Self-adaptive universal fixture for replacing insulator of power transmission line

Abstract

The invention discloses a self-adaptive universal fixture for replacing an insulator of a power transmission line, and aims to overcome the defects that an existing fixture is poor in universality and cannot adapt to replacement of insulators of different models. The clamping device comprises two clamping heads and a locking rod connected between the two clamping heads, a plurality of clamping jaws capable of moving telescopically are installed on the clamping heads, elastic pre-tightening pieces are connected between the clamping jaws and the clamping heads, and the ends of the clamping jaws are provided with inner clamping stress parts and outer clamping stress parts. The self-adaptive universal fixture for replacing the insulator of the power transmission line is good in universality, can adapt to replacement of insulators of different models, is convenient to operate, and is beneficial to improving the maintenance efficiency.

Description

Technical Field

[0001] The invention relates to a power grid maintenance fixture, and more particularly to an adaptive universal fixture for replacing insulators of power transmission lines. Background Art

[0002] With the continuous development of China's power grid construction, power users are increasingly demanding higher reliability and uninterrupted power supply from distribution networks. Live-line operations have also achieved significant progress. When an insulator fails or explodes on a line, maintenance personnel must promptly detect and rectify the problem, replacing the failed insulator to eliminate the hidden danger and maintain safe and stable operation of the transmission line. This replacement method uses closed-type clamps. The currently used closed-type insulator clamps (DBK type) can only be used to replace insulators of the same model from the same manufacturer; that is, the clamps and insulators must be matched one-to-one. Because the clamping joints of insulator caps vary from manufacturer to manufacturer and model to model, insulators manufactured by a manufacturer can only be disassembled and assembled using the clamps provided by that manufacturer. Due to multiple suppliers and major overhauls and technical upgrades, a single transmission line often contains a variety of insulators of varying tonnages, models, and manufacturers. This results in a complex system of clamps, requiring maintenance personnel to carry multiple types of clamps. This not only increases the number of spare parts, consuming significant funds and storage space, but also increases the burden on operators, directly reducing maintenance efficiency. Summary of the Invention

[0003] In order to overcome the above-mentioned shortcomings, the present invention provides an adaptive universal fixture for replacing insulators of transmission lines, which has good versatility and can adapt to the replacement of insulators of different models, facilitates operation, and is conducive to improving maintenance efficiency.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solution: an adaptive universal clamp for replacing transmission line insulators, comprising two clamping heads and a locking rod connected between the two clamping heads, a plurality of telescopically movable clamping claws are installed on the clamping heads, an elastic pre-tightening member is connected between the clamping claws and the clamping heads, and an internal clamping force-bearing part and an external clamping force-bearing part are provided at the ends of the clamping claws.

[0005] When replacing insulators on transmission lines, the fixture is installed on the insulator cap, and the two clamping heads can be in any direction. After the clamping is in place, the locking rod is turned to move the two clamping heads toward each other. Under the action of the elastic preload, the end of the clamping claw presses against the outer wall of the insulator cap. When the clamping heads move into place, the inner clamping force-bearing part of the clamping claw on one clamping head presses against the inner outer wall of one insulator cap, and the outer clamping force-bearing part of the clamping claw on the other clamping head presses against the outer wall of the other insulator cap. Under the action of the elastic preload, the clamping claw is clamped on the outer wall of the insulator cap. Because the contact point on the outer wall of the insulator cap with the clamping claw has a slope, the two clamping heads can be locked when they approach each other, preventing axial and radial movement of the entire fixture. After the fixture is installed, the insulator replacement and maintenance between the two clamping heads can be carried out.

[0006] Because the claws are mounted on the mounting head and can be telescopically moved, and an elastic preload is installed between the claws and the mounting head, the fixture can be installed on insulator caps of different sizes and specifications, making it suitable for replacing insulators of different sizes and models. Maintenance workers only need to carry one type of fixture, which helps reduce the number of spare parts, alleviates the burden on operators, and improves maintenance efficiency.

[0007] The self-adaptive universal fixture for replacing transmission line insulators of the present invention has good versatility, can adapt to the replacement of insulators of different models, facilitates operation, and is conducive to improving maintenance efficiency.

[0008] Preferably, the clamping claws on the two clamping heads are arranged to be inclined in directions away from each other.

[0009] The clamping jaws are tilted to withstand a greater clamping force between the two clamping heads.

[0010] Preferably, the inclination angle between the clamping claw and the axis of the clamping head is 40-60 degrees.

[0011] The inclination angle of the clamping claw is set reasonably to ensure that the clamping claw firmly clamps the insulator steel cap.

[0012] Preferably, a first notch and a second notch are provided at the end of the clamping claw, the edge of the first notch close to the center side of the clamping head forms an inner clamping force portion, and the edge of the second notch close to the center side of the clamping head forms an outer clamping force portion.

[0013] A first notch and a second notch are provided at the end of the clamping claw to facilitate clamping of the insulator steel cap.

[0014] Preferably, the first notch and the second notch are connected end to end, the side wall of the first notch includes a longitudinal section and a transverse section, and the longitudinal section is inclined; the side wall of the second notch includes a vertical section and an axial section, and there is an arc transition between the vertical section and the axial section.

[0015] This structural setting can match the structure of the outer wall of the insulator steel cap, ensuring that there is enough space at the end position of the claw to avoid interference with the outer wall of the insulator steel cap.

[0016] In another solution, the first notch and the second notch are connected end to end, the side wall of the first notch includes a longitudinal section and a transverse section, and the longitudinal section is inclined; the side wall of the second notch is a concave arc structure.

[0017] The side wall of the second notch is in a concave arc-shaped structure, which is beneficial to improving the structural strength of this position.

[0018] Preferably, the elastic preload member is a tension spring.

[0019] The tension spring has a simple structure, is easy to install and has good use effect.

[0020] Preferably, mounting holes are provided on the clamping head and the clamping claw correspondingly, and the clamping claw is movably plug-in connected to the mounting hole; a slide groove is provided on the clamping claw, a connecting pin is provided in the slide groove, a positioning pin is connected to the side wall of the mounting hole, a tension spring is connected between the connecting pin and the positioning pin, and the tension spring is installed in the slide groove.

[0021] The jaws are installed in the mounting holes, ensuring smooth and reliable telescopic movement. A tension spring, tightened between the connecting pin and the positioning pin, provides the clamping force needed to securely hold the jaw ends against the outer wall of the insulator cap. The chute provides space for the tension spring and positioning pin to avoid interference.

[0022] Preferably, the clamping head includes two C-shaped connectors, one end of the two connectors is hinged together, and the other end of the two connectors is detachably connected together.

[0023] The two connectors are assembled to form a clamping head, which is convenient for installation on the insulator steel cap.

[0024] Preferably, the locking rod includes a threaded sleeve and two screws, the two screws are respectively fastened to the two clamping heads, the threads on the two screws rotate in opposite directions, and the threaded sleeve is threadedly connected between the two screws.

[0025] The screw sleeve rotates, and the threads of the screw sleeve and the screw rod cooperate to move the two screw rods toward each other or away from each other, thereby realizing the clamping and disassembly of the fixture.

[0026] Compared with the prior art, the beneficial effects of the present invention are: the adaptive universal fixture for replacing transmission line insulators of the present invention has good versatility, can adapt to the replacement of insulators of different models, facilitates operation, and is conducive to improving maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the practical state structure of the present invention; Figure 2It is a structural schematic diagram of the present invention; Figure 3 is a cross-sectional view of Example 1 of the present invention; Figure 4 is a cross-sectional view of Example 2 of the present invention; Figure 5 is a side view of embodiment 3 of the present invention; Figure 6 This is a force analysis diagram of the clamping force-bearing portion within the clamping claw of the present invention; Figure 7 This is a force analysis diagram of the outer clamping force-bearing portion of the clamping claw of the present invention; Figure 8 It is a mathematical model diagram of the force on the claw of the present invention; Figure 9 This is a bending force analysis diagram of the outer clamping force-bearing portion of the clamping claw of the present invention; Figure 10 This is a bending force analysis diagram of the clamping force-bearing portion within the clamping claw of the present invention; Figure 11 This is a force analysis diagram of the mounting hole when the outer clamping force-bearing portion of the clamping claw of the present invention is subjected to force; Figure 12 This is a force analysis diagram of the mounting hole when the clamping force-bearing portion of the clamping claw of the present invention is subjected to force; Figure 13 This is a force analysis diagram of the connection between the clamping head and the locking rod of the present invention; Figure 14 This is an analysis diagram of the force conditions of the claws of four types of insulators of the present invention; Figure 15 This is a mathematical model diagram of the specific shear force of the inner clamping claw on the clamp of the present invention; Figure 16 This is a mathematical model diagram of the specific shear force of the outer clamping claw on the clamp of the present invention; In the figure: 1. Clamping head, 2. Screw sleeve, 3. Screw, 4. Twisting head, 5. Bidirectional ratchet wrench, 6. Connector, 7. Connecting head, 8. Mounting head, 9. Claw, 10. Elastic preload member, 11. Mounting hole, 12. Slide groove, 13. Connecting pin, 14. Positioning pin, 15. First notch, 16. Second notch, 17. Inner clamping force-bearing part, 18. Outer clamping force-bearing part, 19. Longitudinal section, 20. Transverse section, 21. Vertical section, 22. Axial section, 23. Step on outer wall of insulator steel cap, 24. Raised ring, 25. Insulator, 26. Insulator steel cap, 27. Connecting column, 28. Insertion slot, 29. Sleeve, 30. Connecting rod. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example 1: A universal adaptive fixture for replacing insulators on transmission lines (see attached Figure 1 To the attached Figure 3 ), comprises two clamping heads 1 and a locking rod connected between the two clamping heads, the locking rod comprises a nut 2 and two screws 3, the two screws are respectively tightly connected with the two clamping heads, the threads on the two screws rotate in opposite directions, and the nut is threadedly connected between the two screws. A twisting head 4 is provided on the outer wall of the nut, and a wrench is clamped on the twisting head and rotates to drive the nut to rotate. The wrench adopts a bidirectional ratchet wrench 5, and the bidirectional ratchet wrench is directly pre-installed on the nut. The clamping head comprises two C-shaped connectors 6, one end of the two connectors is hinged together, and the other end of the two connectors is detachably connected together. Two locking rods are connected between the two clamping heads, and the ends of the two locking rods are connected to the same connector of the clamping head. A connector 7 is provided on the connector corresponding to the screw, and a U-shaped mounting head 8 is provided at the end of the screw, and the mounting head is inserted into the connector and fastened by a pin. Several claws 9 that can be telescopically moved are installed on the clamping head, and the number of the claws is determined as needed. In the present embodiment, five claws are evenly installed on each clamping head. An elastic pre-tightening member 10 is connected between the clamping claw and the clamping head, and an inner clamping force-bearing portion and an outer clamping force-bearing portion are provided at the end of the clamping claw.

[0029] The claws on the two clamping heads are tilted away from each other and closer to the center of the clamping heads. The tilt angle between the claws and the axis of the clamping heads is 40-60 degrees. In this embodiment, the tilt angle between the claws and the axis of the clamping heads is 45 degrees.

[0030] The elastic preload element is a tension spring. The clamping head and the clamping claw are provided with obliquely arranged mounting holes 11, each extending through the clamping head. The mounting hole has a rectangular cross-section, and the clamping claw is movably connected to the mounting hole. A slide groove 12 is provided on the clamping claw, and a connecting pin 13 is provided in the slide groove. A positioning pin 14 is connected to the side wall of the mounting hole. The tension spring is connected between the connecting pin and the positioning pin and is installed in the slide groove.

[0031] The claws are arranged radially, with a first notch 15 and a second notch 16 provided at the ends of the claws. The edge of the first notch near the center of the clamping head forms an inner clamping force-bearing portion 17, and the edge of the second notch near the center of the clamping head forms an outer clamping force-bearing portion 18. Both the first notch and the second notch are arranged toward the center of the clamping head. The first notch and the second notch are connected end to end. The side wall of the first notch includes a longitudinal section 19 and a transverse section 20, and the longitudinal section is arranged at an angle; the side wall of the second notch includes a vertical section 21 and an axial section 22, and the vertical and axial sections have an arc transition.

[0032] The outer wall of the insulator cap is shaped like a stepped shaft. The step 23 on the outer wall of the insulator cap transitions into a circular arc, and the external clamping force-bearing portion of the claw rests on the arc-shaped step. A V-shaped raised ring 24 is provided near the end of the outer wall of the insulator cap, and the external clamping force-bearing portion rests on the raised ring. Insulator 25 is mounted on insulator cap 26. A connecting post 27 is provided at one end of the insulator cap, and a slot 28 is provided at the other end. The connecting post on one adjacent insulator cap fits into the slot on the other cap to achieve connection.

[0033] When replacing insulators on transmission lines, the fixture is installed on the insulator cap, and the two clamping heads can be in any direction. After the clamping is in place, the locking rod is turned to move the two clamping heads toward each other. Under the action of the elastic preload, the end of the clamping claw presses against the outer wall of the insulator cap. When the clamping heads move into place, the inner clamping force-bearing part of the clamping claw on one clamping head presses against the inner outer wall of one insulator cap, and the outer clamping force-bearing part of the clamping claw on the other clamping head presses against the outer wall of the other insulator cap. Under the action of the elastic preload, the clamping claw is clamped on the outer wall of the insulator cap. Because the contact point on the outer wall of the insulator cap with the clamping claw has a slope, the two clamping heads can be locked when they approach each other, preventing axial and radial movement of the entire fixture. After the fixture is installed, the insulator replacement and maintenance between the two clamping heads can be carried out.

[0034] Because the claws are mounted on the mounting head and can be telescopically moved, and an elastic preload is installed between the claws and the mounting head, the fixture can be installed on insulator caps of different sizes and specifications, making it suitable for replacing insulators of different sizes and models. Maintenance workers only need to carry one type of fixture, which helps reduce the number of spare parts, alleviates the burden on operators, and improves maintenance efficiency.

[0035] Example 2: A universal adaptive fixture for replacing insulators on transmission lines (see attached Figure 4), comprises two clamping heads and a locking rod connected between the two clamping heads, the locking rod comprises a screw sleeve and two screw rods, the two screw rods are respectively tightly connected with the two clamping heads, the threads on the two screw rods rotate in opposite directions, and the screw sleeve is threadedly connected between the two screw rods. A twisting head is set on the outer wall of the screw sleeve, and a wrench is clamped on the twisting head and rotates to drive the screw sleeve to rotate. The wrench adopts a bidirectional ratchet wrench, and the bidirectional ratchet wrench is directly pre-installed on the screw sleeve. The clamping head comprises two C-shaped connectors, one end of the two connectors is hinged together, and the other end of the two connectors is detachably connected together. Two locking rods are connected between the two clamping heads, and the ends of the two locking rods are connected to the same connector of the clamping head. A connector is set on the connector corresponding to the screw rod, and a U-shaped installation head is set on the end of the screw rod. The installation head and the connector are inserted and fastened by pins. Several claws that can be telescopically moved are installed on the clamping head. The number of claws is determined as needed. In the present embodiment, five claws are evenly installed on each clamping head. An elastic pre-tightening component is connected between the clamping claw and the clamping head, and an inner clamping force-bearing part and an outer clamping force-bearing part are arranged at the end of the clamping claw.

[0036] The claws on the two clamping heads are tilted away from each other and closer to the center of the clamping heads. The tilt angle between the claws and the axis of the clamping heads is 40-60 degrees. In this embodiment, the tilt angle between the claws and the axis of the clamping heads is 45 degrees.

[0037] The elastic preload element is a tension spring. The clamping head and the clamping claw are provided with obliquely arranged mounting holes, each extending through the clamping head. The mounting holes are rectangular in cross-section, and the clamping claw is movably connected to the mounting holes. A slide groove is provided on the clamping claw, and a connecting pin is provided in the slide groove. A positioning pin is connected to the side wall of the mounting hole. The tension spring is connected between the connecting pin and the positioning pin and is installed in the slide groove.

[0038] The claws are radially arranged, with a first notch and a second notch at their ends. The edge of the first notch near the center of the mounting head forms the inner clamping force-bearing portion, while the edge of the second notch near the center of the mounting head forms the outer clamping force-bearing portion. Both the first and second notches are positioned toward the center of the mounting head. The first and second notches are connected end to end. The sidewalls of the first notch include a longitudinal section and a transverse section, with the longitudinal section being arranged at an angle; the sidewalls of the second notch are concave and curved.

[0039] The outer wall of the insulator cap is shaped like a stepped shaft, with the step transitioning into a circular arc. The external clamping force-bearing portion of the claw rests against the arc-shaped step. A V-shaped raised ring is provided near the end of the outer wall of the insulator cap, with the external clamping force-bearing portion resting against the raised ring. The insulator is mounted on the insulator cap, with a connecting post at one end and a slot at the other. The connecting post on one adjacent insulator cap fits into the slot on the other cap to achieve connection.

[0040] When replacing insulators on transmission lines, the fixture is installed on the insulator cap, and the two clamping heads can be in any direction. After the clamping is in place, the locking rod is turned to move the two clamping heads toward each other. Under the action of the elastic preload, the end of the clamping claw presses against the outer wall of the insulator cap. When the clamping heads move into place, the inner clamping force-bearing part of the clamping claw on one clamping head presses against the inner outer wall of one insulator cap, and the outer clamping force-bearing part of the clamping claw on the other clamping head presses against the outer wall of the other insulator cap. Under the action of the elastic preload, the clamping claw is clamped on the outer wall of the insulator cap. Because the contact point on the outer wall of the insulator cap with the clamping claw has a slope, the two clamping heads can be locked when they approach each other, preventing axial and radial movement of the entire fixture. After the fixture is installed, the insulator replacement and maintenance between the two clamping heads can be carried out.

[0041] Because the claws are mounted on the mounting head and can be telescopically moved, and an elastic preload is installed between the claws and the mounting head, the fixture can be installed on insulator caps of different sizes and specifications, making it suitable for replacing insulators of different sizes and models. Maintenance workers only need to carry one type of fixture, which helps reduce the number of spare parts, alleviates the burden on operators, and improves maintenance efficiency.

[0042] Example 3: A universal adaptive fixture for replacing insulators on transmission lines (see attached Figure 5 ), including two clamping heads and a locking rod connected between the two clamping heads, the locking rod includes a screw sleeve and two screws, the two screws are respectively tightly connected to the two clamping heads, the threads on the two screws rotate in opposite directions, and the screw sleeve is threadedly connected between the two screws. A twisting head is provided on the outer wall of the screw sleeve, and the wrench is clamped on the twisting head and rotated to drive the screw sleeve to rotate. The wrench adopts a bidirectional ratchet wrench, and the bidirectional ratchet wrench is directly pre-installed on the screw sleeve. A sliding sleeve 29 is mounted on a bidirectional ratchet wrench, and a connecting rod 30 is hinged on the sliding sleeve. The other end of the connecting rod is hinged on another bidirectional ratchet wrench, and the connecting rod has an arc-shaped structure. The synchronous rotation of the two screw sleeves can be achieved by pulling any one of the bidirectional ratchet wrenches, which facilitates operation. It is ensured that the two locking rods move synchronously so that the two clamping heads are stably clamped on the insulator steel cap.

[0043] The clamping head includes two C-shaped connectors, one end of the two connectors is hinged together, and the other end of the two connectors is detachably connected together. Two locking rods are connected between the two clamping heads, and the ends of the two locking rods are connected to the same connector of the clamping head. Connecting heads are provided on the connectors corresponding to the screw rods, and a U-shaped mounting head is provided at the end of the screw rod. The mounting head and the connecting head are inserted and fastened by pins. A number of telescopically movable clamping claws are installed on the clamping head, and the number of clamping claws is determined according to needs. In this embodiment, five clamping claws are evenly installed on each clamping head. An elastic preload is connected between the clamping claws and the clamping head, and an inner clamping force-bearing portion and an outer clamping force-bearing portion are provided at the ends of the clamping claws.

[0044] The claws on the two clamping heads are tilted away from each other and closer to the center of the clamping heads. The tilt angle between the claws and the axis of the clamping heads is 40-60 degrees. In this embodiment, the tilt angle between the claws and the axis of the clamping heads is 45 degrees.

[0045] The elastic preload element is a tension spring. The clamping head and the clamping claw are provided with obliquely arranged mounting holes, each extending through the clamping head. The mounting holes are rectangular in cross-section, and the clamping claw is movably connected to the mounting holes. A slide groove is provided on the clamping claw, and a connecting pin is provided in the slide groove. A positioning pin is connected to the side wall of the mounting hole. The tension spring is connected between the connecting pin and the positioning pin and is installed in the slide groove.

[0046] The claws are radially arranged, with a first notch and a second notch at their ends. The edge of the first notch near the center of the clamping head forms the inner clamping force-bearing portion, while the edge of the second notch near the center of the clamping head forms the outer clamping force-bearing portion. Both the first and second notches are positioned toward the center of the clamping head. The first and second notches are connected end to end. The sidewalls of the first notch include a longitudinal section and a transverse section, with the longitudinal section arranged at an angle. The sidewalls of the second notch include a vertical section and an axial section, with a circular arc transition between the vertical and axial sections.

[0047] The outer wall of the insulator cap is shaped like a stepped shaft, with the step transitioning into a circular arc. The external clamping force-bearing portion of the claw rests against the arc-shaped step. A V-shaped raised ring is provided near the end of the outer wall of the insulator cap, with the external clamping force-bearing portion resting against the raised ring. The insulator is mounted on the insulator cap, with a connecting post at one end and a slot at the other. The connecting post on one adjacent insulator cap fits into the slot on the other cap to achieve connection.

[0048] When replacing insulators on transmission lines, the fixture is installed on the insulator cap, and the two clamping heads can be in any direction. After the clamping is in place, the locking rod is turned to move the two clamping heads toward each other. Under the action of the elastic preload, the end of the clamping claw presses against the outer wall of the insulator cap. When the clamping heads move into place, the inner clamping force-bearing part of the clamping claw on one clamping head presses against the inner outer wall of one insulator cap, and the outer clamping force-bearing part of the clamping claw on the other clamping head presses against the outer wall of the other insulator cap. Under the action of the elastic preload, the clamping claw is clamped on the outer wall of the insulator cap. Because the contact point on the outer wall of the insulator cap with the clamping claw has a slope, the two clamping heads can be locked when they approach each other, preventing axial and radial movement of the entire fixture. After the fixture is installed, the insulator replacement and maintenance between the two clamping heads can be carried out.

[0049] Because the claws are mounted on the mounting head and can be telescopically moved, and an elastic preload is installed between the claws and the mounting head, the fixture can be installed on insulator caps of different sizes and specifications, making it suitable for replacing insulators of different sizes and models. Maintenance workers only need to carry one type of fixture, which helps reduce the number of spare parts, alleviates the burden on operators, and improves maintenance efficiency.

[0050] The force analysis of the claw is as follows: (1) Force analysis of the claws, as shown in the attached Figure 6 , Attachment Figure 7 As shown, FN=F sinα; Ff =FN*μ; where F is the pressure on the claw, FN is the positive pressure between the claw and the clamping head, Ff is the friction force between the claw and the clamping head, and α is the angle between the pressure direction of the claw and the friction surface of the claw (pressure angle), that is, the inclination angle between the claw and the axis of the clamping head.

[0051] (2) Mechanical model of the claw pressure direction and the pressure angle (α) of the claw friction surface: The insulator tension (F) acts on the clamping jaw through the insulator steel cap. When the clamping jaw is under force, the clamping jaw and the clamping jaw must not move to ensure that the clamping jaw will not disengage. When the tension (F) of the clamping jaw is less than the friction force (Ff) between the clamping jaw and the clamping jaw, the clamping jaw will not move. The friction force between the clamping jaw and the clamping jaw has a certain relationship with the pressure angle (α).

[0052] The mathematical model of the force on the claw is as follows: like Figure 8 As shown, the positive pressure between the jaws and the fixture is: FN = F sinα Friction between the jaws and the fixture: Ff = μFN (steel-aluminum static friction coefficient μ = 0.61) = μ F sinα = 0.61 F sinα Mechanical condition for the jaws to not move: F cosα < Ff = 0.61 F sinα That is: F cosα < 0.61 F sinα Tanα>1 / 0.61 Self-locking pressure angle: α > 34.94° Conclusion: When the self-locking pressure angle α> 34.94°, the clamping claw will not move, ensuring that the clamping claw firmly clamps the insulator cap. In this application, α = 45°, which can completely clamp the insulator cap.

[0053] (3) Analysis of the bending force on the jaws, such as Figure 9 、 Figure 10 As shown, bending moment: M = FL; F is the pressure on the claw, M is the bending force on the claw, and L is the length of the lever arm.

[0054] The force analysis of the fixture is as follows: (1) Force analysis of the clamping claw mounting hole of the clamping body, such as Figure 11 、 Figure 12 As shown, the shear force is: Fτ = FL / l; F is the insulator pressure, Fτ is the shear force exerted by the clamping claw on the fixture, L is the length of the insulator pressure arm, and l is the length of the shear force arm exerted by the clamping claw on the fixture.

[0055] (2) Force analysis of the base of the ear of the card (the connection between the card head and the locking rod), such as Figure 13 As shown, F: is the tension of the fixture; FM: is the bending force of the fixture ear; L: is the bending arm length of the fixture ear; M: is the bending moment of the fixture ear; The force state at the base of the ear is bending moment, which is calculated as follows: Bending force of the fixture ear: FM = F / 2; Bending moment of the fixture ear: M = FM L; M = FL / 2.

[0056] Fixture stress check calculation: The clamp is suitable for four types of insulators. Different types of insulators exert different forces on the claws. Different types of insulator caps have different sizes, which results in different claw extension lengths and different stresses on the claws. The longer the claws extend and the greater the force applied, the greater the stress on the claws, which is the ultimate force state of the claws. The larger the insulator cap size, the shorter the claw extension length and the smaller the force applied to the claws. The insulator cap size B is inversely proportional to the stress applied to the claws. The greater the insulator tension, the greater the force applied to the claws. The insulator tension F is directly proportional to the stress applied to the claws. λ = B / F 100%. For an analysis of the force applied to the claws of the four types of insulators, see the attached figure. Figure 14 As can be seen from the figure, when the clamp is gripping the LXY3-210 insulator, the clamping claw is subjected to the greatest tensile force; when the clamp is gripping the LXY1-70 insulator, the clamping claw is extended the longest and is subjected to the greatest bending force. These two situations are the clamping claw's stress limit states.

[0057] Check of tensile stress of jaws The weakest point in the tensile strength of the clamp's jaws is the jaw head.

[0058] The tensile stress analysis and calculation of the jaws are as follows: Tensile stress calculation conditions Number of clamping claws: 3 (considering the irregular shape of the insulator steel cap, resulting in uneven force on the 5 clamping claws) Claw force area: An = 25 × 7.29 = 182.25 mm2 Safety factor of the claw: Considering the importance of the claw parts, the rated tensile force safety factor k1 = 3, The safety factor of tensile strength against failure is k2 = 1.5.

[0059] ① Rated tensile stress of jaw head When grabbing the LXY3-210 insulator, the claws are subjected to the greatest tension.

[0060] Rated maximum load: 60 kN Maximum rated tensile load of jaws: Fn1 = F / 3 = 60 / 3 = 20 kN Maximum rated tensile stress of jaws: σ1 = Fn1 / A = 20000 / 182.25 = 109.74 N / mm2 Maximum tensile stress of the jaws: σ1max = 3 σ1 = 3 × 109.74 = 329.2 N / mm2 ②Destructive tensile stress of the claw head Similarly, when grabbing the LXY3-210 insulator, the claw is subjected to the greatest destructive pulling force.

[0061] Maximum breaking load: 180 kN Jaw breaking tensile load: Fn2 = F / 3 = 180 / 3 = 60 kN Jaw breaking tensile stress: σ2 = Fn2 / A = 60000 / 182.25 = 329.2 N / mm2 Maximum tensile stress of the jaws: σ2max = 1.5 σ2 = 1.5 × 329.2 = 493.8 N / mm2 ③Claw material selection The basis for selecting the jaw material is: yield strength σ0.2 > σ1max = 329.2 N / mm 2 Tensile strength σb > σ2max = 493.8 N / mm 2 Serial number Material Type Material grade <![CDATA[Yield strength σ 0.2 > Tensile strength σb Jaw safety 1 Carbon structural steel Q235 225 375-460 Does not meet requirements 2 High-quality carbon steel 45 355 600 Meet the requirements 3 alloy steel 65Mn 400 735 Meet the requirements The table shows that 45# high-quality carbon steel and 65Mn alloy steel meet the jaw strength requirements. 45# steel has good mechanical properties, a lower price, and reliable heat treatment, while 65Mn steel has better mechanical properties but is more expensive and difficult to heat treat, making it suitable for large parts.

[0062] After comprehensive analysis of the above conditions, we consider using No. 45 high-quality carbon steel to make the claws.

[0063] 3) Check of jaw bending stress The weakest point of the jaws of the adaptive universal closed clamp under bending force is the waist of the jaws.

[0064] When clamping LXY3-210 insulators, the bending stress analysis and calculation of the clamping claws are as follows: Bending stress calculation conditions: Number of clamping claws: 3 When grabbing LXY3-210 insulators: Maximum rated bending force of the jaws: FM1 = F1 sinα / 3 = 60 sin45° / 3 = 14.142 kN Maximum breaking bending force of the jaw: FM2 = F2 sinα / 3 = 180 sin45° / 3 = 42.426 kN When grabbing LXY1-70 insulators: Maximum rated bending force of the jaws: FM3 = F3 sinα / 3 = 25 sin45° / 3 = 5.893 kN Maximum breaking bending force of the jaw: FM4 = F4 sinα / 3 = 75 sin45° / 3 = 17.678 kN Safety factor of jaw bending: Consider the importance of the jaw parts and take Rated bending safety factor kM1 = 3 Failure bending safety factor kM2 = 1.5 Bending cross-sectional area modulus of the jaw head: WX1 = 484.2 mm 3 Bending cross-sectional area modulus of the jaw waist: WX2 = 1777.08 mm 3 ① Rated bending normal stress of jaws When clamping LXY3-210 insulator, the bending moment analysis and calculation of the clamping claw are as follows: a) When grabbing the inner side of the insulator cap: Maximum rated bending moment load of jaws: M1max = FM1 L1 = 14.142 × 4.9 = 69.3 kN.mm Maximum bending normal stress of jaws: σM1=Mmax1 / WX1=69300 / 484.2 = 143.12 N / mm 2 Maximum rated bending stress of jaws: σM1max = 3 σM1 = 3 × 143.12 = 429.36 N / mm 2 b) When grabbing the outside of the insulator cap: Maximum rated bending moment load of jaws: M2max = FM1 L2 = 14.142 × 8.47 = 119.78 kN.mm Maximum bending normal stress of jaws: σM2=Mmax2 / WX2=119780 / 1777.08 = 67.4 N / mm 2 Maximum rated bending stress of jaws: σM2max = 3 σM2 = 3 × 67.4 = 202.21 N / mm 2 When clamping LXY1-70 insulator, the bending moment analysis and calculation of the clamping claw are as follows: a) When grabbing the inner side of the insulator cap: Maximum rated bending moment load of jaws: M3max = FM3 L3 = 5.893 × 25.55 = 150.566 kN.mm Maximum bending normal stress of jaws: σM3=Mmax3 / WX2=150566 / 1777.08 = 84.727 N / mm 2 Maximum rated bending stress of jaws: σM3max = 3 σM3 = 3 × 84.727 = 254.18 N / mm 2 b) When grabbing the outside of the insulator cap: Maximum rated bending moment load of jaws: M4max = FM3 L4 = 5.893 × 8.52 = 50.21 kN.mm Maximum bending normal stress of jaws: σM2=Mmax2 / WX2=50210 / 1777.08 = 28.253 N / mm 2 Maximum rated bending stress of jaws: σM2max = 3 σM2 = 3 × 28.253 = 84.76 N / mm 2 Conclusion: The maximum bending stress of the claw occurs when it grabs the inner side of the LXY3-210 insulator steel cap. σM max1 = 429.36 N / mm 2 ② Normal stress of bending when the jaws break Similarly, the maximum destructive bending normal stress of the clamping claw occurs when it grabs the inner side of the LXY3-210 insulator steel cap.

[0065] Maximum breaking bending moment load of jaws: Mmax2 = FM2 L1 = 42.426 × 4.9 = 207.89 kN.mm Normal stress of bending when jaws fail: σM2=Mmax2 / WX1=207890 / 484.2=429.34 N / mm 2 Maximum breaking bending stress of the jaws: σM max2 = 1.5 σM1 = 1.5 × 143.12 = 644 N / mm 2 Conclusion: The jaws made of 45# high quality carbon steel must be tempered. Yield strength σ0.2 = 450 N / mm 2 > σM max1 = 429.36 N / mm 2 Tensile strength σb = 700 N / mm 2 > σM max2 = 644 N / mm 2 ③Bending shear stress of jaws Similarly, the maximum bending shear stress of the clamping claw occurs when it grabs the inner side of the LXY3-210 insulator steel cap.

[0066] Rated bending shear stress: τmax1 = 3 F1 / S = 3 × 20000 / (25 × 10.5) = 228.57 N / mm 2 Failure bending shear stress: τmax2 = 3 F2 / S = 1.5 × 60000 / (25 × 10.5) = 342.86 N / mm 2 No. 45 high-quality carbon steel: Allowable shear strength τ0.2 = 260 N / mm 2 > τmax1 Yield shear strength τb = 404 N / mm 2 > τmax2 Conclusion: The jaws are made of 45# high quality carbon steel and tempered, and the bending shear stress strength meets the requirements.

[0067] Check of shear stress at mounting hole Closed-type clamps for different insulator types exert varying shear forces on the mounting holes of the clamp, generating varying amounts of shear stress. To determine the maximum shear stress, the shear force on the clamp is greatest when the clamp is extended and the force is high, representing the clamp's ultimate shear stress state. The larger the insulator cap, the shorter the extended jaw length, and the smaller the shear force. The insulator cap size C is inversely proportional to the shear force. The greater the insulator tension, the greater the shear force exerted by the clamp. The insulator tension F is directly proportional to the shear force exerted by the clamp.

[0068] ① Mathematical model of the specific shear force of the inner jaw on the card Fτinside = LF sinα / 31.29 = F sinα[(65-B / 2) / sinα-10.28] / 31.29 = F (65-B / 2-10.28 sin45°) / 31.29 =F(1.845-0.016B) That is: Fτinside=F(1.845-0.016B) As attached Figure 15 As shown in the figure, from the mathematical model diagram of the specific shear force of the inner clamping claw on the clamping, it is found that when clamping the LXY-120 insulator, the maximum specific shear force of the clamping claw on the clamping claw is: Fτin = 7.34 kN ② Mathematical model of the specific shear force of the outer jaw on the card Fτout = LF sinα / 31.29 = F sinα[(65-C / 2) / sinα-22] / 31.29 = F (65-C / 2-22 sin45°) / 31.29 = F (1.58-0.016C) That is: Fτouter = F(1.58-0.016 C) As attached Figure 16 As shown in the figure, from the mathematical model diagram of the specific shear force of the outer clamping claw on the clamping, it is found that when clamping the LXY-120 insulator, the maximum specific shear force of the clamping claw on the clamping claw is: Fτout = 7.05 kN Conclusion: The maximum rated shear force of the claw on the card is when it is grabbing the LXY-120 insulator. Fτ1max = 7.34 kN 2) Maximum rated shear stress at the mounting hole Shear cross-sectional area of the card mounting hole: Sτ = 2 × 34.9 × 15.4 / 2 = 537.46 mm 2 Maximum shear stress of the card mounting hole: τ1 = Fτ1max / Sτ = 7340 / 537.46 = 13.657 N / mm 2 Maximum rated shear stress of the card mounting hole: τ1max = 3 τ1 = 3 × 13.657 = 41 N / mm 2 3) Maximum breaking shear stress at the card's specific mounting hole Maximum breaking shear force of the card mounting hole: Fτ2max = F2 (1.845-0.016B) = 35 (1.845-0.016 × 76) = 22.015 kN Maximum shear stress of the card mounting hole: τ2 = Fτ2max / Sτ = 22015 / 537.46 = 40.96 N / mm 2 τ2max = 1.5τ2 = 1.5 × 40.96 = 61.44 N / mm 2 4) Safety check of shear stress at specific mounting holes ①Card material selection According to the specific material requirements for insulator clamps in the power industry standard DL / T 463-2006 "Insulator clamps for live working", ultra-high strength aluminum alloy LC4 is used, and its corresponding new grade is 7A04.

[0069] Yield strength σ0.2 = 400 N / mm 2 Tensile strength σb = 530 N / mm 2 Allowable shear strength τ0.2 = 230 N / mm 2 Yield shear strength τb = 305 N / mm 2 ② Safety check of shear stress at specific mounting hole locations τb = 160 N / mm 2 > τ2max = 61.44 N / mm 2 τ0.2 = 100 N / mm 2 > τ1max = 41 N / mm 2 Conclusion: The shear strength of the card's specific installation holes is safe.

[0070] Verification of bending stress at the base of concrete ears The weakest point of the card's specific stress strength is the base of the ear, where the stress is in the form of bending stress.

[0071] The bending stress analysis and calculation of the ear base are as follows: Calculation conditions for bending stress at the base of the ear: Number of ears: 2 Force-bearing area at the base of the ear: SM = 60 × 14 = 840 mm 2 Jaw material: LC4 σs = 400 N / mm 2 σb = 530 N / mm 2 Jaw axial tension: FM = 60 / 3 = 20 kN (considering uneven force on the 5 jaws) Safety factor of the claw: Consider the importance of the parts and take Rated safety factor k1=3, damage safety factor k2=1.5 1) Verification of the bending normal stress strength at the base of the ear Bending cross-sectional modulus at the base of the ear: WX = b h2 / 6 = 14×60 2 / 6 = 8400 mm 3 Bending moment at the base of the ear: M1 = FM1 L / 2 = 20 × 30 / 2 = 300 kN / mm Bending positive stress at the base of the ear: σM1 = M1 / WX = 300000 / 8400 = 35.7 N / mm 2 Maximum rated bending normal stress at the base of the ear: σM1max = 3 σM1 = 3 × 35.7 = 107.14 N / mm 2 Bending moment at the base of the ear: M2 = FM2 L / 2 = 60 × 30 / 2 = 900 kN / mm Normal stress of bending at the base of the ear: σM2 = M2 / WX = 900000 / 8400 = 107.14 N / mm 2 Maximum destructive bending normal stress at the base of the ear: σM2max = 3σM2 = 1.5 × 107.14 = 160.714 N / mm 2 Yield strength σ0.2 = 400 N / mm 2 > σM1max = 107.14 N / mm 2 Tensile strength σb = 530 N / mm 2 >σM2max=160.714 N / mm 2 Conclusion: The bending normal stress strength check of the card body ear base is safe.

[0072] 2) Verification of bending shear stress strength at the base of the ear Rated bending shear stress at ear base: τmax1 = 3 F1 / S = 3 × 20,000 / (60 × 14) = 71.43 N / mm 2 Bending shear stress at ear root failure: τmax2 = 1.5 F2 / S = 1.5 × 60000 / (60 × 14) = 107.15 N / mm 2 Allowable shear strength τ0.2 = 230 N / mm 2 > τmax1 = 71.43 N / mm 2 Yield shear strength τb = 305 N / mm 2 > τmax2 = 107.15 N / mm 2 Conclusion: The bending shear stress strength verification of the card concrete ear base is safe.

[0073] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. An adaptive universal fixture for replacing insulators on transmission lines, characterized by: It includes two clamping heads and a locking rod connected between the two clamping heads. The clamping heads are equipped with a plurality of telescopically movable clamping claws. An elastic pre-tightening member is connected between the clamping claws and the clamping heads. The ends of the clamping claws are provided with an inner clamping force-bearing part and an outer clamping force-bearing part.

2. The adaptive universal fixture for replacing insulators of a transmission line according to claim 1, characterized in that: The clamping claws on the two clamping heads are arranged to be inclined in directions away from each other.

3. The adaptive universal fixture for replacing insulators of a transmission line according to claim 2, characterized in that: The inclination angle between the clamping claw and the axis of the clamping head is 40-60 degrees.

4. The adaptive universal fixture for replacing insulators of a transmission line according to claim 1, characterized in that: A first notch and a second notch are provided at the end of the clamping claw. The edge of the first notch close to the center side of the clamping head forms an inner clamping force-bearing part, and the edge of the second notch close to the center side of the clamping head forms an outer clamping force-bearing part.

5. The adaptive universal fixture for replacing insulators of a transmission line according to claim 4, characterized in that: The first notch and the second notch are connected end to end. The side wall of the first notch includes a longitudinal section and a transverse section, and the longitudinal section is inclined. The side wall of the second notch includes a vertical section and an axial section, and there is an arc transition between the vertical section and the axial section.

6. The self-adaptive universal fixture for replacing insulators of a transmission line according to claim 4, characterized in that: The first notch and the second notch are connected end to end. The side wall of the first notch includes a longitudinal section and a transverse section, and the longitudinal section is inclined. The side wall of the second notch is a concave arc structure.

7. The self-adaptive universal fixture for replacing insulators of a transmission line according to claim 1, characterized in that: The elastic preload member is a tension spring.

8. The adaptive universal fixture for replacing insulators of a transmission line according to claim 7, characterized in that: Mounting holes are provided on the clamping head and the clamping claw correspondingly, and the clamping claw is movably plug-in connected to the mounting hole; a slide groove is provided on the clamping claw, a connecting pin is provided in the slide groove, a positioning pin is connected to the side wall of the mounting hole, a tension spring is connected between the connecting pin and the positioning pin, and the tension spring is installed in the slide groove.

9. The adaptive universal fixture for replacing insulators of a transmission line according to any one of claims 1 to 8, characterized in that: The clamping head comprises two C-shaped connecting bodies, one end of the two connecting bodies is hinged together, and the other end of the two connecting bodies is detachably connected together.

10. The adaptive universal fixture for replacing insulators of a transmission line according to any one of claims 1 to 8, characterized in that: The locking rod comprises a screw sleeve and two screw rods. The two screw rods are respectively tightly connected with the two clamping heads. The threads on the two screw rods rotate in opposite directions. The screw sleeve is threadedly connected between the two screw rods.

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