Manual tightening method for 840kN insulator closed fixture and composite tightening lead screw thereof

Abstract

The invention belongs to the technical field of extra-high voltage line maintenance, and particularly relates to a manual tightening method for an 840kN insulator closed fixture and a composite tightening lead screw thereof, which are characterized in that a double-lever reinforcement structure is introduced into a tightening device of the 840kN insulator closed fixture and comprises a first torque-adjusting tension plate and a second torque-adjusting tension plate, the wire tightening lead screw and the pulling plate are connected between the first torque adjusting tension plate and the second torque adjusting tension plate in parallel, and the manual wire tightening lead screw of the 50 kN specification can generate 120 kN tightening force at the two ends of the lead screw connecting piece. The tightening device has the beneficial effects that a double-lever reinforcement structure is adopted on the tightening device of the 840kN insulator closed fixture, so that a 50kN manual trapezoidal lead screw tightening lead screw is balanced with a 120kN insulator tightening force by virtue of the increase of an acting force arm, and the requirement of the tightening operation force of the closed fixture when the 840kN insulator is replaced is met; and the labor intensity of operators is reduced.

Description

Technical Field

[0001] This invention belongs to the field of ultra-high voltage line maintenance technology, and specifically relates to a manual tightening method for 840kN insulator closed clamps and its composite tightening screw. Background Technology

[0002] Currently, the global energy internet, with ultra-high-voltage (UHV) power grids as its backbone, has been elevated to a national strategy. The safe and stable operation of UHV lines is the core task of power grid maintenance. Operating UHV insulators are susceptible to damage due to mechanical loads caused by conductor weight, wind, snow, and ambient temperature variations, as well as factors such as lightning strikes, contamination, and external forces, which can affect the safe and stable operation of the lines. Once UHV lines are in operation, it is very difficult to perform live-line work; therefore, live-line replacement of UHV insulators has become a necessary means to ensure the safe and stable operation of UHV transmission lines.

[0003] Ultra-high voltage (UHV) lines have significantly increased line load and insulator weight compared to UHV lines. 840kN insulators are mainly used in ±1100kV and ±800kV UHVDC transmission lines, with a tightening force of up to 120kN. The associated closed-type clamps are heavy and inconvenient to operate. Currently, the tightening tools on closed-type clamps are mainly hydraulic tensioners and screw tensioners. Both have their drawbacks. Hydraulic tensioners have a large tonnage but are also large and heavy, making them difficult to operate within a limited space. Screw tensioners are easy to operate but have limited tonnage; currently, manual screw tensioners can only achieve a maximum tonnage of 100kN, which cannot meet the requirements for replacing 840kN insulators on UHV lines.

[0004] Chinese invention patent application number 201610657626.9 discloses a universal closed clamp for replacing ultra-high voltage insulators and its usage method. The clamp includes a front clamp, a rear clamp, and a tightening device. The tightening device is located between the front and rear clamps, used to adjust the distance between them during insulator replacement and to apply tension to both clamps. A first bushing is provided in the front clamp, and a second bushing is provided in the rear clamp. The inner surfaces of the first and second bushings respectively match the shape of the insulator steel cap held in the front and rear clamps. The tightening device includes a mechanical screw and a hydraulic transmission mechanism. This hydraulic transmission mechanism requires near-horizontal operation of the hydraulic tightening screw during operation. Because the oil circulation is a closed system, the one-way pump is prone to failure during manual operation, rendering the closed clamp inoperable. Furthermore, the seals in the hydraulic transmission mechanism are prone to aging, resulting in frequent maintenance and repair of the tightening device.

[0005] There is an urgent need for a manual screw tensioner that can meet the tension requirements of 840KN insulators, replacing the less reliable hydraulic tensioning device, while also reducing the weight of the tensioning device itself, making it easier to carry and use. Summary of the Invention

[0006] The purpose of this invention is to provide a manual tightening method for 840kN insulator closed clamps and its composite tightening screw, which overcomes the shortcomings of the prior art. The tightening device adopts a double lever force-enhancing structure, which enables the 50kN manual screw tensioner to achieve a balance with the tightening force required for operation of 120 kN through the force-enhancing lever arm, thus meeting the operation requirements of closed clamps when replacing 840kN insulators in the operation and maintenance of UHV lines.

[0007] To achieve the above objectives, the present invention provides the following technical solution: One technical solution: A manual tightening method for an 840kN insulator closed clamp, characterized by introducing a double-lever force-enhancing structure into the tightening device of the 840kN insulator closed clamp. The double-lever force-enhancing structure includes a torque-adjusting tension plate one and a torque-adjusting tension plate two, and a tensioning screw and a pull plate connected parallel to the torque-adjusting tension plate one and the torque-adjusting tension plate two. The hinge points of the tensioning screw and the pull plate on the torque-adjusting tension plate one correspond to screw hole one and pull plate hole one, respectively. The torque-adjusting tension plate one also has a hinge hole for installing a screw connector one. The centerline of the screw connector one intersects the line connecting screw hole one and pull plate hole one on the torque-adjusting tension plate one at the intersection point. The distance between screw hole one and the intersection point is l, and the distance between the intersection point and the pull plate hole is m, then l / m≥2; the positions of the three openings on the torque-adjusting tension plate two are symmetrical to the positions of the three openings on the torque-adjusting tension plate one. A manual tensioning screw with a kN specification can generate a tightening force of 120 kN at both ends of the screw connector.

[0008] Furthermore, the pull plate is provided with weight reduction holes, and the pull plate is not limited to the stacking of multiple plates.

[0009] Furthermore, the tensioning screw is a trapezoidal screw type, with an adjustment distance of 400-700mm.

[0010] Furthermore, the tensioning screw is adjusted to its maximum length before the device operates on the tower, and the minimum adjustment length of the tensioning screw is less than or equal to the length of the pull plate.

[0011] Furthermore, the 840kN insulator is an 840kN glass insulator or an 840kN porcelain insulator.

[0012] Furthermore, the maximum value of l / m is no more than 3.

[0013] Technical Solution Two: A composite tensioning screw, characterized in that it includes a torque adjusting plate one, a torque adjusting plate two, a tensioning screw, a pull plate, a screw connector one, and a screw connector two. The screw connector one is connected to the torque adjusting plate one, and the screw connector two is connected to the torque adjusting plate two. The torque adjusting plate one and the torque adjusting plate two are connected in parallel with the tensioning screw and the pull plate, and each connection point is a hinge structure. The hinge points of the tensioning screw and the pull plate on the torque adjusting plate one correspond to the screw hole one and the pull plate hole one, respectively. The centerline of the screw connector one is extended and intersects the line connecting the screw hole one and the pull plate hole one on the torque adjusting plate one. The distance between the screw hole one and the intersection point is l, and the distance between the intersection point and the pull plate hole one is m, then l / m≥2. The screw connector one and the screw connector two are symmetrical in left and right positions.

[0014] Furthermore, at least one ball bearing adjusting sleeve is provided on both the lead screw connector one and the lead screw connector two.

[0015] Furthermore, the composite tensioning screw is equipped with an 840KN insulator closed clamp, and the two sets of composite tensioning screws are connected to the front clamp and the rear clamp respectively.

[0016] Furthermore, the tensioning screw is a trapezoidal screw, equipped with a ratchet wrench.

[0017] Compared with the prior art, the beneficial effects of the present invention are: A double-lever force-increasing structure is adopted on the tightening device of the 840kN insulator closed clamp. The 50kN manual trapezoidal screw tightening screw achieves balance with the 120 kN insulator tightening force by increasing the force arm, thereby meeting the tightening operation force requirements of the closed clamp when replacing the 840kN insulator. It can replace the less reliable hydraulic tightening device, while reducing the weight of the tightening device itself, making it easier to carry and use. This allows the manual tightening screw to be applied to the maintenance of insulators on 120 kN ultra-high voltage power lines, improving the operational efficiency and reliability of tower work and reducing the labor intensity of operators. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the double-lever force-enhancing structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the tightened state of the double-lever force-enhancing structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of an embodiment of the composite tightening screw of the present invention; Figure 4 This is a schematic diagram illustrating the application of the composite tightening screw in an 840kN insulator closed clamp according to an embodiment of the present invention; Figure 5 This is a schematic diagram of a torque-adjusting tension plate in an embodiment of the present invention; Figure 6 This is a schematic diagram of the tensioning screw structure in an embodiment of the present invention; Figure 7 This is a schematic diagram of the ball adjusting sleeve structure in an embodiment of the present invention; In the diagram: 1-Torque Adjusting Plate 1, 2-Torque Adjusting Plate 2, 3-Tightening Screw, 4-Pull Plate, 5-Screw Hole 1, 6-Pull Plate Hole 1, 7-Screw Connector 1, 7'-Screw Connector 2, 8-Hinge Hole, 9-Weight Reduction Hole, 10-Composite Tightening Screw, 11-Front Clamp, 12-Rear Clamp, 13-Insulator String, 14-Ball Adjustment Sleeve, 15-Outer Tube, 16-Inner Tube, 17-Tightening Nut, 18-Ball, 19-Ratchet Wrench, 20-Outer Sheath, 21-Inner Sleeve, 22-Thrust Ball Bearing, 23-Screw, 24-Telescopic Sleeve, 25-Anti-reverse Nut. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the specific embodiments used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some embodiments of the present invention. For those skilled in the art, other specific embodiments can be obtained based on these specific embodiments without creative effort.

[0021] The components of the embodiments of the invention described and shown in the specific embodiments herein can be arranged and designed in countless different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the specific embodiments is not intended to limit the scope of the claimed invention, but merely to illustrate the invention. See Figure 1-2This is a schematic diagram of the double-lever force-enhancing structure in an embodiment of the manual tightening method for an 840kN insulator closed clamp according to the present invention. The present invention introduces a double-lever force-enhancing structure into the tightening device of the 840kN insulator closed clamp. The double-lever force-enhancing structure includes a torque-adjusting tension plate 1 and a torque-adjusting tension plate 2, and a tensioning screw 3 and a pull plate 4 connected in parallel between the torque-adjusting tension plate 1 and the torque-adjusting tension plate 2. The hinge points of the tensioning screw 3 and the pull plate 4 on the torque-adjusting tension plate 1 correspond to screw hole 5 and pull plate hole 6, respectively. The torque-adjusting tension plate 1... 1 is also provided with a hinge hole 8 for installing the lead screw connector 7. The center line of the lead screw connector 7 is extended and intersects the line connecting the lead screw hole 5 and the pull plate hole 6 on the torque adjustment plate 1 at the intersection point A. The distance between the lead screw hole 5 and the intersection point A is l, and the distance between the intersection point A and the pull plate hole 6 is m. Then l / m≥2. The positions of the three openings on the torque adjustment plate 2 are symmetrical with the positions of the three openings (i.e., lead screw hole 5, pull plate hole 6 and hinge hole 8) on the torque adjustment plate 1. The tightening force of the tensioning screw 3 is amplified by at least three times, so that the 50 kN manual tensioning screw 3 can generate a tightening force of more than 120 kN at both ends of the lead screw connector 7 and the lead screw connector 2 7'.

[0022] The pull plate 4 has weight-reducing holes 9 to reduce its own weight. At the same time, the pull plate 4 is not limited to the stacking of multiple plates to achieve a sufficient cross-sectional area and achieve a sufficiently large tensile strength.

[0023] The tensioning screw 3 is a trapezoidal screw tensioner with an adjustment distance of 400-700mm. The tensioning screw 3 should be adjusted to its maximum length before operation on the tower. The minimum adjustment length of the tensioning screw 3 should be less than or equal to the length of the pull plate 4. To ensure adequate operating space, the maximum length l / m should not exceed 3.

[0024] This invention applies to 840kN insulators, including 840kN glass insulators or 840kN porcelain insulators.

[0025] See Figure 3-7The present invention provides a composite tensioning screw, comprising a torque adjusting plate 1, a torque adjusting plate 2, a tensioning screw 3, a pull plate 4, a screw connector 7, and a screw connector 7'. The screw connector 7 is hinged to the torque adjusting plate 1, and the screw connector 7' is hinged to the torque adjusting plate 22. The tensioning screw 3 and the pull plate 4 are connected in parallel between the torque adjusting plate 1 and the torque adjusting plate 22. All connection points are hinged structures to avoid excessive operating resistance during operation. The tensioning screw 3 and the pull plate 4 are hinged on the torque adjusting plate 1. Points 5 and 6 correspond to the lead screw hole and the pull plate hole, respectively. The torque adjusting plate 1 also has a hinge hole 8 for installing the lead screw connector 7. The centerline of the lead screw connector 7 intersects the line connecting the lead screw hole 5 and the pull plate hole 6 on the torque adjusting plate 1 at point A. The distance between the lead screw hole 5 and point A is l, and the distance between point A and the pull plate hole 6 is m. Therefore, l / m ≥ 2. When l / m = 2, the torque adjusting plate 1, the torque adjusting plate 22, the tensioning lead screw 3, and the pull plate 4 form a double-lever force-increasing structure. The lead screw connector 27' connects to the torque adjusting plate 22. The lead screw connectors 17 and 27' are symmetrical in their left and right positions. The composite tensioning screw 10 is matched with an 840KN insulator. When in use, the two sets of composite tensioning screws 10 are connected to the front clamp 11 and the rear clamp 12 respectively to form a closed clamp, which clamps the insulator string 13. The two tensioning screws 3 are operated until the insulator string 13 is loosened, and then the insulator string can be replaced.

[0026] Depending on the installation position, the structure and length of the screw connector 1 7 and screw connector 2 7' may vary slightly. Both ends are provided with forks and bolt holes for connection with corresponding components. To further improve the length of the adjustment range, a ball bearing adjustment sleeve 14 can be provided in screw connector 1 7, including an outer tube 15, an inner tube 16 and a tightening nut 17. A ball bearing 18 is provided between the tightening nut 17 and the outer tube 15, so that the tightening nut 17 and the outer tube 15 can rotate relative to each other, but cannot move along the axis. The tightening nut 17 is engaged with the thread on the outer surface of the inner tube 16. When the tightening nut 17 is rotated, the inner tube 16 can retract relative to the outer tube 15, which plays the role of adjusting the overall length of the composite tightening screw. When the composite tightening screw is not under force, the tightening nut 17 can be operated by hand. When the tightening nut 17 is working on the tower, the friction is too great, so it cannot be operated by hand. Only the tensioning screw 3 can be operated to adjust the length.

[0027] The tensioning screw 3 is a trapezoidal screw that can achieve self-locking. Its structure includes a ratchet wrench 19, an outer sleeve 20, an inner sleeve 21, a thrust ball bearing 22, a screw 23, a telescopic sleeve 24, and a lock nut 25. The outer sleeve 20 is fixedly connected to the telescopic sleeve 24 with screws. The thrust ball bearing 22 is located between the outer sleeve 20 and the inner sleeve 21. The ratchet wrench 19 is fixedly connected to the inner sleeve 21. The inner sleeve 21 engages with the threads on the outer surface of the screw 23. The lock nut 25 is located at the end of the screw 23 to limit its maximum stroke. By operating the ratchet wrench 19, the screw 23 can move relative to the telescopic sleeve 24 along the axis, adjusting the length of the tensioning screw 3 to complete the tightening operation.

[0028] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manual tightening method for an 840kN insulator closed-type clamp, characterized in that, A double-lever force-enhancing structure is introduced into the tightening device of the closed clamp for 840kN insulators. The double-lever force-enhancing structure includes a torque-adjusting tension plate one and a torque-adjusting tension plate two, as well as a tensioning screw and a pull plate connected in parallel between the torque-adjusting tension plate one and the torque-adjusting tension plate two. The hinge points of the tensioning screw and the pull plate on the torque-adjusting tension plate one correspond to the screw hole one and the pull plate hole one, respectively. The torque-adjusting tension plate one is also provided with a hinge hole for installing the screw connector one. The center line of the screw connector one intersects the line connecting the screw hole one and the pull plate hole one on the torque-adjusting tension plate one at the intersection point. The distance between the screw hole one and the intersection point is l, and the distance between the intersection point and the pull plate hole one is m, so l / m≥2. The positions of the three openings on the torque-adjusting tension plate two are symmetrical with the positions of the three openings on the torque-adjusting tension plate one. A 50 kN manual tensioning screw can generate a tightening force of 120 kN at both ends of the screw connector.

2. The manual tightening method for an 840kN insulator closed clamp according to claim 1, characterized in that, The pull plate has weight-reducing holes, and the pull plate is not limited to the stacking of multiple plates.

3. The manual tightening method for an 840kN insulator closed clamp according to claim 1, characterized in that, The tensioning screw is a trapezoidal screw type, with an adjustment distance of 400-700mm.

4. The manual tightening method for an 840kN insulator closed clamp according to claim 1, characterized in that, The tensioning screw is adjusted to its maximum length before the device operates on the tower, and the minimum adjustment length of the tensioning screw is less than or equal to the length of the pull plate.

5. The manual tightening method for an 840kN insulator closed clamp according to claim 1, characterized in that, The 840kN insulator is either an 840kN glass insulator or an 840kN porcelain insulator.

6. The manual tightening method for an 840kN insulator closed clamp according to claim 1, characterized in that, The maximum value of l / m is no more than 3.

7. A composite tensioning screw, characterized in that, The system includes a torque adjusting plate 1, a torque adjusting plate 2, a tensioning screw, a pull plate, a screw connector 1, and a screw connector 2. Screw connector 1 is connected to torque adjusting plate 1, and screw connector 2 is connected to torque adjusting plate 2. The tensioning screw and pull plate are connected in parallel between torque adjusting plate 1 and torque adjusting plate 2, and all connection points are hinged structures. The hinge points of the tensioning screw and pull plate on torque adjusting plate 1 correspond to screw hole 1 and pull plate hole 1, respectively. The centerline of screw connector 1 is extended and intersects the line connecting screw hole 1 and pull plate hole 1 on torque adjusting plate 1. The distance between screw hole 1 and the intersection point is l, and the distance between the intersection point and pull plate hole 1 is m. Therefore, l / m≥2. Screw connector 1 and screw connector 2 are symmetrical in left and right positions.

8. A composite tensioning screw according to claim 7, characterized in that, At least one ball bearing adjusting sleeve is provided on both the lead screw connector one and the lead screw connector two.

9. A composite tensioning screw according to claim 7, characterized in that, The composite tightening screw is equipped with an 840KN insulator. The two sets of composite tightening screws are connected to the front clamp and the rear clamp respectively to form a closed clamp.

10. A composite tensioning screw according to claim 7, characterized in that, The tensioning screw is a trapezoidal screw and is equipped with a ratchet wrench.

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