Optical fiber high voltage insulating tube

Abstract

The utility model discloses a kind of optical fiber high-voltage insulation tubes, including multilayer insulation composite pipe wall structure and the pipe end sealing insulation structure allowing optical fiber to seal through;Multilayer insulation composite pipe wall structure at least includes coaxially arranged low-friction inner liner for low dielectric loss buffer, pressure-resistant insulation intermediate layer for high-temperature insulation and weather-resistant protective layer for arc protection, low-friction inner liner is coated and set on the outside of optical fiber, pressure-resistant insulation intermediate layer is coated and set on the outside of low-friction inner liner, weather-resistant protective layer is coated and set on the outside of pressure-resistant insulation intermediate layer;Pipe end sealing insulation structure is set in both ends of weather-resistant protective layer.The utility model sets multilayer insulation composite pipe wall structure and pipe end sealing insulation structure, can reliably protect optical fiber under high pressure environment, ensure the stability and security of optical fiber communication.

Description

Technical Field

[0001] This utility model relates to the field of optical fiber communication auxiliary equipment technology, and in particular to a high-voltage insulating tube for optical fibers with high voltage resistance, which is used in high-voltage environments to protect optical fibers and assist in signal transmission. Background Technology

[0002] In fiber optic communication systems, especially in scenarios closely related to high-voltage environments such as high-voltage power transmission and high-voltage testing equipment, the protection of optical fibers is crucial. Traditional fiber optic protection tubes have several shortcomings in terms of voltage withstand performance:

[0003] 1. Material Voltage Withstand Limitations: Most existing fiber optic protection tubes are made of ordinary plastic or rubber, which have limited voltage breakdown resistance. When high voltage is present in the surrounding environment, they are easily broken down, leading to the exposure of the internal optical fiber, which in turn affects the signal transmission of the fiber and may even cause damage to the fiber. For example, in high-voltage substations, some ordinary protection tubes have developed varying degrees of tracking after being subjected to electric fields for a long time, reducing the insulation performance of the protection tube.

[0004] 2. Structural Design Defects: Traditional protective tubes have a relatively simple structure and cannot effectively disperse the electric field stress generated by high voltage. In areas where high voltage is concentrated, the protective tube is more easily damaged. For example, some cylindrical protective tubes are prone to breakdown at weak points when the electric field strength is uneven, causing the protective tube to lose its protective function for the optical fiber.

[0005] 3. Insufficient Sealing Performance: In high-voltage environments, if the protective tube's sealing performance is poor, moisture, dust, and other impurities can easily enter the tube. Moisture will reduce the insulation performance of the protective tube, while dust and other impurities may form conductive channels under the influence of the electric field, triggering partial discharge and ultimately damaging the protective tube, affecting the stability of fiber optic communication. For example, in some outdoor high-voltage communication lines, rainwater entering the protective tube due to poor sealing frequently causes fiber optic short circuits.

[0006] In summary, the voltage withstand performance of existing fiber optic protection tubes cannot meet the requirements of fiber optic communication under high-voltage environments. There is an urgent need for a fiber optic protection tube with high voltage withstand performance to ensure the stable operation of optical fibers in high-voltage environments.

[0007] Therefore, based on years of experience and practice in related industries, the inventor has proposed a high-voltage insulating tube for optical fibers to overcome the shortcomings of existing technologies. Utility Model Content

[0008] The purpose of this invention is to provide a high-voltage insulating tube for optical fibers, which solves the problems of insufficient pressure resistance and long-term insulation degradation of existing optical fiber protection tubes. This invention features a multi-layer insulating composite tube wall structure and a tube end sealing insulation structure, which can reliably protect optical fibers under high-voltage conditions, play an auxiliary role in signal transmission, and ensure the stability and security of optical fiber communication.

[0009] The purpose of this utility model is achieved as follows: a high-voltage insulating tube for optical fibers includes a multi-layer insulating composite tube wall structure and a tube end sealing insulating structure that allows the optical fiber to pass through in a sealed manner; the multi-layer insulating composite tube wall structure includes at least a low-friction inner liner layer for low dielectric loss buffering, a high-temperature insulating intermediate layer, and a weather-resistant protective layer for arc protection, all coaxially arranged; the low-friction inner liner layer covers the outside of the optical fiber, the high-voltage insulating intermediate layer covers the outside of the low-friction inner liner layer, and the weather-resistant protective layer covers the outside of the high-voltage insulating intermediate layer; the tube end sealing insulating structure is disposed at both ends of the weather-resistant protective layer.

[0010] In a preferred embodiment of the present invention, a semi-conductive polyolefin shielding layer is compositely disposed on the inner side of the low-friction liner layer.

[0011] In a preferred embodiment of the present invention, the outer wall of the weather-resistant protective layer is provided with a plurality of insulating ribs arranged axially at intervals along the circumferential direction.

[0012] In a preferred embodiment of the present invention, the tube end sealing insulation structure includes a sealing end cap disposed at the end of the weather-resistant protective layer, a stepped portion disposed inside the sealing end cap, an O-ring being embedded in the stepped portion, and the pressure-resistant insulating intermediate layer and the optical fiber seal inside which covers the low-friction inner liner passing through the O-ring.

[0013] In a preferred embodiment of this utility model, the sealing end cap is threaded to the weather-resistant protective layer, and a sealant unit is filled between the abutting end faces of the sealing end cap and the weather-resistant protective layer.

[0014] In a preferred embodiment of this invention, the sealant unit is an epoxy potting compound, and the volume resistivity of the epoxy potting compound is greater than or equal to 10. 15 Ω·cm.

[0015] In a preferred embodiment of this utility model, the O-ring is an O-ring silicone rubber seal, and the Shore hardness of the O-ring silicone rubber seal is 60-70HA.

[0016] In a preferred embodiment of this utility model, the low-friction inner liner is a modified polytetrafluoroethylene layer.

[0017] In a preferred embodiment of this utility model, the pressure-resistant insulating intermediate layer is a ceramicized silicone rubber layer.

[0018] In a preferred embodiment of this utility model, the weather-resistant protective layer is an arc-resistant epoxy resin layer.

[0019] As described above, the optical fiber high-voltage insulating tube of this utility model has the following beneficial effects:

[0020] 1. High withstand voltage performance: Through structural optimization and material innovation, the innovative design of a multi-layer insulating composite tube wall structure improves the withstand voltage breakdown capability of the optical fiber high voltage insulating tube by more than 85% compared with the traditional protective tube, and can withstand a high voltage of 100KV, effectively ensuring the safety of optical fiber in high voltage environment.

[0021] 2. Long service life: The weather-resistant outer protective layer and the good end sealing insulation structure enable the insulating tube to adapt to various harsh environmental conditions, reduce the impact of external factors on its performance, extend the service life of the insulating tube, and reduce maintenance costs.

[0022] 3. Stable signal transmission: The reliable protection provided by the multi-layered insulated composite tube wall structure ensures that the optical fiber will not be damaged under high pressure, guaranteeing the stable transmission of optical fiber communication signals and improving the reliability of the communication system. Attached Figure Description

[0023] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the present invention. Wherein:

[0024] Figure 1 This is a schematic diagram of the high-voltage insulating tube for optical fibers according to this utility model.

[0025] In the picture:

[0026] 100. High-voltage insulating tube for optical fibers;

[0027] 1. Multi-layer insulated composite pipe wall structure;

[0028] 11. Low-friction inner lining layer; 12. Pressure-resistant insulating intermediate layer; 13. Weather-resistant protective layer;

[0029] 2. Pipe end sealing and insulation structure; 21. Sealing end cap; 211. Stepped portion; 22. O-ring seal;

[0030] 3. Optical fiber. Detailed Implementation

[0031] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described with reference to the accompanying drawings.

[0032] The specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the present invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on this invention, and these should all be considered within the scope of this invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "linked" should be interpreted broadly; for example, they can refer to mechanical or electrical connections, or internal connections between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] like Figure 1 As shown, this utility model provides a high-voltage insulating tube 100 for optical fibers, including a multi-layer insulating composite tube wall structure 1 and a tube end sealing insulating structure 2 that allows the optical fiber to pass through in a sealed manner; the multi-layer insulating composite tube wall structure 1 includes at least a low-friction inner liner 11 for low dielectric loss buffering, a high-temperature insulating intermediate layer 12, and a weather-resistant protective layer 13 for arc protection, all arranged coaxially; the low-friction inner liner 11 is disposed on the outside of the optical fiber, the high-pressure insulating intermediate layer 12 is disposed on the outside of the low-friction inner liner 11, and the weather-resistant protective layer 13 is disposed on the outside of the high-pressure insulating intermediate layer 12; the tube end sealing insulating structure 2 is disposed at both ends of the weather-resistant protective layer 13.

[0035] In the multi-layer insulating composite pipe wall structure 1 of this utility model, the three layers of low-friction inner lining layer 11, pressure-resistant insulating intermediate layer 12, and weather-resistant protective layer 13 are formed by co-extrusion-curing integrated process to form a gradient system of "low dielectric loss buffer - high temperature insulation - arc protection".

[0036] The working principle of this invention is as follows: When high voltage is applied to the high-voltage insulating tube 100 of the optical fiber, the multi-layer insulating composite tube wall structure 1 (multi-layer nested structure) works synergistically. The inner low-friction liner layer 11 protects the optical fiber from frictional damage; the middle pressure-resistant insulating intermediate layer 12, with its high strength and good insulation performance, withstands and disperses electric field stress, preventing high voltage from breaking down the insulating tube; the outer weather-resistant protective layer 13 resists damage to the internal structure from external environmental factors; and the tube end sealing insulation structure 2 at both ends ensures the dryness and cleanliness of the inside of the insulating tube, maintaining a good insulation environment, thereby ensuring that the insulating tube can operate stably under high voltage conditions and protecting the optical fiber for normal signal transmission.

[0037] This utility model has the following beneficial effects:

[0038] 1. High withstand voltage performance: Through structural optimization and material innovation, the innovative design of a multi-layer insulating composite tube wall structure improves the withstand voltage breakdown capability of the optical fiber high voltage insulating tube by more than 85% compared with the traditional protective tube, and can withstand a high voltage of 100KV, effectively ensuring the safety of optical fiber in high voltage environment.

[0039] 2. Long service life: The weather-resistant outer protective layer and the good end sealing insulation structure enable the insulating tube to adapt to various harsh environmental conditions, reduce the impact of external factors on its performance, extend the service life of the insulating tube, and reduce maintenance costs.

[0040] 3. Stable signal transmission: The reliable protection provided by the multi-layered insulated composite tube wall structure ensures that the optical fiber will not be damaged under high pressure, guaranteeing the stable transmission of optical fiber communication signals and improving the reliability of the communication system.

[0041] Furthermore, a semi-conductive polyolefin shielding layer is compositely disposed on the inner side of the low-friction inner liner 11.

[0042] Specifically, a 0.2mm thick semi-conductive polyolefin shielding layer is laminated to the inner side of the low-friction inner liner 11, which achieves a uniform electric field. This uniform electric field distribution prevents induced voltage from forming in the optical fiber due to uneven electric field distribution, thus reducing the bit error rate of the optical fiber signal transmission to 10. -9 The following addresses the core issues in resolving strong electric field interference signals.

[0043] The innovative design of the multi-layer insulating composite pipe wall structure 1 of this utility model breaks through the limitations of traditional single insulation. In the multi-layer insulating composite pipe wall structure 1 of this utility model, the low-friction inner lining layer 11, the pressure-resistant insulating intermediate layer 12, and the weather-resistant protective layer 13 are formed by co-extrusion-curing integrated process, forming a gradient system of "low dielectric loss buffer - high temperature insulation - arc protection"; a semi-conductive polyolefin shielding layer is composited on the inner side of the low-friction inner lining layer 11, which uniformly distributes the electric field and solves the core problem of strong electric field interference signals.

[0044] Furthermore, the outer wall of the weather-resistant protective layer 13 is provided with multiple insulating ribs arranged axially at intervals along the circumferential direction.

[0045] Specifically, 3-5 axial insulating ribs (semi-circular cross-section, 1.5mm diameter) are evenly arranged on the outer circumference of the tube wall (outer wall of the weather-resistant protective layer 13). These ribs are made of tracking-resistant resin and are integrally molded with the weather-resistant protective layer 13 (outer layer). The insulating ribs can increase the surface creepage distance of the fiber optic high-voltage insulating tube 100 (from the traditional 15mm to 25-30mm), suppress surface discharge, and prevent dust and condensation from forming a continuous conductive channel on the tube wall surface, so that the tracking resistance of the insulating tube reaches the V1 level in GB / T 4207.

[0046] Furthermore, the pipe end sealing insulation structure 2 includes a sealing end cap 21 disposed at the end of the weather-resistant protective layer 13, a step portion 211 is provided inside the sealing end cap 21, an O-ring seal 22 is embedded in the step portion 211, and the low-friction inner liner 11 and the optical fiber seal inside it pass through the O-ring seal 22.

[0047] Furthermore, the sealing end cap 21 is connected to the weather-resistant protective layer 13 by threads, and the end faces of the sealing end cap 21 and the weather-resistant protective layer 13 that abut against each other are filled with sealant units.

[0048] Furthermore, the sealant unit is an epoxy potting compound with a volume resistivity ≥10. 15 Ω·cm.

[0049] Furthermore, the O-ring 22 is an O-ring silicone rubber seal with a Shore hardness of 60-70 HA.

[0050] Specifically, the fiber optic high-voltage insulating tube 100 adopts a "stepped sealing + insulation potting" design within a 10mm range at both ends. An O-ring silicone rubber seal (Shore hardness 60-70HA) is embedded in the step portion 211 inside the sealing end cap 21, and the tube end is filled with epoxy potting compound (volume resistivity ≥10). 15 (Ω·cm), to prevent moisture intrusion due to poor sealing at the pipe ends, avoid degradation of the insulation performance inside the pipe, and ensure that the withstand voltage strength at the pipe ends is consistent with that of the pipe body (≥25kV / mm).

[0051] The axial insulating ribs and the pipe end sealing insulation structure 2 of this utility model achieve optimized resistance to electric field interference and surface anti-fouling, effectively solving the problem of insulation performance attenuation.

[0052] Furthermore, the low-friction inner liner 11 is a modified polytetrafluoroethylene (PTFE) layer. Preferably, the thickness of this layer is 2 mm.

[0053] Furthermore, the voltage-resistant insulating intermediate layer 12 is a ceramicized silicone rubber layer. Preferably, the thickness of this layer is 2 mm. As an intermediate layer, the ceramicized silicone rubber layer can maintain a voltage withstand strength of over 25 kV / mm at a high temperature of 180°C, which is 4-5 times higher than that of traditional polyethylene materials, and can withstand instantaneous impulse voltages below 500 kV.

[0054] To modify the dielectric loss of the intermediate layer (voltage-resistant insulating intermediate layer 12), 3%-5% of nano-alumina (particle size 50-80nm) is added to the ceramicized silicone rubber layer, so that the dielectric loss tangent (tanδ) of the material is reduced to below 0.002 at a frequency of 50Hz, thereby reducing the heat accumulation caused by dielectric loss in the electric field and avoiding local overheating of the tube wall leading to insulation failure.

[0055] Furthermore, the weather-resistant protective layer is an arc-resistant epoxy resin layer. Preferably, the thickness of this layer is 1.5 mm.

[0056] To optimize the outer anti-aging properties, 2%-3% of hindered phenolic antioxidant (1076) and 1%-2% of ultraviolet absorber (UV-531) are added to the arc-resistant epoxy resin layer. This ensures that the voltage resistance attenuation rate of the insulating tube is less than 5% / year under strong ultraviolet and high / low temperature (-40℃~120℃) outdoor environments, guaranteeing a long service life and solving the problem of insulation performance degradation of traditional insulating tubes over long-term use.

[0057] In summary, the material dielectric loss and anti-aging properties of each layer of the multi-layer insulating composite tube wall structure 1 of this utility model are synergistically optimized, thereby achieving long-term stable insulation performance of the optical fiber high-voltage insulating tube 100.

[0058] Example 1:

[0059] In a fiber optic communication upgrade project at a 33kV high-voltage substation, the fiber optic high-voltage insulating tube 100 of this invention replaced the original ordinary protective tube. The original protective tube frequently caused fiber optic faults due to insufficient withstand voltage, affecting the substation's monitoring and communication systems. After replacement with this invention, operational monitoring showed no further faults caused by withstand voltage issues. Subsequent equipment maintenance revealed that the insulating tube was structurally intact, the internal optical fibers were undamaged, and its sealing performance was excellent, effectively verifying the superior long-term withstand voltage performance and operational reliability of this fiber optic high-voltage insulating tube.

[0060] Example 2:

[0061] The fiber optic high-voltage insulating tube 100 provided by this utility model is suitable for high-speed pantograph-catenary integrated testing devices. This device is installed on the roof of a vehicle and is used for high and low voltage signal isolation transmission: it transmits the signal collected from the 27.5kV high-voltage environment on the pantograph body to the roof of the vehicle, and then introduces the optical signal into the vehicle through fiber optic cables.

[0062] The fiber optic high-voltage insulated tube 100 is designed with a 1.2-meter creepage distance and is equipped with fittings at both ends for easy connection of the pantograph to the roof-mounted base. Two special aviation fiber optic connectors are installed at each end of the high-voltage insulated tube, and the gap between the cable tail sheath and the tightly packed fiber at the connector end face is sealed and waterproofed. These connectors are used to connect the high-voltage side equipment to the roof-mounted fiber optic cable.

[0063] Operational monitoring showed that the fiber optic high-voltage insulating tube 100 did not experience any failures due to voltage withstand issues. Upon replacement after a period of operation, its structure was found to be intact, the internal optical fibers undamaged, and its sealing performance excellent, effectively verifying the superior high-voltage withstand performance and long-term reliability of the fiber optic high-voltage insulating tube 100 of this invention.

[0064] The above description is merely an illustrative embodiment of this utility model and is not intended to limit the scope of this utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of this utility model should fall within the protection scope of this utility model.

Claims

1. A high-voltage insulating tube for optical fibers, characterized in that, The device includes a multi-layered insulated composite tube wall structure and a tube end sealing insulation structure that allows the optical fiber to pass through. The multi-layered insulated composite tube wall structure includes at least a low-friction inner liner for low dielectric loss buffering, a high-temperature insulating intermediate layer, and a weather-resistant protective layer for arc protection, all coaxially arranged. The low-friction inner liner covers the outer side of the optical fiber, the high-voltage insulating intermediate layer covers the outer side of the low-friction inner liner, and the weather-resistant protective layer covers the outer side of the high-voltage insulating intermediate layer. The tube end sealing insulation structure is located at both ends of the weather-resistant protective layer.

2. The optical fiber high-voltage insulating tube as described in claim 1, characterized in that, A semi-conductive polyolefin shielding layer is compositely disposed on the inner side of the low-friction liner.

3. The optical fiber high-voltage insulating tube as described in claim 1, characterized in that, The outer wall of the weather-resistant protective layer is provided with multiple insulating ribs arranged axially at intervals along the circumferential direction.

4. The optical fiber high-voltage insulating tube as described in claim 1, characterized in that, The tube end sealing insulation structure includes a sealing end cap disposed at the end of the weather-resistant protective layer, a stepped portion provided inside the sealing end cap, an O-ring embedded in the stepped portion, and the pressure-resistant insulating intermediate layer and the optical fiber seal inside which covers the low-friction inner liner passing through the O-ring.

5. The optical fiber high-voltage insulating tube as described in claim 4, characterized in that, The sealing end cap is threaded to the weather-resistant protective layer, and the end faces of the sealing end cap and the weather-resistant protective layer that abut against each other are filled with sealant units.

6. The high-voltage insulating tube for optical fibers as described in claim 5, characterized in that, The sealant unit is an epoxy potting compound, and the volume resistivity of the epoxy potting compound is greater than or equal to 10. 15 Ω·cm.

7. The optical fiber high-voltage insulating tube as described in claim 4, characterized in that, The O-ring is a silicone rubber O-ring with a Shore hardness of 60-70 HA.

8. The high-voltage insulating tube for optical fibers as described in claim 1, characterized in that, The low-friction liner is a modified polytetrafluoroethylene layer.

9. The optical fiber high-voltage insulating tube as described in claim 1, characterized in that, The pressure-resistant insulating intermediate layer is a ceramicized silicone rubber layer.

10. The optical fiber high-voltage insulating tube as described in claim 1, characterized in that, The weather-resistant protective layer is an arc-resistant epoxy resin layer.

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