Sealed optical fiber penetrating device and preparation method thereof

Abstract

The invention relates to the technical field of penetration sealing, and provides a sealed optical fiber penetration device, which comprises a metal protective sleeve, a plastic sealing element and a plurality of metal capillary tubes, the metal protective sleeve is in sealed connection with a sealed boundary shell, the plastic sealing element is matched with the inner wall of the metal protective sleeve, a plurality of through holes are formed in the plastic sealing element, and the metal capillary tubes are arranged in the through holes. The metal capillary tube is arranged in the through hole in a penetrating mode. The metal capillary tube, the plastic sealing piece and the metal protection sleeve are tightly attached through rolling. The optical fiber penetrates through the metal capillary tube and is in sealed connection with the metal capillary tube. According to the invention, the sealing performance and the mechanical protection performance are guaranteed, the mechanical damage to the optical fiber in the manufacturing process is greatly reduced, the technological process is simplified, and the operation is convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of through-sealing, and more particularly to a sealed optical fiber through-device and a preparation method thereof. Background Art

[0002] The optical fiber through-device is an important functional component of the optical fiber through-piece, used to achieve the connection and optical signal transmission inside and outside the nuclear reactor containment. Due to the special working conditions, in order to ensure the continuity of the optical signal, maintain the integrity of the pressure boundary and prevent the leakage of reaction substances, etc., the optical fiber through-device has high sealing requirements.

[0003] Currently, structures such as welding and potting are often used to ensure pressure resistance, heat aging resistance, radiation aging resistance and sealing performance. For example, a patent with the publication number "CN213986950U" discloses an optical fiber through-device, including a through-pipe, with base flanges provided at both ends, and the through-flange is connected to the base flange; the through-flange forms a plurality of optical fiber access holes, and multiple energy optical fibers sequentially pass through the corresponding optical fiber access holes, and a sealing component is provided between the energy optical fiber and the optical fiber access hole. The outer part of all the energy optical fibers extending out of the sealing component is sleeved with the same optical fiber protection tube, and vacuum sealant is filled at the assembly gap to ensure the airtightness between the two penetrated areas.

[0004] However, in this prior art, there are no effective mechanical protection and sealing measures for single optical fibers inside the device, and damage is likely to occur during the installation process; moreover, a series of components such as base flanges and through-flanges are used and there are multiple dimensional fits, resulting in a large number of components and relatively complex installation, which limits the manufacturing efficiency and quality. Summary of the Invention

[0005] The purpose of the present invention is to provide a sealed optical fiber through-device and a preparation method thereof to solve the above-mentioned defects of the prior art.

[0006] The present invention is achieved through the following technical solutions:

[0007] A sealed optical fiber through-device includes a metal protection sleeve, which is hermetically connected to a sealed boundary housing, and also includes a plastic seal and a plurality of metal capillary tubes. The plastic seal cooperates with the inner wall of the metal protection sleeve. The plastic seal is provided with a plurality of through-holes, and the metal capillary tubes are inserted through the through-holes. The metal capillary tubes, the plastic seal and the metal protection sleeve are tightly fitted through rolling; an optical fiber is inserted through the metal capillary tube, and the optical fiber is hermetically connected to the metal capillary tube.

[0008] Optionally, a first thermosetting sealing material is filled between the optical fiber and the metal capillary tube.

[0009] Optionally, sealing holes are provided at both ends of the metal capillary tube, and a sealing structure is provided in the sealing holes.

[0010] Optionally, the sealing structure includes a second thermosetting sealing material, which is poured into the sealing hole.

[0011] Optionally, the sealing structure includes a glass solder, which is welded to the optical fiber and the metal capillary.

[0012] Optionally, the sealing structure includes a compression nut and a first sealing ring. The compression nut is threadedly connected to the sealing hole, and the first sealing ring is compressed between the compression nut and the bottom of the sealing hole.

[0013] Optionally, the metal capillary and the metal protective sleeve are made of stainless steel; the plastic seal is made of polysulfone, polyetheretherketone, polyethersulfone or polyimide.

[0014] Optionally, the metal protective sleeve is connected to the sealing boundary housing through a sealing assembly. The sealing assembly includes a sealing flange and a second sealing ring. The metal protective sleeve penetrates through the sealing boundary housing. The sealing flange is connected to the sealing boundary housing by screws, and the sealing flange presses the second sealing ring between the sealing boundary housing and the metal protective sleeve.

[0015] Optionally, the metal protective sleeve is welded to the sealing boundary housing.

[0016] The present invention also provides a method for manufacturing a sealed optical fiber penetration device for manufacturing the above-mentioned sealed optical fiber penetration device, including the following steps:

[0017] S1. Assemble the metal capillary, the plastic seal and the metal protective sleeve together and adjust the relative positions among the three.

[0018] S2. Put the assembled and position-adjusted metal capillary, plastic seal and metal protective sleeve as a whole into a rolling machine, and repeatedly roll them to meet the target dimension requirements, so as to form a tight fit among the three.

[0019] S3. Fill each metal capillary with a first thermosetting sealing material, and insert the optical fiber into the metal capillary.

[0020] S4. After the optical fiber penetrates through the metal capillary, set a sealing structure in the sealing hole of the metal capillary.

[0021] S5. Peel off the outer layer of the optical fiber and connect it to the connector to complete the manufacture of the sealed optical fiber penetration device.

[0022] The technical solution of the present invention has at least the following advantages and beneficial effects: In the present invention, a metal capillary is used to protect each optical fiber, and at the same time, the metal capillary, the plastic seal and the metal protection sleeve are integrally rolled to achieve tight fitting of the three, ensuring the sealing performance and mechanical protection performance; moreover, it is convenient to perform optical fiber core threading and sealing after the metal capillary, the plastic seal and the metal protection sleeve are integrally formed, greatly reducing the mechanical damage to the optical fiber during the manufacturing process, simplifying the process flow and facilitating operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 FIG. is a schematic structural diagram of a sealed optical fiber penetration device provided in Embodiment 1;

[0024] Figure 2 FIG. is a schematic structural diagram of the seal inside the seal hole in Embodiment 1;

[0025] Figure 3 FIG. is a schematic cross-sectional view of the seal perpendicular to the axis direction;

[0026] Figure 4 FIG. is a flowchart of a preparation method of a sealed optical fiber penetration device provided in Embodiment 1;

[0027] Figure 5 FIG. is a schematic structural diagram of the seal inside the seal hole in Embodiment 2;

[0028] Figure 6 FIG. is a schematic structural diagram of the seal inside the seal hole in Embodiment 3;

[0029] Figure 7 FIG. is a schematic structural diagram of a sealed optical fiber penetration device provided in Embodiment 4;

[0030] Reference numerals: 1 - optical fiber, 2 - metal capillary, 3 - seal, 301 - through hole, 4 - metal protection sleeve, 5 - seal flange, 6 - second sealing ring, 7 - second thermosetting sealing material, 8 - glass solder, 9 - compression nut, 10 - first sealing ring, 11 - seal boundary housing, 12 - limiting block, 13 - compression ring, 14 - first metal capillary protection tube, 15 - organic glue, 16 - second metal capillary protection tube. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Refer to Figure 1 , a sealed optical fiber penetration device includes a metal protection sleeve 4. In practical applications, after the sealed optical fiber penetration device and the optical fiber 1 are assembled, the whole is fixed through the metal protection sleeve 4 and the seal boundary housing 11, and a sealed connection is formed. As an option, the sealing connection method between the metal protection sleeve 4 and the seal boundary housing 11 in this embodiment is welding. The metal protection sleeve 4 is welded and fixed to the seal boundary housing 11 to form a seal.

[0032] In this embodiment, the sealed optical fiber penetration device further includes a plastic seal 3 and a plurality of metal capillary tubes 2. The optical fiber 1 is disposed inside the metal capillary tube 2, and is hermetically connected between the optical fiber 1 and the metal capillary tube 2, that is, each optical fiber 1 is protected by a metal capillary tube. The plastic seal 3 cooperates with the inner wall of the metal protective sleeve 4, and a plurality of through holes 301 are provided on the plastic seal 3 (refer to Figure 3 ). The metal capillary tube 2 is disposed inside the through hole 301. Similarly, the outer wall of the metal capillary tube 2 cooperates with the inner wall of the through hole 301. As an option, in this embodiment, there are two plastic seals 3, which are respectively disposed at both ends of the metal protective sleeve 4. After the metal capillary tube 2, the plastic seal 3 and the metal protective sleeve 4 are assembled together, the three are formed into an integral structure by repeated rolling, realizing a tight fit, ensuring the sealing performance and the mechanical protection performance. Moreover, it is convenient to perform core threading and sealing of the optical fiber 1 after the integral forming of the metal capillary tube 2, the plastic seal 3 and the metal protective sleeve 4, greatly reducing the mechanical damage to the optical fiber 1 during the manufacturing process, simplifying the process flow at the same time, and being convenient for operation.

[0033] In practical applications, the optical fiber 1 can adopt a new type of optical fiber 1. The optical fiber 1 sequentially includes a core, a polyimide coating layer and a polyether ether ketone coating layer from the inside to the outside, and has good pressure resistance, heat aging resistance, radiation aging resistance and sealing performance. After being coated with polyether ether ketone, the outer diameter of the optical fiber 1 is 0.4 mm to 1.0 mm, such as 0.4 mm, 0.7 mm or 1.0 mm, and there is no relative slip between the polyether ether ketone coating layer and the core.

[0034] In this embodiment, the metal capillary tube 2 and the metal protective sleeve 4 are made of stainless steel. Of course, other metal materials can also be selected in other embodiments. The inner diameter of the metal capillary tube 2 is 0.4 mm to 1.2 mm, such as 0.4 mm, 0.8 mm or 1.2 mm. The metal capillary tube 2 forms a clearance fit with the optical fiber 1. The outer diameter of the metal capillary tube 2 is 2.0 mm to 5.0 mm, such as 2.0 mm, 3.5 mm or 5 mm, and has a certain wall thickness to ensure the stiffness of the structure.

[0035] In this embodiment, the plastic seal 3 is made of polysulfone, polyether ether ketone, polyethersulfone or polyimide. These materials have excellent heat resistance, good mechanical properties, excellent electrical insulation properties and outstanding chemical stability. Of course, other plastics with similar properties can also be selected in other embodiments. The through hole 301 of the sealing plastic part 3 forms a clearance fit with the outer diameter of the metal capillary tube 2. According to the different numbers of the through holes 301 configured, the outer diameter of the sealing plastic part 3 and the inner diameter of the metal protective sleeve 4 can be adaptively designed, having a large adjustment range.

[0036] The wall thickness of the metal protective sleeve 4 is designed with different thicknesses according to its materials. In this embodiment, the material is selected as 06Cr19Ni 10, and the wall thickness is selected from 1 mm to 2.5 mm, such as 1 mm, 1.8 mm or 2.5 mm.

[0037] According to the size design of the optical fiber 1 and the metal capillary 2 described above, and the size matching design of other components, the miniaturization and compact design of the optical fiber penetration sealing device can be achieved.

[0038] A first thermosetting sealing material (not shown in the figure) is filled between the optical fiber 1 and the metal capillary 2. The first thermosetting sealing material is preferably epoxy resin. In other embodiments, other materials can of course be selected, such as polyurethane, silicone rubber, acrylic resin, etc. In practical applications, after the metal capillary 2, the plastic seal 3 and the metal protective sleeve 4 are integrally extruded, liquid epoxy resin is filled into the metal capillary 2, and the optical fiber 1 is inserted into the metal capillary 2. During the process of inserting the optical fiber 1 into the metal capillary 2, the liquid epoxy resin covers the surface of the optical fiber 1, and a heating device is used to cure it. It should be noted that only the optical fiber 1 in one of the metal capillaries 2 is shown in the attached figure. In practical applications, each metal capillary 2 is penetrated by an optical fiber 1.

[0039] Reference Figure 2 , sealing holes are provided at both ends of the metal capillary 2, and a sealing structure is provided in the sealing holes to further ensure the sealing performance between the optical fiber 1 and the metal capillary 2. As an option, in this embodiment, the sealing structure includes a second thermosetting sealing material 7, and the second thermosetting sealing material 7 is poured into the sealing holes. Similar to the first thermosetting sealing material, the second thermosetting sealing material 7 is preferably epoxy resin. In other embodiments, other materials can of course be selected, such as polyurethane, silicone rubber, acrylic resin, etc.

[0040] On the basis that the second thermosetting sealing material 7 is used in the sealing structure, a first metal capillary protection tube 14 is further provided. On this basis, a stepped hole is provided at the end of the metal capillary 2. After the second thermosetting sealing material 7 is poured, the first metal capillary protection tube 14 is installed in place. The outer diameter of the first metal capillary protection tube 14 forms a clearance fit with the small-diameter section of the stepped hole, and the inner diameter of the first metal capillary protection tube 14 forms a clearance fit with the optical fiber 1. Through this structure, the sealing structure is protected from the stress caused by the bending of the optical fiber 1, and the sealing structure is prevented from being damaged. Further, an organic glue 15 is provided for protection at the outer end of the first metal capillary protection tube 14 (i.e., the part where the optical fiber 1 comes out).

[0041] In addition to the above sealing method, the present invention also provides two other sealing methods for the specific sealing structure of the sealing structure (refer to Embodiment 2 and Embodiment 3), that is, a total of three methods. In practical applications, a suitable sealing method is selected according to the specific working conditions.

[0042] The present invention also provides a method for preparing a sealed optical fiber penetration device for preparing the above-mentioned sealed optical fiber penetration device, referring to Figure 4 , including the following steps:

[0043] S1. Assemble the metal capillary 2, the plastic seal 3 and the metal protection sleeve 4 together and adjust the relative positions among the three. It should be noted that since there are no strict dimensional accuracy requirements for the relative positions of the three, it is only necessary to ensure their approximate positions;

[0044] S2. Put the assembled and position-adjusted metal capillary 2, plastic seal 3 and metal protection sleeve 4 as a whole into a rolling press, and after repeated rolling to meet the target size requirements, form a tight fit among the three, which not only ensures the fixed connection among the three but also ensures the sealing performance among them;

[0045] S3. Fill each metal capillary 2 with a first thermosetting sealing material (epoxy resin is selected in this embodiment), insert the optical fiber 1 into the metal capillary 2. During the process of inserting the optical fiber 1 into the metal capillary 2, the liquid epoxy resin covers the surface of the optical fiber 1, and a heating device can be used to cure it;

[0046] S4. After the optical fiber 1 penetrates through the metal capillary 2, a sealing structure is arranged in the sealing hole of the metal capillary 2. On the basis of using a second thermosetting sealing material 7 (epoxy resin is actually selected) for sealing in this embodiment, directly pour the epoxy resin into the sealing hole and also use a heating device to cure it;

[0047] S5. Peel off the outer layer of the optical fiber 1 and connect it to a connector (not shown in the figure) to complete the preparation of the sealed optical fiber penetration device.

[0048] In practical applications, after completing the above preparation steps, the whole sealed optical fiber penetration device is installed on the sealed boundary housing 11.

[0049] Embodiment 2

[0050] Referring to Figure 5 , the difference between this embodiment and Embodiment 1 is that the sealing structure in the sealing hole of the metal capillary 2 in this embodiment is different. The sealing structure in this embodiment includes a glass solder 8, and the glass solder 8 is welded to the optical fiber 1 and the metal capillary 2. In practical applications, resistance welding technology or high-frequency induction heating welding technology is used to directly weld and package the optical fiber 1, the metal capillary 2 and the connector with the glass solder 8. Among them, the melting point of the glass solder 8 is lower than the melting point of the polyether ether ketone coating layer of the optical fiber 1. Since the melting point of the polyether ether ketone coating layer is about 340, it is optimal to select the glass solder 8 with a melting point not higher than 300 °C.

[0051] On the basis that the glass solder 8 is adopted for the sealing structure, a second metal capillary protection tube 16 is further provided. On this basis, the metal capillary tube 2 is provided with a stepped hole at the end. The outer diameter of the second metal capillary protection tube 16 forms a clearance fit with the small-diameter section of the stepped hole, and the inner diameter of the second metal capillary protection tube 16 forms a clearance fit with the optical fiber 1. Through this structure, the sealing structure is ensured to be free from the stress caused by the bending of the optical fiber 1, and the sealing structure is prevented from being damaged. Further, an organic glue 15 is also provided at the outer end of the second metal capillary protection tube 16 (i.e., the part where the optical fiber 1 comes out) for protection.

[0052] Embodiment 3

[0053] Reference Figure 6 , the difference between this embodiment and Embodiment 1 is that the sealing structure in the sealing hole of the metal capillary tube 2 in this embodiment is different. The sealing structure in this embodiment includes a compression nut 9 and a first sealing ring 10. The material of the first sealing ring 10 is preferably fluororubber. The compression nut 9 is threadedly connected to the sealing hole, and the first sealing ring 10 is pressed between the compression nut 9 and the bottom of the sealing hole. That is, an internal thread is provided in the sealing hole to connect with the compression nut 9. During the process of tightening the compression nut 9, the first sealing ring 10 is extruded and deformed to form a seal.

[0054] Embodiment 4

[0055] Reference Figure 7 , the difference between this embodiment and Embodiment 1 is that the sealing connection method between the metal protection sleeve 4 and the sealing boundary housing 11 in this embodiment is different. In this embodiment, a sealing assembly is adopted to form a seal. The sealing assembly includes a sealing flange 5 and a second sealing ring 6. The material of the second sealing ring 6 is preferably fluororubber; the metal protection sleeve 4 penetrates through the sealing boundary housing 11, the sealing flange 5 is connected to the sealing boundary housing 11 by screws, and the sealing flange 5 presses the second sealing ring 6 between the sealing boundary housing 11 and the metal protection sleeve 4; specifically, in practical applications, a counterbore is provided in the sealing boundary housing 11, the metal protection sleeve 4 is fitted with the small-diameter section of the counterbore, the sealing flange 5 is sleeved outside the metal protection sleeve 4 and is connected to the sealing boundary housing 11 by screws. During the process of connecting and tightening the sealing flange 5, it gradually extends into the large-diameter section of the counterbore, so that the second sealing ring 6 is pressed and deformed, realizing the sealing and fixing of the metal protection sleeve 4 and the sealing boundary housing 11.

[0056] Further, the sealing assembly in this embodiment further includes a pressing ring 13 and a plurality of limiting blocks 12. On this basis, a plurality of grooves are provided at intervals along the circumferential direction on the outer wall of the metal protection sleeve 4, the limiting blocks 12 are installed in the grooves, and the pressing ring 13, the sealing flange 5 and the sealing boundary housing 11 are connected and fixed by screws to limit the positions of the limiting blocks 12 and the metal protection sleeve 4.

[0057] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sealed optical fiber penetration device, comprising a metal protection sleeve, and the metal protection sleeve is hermetically connected to a sealed boundary housing, characterized in that, It further includes a plastic seal and a plurality of metal capillary tubes. The plastic seal cooperates with the inner wall of the metal protective sleeve. The plastic seal is provided with a plurality of through holes, and the metal capillary tubes are inserted into the through holes. The metal capillary tubes, the plastic seal and the metal protective sleeve are tightly fitted through rolling; an optical fiber is inserted into the metal capillary tube, and the optical fiber is hermetically connected to the metal capillary tube.

2. The sealed optical fiber penetration device according to claim 1, wherein A first thermosetting sealing material is filled between the optical fiber and the metal capillary tube.

3. The sealed optical fiber penetration device according to claim 2, characterized in that, Sealing holes are provided at both ends of the metal capillary tube, and a sealing structure is provided in the sealing holes.

4. The sealed optical fiber penetration device according to claim 3, characterized in that The sealing structure includes a second thermosetting sealing material, and the second thermosetting sealing material is poured into the sealing holes.

5. The sealed optical fiber penetration device according to claim 3, characterized in that, The sealing structure includes a glass solder, and the glass solder is welded to the optical fiber and the metal capillary tube.

6. The sealed optical fiber penetration device according to claim 3, wherein The sealing structure includes a compression nut and a first sealing ring. The compression nut is threadedly connected to the sealing hole, and the first sealing ring is pressed between the compression nut and the bottom of the sealing hole.

7. The sealed optical fiber penetration device according to any one of claims 1-5, characterized in that The metal capillary tube and the metal protective sleeve are made of stainless steel; the plastic seal is made of polysulfone, polyetheretherketone, polyethersulfone or polyimide.

8. The sealed optical fiber penetration device according to any one of claims 1-5, characterized in that, The metal protective sleeve is connected to the sealing boundary housing through a sealing assembly. The sealing assembly includes a sealing flange and a second sealing ring. The metal protective sleeve penetrates through the sealing boundary housing. The sealing flange is connected to the sealing boundary housing by screws, and the sealing flange presses the second sealing ring between the sealing boundary housing and the metal protective sleeve.

9. The sealed optical fiber penetration device according to any one of claims 1-5, characterized in that The metal protective sleeve is welded to the sealing boundary housing.

10. A method for preparing a sealed optical fiber penetration device, which is used to prepare the sealed optical fiber penetration device described in claim 3, characterized in that, It includes the following steps: S1. Assemble the metal capillary tube, the plastic seal and the metal protective sleeve together, and adjust the relative positions among the three; S2. Put the assembled and position-adjusted metal capillary tube, plastic seal and metal protective sleeve as a whole into a rolling machine, and repeatedly roll to meet the target size requirements to form a tight fit among the three; S3. Fill each metal capillary tube with a first thermosetting sealing material, and insert the optical fiber into the metal capillary tube; S4. After the optical fiber penetrates through the metal capillary tube, set a sealing structure in the sealing hole of the metal capillary tube; S5. Peel off the outer layer of the optical fiber, connect it to a connector, and complete the preparation of the sealed optical fiber penetration device.

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