Composite insulator and manufacturing method for composite insulator

Abstract

Disclosed in the present application is a composite insulator, comprising a core rod, a sheath covering the periphery of the core rod, and a metal fitting fixedly sleeved on an end of the core rod, wherein the end of the metal fitting close to the core rod is provided with a first cavity and a second cavity, which are connected to each other; the diameter of the second cavity is greater than that of the first cavity; the end of the core rod is fixed in the first cavity, and abuts against the bottom wall of the first cavity; the second cavity is integrally provided with a sealing ring, which abuts against the bottom wall of the second cavity; the end face of the metal fitting that is close to the sheath has a curved surface; the remaining part in the second cavity is filled with a sealing adhesive; and the sealing adhesive covers the curved surface and is connected to the sheath, such that the metal fitting is connected to the sheath in a sealed manner. For the composite insulator using the above end sealing structure, the sealing performance of the connection interface between the sheath and the metal fitting can be effectively improved. Further disclosed in the present application is a manufacturing method for a composite insulator.

Description

A composite insulator and a method for manufacturing the composite insulator Technical Field

[0001] This application relates to the field of insulator technology, and in particular to a composite insulator and a method for manufacturing the composite insulator. Background Technology

[0002] Composite insulators are a crucial component of high-voltage transmission lines, bearing both electrical and mechanical properties. During operation, the sealing at the ends of composite insulators directly impacts the safety of the core rod, consequently affecting the operational stability and service life of the composite insulator. Under prolonged harsh operating conditions, if the sealing structure is poorly designed, the interfacial adhesion between the high-temperature vulcanized silicone rubber and the end fittings will decrease. This allows moisture to easily enter the sealing surface, corroding the internal structure of the end fittings or the core rod, ultimately leading to flashover and other electrical safety accidents. Summary of the Invention

[0003] To address the shortcomings of existing technologies, one of the objectives of this application is to provide a composite insulator with excellent structural design, good sealing performance, increased service life and operational stability, and reduced accident rate.

[0004] To achieve the above objectives, the technical means adopted in this application are as follows: A composite insulator includes a core rod, a sheath covering the outer periphery of the core rod, and a fitting fixedly sleeved on the end of the core rod. The fitting has a first cavity and a second cavity connected to each other near the end of the core rod. The diameter of the second cavity is larger than the diameter of the first cavity. The end of the core rod is fixed in the first cavity and abuts against the bottom wall of the first cavity. A sealing ring is provided in the second cavity and abuts against the bottom wall of the second cavity. The end face of the fitting near the sheath is curved. The remaining part of the second cavity is filled with sealant. The sealant covers the curved surface and connects with the sheath, so that the fitting and the sheath are sealed together.

[0005] The sealing ring tightly abuts against the side wall of the sheath and the second cavity, forming an interference fit, which produces appropriate elastic deformation. The sealing ring serves to seal the interface between the mandrel and the fitting, preventing external moisture from entering and causing corrosion and brittle fracture of the mandrel.

[0006] The sealant is room temperature vulcanizing silicone rubber, which has a simple sealing process and good sealing performance.

[0007] The sheath fits tightly against the bottom wall of the second cavity, providing a certain degree of sealing at the connection between the mandrel, fittings, and sheath.

[0008] Among them, at least one first sealing groove is provided around the end face of the fitting near the sheath to form a curved surface.

[0009] The first sealing groove has a rectangular cross-section, which facilitates processing.

[0010] The second cavity has a concave-convex sealing interface on its sidewall, which can increase the contact area between the sealing ring and the sidewall of the second cavity, increase the friction, reduce the risk of the sealing ring moving, and further extend the sealing path to prevent external moisture from entering and enhance the sealing effect.

[0011] The second cavity has a second sealing groove on its side wall. The second sealing groove engages with the sealing ring, which can effectively prevent the sealing ring from shifting, extend the sealing path, prevent external moisture from entering, and enhance the sealing effect.

[0012] The fitting features a raised section along the edge of its end face near the sheath, with the raised section ending in a rounded surface to form a curved surface. This rounded surface effectively reduces the sharp structural area of ​​the fitting and optimizes the electric field. Sealant covers the curved surface and connects it to the sheath, further increasing the contact area and improving sealing performance.

[0013] The fitting features a smooth connection between its end face near the sheath and its outer peripheral surface. This reduces the number of sharp structural parts on the fitting and effectively optimizes the electric field.

[0014] The second objective of this application is to provide a method for manufacturing a composite insulator, specifically including the following steps: S11: Injecting a high-temperature vulcanized silicone rubber molding sheath into the outer periphery of the middle part of the core rod to obtain a first insulator preform; S12: Pressing fittings onto both ends of the core rod to obtain a second insulator preform; S13: Sealing the target area where the core rod, sheath, and fittings contact to obtain a composite insulator.

[0015] The beneficial effects of this application are as follows: Unlike the prior art, the composite insulator of this application forms a multi-layer sealing structure at the interface between the sheath and the fitting by using sealant, sealing ring and curved surface, which can prevent external moisture from entering and causing corrosion and brittle fracture of the core rod, and reduce the risk of sealing failure.

[0016] Meanwhile, by providing a concave-convex sealing interface or a second sealing groove on the side wall of the second cavity of the fitting, this application can further extend the sealing path, prevent external moisture from entering, and enhance the sealing effect; and can further limit the position of the sealing ring, prevent the sealing ring from shifting, and make the sealing effect more stable.

[0017] Furthermore, the manufacturing method of the composite insulator in this application is simple to operate and has high production efficiency, which can ensure the sealing performance of the manufactured composite insulator. Attached Figure Description

[0018] Figure 1 is a partial structural schematic diagram of the composite insulator 100;

[0019] Figure 2 is a cross-sectional view of the fitting 130 in one embodiment of this application;

[0020] Figure 3 is an enlarged view of point A in Figure 1 in one embodiment of this application;

[0021] Figure 4 is an enlarged view of the connection between the fitting 230 and the mandrel 210 in another embodiment of this application;

[0022] Figure 5 is an enlarged view of the connection between the fitting 330 and the mandrel 310 in another embodiment of this application. Detailed Implementation

[0023] As requested, specific embodiments of this application are disclosed herein. However, it should be understood that the embodiments disclosed herein are merely typical examples of this application and may be embodied in various forms. Therefore, the specific details disclosed herein are not intended to be limiting, but merely to serve as the basis for the claims and as a representative basis for teaching those skilled in the art to apply this application 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.

[0024] In one embodiment, referring to Figure 1, the composite insulator 100 includes a core rod 110, a sheath 120 covering and fixed to the outer periphery of the core rod 110, and a fitting 130 fixedly sleeved at the end of the core rod 110. The core rod 110 is a solid structure with a circular cross-section, specifically a solid rod pultruded from glass fiber impregnated with epoxy resin, possessing good mechanical and electrical insulation properties. In other embodiments, the cross-section of the core rod can also be any other shape, such as rectangular, elliptical, I-shaped, T-shaped, etc. The core rod can also be pultruded from other materials such as aramid fiber impregnated with epoxy resin, depending on actual needs, and no specific limitations are imposed here.

[0025] At least one shed 121 is provided on the sheath 120, and the shed 121 is disposed on the outer wall of the sheath 120. The sheath 120 completely covers and fixes the outer periphery of the core rod 110, but does not cover the part of the core rod 110 that is inserted into the fitting 130 and tightly connected to the inner wall of the fitting 130. Both the sheath 120 and the shed 121 are made of high-temperature vulcanized silicone rubber, and are integrally vacuum-injected to cover and fix the outer periphery of the core rod 110. Integral injection molding of high-temperature vulcanized silicone rubber ensures that there are no air bubbles inside the sheath 120 and the shed 121, and ensures the reliability of the interface adhesion, thus improving the overall external insulation performance and service life of the composite insulator 100. In other embodiments, the sheath and shed can also be made of other rubber materials or insulating materials, and can also be covered and fixed to the outer periphery of the core rod using other processes such as molding, or the sheath and shed can be made separately and then combined together with an adhesive.

[0026] Fitting 130 is an end fitting used to connect composite insulator 100 to a support structure, conductor, equipment, or another composite insulator. In this embodiment, fitting 130 is a ball-and-foot type fitting made of high-strength alloy steel 40Cr profile, possessing reliable mechanical properties. In other embodiments, the fitting can also be a cap-type fitting, a slot-type fitting, a flat-angle-type fitting, a Y-type fitting, or a ring-type fitting, or any other metal accessory that performs a connecting function. It can also be made of other metal materials, and can be designed according to actual needs; no specific limitations are made here. It should be noted that regardless of the type of fitting 130, its connection method with the core rod 110 and the sheath 120 is universal.

[0027] Referring to Figures 1, 2, and 3, the end of the composite insulator 100 employs a multi-seal structure consisting of a sealing ring 140, sealant 180, and a curved surface fit. Specifically, the fitting 130 has a connected first cavity 150 and a second cavity 160 near the end of the core rod 110. The diameter of the second cavity 160 is larger than the diameter of the first cavity 150. The end of the core rod 110 is fixed in the first cavity 150, and the end of the core rod 110 abuts against the bottom wall of the first cavity 150. The sheath 120 extends into the second cavity 160 and abuts against the bottom wall of the second cavity 160. A sealing ring 140 is provided around the sheath 120 in the second cavity 160. The sealing ring 140 abuts against the bottom wall and side wall of the second cavity 160. The end face of the fitting 130 near the sheath 120 is curved. The remaining part of the second cavity 160 is filled with sealant 180. The sealant 180 covers the curved surface and connects with the sheath 120, so that the fitting 130 and the sheath 120 are sealed together. The sealant 180 extends from the second cavity 160 to the curved surface and the sheath 120. The curved surface increases the contact area between the fitting 130 and the sealant 180, thereby further strengthening the sealing connection between the fitting 130 and the sheath 120. At the same time, the sealing ring 140 and the sealant 180 form a double seal at the connection between the sheath 120 and the fitting 130, which can prevent external moisture from entering and causing corrosion and brittle fracture of the core rod 110, reducing the risk of seal failure.

[0028] In this embodiment, the cross-sectional shape and size of the first cavity 150 match the cross-section of the mandrel 110. Specifically, both the first cavity 150 and the mandrel 110 have circular cross-sections, and the inner diameter of the first cavity 150 is approximately equal to the diameter of the mandrel 110. This means the inner diameter of the first cavity 150 can be slightly larger than or equal to the diameter of the mandrel 110, which facilitates fixing the mandrel 110 within the first cavity 150 by means of pressing or other methods, ensuring the connection strength between the fitting 130 and the mandrel 110. In other embodiments, the cross-sections of the first cavity and the mandrel can be set to other shapes, such as rectangles or triangles, or the cross-section of the first cavity can be different from that of the mandrel, as long as a fixed connection between the fitting and the mandrel can be achieved. No specific limitations are imposed here.

[0029] In this embodiment, the mandrel 110 is fixed in the first cavity 150 of the fitting 130 using a crimping process, so that the end of the mandrel 110 abuts against the bottom wall of the first cavity 150. Since the diameter of the second cavity 160 is larger than the diameter of the first cavity 150, the end of the sheath 120 covering the outer periphery of the mandrel 110 can tightly abut against the bottom wall of the second cavity 160, which can provide a certain sealing effect at the interface where the mandrel 110, fitting 130, and sheath 120 are connected. In other embodiments, the mandrel can also be fixed by other methods such as adhesive bonding, as long as a reliable connection between the fitting and the mandrel can be achieved, and no specific limitation is made here.

[0030] Referring to Figure 3, a sealing ring 140 is provided inside the second cavity 160, surrounding the sheath 120. The sealing ring 140 abuts against the bottom wall of the second cavity 160. After the mandrel 110 covered with the sheath 120 is pressed into the first cavity 150 of the fitting 130, the sealing ring 140 is placed at the bottom of the second cavity 160 of the fitting 130, and it is tightly abutted against the side walls of both the sheath 120 and the second cavity 160, forming an interference fit. This produces appropriate elastic deformation, which seals the interface between the mandrel 110 and the fitting 130, preventing external moisture from entering and causing corrosion and brittle fracture of the mandrel 110 and corrosion of the internal structure of the fitting 130. The sealing ring 140 is a closed O-ring made of high-temperature vulcanized silicone rubber. The high-temperature vulcanized silicone rubber sealing ring 140 has excellent aging resistance and can maintain good sealing performance in harsh environments over a long period. In other embodiments, the sealing ring can also be any other shape such as square or U-shaped. The sealing ring can also be an open-type sealing ring, or it can be made of other rubber materials or elastic insulating materials, without specific limitations.

[0031] At least one first sealing groove 170 is provided around the end face of the fitting 130 near the sheath 120, and the end edge of the fitting 130 near the sheath is an arc surface, so that the end face of the fitting 130 near the sheath is a curved surface with a concave-convex structure. The remaining part of the second cavity 160 of the fitting 130 is filled with sealant 180. The sealant 180 covers the curved surface and connects with the sheath 120, so that the fitting 130 and the sheath 120 are sealed together. The curved surface increases the contact area between the fitting 130 and the sealant 180, extends the sealing path, and improves the sealing effect. The sealant 180 covers the entire curved surface of the fitting 130 and extends to the sheath 120, further strengthening the sealing connection between the fitting 130 and the sheath 120. The sealing ring 140, the sealant 180, and the curved surface with the sealing groove 170 work together to form a multi-layer sealing structure at the interface between the sheath 120 and the fitting 130. This prevents external moisture from entering and corroding the internal structure of the fitting 130 and causing corrosion and brittle fracture of the mandrel 110, thus reducing the risk of sealing failure.

[0032] In one embodiment, the outer peripheral surface of the end of the fitting 130 near the sheath 120 is cylindrical, and the end face of the fitting 130 near the sheath 120 is smoothly connected to its outer peripheral surface. The first sealing groove 170 can make the end face of the fitting 130 near the sheath 120 curved, thereby enhancing the sealing effect between the sheath 120 and the fitting 130. The smooth connection between the end face of the fitting 130 and its outer peripheral surface can also reduce the tip structure of the fitting 130 and effectively optimize the electric field.

[0033] Furthermore, the edge of the end face of the fitting 130 near the sheath 120 is surrounded by a protrusion 131, the end of which is an arc surface. This makes the end face of the fitting 130 near the sheath 120 a more complex curved surface. When the remaining part of the second cavity 160 of the fitting 130 is filled with sealant 180 to cover the curved surface and connect it to the sheath 120, the contact area between the sealant 180 and the fitting 130 is further increased, and the sealing path between them is extended, thereby strengthening the sealing effect between the sheath 120 and the fitting 130. The arc surface also effectively reduces the sharp point structure of the fitting 130, effectively optimizing the electric field. In addition, since the composite insulator 100 is usually installed vertically when connected to the grid, the protrusion 131 facilitates the rapid drainage of rainwater along its arc surface, avoiding large water accumulation that could lead to flashover, tripping, and other electrical safety accidents.

[0034] The first sealing groove 170 has a rectangular cross-section for easy processing. In other embodiments, the cross-section of the first sealing groove can also be a circle, triangle, or other arbitrary shape, without specific limitations.

[0035] The sealant 180 is a room temperature vulcanizing silicone rubber, which has a simple sealing process, good sealing performance, and a certain adhesive strength, which helps to seal the connection between the fitting 130 and the sheath 120. In other embodiments, the sealant can be other rubber materials or insulating sealing materials, as long as they can seal the connection between the mandrel and the fitting, and no specific limitations are made here.

[0036] In another embodiment, referring to Figure 4, to further enhance the sealing effect of the end sealing structure of the composite insulator, the sidewall of the second cavity of the fitting 230 is provided with a concave-convex sealing interface. Specifically, the contact area between the second cavity and the sealing ring 240 is set as concave-convex. When the core rod 210 is pressed into the first cavity, the sealing ring 240 will tightly abut against the concave-convex surface of the sidewall of the second cavity, the bottom wall of the second cavity, and the outer side of the sheath 220. The concave-convex surface of the sidewall of the second cavity can extend the sealing path, prevent external moisture from entering, and increase the contact area between the sealing ring 240 and the fitting 230, thereby increasing the friction between the sealing ring 240 and the fitting 230 and reducing the risk of movement of the sealing ring 240. In other embodiments, the concave-convex sealing interface can also be located on the entire inner surface of the second cavity. When the remaining part of the second cavity is filled with sealant, the sealant will fully and tightly contact the concave-convex surface in the second cavity, further extending the sealing path, preventing external moisture from entering, and enhancing the sealing effect. The shape of the concave-convex interface can be wavy, sawtooth, or irregular, etc., and no specific restrictions are imposed here. Other structures of the composite insulator are as described above and will not be repeated here.

[0037] In another embodiment, referring to Figure 5, to further enhance the sealing effect of the end sealing structure of the composite insulator, a second sealing groove 332 is provided on the side wall of the second cavity of the fitting 330. The second sealing groove 332 engages with the sealing ring 340. Specifically, the second sealing groove 332 is provided at the contact point between the second cavity and the sealing ring 340. When the core rod 310 is pressed into the first cavity, the sealing ring 340 will be tightly engaged in the second sealing groove 332 and closely abut against the bottom wall of the second cavity of the fitting 330 and the outer side of the sheath 320. This can further extend the sealing path and prevent external moisture from entering. At the same time, the setting of the second sealing groove 332 restricts the position of the sealing ring 340, which can prevent the sealing ring 340 from shifting, resulting in a more stable sealing effect. Other structures of the composite insulator are as described above and will not be repeated here.

[0038] The second sealing groove 332 has a rectangular cross-section for ease of processing. In other embodiments, the cross-section of the second sealing groove can also be circular, triangular, or other arbitrary shapes to engage with sealing rings of different shapes; no specific limitations are imposed here.

[0039] This application also provides a method for manufacturing a composite insulator 100, which specifically includes the following steps:

[0040] S11: High-temperature vulcanized silicone rubber molding sheath 120 is injected into the outer periphery of the middle part of the mandrel 110 to obtain the first insulator preform.

[0041] Prior to this step, step S01 involves preparing the core rod 110 using a pultrusion molding process. Specifically, firstly, several fiber yarns are impregnated with resin and fed into a molding device for high-temperature curing to form a core rod preform; then, a traction device pulls the core rod preform along the pultrusion direction, continuously molding the core rod preform; finally, a cutting device cuts the core rod preform to a preset length to obtain a core rod 110 of the corresponding specifications. The molding device includes a pultrusion die for curing the resin-impregnated fiber yarns into the corresponding shape. The pultrusion die can be selected based on the specific structure of the core rod 110 required for the composite insulator 100. Furthermore, the traction device and cutting device can be existing equipment, as long as they can achieve the corresponding functions; no specific limitations are imposed here.

[0042] In this step, firstly, a coupling agent is coated on the outer periphery of the middle part of the mandrel 110 and then dried; then the mandrel 110 is placed into the injection mold of the injection molding machine, silicone rubber raw material is added, and high-temperature vulcanized silicone rubber is injected into the outer periphery of the middle part of the mandrel 110. After cooling, a sheath 120 is formed, thereby obtaining the first insulator preform. The middle part of the core rod 110 refers to the portion of the core rod 110 excluding the areas at both ends used to connect to the fittings 130. Therefore, the overall length of the sheath injection area in the middle of the core rod 110 must match its fitting connection area. Otherwise, if the injection area of ​​the sheath 120 on the core rod 110 is too long, the length of the connection area of ​​the fitting 130 on the core rod 110 will be shortened, causing the fitting 130 to fail to connect properly and affecting the mechanical strength of the composite insulator 100. If the injection area of ​​the sheath 120 on the core rod 110 is too short, a gap will remain between the sheath 120 and the fitting 130 after the fitting 130 is connected to the end of the core rod 110, affecting the sealing performance of the composite insulator 100.

[0043] In one application scenario, a skirt 121 also needs to be fabricated around the outer periphery of the sheath 120. Specifically, the sheath 120 and the skirt 121 can be integrally molded. That is, after changing and installing the corresponding injection mold in the injection molding machine, the mandrel 110 is placed in it, and the sheath 120 and the skirt 121 are integrally injection molded around the outer periphery of the middle part of the mandrel 110 to obtain the first insulator preform. The specific injection process is as described above and will not be repeated here. Alternatively, the sheath 120 and the skirt 121 can be fabricated sequentially. That is, the skirt 121 can be fabricated around the outer periphery of the pre-formed sheath 120 using an extrusion and umbrella-insertion process. The extrusion and umbrella-insertion process can be implemented using existing technology and is not specifically limited here.

[0044] S12: Fittings 130 are pressed onto both ends of the core rod 110 to obtain the second insulator preform.

[0045] In this step, a fitting 130 is first crimped onto one end of the core rod 110. Specifically, a fitting 130 is manually or mechanically fitted onto one end of the core rod 110, so that one end of the core rod 110 abuts against the bottom wall of the first cavity 150, and one end of the sheath 120 abuts against the bottom wall of the second cavity 160; then, a crimping machine is used to crimp and fix the fitting 130 to one end of the core rod 110. Next, a fitting 130 is also crimped onto the other end of the core rod 110, that is, the two ends of the core rod 110 are reversed, and another fitting 130 is fitted onto and crimped to fix the other end of the core rod 110, thus obtaining the second insulator prefabricated component. The specific fitting and crimping process is as described above and will not be repeated here. The crimping machine and corresponding operating methods can be implemented using existing technology and are not specifically limited here.

[0046] S13: The target area where the core rod 110, sheath 120 and fitting 130 come into contact is sealed to obtain the composite insulator 100.

[0047] In this step, the sealing process includes steps S131 and S132, as follows:

[0048] S131: A sealing ring 140 is provided around the sheath 120 in the second cavity 160, so that the sealing ring 140 abuts against the bottom wall and the side wall of the second cavity 160.

[0049] In one application scenario, the sealing ring 140 is an open-type sealing ring. In this step, the sealing ring 140 is first placed in the second cavity 160 of the fitting 130 at one end of the mandrel 110. Then, the sealing ring 140 is moved and adjusted so that it surrounds the sheath 120, and the open ends of the sealing ring 140 are neatly aligned or overlapped, and the sealing ring 140 abuts against the bottom wall and side wall of the second cavity 160, thus completing the installation of one sealing ring 140. The sealing ring 140 in the fitting 130 at the other end of the mandrel 110 is also installed according to the above steps, which will not be described in detail here.

[0050] In another application scenario, the sealing ring 140 is a closed sealing ring. After step S11 and before step S12, step S111 is included: first, two sealing rings 140 are respectively fitted onto both ends of the sheath 120 to prevent them from being unable to fit along the outer periphery of the sheath 120 after the end of the mandrel 110 is pressed against the fitting 130, because the inner diameter of the sealing ring 140 is smaller than the outer periphery of the fitting 130. In step S131, the sealing ring 140 pre-fitted onto one end of the sheath 120 is placed in the second cavity 160 of the corresponding fitting 130, and then the sealing ring 140 is moved and adjusted so that it abuts against the bottom wall and side wall of the second cavity 160, thereby completing the installation of one sealing ring 140. The sealing ring 140 at the other end of the sheath 120 is also installed according to the above steps, and will not be described again here.

[0051] In another application scenario, the side wall of the second cavity of the fitting 230 is provided with a concave-convex sealing interface. Therefore, regardless of the structure of the sealing ring 240, in this step, the sealing ring 240 needs to be moved and adjusted so that the sealing ring 240 abuts against the bottom wall of the second cavity, the concave-convex surface of the side wall of the second cavity, and the outer side of the sheath 220. The remaining installation operations are as described above and will not be repeated.

[0052] In another application scenario, the second cavity of the hardware 330 is provided with a second sealing groove 332. Therefore, regardless of the structure of the sealing ring 340, in this step, the sealing ring 340 needs to be moved and adjusted so that the sealing ring 340 is engaged in the second sealing groove 332 and abuts against the bottom wall of the second cavity and the outer side of the sheath 320. The remaining installation operations are as described above and will not be repeated.

[0053] S132: Fill the remaining portion of the second cavity 160 with sealant 180, so that the sealant 180 covers the curved surface of the hardware 130 and is sealed to the sheath 120.

[0054] In this step, the second insulator prefabricated component is first placed vertically by manual labor or tooling equipment such as supports, and a fitting 130 located below the second insulator prefabricated component is sealed with sealant. That is, the remaining part of the second cavity 160 of the fitting 130 is filled with sealant 180, so that the sealant 180 covers the curved surface of the fitting 130 and seals it with the sheath 120. Then, the sealant 180 is cured and formed by room temperature curing or heat curing. Then, the two ends of the second insulator prefabricated component are turned over so that it is still placed vertically, and the other fitting 130 located below the second insulator prefabricated component is sealed with sealant as described above, to obtain the composite insulator 100.

[0055] When sealing the fitting 130, after filling the remaining portion of the second cavity 160 of the fitting 130 with a sufficient amount of sealant 180, the excess sealant 180 is removed using a tool such as a right-angle scraper. Specifically, one right-angle edge of the right-angle scraper is first placed close to the core rod 110, and the other adjacent right-angle edge abuts against the end of the fitting 130 near the sheath 120; then, the right-angle scraper is rotated horizontally 360° around the core rod 110, so that the sealant 180 smoothly covers the curved surface of the fitting 130 and seals with the sheath 120, effectively preventing uneven distribution of the sealant 180 in the second cavity 160 from affecting the sealing effect of the composite insulator 100.

[0056] The composite insulator of this application forms a multi-layer sealing structure at the interface between the sheath and the fitting by using sealant, sealing ring and curved surface, which can prevent external moisture from entering and causing corrosion and brittle fracture of the core rod, and reduce the risk of sealing failure.

[0057] Meanwhile, by providing a concave-convex sealing interface or a second sealing groove on the side wall of the second cavity of the fitting, this application can further extend the sealing path, prevent external moisture from entering, and enhance the sealing effect; and can further limit the position of the sealing ring, prevent the sealing ring from shifting, and make the sealing effect more stable.

[0058] Furthermore, the manufacturing method of the composite insulator in this application is simple to operate and has high production efficiency, which can ensure the sealing performance of the manufactured composite insulator.

[0059] The technical content and features of this application have been disclosed above. However, it is understood that, based on the inventive concept of this application, those skilled in the art can make various changes and improvements to the above-described structure 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 to which this application pertains and are within the scope of protection of the claims of this application.

Claims

1. A composite insulator, comprising a core rod, a sheath covering the outer periphery of the core rod, and hardware fixedly sleeved at the end of the core rod, characterized in that, The fitting has a first cavity and a second cavity connected to each other near the end of the mandrel. The diameter of the second cavity is larger than the diameter of the first cavity. The end of the mandrel is fixed in the first cavity and abuts against the bottom wall of the first cavity. A sealing ring is provided in the second cavity and abuts against the bottom wall of the second cavity. The end face of the fitting near the sheath is curved. The remaining part of the second cavity is filled with sealant. The sealant covers the curved surface and connects to the sheath, so that the fitting and the sheath are sealed together.

2. The composite insulator as described in claim 1, characterized in that, The sealing ring simultaneously and tightly abuts against both the sheath and the sidewall of the second cavity.

3. The composite insulator as described in claim 1, characterized in that, The sealant is made of room temperature vulcanizing silicone rubber.

4. The composite insulator as described in claim 1, characterized in that, The sheath is tightly pressed against the bottom wall of the second cavity.

5. The composite insulator as described in claim 1, characterized in that, At least one first sealing groove is provided around the end face of the fitting near the sheath to form the curved surface.

6. The composite insulator as described in claim 5, characterized in that, The first sealing groove has a rectangular cross-section.

7. The composite insulator as described in claim 1, characterized in that, The sidewall of the second cavity is provided with a concave-convex sealing interface.

8. The composite insulator as described in claim 1, characterized in that, The second cavity has a second sealing groove on its side wall, and the second sealing groove engages with the sealing ring.

9. The composite insulator as described in claim 1, characterized in that, The fitting has a protrusion connected around the edge of the end face near the sheath, and the end of the protrusion is an arc surface to form the curved surface.

10. The composite insulator as described in claim 1, characterized in that, The end face of the fitting near the sheath is smoothly connected to its outer peripheral face.

11. A method for manufacturing a composite insulator, characterized in that, The method for manufacturing the composite insulator as described in any one of claims 1-10 specifically includes the following steps: S11: High-temperature vulcanized silicone rubber is injected into the outer periphery of the middle part of the core rod to form a sheath, thus obtaining the first insulator preform. S12: Fittings are pressed onto both ends of the core rod to obtain the second insulator preform; S13: Perform sealing treatment at the target area where the core rod, the sheath, and the fittings contact to obtain the composite insulator.

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