Optical fiber sensor interface for GIS and preparation method thereof

Abstract

The invention relates to an optical fiber sensor interface for a GIS and a preparation method thereof, the optical fiber sensor interface for the GIS is used for connecting GIS equipment and an optical fiber sensor, and the interface comprises a central layer and at least one additional layer arranged around the central layer; the central layer is provided with an optical fiber sensor mounting port; when the number of the additional layer is one, the central layer and the additional layer have different expansion rates; when the number of the additional layers is multiple, the central layer and the additional layers have different expansion rates. Through the design of the multi-layer different expansion rate structure, the scheme can effectively deal with the problem of thermal expansion and cold contraction generated when the temperature of the GIS interface changes. The materials of all layers change according to the preset expansion rate, the buffering effect is generated between the materials, concentration and release of internal stress are reduced, and therefore the cracking phenomenon is avoided.

Description

Technical Field

[0001] The present invention belongs to the field of electrical equipment detection, and particularly relates to an optical fiber sensor interface for GIS and a preparation method thereof. Background Art

[0002] GIS (Gas Insulated Switchgear) is a high-voltage combined electrical apparatus composed of a circuit breaker, a disconnector, an earthing switch, an instrument transformer, a lightning arrester, a busbar, a connection structure, an outgoing terminal, etc.

[0003] An optical fiber grating is a diffraction grating formed by axially periodically modulating the refractive index of an optical fiber core through a specific method. As a passive filtering device, it has the advantages of small volume, low fusion loss, full compatibility with optical fibers, and the ability to be embedded in intelligent materials. A single-mode optical fiber is an optical fiber that can only transmit one mode. Its core diameter is small (usually about 9 μm), so the transmission loss is low, the transmission distance is far, and the anti-electromagnetic interference ability is strong. A fluorescent optical fiber is an optical fiber that can emit fluorescent signals. Its working principle is to incorporate fluorescent substances (such as rare earth elements, etc.) into the optical fiber. When the optical fiber is excited by light of a specific wavelength, it will emit fluorescent signals. The multi-physical quantity spectral discrimination technology is a technology that combines the measurement of multiple physical quantities with spectral analysis. In the power industry, this technology can analyze and process the spectral signals collected by sensors such as optical fiber gratings, single-mode optical fibers, and fluorescent optical fibers to realize real-time monitoring and discrimination of multiple physical quantities in the power system. This helps to improve the monitoring accuracy and intelligent level of the power system and provides a strong guarantee for the safe and stable operation of the power system.

[0004] The application of the multi-physical quantity spectral discrimination technology of optical fiber gratings, single-mode optical fibers, and fluorescent optical fibers in the power industry, especially in combination with GIS equipment, has significant technical advantages and application prospects. By combining with GIS equipment, comprehensive monitoring and intelligent management of the power system can be realized, providing a strong guarantee for the safe and stable operation of the power system. When integrating sensors such as optical fiber gratings, single-mode optical fibers, and fluorescent optical fibers while realizing the multi-physical quantity spectral discrimination function with GIS equipment, the insulation and airtightness requirements of GIS equipment need to be taken into account.

[0005] At present, the sealing methods include potting sealing, vacuum rubber gaskets, threaded compression rings, positioning snap rings, etc. At the interface between the optical fiber and the GIS system, a special potting sealing structure is usually adopted. This structure fills the gap between the optical fiber and the interface tightly by pouring a specific sealing glue, so as to achieve the sealing effect. In some cases, vacuum rubber gaskets are used to seal between the optical fiber and the interface. This kind of gasket has good elasticity and sealing performance, and can effectively prevent the leakage of gas or liquid. In order to ensure the stability and sealing performance of the optical fiber at the interface, fixing parts such as threaded compression rings and positioning snap rings are usually used. These fixing parts fix the optical fiber firmly at the interface through threaded connection or clamping, and at the same time achieve the sealing effect.

[0006] However, the currently commonly adopted solutions lack the scalability for technical solutions such as optical fiber bundles. At the same time, since no additional design structure is added, ordinary sealing glue is used to fill the gap. During long-term use, there may be defects such as cracks, resulting in sealing failure and mechanical property failure. Moreover, traditional GIS interfaces often adopt a single material or a multi-layer structure design with a uniform expansion rate, and it is difficult to effectively cope with the thermal expansion and contraction problems caused by temperature changes in complex environments. Therefore, there is an urgent need to develop an interface integration method that can safely integrate sensors such as fiber Bragg gratings, single-mode optical fibers, and fluorescent optical fibers with GIS devices while realizing the multi-physical quantity spectral discrimination function, taking into account the insulation and airtightness requirements of GIS devices. Summary of the Invention

[0007] The purpose of the present invention is to solve the problem of sealing failure caused by thermal expansion and contraction of existing GIS interfaces in complex environments.

[0008] The purpose of the present invention is achieved by adopting the following technical solutions:

[0009] An optical fiber sensor interface for GIS, the interface is used for connecting a GIS device and an optical fiber sensor, and the interface includes a central layer and at least one additional layer arranged around the central layer;

[0010] The central layer is provided with an optical fiber sensor installation port;

[0011] The central layer and each of the additional layers have different expansion rates.

[0012] Preferably, when the additional layer is multiple layers, the number of layers of the additional layer is n, including a first additional layer adjacent to the central layer, a second additional layer adjacent to the first additional layer,..., and an nth additional layer adjacent to the (n - 1)th additional layer;

[0013] Among them, the expansion rate of the central layer is higher than that of the first additional layer, and the expansion rates of the central layer and the additional layers, as well as different additional layers, are arranged alternately in a high-low order layer by layer.

[0014] Preferably, in the alternately arranged central layer and additional layers, for any two adjacent layers, the expansion rate of the layer with a lower expansion rate is a, and the expansion rate of the layer with a higher expansion rate is b, where 0.1% ≤ a ≤ 0.5% and 0.5% ≤ b ≤ 2%.

[0015] Preferably, the central layer and the additional layers are made of epoxy resin-based materials with different expansion rates.

[0016] Based on the same inventive concept, the present invention also provides an interface treatment method for interlayer bonding treatment between the central layer and additional layers of the GIS fiber optic sensor interface, as well as between additional layers, including using one or more of the methods such as adhesives, chemical treatment agents, and mechanical structure locking for interlayer bonding treatment between the central layer and additional layers, and between additional layers.

[0017] Preferably, the adhesive is an epoxy resin-based adhesive.

[0018] Preferably, the mechanical structure locking specifically utilizes mechanical principles to apply a clamping force between layers by inserting mechanical jigs into each layer.

[0019] Based on the same inventive concept, the present invention also provides a curing process for curing the GIS fiber optic sensor interface, which is characterized by including the following steps:

[0020] When there are multiple additional layers:

[0021] Inject the central layer epoxy resin raw material into the central layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface;

[0022] Inject the first additional layer epoxy resin raw material into the first additional layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface;

[0023] Repeat the above steps until the formation and curing treatment of the nth additional layer are completed;

[0024] Put the obtained multi-layer structure into a high-temperature oven for overall curing treatment to complete the curing.

[0025] Preferably, when there are multiple additional layers:

[0026] Inject the central layer epoxy resin raw material into the central layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface;

[0027] Inject the first additional layer epoxy resin raw material into the first additional layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface;

[0028] Repeat the above steps until the forming and curing of the nth additional layer are completed;

[0029] Put the obtained multi-layer structure into a high-temperature oven for overall curing to complete the curing.

[0030] Based on the same inventive concept, the present invention also provides a curing process, in which partitions are arranged between layers, epoxy resin raw materials are injected respectively, after semi-curing, the partitions are removed, interface treatment is carried out, and finally overall curing treatment is carried out;

[0031] The requirement for the degree of semi-curing is that the liquid mixed raw materials between layers do not flow into each other, and after removing the partitions and carrying out interface treatment, there are no air gaps between layers.

[0032] Based on the same inventive concept, the present invention also provides a preparation method of the fiber optic sensor interface for GIS as described above, including the following steps:

[0033] According to the design requirements, prepare epoxy resin raw materials with different expansion rates; a low expansion rate formula is used for the inner layer, a suitable expansion rate formula is selected for the outer layer according to the external environmental conditions, and two different expansion rate formulas are blended according to the alternating pattern of "big small big small" for the middle layer. The raw materials are fully mixed and homogenized to ensure the consistency and stability of the formula.

[0034] According to the size and shape requirements of the fiber optic sensor interface for GIS, design and manufacture a special injection or compression mold; the mold needs to have precise size and shape control capabilities, as well as good heat conduction performance.

[0035] Inject the epoxy resin raw materials with different expansion rates into the special mold, and carry out curing and interface treatment;

[0036] After the overall curing is completed, take out the interface, carry out grinding and polishing, process fiber optic sensor installation holes and sealing grooves on the central layer, and fill with special sealant to obtain the fiber optic sensor interface for GIS.

[0037] Preferably, the preparation method further includes, after obtaining the fiber optic sensor interface for GIS, passing the fiber optic sensor through the fiber optic sensor installation port and then carrying out secondary curing.

[0038] Preferably, a flexible sleeve is installed on the optical fiber, and after passing through the fiber optic sensor installation port, secondary curing is carried out.

[0039] Installing a flexible sleeve on the surface of the optical fiber can avoid the influence of external force damage and temperature change on the fiber optic sensor.

[0040] Compared with the prior art, the beneficial effects of the present invention are:

[0041] The optical fiber sensor interface for GIS described in the present invention is used for connecting a GIS device and an optical fiber sensor. The interface includes a central layer and at least one additional layer arranged around the central layer; the central layer is provided with an optical fiber sensor mounting opening; the central layer and the additional layer, as well as different additional layers, have different expansion rates. Through the design of a multi-layer structure with different expansion rates, this solution can effectively address the thermal expansion and contraction problems generated by the GIS interface during temperature changes. The materials of each layer change according to a predetermined expansion rate, generating a buffering effect on each other, reducing the concentration and release of internal stress, and thus avoiding the occurrence of cracking phenomena.

[0042] The present invention also provides an interface treatment method. In the multi-layer structure design, the interfacial bonding force is a key factor to ensure the overall strength and stability. This solution adopts a refined interface treatment technology, and significantly enhances the interfacial bonding force by methods such as selecting appropriate adhesives, chemical treatment agents, or mechanical locking structures. This technology not only improves the reliability of the product, but also reduces the failure rate caused by interfacial separation and cracking.

[0043] The present invention also provides a curing process. Traditional curing processes often have difficulty ensuring that the materials of each layer in the multi-layer structure are fully cross-linked and form a dense overall structure. This solution realizes the uniform cross-linking and densification of the materials of each layer by optimizing the overall curing process, including precisely controlling parameters such as curing temperature, time, and pressure. This optimization not only improves the overall strength and heat resistance of the interface, but also eliminates internal stress and residual stress, further improving the stability and durability of the product.

[0044] Enhancing sealing and protection performance: In response to the special requirements of optical fiber sensors, this solution designs a dedicated sealing and protection structure. The optical fiber sensors in the GIS system have extremely high requirements for sealing and protection performance. This solution innovatively designs a sealing and protection structure for optical fiber sensors, including a sealing groove provided at the edge of the round hole, a special sealing adhesive filled, and flexible sleeves and other components. The use of the sealing groove and the special sealing adhesive ensures the effective sealing of the optical fiber sensor; the flexible sleeve provides additional protection to prevent the optical fiber sensor from being damaged by external forces and affected by temperature changes. This design not only ensures the effective sealing of the optical fiber sensor and protection from external force damage, but also improves the operation safety and reliability of the GIS system after the original sensor is installed.

[0045] The multi-layer structure design with different expansion rates of this solution has high flexibility and scalability. By adjusting the expansion rates and the number of layers of each layer, it can adapt to different usage environments and performance requirements. At the same time, the interface treatment technology and the overall curing process also have a certain degree of generality and can be applied to other similar multi-layer structure designs. This flexibility and scalability make this solution have a broader application prospect and market potential.

[0046] Improve product reliability and service life: By comprehensively considering aspects such as thermal expansion and contraction, strength, sealing performance, and protection performance, this solution significantly improves the reliability and service life of the GIS interface. This is of great significance for ensuring the safe and stable operation of the GIS system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a cross-sectional schematic diagram of the optical fiber sensor interface for GIS of the present invention;

[0048] Among them: 1. Central layer; 101. Optical fiber sensor installation port; 2. First additional layer; 3. Second additional layer; 4. Third additional layer. DETAILED DESCRIPTION OF THE INVENTION

[0049] The following further describes the technical solution in conjunction with the drawings and specific embodiments to help understand the content of the present invention.

[0050] The required equipment includes:

[0051] Material mixing equipment

[0052] Mixing machine: It is used to fully mix the epoxy resin raw materials and their additives to ensure the consistency and stability of the formula. The mixing machine should be equipped with an accurate metering system and efficient stirring ability.

[0053] Mold design and manufacturing equipment

[0054] Numerical control machine tool (CNC): It is used to precisely machine each component of the mold, including structures such as annular cavities and interface treatment grooves. The CNC machine tool can ensure the dimensional accuracy and shape accuracy of the mold.

[0055] Electrical discharge machining machine (EDM): For some complex shapes or microstructures that are difficult to achieve by traditional mechanical processing methods, the electrical discharge machining machine can be used for fine machining.

[0056] Injection / molding equipment

[0057] Injection molding machine: If the injection molding process is adopted, an injection molding machine is required to inject the molten epoxy resin raw materials into the mold. The injection molding machine should be equipped with appropriate injection pressure, injection speed, and temperature control systems.

[0058] Molding press: If the molding process is adopted, a molding press is required to press and form the epoxy resin raw materials. The molding press should be equipped with sufficient pressure, temperature, and time control functions.

[0059] Curing equipment

[0060] High-temperature oven: It is used for overall curing treatment of the multi-layer structure. The high-temperature oven should be equipped with an accurate temperature control system and uniform heat field distribution to ensure that each layer of material is fully crosslinked.

[0061] Post-processing equipment

[0062] Grinder: Used to grind the cured interface to eliminate surface defects and improve surface quality.

[0063] Polisher: Further polish the interface to obtain a smoother and brighter surface effect.

[0064] Drilling machine: If circular holes or other hole structures need to be machined on the interface, a drilling machine is required for precise machining.

[0065] Sealant coater: For sealant grooves that need to be filled with sealant, a sealant coater can be used for automated coating operations to improve production efficiency and coating quality.

[0066] Adhesive preparation:

[0067] The formula of epoxy resin adhesive can be adjusted according to specific application requirements, but usually includes epoxy resin, hardener, filler, and possibly solvents and curing accelerators. The following is an overview of a basic epoxy resin adhesive formula and its production process:

[0068] Formulation components

[0069] Epoxy resin: This is the main component of the adhesive. Different models and brands of epoxy resins have different properties and characteristics. Common epoxy resin models include E-51, E-44, etc. As the main component, its proportion usually accounts for a relatively large share of the total volume, generally between 60% - 90%, depending on the required final properties. For example, for applications requiring higher strength, a higher proportion of epoxy resin may be selected.

[0070] Hardener: Used to chemically react with epoxy resin to make it cure. The selection of hardener should match the epoxy resin. Common hardeners include amines, acid anhydrides, etc. The dosage of hardener usually has a certain ratio relationship with epoxy resin, such as the common ratio of 100:10 (epoxy resin: hardener). The dosage of hardener is closely related to epoxy resin. The common ratio range varies from 5% to 30% of the epoxy resin amount, but the most commonly used is 10% - 20%. As mentioned earlier, 100:10 (epoxy resin: hardener) is a common starting point, but the specific ratio needs to be adjusted according to the types and performance requirements of the selected epoxy resin and hardener.

[0071] Filler: Used to enhance the strength, hardness or change other properties of epoxy resin glue. Common fillers include silica powder, metal powder, alumina, etc. The addition amount of the filler should be adjusted according to specific requirements. The addition amount of the filler varies greatly, from 0% (no filler) to 40% or even higher. It specifically depends on the required physical properties (such as strength, hardness, wear resistance), cost considerations and the final application environment. For example, in applications requiring high thermal conductivity, a high proportion of metal powder or graphite may be added.

[0072] Solvent: Used to adjust the viscosity of epoxy resin glue to make it easier to coat and flow. Commonly used solvents include alcohols, ketones, etc. The addition of the solvent is mainly used to adjust the viscosity, and its proportion is generally low, usually between 0% - 10%, to avoid excessive dilution affecting the properties after curing.

[0073] Curing accelerator: In some cases, to accelerate the curing process, a curing accelerator can be added. The choice of the curing accelerator should be determined according to the types of epoxy resin and hardener. The dosage of the curing accelerator is very small, generally between 0.1% - 5% of the total mass of epoxy resin and hardener, specifically depending on the required curing speed and temperature conditions.

[0074] Manufacturing process

[0075] Prepare a container: Select a clean container for mixing epoxy resin and hardener.

[0076] Mix epoxy resin and hardener: According to the ratio requirements, pour epoxy resin and hardener into the container, and use a stirring rod or stirrer to mix them evenly.

[0077] Add filler: The mixing time is generally between 2 and 5 minutes, specifically depending on the efficiency of the mixing equipment and the viscosity of the mixture. Add an appropriate amount of filler to the mixed epoxy resin and hardener, and stir evenly again. When mixing epoxy resin and hardener, it is recommended to use an electric stirrer to ensure uniform mixing and avoid local uncured areas. Pour the prepared epoxy resin, hardener and other additives into a clean container according to the formula ratio. Use a stirring rod or electric stirrer to stir thoroughly until all components are evenly mixed and there are no bubbles. During the stirring process, pay attention to controlling the stirring speed and stirring time to avoid generating too much heat or introducing air.

[0078] Adjust viscosity: According to actual needs, an appropriate amount of solvent can be added to adjust the viscosity of epoxy resin glue. The temperature during the mixing and curing processes has a significant impact on the reaction rate and final properties, and should be appropriately controlled according to the data sheet of the selected materials.

[0079] Curing: The length of the curing time depends on factors such as the ingredient ratio in the formulation, ambient temperature, and humidity. Generally, the curing time can range from a few minutes to several hours, or even longer (such as 24 - 48 hours). Place the mixed epoxy resin adhesive at an appropriate temperature for the curing reaction. During the curing process, the environment should be kept stable to avoid temperature fluctuations or excessive humidity. After curing is completed, the epoxy resin adhesive will form a solid colloid with excellent physical and chemical properties.

[0080] Storage and Use: Pour the mixed epoxy resin adhesive into a sealed container and store it in a cool and dry place. Before use, stir it evenly again and apply it to the surface of the object to be bonded, and wait for it to cure.

[0081] Preparation of Materials with Different Coefficient of Thermal Expansion

[0082] Materials with different coefficient of thermal expansion are selected to be made of epoxy resin. The preparation of epoxy resin generally includes the following steps:

[0083] Raw Material Preparation: Select appropriate compounds containing active hydrogen atoms such as polyphenols, polyols, polyacids, polyamines, etc. as raw materials, and at the same time prepare compounds containing epoxy groups such as epichlorohydrin.

[0084] Polycondensation Reaction: Under the action of a catalyst (such as NaOH), the raw materials are subjected to a polycondensation reaction. This step is a key process for forming the molecular structure of epoxy resin. For bisphenol A type epoxy resin, common production methods include the one-step method and the two-step method. The one-step method is to carry out polycondensation of bisphenol A and epichlorohydrin in a certain molar ratio under the action of a catalyst, which is suitable for synthesizing low- and medium-molecular-weight resins. The two-step method is to first synthesize a low-molecular-weight prepolymer and then further polymerize it to obtain a high-molecular-weight resin.

[0085] Post-treatment: After the polycondensation reaction is completed, the product needs to be post-treated, including washing, extraction, drying, etc., to remove impurities and improve the purity and quality of the product.

[0086] Curing Agent Addition: According to needs, add curing agents such as amines and acid anhydrides to the epoxy resin to promote the curing reaction of the epoxy resin.

[0087] The coefficient of thermal expansion of epoxy resin is not directly related to density, but is related to factors such as its molecular structure, crosslinking density, filler type and content, etc. Specifically, it includes:

[0088] Molecular Structure: The molecular structure of epoxy resin determines its thermal expansion performance. The flexibility of the molecular chain, the density of crosslinking points, etc. will all affect the coefficient of thermal expansion.

[0089] Crosslink density: The higher the crosslink density, the better the thermal stability of the epoxy resin, and the coefficient of thermal expansion and contraction may be relatively small. However, too high a crosslink density may also cause the material to become brittle.

[0090] Type and content of fillers: The addition of fillers can change the thermal expansion properties of the epoxy resin. Different types of fillers have different effects on the coefficient of thermal expansion and contraction; at the same time, the content of the fillers will also affect the change range of the coefficient of thermal expansion and contraction.

[0091] Process conditions: During the curing process of the epoxy resin, process conditions (such as curing temperature, curing time, etc.) will also affect its coefficient of thermal expansion and contraction. Therefore, these factors need to be comprehensively considered in the design and production processes to control the coefficient of thermal expansion and contraction.

[0092] Crosslink density refers to the number of crosslink bonds in a crosslinked polymer, generally expressed by the size of the molecular weight of the network chain. The greater the crosslink density, that is, the more crosslink bonds per unit volume, the greater the degree of crosslinking.

[0093] Crosslink influencing factors include:

[0094] Molecular weight of the resin itself: The higher the molecular weight of the epoxy resin, the correspondingly greater the crosslink density. High molecular weight resin molecules contain more crosslink monomers and can form more crosslink bonds during curing.

[0095] Type and dosage of crosslinking agent: The crosslinking agent is an important part of the curing reaction, and its type and dosage will directly affect the crosslink density of the epoxy resin. For example, the greater the dosage of the hardener, the higher the crosslink density.

[0096] Curing temperature: Curing temperature is another important factor affecting the crosslink density of the epoxy resin. Generally speaking, the higher the curing temperature, the faster the crosslinking reaction rate, the formation of crosslink bonds will be correspondingly strengthened, and thus the crosslink density will be increased.

[0097] Resin structure: Resins with high solid content and multiple epoxy groups also have higher crosslink densities. This is because more epoxy groups mean that more crosslink bonds can be formed.

[0098] In this patent, the physical properties affected by crosslinking are: Crosslink density will affect the physical properties of epoxy resin such as hardness, wear resistance, and solvent resistance. Generally speaking, the higher the crosslink density, the better these physical properties. Crosslinked bodies with higher densities usually have higher strength, hardness, and wear resistance, but too high a degree of crosslinking may also cause a decrease in impact strength.

[0099] Ratio range of components in the high expansion rate epoxy resin formula:

[0100] Flexible raw materials (such as polyols, polyphenols with larger free volumes, etc.): Approximately 30% - 50%;

[0101] Crosslinking agent (such as amines, acid anhydrides, etc., specific types and dosages need to be adjusted according to the resin type): about 5%-15%;

[0102] Filler (such as certain inorganic salts, expandants, etc., used to increase volume or improve the coefficient of thermal expansion): about 10%-30%;

[0103] Other additives (such as catalysts, stabilizers, etc.): about 1%-5%;

[0104] Epoxy resin base resin: the remaining proportion to ensure the stability and processability of the overall formulation.

[0105] Proportion range of components in the low-expansion-rate epoxy resin formulation:

[0106] Rigid raw materials (such as rigid polyphenols, polyacids, etc.): about 40%-60%;

[0107] Crosslinking agent (select a type that can form a high crosslinking density and appropriately increase the dosage): about 10%-20%;

[0108] Filler (select a type with a low coefficient of thermal expansion, such as certain silicates, alumina, etc.): about 5%-20%;

[0109] Other additives: about 1%-5%;

[0110] Epoxy resin base resin: the remaining proportion, also ensuring the stability and processability of the overall formulation.

[0111] The flexible raw materials used in the examples of this application are flexible epoxy resin or plasticizer; the rigid raw materials are polystyrene or polyvinyl chloride; the crosslinking agent is ethylenediamine or diethylenetriamine or polyamide; the filler is expanded graphite or expanded perlite; other additives are diluent or thickener, and epoxy resin base resin.

[0112] Example 1

[0113] This example provides a fiber optic sensor interface for GIS, specifically three layers, including a central layer, a first additional layer, and a second additional layer. Among them, the central layer and the second additional layer adopt low-expansion-rate materials with an expansion rate b = 0.3%, and the first additional layer adopts a high-expansion-rate material with an expansion rate a = 1.5%. The interface treatment method is to use an adhesive, and the adhesive is an epoxy resin-based adhesive.

[0114] The preparation process includes the following steps:

[0115] S1. According to the design requirements, prepare epoxy resin formulation raw materials with different expansion rates;

[0116] The epoxy resin formulations for the central layer and the second additional layer are as follows: for the rigid raw materials with an expansion rate of 50%, crosslinking agent: 15%, filler: 10%, other additives: 3%, and epoxy resin base resin: 22%;

[0117] The epoxy resin formulation for the first additional layer is as follows: flexible raw materials: 40%, crosslinking agent: 10%, filler: 25%, other additives: 3%, and epoxy resin base resin: 22%;

[0118] S2. Design and manufacture a special injection mold according to the size and shape requirements of the interface;

[0119] S3. Inject the epoxy resin raw materials for the central layer into the central layer cavity of the mold for injection molding. After it is completely cured, polish, clean, and apply an adhesive to its surface;

[0120] Inject the epoxy resin raw materials for the first additional layer into the first additional layer cavity of the mold and ensure that it covers the surface of the central layer structure, then perform injection or compression molding. After it is completely cured, polish, clean, and apply an adhesive to its surface;

[0121] Repeat the above steps to complete the injection and curing process of the second additional layer;

[0122] Put the obtained multi-layer structure into a high-temperature oven for overall curing to complete the curing.

[0123] S4. After the overall curing is completed, take out the interface, polish and buff it. Process an optical fiber sensor installation hole and a sealing groove on the central layer, and fill it with a special sealant. The special sealant is an epoxy resin-based adhesive to obtain the optical fiber sensor interface for GIS.

[0124] S5. Install a flexible sleeve on the optical fiber. After passing through the optical fiber sensor installation port, perform secondary curing to obtain the optical fiber sensor interface for GIS.

[0125] Example 2

[0126] This example provides an optical fiber sensor interface for GIS, specifically four layers, including a central layer, a first additional layer, a second additional layer, and a third additional layer. Among them, the central layer and the second additional layer adopt materials with a low expansion rate, and the expansion rate b = 0.2%. The first additional layer and the third additional layer adopt materials with a high expansion rate, and the expansion rate a = 1.2%. The interface treatment method is to use an adhesive, and the adhesive is an epoxy resin-based adhesive.

[0127] The preparation process includes the following steps:

[0128] S1. Prepare epoxy resin formulation raw materials with different expansion rates according to the design requirements;

[0129] The epoxy resin formulations for the central layer and the second additional layer are as follows: for the rigid raw materials with a low expansion rate: 50%, crosslinking agent: 15%, filler: 10%, other additives: 3%, epoxy resin base resin: 22%;

[0130] The epoxy resin formulations for the first additional layer and the third additional layer are as follows: flexible raw materials: 40%, crosslinking agent: 10%, filler: 25%, other additives: 3%, epoxy resin base resin: 22%;

[0131] S2. Design and manufacture a special molding die according to the size and shape requirements of the interface;

[0132] S3. Arrange partition plates between each layer, inject epoxy resin raw materials respectively. After semi-curing, remove the partition plates and apply an adhesive;

[0133] The requirement for the semi-curing degree is that the liquid mixed raw materials between different layers will not flow into each other, resulting in the mixing of raw materials between layers. After removing the partition plates and adding the adhesive, the air gaps can be removed after the layers are fused together, and it is ensured that the layers are closely bonded after curing.

[0134] Put the obtained multi-layer structure into a high-temperature oven for overall curing treatment to complete the curing.

[0135] S4. After the overall curing is completed, take out the interface, grind and polish it, process optical fiber sensor mounting holes and sealing grooves on the central layer, and fill them with a special sealing glue. The special sealing glue is an epoxy resin-based adhesive to obtain the optical fiber sensor interface for GIS.

[0136] Example 3

[0137] This example provides an optical fiber sensor interface for GIS, specifically with five layers, including a central layer, a first additional layer, a second additional layer, a third additional layer, and a fourth additional layer. Among them, the central layer, the second additional layer, and the fourth additional layer adopt materials with a low expansion rate, and the expansion rate b = 0.4%. The first additional layer and the third additional layer adopt materials with a high expansion rate, and the expansion rate a = 1.8%. The interface treatment method is mechanical structure locking. The die has multiple combined annular cavities, and different combinations of the annular cavities are used to prepare the central layer and different additional layers. There are interface treatment grooves or convex mechanisms between different annular cavities. The preparation process includes the following steps:

[0138] S1. Prepare epoxy resin formulation raw materials with different expansion rates according to the design requirements;

[0139] The epoxy resin formulations for the central layer, the second additional layer, and the fourth additional layer are as follows: for the rigid raw materials with a low expansion rate: 50%, crosslinking agent: 15%, filler: 10%, other additives: 3%, epoxy resin base resin: 22%;

[0140] The epoxy resin formulations for the first additional layer and the third additional layer are as follows: flexible raw materials: 40%, crosslinking agent: 10%, filler: 25%, other additives: 3%, epoxy resin base resin: 22%.

[0141] S2. Design and manufacture a special injection mold according to the size and shape requirements of the interface, and process interface treatment grooves and protruding structures for locking in the mold.

[0142] S3. Inject the central layer epoxy resin raw material into the central layer cavity of the mold, carry out injection molding, and after it is completely cured, grind and clean its surface.

[0143] Inject the first additional layer epoxy resin raw material into the first additional layer cavity of the mold, and ensure that it covers the surface of the central layer structure, carry out injection or compression molding, and after it is completely cured, grind, clean and install the locking structure on its surface.

[0144] Repeat the above steps until the injection / molding and curing treatment of the fourth additional layer is completed.

[0145] Put the obtained multi-layer structure into a high-temperature oven for overall curing treatment to complete the curing.

[0146] S4. After the overall curing is completed, take out the interface, grind and polish it, process optical fiber sensor installation holes and sealing grooves on the central layer, and fill with a special sealing glue, and the special sealing glue is an epoxy resin-based adhesive to obtain the optical fiber sensor interface for GIS.

[0147] The above are only embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are all included within the scope of the claims of the present invention.

Claims

1. An optical fiber sensor interface for GIS, characterized in that, The interface is used for connecting a GIS device and an optical fiber sensor. The interface includes a central layer and at least one additional layer disposed around the central layer; The central layer is provided with an optical fiber sensor mounting opening; The central layer and each of the additional layers have different expansion rates.

2. The fiber optic sensor interface for GIS according to claim 1, characterized in that, When the additional layer is multiple layers, the number of layers of the additional layer is n, including a first additional layer adjacent to the central layer, a second additional layer adjacent to the first additional layer, and up to an nth additional layer adjacent to the (n - 1)th additional layer; Wherein, the expansion rate of the central layer is higher than that of the first additional layer, and the expansion rates of the central layer and the additional layers, as well as different additional layers, are arranged alternately in a high-low pattern layer by layer.

3. The fiber optic sensor interface for GIS according to claim 2, wherein In the alternately arranged central layer and additional layers, for any two adjacent layers, the expansion rate of the layer with a lower expansion rate is a, and the expansion rate of the layer with a higher expansion rate is b, where 0.1% ≤ a ≤ 0.5% and 0.5% ≤ b ≤ 2%.

4. The fiber optic sensor interface for GIS according to claim 1, characterized in that, The central layer and the additional layers are made of epoxy resin-based materials with different expansion rates.

5. An interface processing method for interlayer bonding treatment between the central layer and the additional layers of the fiber optic sensor interface for GIS described in any one of claims 1 to 4, and between the additional layers, characterized in that, It includes performing interlayer bonding treatment between the central layer and the additional layers, and between each additional layer using an adhesive or mechanical structure locking.

6. According to the interface treatment method described in claim 5, the adhesive is an epoxy resin-based adhesive.

7. According to the interface treatment method described in claim 5, the mechanical structure locking utilizes mechanical principles to apply a clamping force between layers by inserting mechanical jigs into each layer.

8. A curing process for curing the fiber optic sensor interface for GIS according to any one of claims 1 to 4, characterized in that, It includes the following steps: Inject the central layer epoxy resin raw material into the central layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface; Inject the additional layer epoxy resin raw material into the additional layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface; Put the obtained multi-layer structure into a high-temperature oven for overall curing treatment to complete the curing.

9. The curing process according to claim 8, characterized in that, When the additional layer is multiple layers: Inject the central layer epoxy resin raw material into the central layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface; Inject the first additional layer epoxy resin raw material into the first additional layer cavity of the mold. After it is cured and formed, polish, clean, and perform interface treatment on its surface; Repeat the above steps until the forming and curing treatment of the nth additional layer is completed; Put the obtained multi-layer structure into a high-temperature oven for overall curing treatment to complete the curing.

10. A curing process for curing the optical fiber sensor interface for GIS according to any one of claims 1 to 4, characterized in that, It includes the following steps: Arrange partitions between each layer, inject epoxy resin raw materials respectively. After semi-curing, remove the partitions, perform interface treatment, and finally perform overall curing treatment; The requirement for the semi-curing degree is that the liquid mixed raw materials between each layer do not flow into each other, and after removing the partitions and performing interface treatment, there is no air gap between each layer.

11. A method for preparing the optical fiber sensor interface for GIS according to any one of claims 1 to 4, characterized in that, It includes the following steps: Prepare epoxy resin raw materials with different expansion rates according to the design requirements; Design and manufacture a special mold according to the size and shape requirements of the optical fiber sensor interface for GIS; Inject epoxy resin raw materials with different expansion rates into the special mold, and perform curing and interface treatment; After curing is completed, take out the interface, polish it, and process an optical fiber sensor mounting hole and a sealing groove on the central layer, and fill it with a special sealing adhesive to obtain the optical fiber sensor interface for GIS.

12. The preparation method according to claim 11, characterized in that, It further includes that after obtaining the optical fiber sensor interface for GIS, pass the optical fiber sensor through the optical fiber sensor mounting opening and then perform secondary curing.

13. The preparation method according to claim 12, wherein, Install a flexible sleeve on the optical fiber, pass it through the optical fiber sensor mounting opening, and then perform secondary curing.

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