A method for manufacturing a post insulator

Abstract

The application discloses a manufacturing method of a post insulator, which comprises the following steps: step 1, providing a hollow insulating tube and two flanges, the inner diameter of the flanges being slightly smaller than the outer diameter of the hollow insulating tube; step 2, integrally coating the umbrella skirt on the outer surface of the hollow insulating tube; step 3, press-fitting and fixing the two flanges to the two ends of the hollow insulating tube through interference fit; and step 4, sealing the gap between the flanges and the hollow insulating tube to obtain the post insulator. The manufacturing method of the post insulator is simple, convenient and low in manufacturing cost, and is high in production efficiency and improves the connecting strength between the components of the post insulator.

Description

Technical Field

[0001] This invention relates to the field of insulation equipment technology for power transmission and transformation and offshore wind power new energy, and in particular to a method for manufacturing post insulators. Background Technology

[0002] Currently, the industry's post insulators include the following technical routes: ① ceramic insulators coated with room temperature vulcanizing (RTV) silicone rubber coating; ② ceramic core composite post insulators, i.e., the sheds are made of silicone rubber and the core rod is made of ceramic; ③ solid composite post insulators, i.e., using a solid core of composite materials; ④ hollow composite insulators filled with solid insulating medium; ⑤ hollow composite insulators filled with pressurized gas. The outer insulating sheds of the latter three are all made of silicone rubber.

[0003] To improve the mechanical properties of post insulators, it is necessary to propose a manufacturing method for post insulators and strengthen the connection between the various components of the post insulators. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for manufacturing post insulators, which has a simple manufacturing process, low manufacturing cost, high production efficiency, and improves the connection strength between the various components of the post insulator.

[0005] To achieve the above-mentioned objectives, the technical means adopted by this invention are as follows: A method for manufacturing a post insulator includes the following steps: Step ①: providing a hollow insulating tube and two flanges, the inner diameter of the flanges being slightly smaller than the outer diameter of the hollow insulating tube; Step ②: covering the hollow insulating tube with shed skirts; Step ③: fixing the two flanges to both ends of the hollow insulating tube by interference fit; Step ④: sealing the gap between the flanges and the hollow insulating tube with glue to obtain the post insulator.

[0006] Preferably, the flange includes a flange cylinder and a flange plate. The flange plate covers one end of the flange cylinder, thus sealing both ends of the hollow insulating tube and preventing moisture and other impurities from entering the post insulator. The flange plate is a closed flange plate, requiring no drilling, making it easy to process and providing good sealing performance.

[0007] Preferably, a first sealing groove is provided on the flange surface facing the hollow insulating tube. Before step ③, a first sealing element is provided in the first sealing groove to prevent gaps between the hollow insulating tube and the flange, thus avoiding external moisture from entering the hollow insulating tube and affecting the seal between the hollow insulating tube and the flange.

[0008] Preferably, the width of the first sealing groove remains constant or gradually decreases in the direction close to the hollow insulating tube, and an adhesive is applied to the first sealing groove and / or the first sealing element to prevent the first sealing element from falling off.

[0009] Preferably, before step ③, a drying device is installed on the flange facing the hollow insulating tube to remove moisture from the inside of the post insulator. The drying device includes a cage-shaped desiccant box and a desiccant placed inside the desiccant box. The outer periphery of the desiccant box is provided with through holes to absorb moisture.

[0010] Preferably, the desiccant is placed directly in a cage-shaped desiccant box and the drying device is fixed to the flange.

[0011] Preferably, the desiccant is packaged in a cloth bag.

[0012] Preferably, before step ③, an adhesive is applied to the outer wall of the hollow insulating tube and / or the inner wall of the flange.

[0013] Preferably, in step ③, the two flanges are directly fitted onto both ends of the hollow insulating tube, and the insulating medium inside the hollow insulating tube is ambient air.

[0014] Preferably, after step ③, the area where the hollow insulating tube is press-fitted to the flange is heated, cured, and cooled.

[0015] The beneficial effects of this application are as follows: Unlike existing technologies, the post insulator of this application has a hollow structure, meaning the core of the post insulator is made of a hollow insulating tube filled with ambient air. This avoids the cracking defects and interface problems that can occur with solid filling, thus affecting the electrical performance of the post insulator. Furthermore, since the ambient air is not filled through an inflation device, the inflation step is eliminated, and therefore no inflation device, such as an inflation valve, is needed on the flange. This simplifies the structure and reduces costs; compared to traditional structures, the overall cost is reduced by at least 30%, while also reducing the risk of air leakage and manufacturing defects. The post insulator does not generate negative pressure during operation, thus eliminating the need for monitoring devices, and the ambient air does not require special treatment (such as drying), resulting in improved overall performance. Simultaneously, the interference fit connection process, compared to existing technologies, improves the connection strength between the hollow insulating tube and the flange, enhances the reliability and convenience of the assembly process, increases the overall mechanical strength of the post insulator, and further improves the level of automated manufacturing for subsequent products. Attached Figure Description

[0016] Figure 1 This is a cross-sectional schematic diagram of a post insulator 10 according to an embodiment of the present invention;

[0017] Figure 2 This is a cross-sectional schematic diagram of flange 130 according to an embodiment of the present invention;

[0018] Figure 3 This is a cross-sectional schematic diagram of flange 130 according to another embodiment of the present invention;

[0019] Figure 4 In an implementation scenario Figure 1 An enlarged schematic diagram of part A in the middle;

[0020] Figure 5 In another implementation scenario Figure 1 An enlarged schematic diagram of part A in the middle. Detailed Implementation

[0021] As requested, specific embodiments of the invention are disclosed herein. However, it should be understood that the embodiments disclosed herein are merely typical examples of the invention, which may be embodied in various forms. Therefore, the specific details disclosed herein are not to be considered limiting, but merely serve as the basis for the claims and as a representative basis for teaching those skilled in the art to apply the invention differently in practice in any appropriate manner, including employing the various features disclosed herein in combination with features that may not be explicitly disclosed herein.

[0022] The term "connection" as used in this invention, unless otherwise explicitly specified or limited, should be interpreted broadly, encompassing both direct connection and connection via an intermediate medium. In the description of this invention, it should be understood that the orientations or positional relationships indicated by terms such as "upper," "lower," "end," and "one end" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and for simplification, not to 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 the invention.

[0023] like Figure 1 As shown, the post insulator 10 includes a hollow insulating tube 110, sheds 120, and two flanges 130. The sheds 120 completely cover the outer periphery of the hollow insulating tube 110, and the two flanges 130 respectively seal and cover both ends of the hollow insulating tube 110. The hollow insulating tube 110 can be a hollow insulating tube formed by pultrusion and winding of glass fiber or aramid fiber impregnated with epoxy resin, or it can be a fiberglass tube formed by winding and curing glass fiber impregnated with epoxy resin or by pultrusion, or it can be an aramid fiber tube formed by winding and curing aramid fiber impregnated with epoxy resin; no limitation is made here.

[0024] The shed 120 is made of silicone rubber and is wrapped around the outer periphery of the hollow insulating tube 110 by vacuum injection, thereby improving the external insulation performance and service life of the post insulator 10. Of course, the shed can also be made of other rubber materials or insulating materials, and the shed can also be fixed to the outer periphery of the hollow insulating tube by molding or other methods, which are not limited here.

[0025] In one application scenario, flange 130 includes flange cylinder 131 and flange plate 132. Flange cylinder 131 is hollow along the axial direction, and flange plate 132 covers one end of flange cylinder 131, making flange 130 a structure with one side open and the other side closed. The open sides of the two flange cylinders 131 are respectively fitted onto both ends of hollow insulating tube 110, and flange 130 seals and covers both ends of hollow insulating tube 110, that is, the post insulator 10 is in a fully enclosed state, preventing external moisture and other impurities from entering the interior of post insulator 10. Flange plate 132 is closed, requiring no drilling, making processing convenient and providing good sealing performance. At this time, the insulating medium inside hollow insulating tube 110 is ambient air, and the air pressure inside hollow insulating tube 110 is consistent with the air pressure of the production environment when manufacturing post insulator 10. Thus, post insulator 10 can be directly packaged in the production environment, which is convenient for production, requires no other treatment of the insulating medium, meets the insulation performance requirements, and has high production efficiency and low processing cost.

[0026] In one application scenario, compared to traditional solid post insulators and hollow air-filled post insulators, the post insulator 10, which uses ambient air as the internal insulation medium, avoids the cracking defects and interface problems caused by solid filling, thus affecting the electrical performance of the post insulator. On the other hand, since the ambient air is not filled by an inflation device, the inflation step is eliminated, and the inflation valve structure, inflation device, and gas are omitted, simplifying the structure and reducing costs. The overall cost is reduced by at least 30%, while reducing the risk of air leakage and process defects. The post insulator does not generate a negative pressure state during operation, so there is no need to install monitoring devices, and the ambient air does not need to be specially treated (such as drying treatment), thus improving the overall performance.

[0027] In one application scenario, the relative air pressure inside the hollow insulating tube 110 is set to 0 MPa.

[0028] It should be noted that in this embodiment, the flanges 130 at both ends of the hollow insulating tube 110 are exactly the same. In other embodiments, the flanges at both ends of the hollow insulating tube can also be set as two different flanges. For example, in order to adapt to different connection strengths, the heights of the two flanges are not the same, or in order to adapt to different connection methods, the positions and numbers of the connection holes on the flange are not the same, etc. There are no restrictions here.

[0029] Furthermore, in this embodiment, the flange 130 is made of aluminum alloy, and the flange cylinder 131 and flange plate 132 are integrally formed, that is, formed by integral casting, resulting in a relatively simple structure that is easy to manufacture. Of course, in other embodiments, the flange can also be made of steel or other metal materials, and the flange cylinder and flange plate can also be formed separately and then fixedly connected by welding; no limitation is imposed here.

[0030] Combination Figure 1 and Figure 2 As shown, in one application scenario, the hollow insulating tube 110 is fixed to two flanges 130 by adhesive bonding. Specifically, the outer diameter of the hollow insulating tube 110 is slightly smaller than the inner diameter of the flange cylinder 131. Several inner annular grooves 1311 are spaced apart along the axial direction of the flange cylinder 131 on the inner wall of the flange cylinder 131, and several outer annular grooves (not shown) are spaced apart along the axial direction of the hollow insulating tube 110 on the outer wall of the hollow insulating tube 110. The inner annular grooves 1311 and the outer annular grooves are identical in size and number. When the hollow insulating tube 110 is fitted into the flange cylinder 131 and one end of the hollow insulating tube 110 abuts against the flange plate 132 facing the surface of the hollow insulating tube 110, the positions of the inner annular grooves 1311 and the outer annular grooves match and correspond. Then, an injection hole (not shown) is made on the flange 130 to fill the space between the outer wall of the hollow insulating tube 110 and the flange 130 with adhesive. Specifically, after making an injection hole on the outer wall of the flange cylinder 131, adhesive is injected into the injection hole, filling the cavity formed by the inner annular groove 1311 and the outer annular groove, thereby connecting and fixing the hollow insulating tube 110 and the flange 130 with adhesive. The above-mentioned adhesive bonding method can be horizontal or vertical, as long as it can fix the flange 130 and the hollow insulating tube 110 with adhesive. In another application scenario, adhesive can also be applied to the outer wall of the hollow insulating tube 110 and / or the inner wall of the flange cylinder 131 before adhesive bonding.

[0031] Continue reading Figure 2 The inner wall of the flange cylinder 131 is also provided with a flow groove 1312 that connects several inner annular grooves 1311. After the adhesive is injected into the flange cylinder 131, it fills the flow groove 1312. After the adhesive in the inner annular grooves 1311 and the flow groove 1312 is cured, it forms a cross structure, which can further fix the flange cylinder 131 and the hollow insulating tube 110. It can also allow the adhesive injected between the flange cylinder 131 and the hollow insulating tube 110 to flow between adjacent inner annular grooves 1311, thereby increasing the injection rate, reducing the risk of air bubble retention, and making the connection between the flange 130 and the hollow insulating tube 110 more secure. Thus, the torsional resistance of the post insulator 10 can be improved without replacing it with an adhesive with better bonding performance.

[0032] The number of flow channels 1312 can be one or more (e.g., two, four, six or even more), and when there are multiple flow channels 1312, they are spaced apart circumferentially along the flange cylinder 131. A single flow channel 1312 can connect only two adjacent inner annular grooves 1311, or it can connect three, four, or even all of the adjacent inner annular grooves 1311; there is no limitation on this.

[0033] The bottom surface of the flow channel 1312 can be either flat or curved. Specifically, when the radial depth and width of the flow channel 1312 relative to the flange 130 are constant, the flow channel 1312 with a flat bottom surface is more complex to manufacture and has a higher manufacturing cost than the flow channel 1312 with a curved bottom surface, but it has higher torsional strength. This is because the adhesive in the flat channel has a larger contact area with the inner wall of the flange cylinder 131. In other words, the flow channel 1312 with a curved bottom surface is easier to manufacture and has a lower manufacturing cost than the flow channel 1312 with a flat bottom surface, but its torsional strength is slightly lower.

[0034] Furthermore, along the axial direction of the post insulator 10, the ratio of the length of the contact portion between the inner wall of the flange cylinder 131 and the hollow insulating tube 110 to the outer diameter of the hollow insulating tube 110 (i.e., the adhesive ratio) ranges from 0.2 to 1.0, for example, 0.2, 0.5, 0.8, or 1.0. Specifically, as the adhesive ratio decreases, the strength of the post insulator 10 will decrease significantly. For example, compared to an adhesive ratio of 0.2, when the adhesive ratio decreases to 0.15, the strength of the post insulator 10 will decrease by 20%. Compared to an adhesive ratio of 1.0, when the adhesive ratio increases to 1.2, although the strength of the post insulator 10 will increase slightly, the cost will increase significantly. Therefore, setting the adhesive ratio range to 0.2 to 1.0 allows the post insulator 10 to simultaneously possess the advantages of low cost and high strength.

[0035] Continue to combine Figure 1 and Figure 2 As shown, a first sealing groove 133 is provided on the flange 132 facing the hollow insulating tube 110. The first sealing groove 133 is located inside the flange cylinder 131, and a first sealing element (not shown) is provided in the first sealing groove 133. Specifically, the first sealing element is disposed in the first sealing groove 133. When one end of the hollow insulating tube 110 abuts against the flange 132 facing the hollow insulating tube 110, the first sealing element is sandwiched between the flange 132 and the end face of the hollow insulating tube 110, playing a sealing role, preventing gaps between the hollow insulating tube 110 and the flange cylinder 130, and preventing external moisture from entering the hollow insulating tube 110, thereby preventing excessive moisture content in the hollow insulating tube 110.

[0036] In one embodiment, when the hollow insulating tube 110 is fixed to the two flanges 130 by adhesive bonding, the inner wall of the flange cylinder 131 is also provided with a second sealing groove 134 adjacent to the flange 132, and a second sealing element (not shown) is provided in the second sealing groove 134. Specifically, the second sealing element has a different function from the first sealing element. The second sealing element is used to prevent the adhesive during the bonding process between the flange 130 and the hollow insulating tube 110 from entering the first sealing groove 133 and corroding the first sealing element, thereby preventing the first sealing element from failing and thus avoiding affecting the seal between the hollow insulating tube 110 and the flange 130.

[0037] It should be noted that in other embodiments, when the hollow insulating tube 110 is fixed to the two flanges 130 by adhesive, the second sealing groove and the second sealing element may not be provided. As long as the flange 130 is fitted into the end of the hollow insulating tube 110, the flange 132 and the end of the hollow insulating tube 110 are in full contact, so that the first sealing element is fully compressed, and the flange 132 and the end of the hollow insulating tube 110 are sealed, the adhesive during the adhesive bonding process cannot enter the contact surface between the flange 132 and the hollow insulating tube 110.

[0038] Combination Figure 1 , Figure 4 and Figure 5 The width of the first sealing groove 133 remains constant in the direction near the hollow insulating tube 110 (e.g. Figure 4 (as shown) or gradually decreases (as shown) Figure 5 (As shown). Specifically, the first sealing groove 133, whose width remains constant in the direction near the hollow insulating tube 110, is easy to process. However, the first sealing element inside it may slide or even fall off. In this case, to prevent the first sealing element from sliding relative to the first sealing groove 133, the first sealing element is also glued and fixed in the first sealing groove 133 with an adhesive, such as resin or silicone. Compared with the first sealing groove 133, whose width remains constant in the direction near the hollow insulating tube 110, the first sealing groove 133, whose width gradually decreases in the direction near the hollow insulating tube 110, is more complex to process, but it can ensure that the first sealing element will not easily fall off. Of course, this solution can also use an adhesive to glue and fix the first sealing element in the first sealing groove to further prevent the first sealing element from falling off. The width of the first sealing groove 133 can decrease linearly in the direction near the hollow insulating tube 110 (e.g., ...). Figure 4 As shown in the figure, it can also decrease in a curved manner (not shown in the figure), and there is no restriction here.

[0039] The second sealing groove 134 has the same structure as the first sealing groove 133, and will not be described again here.

[0040] In another application scenario, combined with Figure 1 and Figure 2 The hollow insulating tube 110 is fixedly connected to the two flanges 130 by interference fit. At this time, the outer diameter of the hollow insulating tube 110 is slightly larger than the inner diameter of the flange cylinder 131. The hollow insulating tube 110 is pressed into the flange cylinder 131 by a pressure device, so that the end face of the hollow insulating tube 110 abuts against the plate surface of the flange 132.

[0041] The flange 132 has a first sealing groove 133 on its surface facing the hollow insulating tube 110. The first sealing groove 133 is located inside the flange cylinder 131, and a first sealing element (not shown) is provided in the first sealing groove 133. Specifically, the first sealing element is disposed in the first sealing groove 133. When one end of the hollow insulating tube 110 abuts against the flange 132 facing the hollow insulating tube 110, the first sealing element is sandwiched between the flange 132 surface and the end face of the hollow insulating tube 110, playing a sealing role to prevent gaps between the hollow insulating tube 110 and the flange cylinder 130, and to prevent external moisture from entering the hollow insulating tube 110, thereby preventing excessive moisture levels inside the hollow insulating tube 110.

[0042] The outer wall of the hollow insulating tube 110 and / or the inner wall of the flange 131 are coated with adhesive to further enhance the connection strength between the hollow insulating tube 110 and the flange 130. The adhesive also further seals the tightly joined hollow insulating tube 110 and flange 131, thus eliminating the need for additional sealing structures between the outer wall of the hollow insulating tube 110 and the inner wall of the flange 131, i.e., eliminating the need for the aforementioned second sealing groove and second sealing element.

[0043] Specifically, when the hollow insulating tube 110 is fixedly connected to the two flanges 130 by an interference fit, the interference fit between the hollow insulating tube 110 and the flanges 130 allows them to be tightly joined together, so there is no need to set a second sealing groove. In addition, adhesive can be applied between the hollow insulating tube 110 and the flange 131 to further improve the connection strength between the hollow insulating tube 110 and the flange 131. At the same time, the adhesive between the hollow insulating tube 110 and the flange 131 can form a further seal to ensure the sealing effect.

[0044] Furthermore, when the hollow insulating tube 110 is fixedly connected to the two flanges 130 via an interference fit, since the adhesive is directly applied between the hollow insulating tube 110 and the flange 131, the inner wall of the flange 131 does not need to be provided with the aforementioned inner annular groove and flow groove. This further simplifies the structure of the flange 130, reduces process steps, improves production efficiency, and thus reduces costs. Of course, in other embodiments, the inner annular groove and flow groove can still be provided on the inner wall of the flange 131 to ensure that the adhesive is fully filled between the hollow insulating tube 110 and the flange 131, thereby improving the connection strength.

[0045] Continue reading Figure 1A drying device 140 is also provided on the flange 132 facing the hollow insulating tube 110 to remove moisture from the inside of the post insulator 10. The drying device 140 is located inside the hollow insulating tube 110 and includes a desiccant box 141 and a desiccant 142 placed inside the desiccant box 141. The structure is simple and easy to manufacture. Specifically, the desiccant box 141 is cage-shaped and is upside down on the flange 130, with the desiccant placed inside. A connecting lug (not shown) extends from the opening of the desiccant box 141 perpendicular to the desiccant box 141. Several connecting holes (not shown) are provided on the connecting lug for fixed connection with the flange 130 facing the hollow insulating tube 110.

[0046] It should be noted that in other embodiments, the drying device may also have other structures. For example, the desiccant box may not have connecting lugs, and the desiccant box may be fixed to the flange by welding. This is not a limitation. Furthermore, the drying device may have several lugs on both flanges.

[0047] The desiccant box 141 can be made of a conductive material, such as metal. The outer periphery of the desiccant box 141 has uniformly distributed through holes of the same size, forming a shielding cage. Utilizing the shielding cage principle, this ensures that the desiccant box 141 will not affect the internal electric field of the hollow insulating tube 110. Alternatively, the desiccant box can also be made of a non-conductive material, such as plastic.

[0048] It should be noted that in other embodiments, the material and shape of the desiccant box are not limited to this embodiment, nor are the distribution and size of the through holes, as long as they meet the requirements of the shielding cage. Furthermore, in the axial direction of the post insulator 10, the height of the drying device is set to be less than the height of the flange cylinder to avoid the metal drying device affecting the electric field distribution near the flange. Of course, the height of the drying device can also be set to be the same as or slightly higher than the height of the flange cylinder, as long as the drying device meets the shielding cage principle, i.e., it will not affect the internal electric field of the hollow insulating tube 110.

[0049] The desiccant is packaged in a cloth bag and tied up to prevent it from scattering.

[0050] In one application scenario, a cloth bag containing desiccant is fixed inside a desiccant box 141. To prevent the cloth bag from being bumped or damaged by external forces during transportation and installation of the post insulator 10, it can be fixed by binding or other methods.

[0051] In another application scenario, the fabric bag is made into a thin bag, maximizing the area of ​​the bag laid on the flange 132. This allows the desiccant to spread evenly inside the bag, maximizing its contact with the ambient air inside the hollow insulating tube 110, effectively absorbing moisture and improving drying performance. Preferably, the area of ​​the bag laid flat is equal to the cross-sectional area of ​​the desiccant box 141. Furthermore, cross-shaped or star-shaped quilting is made on the bag to form several small grids, each filled with desiccant. This ensures uniform filling of the desiccant and a consistent and stable contact area with the ambient air inside the hollow insulating tube 110, better maximizing the drying effect. It also prevents the desiccant from accumulating in one spot due to gravity, thus affecting its adsorption efficiency.

[0052] Combination Figure 1 and Figure 2 As shown, in one application scenario, the flange 132 has a uniform thickness, and the drying device 140 is fixed on the flange 132 facing the hollow insulating tube 110. The drying device 140 can be fixed to the flange 132 by welding, gluing, screwing, etc. Furthermore, when using screwing, screw holes need to be provided on the flange 132. Drilling holes will affect the mechanical properties of the flange 132 to some extent. Therefore, in another application scenario, the thickness of the flange 132 can be increased to achieve better mechanical properties.

[0053] Combination Figure 1 and Figure 3 As shown, in another application scenario, a boss 1321 is provided on the side of the flange 132 near the hollow insulating tube 110. The drying device 140 is fixedly connected to the boss 1321. This eliminates the need to increase the overall thickness of the flange 132, thus avoiding the impact of the screw holes 1322 on the mechanical properties of the flange 132, resulting in better economic efficiency. Specifically, the boss 1321 is coaxially arranged with the flange 132, extending along the axial direction of the flange 130 away from the flange 132. The outer diameter of the boss 1321 is smaller than the inner diameter of the flange 131. Specifically, the outer diameter of the boss 1321 only needs to be slightly larger than or equal to the outer diameter of the drying device 140 to facilitate fixing the drying device 140. In this way, a stepped surface is formed between the boss 1321 and the flange 132 facing the hollow insulating tube 110, minimizing the material used in the flange 130, saving costs and reducing the weight of the flange 130. At this time, screw holes 1322 are provided on boss 1321, that is, the drying device 140 is connected and fixed to boss 1321. Assume the height of boss 1321 protruding from flange 132 towards the surface of hollow insulating tube 110 is H (e.g., Figure 3As shown in the diagram, the depth of H is consistent with that of the screw hole 1322. This prevents the screw hole 1322 from affecting the mechanical properties of the flange 130 and avoids excessive material waste, resulting in good economic efficiency. Meanwhile, the surface of the boss 1321 can be circular like the flange 132, or it can be other shapes, such as square or rhomboid. The boss 1321 and the flange 132 can be integrally formed or fixedly connected in other ways; no restrictions are placed here. The screw holes 1322 on the boss 1321 correspond to the connecting holes. After the connecting holes and screw holes 1322 are matched, screws are inserted to fix the drying device 140 to the flange 130.

[0054] Furthermore, in an implementation scenario, combined with Figures 1-5 A method for manufacturing the post insulator 10 is provided as follows:

[0055] S101: Provides a hollow insulating tube 110 and two flanges 130, the inner diameter of the flanges 130 being slightly smaller than the outer diameter of the hollow insulating tube 110.

[0056] S102: The umbrella skirt 120 is completely wrapped around the hollow insulating tube 110.

[0057] S103: The two flanges 130 are press-fitted to both ends of the hollow insulating tube 110 by interference fit.

[0058] S104: Seal the gap between flange 130 and hollow insulating tube 110 to obtain post insulator 10.

[0059] Specifically, in S101, firstly, when manufacturing the hollow insulating tube 110, a release agent is coated on the surface of the core mold, the composite material is wound around, and glue is applied at the same time. When the thickness of the hollow insulating tube 110 reaches the preset value, the winding is stopped, and then it is cured and machined to obtain the hollow insulating tube 110.

[0060] It should be noted that the composite material is glass fiber or aramid fiber impregnated with epoxy resin. In this embodiment, the hollow insulating tube 110 is wound and formed by composite material winding. In other embodiments, it can also be wound and formed by composite material pultrusion, or only pultrusion forming, and there is no limitation here.

[0061] Secondly, the flange 130 is integrally cast from a metal material, such as aluminum, steel, or iron. The flange 130 includes a flange cylinder 131 and a flange plate 132. Alternatively, the flange cylinder 131 and the flange plate 132 can be separately formed and then welded together to form the flange 130; there is no limitation on this. The flange cylinder 131 has a hollow structure along the axial direction, and the flange plate 132 covers one end of the flange cylinder 131, making the flange 130 a structure with one side open and the other side closed.

[0062] Furthermore, a first sealing groove 133 is provided on the flange 132 facing the hollow insulating tube 110, and a first sealing element (not shown) is provided within the first sealing groove 133. Meanwhile, the width of the first sealing groove 133 remains constant in the direction approaching the hollow insulating tube 110 (e.g., ...). Figure 3 (as shown) or gradually decreases (as shown) Figure 4 (As shown). The first sealing element can be set before proceeding to S103 to ensure a seal, and it is not limited to being done in S101.

[0063] It should be noted that in other embodiments, the inner wall of the flange cylinder 131 may also be provided with the aforementioned second sealing groove 134 adjacent to the flange 132 and the second sealing element, and the inner wall of the flange cylinder 131 may also be provided with the aforementioned plurality of inner annular grooves 1311 spaced apart along the axial direction of the flange cylinder 131 and a flow groove together with the plurality of inner annular grooves 1311, so as to further improve the seal between the flange 130 and the hollow insulating tube 110. Specific details will not be elaborated further. Furthermore, a drying device 140 is provided on the flange 132 of one of the flanges 130 facing the hollow insulating tube 110. The drying device 140 includes a cage-shaped desiccant box 141 and a desiccant 142 placed inside the desiccant box 141. Alternatively, a drying device 140 may be provided on both flanges 130, as long as the internal dryness of the post insulator 10 can be ensured. The desiccant box 141 can be made of conductive material and has uniformly distributed through holes of the same size to form a shielding cage. Utilizing the shielding cage principle, this ensures that the desiccant box 141 will not affect the internal electric field of the hollow insulating tube 110. Alternatively, the desiccant box can be made of non-conductive material, such as plastic. The drying device 140 can be set up before step S103, and is not limited to being done in step S101.

[0064] Among them, the flange 132 facing the hollow insulating tube 110 is provided with a boss 1321. The drying device 140 is fixedly connected to the boss 1321. The boss 1321 is coaxially arranged with the flange 132. The boss 1321 extends away from the flange 132 along the axial direction of the flange 130. The outer diameter of the boss 1321 is smaller than the inner diameter of the flange 131. Thus, a stepped surface is formed between the boss 1321 and the flange 132 facing the hollow insulating tube 110.

[0065] Finally, the outer diameter of the hollow insulating tube 110 is set to be slightly larger than the inner diameter of the flange 131, so that the connection between the hollow insulating tube 110 and the flange 131 can be made stable through interference fit.

[0066] Furthermore, in S102, an injection molding machine is provided. After the hollow insulating tube 110 is coated with a coupling agent, it is placed into the mold of the injection molding machine. By adding silicone rubber raw material, the umbrella skirt 120 is integrally injected around the outer periphery of the hollow insulating tube 110.

[0067] It should be noted that in this embodiment, the umbrella skirt 120 is fixed to the outer periphery of the hollow insulating tube 110 by injection. In other embodiments, the umbrella skirt can also be fixed to the outer periphery of the hollow insulating tube 110 by molding or other means. The umbrella skirt can also be made of other rubber materials, and there are no restrictions here.

[0068] Before proceeding to S103, an adhesive is applied to the outer wall of the hollow insulating tube 110 and / or the inner wall of the flange cylinder 131. Then, S103 is performed. Specifically, a pressure device is provided to press the hollow insulating tube 110 into the flange cylinder 131, i.e., the hollow insulating tube 110 and the two flanges 130 are fixedly connected by an interference fit. After S103, the area where the hollow insulating tube 110 and the flanges 130 are pressed and fixed is heated, cured, and cooled to finally fix the hollow insulating tube 110 and the flanges 130. After the adhesive applied to the outer wall of the hollow insulating tube 110 and / or the inner wall of the flange cylinder 131 is cured, a seal is further formed between the tightly connected hollow insulating tube 110 and the flange cylinder 131. Therefore, it is not necessary to set other sealing structures between the outer wall of the hollow insulating tube 110 and the inner wall of the flange cylinder 131, such as the aforementioned second sealing groove 134 and second sealing element adjacent to the flange 132 on the inner wall of the flange cylinder 131. Two flanges 131 are respectively fitted onto the two ends of the hollow insulating tube 110, so that the two flanges 130 respectively seal and cover the two ends of the hollow insulating tube 110, that is, the post insulator 10 is in a fully enclosed state. At this time, the insulating medium inside the hollow insulating tube 110 is the untreated ambient air, that is, the ambient air in the space where the post insulator 10 is produced, and the air pressure value inside the hollow insulating tube 110 is consistent with the air pressure value of the production environment when the post insulator 10 is prepared. In this way, the post insulator 10 can be directly encapsulated in the production environment, which is convenient for production, requires no other treatment of the insulating medium, meets the insulation performance requirements, and has high production efficiency and low processing cost.

[0069] In S104, the end of the flange cylinder 131 furthest from the flange 132 is also provided with a sealing groove 1313. After the flange cylinder 131 is fitted onto the end of the hollow insulating tube 110, a gap (not shown) is formed between the flange cylinder 131 and the hollow insulating tube 110. A third sealing element (not shown) is placed in the gap and then fixed with sealant. In this way, the hollow insulating tube 110 and the flange 130 are sealed by three layers: the first sealing element, the adhesive seal between the hollow insulating tube 110 and the flange cylinder 131, and the third sealing element, forming a three-layer sealing structure. This further improves the overall sealing performance of the post insulator 10 and prevents external moisture from entering the interior of the post insulator 10.

[0070] The sealant can be room temperature vulcanizing silicone rubber or other materials that can cure at room temperature, as long as it can ensure that the third seal is reliable.

[0071] The beneficial effects of this application are as follows: Unlike the prior art, the post insulator 10 of this application has a hollow structure, that is, the core of the post insulator 10 is a hollow insulating tube 110, and the interior of the hollow insulating tube 110 is filled with ambient air. On the one hand, this avoids the cracking defects and interface problems caused by filling with solids, which would affect the electrical performance of the post insulator 10. On the other hand, since the ambient air is not filled by an inflation device, the inflation step is eliminated, and therefore no inflation device, such as an inflation valve, is needed on its flange 130. This simplifies the structure and reduces costs. Compared with the traditional structure, the overall cost is reduced by at least 30%, while reducing the risk of air leakage and process defects. The post insulator 10 will not generate a negative pressure state during operation, so no monitoring device is needed, and the ambient air does not need to be specially treated (such as drying treatment), thus improving the overall performance. Meanwhile, the interference fit connection process, compared with the existing technology, can improve the connection strength between the hollow insulating tube 110 and the flange 130, improve the reliability and convenience of the assembly process, improve the overall mechanical strength of the post insulator 10, and further improve the level of automated manufacturing of subsequent products.

[0072] The technical content and features of this invention have been disclosed above. However, it is understood that, under the inventive concept of this invention, those skilled in the art can make various changes and improvements to the above-described structures and materials, including combinations of the technical features disclosed or claimed herein, and explicitly including other combinations of these features. All such modifications and / or combinations fall within the technical field of this invention and are within the scope of protection of the claims of this invention.

Claims

1. A method for manufacturing a post insulator, comprising the following steps: Step ①: Provide a hollow insulating tube and two flanges. The inner diameter of the flange is slightly smaller than the outer diameter of the hollow insulating tube. The flange includes a flange cylinder and a flange plate. The flange plate covers one end of the flange cylinder. The flange plate has a first sealing groove on its plate surface facing the hollow insulating tube. The inner wall of the flange cylinder has a second sealing groove adjacent to the flange plate. Step 2: Cover the hollow insulating tube with an umbrella skirt; Step ③: The two flanges are respectively press-fitted to both ends of the hollow insulating tube using an interference fit, wherein, The two flanges are directly fitted onto both ends of the hollow insulating tube. The insulating medium inside the hollow insulating tube is ambient air. The air pressure inside the hollow insulating tube is consistent with the production environment air pressure during the preparation of the post insulator, so that the relative air pressure inside the hollow insulating tube is 0 MPa. Before this step, a first sealing element is set in the first sealing groove, a second sealing element is set in the second sealing groove, and a plurality of inner annular grooves and a flow groove connecting the plurality of inner annular grooves are spaced apart along the axial direction of the flange cylinder on the inner wall of the flange cylinder. Along the axial direction of the post insulator, the ratio of the length of the inner wall of the flange cylinder in contact with the hollow insulating tube to the outer diameter of the hollow insulating tube is set to be in the range of 0.2 to 1.

0. Adhesive is filled in the inner annular grooves and the flow groove to fix the flange cylinder and the hollow insulating tube. Step 4: Seal the gap between the flange and the hollow insulating tube to obtain the post insulator.

2. The post insulator as described in claim 1, characterized in that, The width of the first sealing groove remains constant or gradually decreases in the direction close to the hollow insulating tube, and an adhesive is applied inside the first sealing groove and / or on the first seal.

3. The post insulator as described in claim 1, characterized in that, Before step ③, a drying device is installed on the flange facing the hollow insulating tube. The drying device includes a cage-shaped desiccant box and a desiccant placed inside the desiccant box. The outer periphery of the desiccant box is provided with through holes.

4. The post insulator as described in claim 3, characterized in that, The desiccant is placed directly in the cage-shaped desiccant box and the drying device is fixed to the flange.

5. The method for manufacturing a post insulator as described in claim 4, characterized in that, The desiccant is packaged in a cloth bag.

6. The method for manufacturing a post insulator as described in claim 1, characterized in that, Before step ③, an adhesive is applied to the outer wall of the hollow insulating tube and / or the inner wall of the flange.

7. The method for manufacturing a post insulator as described in claim 6, characterized in that, After step ③, the area where the hollow insulating tube is press-fitted to the flange is heated, cured, and cooled.

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