Guided wave excitation device for detecting damage state of grounding material of transmission tower

Abstract

The invention belongs to the technical field of nondestructive testing, and relates to a guided wave excitation device for detecting the damage state of a grounding material of a transmission tower. The device comprises a probe module and a PVDF flexible piezoelectric plate which are arranged at the two ends of a grounding rod respectively, the probe module comprises a mounting base, a connecting shell, a probe, a sliding cover and a driving assembly, the connecting shell is fixed to the mounting base, the upper end face of the connecting shell is in a circular arc shape, the sliding cover is in sealed sliding connection with the circular arc part of the connecting shell, and the probe is mounted on the sliding cover. According to the device, the inclination angle of the probe can be accurately adjusted, and the sliding plate moves relative to the fixed plate, so that the position of the motor relative to the hinge shaft is adjusted, and the position of the adjustable angle interval of the probe is adjusted. The connecting ring rotates relative to the eccentric wheel, the distance between the protruding block and the motor is adjusted, the radius of the motion trail M of the protruding block is adjusted, and then the size of the adjustable angle interval of the probe is adjusted.

Description

Technical Field

[0001] The invention belongs to the technical field of nondestructive testing and relates to a waveguide excitation device for detecting the damage state of grounding materials of a power transmission tower. Background Art

[0002] Damage to the grounding material of the transmission tower will reduce the lightning resistance of the transmission line, increase the lightning trip rate, pose a safety hazard, and affect the reliability of power supply. It will also increase the grounding resistance and affect the dispersion characteristics of the tower grounding device. Therefore, it is necessary to promptly detect the damage status of the grounding material of the transmission tower for maintenance.

[0003] A patent document with publication number CN115266947A discloses an ultrasonic longitudinal waveguide excitation device for polyethylene gas pipelines, including a probe and a wedge. The wedge is provided with a cavity filled with coupling agent. The wedge is slidably matched with a sliding cover that blocks the opening of the cavity. The probe is mounted on the slider and one end is inserted into the cavity. The device can adjust the tilt direction of the probe to change the oblique incident angle of the probe, and can also adjust the distance between the probe and the pipeline, so as to achieve the adjustment of multiple waveguide modes to improve the detection efficiency and ensure the safe operation of the pipeline. However, when adjusting the tilt angle of the probe in the device, it cannot be accurately adjusted to the required range, and the adjustment angle amplitude is fixed and cannot be adjusted as needed.

[0004] In order to solve the above problems, the present invention proposes a waveguide excitation device for detecting the damage status of grounding materials of a transmission tower. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the present invention proposes a waveguide excitation device for detecting the damage status of grounding materials of a transmission tower.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] The invention discloses a waveguide excitation device for detecting the damaged state of grounding material of a power transmission tower, comprising a probe module and a PVDF flexible piezoelectric sheet respectively arranged at two ends of a grounding rod, wherein the probe module comprises a mounting seat, a connecting shell, a probe, a sliding cover and a driving assembly; the connecting shell is fixed on the mounting seat, the upper end surface of the connecting shell is an arc portion, the sliding cover is sealingly and slidingly connected with the arc portion of the connecting shell, and the probe is mounted on the sliding cover; the driving assembly comprises a connecting rod and an eccentric wheel, a sliding plate is slidingly installed on the mounting seat in an upper limit position, the eccentric wheel is rotatably installed on the sliding plate, a convex block is fixedly connected to the eccentric wheel, a waist-shaped groove is provided on the connecting rod, and the convex block is movably arranged in the waist-shaped groove; the eccentric wheel rotates, and the sliding cover is driven to swing through the connecting rod, thereby driving the probe to swing, so as to adjust the incident angle of the probe.

[0008] Furthermore, the eccentric wheel is detachably fixedly connected with a connecting ring, the connecting ring is coaxially arranged with the eccentric wheel, and the protrusion is fixed on the connecting ring.

[0009] Furthermore, the mounting base includes a fixing plate and a V-shaped plate; the bottom surface of the V-shaped plate cooperates with the outer wall of the grounding rod, the fixing plate is fixedly mounted on the top surface of the V-shaped plate, and the connecting shell is fixed on the top surface of the V-shaped plate.

[0010] Furthermore, the probe and the sliding cover are threadedly connected; the connecting shell, the sliding cover, the V-shaped plate and the grounding rod form a coupling agent cavity; the output end of the probe extends into the coupling agent cavity and points to the axis of the grounding rod.

[0011] Furthermore, two rubber blocks are arranged at the bottom of the V-shaped plate to increase the sealing between the V-shaped plate and the grounding rod.

[0012] Furthermore, a square groove is provided on the fixing plate. When in use, the fixing belt is passed through the square groove, and the two ends of the fixing belt are fixed, and then the mounting base is installed on the grounding rod.

[0013] Furthermore, an angle line is provided on the connecting shell, and the angle line is used to indicate the tilt angle of the probe.

[0014] Furthermore, the sliding plate is connected to the fixed plate in a limited sliding manner; a threaded rod is rotatably installed on the fixed plate, a connecting block is threadedly connected to the threaded rod, and the connecting block is fixedly connected to the sliding plate.

[0015] Furthermore, adjustment scale lines are arranged on the fixing plate at positions corresponding to the connecting blocks.

[0016] Furthermore, a threaded hole is provided on the connecting ring, and the fastening screw is screwed into the threaded hole and abuts against the eccentric wheel, thereby fixing the eccentric wheel and the connecting ring; the spacing between the protrusion and the motor is adjusted by matching the fastening screw with different positions of the eccentric wheel.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. When the ground rod rotates in the area near the tangent point M of the motion trajectory of the connecting rod and the bump, the connecting rod rotates slowly, so the tilt angle of the probe in the corresponding interval can be accurately adjusted.

[0019] 2. Move the sliding plate relative to the fixed plate, thereby adjusting the position of the motor relative to the hinge shaft and adjusting the position of the adjustable angle range of the probe.

[0020] 3. Make the connecting ring rotate relative to the eccentric wheel, adjust the distance between the protrusion and the motor, adjust the radius of the motion trajectory M of the protrusion, and then adjust the size of the adjustable angle range of the probe.

[0021] 4. When the probe module is installed on the ground rod, both sides of the V-shaped plate are fitted with the ground rod, so that the probe can automatically point to the axis of the ground rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 The present invention Figure 1 A magnified view of part A;

[0024] Figure 3 It is a structural schematic diagram of the mounting frame in the present invention;

[0025] Figure 4 is a cross-sectional view of the connecting shell in the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the V-shaped plate in the present invention;

[0027] Figure 6 It is a structural schematic diagram of the connecting rod in the present invention;

[0028] Figure 7 It is a structural schematic diagram of the adjustment handle in the present invention;

[0029] Figure 8 It is a schematic diagram of the connection between the fixed plate and the sliding plate in the present invention;

[0030] Fig. 9 It is a schematic diagram of the state after the sliding plate moves a certain distance relative to the fixed plate in the present invention;

[0031] Fig.10 It is a schematic diagram of the connection between the eccentric wheel and the connecting ring in the present invention;

[0032] Fig.11 It is a schematic diagram of the motion of the projection in the present invention.

[0033] In the figure: 1. ground rod; 2. fixed plate; 3. sliding plate; 4. PVDF flexible piezoelectric sheet; 5. fixing belt; 6. mounting hole; 7. motor; 8. eccentric wheel; 9. connecting ring; 10. connecting rod; 11. bump; 12. waist groove; 13. probe; 14. sliding cover; 15. square groove; 16. V-shaped plate; 17. connecting shell; 18. angle line; 19. adjusting handle; 20. liquid coupling agent cavity; 21. fixing block; 22. rubber block; 23. connecting block; 24. adjustment scale line; 25. sealing plug; 26. hinge shaft; 27. fastening screw. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] like Figure 1-Figure 11 The guided wave excitation device shown is used for detecting the damage status of the grounding material of the transmission tower.

[0036] Embodiment 1: The technical solution adopted by the present invention is as follows: The waveguide excitation device for detecting the damage status of the grounding material of the transmission tower includes a probe module and a PVDF flexible piezoelectric sheet 4. The probe module and the PVDF flexible piezoelectric sheet 4 are respectively installed at both ends of the grounding rod 1. The PVDF flexible piezoelectric sheet 4 is surrounded and attached to the outer wall of the grounding rod 1. The waveguide emitted by the probe module is based on the oblique incidence of the body wave, which excites the longitudinal waveguide of a specific mode to propagate axially along the grounding rod 1. The PVDF flexible piezoelectric sheet 4 receives the waveguide signal at the other end, and after the preamplifier gain, the waveguide signal is analyzed and processed using an oscilloscope and a computer.

[0037] The probe module includes a mounting base, a probe 13, a connecting shell 17, a sliding cover 14 and a driving assembly.

[0038] There are multiple mounting seats, which are connected in series through a fixing belt 5 and sleeved on the grounding rod 1. Each mounting seat includes a fixing plate 2 and a V-shaped plate 16. The bottom surface of the V-shaped plate 16 cooperates with the grounding rod 1. The fixing plate 2 is fixedly mounted on the top surface of the V-shaped plate 16.

[0039] A square groove 15 is provided on the fixing plate 2. A plurality of mounting holes 6 are provided on the fixing belt 5 along the length direction. When the mounting seat is installed on the grounding rod 1, the plurality of mounting seats are connected together by the fixing belt 5 and sleeved on the grounding rod 1. The fixing belt 5 passes through the square groove 15, and then the two ends of the fixing belt 5 are fixedly connected by bolts, so that the mounting seat is fixed to the grounding rod 1. By making the bolts cooperate with different mounting holes 6, the fixing belt 5 can adapt to grounding rods 1 with different outer diameters. In this embodiment, two square grooves 15 are provided on the fixing plate 2, and the fixing belt 5 has two, and the two fixing belts 5 correspond to the two square grooves 15 one by one, and the fixing belt 5 passes through the corresponding square grooves 15. The mounting seat can be better fixed by the two fixing belts 5.

[0040] When the mounting base is fixed on the ground rod 1 , the axis of the ground rod 1 is parallel to the ridge line of the V-shaped plate 16 .

[0041] A connection shell 17 is fixedly mounted on the top surface of each V-shaped plate 16, and the upper part of the connection shell 17 is an arc portion, and the axis of the arc portion is perpendicular to the axis of the grounding rod 1. The arc portion of the connection shell 17 is provided with an opening. An outlet is provided on the side of the connection shell 17 close to the grounding rod 1, and the outlet passes through the V-shaped plate 16. The sliding cover 14 is adapted to the arc portion of the connection shell 17, and the sliding cover 14 and the arc portion of the connection shell 17 are sealed and slidably matched. The sliding cover 14 blocks the opening of the connection shell 17. A threaded hole is provided on the sliding cover 14, and a probe 13 is threadedly connected to each sliding cover 14 through the threaded hole.

[0042] The connecting shell 17, the sliding cover 14, the V-shaped plate 16 and the grounding rod 1 form a coupling agent cavity 20. The output end of the probe 13 passes through the opening of the connecting shell 17 and extends into the coupling agent cavity 20 and points to the axis of the grounding rod 1. By twisting the probe 13, the depth of the output end of the probe 13 extending into the coupling agent cavity 20 can be adjusted to adjust the distance between the output end of the probe 13 and the grounding rod 1. The sliding cover 14 is slid relative to the connecting shell 17 to adjust the angle between the probe 13 and the axis of the grounding rod 1, thereby adjusting the incident angle of the probe 13. By adjusting the incident angle and screw-in depth of the probe 13, ultrasonic longitudinal guided waves of different modes are excited to meet various requirements for guided wave detection of the grounding rod 1.

[0043] The connecting shell 17 is provided with a liquid filling port, and a sealing plug 25 is provided at the liquid filling port. After the mounting base is mounted on the grounding rod 1, the coupling agent is injected into the coupling agent cavity 20 through the liquid filling port.

[0044] like Figure 5 As shown, rubber blocks 22 are fixedly installed on both sides of the bottom surface of the V-shaped plate 16 to increase the sealing between the V-shaped plate 16 and the outer surface of the grounding rod 1 to prevent the coupling agent from flowing out from the gap between the V-shaped plate 16 and the grounding rod 1.

[0045] An angle line 18 is provided on the connection shell 17 , and the angle line 18 is used to indicate the tilt angle of the probe 13 , that is, the incident angle of the probe 13 .

[0046] The driving assembly is used to drive the sliding cover 14 to slide relative to the connecting shell 17. The driving assembly includes an eccentric wheel 8 and a connecting rod 10. A fixing block 21 is fixedly mounted on the fixing plate 2, and one end of the connecting rod 10 is hinged to the fixing block 21 through a hinge shaft 26. The axis of the hinge shaft 26 coincides with the axis of the arc portion of the connecting shell 17. A waist-shaped groove 12 is provided on the connecting rod 10 along the length direction, and a protrusion 11 is slidably provided in the waist-shaped groove 12. The connecting rod 10 is fixedly connected to the sliding cover 14.

[0047] The upper limit sliding of the fixed plate 2 is provided with a sliding plate 3. The moving direction of the sliding plate 3 relative to the fixed plate 2 is parallel to the axial direction of the grounding rod 1. Specifically, a threaded rod is rotatably connected to the fixed plate 2, and a connecting block 23 is threadedly connected to the threaded rod, and the connecting block 23 is fixedly connected to the sliding plate 3. An adjustment handle 19 is fixed to one end of the threaded rod. The threaded rod rotates, so that the connecting block 23 moves left and right, and then the sliding plate 3 moves left and right along the fixed plate 2.

[0048] The sliding plate 3 is fixedly mounted with a motor 7, and the motor shaft of the motor 7 is eccentrically fixedly connected to the eccentric wheel 8. The outer circumference of the eccentric wheel 8 is coaxially fixedly sleeved with a connecting ring 9. The bump 11 is fixed on the connecting ring 9. The eccentric wheel 8 rotates eccentrically, driving the connecting rod 10 to swing, the connecting rod 10 drives the sliding cover 14 to swing, and the sliding cover 14 drives the probe 13 to swing, thereby adjusting the tilt angle of the probe 13.

[0049] Working principle: When in use, first fix the mounting base to the ground rod 1 to be detected. Specifically, according to the outer diameter of the ground rod 1, a suitable number of mounting bases can be connected in series through the fixing belt 5. Then the probe module is sleeved on the ground rod 1, and the fixing belt 5 is tightened so that both sides of the bottom surface of the V-shaped plate 16 are in contact with the ground rod 1. At this time, the ridge line of the V-shaped plate 16 is parallel to the axis of the ground rod 1, and the output end of the probe 13 points to the axis of the ground rod 1. Then use bolts to fix and connect the two ends of the fixing belt 5. By matching the bolts with different mounting holes 6, it can adapt to ground rods 1 with different outer diameters, thereby improving the applicability of the device. When the probe module is installed on ground rods 1 with different outer diameters, the output end of the probe 13 automatically points to the axis of the ground rod 1 to improve the accuracy and reliability of the detection results of the probe 13, and prevent the probe 13 from being misaligned with the axis of the axis of the ground rod 1, affecting the detection results. At this time, the axis of the ground rod 1, the ridge line of the V-shaped plate 16, and the axis of the probe 13 are on the same plane.

[0050] The coupling agent cavity 20 is sealed by the outer wall of the ground rod 1. The sealing plug 25 is opened, and then the coupling agent is added into the connection block 23 through the liquid filling port, and then the sealing plug 25 is covered.

[0051] Then, the PVDF flexible piezoelectric sheet 4 is installed on the other end of the ground rod 1 , and the PVDF flexible piezoelectric sheet 4 surrounds and fits on the outer wall of the ground rod 1 .

[0052] Then the grounding rod 1 is tested. During the testing process, when the distance between the probe 13 and the grounding rod 1 needs to be adjusted, the probe 13 is twisted, and the probe 13 moves along the sliding cover 14 toward the axis direction of the grounding rod 1 or away from the axis direction of the grounding rod 1.

[0053] When the tilt angle of the probe 13 needs to be adjusted, the motor 7 is started, the motor 7 drives the eccentric wheel 8 to rotate, the eccentric wheel 8 drives the connecting ring 9 to rotate, the protrusion 11 rotates around the motor 7, the connecting rod 10, the sliding cover 14 and the probe 13 all rotate around the hinge shaft 26, thereby adjusting the tilt angle of the probe 13.

[0054] Specifically, Fig.11 As shown, A is the axis of the motor 7, B is the axis of the bump 11, C is the axis of the hinge shaft 26, M is the motion trajectory of the bump 11, and line CD is parallel to the axis of the grounding rod 1. Then, the swing amplitude of the connecting rod 10 is 2∠ACB, and the swing range of the connecting rod 10 is from (∠ACD-∠ACB) to (∠ACD+∠ACB). As the bump 11 rotates around the motor 7, when ∠ABC is equal to 90 degrees, that is, when BC is tangent to the motion trajectory M of the bump 11, the speed of the connecting rod 10 rotating around the hinge shaft 26 is the slowest, and when the bump 11 is in the area near the tangent point, the speed of the connecting rod 10 rotating around the hinge shaft 26 is slow. Therefore, when the bump 11 moves in the area near the tangent point, the swing angle of the connecting rod 10 can be accurately controlled, and then the tilt angle of the probe 13 can be accurately adjusted within the corresponding range. In this embodiment, the tilt angle of the connecting rod 10 is consistent with the tilt angle of the probe 13.

[0055] Therefore, by adjusting the intersection position of BC and the motion trajectory M of the protrusion 11, the angle range that the probe 13 needs to be precisely adjusted can be adjusted.

[0056] When it is necessary to adjust the adjustable range of the probe 13, the adjusting handle 19 is rotated to move the sliding plate 3 relative to the fixed plate 2, thereby changing the position of the motor 7 relative to the hinge shaft 26, that is, changing the size of ∠ACD. Therefore, the swinging area of ​​the connecting rod 10 is changed, and the position of the adjustable angle range of the probe 13 is changed. At the same time, the position of the intersection point of BC and the motion trajectory M of the protrusion 11 is changed, and the position of the precisely adjustable range of the probe 13 is changed.

[0057] An adjustment scale line 24 is provided on the fixing plate 2 at a position corresponding to the connection block 23. The adjustment scale line 24 is used to display the position of the motor 7 relative to the hinge shaft 26, that is, to display the size of ∠ACD. By observing the scale on the adjustment scale line 24 pointing to the connection block 23, the size of ∠ACD can be obtained.

[0058] Embodiment 2: This embodiment is an improvement based on embodiment 1.

[0059] The eccentric wheel 8 and the connecting ring 9 are detachably fixedly connected by a fastening screw 27. Specifically, a threaded hole is provided on the connecting ring 9, and the fastening screw 27 is screwed into the threaded hole and abuts against the eccentric wheel 8, thereby fixing the eccentric wheel 8 and the connecting ring 9. By cooperating the fastening screw 27 with different positions of the eccentric wheel 8, the spacing between the protrusion 11 and the motor 7 is adjusted, and then the rotation radius of the protrusion 11 is adjusted, so that the radius of the motion trajectory M of the protrusion 11 increases or decreases. If the radius of the motion trajectory M of the protrusion 11 increases, ∠ACB increases, the swing amplitude of the connecting rod 10 increases, and the adjustable angle range of the probe 13 becomes larger. If the radius of the motion trajectory M of the protrusion 11 decreases, ∠ACB decreases, the swing amplitude of the connecting rod 10 decreases, and the adjustable angle range of the probe 13 becomes smaller.

[0060] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A guided wave excitation device for detecting the damage state of grounding materials of a power transmission tower, comprising a probe module and a PVDF flexible piezoelectric sheet (4) respectively arranged at two ends of a grounding rod (1), Features: The probe module comprises a mounting seat, a connecting shell (17), a probe (13), a sliding cover (14) and a driving assembly; the connecting shell (17) is fixed on the mounting seat, the upper end surface of the connecting shell (17) is a circular arc portion, the sliding cover (14) is sealingly and slidably connected to the circular arc portion of the connecting shell (17), and the probe (13) is mounted on the sliding cover (14); the driving assembly comprises a connecting rod (10) and an eccentric wheel (8); a sliding plate (3) is slidably mounted on the mounting seat in an upper limit position, the eccentric wheel (8) is rotatably mounted on the sliding plate (3), the eccentric wheel (8) is fixedly connected with a protrusion (11), a waist-shaped groove (12) is provided on the connecting rod (10), and the protrusion (11) is movably arranged in the waist-shaped groove (12); the eccentric wheel (8) rotates, drives the sliding cover (14) to swing through the connecting rod (10), and then drives the probe (13) to swing, so as to adjust the incident angle of the probe (13).

2. The guided wave excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 1, Features: The eccentric wheel (8) is detachably fixedly connected to a connecting ring (9), the connecting ring (9) is coaxially arranged with the eccentric wheel (8), and the protrusion (11) is fixed on the connecting ring (9).

3. The guided wave excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 1, Features: The mounting seat comprises a fixing plate (2) and a V-shaped plate (16); the bottom surface of the V-shaped plate (16) cooperates with the outer wall of the grounding rod (1), the fixing plate (2) is fixedly mounted on the top surface of the V-shaped plate (16), and the connecting shell (17) is fixed on the top surface of the V-shaped plate (16).

4. The waveguide excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 3, Features: The probe (13) and the sliding cover (14) are threadedly connected; the connecting shell (17), the sliding cover (14), the V-shaped plate (16) and the grounding rod (1) form a coupling agent cavity (20); the output end of the probe (13) extends into the coupling agent cavity (20) and points to the axis of the grounding rod (1).

5. The waveguide excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 4, Features: Two rubber blocks (22) are arranged at the bottom of the V-shaped plate (16) to increase the sealing performance between the V-shaped plate (16) and the grounding rod (1).

6. The guided wave excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 3, Features: A square groove (15) is provided on the fixing plate (2). When in use, the fixing belt (5) is passed through the square groove (15), and the two ends of the fixing belt (5) are fixed, and then the mounting base is mounted on the grounding rod (1).

7. The waveguide excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 1, Features: An angle line (18) is provided on the connecting shell (17), and the angle line (18) is used to indicate the tilt angle of the probe (13).

8. The waveguide excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 3, Features: The sliding plate (3) is connected to the fixed plate (2) in a limited sliding manner; a threaded rod is rotatably mounted on the fixed plate (2), a connecting block (23) is threadedly connected to the threaded rod, and the connecting block (23) is fixedly connected to the sliding plate (3).

9. The waveguide excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 3, Features: An adjustment scale line (24) is arranged on the fixing plate (2) at a position corresponding to the connecting block (23).

10. The guided wave excitation device for detecting the damage state of the grounding material of the power transmission tower according to claim 2, Features: A threaded hole is provided on the connecting ring (9), and a fastening screw (27) is screwed into the threaded hole to abut against the eccentric wheel (8), thereby fixing the eccentric wheel (8) and the connecting ring (9); the spacing between the protrusion (11) and the motor (7) is adjusted by matching the fastening screw (27) with different positions of the eccentric wheel (8).

Images