Composite insulator

Abstract

The application discloses a composite insulator, which comprises an insulating tube, an outer wall of an end of the insulating tube is provided with at least one first annular groove; a flange, the flange comprises a flange tube and a flange plate, an inner wall of the flange tube is provided with at least one second annular groove and at least one annular sealing groove, the second annular groove is arranged correspondingly with the first annular groove to cooperatively form a fixing groove, wherein a radial section of the at least one fixing groove is arranged to intersect with a radial section of the flange tube; a first sealing element, the first sealing element is fixedly arranged in the annular sealing groove; a fixing ring, the fixing ring is sleeved on the insulating tube and arranged in the fixing groove; wherein the insulating tube, the fixing ring, the first sealing element and the flange are fixedly connected through a press connection process. Through the above scheme, the connection strength and load capacity of the composite insulator can be ensured, the production efficiency is improved, the preparation cost is reduced, and the sealing performance and the torsion resistance are enhanced.

Description

Technical Field

[0001] This application relates to the field of power transmission and transformation insulation equipment technology, and in particular to a composite insulator. Background Technology

[0002] Currently, composite insulators are widely used in the field of power transmission and transformation insulation equipment. The main structure of a composite insulator typically consists of a flange made of metal and a hollow insulating tube made of composite material. The mainstream connection technologies between composite and metal materials currently include adhesive bonding and crimping.

[0003] Crimping connections primarily involve compressing metal materials to induce irreversible plastic deformation and tightly interlock the composite materials. Force is transmitted through friction and mechanical interlocking forces between the two materials. Due to the limited coefficient of friction between the composite and metal materials, a large interlocking force is required to ensure a successful connection. Therefore, this technology is generally used for connecting solid composite rods. If the material being processed is composite tubing, the large crimping force can easily damage the tubing. Without damage to the tubing, the connection effect is poor. Furthermore, since solid rods do not require sealing, existing crimping technologies lack corresponding sealing technologies, making it difficult to meet the sealing requirements of tubing. Therefore, existing composite insulators typically use adhesive bonding to connect flanges and insulating tubes. Adhesive bonding primarily involves injecting adhesive into the gap between the flange and the pipe, allowing it to solidify and form a gelled adhesive layer. This layer then connects the flange and the insulating pipe for force transmission. During processing, it's crucial to ensure the adhesive completely fills the gap and fully cures. This necessitates extensive additional machining of the flange to create injection holes, adhesive flow channels, and other structures, ensuring unobstructed adhesive flow. Furthermore, considerable time is required to heat both the pipe and the flange, allowing the adhesive in the gap to fully solidify. Therefore, adhesive bonding requires not only high-temperature resistant flanges and pipes, but also specialized adhesive injection and heating machines, and a significant amount of manual labor, resulting in a relatively high overall cost. Utility Model Content

[0004] The main technical problem addressed by this application is to provide a composite insulator that can ensure connection strength and load capacity while improving production efficiency, reducing manufacturing costs, and enhancing its sealing and torsional performance.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application is: providing a composite insulator, including an insulating tube, a flange, and a fixing ring. The outer wall of the end of the insulating tube is provided with at least one first annular groove; the flange includes a flange tube and a flange plate, the flange tube is sleeved on the end of the insulating tube, the flange plate covers at least a portion of the end face of the flange tube, the inner wall of the flange tube is provided with at least one second annular groove and at least one annular sealing groove, the second annular groove and the first annular groove are correspondingly arranged to cooperate to form a fixing groove, wherein the radial section of at least one fixing groove intersects with the radial section of the flange tube; a first sealing element is fixedly disposed in the annular sealing groove; the fixing ring is sleeved on the insulating tube and disposed in the fixing groove; wherein the insulating tube, the fixing ring, the first sealing element, and the flange are fixedly connected by a crimping process.

[0006] This application uses a crimping process to press the flange onto the end of the insulating tube. During crimping, the flange diameter decreases, and the flange undergoes irreversible plastic deformation under external pressure, tightly gripping the retaining ring, the first sealing element, and the insulating tube. Because the composite insulator of this application has a retaining ring embedded between the flange and the insulating tube, with the inner side of the retaining ring inserted into the outer wall of the insulating tube and the outer side inserted into the inner wall of the flange, the friction and mechanical gripping force between the flange and the insulating tube are increased. This allows for a higher connection strength even with relatively low crimping pressure, ensuring a stable connection between the flange and the insulating tube, while preventing the insulating tube from being damaged by excessive crimping pressure. This application also includes a first sealing element between the flange and the insulating tube. This first sealing element prevents external moisture from entering the insulating tube along the interface between the flange and the insulating tube, thus preventing corrosion. It also prevents leakage of the filling material (e.g., filling gas) inside the insulating tube. Furthermore, this application provides at least one fixing groove whose radial cross-section intersects with the radial cross-section of the flange. This ensures that the radial cross-section of the fixing ring installed in the at least one fixing groove also intersects with the radial cross-section of the flange. In other words, the fixing ring is inclined relative to the radial cross-section of the flange. When the composite insulator is subjected to torsional force, the fixing ring's torsional movement is hindered due to the restriction of the fixing groove, thereby generating anti-torsional force and improving the composite insulator's torsional resistance. This application achieves a stable connection between the hollow flange and the hollow insulating tube, reducing material costs and the weight of the composite insulator while enhancing its sealing and torsional resistance. In addition, since this application achieves a fixed connection between the flange and the insulating tube through a crimping process, it eliminates the trouble of designing and processing additional structures such as the flange injection hole and adhesive flow channel required in the adhesive bonding technology. It also eliminates the adhesive injection process, saving the labor time for injecting adhesive and waiting for the adhesive to cure, thus speeding up production efficiency. At the same time, it eliminates the need to heat-treat the pipe and flange, preventing the insulating tube from deforming due to heat and affecting product quality.

[0007] Preferably, the first annular groove and / or the second annular groove and / or the annular sealing groove are rectangular grooves.

[0008] The first and second annular grooves, with rectangular cross-sections, can mate with the fixed ring, which also has a rectangular cross-section. Furthermore, the annular sealing groove, with its rectangular cross-section, facilitates the installation of the first sealing element, ensuring sealing performance, and the rectangular groove is easy to machine. The bottom wall of the rectangular groove can withstand radial pressure, and the side walls can withstand axial pressure, ensuring connection strength.

[0009] Preferably, there are multiple first annular grooves and multiple second annular grooves, and the multiple first annular grooves and multiple second annular grooves are distributed at intervals along the axial direction of the insulating tube; the multiple first annular grooves and multiple second annular grooves are arranged in a one-to-one correspondence, and the corresponding first annular grooves and second annular grooves cooperate to form the fixing groove, and each fixing groove is fixedly provided with the fixing ring.

[0010] The above configuration can ensure the connection strength between the insulating tube and the flange, and the more annular grooves, the second annular grooves, and the more fixing rings there are, the higher the connection strength between the insulating tube and the flange.

[0011] Preferably, the radial sections of the plurality of fixing grooves are arranged in parallel.

[0012] The above settings allow all fixed grooves to be machined using the same set of machining parameters during the machining process, thereby reducing machining difficulty and improving machining efficiency.

[0013] Preferably, the plurality of fixing slots includes a first fixing slot in the middle position, and one end of the fixing slots located on both sides of the first fixing slot is arranged to converge toward the first fixing slot.

[0014] The above configuration makes the overall structure of multiple fixed slots more symmetrical, which can reduce the additional internal force generated by processing multiple fixed slots, thereby making the composite insulator more uniformly stressed and ensuring product quality.

[0015] Preferably, the radial section of the first fixing groove is parallel to the radial section of the flange pipe, and the fixing grooves located on both sides of the first fixing groove are symmetrically arranged about the first fixing groove.

[0016] The above configuration allows the overall structure of multiple fixed slots to be symmetrically arranged relative to the first fixed slot, which can avoid additional internal forces generated due to the processing of multiple fixed slots, thereby making the composite insulator 10 more uniformly stressed and further improving product quality.

[0017] Preferably, the second annular groove closest to the flange is defined as the first target groove, the second annular groove farthest from the flange is defined as the second target groove, and the second annular groove adjacent to the second target groove is defined as the third target groove. There are multiple annular sealing grooves, which are distributed at intervals along the axial direction of the insulating tube. Each annular sealing groove is fixedly provided with the first sealing element. One annular sealing groove is located between the first target groove and the flange, and another annular sealing groove is located between the second target groove and the third target groove.

[0018] Specifically, the first seal in the annular sealing groove between the second target groove and the third target groove can prevent external moisture from entering, and the first seal in the annular sealing groove between the first target groove and the flange can prevent the filling material in the insulating tube from leaking, thereby enhancing the sealing performance of the composite insulator.

[0019] Preferably, at least one of the radial sections of the fixing groove forms an inclined angle with the radial section of the flange pipe, the inclined angle being in the range of 7°-15°.

[0020] The above-mentioned angle range can avoid the fixed groove occupying too much flange space due to an excessive tilt angle, thus increasing material costs. It can also avoid the increased difficulty in installing the fixed ring caused by an excessive tilt angle, and can also avoid the insufficient torsional resistance of the fixed ring caused by an excessively small tilt angle.

[0021] Preferably, the outer wall of the flange tube is provided with a locking hole communicating with the second annular groove, and the composite insulator further includes a locking member, which is inserted into the locking hole so that the fixing ring abuts against the insulating tube.

[0022] Specifically, after crimping, the locking device applies pressure to the retaining ring, which ensures that the inner wall of the retaining ring is tightly attached to the insulating tube. On the one hand, this reduces the fitting gap between the flange and the insulating tube, as well as the width design requirements of the retaining ring, allowing the flange and retaining ring to be smaller in size while meeting assembly requirements and reducing material costs. On the other hand, it reduces the machining precision of the retaining groove, preventing the retaining ring from failing to abut against the insulating tube after crimping due to machining errors, thus affecting product quality.

[0023] Preferably, a second sealing element is provided between the end face of the insulating tube and the disc face of the flange.

[0024] The second seal can further enhance the sealing performance between the flange pipe and the insulating pipe, preventing external moisture from entering the interior of the insulating pipe and preventing leakage of the filling material in the insulating pipe.

[0025] Preferably, the fixing ring is provided with a through groove, which penetrates the fixing ring in both the radial direction and the direction parallel to the axial direction of the fixing ring. The through groove includes a first groove wall and a second groove wall arranged opposite each other in the circumferential direction of the fixing ring, wherein the included angle between the first groove wall and the second groove wall is in the range of 5°-10°; or, the fixing ring includes a plurality of independently arranged arc-shaped rings, which are arranged around the insulating tube and are all arranged in the fixing groove, and the central angle of each arc-shaped ring is less than or equal to 180°, and the sum of the central angles of the plurality of arc-shaped rings is slightly less than or equal to 360°.

[0026] The above configuration allows the retaining ring to be easily and quickly inserted into the second annular groove.

[0027] Preferably, the flange further includes a reinforcing rib disposed around the flange tube and connecting the flange tube and the flange plate. The reinforcing rib includes a first end connected to the flange tube. In the axial direction of the insulating tube, the distance between any second annular groove and any annular sealing groove and the flange plate is greater than the distance between the first end and the flange plate.

[0028] The above settings ensure that the reinforcing ribs will not be pressed by the crimping machine during the crimping process, thus preventing product damage.

[0029] The beneficial effects of this application are as follows: Unlike existing technologies, the composite insulator provided by this application can achieve high connection strength under relatively low crimping pressure, ensuring a stable connection between the flange and the insulating tube. Simultaneously, the parameters set in this application ensure that the insulating tube, flange, and retaining ring are not damaged during processing. Furthermore, the radial cross-section of at least one retaining groove intersects with the radial cross-section of the flange tube, which improves the torsional resistance of the composite insulator. In addition, the annular sealing groove and the first sealing element ensure the sealing performance between flanges, preventing external moisture from intruding into the interior of the composite insulator and preventing leakage of the internal filling material.

[0030] In addition, this application can solve the problems of low production efficiency and high production cost caused by perfect binding, and has the advantages of low cost and high efficiency. Attached Figure Description

[0031] Figure 1 This is a partial structural cross-sectional view of one embodiment of the composite insulator of this application;

[0032] Figure 2 This is a radial sectional view of one embodiment of the flange pipe of this application;

[0033] Figure 3 This is a partial axial sectional view of one embodiment of the flange pipe of this application;

[0034] Figure 4 This is a cross-sectional view of one embodiment of the flange in this application;

[0035] Figure 5 This is a cross-sectional view of another embodiment of the flange in this application;

[0036] Figure 6 This is a cross-sectional view of yet another embodiment of the flange of this application;

[0037] Figure 7 This is a cross-sectional view of another embodiment of the flange of this application;

[0038] Figure 8 This is a partial structural cross-sectional view of another embodiment of the composite insulator of this application;

[0039] Figure 9 This is a partial structural cross-sectional view of one embodiment of the insulating tube of this application;

[0040] Figure 10 This is a schematic diagram of one embodiment of the fixing ring of this application;

[0041] Figure 11 This is a cross-sectional view of one embodiment of the fixing ring of this application;

[0042] Figure 12 This is a schematic diagram of another embodiment of the fixing ring of this application;

[0043] Figure 13 This is a schematic diagram of the axial cross-section of a fixed ring according to one embodiment of this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] See Figure 1 The composite insulator 10 includes an insulating tube 11, a flange 12, a retaining ring 13, and a first sealing element 14. The insulating tube 11 is a hollow tubular structure, specifically a circular tube structure with both ends open. The insulating tube 11 is made of a composite material, specifically a glass fiber, basalt fiber, or aramid fiber impregnated with epoxy resin composite material. At least one first annular groove 111 is provided on the outer wall of the end of the insulating tube 11. Each first annular groove 111 is arranged circumferentially around the outer wall of the end of the insulating tube 11, and the depth t of the first annular groove 111 is... i The thickness is less than the wall thickness of the insulating tube 11, meaning that the first annular groove 111 does not penetrate the side wall of the insulating tube 11.

[0046] The outer periphery of the insulating tube 11 is also provided with a shed. The specific structure and size of the shed can be realized by existing technology according to the insulation requirements of the composite insulator 10, and no specific restrictions are made here.

[0047] Flange 12 includes a flange pipe 121 and a flange plate 122. The flange pipe 121 is a hollow tubular structure, specifically a circular pipe structure. One end of the flange pipe 121 is open, and the flange pipe 121 is fitted onto the end of the insulating pipe 11 through the opening. At least a portion of the end face of the other end of the flange pipe 121 is covered by the flange plate 122, which is located on the side of the flange pipe 121 away from the insulating pipe 11. The flange plate 122 and the flange pipe 121 are integrally formed to form flange 12, or the flange plate 122 and the flange pipe 121 are connected together by welding or other means to form flange 12. The material of flange 12 includes metal. The inner wall of the flange pipe 121 is provided with at least one second annular groove 123 and at least one annular sealing groove 124. The second annular groove 123 is arranged around the inner wall of the flange pipe 121 in a circumferential direction, and the depth of the second annular groove 123 is t. f The thickness of the second annular groove 123 is less than the wall thickness of the flange tube 121, meaning the second annular groove 123 does not penetrate the side wall of the flange tube 121. The opening of the second annular groove 123 faces inward, i.e., toward the first annular groove 111, and the opening of the first annular groove 111 faces outward, i.e., toward the second annular groove 123. The second annular groove 123 and the first annular groove 111 are correspondingly arranged in the axial direction of the composite insulator 10 to cooperate in forming a fixing groove (not shown). That is, the fixing groove is arranged around the circumference of the composite insulator 10 between the flange 12 and the insulating tube 11, forming an annular cavity, which is used to install the fixing ring 13. Meanwhile, the annular sealing groove 124 is arranged around the inner wall of the flange pipe 121 in a circumferential manner. The depth of the annular sealing groove 124 is less than the wall thickness of the flange pipe 121, that is, the annular sealing groove 124 does not penetrate the side wall of the flange pipe 121. The opening of the annular sealing groove 124 faces inward, that is, towards the insulating pipe 11. The first sealing element 14 is fixedly arranged in the annular sealing groove 124. The first sealing element 14 can be a sealing ring. The material of the first sealing element 14 can be a material with good sealing performance, such as silicone rubber. The cross-sectional shape of the first sealing element 14 can be circular, rectangular, etc.

[0048] A retaining ring 13 is fitted onto the insulating tube 11 and positioned within a retaining groove. The insulating tube 11, retaining ring 13, first sealing element 14, and flange 12 are fixedly connected via a crimping process. The retaining ring 13 can be made of a material with good plasticity, such as aluminum alloy, steel, or resin. The axial length of the crimped area on the flange tube 121 is defined as the crimping length H.

[0049] Continue reading Figure 1At least one fixed groove has a radial cross-section that intersects with the radial cross-section of the flange pipe 121, that is, the radial cross-section of at least one fixed groove and the radial cross-section of the flange pipe 121 form an inclined angle ζ. When there are multiple fixed grooves, each fixed groove may have a radial cross-section that intersects with the radial cross-section of the flange pipe 121, or only some of the fixed grooves (which may be one or more fixed grooves) may have a radial cross-section that intersects with the radial cross-section of the flange pipe 121.

[0050] It is understood that the radial cross-section of the fixing groove is parallel to the radial cross-section of the fixing ring 13 in the fixing groove. That is, if the radial cross-section of a fixing groove intersects with the radial cross-section of the flange pipe 121, then the radial cross-section of the fixing ring 13 in the fixing groove also intersects with the radial cross-section of the flange pipe 121, that is, the fixing ring 13 is inclined relative to the radial cross-section of the flange pipe 121; if the radial cross-section of a fixing groove is parallel to the radial cross-section of the flange pipe 121, then the radial cross-section of the fixing ring 13 in the fixing groove is also parallel to the radial cross-section of the flange pipe 121.

[0051] This application uses a crimping process to press the flange 12 onto the end of the insulating tube 11. During the crimping process, the diameter of the flange 12 decreases, and the flange 12 undergoes irreversible plastic deformation under external pressure, tightly gripping the retaining ring 13, the first sealing element 14, and the insulating tube 11. Because the composite insulator 10 of this application has a retaining ring 13 embedded between the flange 12 and the insulating tube 11, with the inner side of the retaining ring 13 inserted into the outer wall of the insulating tube 11 and the outer side of the retaining ring 13 inserted into the inner wall of the flange 12, the friction and mechanical gripping force between the flange 12 and the insulating tube 11 are increased. This allows for a higher connection strength with a lower crimping pressure, ensuring a stable connection between the flange 12 and the insulating tube 11, while preventing the insulating tube 11 from being damaged due to excessive crimping pressure. In addition, since this application achieves the fixed connection between the flange 12 and the insulating tube 11 through the crimping process, it eliminates the trouble of designing and processing additional structures such as the glue injection hole and glue flow channel on the flange 12 in the glue application technology, and eliminates the glue injection process, saving the labor time of injecting glue and waiting for the glue to cure, thus speeding up production efficiency. At the same time, there is no need to heat the insulating tube 11 and the flange 12, preventing the insulating tube 11 from being deformed by heat and affecting product quality.

[0052] Meanwhile, this application also provides a first sealing element 14 between the flange pipe 121 and the insulating pipe 11. The first sealing element 14 is located in the annular sealing groove 124, and after compression, the first sealing element 14 is tightly connected to the inner wall of the flange pipe 121 and the outer wall of the insulating pipe 11, so that the first sealing element 14 can ensure the sealing performance between the flange pipe 121 and the insulating pipe 11. Specifically, on the one hand, the first sealing element 14 can prevent external water vapor from entering the interior of the insulating pipe 11 along the interface between the flange pipe 121 and the insulating pipe 11, and prevent the insulating pipe 11 from being corroded by external water vapor. On the other hand, it can also prevent the filling material (such as filling gas) inside the insulating pipe 11 from leaking out.

[0053] In addition, this application also provides at least one fixing groove whose radial section intersects with the radial section of the flange tube 121, that is, the fixing ring 13 is inclined relative to the radial section of the flange tube 121. When the composite insulator 10 is subjected to torsional force, the fixing ring 13 is restricted by the fixing groove, and its torsional movement is hindered, thereby generating anti-torsional force, which can improve the anti-torsional ability of the composite insulator 10.

[0054] In one embodiment, the tilt angle ζ ranges from 7° to 15°, for example, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, or 15°. This angle range avoids excessive tilt angle ζ, which would cause the fixing groove to occupy too much space on the flange 12, thus increasing material costs. It also avoids increased installation difficulty of the fixing ring 13 due to an excessively large tilt angle ζ, and avoids insufficient torsional resistance of the fixing ring 13 due to an excessively small tilt angle ζ. It should be noted that this application does not limit the specific value of the tilt angle ζ, and it can be set according to actual needs.

[0055] Optionally, continue reading Figure 1 To further enhance the sealing performance between the flange 121 and the insulating pipe 11, a second sealing element 15 is provided between the end face of the insulating pipe 11 and the disc face of the flange 122. Its specific structure and materials are similar to those of the first sealing element 14, and will not be described in detail here.

[0056] In one embodiment, the second seal 15 is disposed in a first receiving groove (not shown) on the end face of the insulating tube 11. In another embodiment, the second seal 15 is disposed in a second receiving groove (not shown) on the surface of the flange 122. In yet another embodiment, the end face of the insulating tube 11 has a first receiving groove, and the surface of the flange 122 has a second receiving groove, with a portion of the second seal 15 disposed in the first receiving groove and a portion disposed in the second receiving groove. In other embodiments, the second seal 15 may not be provided.

[0057] See Figure 2 as well as Figure 3In another embodiment, the outer wall of the flange tube 121 is provided with a locking hole 16 communicating with the second annular groove 123. The composite insulator 10 also includes a locking member (not shown), which is inserted into the locking hole 16 to abut the fixing ring 13 against the insulating tube 11. Specifically, in order to ensure that the fixing ring 13 can fit tightly against the insulating tube 11 in the final product, after the crimping is completed, the locking member is inserted into the locking hole 16, and the locking member applies a compressive force to the fixing ring 13, thereby making the inner wall of the fixing ring 13 fit tightly against the insulating tube 11. It can be understood that since the fixing ring 13 can fit tightly against the insulating tube 11 under the action of the locking member, the fitting gap t between the flange 12 and the insulating tube 11 can be reduced. s and the width t of the fixing ring 13 sr The design requirement of (the difference between the outer radius and the inner radius of the retaining ring 13) allows the flange 12 and the retaining ring 13 to be smaller in size while meeting assembly requirements, thus reducing material costs. On the other hand, it can reduce the machining accuracy of the retaining groove and avoid the retaining ring 13 failing to abut against the insulating tube 11 after crimping due to machining errors, thereby affecting product quality.

[0058] In one embodiment, the locking hole 16 is a threaded hole, the locking element is a bolt, and in order to ensure the sealing of the threaded hole, the bolt can be used in conjunction with a sealing gasket.

[0059] In one embodiment, see Figure 2 as well as Figure 3 To further ensure the contact between the retaining ring 13 and the insulating tube 11, the same second annular groove 123 can simultaneously communicate with multiple locking holes 16, and these multiple locking holes 16, which communicate with the same second annular groove 123, are arranged at intervals along the circumference of the flange tube 121. After crimping, multiple locking elements can be used to simultaneously apply pressure to the retaining ring 13, ensuring that the inner wall of the retaining ring 13 is tightly attached to the insulating tube 11. In other embodiments, a second annular groove 123 may also communicate with only one locking hole 16.

[0060] See Figure 4 as well as Figure 5 In one embodiment, the flange 122 has an annular disc-shaped structure, covering part of the end face of the flange pipe 121, see reference. Figure 1 , Figure 6 as well as Figure 7 In another embodiment, the flange 122 is a circular disc structure that covers all end faces of the flange tube 121. During design, a suitable flange 122 can be selected based on the application requirements of the composite insulator 10.

[0061] See Figure 5 as well as Figure 7In one embodiment, the flange 12 further includes reinforcing ribs 125. The reinforcing ribs 125 are disposed around the flange tube 121 and connect the flange tube 121 to the flange plate 122. The inclusion of reinforcing ribs 125 ensures the overall strength of the flange 12 and improves its service life. Multiple reinforcing ribs 125 can be provided, arranged at intervals along the circumference of the flange tube 121, further enhancing the strength of the flange 12 and extending its service life.

[0062] Optionally, continue reading Figure 1 Both the first annular groove 111 and the second annular groove 123 are rectangular grooves. Optionally, their dimensions can be the same or different, as long as they can be used to secure the retaining ring 13. This application does not impose any specific limitations.

[0063] Optionally, continue reading Figure 1 The annular sealing groove 124 can also be a rectangular groove. The depth of the annular sealing groove 124 can be equal to or different from the depth of the second annular groove 123, as long as the annular sealing groove 124 can fix the first sealing element 14.

[0064] The first annular groove 111 and the second annular groove 123, both with rectangular cross-sections, can mate with the fixed ring 13, which also has a rectangular cross-section. The annular sealing groove 124, with its rectangular cross-section, facilitates the installation of the first seal 14, and the rectangular groove is easy to process. Furthermore, the bottom wall of the rectangular groove can withstand radial pressure, and the side wall of the rectangular groove can withstand axial pressure, ensuring connection strength.

[0065] Optionally, there are multiple first annular grooves 111 and multiple second annular grooves 123, which are distributed at intervals along the axial direction of the insulating tube 11. Each of the multiple first annular grooves 111 and multiple second annular grooves 123 is arranged in a one-to-one correspondence, and the corresponding first annular grooves 111 and second annular grooves 123 cooperate to form a fixing groove, in which a fixing ring 13 is fixedly installed. By fixing multiple fixing rings 13 with multiple sets of fixing grooves, the connection strength between the insulating tube 11 and the flange 12 can be guaranteed, and the more fixing grooves and fixing rings 13 there are, the better the connection strength. Specifically, the number of fixing grooves and fixing rings 13 is greater than or equal to three sets. At the same time, considering processing time, production efficiency, and production cost, the fewer the number of fixing grooves and fixing rings 13, the lower the manufacturing cost. Therefore, considering both connection strength and manufacturing cost, in this embodiment, there are three first annular grooves 111 and three second annular grooves 123. One first annular groove 111 and one second annular groove 123 form one fixing groove, so there are also three fixing grooves. There are also three fixing rings 13. In other embodiments, the number of fixing grooves and fixing rings 13 can be greater, as long as the connection requirements are met; no specific limitation is made here.

[0066] Continue reading Figure 1 In one embodiment, the radial sections of the multiple fixing grooves are arranged in parallel, that is, the radial sections of the multiple fixing rings 13 are arranged in parallel. This arrangement allows all the fixing grooves to be machined using the same set of machining parameters during the machining process, thereby reducing machining difficulty and improving machining efficiency.

[0067] See Figure 8 In another embodiment, the plurality of fixing grooves includes a first fixing groove in the middle position, and the fixing grooves on both sides of the first fixing groove are arranged with one end facing the first fixing groove. That is, in the radial direction of the insulating tube 11, one end of the plurality of fixing grooves is in a convergent state, and one end of the plurality of fixing rings 13 is in a convergent state, so that the overall structure of the plurality of fixing grooves is more symmetrical, which can reduce the additional internal force generated by processing multiple fixing grooves, thereby making the composite insulator 10 more uniformly stressed, ensuring product quality, and extending its service life.

[0068] Continue reading Figure 8 In one embodiment, the plurality of fixing grooves includes a first fixing groove, the radial section of which is parallel to the radial section of the flange pipe 121. The fixing grooves on both sides of the first fixing groove are symmetrically arranged about the first fixing groove. That is, if the fixing ring 13 in the first fixing groove is defined as the first fixing ring, then the fixing rings 13 on both sides of the first fixing ring are symmetrically arranged about the first fixing ring. This makes the overall structure of the plurality of fixing grooves symmetrical with respect to the first fixing groove, which can avoid additional internal forces generated due to the processing of multiple fixing grooves, thereby making the composite insulator 10 more uniformly stressed, further improving product quality and extending its service life.

[0069] The number of annular sealing grooves 124 can be one or more, see reference. Figure 1 In one embodiment, there are multiple annular sealing grooves 124, each containing a first sealing element 14. It is understood that the presence of multiple annular sealing grooves 124 can further enhance the sealing performance between the insulating tube 11 and the flange tube 121. Considering processing time, production efficiency, and production cost, the fewer the number of annular sealing grooves 124 and first sealing elements 14, the lower the manufacturing cost and the higher the production efficiency. Therefore, comprehensively considering sealing performance and manufacturing cost, in this embodiment, as... Figure 1 As shown, there are two annular sealing grooves 124 and two first sealing elements 14.

[0070] Continue reading Figure 1The second annular groove 123 closest to the flange 122 is defined as the first target groove, the second annular groove 123 farthest from the flange 122 is defined as the second target groove, and the second annular groove 123 adjacent to the second target groove is defined as the third target groove. There are multiple annular sealing grooves 124, which are distributed at intervals along the axial direction of the insulating tube 11. Each annular sealing groove 124 is fixedly provided with a first sealing element 14. One annular sealing groove 124 is located between the first target groove and the flange 122, and another annular sealing groove 124 is located between the second target groove and the third target groove.

[0071] Specifically, the first seal 14 located in the annular sealing groove 124 between the second and third target grooves can prevent external moisture from entering, and the first seal 14 located in the annular sealing groove 124 between the first target groove and the flange 122 can prevent leakage of the filler in the insulating tube 11. Therefore, the above arrangement can effectively block external moisture from entering the interior of the insulating tube 11 and effectively prevent leakage of the filler in the insulating tube 11, thereby enhancing the insulation performance of the composite insulator 10.

[0072] In other embodiments, an annular sealing groove 124 can be provided between any two adjacent second annular grooves 123. This application does not limit the number or specific location of the annular sealing grooves 124.

[0073] Optionally, see Figure 9 and combined Figure 1 On the insulating tube 11, a protrusion 112 is formed between two adjacent first annular grooves 111. The ratio of the depth of the first annular groove 111 to the distance between two adjacent first annular grooves 111 is greater than or equal to one-third.

[0074] When the composite insulator 10 is under load, the fixing ring 13 transmits force to the insulating tube 11 through shearing action in a direction parallel to the axial direction of the insulating tube 11. Figure 9 A simplified force diagram of the first annular groove 111 is shown, illustrating the normal stress σ acting on the sidewall of the first annular groove 111 of the insulating tube 11. a The figure also shows the shear stress τ experienced by the protrusion 112 between two adjacent first annular grooves 111. The figure further shows the depth of the first annular groove 111, i.e., the radial height t of the i-th protrusion 112 along the axial direction of the insulating tube 11. i The distance between two adjacent first annular grooves 111, i.e. the height of the i-th protrusion 112 along the axial direction of the insulating tube 11, is h. i .

[0075] Since the insulating tube 11 is made of composite material, and the shear properties of composite materials are mainly determined through standard components, the stress mode of the standard components during the test is similar to that of the composite material. Figure 9 The protrusion 112 in the model exhibits the same stress pattern. According to the testing specifications in this field, the ratio of the length of the compression surface to the length of the shear surface of the standard component is 7:20, approximately 1:3. The measured allowable shear strength of this standard component is f. v This indicates that the ratio of the height of the protrusion 112 in the radial direction of the insulating tube 11 to its height in the axial direction of the insulating tube 11 (i.e., the depth t of the first annular groove 111) is... i The distance h between the two adjacent first annular grooves 111 i (ratio)t i / h i When the depth is ≥1 / 3, the allowable shear strength of the composite material can be maximized. Furthermore, if the depth t of the first annular groove 111... i If the value is too large, it will lead to an increase in the cutting amount during the machining of the insulating tube 11, resulting in material waste. Therefore, t i / h i ≈1 / 3 is a better value.

[0076] When t i / h i Take 1 / 3, that is, each bump 112 can provide approximately f v When considering the shear strength, the maximum shear strength τ that the insulating tube 11 can provide within the crimp length H is... max For ∑h i f v / H.

[0077] Furthermore, in order to ensure that the strength of the protrusion 112 can be properly utilized, the first annular groove 111 also needs to be designed in a certain way. The height h of the first annular groove 111 along the axial direction of the insulating tube 11 is... d Its depth t along the radial direction of the insulating tube 11 i The relationship between them needs to be determined based on the yield strength of the retaining ring 13. The height h of the first annular groove 111 in the axial direction of the insulating tube 11. d Calculate h using the following formula: d =h r +Δh, where h r Let Δh be the thickness of the retaining ring 13 along the axial direction of the insulating tube 11, and let Δh be the maximum allowable machining error of the retaining ring 13. Based on force balance, the average normal stress σ of the protrusion 112... a =h i f v / t i Therefore, when the forces are in equilibrium, the average normal stress on the fixed ring 13 is also σ. a According to the von Mises criterion, the fixed ring 13 reaches the yield strength f y1 The shear stress τ that can be provided at that time y For ((f) y12 -σ a 2 ) / 3) 0.5 From the balance of local pressure and shear force of the fixed ring 13, we can obtain: h r =σ a t i / τ y The maximum permissible machining error Δh of the fixed ring 13 can be selected according to the actual machining accuracy, Δh = 0.1~0.5mm.

[0078] Optionally, see Figure 10 and Figure 11 In one embodiment, the fixing ring 13 adopts an integral design and is provided with a through groove 131. The through groove 131 penetrates the fixing ring 13 in both the radial direction and the direction parallel to the axial direction of the fixing ring 13. The through groove 131 includes a first groove wall 132 and a second groove wall 133 arranged opposite to each other in the circumferential direction of the fixing ring 13. The included angle β between the first groove wall 132 and the second groove wall 133 is in the range of 5°-10°. The above configuration provides an opening in the fixing ring 13, allowing it to contract to a certain extent. By compressing the distance between the first groove wall 132 and the second groove wall 133, the diameter of the fixing ring 13 can be reduced, enabling it to be inserted into the flange 12. When the fixing ring 13 moves into the second annular groove 123, it can open under its own elastic force. At this time, the distance between the first groove wall 132 and the second groove wall 133 increases, allowing the fixing ring 13 to be inserted into the second annular groove 123, and the insulating tube 11 can be inserted into the fixing ring 13.

[0079] The outer diameter of the fixed ring 13 in the free state is defined as D. r The inner diameter is defined as d. r When the aforementioned locking element and locking hole 16 are not provided, the width t of the retaining ring 13 is... sr It should be less than the depth t of the first annular groove 111 i The depth t of the second annular groove 123 f The sum is then subtracted by the maximum depth tolerance of the first annular groove 111 and the maximum depth tolerance of the second annular groove 123 in sequence to ensure the assembly of the insulating tube 11, flange 12, and retaining ring 13. dd represents the dimensional tolerance of the retaining ring 13. This tolerance does not need to be set too small; for example, it can be 0.1 (t). i +t f To reduce processing difficulty. Correspondingly, At this time, the included angle β between the first trench wall 132 and the second trench wall 133 must satisfy (360-β) / 360D. r≤d, to ensure that the insulating tube 11 can be inserted into the fixing ring 13, where d is the inner diameter of the flange tube 121.

[0080] In another embodiment, when the aforementioned locking element and locking hole 16 are provided, the depth of the second annular groove 123 on the flange pipe 121 should be greater than (t). sr +dd), so that when the fixing ring 13 is placed into the second annular groove 123, it will not protrude from the second annular groove 123, and at the same time, the fitting clearance t between the insulating tube 11 and the flange tube 121 is... s Then let ε be taken. e D a / 2, ε e D represents the maximum elastic strain of flange pipe 121. a The average of the outer and inner diameters of flange 121; D of the retaining ring 13. r It should be greater than (d+2t) f This design ensures that the retaining ring 13 fits snugly against the flange tube 121 during assembly, preventing it from obstructing the assembly of the insulating tube 11. Furthermore, after crimping, inserting and tightening the locking element into the locking hole 16 compresses the retaining ring 13, ensuring it fits snugly against the insulating tube 11. It is important to note that the width t of the retaining ring 13 at this point... sr ≥2t i This ensures that after the locking component is tightened, the retaining ring 13 can still be inserted into the retaining groove with the same width, and at this time β satisfies (360-β) / 360d. r ≤d-2t i .

[0081] Optionally, see Figure 11 The fixing ring 13 has rounded edges to ensure that the sharp corners of the fixing ring 13 will not scratch the insulating tube 11.

[0082] See Figure 12 In another embodiment, the fixing ring 13 includes a plurality of independently arranged arc-shaped rings 134, which are arranged around the insulating tube 11 and are all arranged in the fixing groove. The central angle of each arc-shaped ring 134 is less than or equal to 180°, and the sum of the central angles of the plurality of arc-shaped rings 134 is slightly less than or equal to 360°.

[0083] and Figure 10 The implementation methods are different, Figure 12The fixing ring 13 in the embodiment adopts a split design, with multiple arc-shaped rings 134 arranged along the circumference of the insulating tube 11 to form the fixing ring 13. At the same time, the central angle of each arc-shaped ring 134 is less than or equal to 180°. This setting can reduce the difficulty of placing the fixing ring 13 into the second annular groove 123. Specifically, multiple arc-shaped rings 134 can be placed into the fixing groove in sequence. Since the central angle θ of each arc-shaped ring 134 is less than or equal to 180°, when placing the arc-shaped ring 134, it is not necessary to radially compress the arc-shaped ring 134 to insert it into the second annular groove 123.

[0084] The number of arc-shaped rings 134 can be two, three, four or more, as long as multiple arc-shaped rings 134 can be spliced ​​together to form a fixed ring 13.

[0085] In one embodiment, the central angles of the multiple arc rings 134 are all equal, so that the same mold can be used to prepare the arc rings 134 during the preparation process, which can reduce the preparation cost.

[0086] In one embodiment, considering the existence of processing errors, in order to avoid the sum of the final central angles of multiple arc rings 134 being greater than 360° and thus unable to place all arc rings 134 into the second annular groove 123, the central angle of each arc ring 134 is set to be less than or equal to the ratio of 360° to the number of arc rings 134 minus the angle processing error.

[0087] Optionally, the depth t of the second annular groove 123 f The depth t of the first annular groove 111 is greater than or equal to the depth t i , i.e. t f ≥t i This ensures that the fixed ring 13 can provide the previously calculated shear strength when it yields.

[0088] Optionally, continue reading Figure 1 The axial crimping length H between the insulating tube 11 and the flange tube 121 is greater than or equal to a length threshold, wherein the length threshold is derived based on the maximum shear strength that the insulating tube 11 can provide and the maximum load that the insulating tube 11 can withstand.

[0089] Specifically, the crimping length H needs to be determined based on the external force and the average shear stress τ in the crimping area. Common loads on the insulating tube 11 include internal pressure, lateral bending moment, and compression. Among these, the force transmission path for compression loads is relatively smooth, directly transmitting force from the end of the insulating tube 11 to the flange 122, generally requiring no high-strength connection structure. Internal pressure loads can generally be equivalent to pull-out force and circumferential tension. The circumferential tension has a relatively small impact on the connection structure; the pull-out force is the primary influence. Therefore, the load borne by the composite insulator 10 generally includes the equivalent pull-out force F and the lateral bending moment M. The equivalent pull-out force F = pπD f 2 / 4, where D f Let T be the outer diameter of insulating tube 11, p be the internal pressure of insulating tube 11, and T be the outer diameter of insulating tube 11. s This refers to the total width of the annular sealing groove 124 within the crimping area, which is the sum of the widths of multiple annular sealing grooves 124 along the axial direction of the flange pipe 121 within the crimping area. The corresponding length threshold for the equivalent pull-out force F is F / (πD). f τ max )+T s Ignoring the force generated by the compression between the insulating tube 11 and the flange 12, i.e., assuming that the lateral bending moment M is completely offset by the shear stress, the lateral bending moment M can be obtained by the following formula: M=4*∫0 0.5π τ max H(D / 2)sinα*sinα(D / 2)dα=π(D 2 / 4)τ max H, therefore, when the lateral bending moment is M, the length threshold is 4M / (τ max πD 2 )+T s Where D is the outer diameter of flange pipe 121. Therefore, when the lateral bending moment M and the equivalent pull-out force F occur in combination, the crimping length H needs to simultaneously meet the length threshold required by both the lateral bending moment M and the equivalent pull-out force F. Therefore, the crimping length H ≥ 4M / (τ max πD 2 )+F / (πD f τ max )+T s This allows the composite insulator 10 to withstand the maximum load and the maximum shear strength at this crimp length H.

[0090] For composite insulator 10 with torque T requirements (i.e., when the load borne by composite insulator 10 also includes torque T), H corresponds to T. max Not less than T, T max The maximum torsional strength that the fixed ring 13 can provide. Since it is rare for equivalent pull-out force F, lateral bending moment M, and torque T to occur simultaneously in general structures, the torque T can be checked separately without combining multiple external forces.

[0091] The maximum torsional strength T max It is mainly related to the tilt angle ζ and the number of fixing grooves N. Assuming that the friction coefficients between the fixing ring 13 and the flange 12, between the fixing ring 13 and the insulating tube 11, and between the flange 12 and the insulating tube 11 can be ignored, the shear force per unit length generated by the torque T at a single fixing ring 13 is T / N / (πD) in the horizontal direction. f Due to the existence of the tilt angle ζ and the assumption of no friction in the surrounding area, the shear force per unit length in the horizontal direction needs to form a force T / N / (πD) per unit length perpendicular to the axial direction of the fixed ring 13 and at an angle ζ to the axial direction of the insulating tube 11. f Due to the antisymmetry of torsion and the positive symmetry of the structure, the vertical shear force generates a resultant force with a vertical component of zero across the entire structure. The torque generated by the vertical shear force and the reaction torque generated by the contact force between the insulating pipe 11 and the flange 12 cancel each other out. Considering the stress situation on the free surface, this application assumes that the compressive stress σ on the cross section of the fixing ring 13 is... r With shear force τ r The distribution is as follows Figure 13 As shown, the cross-section refers to the axial cross-section of the fixed ring 13, that is, the cross-section parallel to the axial direction of the fixed ring 13, and the compressive stress σ r The shear force τ acts on the radial section of the fixed ring 13, with its direction perpendicular to the radial section of the fixed ring 13. r The stress acts on the radial section of the fixed ring 13, extending circumferentially along the fixed ring 13. The maximum compressive stress σ rmax =T / N / (πD) f ) / sinζ / t min , where t min Let t be the smaller of the contact width between the fixed ring 13 and the first annular groove 111 along the radial direction of the fixed ring 13, and the contact width between the fixed ring 13 and the second annular groove 123 on the flange pipe 121 along the radial direction of the fixed ring 13. If machining errors are not considered, then t min The depth t of the first annular groove 111 i The depth t of the second annular groove 123 f The minimum value in the range. Since the stress mode of the fixed ring 13 is similar to that of the bolt thread, it can be considered that the fixed ring 13 is subjected to stress in a cantilever beam-like manner, and the maximum shear stress is τ. rmax =1.5T / N / (πD) f ) / sinζ / h r Compressive stress σ r The slope of the change along the axial direction of the fixed ring 13 should be related to τ. r / t min Consistent, by Figure 13It can be seen that the compressive stress on the radial section where the centerline of the fixed ring 13 is located does not exceed σ. rmax / 2, where the centerline refers to the annular line containing the centers of each cross-section of the fixed ring 13. Therefore, the von Mises equivalent stress on the radial section containing the centerline of the fixed ring 13 when the fixed ring 13 is nearing failure can be roughly estimated as (σ rmax 2 / 4+3τ rmax 2 ) 0.5 The von Mises equivalent stress on the axial end face of the fixed ring 13 is σ. rmax Therefore, the T that the fixed ring 13 can provide is... max =min[f y1 N*(πD f )*sinζ*t min ,f y1 N*(πD f )*sinζ / (1 / 4 / t min 2 +6.75 / h r 2 ) 0.5 ].

[0092] Optionally, the product of the yield strength of flange 121 and twice the wall thickness of flange 121 is defined as the first product; the product of the circumferential compressive yield strength of insulating tube 11 and twice the wall thickness of insulating tube 11 is defined as the second product; the ratio of the sum of the first product and the second product to the outer diameter of flange 121 after crimping is defined as the first ratio; wherein the pressure required for the crimping process, i.e., the crimping pressure P, is less than or equal to the first ratio.

[0093] Specifically, see Figure 1 Under the action of the crimping force, the flange pipe 121 undergoes plastic deformation inward, and its diameter decreases. Therefore, the crimping pressure P needs to ensure that the deformation of the flange 12 is sufficient to fill the fitting gap t between the flange 12 and the insulating pipe 11. s This will not cause damage to the insulating tube 11 and flange 12. Since flange tube 121 and flange plate 122 are often connected together by welding or casting, a connection seam is formed at the connection between flange tube 121 and flange plate 122. That is, a weld seam is formed by welding and a casting seam is formed by casting. The second annular groove 123 and annular sealing groove 124 should be spaced apart from the connection seam. In other words, the crimping length H should be less than or equal to the total length of flange tube 121 minus the width of the connection seam, so as to ensure that the connection seam between flange tube 121 and flange plate 122 will not be crushed by the crimping machine during the crimping process, thus preventing product damage.

[0094] In another embodiment, see Figure 5 as well as Figure 7 When the flange 12 also includes a reinforcing rib 125, the end of the reinforcing rib 125 connected to the flange tube 121 is defined as the first end, that is, the end of the reinforcing rib 125 away from the flange 122 is the first end. At this time, in the axial direction of the insulating tube 11, the distance between any second annular groove 123 and any annular sealing groove 124 and the flange 122 is greater than the distance between the first end and the flange 122. In other words, any second annular groove 123 and any annular sealing groove 124 are spaced apart from the first end of the reinforcing rib 125, so that the crimping length H is less than or equal to the total length of the flange tube 121 minus the length of the reinforcing rib 125 in the axial direction of the insulating tube 11, so as to ensure that the reinforcing rib 125 will not be crushed by the crimping machine during the crimping process, thus causing product damage.

[0095] The crimping pressure P needs to ensure that the flange pipe 121 yields while the insulating pipe 11 is not damaged. Therefore, the minimum value of the crimping pressure P is P_min. min =f y (Dd) / D, where f y Let be the yield strength of flange 121, D be the outer diameter of flange 121, and d be the inner diameter of flange 121. The maximum value of the crimping pressure P is P0. max =(f y *(Dd)+f uf *(D f -d f )) / (D-2t s ), f uf The circumferential compressive yield strength of the insulating tube 11 can generally be estimated based on 0.8 times the measured circumferential compressive strength, according to technical experience in this field. f d f These are the outer and inner diameters of the insulating tube 11, respectively, t s To accommodate the clearance, it is equal to 0.5*(dD) f The first product is f. y *(Dd), where (Dd) is twice the wall thickness of flange pipe 121, and the second product is f. uf *(D f -d f ), (D f -d f (D-2t) is twice the wall thickness of insulating tube 11. s The outer diameter of the flange pipe 121 after crimping is denoted as ). The actual crimping pressure P can be taken as [P...]. min ,P max For intervals, it's best to use P. max To ensure airtightness.

[0096] Furthermore, when flange 122 covers the entire end face of flange pipe 121, the pressure loss due to the high rigidity of flange 122 needs to be appropriately considered. The aforementioned value range can be optimized, that is, the range of the aforementioned pressure P can be changed from [P...] min ,P max Replace ] with [P min +f z *(Dd) / 2 / H,P max +f z [*(Dd) / 2 / H], where f z The shear strength that the material of flange 12 can provide can be based on the shear yield strength f of the elasto-plastic material under pure shear conditions. z =f y / 1.732 estimate.

[0097] In other words, when flange 122 covers part of the end face of flange pipe 121, the crimping pressure P can be taken as [P]. min ,P max Within the specified range, when flange 122 covers the entire end face of flange pipe 121, the crimping pressure P can be taken as [P]. min +f z *(Dd) / 2 / H,P max +f z The range is *(Dd) / 2 / H]. Of course, in other embodiments, even if the flange 122 covers the entire end face of the flange pipe 121, the crimping pressure P can be taken within [P]. min ,P max ] interval.

[0098] Optionally, before crimping, the mating clearance t on one side of the insulating tube 11 and the flange tube 121 is... s The depth t of the first annular groove 111 is equal to i The larger of half of the radial elastic deformation of flange 121.

[0099] For details, please refer to [link / reference]. Figure 1 Under normal circumstances, the fit clearance t s The displacement needs to be greater than the elastic displacement generated before the flange pipe 121 undergoes plastic deformation, in order to preserve the crimping effect to the maximum extent, while also matching the gap t. s If the clearance is too large, it will lead to material waste, and because the plastic deformation of the metal flange pipe 121 is limited, an excessively large fitting clearance t will also result in material waste. s This can easily lead to damage to flange pipe 121. (Due to the fit clearance t) sUnder the initial non-zero crimping condition, the inner surface of flange 121 is a free surface, unloaded, while the outer surface bears the crimping pressure P. This indicates that the radial stress of flange 121 is between 0 and P, and the radial thickness (Dd) / 2 is relatively small compared to the diameter D. The radial deformation in the elastic stage is proportional to the thickness and the radial stress. The stress in the circumferential direction perpendicular to the radial direction on flange 121, i.e., the circumferential stress, is P*D / (Dd), and the circumferential circumference is πD. a D a = (D+d) / 2, D a Let f be the average of the outer and inner diameters of flange 121. Clearly, the circumferential stress of flange 121 is significantly greater than the radial stress, and the circumferential circumference is also significantly greater than the radial thickness. Therefore, the radial deformation of flange 121 can be ignored. The elastic limit of the metallic material is f. y When the stress is less than f y When flange pipe 121 only undergoes elastic deformation, the corresponding maximum elastic strain ε e f y / E, where E is the elastic modulus of the metallic material. Ignoring radial stress, the circumferential deformation corresponding to the elastic deformation is δ. E =ε e πD a The corresponding radial deformation is δ Ec =ε e D a Therefore, the unilateral fitting clearance t s It should be no less than ε e D a / 2, correspondingly, the condition for the metallic material not to be damaged is t s <ε d D a / 2, ε d ε is the total strain that occurs when the metal fails. d Generally significantly greater than ε e Taking aluminum alloy as an example, its ε e The failure strain is approximately 0.3%, while the total strain at failure is greater than 2.3%, approximately 7.7ε. e Q355 steel is even more extreme, with its ε... e The failure strain is 0.17%, and the failure strain is 20.2%, approximately 10¹ε. e Therefore t s Less than ε d D a The constraint / 2 is too broad and has almost no limiting effect. Therefore, from the perspective of saving materials, a one-sided fit clearance t is set. s The maximum height h of the retaining ring 13 protruding from the inner wall of the flange tube 121 when in the unpressurized state. max Or ε e D aThe larger value in / 2 is acceptable, where h max =t sr -t i +δ0, where δ0 is the fit tolerance, which can be taken as 0.1 to 0.5 mm according to technical experience in this field.

[0100] Optionally, in some embodiments, the insulating tube 11 is filled with a filler, such as an insulating gas, specifically sulfur hexafluoride gas, nitrogen or air, to ensure the insulation performance of the composite insulator 10.

[0101] For flange 12, its internal pressure deformation stiffness K f =d(D+d) / 2 / E / (Dd), for insulating tube 11, its internal pressure deformation stiffness K p =d f (D f +d f ) / 2 / E f / (D f -d f E f Let be the circumferential elastic modulus of the insulating tube 11, where the internal pressure deformation stiffness is defined as the amount of radial deformation of the structure when a unit pressure is increased.

[0102] The internal pressure p of the insulating tube 11 is a relative pressure, with atmospheric pressure as its reference pressure. When p > 0, meaning there is filler inside the insulating tube 11, some of the filler will seep into the gap between the flange 12 and the insulating tube 11. Due to the obstruction of the first seal 14, which is closest to the flange 122, the filler can only disperse within a limited area between the insulating tube 11 and the flange 12, defined as the dispersion area. The height h of this dispersion area along the axial direction of the insulating tube 11 is... g Let K be the distance between the face of flange 122 and its nearest first seal 14. Within the diffuse region, the internal and external pressures of insulating tube 11 are balanced, equivalent to being unaffected by expansion or contraction forces. However, flange 12 is subjected to unbalanced pressure at this location, resulting in expansion or contraction forces. Correspondingly, the average deformation of flange 12 is K. f *p*h g / H; Outside the diffused region, the insulating tube 11 is subjected to unbalanced pressure, while the internal and external pressures of the flange 12 are balanced. Correspondingly, the average deformation of the insulating tube 11 is K. p p*(Hh g When the product is subjected to internal pressure, if the average deformation of flange 12 is greater than that of insulating tube 11, it is easy for the first sealing element 14 to detach from the inner wall of insulating tube 11, causing sealing failure. Therefore, the design must meet K. p p*(Hh g ) / H≥K f *p*h g / H; When the product is subjected to external pressure, if the average deformation of flange 12 is greater than that of insulating tube 11, the first seal 14 will be squeezed tighter, resulting in a better sealing effect. Therefore, the design must meet K. p p*(Hh g ) / H <K f *p*h g / H. Furthermore, when the second seal 15 is installed, h g =0, the above design inequality always holds, and there is no need to verify the internal pressure deformation stiffness.

[0103] In one embodiment, multiple annular sealing grooves 124 are evenly spaced within the crimping area of ​​the flange 12, which avoids weakening the strength of the flange 12 due to the concentrated arrangement of multiple annular sealing grooves 124. Assuming the number of annular sealing grooves 124 is Q, taking the position closest to the flange 122 as the starting point, the distance between the centerline of the i-th annular sealing groove 124 and the edge of the crimping area away from the flange 122 is iH / (Q+1), where i = 1, 2, ..., Q. The centerline refers to the annular line at the center of the annular sealing groove 124 along the axial direction of the flange pipe 121.

[0104] The depth of the annular sealing groove 124 along the radial direction of the flange pipe 121 is defined as the depth of the annular sealing groove 124, and the depth of the annular sealing groove 124 before crimping is denoted as t. m The depth of the annular sealing groove 124 after crimping is denoted as t. m1 It is understandable that t m1 With t m Related, in setting t m At this time, it is necessary to ensure that the depth t of the annular sealing groove 124 after crimping is [missing information]. m1 Satisfy: t m1 =ηD s In this embodiment, the first sealing element 14 is a sealing ring with a circular cross-section, D s η is the wire diameter of the first seal 14, i.e., the diameter of the circular cross-section of the first seal 14; η = 1 - S, where S is the design compression ratio of the first seal 14. According to the technical specifications in this field, S is generally 16% to 25%, meaning that the design compression ratio can meet the requirements within this range. This is mainly because, on the one hand, the machining accuracy of the first seal 14 can generally only be achieved at the 0.1 mm level, and the wire diameter of the first seal 14 is generally also at the mm level. Therefore, an excessively precise design compression ratio is difficult to achieve with the current machining level. On the other hand, an excessively high design compression ratio will lead to a short lifespan for the first seal 14, while an excessively low design compression ratio will lead to a poor sealing effect for the first seal 14.

[0105] The width b of the annular sealing groove 124 along the axial direction of the flange pipe 121 should satisfy: π(D f +tm1 )*b*t m1 =(1+p) s )πD s0 (πD s 2 ) / 4, where p s The swelling rate of the material of the first seal 14 is typically 30%, D. s0 The diameter is the centerline of the first sealing element 14, which refers to the annular line containing the centers of all cross-sections of the sealing ring. The specifications of the first sealing element 14 can be selected according to national standards and in conjunction with the dimensions of the flange 12, thus determining D. s D s0 , and thus determine t m1 t m b.

[0106] In estimating t m1 At this point, an approximate assumption needs to be introduced: the effect of plastic deformation on the material volume is negligible. This assumption is based on the fact that the effect of plastic deformation on the material density is negligible, so it can be approximated that plastic deformation does not affect the volume when the weight remains unchanged.

[0107] When the fit clearance t on one side s The maximum height h of the retaining ring 13 protruding from the inner wall of the flange tube 121 when in the unpressurized state. max At that time, the residual strain in the circumferential direction of flange 12 was 2h. max / D a +ε rf -ε lf -2f y / E; When the fit clearance t on one side s Using ε e D a At / 2, the residual strain in the circumferential direction of flange 12 is ε. rf -ε lf -f y / E, where ε rf ε represents the circumferential strain of the insulating tube 11 during crimping. rf =σ uf / E f , σ uf Given the circumferential stress of the insulating tube 11, and ignoring the wall thickness variations of the insulating tube 11 and flange tube 121, the circumferential stress σ of the insulating tube 11 is... uf =(P*(D) f +Dd)-f y *(Dd)) / (D f -d f ), ε lf ε represents the circumferential strain along the centerline of the wall of the insulating tube 11 that is ultimately retained. lf =(εrf -f y / E) / (1+E f t p / (Et a )), t p t is the wall thickness of the insulating tube. a For the wall thickness of flange pipe 121, due to ε lf Since it is elastic strain, the residual circumferential plastic strain of flange 12 is ε. rf -f y Since the volume remains constant, the radial plastic strain of / E should be -ε. rf +f y / E, then the change (increase) in the depth of the corresponding annular sealing groove 124 is (ε) rf -f y / E)t m In general, the relaxation of metallic materials will not cause the elastic strain to be converted into plastic strain to be excessively high. Therefore, the circumferential elastic deformation of flange 12 is -ε lf The corresponding radial elastic strain is vε lf Where v is the Poisson's ratio of the metal material of flange 12, typically 0.3 to 0.33, and here it refers to compressive strain. Therefore, the reduction in depth of the annular sealing groove 124 due to elastic deformation is vε. lf t m Therefore, t m1 =t m +(ε rf -f y / E)t m -vε lf t m .

[0108] This application also provides a method for preparing a composite insulator 10, the method comprising:

[0109] S110: Prepare an insulating tube 11 and a flange 12 respectively, wherein the outer wall of the end of the insulating tube 11 is provided with at least one first annular groove 111, the flange 12 includes a flange tube 121 and a flange plate 122, the flange plate 122 covers at least a portion of the end face of the flange tube 121, and the inner wall of the flange tube 121 is provided with at least one second annular groove 123 and at least one annular sealing groove 124.

[0110] In this step, the insulating tube 11 and flange 12 are formed respectively. Specifically, after forming the body structure of the insulating tube 11 and flange 12, the outer wall of the insulating tube 11 and the inner wall of the flange tube 121 are ground to remove burrs and ensure the connection effect. Then, the insulating tube 11 and flange 12 are cut according to the aforementioned design dimensions to form a first annular groove 111 on the insulating tube 11, a second annular groove 123 and an annular sealing groove 124 on the flange tube 121. At least one fixing groove has a radial cross-section that intersects with the radial cross-section of the flange tube 121. Therefore, during processing, the corresponding first annular groove 111 and second annular groove 124 need to be machined according to the aforementioned inclined angle ζ.

[0111] Furthermore, an umbrella skirt is prepared on the outer periphery of the insulating tube 11.

[0112] S120: Place the first sealing element 14 into the annular sealing groove 124 and the fixing ring 13 into the second annular groove 123.

[0113] Before this step, a fixing ring 13 is prepared. When the fixing ring 13 is a one-piece structure, the opening structure and dimensions of the fixing ring 13 are as described above; when the fixing ring 13 is a split structure, the central angles and dimensions of its multiple arc-shaped rings 134 are also as described above. Further, rounded corners are machined on the edges of the fixing ring 13.

[0114] In this step, when inserting the first sealing element 14, the first sealing element 14 can be compressed first, for example, by radial compression or direct folding, so that the first sealing element 14 can be inserted into the flange tube 121. Then, the first sealing element 14 is moved along the inner wall of the flange tube 121. When the first sealing element 14 moves to the corresponding annular sealing groove 124, the first sealing element 14 is reset by its own elasticity, so that the outer side of the first sealing element 14 is installed in the annular sealing groove 124.

[0115] When the fixing ring 13 is an integral structure, when inserting the fixing ring 13, the fixing ring 13 can be compressed radially first so that the fixing ring 13 can be inserted into the flange pipe 121. Then, the fixing ring 13 is moved along the inner wall of the flange pipe 121. When the fixing ring 13 moves to the corresponding second annular groove 123, the fixing ring 13 is reset radially by its own elasticity, so that the outer side of the fixing ring 13 is stuck into the second annular groove 123.

[0116] When the fixing ring 13 is a split structure, multiple arc-shaped rings 134 are sequentially placed into the corresponding second annular grooves 123 when the fixing ring 13 is inserted. This application does not restrict the order in which the first sealing element 14 and the fixing ring 13 are inserted; either the first sealing element 14 or the fixing ring 13 can be inserted first. In one embodiment, the first sealing element 14 and the fixing ring 13 can be inserted sequentially according to their distance from the flange 122, i.e., the closer the installation position is to the flange 122, the earlier it is inserted. S130: The insulating tube 11 is inserted into the flange tube 121, so that the fixing ring 13 is located in the fixing groove formed by the cooperation of the first annular groove 111 and the second annular groove 123, forming an insulator prefabricated component.

[0117] In this step, the insulating tube 11 is simultaneously inserted into the retaining ring 13, aligning the inner side of the retaining ring 13 with the corresponding first annular groove 111, thereby limiting the retaining ring 13 within the retaining groove. At this point, the insulating tube 11 and flange 12 in the pre-fabricated insulator are not yet pressed together, and the fitting gap t between the insulating tube 11 and flange tube 121 is... s As mentioned above.

[0118] Furthermore, prior to this step, step S131 is included: installing the second seal 15. After step S130 is performed, the second seal 15 can be located between the end face of the insulating tube 11 and the surface of the flange 122. Specifically, the second seal 15 is placed in the first receiving groove on the end face of the insulating tube 11; or the second seal 15 is placed in the second receiving groove on the surface of the flange 122, depending on the installation structure of the second seal 15.

[0119] S140: The prefabricated insulator is crimped to fix the flange 12, the retaining ring 13, the first sealing element 14, and the insulating tube 11 together to form a composite insulator 10.

[0120] Specifically, the prefabricated insulator is loaded into a crimping machine, and a crimping pressure P within the aforementioned range is applied to the crimping area on the flange 12 for crimping. The crimping length H is calculated according to the aforementioned formula. At this time, the flange 12 undergoes plastic deformation in the radial direction, its diameter decreases, and it tightly engages the fixing ring 13, the first sealing element 14, and the insulating tube 11. The first sealing element 14 is tightly connected to the inner wall of the flange tube 121 and the outer wall of the insulating tube 11, thereby crimping the flange 12, the insulating tube 11, the first sealing element 14, and the fixing ring 13 together.

[0121] Further, see Figure 2 as well as Figure 3 The process includes the following steps after step S140:

[0122] S150: Insert the locking element into the locking hole 16 so that the retaining ring 13 abuts against the insulating tube 11.

[0123] Specifically, after the locking member is inserted, the locking member applies a squeezing force to the fixing ring 13, thereby making the inner wall of the fixing ring 13 fit tightly against the bottom wall of the first annular groove 111 on the insulating tube 11, ensuring the connection between the two.

[0124] After step S140 or step S150, insulating gas or other fillers may be filled into the insulating tube 11 according to the aforementioned design pressure.

[0125] The above method enables the crimping of flange 12 and insulating tube 11, ensuring the connection strength and load capacity of the composite insulator while improving production efficiency, reducing manufacturing costs, and enhancing its sealing and torsional performance.

[0126] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A composite insulator, characterized in that, The composite insulator includes: An insulating tube, wherein at least one first annular groove is provided on the outer wall of the end of the insulating tube; A flange, comprising a flange tube and a flange plate, wherein the flange tube is sleeved on the end of the insulating tube, and the flange plate covers at least a portion of the end face of the flange tube; the inner wall of the flange tube is provided with at least one second annular groove and at least one annular sealing groove, wherein the second annular groove is correspondingly provided with the first annular groove to cooperate in forming a fixing groove, wherein the radial section of at least one of the fixing grooves intersects with the radial section of the flange tube. The first sealing element is fixedly disposed in the annular sealing groove; A fixing ring is sleeved on the insulating tube and disposed in the fixing groove; wherein the insulating tube, the fixing ring, the first sealing element, and the flange are fixedly connected by a pressing process.

2. The composite insulator according to claim 1, characterized in that, The first annular groove and / or the second annular groove and / or the annular sealing groove are rectangular grooves.

3. The composite insulator according to claim 1, characterized in that, There are multiple first annular grooves and multiple second annular grooves, and the multiple first annular grooves and multiple second annular grooves are distributed at intervals along the axial direction of the insulating tube; Multiple first annular grooves are provided in a one-to-one correspondence with multiple second annular grooves, and the corresponding first annular grooves and second annular grooves cooperate to form the fixing grooves, and each fixing groove is fixedly provided with a fixing ring.

4. The composite insulator according to claim 3, characterized in that, The radial sections of the plurality of fixed grooves are arranged in parallel.

5. The composite insulator according to claim 3, characterized in that, The plurality of fixing slots includes a first fixing slot in the middle position, and one end of the fixing slots located on both sides of the first fixing slot is arranged to converge toward the first fixing slot.

6. The composite insulator according to claim 5, characterized in that, The radial section of the first fixing groove is parallel to the radial section of the flange pipe, and the fixing grooves on both sides of the first fixing groove are symmetrically arranged about the first fixing groove.

7. The composite insulator according to claim 3, characterized in that, The second annular groove closest to the flange is defined as the first target groove, the second annular groove farthest from the flange is defined as the second target groove, and the second annular groove adjacent to the second target groove is defined as the third target groove. There are multiple annular sealing grooves, which are distributed at intervals along the axial direction of the insulating tube. The first sealing element is fixedly installed in each annular sealing groove. One annular sealing groove is located between the first target groove and the flange, and another annular sealing groove is located between the second target groove and the third target groove.

8. The composite insulator according to claim 1, characterized in that, At least one of the radial sections of the fixed groove forms an inclined angle with the radial section of the flange pipe, the inclined angle being in the range of 7°-15°.

9. The composite insulator according to claim 1, characterized in that, The outer wall of the flange tube is provided with a locking hole that communicates with the second annular groove. The composite insulator also includes a locking member, which is inserted into the locking hole so that the fixing ring abuts against the insulating tube.

10. The composite insulator according to claim 1, characterized in that, A second sealing element is provided between the end face of the insulating tube and the plate face of the flange.

11. The composite insulator according to claim 1, characterized in that, The fixing ring is provided with a through groove, which penetrates the fixing ring in both the radial direction and the direction parallel to the axial direction of the fixing ring. The through groove includes a first groove wall and a second groove wall arranged opposite to each other in the circumferential direction of the fixing ring, wherein the included angle between the first groove wall and the second groove wall is in the range of 5°-10°. Alternatively, the fixing ring may include a plurality of independently arranged arc-shaped rings, which are arranged around the insulating tube and are all disposed in the fixing groove. The central angle of each arc-shaped ring is less than or equal to 180°, and the sum of the central angles of the plurality of arc-shaped rings is slightly less than or equal to 360°.

12. The composite insulator according to claim 1, characterized in that, The flange also includes: A reinforcing rib is provided on the periphery of the flange tube and connects the flange tube to the flange plate. The reinforcing rib includes a first end connected to the flange tube. In the axial direction of the insulating tube, the distance between any second annular groove and any annular sealing groove and the flange plate is greater than the distance between the first end and the flange plate.

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