Device and method for preparing optical fiber core rod

Abstract

The present invention provides a device and method for preparing an optical fiber core rod, including: a bag extruder, an optical fiber guide tube and an optical fiber protective tube; a mouth-shaped body is provided at the head of the bag extruder; the core rod is inserted into the inner cavity of the mouth-shaped body, and an extrusion channel of a silicone rubber material is provided between the outer wall of the mouth-shaped body and the outer shell of the bag extruder head; a plurality of through grooves are provided on the wall surface of the mouth-shaped body close to the inner cavity along the circumferential direction for inserting optical fibers; there are multiple optical fiber guide tubes, each of which is inserted into the corresponding through groove along the axial direction and extends out of the two ends of the through groove; an optical fiber is inserted into the optical fiber protective tube, and the optical fiber protective tube is inserted into the optical fiber guide tube, so as to be tightly bonded to the outer wall of the core rod together with the sheath under the action of the extrusion force. The present invention realizes the effective fusion of the optical fiber, the core rod and the sheath by providing a plurality of through grooves on the wall surface of the mouth-shaped body of the bag extruder to insert the optical fiber, so as to fit the optical fiber to the surface of the core rod under the action of the extrusion force of the extruded sheath.

Description

Technical Field

[0001] The present invention relates to the technical field of composite insulators, and in particular to a device and method for preparing an optical fiber core rod. Background Art

[0002] Fiber-optic composite insulators are a type of composite insulator with optical signal transmission performance developed based on existing composite insulator technology. The difficulty in manufacturing it lies in how to implant the optical fiber into the composite insulator without generating interface gaps, so that the composite insulator still has a high level of electrical insulation and can ensure safe, long-term and reliable operation. At present, the fiber-optic embedding technologies adopted by various manufacturers are different, and the manufacturing process methods are diverse and different. Some use hollow core rods to introduce optical fibers and fill them with glue. Due to the differences in thermal expansion coefficients between the core rod, the potting glue or filling resin, and the optical fiber material, a certain degree of shrinkage will occur during the curing process of the potting glue or filling resin. This shrinkage effect will bring three hazards: a) bubbles or gaps will be generated between the interfaces inside the core rod, causing internal insulation defects; b) stress will be formed inside the core rod, resulting in increased fiber loss or even fiber breakage; c) relative rotation will occur after the glue layer solidifies, causing the optical fiber to twist or even break. Even if liquid gel is used for potting or filling, due to the lack of fluidity, its performance and state are easily affected by factors such as temperature, concentration, pressure, and expansion coefficient, and its stability is poor. It is also easy to produce internal insulation defects such as bubbles or gaps, and the manufacturing process and human factors are increased. Some grooves are dug on the outer wall of the core rod to embed the optical fiber in the core rod groove, which artificially destroys the glass fiber and resin inside the core rod, reduces the cross-sectional area of ​​the core rod that originally bears tensile strength, and reduces the mechanical tensile strength of the insulator, bringing risks and hidden dangers to safe use. Moreover, whether it is spiral grooving or linear grooving, it needs to be processed by milling machine or lathe, and the consistency of groove depth and groove width is difficult to control, especially for core rods with a length of more than 9m, the processing consistency is more difficult, and it is difficult to completely clean the groove and it is easy to leave dust, which brings hidden dangers of bubble defects to subsequent glue sealing. Obviously, the existing technologies have more or less problems of immature process and complex process, and are particularly prone to internal insulation and interface defects. Summary of the invention

[0003] In view of this, the present invention proposes a device and method for preparing an optical fiber core rod, aiming to solve the problem that internal insulation and interface defects are easily generated in the production and manufacturing of existing optical fiber composite insulators.

[0004] In one aspect, the present invention provides a device for preparing an optical fiber core rod, comprising: an extruder, an optical fiber guide tube and an optical fiber protection tube; wherein:

[0005] The head of the extruder is provided with a die-shaped body, which is used to guide the core rod and the silicone rubber material when extruding the sheath of the optical fiber core rod to be prepared; the core rod is inserted into the inner cavity of the die-shaped body, and an extrusion channel of the silicone rubber material is provided between the outer wall of the die-shaped body and the outer shell of the head of the extruder, which is used to make the silicone rubber material flow to the position to be formed on the outer wall of the core rod of the sheath when the silicone rubber material is extruded, so as to form the sheath;

[0006] A plurality of through grooves are provided on one side of the wall of the mouth-shaped body close to the inner cavity along the circumferential direction, and each of the through grooves is used to pass an optical fiber;

[0007] There are multiple optical fiber guide tubes, each of which is axially inserted into the corresponding through slot and extends out of both ends of the through slot;

[0008] An optical fiber is passed through the optical fiber protection tube, and the optical fiber protection tube passes through and extends out of the optical fiber guide tube, so as to be tightly bonded to the outer wall of the core rod together with the sheath under the action of extrusion force.

[0009] Furthermore, in the above-mentioned optical fiber core rod preparation device, the matching clearance between the optical fiber guide tube and the through groove is ≤0.02mm.

[0010] Furthermore, in the above-mentioned optical fiber core rod preparation device, the outer diameter of the optical fiber guide tube is 1.5-3 mm, and the wall thickness is 0.15-0.3 mm.

[0011] Furthermore, in the above-mentioned optical fiber core rod preparation device, the outer diameter of the optical fiber protection tube is smaller than that of the optical fiber guide tube.

[0012] Furthermore, in the above-mentioned optical fiber core rod preparation device, the outer diameter of the optical fiber protection tube is 0.5-1 mm, and the wall thickness is 0.05-0.15 mm.

[0013] Furthermore, in the above-mentioned optical fiber core rod preparation device, the inner walls of both ends of the optical fiber guide tube and the optical fiber protection tube are subjected to smooth transition treatment.

[0014] Furthermore, in the above-mentioned optical fiber core rod preparation device, a sealing structure is provided at the joint between the optical fiber protection tube and the optical fiber to fix the optical fiber and the optical fiber protection tube as a whole.

[0015] The optical fiber core rod preparation device provided by the present invention provides a plurality of through grooves on the wall surface of the mouth body of the extruder to pass the optical fiber guide tube, and passes the optical fiber into the optical fiber protection tube and then into the optical fiber guide tube, so that the optical fiber is tightly attached to the core rod surface under the action of the extrusion force of the extruded silicone rubber material, and the surface and the interior of the core rod do not need to be damaged or secondary processed, which fully ensures that the mechanical strength of the core rod is not damaged, realizes the effective fusion of the optical fiber, the core rod and the sheath, and there are no defects such as bubbles, gaps, and stratification between the three, optimizes the interface performance, improves the electrical strength, can realize the long-term safe and reliable operation of the optical fiber composite insulator, and is conducive to extending the service life of the optical fiber composite insulator.

[0016] On the other hand, the present invention also provides a method for preparing an optical fiber core rod, comprising the following steps:

[0017] A plurality of optical fiber guide tubes are axially arranged in correspondence with each through groove on the wall surface of the die body of the package extruder, and the die body is installed in the head of the package extruder;

[0018] Inserting the optical fiber protection tubes with optical fibers inserted into the optical fiber guide tubes one by one;

[0019] The core rod is passed through the mouth-shaped body along the inner cavity of the mouth-shaped body, and silicone rubber material is extruded on the surface of the core rod to form a sheath. During the extrusion of the silicone rubber material, the optical fiber protection tube is pulled out together with the optical fiber by the extrusion force and is tightly bonded to the outer wall of the core rod together with the formed sheath, thereby obtaining an optical fiber core rod.

[0020] Furthermore, the method for preparing the optical fiber core rod further comprises: after the sheath extrusion is completed, stripping the end sheath and ensuring that the stripped portion maintains a preset distance from the optical fiber protection tube.

[0021] Furthermore, in the method for preparing the optical fiber core rod, after the end sheath is stripped off, the extruded optical fiber core rod is baked at 140-160° C. for a period of time to completely vulcanize the sheath.

[0022] The preparation method of the optical fiber core rod of the present invention tightly bonds the silicone rubber sheath and the optical fiber to the core rod by extrusion, so that they are fully integrated into one, and can realize the smooth implantation of the optical fiber in the extrusion process state of the composite insulator, without affecting the normal production process of the composite insulator. From the perspectives of processability, economy and practicality, it better meets the production needs of the composite insulator, does not need to add additional production processes, and greatly improves the production efficiency; the optical fiber core rod realizes the effective fusion of the optical fiber, the core rod and the sheath, and there are no defects such as bubbles, gaps and stratification between the three, the interface performance is good, the electrical strength is high, and the optical fiber composite insulator can be operated safely and reliably for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0024] Figure 1 A schematic structural diagram of an optical fiber core rod preparation device provided by an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A partial enlarged view of the A' in the middle;

[0026] Figure 3 A schematic diagram of a partial structure of a package extruder head of an optical fiber core rod preparation device provided by an embodiment of the present invention;

[0027] Figure 4 A side view of a package extruder head of an optical fiber core rod preparation device provided by an embodiment of the present invention;

[0028] Figure 5 for Figure 4 A partial enlarged view of the middle A;

[0029] Figure 6 An assembly diagram of an optical fiber and a metal capillary in a method for preparing an optical fiber core rod provided in an embodiment of the present invention;

[0030] Figure 7 A schematic diagram of the position of stripping the sheath in the method for preparing an optical fiber core rod provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] See also Figures 1 to 7The optical fiber core rod preparation device of the embodiment of the present invention comprises: an extruder 1, an optical fiber guide tube 5 and an optical fiber protection tube 7; wherein the extruder 1 is provided with a mouth-shaped body 11 at the head thereof, which is used to guide the core rod and the silicone rubber material when the sheath 3 of the optical fiber core rod to be prepared is extruded; the core rod 2 is inserted into the inner cavity of the mouth-shaped body 11, and an extrusion channel H of the silicone rubber material is provided between the outer wall of the mouth-shaped body 11 and the outer shell 10 of the extruder head thereof, which is used to make the silicone rubber material flow when the silicone rubber material is extruded. The sheath 3 is formed on the outer wall of the core rod 2; a plurality of through grooves 4 are circumferentially formed on one side of the wall surface of the mouth-shaped body 11 close to the inner cavity, and each through groove 4 is used to pass an optical fiber 6; there are multiple optical fiber guide tubes 5, each of which is axially passed through the corresponding through groove 4 and extends out of the two ends of the through groove 4; an optical fiber 6 is passed through the optical fiber protection tube 7, and the optical fiber protection tube 7 passes through and extends out of the optical fiber guide tube 5, so as to Figure 1 and Figure 2 The direction of the arrow in the extrusion channel H is the direction of the extrusion force), and the sheath 3 is tightly bonded to the outer wall of the core rod 2.

[0033] Specifically, the extruder 1 is any optical fiber sheath extruder 1 having a mouth-shaped body 11 in the prior art. In the present embodiment, the mouth-shaped body 11 of the extruder 1 is improved, and the inner cavity of the mouth-shaped body 11 is used to guide the core rod 2; the outer wall of the mouth-shaped body 11 is conical to provide a guiding effect for the silicone rubber material. A plurality of axial through grooves 4 are provided on the wall surface of the mouth-shaped body 11 close to the inner cavity to place the optical fiber guide tube 5. The shape of the through groove 4 is adapted to the shape of the optical fiber guide tube 5. The wall surface of the through groove 4 is tangent to the portion of the inner cavity of the mouth-shaped body 11 of the extruder 1 close to the inner wall (such as Figure 4-5 As shown in FIG. 1 ), the optical fiber 6 is smoothly pulled out to the surface of the core rod 2, thereby ensuring close contact without gaps between the optical fiber 6, the core rod 2 and the sheath 3. In practice, the optical fiber guide tube 5 can be a stainless steel tube.

[0034] A plurality of optical fiber guide tubes 5 may be provided, which are consistent with the number of through slots 4 and are provided to pass through the through slots 4 for a certain distance; more specifically, three optical fiber guide tubes 5 are provided, and correspondingly, three through slots 4 are provided along the circumferential direction, and the three through slots 4 are evenly distributed along the circumferential direction at intervals of 120°, dividing the end face of the mouth-shaped body 11 into three equal parts (such as Figure 3 The cross-sectional view shows that an optical fiber guide tube 5 is respectively passed through two of the through grooves, that is, each optical fiber guide tube 5 is evenly embedded in each through groove 4 on the wall surface of the mouth-shaped body 11. In practice, the optical fiber guide tube 5 can pass through the two ends of the through groove 4, that is, the end surface of the mouth-shaped body 11 by about 1 mm.

[0035] In actual application, the matching clearance between the optical fiber guide tube 5 and the through groove 4 is ≤0.02 mm.

[0036] Furthermore, combined with Figure 1 and Figure 3 The outer diameter of the optical fiber guide tube 5 is 1.5-3 mm, preferably 2 mm ± 0.5 mm, and the wall thickness is 0.15-0.3 mm, preferably 0.2 m ± 0.05 mm. The length of the optical fiber guide tube 5 can be determined according to the specifications and quantity of the optical fiber composite insulator product to be prepared, for example, it can be 500 m ± 1 mm.

[0037] Continue to combine Figure 1 , Figure 6 and Figure 7 The optical fiber protection tube 7 is a metal capillary. Obviously, the outer diameter of the optical fiber protection tube 7 is smaller than that of the optical fiber guide tube 5. One optical fiber protection tube 7 is inserted into each optical fiber guide tube 5.

[0038] It should be noted that Figure 6 The equal lines in the figure are the cut-off lines of the optical fiber 6 and the optical fiber protection tube 7, and the long and short lines are the cut-off lines of the optical fiber 6.

[0039] In this embodiment, one or more optical fibers 6 may be inserted into each optical fiber protection tube 7, and the number of optical fibers 6 may be determined according to actual conditions, for example, three or more optical fibers 6 of equal length may be selected, and the length of each optical fiber 6 is greater than the length of the core rod 2. Since the optical fiber 6 is too thin and easily displaced, the optical fiber 6 is inserted out of the optical fiber protection tube 7 by a preset length to confirm that the optical fiber 6 is inserted into the optical fiber protection tube 7. The length of the optical fiber 6 inserted out of the optical fiber protection tube 7 may be determined according to actual conditions, for example, the optical fiber may be inserted out of the end of the optical fiber protection tube 7 by 300 mm.

[0040] More specifically, the outer diameter of the optical fiber protection tube 7 is 0.5-1mm, preferably 1mm±0.2mm; the wall thickness is 0.05-0.15mm, preferably 0.1mm±0.05mm. The length of the optical fiber protection tube 7 can be determined according to the specifications and quantity of the optical fiber 6 composite insulator product to be prepared, for example, it can be 600m±1mm.

[0041] In this embodiment, a sealing structure (not shown in the figure) is provided at the joint between the optical fiber protection tube 7 and the optical fiber 6 to fix the optical fiber 6 and the optical fiber protection tube 7 as a whole, enhance the stability of the joint, and ensure the quality and safety of signal transmission. The sealing structure can be sealing wax, which can effectively prevent moisture from intruding and protect the optical fiber 6 from damage. In addition, the use of sealing wax is relatively simple, and a uniform sealing layer can be formed at the joint between the optical fiber protection tube 7 and the optical fiber 6, further enhancing the waterproof and dustproof performance of the joint.

[0042] Specifically, at least one end of the optical fiber protection tube 7 is provided with a sealing structure. The sealing structure may be sealing wax. Figure 6In practice, the optical fiber protection tube 7 can be divided into sections and separated according to the needs of optical fiber core rod products of different lengths, so as to pass optical fibers 6 of different lengths, thereby improving production efficiency.

[0043] In a specific implementation, after the optical fiber 6 passes through the optical fiber protection tube 7 for a certain distance, at the joint between the optical fiber protection tube 7 and the optical fiber 6 (for example Figure 6 The optical fiber 6 and the optical fiber protection tube 7 are sealed with wax at points D and E in the figure.

[0044] In this embodiment, in order to facilitate and quickly insert the optical fiber protection tube 7 into the optical fiber guide tube 5 and reduce the friction between the optical fiber protection tube 7 and the optical fiber 6, the inner walls of both ends of the optical fiber guide tube 5 and the optical fiber protection tube 7 are smoothed.

[0045] In this embodiment, the core rod 2 is a solid pultruded rod, and the surface and interior of the core rod 2 do not need to be damaged or reprocessed, which fully ensures that the mechanical strength of the core rod 2 is not damaged.

[0046] It can be obviously concluded from the above that the preparation device of the optical fiber core rod provided in this embodiment, by opening a plurality of through grooves on the wall surface of the mouth body of the extruder to pass the optical fiber guide tube, and by passing the optical fiber into the optical fiber protection tube and then into the optical fiber guide tube, so that under the action of the extrusion force of the extruded silicone rubber material, the optical fiber is tightly attached to the surface of the core rod, and the surface and the interior of the core rod do not need to be damaged or secondary processed, which fully ensures that the mechanical strength of the core rod is not destroyed, realizes the effective fusion of the optical fiber, the core rod, and the sheath, and there are no defects such as bubbles, gaps, and stratification between the three, optimizes the interface performance, improves the electrical strength, can realize the long-term safe and reliable operation of the optical fiber composite insulator, and is conducive to extending the service life of the optical fiber composite insulator.

[0047] The present invention also provides a method for preparing an optical fiber core rod, comprising the following steps:

[0048] Step S1, a plurality of optical fiber guide tubes 5 are axially arranged in correspondence with each through groove on the wall surface of the die body of the package extruder, and the die body is installed into the head of the package extruder.

[0049] In the specific implementation, a plurality of through grooves 4 are opened along the circumferential direction on the wall surface of the die-shaped body at the head of the extruder near the inner cavity. After the through grooves 4 on the inner wall of the die-shaped body 12 are processed, a metal rod can be used to tap the portion where the end surface of the die-shaped body and the wall surface of the through grooves 4 are tangent ( Figure 5 The through groove 4 is slightly deformed to hold the optical fiber guide tube 5 in place.

[0050] Combination Figure 1Before extruding the sheath 3, insert the optical fiber protection tube 7 with a plurality of optical fibers 6 into the optical fiber guide tube 5 from the B end of the extended optical fiber guide tube 5, until the optical fiber protection tube 5 can be seen from the C end to extend more than 10 mm from the end of the mouth-shaped body 11, and then pass the core rod 2 through the inner cavity of the mouth-shaped body 11 in the head of the extruder.

[0051] Step S2, inserting the optical fiber protection tubes with optical fibers inserted into the optical fiber guide tubes 5 one by one.

[0052] Step S3, passing the core rod through the mouth-shaped body 11 along the inner cavity of the mouth-shaped body, and extruding silicone rubber material on the surface of the core rod 2 to form a sheath 3. During the extrusion of the silicone rubber material, the optical fiber protection tube 7 is pulled out together with the optical fiber 6 by the extrusion force and tightly adhered to the outer wall of the core rod 2 together with the formed sheath 3, thereby obtaining an optical fiber core rod.

[0053] Combination Figure 1 and Figure 2 The extrusion force drives the flow of the silicone rubber, and as the silicone rubber flows, the optical fiber protection tube together with the optical fiber is pulled out and tightly bonded to the outer wall of the core rod together with the silicone rubber sheath.

[0054] Combination Figure 7 In the above embodiment, it also includes: after the sheath is extruded, the end sheath is peeled off, and it is ensured that the peeled position maintains a preset distance (the distance indicated by d in the figure) with the optical fiber protection tube.

[0055] In the specific implementation, the lower cutter of the peeling sheath ( Figure 7 The distance between the end face of the optical fiber protection tube 7 and the middle G position is about 5 mm to avoid damaging the optical fiber 6, that is, the unevenly squeezed sheaths 3 at both ends of the core rod 2 are peeled off.

[0056] Furthermore, after the end sheath 3 is stripped off, the extruded optical fiber core rod is baked at 140-160° C. for a period of time to completely vulcanize the sheath 3.

[0057] In a specific implementation, the extruded optical fiber core rod may be preferably baked at 150° C. for 5 hours to completely vulcanize the sheath.

[0058] Combine the following Figure 1 , Figure 2 , Figure 6 and Figure 7 , the present invention is described in detail with a specific embodiment:

[0059] Before extruding the sheath, three optical fiber protection tubes 7 with optical fibers 6 are inserted into the optical fiber guide tube 5 from the B end of the extended optical fiber guide tube 5 until the optical fiber protection tube 7 can be seen to extend more than 10mm from the end of the mouth-shaped body 11 from the C end; then the core rod 2 is passed through the inner cavity of the mouth-shaped body 11 in the head of the extruder; the extruder is started to extrude the sheath 3, and the extrusion force drives the silicone rubber material to flow. With the flow of the silicone rubber material, the optical fiber 6 and the optical fiber protection tube 7 are also pulled out and tightly bonded to the outer wall of the core rod 2 together with the silicone rubber sheath 3; after the extrusion is completed, the end sheath 3 is peeled off, and it is noted that the lower knife position is about 5mm away from the end of the optical fiber protection tube to avoid damaging the optical fiber 6. The extruded core rod sheath 3 is placed in a drying room at 150℃±5℃ for 5h±0.5h to completely vulcanize the sheath to obtain an insulating core rod 2 with an optical fiber sheath.

[0060] It should be noted that the method for preparing an extruded optical fiber rod according to the embodiment of the present invention is not only applicable to core rods of all specifications with a diameter ≥ φ16 mm, but also applicable to core rods with a diameter below 16 mm, and has a wide range of applicability.

[0061] The related parts of the method embodiment and the above-mentioned device embodiment can be referred to each other and will not be described in detail here.

[0062] In summary, the present invention has the following beneficial effects:

[0063] 1. The silicone rubber sheath and the optical fiber are tightly bonded to the core rod by extrusion, so that they are fully integrated into one, which can realize the smooth implantation of the optical fiber in the composite insulator extrusion process state, without affecting the normal production process of the composite insulator. From the perspective of processability, economy and practicality, it can better meet the production needs of the composite insulator, without adding additional production processes, and greatly improves the production efficiency;

[0064] 2. The optical fiber core rod realizes the effective fusion between the optical fiber, core rod and sheath. There are no defects such as bubbles, gaps, and delamination between the three. The interface performance is good and the electrical strength is high, which can realize the long-term safe and reliable operation of the optical fiber composite insulator;

[0065] 3. Through the process of extruding the sheath, the optical fiber can be attached to the surface of the core rod for extrusion without changing the original process steps and parameters, and without processing the surface of the core rod, which is beneficial to improving the operating reliability of the optical fiber composite insulator and extending its service life.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A device for preparing an optical fiber core rod, characterized in that: include: Extrusion machine, optical fiber guide tube and optical fiber protection tube; wherein, The extruder is provided with a die-shaped body at the head of the extruder, which is used to extrude the sheath of the optical fiber core rod to be prepared into the core rod and the silicon The mandrel is inserted into the inner cavity of the die-shaped body, and an extrusion channel for the silicone rubber material is provided between the outer wall of the die-shaped body and the outer shell of the extruder head, so as to make the silicone rubber material flow to the position to be formed of the sheath on the outer wall of the mandrel when the silicone rubber material is extruded, so as to form the sheath; A plurality of through grooves are provided on the side of the wall of the mouth-shaped body close to the inner cavity along the circumferential direction, each of which is used to pass a light The wall of the through groove is tangent to the inner wall of the inner cavity of the die body of the extruder; There are multiple optical fiber guide tubes, each of which is axially inserted into the corresponding through slot and extends out two ends of the through slot; The optical fiber protection tube is provided with an optical fiber, and the optical fiber protection tube is provided through and extends out of the optical fiber guide tube. Under the action of extrusion force, the sheath is tightly bonded to the outer wall of the core rod.

2. The optical fiber core rod preparation device according to claim 1, characterized in that: The matching clearance between the optical fiber guide tube and the through groove is ≤0.02mm.

3. The optical fiber core rod preparation device according to claim 1, characterized in that: The outer diameter of the optical fiber guide tube is 1.5-3 mm, and the wall thickness is 0.15-0.3 mm.

4. The optical fiber core rod preparation device according to claim 1, characterized in that: The outer diameter of the optical fiber protection tube is smaller than that of the optical fiber guide tube.

5. The optical fiber core rod preparation device according to claim 1, characterized in that: The outer diameter of the optical fiber protection tube is 0.5-1 mm, and the wall thickness is 0.05-0.15 mm.

6. The optical fiber core rod preparation device according to claim 1, characterized in that: The inner walls of both ends of the optical fiber guide tube and the optical fiber protection tube are processed with smooth transition.

7. The optical fiber core rod preparation device according to claim 1, characterized in that: A sealing structure is provided at the joint between the optical fiber protection tube and the optical fiber, so as to fix the optical fiber and the optical fiber protection tube as a whole.

8. A method for preparing an optical fiber core rod using the optical fiber core rod preparation device according to claim 1, characterized in that: The following steps are involved: A plurality of optical fiber guide tubes are axially arranged in correspondence with each through groove on the wall surface of the die body of the extruder, and the die body is The mold body is loaded into the die head of the extruder; the wall surface of the through groove is tangent to the inner wall of the inner cavity of the mold body of the extruder die; Inserting the optical fiber protection tubes with optical fibers inserted into the optical fiber guide tubes one by one; The mandrel is passed through the mouth-shaped body along the inner cavity of the mouth-shaped body, and the silicone rubber material is extruded on the surface of the mandrel to form During the extrusion of the silicone rubber material, the optical fiber protection tube is pulled out together with the optical fiber by the extrusion force and is tightly bonded to the outer wall of the core rod together with the formed sheath, thereby obtaining the optical fiber core rod.

9. The method for preparing an optical fiber core rod according to claim 8, characterized in that: Also includes: After the sheath is extruded, the end sheath is peeled off, and it is ensured that the peeled portion maintains a preset distance from the optical fiber protection tube.

10. The method for preparing an optical fiber core rod according to claim 9, characterized in that: After the end sheath is stripped off, the extruded optical fiber core rod is baked at 140-160° C. for a period of time to completely vulcanize the sheath.

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