ranges from 2 to N, and N is the number of layers of stranded fiber outside the central fiber.

[0017] According to the present invention, the diameters of the central optical fiber and the stranded optical fiber are equal, both being d. The stranding pitch of the six stranded optical fibers in the first layer is P1, and the helix length of the first layer stranded optical fiber at a single pitch is... Yu Chang The twist pitch of the 12 stranded optical fibers in the second layer is P2. The helix length of the second-layer stranded optical fibers at a single pitch is... Yu Chang When the excess length of the first layer of stranded fiber is equal to the excess length of the second layer of stranded fiber, that is... At that time, the first layer of stranded optical fiber and the second layer of stranded optical fiber have equal lengths, and the first layer of stranded optical fiber and the second layer of stranded optical fiber have equal excess lengths relative to the central optical fiber, which can improve the consistency of optical fiber performance in the multi-core butterfly optical cable of the present invention. According to It can be deduced that: Therefore, once P1 is determined, P2 can be uniquely determined.

[0018] Similarly, the twist pitch of the 6*i stranded optical fibers in the i-th layer is P. i The helix length of the i-th layer stranded fiber at a single pitch Yu Chang When the excess length of the first layer of stranded fiber is equal to the excess length of the i-th layer of stranded fiber, that is... At that time, the lengths of the first layer of stranded optical fiber and the i-th layer of stranded optical fiber are equal, and the first layer of stranded optical fiber and the i-th layer of stranded optical fiber have equal excess length relative to the central optical fiber, which can improve the consistency of optical fiber performance in the multi-core butterfly optical cable of the present invention. According to It can be deduced that: Therefore, once P1 is determined, P can be uniquely determined. i .

[0019] According to the application, the gap between the center optical fiber and the stranded optical fiber and the gap between the stranded optical fibers in each optical fiber bundle unit are filled with a high-molecular optical fiber coating. Preferably, the high-molecular optical fiber coating is an ultraviolet light curing resin or a heat curing coating or a thermoplastic material, which can well adhere and fix the optical fibers. In the production process of the multi-core butterfly cable, the number of discharge ports of the filling mold is the same as the number of stranded optical fibers in each layer, the shape of the discharge port is designed to completely coincide with the gap between the optical fibers, the rotation speed of the filling mold is consistent with the stranded speed of the optical fiber cage, which ensures that each layer of stranded optical fibers is arranged in a circular ring shape, and the high-molecular optical fiber coating fills the stranded gap completely, so that the outer diameter of each layer of stranded optical fibers is exactly equal to the corresponding stranded outer diameter.

[0020] In the application, the optical fiber bundle unit is formed by one-way stranding of a plurality of optical fibers and filling and curing of a high-molecular optical fiber coating. The high-molecular optical fiber coating ensures easy tearing while fixing the optical fibers. The optical fibers and the filling material (i.e. the high-molecular optical fiber coating) can be separated by holding the optical fiber bundle unit of the application and twisting it in the opposite direction of the optical fiber stranding, and the plurality of optical fibers can be separated at one time. The application has a great improvement in peelability compared with conventional optical fiber bundles.

[0021] In the application, each layer of stranded optical fibers in the optical fiber bundle unit is filled with a filling material to fill the stranded boundary into a complete circle, and there is no problem of embedding the outer layer of optical fibers into the inner layer when the adjacent layers are stranded in the same stranding direction, which can damage the complete circular structure. Therefore, the stranding directions of the adjacent two layers of stranded optical fibers can be opposite or the same. When the stranding directions of the adjacent stranded optical fibers are the same, each layer of optical fibers can be separated by twisting in the opposite direction of the single stranding direction when peeling. When the stranding directions of the adjacent stranded optical fibers are opposite, the stranded optical fibers need to be peeled and separated layer by layer, and the twisting directions of the stranded optical fibers of the adjacent layers are opposite.

[0022] Preferably, the cable jacket is a butterfly cable jacket, and the material of the butterfly cable jacket is a low-modulus soft plastic.

[0023] Preferably, a reinforcing member is arranged in the cable jacket. The reinforcing member is made of a glass fiber reinforced plastic (GFRP) or a coated steel wire with high rigidity, and the cross section of the reinforcing member is circular.

[0024] Preferably, different colors of filling materials are used to distinguish the optical fiber bundle units, and the optical fibers in the optical fiber bundle units are distinguished by coloring.

[0025] As a first embodiment, the optical fiber bundle structure includes one optical fiber bundle unit, as shown in Figure 1As shown in the figure. In this embodiment, N=2, where 1 is the fiber bundle unit, 2 is the optical cable sheath, and 3 is the reinforcing member. In this embodiment, there are two reinforcing members 3, symmetrically arranged on both sides of the fiber bundle 1. A schematic diagram of the cross-sectional structure of the fiber bundle unit 1 is shown below. Figure 2 As shown, 4 is the central optical fiber, 5 is the stranded optical fiber of the first layer, 6 is the stranded optical fiber of the second layer, and 7 is the polymer optical fiber coating.

[0026] In a second embodiment, the fiber bundle structure includes two or more fiber bundle units. In this embodiment, N=2, such as... Figure 3 As shown, the number of fiber bundle units is 5. These 5 fiber bundle units are arranged in parallel to form a fiber bundle ribbon. Adjacent fiber bundle units are tightly connected by a polymer fiber coating 7. The center lines of each fiber bundle unit are kept straight, parallel to each other, and coplanar. In this invention, the flatness of the fiber bundle ribbon is less than or equal to 50 nm. The flatness of the fiber bundle ribbon refers to the sum of the absolute values ​​of the maximum positive deviation and the maximum negative deviation of the vertical position of the fiber bundle unit. In this invention, the stranded fiber lengths of each fiber bundle unit are equal. According to the arrangement of each fiber bundle unit in this embodiment, the lengths of each fiber bundle unit are equal. Therefore, the lengths of all stranded fibers in the fiber bundle structure are equal, and the lengths of all central fibers are also equal, improving the consistency of fiber performance in multi-core fibers. In this embodiment, the number of reinforcing members is 4, which are respectively set at the four corners of the optical cable sheath, such as... Figure 4 As shown, this helps to reduce the size of multi-core butterfly optical cables. In this embodiment, the optical cable sheath is a butterfly optical cable sheath, such as... Figure 4 As shown, the symmetrical tear groove 8 of the optical cable sheath is located at the center line of the optical fiber bundle and the opening points towards the optical fiber bundle structure, with a separation force requirement of 5 to 15 N.

[0027] As a third embodiment, the fiber bundle structure includes two or more fiber bundle units, such as... Figure 5 As shown. In this embodiment, N=2, and the fiber bundle structure includes a central fiber bundle unit and M layers of stranded fiber bundle units located outside the central fiber bundle unit, where M≥2. The first layer of stranded fiber bundle units includes 6 stranded fiber bundle units, which are stranded together around the central fiber bundle unit with a stranding pitch Q1. The j-th layer of stranded fiber bundle units includes 6*j stranded fiber bundle units, which are stranded together with a stranding pitch Q1. j The fiber bundles are twisted together around the (j-1)th layer stranded fiber unit, Q j satisfy j is in the range of 2 to M, M is the number of layers of the stranded fiber bundle units outside the central fiber bundle unit, D is the diameter of the central fiber bundle unit and each stranded fiber bundle unit; the stranded fiber bundle units in each layer of the stranded fiber bundle units are arranged in a circular ring shape, the gaps between the central fiber bundle unit and the stranded fiber bundle units and the gaps between the stranded fiber bundle units in the fiber bundle structure are filled with polymer optical fiber coating, and the polymer optical fiber coating just fills the stranded gaps to make the outer diameter of each layer of the stranded fiber bundle units equal to the corresponding stranded outer diameter. In the present application, the lengths of the stranded fibers of each fiber bundle unit are equal, and according to the arrangement mode of each fiber bundle unit in the embodiment, the lengths of each stranded fiber bundle unit are equal, so that the lengths of the stranded fibers of all the stranded fiber bundle units in the fiber bundle structure are equal, and the lengths of the central fibers of all the stranded fiber bundle units are also equal, thereby improving the consistency of the performance of the optical fibers in the multi-core optical fiber. In the embodiment, the number of reinforcing members is 2, and the reinforcing members are symmetrically arranged on both sides of the fiber bundle 1.

[0028] As a fourth embodiment, the fiber bundle structure includes a plurality of fiber bundle substructures, and the plurality of fiber bundle substructures are arranged in parallel to form a fiber bundle belt, as shown in Figure 6 The adjacent fiber bundle substructures are connected by polymer optical fiber coating, and each fiber bundle substructure includes a central fiber bundle unit and M layers of stranded fiber bundle units outside the central fiber bundle unit.

[0029] The shrinkage of the butterfly cable sheath is mainly caused by the elastic tensile deformation and rebound of the reinforcing member due to the laying tension, and the shrinkage rate of the sheath after cabling is zero. The laying tension of the fiber bundle unit is set to be the same as the strain of the optical fiber and the strain of the reinforcing member caused by the laying tension of the reinforcing member, and the length of the central optical fiber after cabling is completely equal to the length of the cable, and all the stranded fibers have an equal positive excess length relative to the cable. In the production process of the multi-core butterfly cable, the laying tension of the reinforcing member is F s , the modulus of the reinforcing member is E s , the cross-sectional area of the reinforcing member is S s , and the tensile deformation of the reinforcing member during laying is The laying tension of the fiber bundle unit is F f , the modulus of the fiber bundle is E f , the cross-sectional area of the fiber bundle is S f , and the tensile deformation of the fiber bundle during laying is It is required that s = ε f .

[0030] The experimental results show that the cable sheath character error in the present application is 0-0.05%, the length difference between the central optical fiber and the cable sheath is not more than 0.05%, and the length difference between the stranded fibers is also not more than 0.05%, and the length difference can be further controlled within the range of ±0.02%.

[0031] While certain specific embodiments of the application have been described in detail herein for the purposes of exemplification, numerous other variations and modifications will be apparent to persons skilled in the art. Alterations and modifications of detail can be made by those skilled in the art, having the benefit of the above description, without departing from the spirit and scope of the application. It is intended that all such alterations and modifications be included within the scope of the application whose limits are to be determined only by the appended claims.

Claims

1. A multi-fiber butterfly cable, characterized by, The application relates to a cable structure, which comprises: a fiber bundle structure and a cable sheath arranged outside the fiber bundle structure; The optical fiber bundle structure comprises at least one optical fiber bundle unit, each optical fiber bundle unit comprises a center optical fiber and N layers of twisted optical fibers outside the center optical fiber, N≥2, wherein the first layer of twisted optical fibers comprises 6 twisted optical fibers, the first layer of twisted optical fibers is twisted together around the center optical fiber at a twisting pitch P1, the length of the helical line of the first layer of twisted optical fibers in a single pitch , the excess length ; the i-th layer of twisted optical fibers comprises 6*i twisted optical fibers, the i-th layer of twisted optical fibers is twisted together around the (i-1)-th layer of twisted optical fibers at a twisting pitch P i , the length of the helical line of the i-th layer of twisted optical fibers in a single pitch , the excess length , P i satisfies , i ranges from 2 to N, N is the number of layers of the twisted optical fibers outside the center optical fiber, and d is the diameter of the center optical fiber and each twisted optical fiber; the twisted optical fibers in each layer of twisted optical fibers are arranged in a circular ring shape, the gaps between the center optical fiber and the twisted optical fibers and the gaps between the twisted optical fibers in each optical fiber bundle unit are filled with polymer optical fiber coating, and the outer diameter of each layer of twisted optical fibers is equal to the corresponding twisted outer diameter.

2. The multicore jellyfish cable of claim 1, wherein, fiber bundle units in the fiber bundle structure are arranged in parallel to form a fiber bundle belt, and high-molecular fiber coating is used to connect adjacent fiber bundle units.

3. The multicore jellyfish cable of claim 1, wherein, The optical fiber bundle structure comprises a central optical fiber bundle unit and M layers of twisted optical fiber bundle units outside the central optical fiber bundle unit, M≥2, wherein the first layer of twisted optical fiber bundle units comprises 6 twisted optical fiber bundle units, and the first layer of twisted optical fiber bundle units are twisted together around the central optical fiber bundle unit at a twisting pitch Q1; the jth layer of twisted optical fiber bundle units comprises 6*j twisted optical fiber bundle units, and the jth layer of twisted optical fiber bundle units are twisted together around the (j-1)th layer of twisted optical fiber bundle units at a twisting pitch Qj j Qj+1 j satisfying , j ranges from 2 to M, M is the number of layers of the twisted optical fiber bundle units outside the central optical fiber bundle unit, and D is the diameter of the central optical fiber bundle unit and each twisted optical fiber bundle unit; the twisted optical fiber bundle units in each layer of twisted optical fiber bundle units are arranged in a circular ring shape, the gaps between the central optical fiber bundle unit and the twisted optical fiber bundle units and the gaps between the twisted optical fiber bundle units in the optical fiber bundle structure are filled with polymer optical fiber coating, and the outer diameter of each layer of twisted optical fiber bundle units is equal to the corresponding twisted outer diameter.

4. The multicore jellyfish cable of claim 1, wherein, The optical fiber bundle structure comprises a plurality of optical fiber bundle substructures, the plurality of optical fiber bundle substructures are arranged in parallel to form an optical fiber bundle belt, high polymer optical fiber coating is used to connect between adjacent optical fiber bundle substructures, each optical fiber bundle substructure comprises a central optical fiber bundle unit and M layers of twisted optical fiber bundle units located outside the central optical fiber bundle unit, M≥2, wherein the first layer of twisted optical fiber bundle unit comprises six twisted optical fiber bundle units, the first layer of twisted optical fiber bundle units are twisted together around the central optical fiber bundle unit with a twisting pitch Q1; the jth layer of twisted optical fiber bundle unit comprises 6*j twisted optical fiber bundle units, the jth layer of twisted optical fiber bundle units are twisted together around the (j-1)th layer of twisted optical fiber bundle unit with a twisting pitch Q j , Q j , Q , j is in the range of 2 to M, M is the number of layers of the twisted optical fiber bundle units outside the central optical fiber bundle unit, and D is the diameter of the central optical fiber bundle unit and each twisted optical fiber bundle unit; the twisted optical fiber bundle units in each layer of twisted optical fiber bundle units are arranged in a circular ring shape, the gaps between the central optical fiber bundle unit and the twisted optical fiber bundle units and the gaps between the twisted optical fiber bundle units in the optical fiber bundle structure are filled with high polymer optical fiber coating, and the outer diameter of each layer of twisted optical fiber bundle units is equal to the corresponding twisted outer diameter.

5. The multicore jellyfish cable of claim 2 or 3 or 4, wherein, The high-molecular fiber coating is ultraviolet curing resin or heat curing coating or thermoplastic material.

6. The multicore jellyfish cable of claim 2, wherein, The cable sheath is provided with reinforcing members, the number of the reinforcing members is four, the reinforcing members are arranged at four corner positions of the cable sheath respectively, and the wire laying tensile deformation of the reinforcing members is equal to the wire laying tensile deformation of each fiber bundle unit.

7. The multicore jellyfish cable of claim 2, wherein, The cable sheath is a butterfly-shaped cable sheath, the symmetric tear groove of the cable sheath is arranged at the center line position of the fiber bundle belt, and the opening is directed to the fiber bundle structure.

8. The multicore jellyfish cable of claim 3, wherein, The cable sheath is provided with reinforcing members, the number of the reinforcing members is two, and the reinforcing members are symmetrically arranged at two sides of the fiber bundle, and the wire laying tensile deformation of the reinforcing members is equal to the wire laying tensile deformation of each fiber bundle unit.

9. The multicore jellyfish cable of claim 3, wherein, The cable sheath is a butterfly-shaped cable sheath, and the opening of the symmetric tear groove of the cable sheath is directed to the fiber bundle structure.

10. The multicore jellyfish cable of claim 6 or 8, wherein, The reinforcing members are made of rigid glue-coated GFRP or glue-coated steel wire.

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