Mold pin for preventing discharge electrode coating film, mold, mold manufacturing method, and surge arrester production method

Abstract

This invention relates to the field of lightning arrester manufacturing technology, specifically to a mold needle for anti-discharge electrode coating, a mold, a mold manufacturing method, and a lightning arrester production method. The mold needle includes a needle rod for forming a discharge gap during lightning arrester production; symmetrical flexible abutment surfaces are provided on both sides of one end of the needle rod. Each flexible abutment surface includes a mounting surface located on the side of the needle rod end and a flexible pad fixed to the mounting surface; the flexible pad includes a concave spherical abutment portion and an extension portion located above the spherical abutment portion; the extension portion is higher than the horizontal plane where the center of the spherical discharge electrode is located; when multiple needle rods are spaced apart, the flexible abutment surfaces on opposite sides of adjacent needle rods are adapted to abut against the spherical surfaces on both sides of the same spherical discharge electrode. By flexibly sealing the spherical surface of the spherical discharge electrode with the flexible abutment surface, the hard contact of the existing mold needle is replaced with a flexible sealing abutment, which solves the problem of silicone rubber coating on the spherical discharge electrode during the vulcanization and composite jacketing of existing mold needles.

Description

Technical Field

[0001] This invention relates to the field of lightning arrester manufacturing technology, specifically to a mold needle for anti-discharge electrode coating, a mold, a mold manufacturing method, and a lightning arrester production method. Background Technology

[0002] Multi-chamber gap surge arresters consist of multiple discharge chambers, each containing spaced discharge electrodes. The gaps between the discharge electrodes connect to the outside environment, allowing flashover conduction during a lightning strike through these gaps. The discharge electrodes in the arrester are typically spherical (with a spherical discharge end). These electrodes are pre-installed within the arrester's composite jacket, which is generally formed through a vulcanization process. During vulcanization, the jacket material (usually silicone rubber) easily overflows onto the surface of the discharge electrodes, forming a coating. During vulcanization, tools are required to ensure that discharge gaps exist between the electrodes and that the discharge ends of the electrodes are exposed.

[0003] Patent No. CN209552339U discloses a mold needle for producing multi-chamber gap surge arresters, including a discharge gap control end. The discharge gap control end has a spindle-shaped cross-section in the horizontal direction, with the larger cross-section end connected to one end of a gap channel control part. The other end of the gap channel control part is connected to a fixed base. The discharge gap control end, gap channel control part, and fixed base are integrally molded. Spherical grooves are symmetrically arranged on both sides of the discharge gap control end. In use, the discharge electrode is placed on the spherical concave surfaces of the two discharge gap control ends to prevent rubber overflow during vulcanization and the formation of a coating on the discharge electrode. However, due to the small size of the discharge electrode and discharge gap, the spherical concave surface of the mold needle rigidly abuts against the spherical electrode. The structure of the mold needle and discharge electrode has production errors. In actual surge arrester production, the mold needle cannot perfectly seal against the spherical discharge electrode, resulting in small gaps between a few spherical electrodes and the contact surface of the mold needle, leading to a few electrodes having a coating. Summary of the Invention

[0004] The purpose of this invention is to optimize the coating of spherical electrodes and provide a mold needle, mold, mold manufacturing method, and surge arrester production method for anti-discharge electrode coating.

[0005] The technical solution adopted in this invention is: a mold needle with an anti-discharge electrode coating, comprising, The needle rod is used to form a discharge gap when producing a surge arrester; symmetrical flexible abutment surfaces are provided on both sides of one end of the needle rod, the flexible abutment surfaces are tough and include a spherical concave structure; When multiple needle bars are spaced apart, the spherical concave surfaces of the flexible contact surfaces on the opposing sides of adjacent needle bars are adapted to abut against both sides of the same spherical discharge electrode.

[0006] Furthermore, the flexible contact surface includes a mounting surface located on the side of the needle bar end and a flexible pad fixed on the mounting surface; the flexible pad includes a concave spherical contact portion and an extension portion located on the upper side of the spherical contact portion; the extension portion is higher than the horizontal plane where the center of the spherical discharge electrode is located.

[0007] Furthermore, a connecting hole is provided at one end of the needle bar corresponding to the mounting surface, and a connecting rib is provided inside the connecting hole. The two ends of the connecting rib are respectively connected to the flexible pads on both sides.

[0008] Furthermore, the mounting surface and the peripheral side of the needle bar are connected by an arc-shaped transition.

[0009] Furthermore, the extension protrudes towards the side near the spherical discharge electrode to form a snap-fit ​​protrusion. The spacing between the snap-fit ​​protrusions on the opposite sides of adjacent needle bars is smaller than the diameter of the spherical discharge electrode, which is used to snap the spherical discharge electrode.

[0010] Furthermore, the snap-fit ​​protrusion includes a lower support section and an upper traction section, with the connection between the lower support section and the upper traction section forming a protrusion apex.

[0011] Furthermore, the spherical contact portion is in a surface-sealed contact with the spherical discharge electrode when the spherical discharge electrode is installed, and is in a compressed state.

[0012] Furthermore, the extension extends upward and is an arc-shaped surface for sliding against the spherical discharge electrode in the vertical direction; the vertical line where the center of the spherical discharge electrode is located coincides with the central axis of the arc-shaped surface; the radius of the arc-shaped surface is smaller than the radius of the spherical discharge electrode.

[0013] Furthermore, the top of the extension has a chamfered structure on the side closest to the center of the sphere.

[0014] Furthermore, the minimum distance d between the two concave surfaces of the resilience pads on the needle bar is 0.23-0.33 mm.

[0015] Furthermore, the connecting holes include side holes distributed along the edge of the flexible pad; the connecting ribs connect two flexible pads along the edge of the flexible pad.

[0016] Furthermore, the side hole has a rectangular, arc-shaped, or U-shaped cross-section on the vertical plane.

[0017] Furthermore, the connecting hole also includes a central hole located in the middle of the resilience pad, and a connecting rib is provided inside the central hole.

[0018] Furthermore, the toughness pads and connecting ribs on both sides of the needle bar are integrally formed.

[0019] Furthermore, the toughness pad is made of perfluoroether rubber or high-phenyl modified silicone rubber.

[0020] The present invention also provides a lightning arrester mold with anti-discharge electrode coating, comprising an upper mold assembly and a lower mold assembly with mold pins provided by the present invention for anti-discharge electrode coating; the lower mold assembly is provided with a vulcanizing groove for forming a vulcanizing cavity after mold closing; a plurality of pin insertion holes are vertically opened on the vulcanizing groove, each pin insertion hole including a pin guide section and a bottom limiting section, the top surface of the pin guide section is located on the bottom surface of the vulcanizing groove, the bottom surface of the pin guide section is connected to the top surface of the bottom limiting section, the bottom surface of the bottom limiting section is located on the bottom surface of the pin insertion hole, and the plurality of pin insertion holes are arranged side by side at equal intervals along the length direction of the vulcanizing groove; the upper mold assembly is used to form the vulcanizing cavity of the vulcanized lightning arrester after being combined with the lower mold.

[0021] According to the lightning protection device mold provided by the present invention, the bottom end of the needle rod is provided with a limiting surface located on the side for preventing rotation, and the inner wall of the needle rod insertion hole includes an abutting surface adapted to abut the limiting surface.

[0022] According to the lightning protection device mold provided by the present invention, the lower module includes a lower module and a lower template. The top of the lower module is provided with the vulcanization groove and the needle rod insertion hole. The lower template is fixed to the bottom of the lower module for vertically fixing the needle rod. The installation phase of multiple needle rods is the same, so that the needle rod can coincide with the adjacent needle rod after translation.

[0023] According to the lightning protection device mold provided by the present invention, the bottom of the upper mold is provided with a vulcanization groove, and when the upper mold and the lower mold are closed, the two vulcanization grooves are connected to form a vulcanization cavity.

[0024] This invention also provides a method for manufacturing a lightning arrester mold with a protective electrode coating, comprising: A flexible pad is formed on both sides of the needle bar end with a connecting hole by vulcanization. The flexible pads on both sides of the needle bar are connected as one piece by the connecting ribs formed by vulcanization in the connecting hole. The first vulcanization temperature of the flexible pad is 170-200℃, the duration is 20-40min, and the holding pressure is 10-16MPa. The second vulcanization temperature is 220-300℃ and the duration is 4-28h. Multiple needle rods equipped with flexible pads are inserted into the needle rod insertion holes of the lower module in the same phase and at even intervals, so that the flexible pads are located in the vulcanization tank of the lower module, the top surface of the vertical limiting block at the bottom end of the needle rod abuts against the top surface of the bottom limiting section of the needle rod insertion hole on the lower module, and the limiting surface on the needle rod abuts against the abutting surface on the hole wall of the needle rod insertion hole. The lower template is fixedly connected to the bottom of the lower module, so that the lower template abuts against the bottom end of the needle bar; The prefabricated upper module, which matches the lower module, and the lower module are combined to form the vulcanization cavity of the vulcanized lightning arrester.

[0025] This invention also provides a method for manufacturing a multi-chamber gap surge arrester, using a mold needle with an anti-discharge electrode coating provided by this invention. The manufacturing method includes... Multiple needle rods are fixedly installed on the arrester mold with the same phase and even spacing, so that the flexible contact surface at the end of the needle rod is located in the vulcanization cavity of the arrester mold; A high-voltage electrode is placed at one end of the vulcanizing chamber, and a mounting base containing a low-voltage electrode is placed at the other end. A spherical discharge electrode is placed between the needle bars and abuts against the flexible pad on the opposite side of the adjacent needle bars; After the mold is closed, vulcanized rubber is injected into the vulcanization cavity and vulcanized according to the vulcanization process to form a surge arrester; The mold opening and withdrawal of the mold pin creates a discharge gap on the surge arrester.

[0026] The beneficial effects of this invention include: 1. Symmetrical flexible contact surfaces are provided on both sides of one end of the needle bar. When multiple needle bars are spaced apart, the flexible contact surfaces on the opposite sides of adjacent needle bars are adapted to abut against the spherical surfaces on both sides of the same spherical discharge electrode. The flexibility of the contact surface abuts against the spherical surface of the spherical discharge electrode, which can ensure that the flexible contact surface and the spherical surface of the spherical discharge electrode are sealed and fitted together, avoiding small gaps between the spherical discharge electrode and the mold needle. This can solve the problem of silicone rubber coating on the spherical discharge electrode during vulcanization composite jacketing. 2. The flexible abutment surface is installed with a flexible pad on the mounting surface of the needle rod side. The flexible pad seals the spherical discharge electrode through the spherical abutment part to ensure that the silicone rubber will not overflow onto the surface of the spherical discharge electrode to form a film during the vulcanization of the composite jacket, which would affect the electrical parameters of the surge arrester. The extension part can increase the connection area between the flexible pad and the mounting surface of the needle rod, improve the fixing effect, and prevent the flexible pad from separating from the mounting surface when the mold needle is demolded. 3. The extension protrudes towards the spherical discharge electrode to form a snap-fit ​​protrusion. The distance between the snap-fit ​​protrusions on the opposite sides of the two needle rods is less than the diameter of the discharge electrode. When the discharge electrode is inserted between adjacent needle rods, the spherical abutment part abuts against the spherical surface of the spherical discharge electrode, and the snap-fit ​​protrusion is located above the horizontal plane of the center of the spherical discharge electrode to snap the spherical discharge electrode and prevent the spherical discharge electrode from becoming loose. 4. The extension extends upwards and slides vertically against the arc-shaped surface of the spherical discharge electrode. This design facilitates the insertion of the spherical discharge electrode from above. 5. The needle bar is connected to the flexible pads on both sides by a connecting rib through the connecting hole, which can enhance the reliability of the flexible pads on the needle bar and prevent the flexible pads from separating from the needle bar when the mold needle is ejected. 6. The connecting holes are distributed on the edge of the flexible pad to connect two flexible pads, which can enhance the reliability of the edge of the flexible pad being fixed to the needle bar and prevent the edge of the flexible pad from lifting up and separating from the needle bar when the mold needle is ejected. 7. The connecting hole includes a central hole located in the middle of the toughness pad. The connecting ribs connect the two middle parts of the toughness pad at both ends of the central hole, which can strengthen the connection between the middle part of the toughness pad and the needle bar. The toughness pad is made of perfluoroether rubber or high phenyl modified silicone rubber, which has good temperature resistance and can withstand high temperatures above 250℃. It will not be deformed during the vulcanization of the composite jacket and has good temperature resistance and mechanical properties. 8. The lower mold is equipped with a vulcanizing tank, and the needle rods are arranged in the vulcanizing tank at intervals in the same phase. After the lower mold is combined with the upper mold, a vulcanizing chamber can be formed for vulcanization molding of the composite jacket, which is convenient to use. 9. The needle bar is installed by matching the limiting surface on the needle bar with the abutting surface on the lower module, which makes it easy to install multiple needle bars in the same phase on the lower module, ensuring homogeneous installation of needle bars and avoiding the inability of the spherical discharge electrode to be installed between the tough pads on the opposite sides of adjacent needle bars. 10. The production method of the surge arrester provided by the present invention makes full use of the structural characteristics of the mold needle of the anti-discharge electrode coating provided by the present invention. The toughness pads on both sides of the needle rod are vulcanized and molded into one piece, and are vulcanized and connected to the needle rod at the same time. This can ensure the connection strength between the toughness pads and the needle rod, and prevent the toughness pads from loosening when the mold needle is demolded. The spherical discharge electrode is sealed and abutted by the toughness pads on the opposite sides of the adjacent needle rods. The installation of the spherical discharge electrode is stable, and small gaps are avoided between the mold needle and the spherical discharge electrode. This solves the problem of silicone rubber coating on the spherical discharge electrode when the existing mold needle vulcanizes the composite jacket.

[0027] The present invention relates to a mold needle with a coating for an anti-discharge electrode. The needle bar has symmetrical flexible abutment surfaces on both sides. The flexible abutment surfaces have an inwardly concave arc-shaped spherical structure, which facilitates the flexible abutment surfaces on the opposite sides of adjacent needle bars to abut against the two sides of the spherical discharge electrode. The flexible abutment surfaces are in flexible contact with the spherical discharge electrode, and a flexible sealing abutment method is adopted to avoid the formation of small gaps between the spherical discharge electrode and the mold needle. This can solve the problem of silicone rubber coating on the spherical discharge electrode during the vulcanization composite outer sleeve of the existing mold needle. Attached Figure Description

[0028] Figure 1 : A schematic diagram of the structure of the flexible contact surface at the end of the needle bar; Figure 2 : A schematic diagram of a three-dimensional structure with evenly spaced needle bars; Figure 3 :for Figure 2 A magnified structural diagram of part A in the diagram; Figure 4 A schematic diagram of an implementation scheme for a resilience pad; Figure 5 :for Figure 4 A magnified structural diagram of part B in the diagram; Figure 6 : Another schematic diagram of the implementation scheme of the resilience pad; Figure 7 Schematic diagram of the lightning protection device mold; Figure 8 : A three-dimensional structural diagram of the lower module of the lightning protection device; Figure 9 : A top view of the lower module of the lightning protection device; Figure 10 :for Figure 9 A schematic diagram of the cross-section at point AA; Figure 11 : A schematic diagram of the structure of the mold needle installed on the lower mold; Figure 12 : A schematic diagram of a surge arrester manufactured using a surge arrester mold; Figure 13 : A schematic diagram of the discharge gap of a surge arrester produced using a surge arrester mold; Wherein: 1-Needle bar; 11-Mounting surface; 12-Connecting hole; 121-Center hole; 122-Side hole; 13-Limiting surface; 14-Vertical limiting block; 2-Tough pad; 21-Spherical abutment part; 22-Extension part; 23-Snap-fit ​​protrusion; 231-Lower support section; 232-Upper traction section; 24-Connecting rib; 3-Lower module; 31-Lower module; 311-Vulcanizing tank; 312-Needle bar insertion hole; 313-Needle bar guide section; 314-Bottom limiting section; 32-Lower template; 4-Spherical discharge electrode; 5-Upper module; 6-Mounting base. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and the drawings are not drawn to scale and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0032] This invention relates to a mold needle for coating a spherical discharge electrode 4, used in the production of gap surge arresters. Symmetrical flexible abutment surfaces are provided on both sides of one end of the needle rod 1. When multiple needle rods 1 are spaced apart, the flexible abutment surfaces on the opposing sides of adjacent needle rods 1 are adapted to abut against the spherical surfaces on both sides of the same spherical discharge electrode 4. The flexibility of the abutment surfaces ensures a tight seal between the flexible abutment surfaces and the spherical surfaces of the spherical discharge electrode 4, preventing small gaps between the spherical discharge electrode 4 and the mold needle's contact surface. This solves the problem of silicone rubber coating on the spherical discharge electrode 4 during vulcanization composite jacketing.

[0033] Example 1 A mold needle with a coated anti-spherical discharge electrode 4, specifically, such as Figure 1-5 As shown, the device includes a needle rod 1, which is made of a rigid material. Symmetrical flexible contact surfaces are provided on both sides of one end of the needle rod 1. These flexible contact surfaces are flexible and include a concave spherical structure, approximating the spherical cut surface of the needle rod 1, making the horizontal cut section at the end of the needle rod 1 spindle-shaped. When multiple needle rods 1 are spaced apart, the flexible contact surfaces on the opposing sides of adjacent needle rods 1 serve as mounting positions for spherical discharge electrodes 4. The flexible contact surfaces on the opposing sides of adjacent needle rods 1 are adapted to flexibly contact the spherical surfaces on both sides of the same spherical discharge electrode 4. In use, at least two needle rods 1 are spaced apart in the same phase. The spherical discharge electrode 4 is placed between the flexible contact surfaces on the opposing sides of two adjacent needle rods 1, allowing the spherical surfaces on both sides of the spherical discharge electrode 4 to flexibly seal against the flexible contact surface. This avoids gaps between the spherical discharge electrode 4 and the mold needle, thus solving the problem of silicone rubber coating on the spherical discharge electrode 4 during vulcanization composite jacketing.

[0034] In one implementation, such as Figure 2-5 As shown, the flexible contact surface includes a mounting surface 11 located on the side of the end of the needle bar 1 and a flexible pad 2 fixed on the mounting surface 11. The flexible pad 2 seals against the spherical discharge electrode 4 through the spherical contact portion 21, ensuring that the silicone rubber will not overflow onto the discharge end surface of the spherical discharge electrode 4 to form a film during the vulcanization of the composite jacket. The flexible pad 2 includes a concave spherical contact portion 21 and an extension portion 22 located on the upper side of the spherical contact portion 21. The extension portion 22 is higher than the horizontal plane where the center of the spherical discharge electrode 4 is located (in the installed state of the spherical discharge electrode 4). When the spherical discharge electrode 4 is installed between the flexible contact surfaces on the opposite sides of adjacent needle bars 1, the spherical contact portion 21 abuts against the spherical surface of the spherical discharge electrode 4, and the extension portion 22 is located above the horizontal plane of the center of the spherical discharge electrode 4, which can increase the connection area between the flexible pad 2 and the mounting surface 11, improve the fixing effect, and prevent the flexible pad 2 from separating from the mounting surface 11 when the mold needle is removed.

[0035] Preferably, the mounting surface 11 is connected to the peripheral side of the needle bar 1 in an arc transition, which is an arc chamfer structure.

[0036] Based on the flexible contact surface including the resilient pad 2, in one embodiment, such as Figure 4-5 As shown, the extension 22 protrudes towards the side near the spherical discharge electrode 4 to form a snap-fit ​​protrusion 23. The distance between the snap-fit ​​protrusions 23 on the opposing sides of adjacent needle bars 1 (the straight-line distance through the center of the spherical discharge electrode 4) is less than the diameter of the spherical discharge electrode 4, which is used to snap the spherical discharge electrode 4. Before the spherical discharge electrode 4 is installed, the snap-fit ​​protrusion 23 is located inside the spherical surface of the spherical discharge electrode 4. During the installation of the spherical discharge electrode 4, the part of the spherical discharge electrode 4 located at the horizontal plane of the center of the sphere abuts against the snap-fit ​​protrusion 23. The spherical discharge electrode 4 is pressed down further, causing the snap-fit ​​protrusion 23 to deform, so that the distance between the snap-fit ​​protrusions 23 between adjacent needle bars 1 allows the spherical discharge electrode 4 to pass through. When the spherical surface of the spherical discharge electrode 4 abuts against the spherical surface abutment part 21, the snap-fit ​​protrusion 23 squeezes the spherical discharge electrode 4 above the horizontal plane of the center of the spherical discharge electrode 4 to achieve snap-fit, improve the snap-fit ​​effect, and prevent the spherical discharge electrode 4 from loosening.

[0037] The snap-fit ​​protrusion 23 is used to snap the spherical discharge electrode 4 onto the horizontal plane of the center of the spherical discharge electrode 4. It is not necessary to continuously seal and abut the spherical surface of the spherical discharge electrode 4 in the circumferential direction (with the vertical line of the center of the sphere as the axis). Multiple snap-fit ​​protrusions 23 can be arranged circumferentially at intervals. Preferably, the snap-fit ​​protrusion 23 continuously seals and abuts the spherical surface of the spherical discharge electrode 4 in the circumferential direction.

[0038] Based on the extension 22 protruding towards the side near the spherical discharge electrode 4, a snap-fit ​​protrusion 23 is formed, such as Figure 5 As shown, the snap-fit ​​protrusion 23 includes a lower support section 231 and an upper traction section 232. The connection between the lower support section 231 and the upper traction section 232 forms a protrusion apex. The lower support section 231 and the upper traction section 232 are connected by an arc-shaped transition. The lower support section 231 is connected to the lower spherical abutment portion 21 by an arc-shaped transition. When the spherical discharge electrode 4 is inserted between the tough pads 2 on the opposite sides of the adjacent needle rod 1, when the spherical discharge electrode 4 squeezes the upper traction section 232, the lower support section 231 provides upward support to the upper traction section 232, and the upper traction section 232 provides traction to the protrusion apex. After the snap-fit ​​protrusion 23 is deformed by pressure, the spherical discharge electrode 4 moves down to abut the spherical abutment portion 21. When the center of the ball is below the apex of the snap-fit ​​protrusion 23, the upper traction section 232 pulls the protrusion apex upward to reset, and cooperates with the lower support section 231 to press against the spherical surface of the spherical discharge electrode 4 to realize the snap-fit ​​of the spherical discharge electrode 4.

[0039] In one implementation scheme, such as Figure 5As shown, the spherical abutment portion 21 is in surface-sealed contact with the spherical discharge electrode 4 when the spherical discharge electrode 4 is installed, and is in a compressed state. That is, when the spherical abutment portion 21 is not installed with the spherical discharge electrode 4, the concave surface of the spherical abutment portion 21 is located inside the sphere of the outline of the spherical discharge electrode 4 when it is installed. The dotted line in the figure represents the position of the concave surface of the flexible pad 2 before the spherical discharge electrode 4 is installed, and the dotted line represents the horizontal plane of the sphere center. The minimum distance between the concave surfaces of the two flexible pads 2 on the needle rod 1 is preferably 0.23-0.33 mm. After the spherical discharge electrode 4 is installed, the discharge gap distance d can be maintained at 0.2-0.3 mm.

[0040] In some implementations, such as Figure 2-3 As shown, a connecting hole 12 is provided at one end of the needle bar 1 corresponding to the mounting surface 11. A connecting rib 24 is provided inside the connecting hole 12, and the two ends of the connecting rib 24 are respectively connected to the flexible pads 2 on both sides. By installing the connecting rib 24 to connect the flexible pads 2 on both sides through the through connecting hole 12, the reliability of the flexible pads 2 installed on the needle bar 1 can be enhanced, and the flexible pads 2 can be prevented from separating from the needle bar 1 when the mold needle is ejected.

[0041] Based on the fact that the needle bar 1 has a connecting hole 12, such as Figure 3 As shown, the connecting hole 12 includes side holes 122 distributed on the mounting surface 11 of the needle bar 1 along the edge of the flexible pad 2; the connecting rib 24 connects the two flexible pads 2 at the edge of the flexible pad 2. The side holes 122 can have various cross-sectional shapes, especially, but not limited to, rectangular, arc-shaped, or U-shaped cross-sections on the vertical plane; the arrangement of the side holes 122 can enhance the reliability of the edge of the flexible pad 2 being fixed to the needle bar 1, and can prevent the edge of the flexible pad 2 from lifting and separating from the needle bar 1 when the mold needle is ejected.

[0042] The needle bar 1 may also be provided with a connecting hole 12 on the extension 22 corresponding to the toughness pad 2. For example, the mounting surface 11 is provided with a side hole 122 corresponding to the extension 22. The extensions 22 of the toughness pads 2 on both sides of the needle bar 1 are connected by the connecting ribs 24 in the side holes 122.

[0043] Based on the fact that the needle bar 1 has a connecting hole 12, such as Figure 3 As shown, the connecting hole 12 also includes a central hole 121 on the mounting surface 11 of the needle bar 1 corresponding to the center of the flexible pad 2, and a connecting rib 24 is provided in the central hole 121; the flexible pad 2 and the connecting rib 24 on both sides of the needle bar 1 are integrally formed. The flexible pad 2 and the connecting rib 24 are preferably integrally formed by vulcanization process and vulcanized and fixed to the needle bar 1 at the same time, so as to have a higher connection strength with the needle bar 1.

[0044] The toughness pad 2 of this invention is a high-temperature toughness pad 2. The conventional material of the composite outer jacket is ordinary silicone rubber. The vulcanization temperature of silicone rubber is generally 160-200℃. The high-temperature toughness pad 2 only needs to be stable in properties during the hot vulcanization molding of silicone rubber. For example, the toughness pad 2 can be made of perfluoroether rubber or high phenyl modified silicone rubber, etc., which are resistant to high temperatures above 250℃.

[0045] In actual use, the needle bar 1 has symmetrical mounting surfaces 11 on both sides of one end. The mounting surfaces 11 include a spherical structure. The needle bar 1 has connecting holes 12 corresponding to the mounting surfaces 11. The connecting holes 12 include a central hole 121 in the middle of the mounting surface 11 and side holes 122 on the periphery of the edge. Two flexible pads 2 are vulcanized and connected to the two mounting surfaces 11 and connected as a whole by connecting ribs 24 formed by vulcanization in the connecting holes 12. The flexible pad 2 includes a spherical abutment portion 21 and an extension portion 22 provided on the upper side of the spherical abutment portion 21. 22 is higher than the horizontal plane where the center of the spherical discharge electrode 4 is located. The extension 22 protrudes towards the side close to the spherical discharge electrode 4 to form a snap-fit ​​protrusion 23. The snap-fit ​​protrusion 23 includes a lower support section 231 and an upper traction section 232. The connection between the lower support section 231 and the upper traction section 232 forms a protrusion apex. The distance between the protrusion apexes of the snap-fit ​​protrusions 23 on the opposite side of the adjacent needle rods 1 is smaller than the diameter of the spherical discharge electrode 4. The toughness pad 2 is in a compressed state after the spherical discharge electrode 4 is installed. Multiple needle rods 1 are in phase and evenly spaced.

[0046] Example 2 The difference between this embodiment and Embodiment 1 lies in the structure of the extension 22 of the resilience pad 2, such as... Figure 6 As shown, the extension 22 of the flexible pad 2 extends upward and is an arc-shaped surface used to slide and abut against the spherical discharge electrode 4 vertically. The vertical line containing the center of the spherical discharge electrode 4 (its outline during installation) coincides with the central axis of the arc-shaped surface. The radius of the arc-shaped surface is smaller than the radius of the spherical discharge electrode 4. After the spherical discharge electrode 4 is installed, the spherical abutment part 21 exerts an upward force on the spherical discharge electrode 4 from below, making it easy for the spherical discharge electrode 4 to not adhere tightly to the spherical abutment part 21. Since the radius of the arc-shaped surface is smaller than the radius of the spherical discharge electrode 4, when the spherical discharge electrode 4 is inserted between the two arc-shaped surfaces and abuts against the spherical abutment part 21, the two arc-shaped surfaces press against the spherical discharge electrode 4 above the horizontal plane of the center of the sphere, generating damping for the upward movement of the spherical discharge electrode 4, which counteracts the upward force generated by the spherical abutment part 21, ensuring a sealed fit between the spherical discharge electrode 4 and the spherical abutment part 21. The top of the extension 22 near the center of the sphere has a chamfered structure, which facilitates the insertion of the spherical discharge electrode 4 from above.

[0047] Example 3 This embodiment relates to a lightning protection device mold with a discharge-resistant electrode coating, such as... Figure 7-10As shown, the device includes an upper module 5, a lower module 3, and a mold pin provided by the present invention. The upper module 5 is used to form a vulcanization cavity for a vulcanized lightning arrester after being closed with the lower module 3. The mold pin is located on the lower module 3, which has a vulcanization groove 311 for forming a vulcanization cavity after being closed. The lower module 3 has multiple needle rod insertion holes 312 that are connected to the vulcanization groove 311 in the axial direction perpendicular to the vulcanization groove. Each needle rod insertion hole 312 includes a needle rod guide section 313 and a bottom limiting section 314. The top surface of the needle rod guide section 313 is located on the bottom surface of the vulcanization groove 311, and the bottom surface of the needle rod guide section 313 is connected to the top surface of the bottom limiting section 314. The bottom surface of the bottom limiting section 314 is located on the bottom surface of the needle rod insertion hole 312. The multiple needle rod insertion holes 312 are arranged side by side at equal intervals along the length of the vulcanization groove 31. Multiple needle rods 1 are spaced apart along the length of the vulcanizing tank 311. The installation phases of the multiple needle rods 1 are the same, so that after the needle rod 1 is translated, it can coincide with the adjacent needle rod 1, and the flexible contact surfaces of the adjacent needle rods 1 facing each other are adapted to contact the two sides of the spherical discharge electrode 4. The lower module 3 is provided with a vulcanizing tank 311, which forms a receiving cavity for vulcanizing the composite outer jacket when it is closed with the upper module 5.

[0048] The vulcanizing groove 311 is not limited to an arc-shaped groove, but can be a rectangular or other structure; preferably, the bottom of the upper module 5 is also provided with a vulcanizing groove 311, and when the upper module 5 and the lower module 3 are closed, the two vulcanizing grooves 311 are connected to form a vulcanizing cavity. In a specific embodiment, the upper module 5 includes an upper template and an upper module located at the bottom of the upper template. The bottom of the upper module is provided with a vulcanizing groove 311, the cross-section of which is semi-circular. When the upper module 5 and the lower module 3 are closed, the two semi-circular vulcanizing grooves 311 are connected to form a vulcanizing cavity; the vulcanizing groove 311 has pre-reserved skirt grooves along its axial direction to form multiple skirts when vulcanizing the surge arrester, avoiding the need to install the skirts after the surge arrester body is formed.

[0049] like Figure 1 and Figure 11 As shown, the bottom end of the needle bar 1 is provided with a limiting surface 13 located on the side for preventing rotation, and the lower module 3 is provided with an abutting surface adapted to abut the limiting surface 13; in a specific embodiment, the bottom end of the needle bar 1 is provided with a vertical limiting block 14, and the limiting surface 13 is provided on the side of the vertical limiting block 14; the vertical limiting block 14 can be in the form of a D-shaped structure or other polygonal structure, and the plane of the D-shaped structure serves as the limiting surface 13; the inner wall of the needle bar insertion hole 312 forms an abutting surface, and the limiting surface 13 is provided on the side of the end of the needle bar 1. When the needle bar 1 is inserted and installed on the lower module 3, the limiting surface 13 abuts against the abutting surface, and the top surface of the vertical limiting block 14 abuts against the top surface of the bottom limiting section 314, thereby vertically limiting (upwardly limiting) the needle bar 1 while restricting the rotation of the needle bar 1, and installing and positioning the phase of the needle bar 1 to ensure that multiple needle bars 1 are installed in the same phase.

[0050] like Figure 7-10As shown, the lower module 3 includes a lower module 31 and a lower template 32. The lower module 31 has a vulcanizing groove 311 at the top and a needle rod insertion hole 312 at the bottom that connects to the vulcanizing groove 311. The lower template 32 is fixed to the bottom end of the lower module 31 for vertically fixing the needle rod 1. The top surface of the lower template 32 abuts against the bottom end face of the needle rod 1 (lower limit), and cooperates with the bottom limiting section 314 to vertically limit the needle rod 1. The installation phase of multiple needle rods 1 is the same, so that the needle rod 1 can coincide with the adjacent needle rod 1 after translation.

[0051] Preferably, the lower module 31 is provided with a tearing groove on the outer side of the edge of the vulcanizing tank 311 (with a small spacing, for example, 0.1-0.3mm). When the composite jacket is vulcanized, the silicone rubber material flows from the vulcanizing tank 311 to the tearing groove under high pressure, forming tear strips on both sides of the composite jacket. When the composite jacket is vulcanized, the tear strips are like rubber bands, which makes it easy to tear and clean the rubber residues of the composite jacket located between the upper module 5 and the lower module 3.

[0052] Example 4 S1. This embodiment provides a method for manufacturing a lightning arrester mold with a protective discharge electrode coating, including the following steps: S2. A flexible pad 2 is integrally vulcanized on both sides of the end of the needle rod 1 with the connecting hole 12, so that the flexible pads 2 on both sides of the needle rod 1 are connected as one unit through the connecting rib 24 formed by vulcanization in the connecting hole 12; the flexible pad 2 adopts a multi-stage vulcanization process, the first stage vulcanization temperature is 170-200℃, the duration is 20-40min, and the holding pressure is 10-16MPa, the second stage vulcanization temperature is 220-300℃, and the duration is 4-28h. The specific vulcanization time of the two stages depends on the thickness of the flexible pad 2 and the compounded rubber material. The quality is determined; the spherical concave surfaces of the toughness pads 2 on both sides of the end of the needle rod 1 are symmetrical; in specific operation, one end of the needle rod 1 is placed into the mold of the toughness pad 2, and the compound rubber (perfluoroether rubber or high phenyl modified silicone rubber and other vulcanization pretreatments) is injected into the mold cavity of the toughness pad. The two toughness pads 2 are connected into one piece by the connecting rib 24 through the hot vulcanization process. At the same time, the two toughness pads 2 are vulcanized and fixed to the mounting surface 11 of the needle rod 1. Then, the two toughness pads 2 are placed in the oven and heated in a stepwise manner for two-stage vulcanization, so that the toughness pads 2 can withstand temperatures above 250℃. S3. Insert multiple needle rods 1 equipped with flexible pads 2 into the needle rod insertion holes 312 of the lower module 31 in the same phase and at even intervals, so that the flexible pads 2 are located in the vulcanization tank 311 of the lower module 31, the top surface of the vertical limiting block 14 at the bottom end of the needle rod 1 abuts against the top surface of the bottom limiting section 314 of the needle rod insertion hole 312 on the lower module 31, and the limiting surface 13 on the needle rod 1 abuts against the abutting surface on the hole wall of the needle rod insertion hole 312. S4. The lower template 32 is fixedly connected to the bottom of the lower module 31, so that the lower template 32 abuts against the bottom end of the needle bar 1; the lower template 32 can be bolted to the lower module 31 to fix the needle bar 1 on the lower module 3; S5. The prefabricated upper module 5, which matches the lower module 3, is molded together with the lower module 3 to form the vulcanization cavity of the vulcanized lightning arrester. When producing the upper module 5, the upper module with the vulcanization groove 311 at the bottom is fixed to the bottom of the upper template to form the upper module 5. After the upper module 5 and the lower module 3 are molded together, the upper and lower vulcanization grooves 311 are connected to form a complete vulcanization cavity.

[0053] Example 5 This embodiment provides a method for manufacturing a multi-chamber gap surge arrester, using a mold needle with an anti-discharge electrode coating provided by the present invention. The manufacturing method includes the following steps: S100. Multiple needle rods 1 are fixedly installed on the arrester mold in the same phase and at uniform intervals, so that the flexible contact surface at the end of the needle rod 1 is located in the vulcanization cavity of the arrester mold. S200. A high-voltage electrode is placed at one end of the vulcanization chamber and a mounting base containing a low-voltage electrode is placed at the other end. The mounting base serves as the mounting base for the surge arrester formed by vulcanization. S300, A spherical discharge electrode is placed between the needle rods 1 and abuts against the flexible pads 2 on the opposite sides of the adjacent needle rods 1; the flexible pads 2 on both sides of the needle rod 1 at one end (outermost end) of the vulcanizing chamber abut against the spherical surface of the spherical discharge electrode 4 and the high-voltage electrode respectively, and the flexible pads 2 on both sides of the needle rod 1 at the other end of the vulcanizing chamber abut against the spherical surface of the spherical discharge electrode 4 and the low-voltage electrode respectively. S400, after mold closing, vulcanized rubber is injected into the vulcanization cavity, and vulcanized according to the vulcanization process to form a surge arrester; S500, the ejection mold needle forms a discharge gap on the surge arrester. When the mold is ejected, the tough pad 2 separates from the spherical surface of the spherical discharge electrode 4, exposing the discharge end of the spherical discharge electrode 4. At the same time, the needle rod 1 is ejected on the surge arrester to form a discharge chamber, so that the discharge gap is connected to the outside. The spherical discharge electrode 4 is vulcanized and fixed on the surge arrester.

[0054] In actual production, an insulating core can be placed in the vulcanization chamber according to the requirements of the surge arrester product. One end of the insulating core is connected to the mounting base, and the insulating core is separated from the spherical discharge electrode 4 and the discharge chamber by silicone rubber.

[0055] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A mold needle with an anti-discharge electrode coating, characterized in that: include The needle rod (1) is used to form a discharge gap when producing a surge arrester. Symmetrical flexible contact surfaces are provided on both sides of one end of the needle rod (1). The flexible contact surfaces include a mounting surface (11) located on the side of the end of the needle rod (1) and a tough pad (2) fixed on the mounting surface (11). The tough pad (2) includes a concave spherical contact part (21) and an extension part (22) located on the upper side of the spherical contact part (21). The extension part (22) is higher than the horizontal plane where the center of the spherical discharge electrode (4) is located. A connecting hole (12) is provided at one end of the needle rod (1) corresponding to the mounting surface (11). A connecting rib (24) is provided in the connecting hole (12). The two ends of the connecting rib (24) are integrally formed with the tough pads (2) on both sides of the needle rod (1). When multiple needle bars (1) are spaced apart, the spherical concave surfaces of the flexible contact surfaces on the opposite sides of adjacent needle bars (1) are adapted to abut against both sides of the same spherical discharge electrode (4).

2. The mold needle with anti-discharge electrode coating as described in claim 1, characterized in that: The extension (22) protrudes towards the side close to the spherical discharge electrode (4) to form a snap-fit ​​protrusion (23). The spacing between the snap-fit ​​protrusions (23) on the opposite side of the adjacent needle bar (1) is smaller than the diameter of the spherical discharge electrode (4) and is used to snap the spherical discharge electrode (4).

3. The mold needle with an anti-discharge electrode coating as described in claim 1, characterized in that: The extension (22) extends upward and is an arc-shaped surface for sliding against the spherical discharge electrode (4) in the vertical direction; the vertical line where the center of the spherical discharge electrode (4) is located coincides with the central axis of the arc-shaped surface; the radius of the arc-shaped surface is smaller than the radius of the spherical discharge electrode (4).

4. The mold needle with anti-discharge electrode coating as described in claim 1, characterized in that: The connecting hole (12) includes a side hole (122), which corresponds to the edge of the toughness pad (2); the two ends of the connecting rib (24) inside the side hole (122) are integrally formed with the edges of the toughness pad (2) on both sides of the needle bar (1).

5. The mold needle with an anti-discharge electrode coating as described in claim 4, characterized in that: The connecting hole (12) also includes a central hole (121), which corresponds to the middle of the toughness pad (2). A connecting rib (24) is provided inside the central hole (121). The connecting rib (24) inside the central hole (121) is integrally formed with the toughness pads (2) on both sides of the needle bar (1). The toughness pad (2) is made of perfluoroether rubber or high phenyl modified silicone rubber.

6. A lightning arrester mold with a discharge-resistant electrode coating, characterized in that: The system includes an upper module (5) and a lower module (3) with a mold needle having a discharge-resistant electrode coating as described in any of claims 1-5. The lower module (3) has a vulcanizing groove (311) for forming a vulcanizing cavity after mold closing. A plurality of needle rod insertion holes (312) are vertically opened on the vulcanizing groove (311). Each needle rod insertion hole (312) includes a needle rod guide section (313) and a bottom limiting section (314). The top surface of the needle rod guide section (313) is located on the bottom surface of the vulcanizing groove (311). The bottom surface of the needle rod guide section (313) is connected to the top surface of the bottom limiting section (314). The bottom surface of the bottom limiting section (314) is located on the bottom surface of the needle rod insertion hole (312). The plurality of needle rod insertion holes (312) are arranged side by side at equal intervals along the length direction of the vulcanizing groove (311). The upper module (5) is used to form the vulcanization cavity of the vulcanized lightning arrester after being molded together with the lower module (3).

7. The lightning arrester mold with anti-discharge electrode coating as described in claim 6, characterized in that: The needle bar (1) has a limiting surface (13) located on the side for preventing rotation at the bottom end, and the inner wall of the needle bar insertion hole (312) includes an abutting surface adapted to abut the limiting surface (13).

8. The lightning arrester mold with anti-discharge electrode coating as described in claim 7, characterized in that: The lower module (3) includes a lower module (31) and a lower template (32). The lower module (31) has the vulcanizing groove (311) at the top and the needle bar insertion hole (312) at the bottom. The lower template (32) is fixed to the bottom of the lower module (31) for vertically fixing the needle bar (1). The installation phase of multiple needle bars (1) is the same, so that the needle bar (1) can overlap with the adjacent needle bar (1) after translation.

9. A method for manufacturing a lightning arrester mold with a discharge-resistant electrode coating, characterized in that: include, A flexible pad (2) is formed by vulcanizing on both sides of the end of the needle rod (1) through which the connecting hole (12) is provided. The flexible pads (2) on both sides of the needle rod (1) are connected as one unit through the connecting rib (24) formed by vulcanization in the connecting hole (12). The first vulcanization temperature of the flexible pad (2) is 170-200℃, the duration is 20-40min, and the holding pressure is 10-16MPa. The second vulcanization temperature is 220-300℃ and the duration is 4-28h. Multiple needle rods (1) equipped with a toughness pad (2) are inserted into the needle rod insertion hole (312) of the lower module (31) in the same phase and at even intervals, so that the toughness pad (2) is located in the vulcanization tank (311) of the lower module (31), the top surface of the vertical limiting block (14) at the bottom end of the needle rod (1) abuts against the top surface of the bottom limiting section (314) of the needle rod insertion hole (312) on the lower module (31), and the limiting surface (13) on the needle rod (1) abuts against the abutting surface on the hole wall of the needle rod insertion hole (312); The lower template (32) is fixedly connected to the bottom of the lower module (31), so that the lower template (32) abuts against the bottom end of the needle bar (1); The prefabricated upper module (5) that matches the lower module (3) is molded together with the lower module (3) to form the vulcanization cavity of the vulcanized lightning arrester.

10. A method for producing a multi-chamber gap surge arrester using a mold needle with an anti-discharge electrode coating as described in claim 1, characterized in that: Multiple needle rods (1) are fixedly installed on the arrester mold in the same phase and at uniform intervals, so that the flexible contact surface at the end of the needle rod (1) is located in the vulcanization cavity of the arrester mold; A high-voltage electrode is placed at one end of the vulcanizing chamber, and a mounting base containing a low-voltage electrode is placed at the other end. A spherical discharge electrode (4) is placed between the needle bars (1) and abuts against the tough pad (2) on the opposite side of the adjacent needle bars (1); After the mold is closed, vulcanized rubber is injected into the vulcanization cavity and vulcanized according to the vulcanization process to form a surge arrester; The ejection pin creates a discharge gap on the surge arrester.

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