A silicone rubber cold shrink outdoor terminal

Abstract

The utility model relates to silicon rubber cold contraction outdoor terminal technical field, specifically disclose a kind of silicon rubber cold contraction outdoor terminal, including terminal body, the outer skin of terminal body is equipped with, the outer skin is sequentially composed by inner layer insulation reinforcing layer, intermediate stress dispersion layer, main insulation layer, protective reinforcement layer and outer weatherable coating from inside to outside;In the utility model, outer weatherable coating can effectively resist the erosion of environmental factors such as ultraviolet, acid rain, salt fog, greatly slow down the aging speed of silicon rubber material, protective reinforcement layer can effectively absorb and disperse external mechanical external force impact, inner layer insulation reinforcing layer and main insulation layer can effectively improve the electric field distribution of cable terminal part, reduce local electric field concentration phenomenon, reduce partial discharge risk, outer weatherable coating has good self-cleaning performance, can reduce dust, dirt etc. Adhesion on terminal surface, reduce the accumulation speed of dirt on surface.

Description

Technical Field

[0001] This utility model relates to the field of silicone rubber cold shrink outdoor terminal technology, and in particular to a silicone rubber cold shrink outdoor terminal. Background Technology

[0002] In power transmission networks, silicone rubber cold-shrink outdoor terminals are key components connecting cables to external electrical equipment, and their outer sheath structure plays a decisive role in the overall performance of the terminal. As power systems develop towards higher voltage and larger capacity, outdoor terminals face more complex and demanding operating environments, including long-term ultraviolet radiation, high and low temperature cycling, acid rain and salt spray corrosion, mechanical impact, and thermal effects generated by strong electric fields and large currents.

[0003] Traditional silicone rubber cold-shrink outdoor terminal sheaths mostly adopt a single-layer or simple double-layer structure. A single-layer silicone rubber sheath relies on the properties of a single material to resist the external environment. Under long-term ultraviolet radiation, silicone rubber is prone to aging and cracking, leading to a decline in insulation performance. Utility Model Content

[0004] In view of the technical problem that traditional silicone rubber cold-shrink outdoor terminals mostly adopt a single-layer or simple double-layer structure for their outer skin, this utility model provides a silicone rubber cold-shrink outdoor terminal.

[0005] The technical solution adopted by this utility model is: a silicone rubber cold shrink outdoor terminal, including a terminal body, the terminal body is covered with an outer skin, and the outer skin is composed of an inner insulating reinforcement layer, an intermediate stress dispersion layer, a main insulating layer, a protective reinforcement layer and an outer weather-resistant coating from the inside to the outside.

[0006] A further feature of this invention is that the inner insulating reinforcement layer is made of a material composed of ethylene-vinyl acetate copolymer and nano-silica.

[0007] A further feature of this invention is that the thickness of the inner insulating reinforcement layer is 0.3-0.5 mm.

[0008] A further feature of this invention is that the intermediate stress dispersion layer is a composite material made of silicone rubber as the matrix and chopped glass fibers and organosilicon elastomers.

[0009] A further feature of this invention is that the thickness of the intermediate stress dispersion layer is 0.8-1.2 mm.

[0010] A further feature of this invention is that the main insulating layer is made of vinyl silicone rubber material.

[0011] A further feature of this invention is that the thickness of the main insulating layer is 2-3 mm.

[0012] A further feature of this invention is that the protective reinforcement layer is woven from aramid fiber or glass fiber, and the thickness of the protective reinforcement layer is 0.5-0.8 mm.

[0013] A further feature of this invention is that the outer weather-resistant coating is composed of a fluorinated organosilicon resin as the base material, with the addition of nano-titanium dioxide and nano-zinc oxide materials.

[0014] The beneficial effects of this utility model are as follows: In this utility model, the outer weather-resistant coating can effectively resist the erosion of environmental factors such as ultraviolet rays, acid rain, and salt spray, greatly slowing down the aging rate of silicone rubber materials. The protective reinforcement layer can effectively absorb and disperse the impact of external mechanical forces. The inner insulation reinforcement layer and the main insulation layer can effectively improve the electric field distribution at the cable terminal, reduce the phenomenon of local electric field concentration, and reduce the risk of partial discharge. The outer weather-resistant coating has good self-cleaning properties, which can reduce the adhesion of dust and dirt on the terminal surface and reduce the accumulation rate of dirt on the surface. In summary, in this utility model, the terminal body is not prone to aging and cracking even under long-term ultraviolet radiation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the layered structure of the outer skin in this utility model; Figure 3 yes Figure 2 A magnified structural diagram of region A in the middle.

[0016] The diagram is marked as follows: 1. Terminal body; 2. Outer sheath; 21. Inner insulation reinforcement layer; 22. Intermediate stress dispersion layer; 221. Main insulation layer; 23. Protective reinforcement layer; 24. Outer weather-resistant coating. Detailed Implementation

[0017] In the description of this utility model, it should be noted that the terms "front", "up", "down", "left", "right", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0018] The following is in conjunction with the appendix Figure 1-3 The present invention will be further described below.

[0019] To address the problems existing in the background technology, this application proposes the following technical solution: a silicone rubber cold shrink outdoor terminal, comprising a terminal body 1, characterized in that the terminal body 1 is covered with an outer skin 2, the outer skin 2 being composed of an inner insulating reinforcement layer 21, an intermediate stress dispersion layer 22, a main insulating layer 221, a protective reinforcement layer 23 and an outer weather-resistant coating 24 from the inside to the outside.

[0020] The specific explanation of the above technical solution is as follows: The inner insulation reinforcement layer 21 is tightly fitted to the internal insulation components of the cable terminal, mainly serving to enhance electrical insulation performance and buffer internal stress. This layer adopts a dense mesh structure, which can effectively disperse the concentrated force generated inside the cable terminal by electric field and mechanical stress, preventing the occurrence of local insulation weak points.

[0021] The inner insulating reinforcement layer 21 is made of a high-purity ethylene-vinyl acetate copolymer (EVA) and nano-silica. EVA has good flexibility and electrical insulation properties. The addition of nano-silica can significantly improve the strength, hardness and aging resistance of the material, while improving the dielectric properties of the material and making the electric field distribution more uniform.

[0022] Thickness: This layer is 0.3-0.5mm thick. This thickness ensures good insulation reinforcement without compromising the shrinkage performance and ease of installation of the cold-shrink terminal due to excessive thickness.

[0023] Production method: Extrusion molding process is adopted. EVA and nano-silica are mixed evenly in a certain proportion and then added to an extruder. Under high temperature and high pressure, the mixture is extruded through a die to form a continuous tubular structure. During the extrusion process, parameters such as temperature, pressure, and traction speed are strictly controlled to ensure the uniformity of tube thickness and dimensional accuracy. After the formed tube is cooled and shaped, it can be used as the inner insulation reinforcement layer 21 for later use.

[0024] The intermediate stress dispersion layer 22 is located outside the inner insulation reinforcement layer 21. Its main function is to further disperse the mechanical and thermal stresses experienced by the cable terminal during operation, preventing stress concentration from causing damage to the outer sheath 2 structure. This layer adopts a honeycomb porous structure, with optimized cell size and shape to effectively absorb and disperse stress.

[0025] Intermediate stress dispersion layer 22 material: Based on silicone rubber, with added chopped glass fibers and silicone elastomers. Silicone rubber provides good flexibility and weather resistance, chopped glass fibers enhance the mechanical strength of the material, and silicone elastomers improve the elasticity and stress absorption properties of the material, enabling this layer to maintain good performance under different stress conditions.

[0026] Thickness: The thickness is set at 0.8-1.2mm. This thickness ensures sufficient stress dispersion while forming a stable structural system in conjunction with other layers.

[0027] Production Method: Compression molding is employed. First, silicone rubber, chopped glass fiber, and silicone elastomer are mixed evenly according to the formula to prepare a premix. Then, the premix is ​​placed into a mold cavity and molded under specific temperature and pressure, allowing the material to solidify into a sheet-like component with a honeycomb-like porous structure. After molding, post-processing steps such as trimming and polishing are performed to remove excess material and ensure the dimensions meet design requirements.

[0028] The main insulation layer 221 is the core layer of the outer sheath 2 structure, undertaking the main electrical insulation function and providing necessary mechanical support for the cable terminal. This layer is a solid structure with excellent electrical insulation performance and mechanical strength.

[0029] Main insulation layer 221 material: High-performance vinyl silicone rubber is selected, with the addition of flame retardants such as aluminum hydroxide and magnesium hydroxide, as well as fumed silica as a reinforcing agent. Vinyl silicone rubber has good electrical insulation properties, weather resistance and processability. The addition of flame retardants gives the material flame-retardant properties, improving the fire safety performance of the cable terminal. Fumed silica can significantly enhance the mechanical strength and wear resistance of the material.

[0030] Thickness: Depending on the voltage level and insulation requirements of the cable termination, the thickness of the main insulation layer 221 is generally 2-3mm. For high-voltage cable terminations, the thickness can be appropriately increased to meet higher insulation performance requirements.

[0031] Production method: A process combining extrusion molding and vulcanization is employed. The prepared vinyl silicone rubber compound is fed into an extruder and extruded through a die into a tubular structure. The extruded tubing undergoes vulcanization in a high-temperature vulcanization unit, causing the silicone rubber to cross-link and form an elastomer with stable physicochemical properties. During vulcanization, parameters such as temperature, time, and pressure are strictly controlled to ensure uniform vulcanization and improve the performance consistency of the main insulation layer 221.

[0032] The protective reinforcement layer 23 is located outside the main insulation layer 221 and is mainly used to enhance the mechanical protection capability of the outer sheath 2, resisting external mechanical impacts, scratches, and abrasions. This layer adopts a fiber braided reinforcement structure, with the interwoven fibers forming a dense network that can effectively disperse and absorb external impact forces.

[0033] The protective reinforcement layer 23 is made of high-strength aramid fibers or glass fibers, which are then impregnated with silicone rubber. Aramid fibers or glass fibers have high strength and high modulus, providing good mechanical protection. The impregnation with silicone rubber ensures that the fibers are tightly bonded to the main insulation layer 221, while also giving the protective reinforcement layer 23 a certain degree of flexibility and weather resistance.

[0034] Thickness: 0.5-0.8mm. This thickness ensures sufficient mechanical protection without making the outer sheath 2 too thick, which would affect the installation and use of the cold shrink terminal.

[0035] Production method: First, aramid fibers or glass fibers are woven into a fiber fabric of predetermined size and shape using fiber weaving equipment. Then, the fiber fabric is impregnated with silicone rubber solution to ensure full absorption of the solution. After impregnation, the fiber fabric is dried to remove the solvent before being laminated with the main insulation layer 221. The lamination process can employ a hot-pressing process, where the silicone rubber solution is cured under specific temperature and pressure, firmly bonding the protective reinforcement layer 23 to the outside of the main insulation layer 221.

[0036] Among them, the outer weather-resistant coating 24 is the outermost layer of the outer skin 2, which is in direct contact with the external environment. Its main function is to resist the erosion of environmental factors such as ultraviolet rays, acid rain, and salt spray. At the same time, it has good self-cleaning properties, reduces the adhesion of dust and dirt on the terminal surface, and improves the anti-flashover capability.

[0037] Materials: Fluorinated silicone resin is used as the base material, with the addition of UV stabilizers such as nano-titanium dioxide and nano-zinc oxide, as well as silicone leveling agents and other additives. The fluorinated silicone resin possesses excellent weather resistance, chemical corrosion resistance, and self-cleaning properties. Nano-titanium dioxide and nano-zinc oxide effectively absorb and scatter ultraviolet rays, protecting the internal materials from UV damage. The silicone leveling agent makes the coating surface smoother and more even, improving the coating's uniformity and protective effect.

[0038] Thickness: The coating thickness is controlled between 0.05-0.1mm. A thinner coating can ensure good weather resistance and protection without affecting the overall flexibility and cold shrinkage performance of the outer skin 2.

[0039] Production method: A spraying process is adopted. The prepared fluorinated silicone resin coating is uniformly sprayed onto the surface of the outer skin 2 and the protective reinforcement layer 23 using a high-pressure spray gun. During the spraying process, parameters such as the pressure, distance, and moving speed of the spray gun are controlled to ensure that the coating thickness is uniform. After spraying, the outer skin 2 is baked and cured at a certain temperature to form a dense protective film that is firmly bonded to the protective reinforcement layer 23.

[0040] In a further design, the inner insulating reinforcement layer 21 is tightly connected to the intermediate stress dispersion layer 22 via a hot-pressing bonding process. During the hot-pressing process, the EVA material on the surface of the inner insulating reinforcement layer 21 is slightly melted by high temperature, allowing it to interpenetrate with the silicone rubber material on the surface of the intermediate stress dispersion layer 22, forming a strong bond upon cooling. The intermediate stress dispersion layer 22 is bonded to the main insulating layer 221 using a chemical adhesive. After the intermediate stress dispersion layer 22 is formed, a layer of special silicone rubber adhesive is evenly applied, and then the main insulating layer 221 is bonded to the intermediate stress dispersion layer 22. The strong connection between the two layers is achieved through the curing reaction of the adhesive. The protective reinforcement layer 23 is connected to the main insulating layer 221 via a hot-pressing composite process. During the hot-pressing process, the silicone rubber liquid impregnated in the fiber fabric of the protective reinforcement layer 23 melts upon heating, fusing with the silicone rubber material on the surface of the main insulating layer 221, forming an integrated structure upon cooling. The outer weather-resistant coating 24 is directly adhered to the surface of the protective reinforcement layer 23 via a spraying process. The resin component in the coating undergoes physical and chemical bonding with the silicone rubber material on the surface of the protective reinforcement layer 23, forming a stable coating structure. Through these connection methods, the five-layer structure of the outer skin 2 is tightly bonded, forming a high-performance and fully functional whole.

[0041] The outer weather-resistant coating 24 uses fluorinated organosilicon resin and nano-anti-UV agents, which can effectively resist the erosion of environmental factors such as ultraviolet rays, acid rain, and salt spray, and greatly slow down the aging rate of silicone rubber materials.

[0042] The protective reinforcement layer 23 is made of high-strength aramid fiber or glass fiber woven structure, combined with the honeycomb porous structure of the intermediate stress dispersion layer 22, which can effectively absorb and disperse the impact of external mechanical forces.

[0043] The materials used in the inner insulation reinforcement layer 21 and the main insulation layer 221 have excellent dielectric properties, which can effectively improve the electric field distribution at the cable termination, reduce local electric field concentration, and lower the risk of partial discharge. Meanwhile, the honeycomb porous structure of the intermediate stress dispersion layer 22 and the fiber braided structure of the protective reinforcement layer 23 facilitate heat dissipation, improving the heat dissipation performance of the cable termination. This ensures that the temperature of the termination remains within a reasonable range during high-load operation, slows down the aging rate of the insulation material, and guarantees the stable operation of the cable termination.

[0044] Through various bonding processes such as hot-press bonding, chemical adhesive bonding, and hot-press composite, a strong bond is formed between the layers of the outer sheath 2, preventing delamination during long-term environmental changes and operation. High and low temperature cycling tests and mechanical vibration tests have demonstrated that the bonding force between the layers remains excellent, ensuring the integrity and overall performance of the outer sheath 2 structure and improving the reliability and stability of the cable terminal.

[0045] The outer weather-resistant coating 24 has excellent self-cleaning properties, reducing the adhesion of dust and dirt to the terminal surface and slowing down the accumulation rate of contaminants. When operating in polluted environments, the anti-flashover performance of this outer skin 2 structure is significantly improved compared to traditional outer skin 2, effectively reducing the probability of flashover accidents and ensuring the safe operation of the power system.

[0046] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0047] Although embodiments of the present invention have been shown and described, the scope of the present invention will be defined by the appended claims and their equivalents for those skilled in the art.

Claims

1. A silicone rubber cold-shrink outdoor terminal, comprising a terminal body (1), characterized in that, The terminal body (1) is covered with an outer skin (2), which consists of an inner insulating reinforcement layer (21), an intermediate stress dispersion layer (22), a main insulating layer (221), a protective reinforcement layer (23), and an outer weather-resistant coating layer (24) from the inside to the outside.

2. The silicone rubber cold-shrink outdoor terminal according to claim 1, characterized in that, The thickness of the inner insulating reinforcement layer (21) is 0.3-0.5 mm.

3. The silicone rubber cold-shrink outdoor terminal according to claim 1, characterized in that, The thickness of the intermediate stress dispersion layer (22) is 0.8-1.2 mm.

4. The silicone rubber cold-shrink outdoor terminal according to claim 1, characterized in that, The main insulating layer (221) is made of vinyl silicone rubber material.

5. A silicone rubber cold-shrink outdoor terminal according to claim 1, characterized in that, The thickness of the main insulating layer (221) is 2-3 mm.

6. A silicone rubber cold-shrink outdoor terminal according to claim 1, characterized in that, The protective reinforcement layer (23) is woven from aramid fiber or glass fiber, and the thickness of the protective reinforcement layer (23) is 0.5-0.8 mm.

Images