Sensing optical fiber splicing process suitable for optical fiber winding structure

Abstract

The invention discloses a sensing optical fiber splicing process suitable for an optical fiber winding structure, which comprises the following steps of: changing a winding pitch, slotting, welding and fixing, in the process of winding a sensing optical fiber on the surface of a sensibilization layer of a cable core, when the sensing optical fiber is about to reach the central position of a planned splicing area, gradually increasing the pitch, the method comprises the following steps: forming a loose transition section of a sensing optical fiber, grooving the surface of a sensitization layer on a planned splicing area of a cable core to form a splicing groove, sleeving a heat shrink tube on the end part of the sensing optical fiber, and then performing end part welding with another sensing optical fiber to be spliced. The sensing optical fiber is fixed at the starting end and the terminating end of the connection groove in a point-like manner through the adhesive, so that the connection of the sensing optical fiber is realized, the reliability of the connection point is improved, the welding loss is reduced, and the continuous manufacturing of the ultra-long section communication sensing integrated submarine cable is met.

Description

Technical Field

[0001] This invention relates to the field of optical cable manufacturing, and in particular to a sensing fiber splicing process suitable for optical fiber winding structures. Background Technology

[0002] With the large-scale application of integrated communication and sensing submarine cables, higher requirements have been placed on the length of a single integrated communication and sensing submarine cable, necessitating the continuous manufacturing of ultra-long sections of integrated communication and sensing submarine cables spanning tens of kilometers.

[0003] In the continuous industrial production of integrated communication and sensing submarine cables, splicing of sensing optical fibers is necessary due to process limitations or unexpected interruptions. Existing technology includes a method for splicing underground optical cables, disclosed in patent application CN115774303A, which involves splicing and coating the communication optical fibers within the inner steel tube. However, in integrated communication and sensing submarine cables, in addition to the communication optical fibers in the cable core, there are also sensing optical fibers. Since the sensing optical fibers are wound around the surface of the sensitivity-enhancing layer of the cable core, the difficulty of online splicing is increased, requiring improvement. Summary of the Invention

[0004] The main technical problem solved by this invention is to provide a sensing fiber splicing process suitable for optical fiber winding structures, realize the splicing of sensing fibers, improve splicing reliability, and meet the continuous manufacturing requirements of ultra-long-span integrated communication and sensing submarine cables.

[0005] To solve the above-mentioned technical problems, one technical solution adopted by the present invention is to provide a sensing fiber splicing process suitable for fiber optic winding structures, comprising the following steps:

[0006] S01. Change the winding pitch:

[0007] During the process of winding the sensing fiber (2) on the surface of the sensitive layer of the cable core (1), the working pitch of the winding is set to P1. When the center position of the planned splice area is about to be reached, the pitch is gradually increased, and the splice area pitch of the winding is set to P2, and P2 is greater than P1, forming a relaxed transition section of the sensing fiber (2).

[0008] S02, Grooving:

[0009] On the splicing area planned in the cable core (1), the surface of the sensitivity enhancement layer is grooved to form a splicing groove (4). The starting and ending ends of the splicing groove (4) are chamfered to create a gentle slope area, which buffers the entry and exit of the sensing fiber (2) into and out of the splicing groove (4) to avoid excessive strain.

[0010] S03, Welding:

[0011] Take the sensing fiber (2) out of the winding path, put the heat shrink tube (3) on the end, and then perform end splicing with another sensing fiber that needs to be connected. The splicing loss is <0.1dB.

[0012] Push the heat shrink tubing (3) to the welding area and perform heat shrinking treatment;

[0013] S04, Fixed:

[0014] The heat shrink tubing (3) is placed in the splice slot (4), and the sensing optical fibers (2) at both ends of the heat shrink tubing (3) are arranged in a sinusoidal pattern in the splice slot (4). This waveform design ensures that the sensing optical fibers (2) have sufficient margin in the splice slot (4).

[0015] The sensing fiber (2) is fixed in a dotted manner at the beginning and end of the splice groove (4) by adhesive.

[0016] In a preferred embodiment of the present invention, the working pitch P1 ranges from 20mm to 60mm, and the splicing pitch P2 ranges from 150mm to 250mm.

[0017] In a preferred embodiment of the present invention, in step S01, the winding length of the sensing fiber (2) is monitored by a meter counter.

[0018] In a preferred embodiment of the present invention, in step S02, the grooving is performed using a CNC thermal cutting machine. The temperature of the cutting head of the CNC thermal cutting machine is controlled between 200°C and 300°C. The high-temperature cutting head melts and removes the material on the sensitive layer to form a connecting groove (4).

[0019] In a preferred embodiment of the present invention, the connecting groove (4) adopts a spindle-shaped structure.

[0020] In a preferred embodiment of the present invention, the heat shrink tube (3) is 40 mm long, and before heat shrinking, the sensing optical fiber (2) is initially bonded to the heat shrink tube (3) using shadowless adhesive.

[0021] In a preferred embodiment of the present invention, the adhesive is a hot melt adhesive.

[0022] In a preferred embodiment of the present invention, step S05, restoring the working pitch, is further included:

[0023] After the connection is completed, continue winding the sensing fiber and gradually reduce the pitch until the pitch is restored to the working pitch P1, and then perform normal winding.

[0024] In a preferred embodiment of the present invention, the length of the splicing area is 1.0m to 2.0m.

[0025] In a preferred embodiment of the present invention, step S06, wrapping:

[0026] After the sensing fiber (2) is wound on the surface of the sensitizing layer, the outer side of the sensing fiber (2) is wrapped with water-blocking tape to achieve the binding of the heat shrink tube (3).

[0027] The beneficial effects of this invention are: the sensing fiber splicing process applicable to optical fiber winding structures pointed out in this invention can realize the splicing of sensing fibers, improve the reliability of splicing points, reduce fusion splicing loss, meet the continuous manufacturing of ultra-long communication and sensing integrated submarine cables, effectively ensure the smoothness of production, and improve the product qualification rate. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of 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, wherein:

[0029] Figure 1 This is a schematic diagram of a preferred embodiment of a sensing fiber splicing process applicable to fiber optic winding structures according to the present invention. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figure 1 The embodiments of the present invention include:

[0032] A sensing fiber splicing process suitable for fiber optic winding structures includes the following steps:

[0033] S01. Change the winding pitch:

[0034] During the process of winding the sensing fiber (2) onto the surface of the sensitive layer of the cable core (1), the working pitch of the winding is set to P1. When the center position of the planned splice area is about to be reached, the pitch is gradually increased, and the pitch of the splice area is set to P2, and P2 is greater than P1. The pitch can be changed by a CNC winding machine. The CNC winding machine has an online pitch program switching function and a tension control accuracy of ±3%.

[0035] In this embodiment, the working pitch P1 ranges from 20mm to 60mm, and the splicing pitch P2 ranges from 150mm to 250mm, forming a relaxed transition section of the sensing fiber (2) and creating a low-stress splicing space.

[0036] The problem of splicing of sensing optical fibers due to process limitations can be solved by monitoring the winding length of sensing optical fiber (2) with a meter counter and automatically planning the splicing area where two sensing optical fibers need to be fused together.

[0037] S02, Grooving:

[0038] On the splicing area planned in the cable core (1), the surface of the sensitizing layer is grooved to form a splicing groove (4). The sensitizing layer can be made of TPU acoustic coupling material, and the thickness is usually 2~3mm.

[0039] In this embodiment, the grooving is performed using a CNC thermal cutting machine. The temperature of the cutting head of the CNC thermal cutting machine is controlled between 200°C and 300°C. The high-temperature cutting head melts and removes the material on the sensitive layer to form a continuous groove (4).

[0040] like Figure 1 As shown, the splice groove (4) adopts a spindle-shaped structure. Specifically, the splice groove (4) is 80~100mm long, 8~10mm wide in the middle, and 2~3mm deep, which facilitates subsequent construction. The starting and ending ends of the splice groove (4) are chamfered to create a gentle slope area, which buffers the entry and exit of the sensing fiber (2) into and out of the splice groove (4) to avoid excessive strain.

[0041] S03, Welding:

[0042] Take the sensing fiber (2) out of the winding path, put the heat shrink tube (3) on the end, and then perform end splicing with another sensing fiber that needs to be connected. The splicing loss is <0.1dB.

[0043] The heat shrink tube (3) is pushed to the fusion area for heat shrinking treatment to strengthen the protection of the fusion point. In this embodiment, the heat shrink tube (3) is 40mm long. Before heat shrinking, the sensing fiber (2) and the heat shrink tube (3) are initially bonded with shadowless glue, which has high stability and avoids relative slippage of the heat shrink tube (3) during the heat shrinking process.

[0044] S04, Fixed:

[0045] The heat shrink tubing (3) is placed in the splice slot (4), and the sensing optical fibers (2) at both ends of the heat shrink tubing (3) are arranged in a sinusoidal pattern in the splice slot (4). This waveform design ensures that the sensing optical fibers (2) have sufficient margin in the splice slot (4).

[0046] The sensing fiber (2) is fixed in a dotted manner at the beginning and end of the splice slot (4) by an adhesive. The adhesive is a hot melt adhesive, which is convenient for construction and avoids the detachment of the sensing fiber (2) at the beginning and end of the splice slot (4).

[0047] Step S05: Restore working pitch:

[0048] After the splicing is completed, continue winding the sensing fiber and gradually reduce the pitch until the pitch is restored to the working pitch P1, and then perform normal winding. In this embodiment, the length of the entire splicing area is 1.0m~2.0m to achieve a smooth transition of pitch change and ensure the convenience of fusion splicing operation.

[0049] Step S06, Wrapping the package:

[0050] After the sensing fiber that needs to be spliced ​​is completed and wound on the surface of the sensitizing layer, the sensing fiber (2) is wrapped with water-blocking tape to bind the heat shrink tube (3), which improves the reliability of the splice point and strengthens the water-blocking effect.

[0051] In summary, the present invention discloses a sensing fiber splicing process suitable for optical fiber winding structures, which realizes the splicing of sensing fibers, reduces splice loss, improves splice reliability, meets the requirements of continuous winding processing of long optical fibers, breaks through the limitations of long-length winding production of optical fibers, and adopts a low-stress structure process of pitch transformation and slotted fiber capacity, which has no adverse effect on cable production, and realizes the continuous production of over 50km integrated communication and sensing submarine cables.

[0052] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A sensing fiber splicing process suitable for fiber optic winding structures, characterized in that, Includes the following steps: S01. Change the winding pitch: During the process of winding the sensing fiber (2) onto the surface of the sensitive layer of the cable core (1), the working pitch of the winding is set to P1. When the center position of the planned splice area is about to be reached, the pitch is gradually increased and the splice area pitch is set to P2, and P2 is greater than P1. S02, Grooving: On the splicing area planned in the cable core (1), the surface of the sensitive layer is grooved to form a splicing groove (4). The starting and ending ends of the splicing groove (4) are chamfered to create a gentle slope area. S03, Welding: Take the sensing fiber (2) out of the winding path, put the heat shrink tube (3) on the end, and then perform end splicing with another sensing fiber that needs to be connected. Push the heat shrink tubing (3) to the welding area and perform heat shrinking treatment; S04, Fixed: The heat shrink tubing (3) is placed in the splice groove (4), and the sensing optical fibers (2) at both ends of the heat shrink tubing (3) are distributed in a sinusoidal pattern in the splice groove (4). The sensing fiber (2) is fixed in a dotted manner at the beginning and end of the splice groove (4) by adhesive.

2. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, The working pitch P1 ranges from 20mm to 60mm, and the splicing pitch P2 ranges from 150mm to 250mm.

3. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, In step S01, the winding length of the sensing fiber (2) is monitored by a meter counter.

4. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, In step S02, grooving is performed using a CNC thermal cutting machine, and the cutting head temperature of the CNC thermal cutting machine is controlled between 200℃ and 300℃.

5. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, The connecting groove (4) adopts a spindle-shaped structure.

6. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, The heat shrink tube (3) is 40mm long. Before heat shrinking, the sensing fiber (2) and the heat shrink tube (3) are initially bonded together using shadowless adhesive.

7. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, The adhesive used is a hot melt adhesive.

8. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, It also includes step S05, restoring the working pitch: After the connection is completed, continue winding the sensing fiber and gradually reduce the pitch until the pitch is restored to the working pitch P1, and then perform normal winding.

9. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, The length of the splicing zone is 1.0m to 2.0m.

10. The sensing fiber splicing process applicable to fiber optic winding structures according to claim 1, characterized in that, It also includes step S06, wrapping the package: After the sensing fiber (2) is wound on the surface of the sensitizing layer, the outer side of the sensing fiber (2) is wrapped with a water-blocking tape.

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